mocum sum ED 126,343 CE, 007.479 TITLi FiremantlavalRateTraiang.Manuil and Nonresident Career Course. INSTITUTION Naval Education andTraining. Command Pensacola, Fla.' 'REPORT NO NAVEDXRA-10520-E PUB DATE 76 NOTE 248p.; Photographs will not reproduce in microfiche AVAILABLE FROMSuperintendent'of Documents, W.S. government Printing Office, Washington, D.00.20402/(Stock Number 0502-LP-052-6010)
EBBS PRICE MP-$0.83 HC-$12.71 Plus Postage* 'DESCRIPTORS, *Engineering;.*Engineering TeOhniciAns; Engines; *Equipment Maintenance; Fluid,tower Education; Hydraulics; *Job Training; Manuals; *Occupatidnal Information;'Ocean Engineering; *Study Guides IDENTIFIERS *Navy
ABSTRACT.
, The Rate Training Manual and the Nonresident Career CoUrs0 OWNRCO-was prepared to assist the firemanapprentice to gdalify and to advance to fireman intheNavy. The Manual is designed foVi.ndividual study and. provides subject matter that'relates directly the occupational qualifications of the fireman rating. Fireman is one of the lower ratings in the eng4sering department, which is organized for the efficient operationiMMAntenance,and repair.of the ship's propulsion plant, auxiliaty,Michinery, and .piping systems. The areas covered inclmdell(1),administrativeand operational functions of the engineering departMent;(2) various laws. t.andjAlenomena of nature related to ongineeringfundamentals;(3) TprinciVles and types of ship propulsion; (4) areas ofoperation in basic steam cycles;(5) operating principles. of boilers; (6) components of 'the steam ;turbines and reductiongears; (7) location °Eind'function of auxiliary machinery and equipment;(8) measurement% instruments;-.(9) pumps, valves, and piping; (101 diffeient shipboard elettrical eqmipment; (11) internal combustion engines.;and (12) engineerihg watches and duties. A glossary of engineeringterms and the metric system are appended and an index is-imcluded.A series of six assignments is provided in the NRCC to assist thestudent through the training manuals (Author/BC)
**************************i******************************************** * Documents acgeed by ERIC include many informal unpublished * * materials,not ava lable from othersources.,ERIC makesevery effort * * to obtain the best copy available. Nevertheless, items ofmarginal. * *'reproducibility are often encountered and-thisaffects the quality * * of the microfiche and hardcopy reproductions ERIC makes available * *viathe.BRIcDocumentReproduction Service (EDRS).,EDES is not * * responsible for the quality' of the original document. Reproductions* * supplied by BURS are the best that can be made from .the original. * *********************************************************************** O
JUL 0 1 FIREMAN 1976
NAVAL EDUCATION ANDTRAINING COMMAND RATE TRAINING MANUAL AND NONRESIDENT CAREERCOURSE
U S OEFARTMENT OF HEALTH. EOUCATION IL WELFARE NAVEDTRA 10520-E NATIONAL INSTITUTE OF EOUCATION THIS DOCUMENT HAS BEEN REPRO- DUCED E RACILY AS RECEIVED FROM THE PERSON OR ORGANIZATION ORIGIN. ATINr, IT POINTS Or VIEW OR OPINIONS STA TEO DO NOT NECESSARILY REPRE- SENT OFFICIAL NATIONAL INSTITUTE OF EOUCATION POSITION OP POLICY 1111 PREFACE
This Rate Training. Manual.arid the 'Nonresident CareerCourse (RTM/NRCC) has been prepared to assistthe Firemen Apprentice toqualify and, to advance to Fireman.Study of this training manualshould be combined with practical experience,with study and review of other applicable Rate Training Manuals,and with study ofmanufacturers' tecloical manuals, NavShipsTechnical Manual, and other material. applicable Cr Designed for individual study andnot formal classfoom instruction; the RTM provides subject matterthat relates directly to the occupational qualifications of the Fireman rating. TheNRCC provides the usualway of satisfying the requirements for completingthe RTM, -The set of assignments in the NRCC includes learning objectivesand supporting items designedto lead students through the RTM. As one of the Rate TrainingManuals, Flreinani and the NRCC has been prepared by the Naval Education andTraining Progam Development Center, Pensacola, Florida, for theChief of Naval Education andTraining. Information providedby numerous manufacturers,publishers,and associationsis gratefullk acknowledged. Technicatiassistancehas been provided by the Naval Sea SystemsCommand, Servi0 School Command, San Diego, and the Service School Command,Great Lakds.
Stock Ordel3ing -No. Revised 1976* 0502-1.14,2-6010
Published by NAVAL EDUCATION AND TRAININGSUPPORT COMMAND
o
UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON, D.C.: .1916 THE UNITED STATES NAVY
'GUARDIAN OF OUR COUNTRY The United States Navy is responsible for maintaining control of the sea and is a 'ready force on watch at home and overseas, capable of strong action to preserve the peace or, of instant offensive action/to Win in war. It is upon the maintenance of this control that our country' glorious future depends; the United States Navy exists to make it so.
WE SERVE WITH HONOR Tradition, valor, and victory are the Navy's heritage from theigtist. T.o these may be added dedication, discipline, and vigilance as thewathhwords of the present and the future. N Athome orondiStant stations we serve with'prideeconfident in the respett our country, our shipmates, and our families. Our responsibilities sober us; our adversities strengthen us. Service to God and Country is our special privilege. We serve with honor.
THE FUTURE OF THE NAVY The Navy will always employ new weapons, new techniqueS, and grotter power to protect and defend the United'States on the sea,'under the Seaj and in the Now and in the future,' control of the sea gives the United States her greatest advantage for the maintenance of peace and for victory in war.
, Mobility, surprise, dispersal, and offensive power are thekeynotes of the new Navy.The roots of the Nally lie u a -strong belief in the future, in continued dedicatiorito our tasks, and In reflection onour, heritage from the past. Never have our opportunities and our responsibilities beengreateil: CONTENTS
CHAPTER Page 1, Prepafinglor Advancement 1
2. Engineering Department IV4 4
i 3 Engineering Fundamentals, .' 4 ." 17 '4, 'Ship Propulsion . . ..., .. . . . 31
5 Basic Steam Cycles . { ...f. .. .. 48 , v 6. Boilers . le . . .4 .1. , 56
IeductioI 7. Steam Turbines and h Gears 72
8. Auxiliary Machinery and Equipment 88
9. InstruMents ' ...... 4 4 4 : 100
10. Pimps, Valves, and Piping..,. 116
1 1 . Shipboard Electiical Equipment...... ,. 143 itti . 12. Internal Combustion Engines . . 156
13. Engineering Watch4.... 171 APPENDIX
I, GlossaryEngineeri4 Terms 177 II The Metric System . 1.0 INDEX 193
Occippational Standards . * .. '197 Noniesident CarPer Course followSOccupational Stdards ......
'CREDITS-
The illustrations indicated below are included in this edition of Fireman through thecourtesy of the designated . companies, Diu rs, and associations, Permission to 'use these illustrations is gratefully acowledgect Permission to reproduce these illustrations and other materials in . this Publication should be obtained from the source.
Source Figure
Babcock & Wilcox Company 6-16C
Buffalo Meter CoMpany 9-16, 9-17
Cooper-Bessemer Corporation 4-12
Crane CompanY 10-15
Ciosby Valve & Gage Corripany 9-6
General Electric Company 7-14, 7-15, 1.2, 11-3
General, Motors Corporation 12-6 Detroit Diesel Engine Division 4-13 Electro-Motive Division 4-8
James Go Biddle' Company 9-21, 9-22
Jones Motorola Company 9-20
Manning, 'Maxwell & Moore, Inc. 9-1, 9-2, 9-3, 94, 9-5
U.S, Naval 1nStitute 54, 7-5, 7-6, 7-7, 741, 7-12, 7-13, 7-16, 8-5, 8-6, 8-7, 8-8, 9-7, 9-8, 9-11, 9-12, 9-13, 9-23, 10-9, 10-16, 10-17, 10-24, 10-27, 10-28, 10-29, 10-31
Westinghouse Electric Corporation 5-3, 7-10, 9-19
1V PREPARING FOR ADV
Study of this training manual willstart yoU distillinplants, and on your way to earning one of the Engineering mpressots. You will be requireto perfOrm entive corrective and Hull ratings, (See fig. M.)This training mainte 'ante in accord manual is one of several which will, ith th-M system. help you (For, ad itionalinformatioOn thisstem, :refer meet thetechnicalrequirementsfor to BaseMilitary Acquirements, NAVEDTRA advancement. 10954- Chapter 16.) YoU will also' stand As a member of the engineering department security and fire watches in engineeringspaces, aboard ship, you know thatyou are assigned to act asboat engineer, take part in drills,and the heart of the ship. It is throughyour efforts perfo the duties'," of damage control repair e eortsit f every other member ot,the arty te ephone-talker andmessenger. .. ePattment thatur ship beconies 'alive and is You .may ask yourself the question,"flovi le to meet its .'comitments anywhere on the 'am I ev r going to learnto do all these jobs?" In oceans of the world, 'the. beginning, you Will workwith the iietty officer Who is responsible for seeingthat a specific job 'is done properly.He will show you RATE OF FIREMAN exactly how to performevery detail of each operation. Then he will haveYou' do the job A Fireman" is basicallyan engineering trainee\under his supervision, Finally, whenhe has who must performa wide variety-ottasks. Some N.Jconfidence in you and your abilityto do the of these tasksmay seem quitennnecessatY job, he will giveyou the opportunity to perform although there is avery distinct reason for the on your Own. This general procedure' willbe tasks you will be required toperform. The observed thronghoutyour entire period as a reason, even though it sometimes may be 'striker, I unclear, is to increase the operational ickliness In addition to 'meeting theie requirements, of the ship and tb furtheryour *ping. you Will? also:' be required to have,a basic Everyday throughout your Navycareer, y it will knowledgeofmathematicsand.blueprint learn something new to'increaseyour, kno edge reading. Sources of informationwhich will be and to make you more valuableto yoursel, and useful in learning about these subjdctsare listed to the Nail,. later in this chapter. You .must be able to.serve as: a competent assistant to the petty officers holdingany of the 10 ratingi-ii,.!the engineering ADVANCEMENTAND department. (These ELIGIBILITY REQUIREMENTS ratings are discussed in chapter 2 of thistraining Manual.) YOu will learnto operate pumps, motors, and 'Before you candvalice inrate, you must turhiiies;to . read gages and fulfillcertain litaryandprofessional thermometers; to maintain and clean eng,ines, requirements. 'machinery, and compartMentsi and to identify . Naval requirements for advancement ,refrigeration are, equipment,anchor. windlasses, those general standards applicable tball enlisted FIREMAN "s
fr MACHINIST'S MACHINERY , BOILER FIREMAN MATE "(MM) -REPAIRMAN (MR) TECHNICIAN RECRUIT (FR) (BT)
/1111 0. .% III 1 11
ENGINEMAN (EN) ELECTRICIAN'S BOILERMAKER (BR). MATE" (EM)
FIREMAN APPRENTICE (FA) AIL
HULL MAINTENANCE MOER (ML)' I. G. CTRICIAN (tC) TECHNICIAN (HT) 4k y.
FIREMAN PATTERNMAKER YSGTAESMTECHNICIAN (FN) (PM) . (OS)
3.10 Figure il.Engineering and Hull Ratings.
a 2 Chapter' 1-- PREPARINGFORADVAlsICENT personnel, such as watch standing,first aid, and military conduct.You must Factorsor entering show thatyou are . additional practical proficientin each ofthe asthe y'+ are fa, ors specified for naval standards ,publishedin changesto. the the next higherpay grade. These OccupationalStandards Manual. are discussed in Military PracticalFactors The Record of Requirements, alsoprovidesspace NAVEDTRA 1054-D. recordingdemonstrated for which are within proficiency inskills Professional reqtiirementsfor advancement but which the general ctf the rating are technical standards,,that are not identified to the work of are directly related 4 minimum each rating. - occupational standards. .. . If you Boththe are transferredbefore you naval. ;requirementsandthe all practicalfactors, the quaff in professional-requirements NAVEDTRA 1414/1 subject aredividedinto forwarded: withyour service is matter gsoupi,which `record toyOur next- subdivided into arefurther. duty station,.You can practical.factor&and trouble by save yourselfa lot of factors. Practical knowledge making sure thatthis form is factors arethings thatyou inserted inyour service retard actually must be able todo. Knowledge before. youare minimum things factors are the transferred. Ifthe (Om is you suit know record,you may be ,not in, yourservice perform your'duties. in order to required tci,start all again andrequalify in the over ,The p ofessionaland naval .have already practical factorswhich discussed requirementS just been checkedoff, re listed in theManual of, NaVy The Navyhas Enlisted M requirements 'that establishedcertain' npowerand PersonnelClassifications mpst be met and Oci.upationalStandards, eligible, to beforeyou are (with NavPers 18068-D taketheexamination changes).:Aii&4manual provided edyancement. Youmust for minimum requipments the , pay for adVancementto each de within eachrating. First:Meet basic length of requirements;such as :The.- , ards for Fireman service inpay grade and this man ala d they were form the basisfor Second: Have total service. current at the a statement inyour service this pring. However, the date of record thatyou satisfactorily standards 'change practical factors 'performedthe, occasion ly,andthe for` thenext higher advancement questionsinthe Third:Have a pay grade.' aminations forall pay grades . record that statement inyour service based on thelatestlevision. are you successfully before taking Consequently, long taking manual completed the an examinationfor advancement,' for thenext higher you should'Cheek fOr advancement. level of yourself that revisions.' and\assure ,,,- Fourth: your knowledge Berecommended latest standards. covers 411 the commandingofficer. byyour A special formknown as the PRACTICAL RECORIOF When yousatisfy all of these FACTORS, youare requirements, is used tokeep a recordNAVEDTRA 1414/1, eligibletopaiticipat of yourpractical factor examination.. If inthe standards.The formlists all you pass theexa tion with both practical factors, high enoughscore, your command' a . militaryandprofessional.As you , the authority to g officer has demonstrateyour ability. advance you in rate. ' practical factor, to performeach 1, appropriate entries 4. the DATEand INITIALS are made in divisiOn officer columns bythe SOURCES OF or your dupervisinipetty officer. INFORMATION Since changes are made periodicallyto the The Navyhas set definite Manual 441,,f .limitson the Navy EnlistedManpower and material forwhich you-are PersonnelClassifications examination. accountableon the Standards, and ccupational Thesourcesfrom revisedforms. of NAVEDTRA examination itemsare taken whith 1414/1 are listed, inthe are provided wit*necessary. Extra Bibliography for space is providedon the Record 10052. This Advancement,NAVEDTRA s:3f Practical bibliography isavailable ship or station.It is revised on your annually, sohe-sure FIREMAN, '- Sr itEWARDSOFADyANCEMENT edition. it providesthe to consultthe current of many ofPublicationsandsections Each time youadvance, you receive titles shOulk studywhen rewards includehigher pay and publicationsthat you rewards. These pension preparing for theexamination. TI%publications allowances togetherwith additional all,the standards retire,But thereally lisfed containmaterial covering An benefits when you tunities for more . listed in theOccupationalStandarckManual. inportant gainS are oppo the trainingmanual or andchallengingassignments, asterisk (*) identifies before you can interesting Superiors as well as , . manuals that youmust complete increased respectfrom your theexaminationfor supervise 'or help,and th; beeligibletotake from the men you, Chance for greaterfulfillment of your abilities. advancement; useful thinks your anlearn afforded theopportunity to '. One of the most it. Above all,,, you are is how to findout More about conunancl, your,Wavy, and your 4 about a subject give you allthe Serve your responsibility in a No singlepublication can country at ahigher level of need. to know toperform your job. information you 'be more important Navy, you training manualswhich' As a men:theta:theUnited States duties. Basic 'advancement knowing that, as you helpful to you as you.prepare for have thesatisfaction of below. your pettyofficers will assist serving your countryin .a most are lifted advance, you are all times, obtaining other sourcesof information. important way. Doyour job well at you in do and hoW youdo and take pridein what you Uses, NAVEDTRA10085-B country is aspecial privilege. Tools and Their it. Service to your with You must makeevery endeav ?t to serve Sketching, '. BluepriNtReading and honor. , and victory arethe Navy's NAVPERS 10077-13 Tradition, valor, outstanding Thelonghistory of section in theAppendix of this heritage. 'noble service of.the Navy The glossary of achievements and isanother good source inspiration and achallenge to you training manual ordifficultto provide an to you tohelp information.Unfamiliar` and yourshipmates. It is up engineering terminologywhich has enlarge the ,prestige and the understand is defined in this maintain and ii:r.1 been usethroughout this text traditions of thenaval service. section.
° le
1
10 CHAPTER'2
ENGINEERING DEPARTMENT
,'The, engineering, ratings cover alrphases of "department which will concerned with the -operation, maintenance, and repair of maehinery operation and maintenance ','of' the propulsion and equipment under the cognizance (continD Plant of the repair ship or, tender, Smallephips, oftheengineeringdepartment. To fully because of the smaller number-of engineering understand the nature of your new assignments ratings abOarcl, .will Combine many ratings into a asaFireman, youmust understand the single division, . , organiza f the engineenng department and Figure 2-1 shows.the organization structure be familiar with the scope, of each., Group VII of the engineering department aboard a lar$0 (Engineering and Hull) Rating. . ship and the functions 011ie various divisians of Inthin,, chapterweShalldiscussthe the 'department,- ,-Remember; thatthis administrative and operational functions of the organization .does not represent a particular type engineering _department .and the Group or, class of ship. It 'should 'be ,noted that the Ratings. administrative assistant, the department training Officer, and the special assistants arenicles to, the engineer officer and these' responsibilities, are ORGANIZATION OF' often 'assigned as ,additional duties" to officers ENGINEERING DEPARTMENT, ,functioning in' other capacities at any. of the
, levels in the direct chip of command. The engineering department is organized for- Thethreeprincipal assistants to the engineer the efficient operation, maintenance, and repair oftheship's officer age the .main .proprilsion assistant, the propulsion,plant, . auxiliary damage, cOntror assiStanty; and the' -electrical machinery, and-piping systems; In addition, the - officer.; Each, Of-;'lliest;.'aSsiatants, '- in' 'turn, engineering department is resPonsible'for (1) the adrainisterS those' divisionS!assignedna,hrdicated, controlof damage, (2) the, operation, and on the Organization :chart': Maintenance ofelectric , ',generators and- distribution Systems, (3) repair to the ship's The division, officer is -rtispansible, for the and (4)1or general shipboardretiairs. ,Organiza "on of his division; The Watch, Quarter, and $ta 'o ill reflects the organization of Theorganizationoftheengineering division by sec ores and shows ,the ,assignments departmentisestablished bythe'slip's for all einergen4 d The -billets-, asSigned Organization book,, This organization is made up depend upon the comp Merit ;the:division of a number Of divisionS whose functions..are and the capability of-Personnel assn d, to the'. - discussed laterin this chapter.. , The organization of the departinent will vary according to .the size of the. ship apii the ENGINEER OFFICER 'engineering plant, Forces 'afloat, ;are primarily concerned with repairs, ; will hive The engineer officer.'..isi, the head. Of the repair department consisting of MAO of the i e,,itiOe,:eringdepartMent.,, 'addition' to ,the, engineering ratinT, in addition totairienginiering duties of idepartinenthead,the' engineer officer 4,
'.SPECIAL ASSISTANTS,
ENGINEERING TRAINING OFFICER ' FIRE*ORAL.. GA$'FREE ENGINEER 4, NBC DEFENSE OFFICER
_ 1 AriAGE cottrwill, 4ststAto
R DIV' , AbtV OFFICER- , OFFICER
ASSISTANT , .
.responsible the 'Operati*,...oare;, -arts' TO' s Pet;ise00' :',opera tiOn "of, cthe maintenance '411.444)P4Isioil. ' au& ,deP4n di4sutigioofic4,ensuring the Ogehhiefyl the control :,of " damage .,'and, :;assigned: office:spaces:A*1 'the accomplishment 'Ofpairi:itithin AhoT'aUPiOity ' cafe, rid upkeep of, office equipliente, .of 'theshops':i',-the, eugineeFiUg 2. To and ,directthe department Ye,OUiph,, and respon sibilities; cif the',Ogineer,'Offieci 00, ` I screed shreri ';14$,('', ostavi jZiguldtions!,` and footed_ to ,onaiteCr -6,ffitia4 and initiate f%),iga#11;#1an finctRegyfrOfi fonirk(000 CL, iiotiou,Whitt:upPropritite to screen and , r ensure ft cPP`Os*Iliclance. DttoAitNENt.-AitgaNOTRAilyE- xu prepLion 'or .,,,. A400 epartmeilt-.0itectiyeaaM;Idlloiring,Telea*bY,' the engineer' i fficer ekiitisi'eoritrol-hveflheir administrative isskianpef..z': function "as 'an" ide 'to the:010k0ei,' dtkir de0qtiteut.'ke6i4s",i14(1,1010:', fickler fib anddOtiel'aie,as follO*az 790 . 1111'X.; Chapter 24ENGINBERING DEPARTMENT
6. To coordinate the preparation of the MAIN PROPULSION ASSISTANT department in-port daily watch hill. 7. 'To assign itasks to, and evaluate the The main .propulsion 'assistant is responsible, 'Performance ofclepartment Yeoman and other under the engineer officer, for the operatjo$ enlisted personnel assigned to the department care, and maintenance of the ship's propulsion machineryandrelated office. ° auxiliaries,ff4has cognizance Oyer the care, stowage, and use of hi an engineedngderctinent 'fuels and lubricating oils. The preparation and. where an care ..of the Engineering ,Log and Bell Batik are administrative assistant billet is not 'provided theresponsibility within the framewor of the ship'seorganization, of themainpropulsion the engineer officer, may assistant, as is .the preparatiof of operation, and elegate the duties of maintenance records and procedures., such a billet to co ten !son. pi- Machinery Division DEPARTMENT' TRAINING. OFFICEIV If you are assigned to the M division, you will 'probably work in one, of the'enginerooms. The-duties of a department training Officer are generally performed by the engineer office/1 Normally, there is one engine for each of the or an assistant to the engineer officer. Some of ship's propellers. On ships with two or more enginerooms, 4;,1theengineroorns are generally these &dies are: '1" located immediately aft of the firerooms which . supply theni with steam. In an emergency, any. I.To'developadepartment yam engineroOm can be isolated while the ship program in support of -the training objective ,continues underway on the remaining engines. the ship. . T 2. TO implement approved*Itrainini plans And policies within the department. The B division operate's the boilers and the 3. Toelfrrco,ordinateandassistinthe auxiliaryfireroommachinery.if you are administration, of divisiontraining programs assigned to this division, your duty station may withinthed6partment,including:(a) be one of the firerooms. The firerooms are supervision/of thepreparationof training usually lbed amidships on the lower levels. materialsandreviewof curricula,training There mabe as many as 6 or 8 firerooms, courses, and lesson plans; (6)assistin the depending n the size and type...of ship. In ships selectionandtrainingofinstructors;(c) having more than one ffferoereach fireroom observation of instruction given.. at drills, on generally has two boilers installed either facing watch, on ,station,. and., intheclassroom, each other, or side by side. The boilers are so followed .by recomendaVons to the engineer arranged that any -number of them can be used officer;.. (d) procurement; through the ship's to 'supply steam to- the ship's engines. The'- training officer, of required training aids and firerooms are separated by watertight bulkheads devices includinVIms, projectors,training` so that any fireroom iliay be paled off while the courses, and books. ship operates-on the remaining boileri. - 4. To maintain depk.rtvnt training record On your first trip though 'the fireroom you .,and training reports. may wonder why there are so maim/ lines and valves: You will become familiar with a few of 5. To disseminate 'information concerning them at a time, and by paying strict attention the availability of fleet and service schools. you,, will gradually learn how all of them are e used. 6, Toinitiaterequisitionsfortraining "i Steam, water, fuel oil, or air may be carried plies and materials, subject to the approval of in these lines. The lines which carry steam or engineerRfficer. water are covered by insulation and lagging for FIREMAN
personnel' safety and to prevent heat loss and Repair Division condensation. Lines are stenciled to indicate the iii
fluid carried and the direction of flow. The Rilivision is responsible for maintaining. These lines do not run through the ship at the watertight" integrity Hof the ship, The it ,random, but connect the units of the systems division consists of the hull maintenance shops, according to a definite plan. In the course of If you are assigned to this division you will work your training you will trace these lines from one in one of these shops. unit to another throughout each system. The All 'damagecontrol ' andfirefighting 'ship's blueprints and drawingsare of particular equipment aboard ship is maintained by the R value in tracing out systems in the engineering division. Much of the training of petsonnel in plant. damage control iscarried on by R. division personriel, DAMAGE CONTROL ASSISTANT ELECTRICAL OFFICER ./ The damage control assistant is responsible, under the engineer officer; for the prevention The electrical officer is responsible,. under and control of damage, including control of theengineerofficer,fortheoperation, stability, list, -and trim. Conditions of-closure, maintenance,andrepairof theelectrical, watertight integrity, and compartment testing machinery and,systems throughout the ship. The arecarried out under his supervision. The maintenance. of the ship's power and lighting damage control assistant (DCA) administe0 the systems is the primary concern of the electrical " training of the ship's personnel in damage officer. Repair shops are provided on larger ships control, firefighting, emergency. repair work and for extensive repairs to eleCtrical equipment nonmedical defensive measures against NBC The IC system, under the electrical officer, is \a attack. The hull maintenance shops and the part of the E division. machine shop are under the cognizance of the The E diirision -has charge of generators, DCA. In these shops, all necessary repairs to the gyrodomOasses, intercommunications, and' other hull and the ship's b9ts, within the shop's electrical equipment. The generators in the capacities, are made by' 14-assigned personnel. engjneroonis provide electricity for power and light. The steam turbines. Which drive the Auxiliary Division generators are operated by 'the .ivision: On electric-driven ships, the E divisionso operates Personnelof A divisionoperatethe the main, generators and main ele trio motors refrigeration plant, air compressors,. emergency which turn the ,shaft. If assigned to this division, fire pumps, emergency diesel generators, and the you 'might work in the Main motor rooms, the ventilation,heating,andairconditioning enginerooms, the electric repair shop, or in the systems. They are the boat engineers in small IC rooms. boats and maintain the ship's steering engines. If you are assigned to this division, you may be NBC DEFENSE OFFICER stationed in the auxiliary-SOces or in any other part of the ship where the auxiliaries under A i Since nuclear, biological, and chemical (NBC) -division are located. - defense procedures are classified and subject to The refrigeration plant, similar in many frequent modification, it is best to refer to respects to the home refrigerator preserves the current OpNav Instructionsfor a detailed supply of fresh foods and provides ice for description' of the NBC defense officer's duties.. general shipbOarduse.. .The air compressors, In general, the NBC defense officer (collateral supply compressed air for pneumatic tools, for dutyofthe damage controlassistant)is cleaning parts of machiriery, for diesel engine air responsiblefor thetrainingof shipboaid starting systems, and for various other purposes. personnel in defense against NBC attack. He is The equipment assigned to the A di.v4ion is alsoresponsibletorthe Iprocurement, located throughout the ship. dis ibut ion,.maintenance of NBC defense Chapter 2ENGINEERING DEPARTMENT . equipment.Inaddition,hemustensure 4. Prepare enlisted perforniance evaluation decontamination of personnel, equipment, and sheets for personnel of his division. theship;andthemanagement and transportation of NBC casualties with the advice 5. Maintain a division notebook containing and assistance of the medical officer. personnel data, cards, training data, a space and equipment responsibility log, the watch and battle stations to be manned, and such other FIRE MARSHAL data as may be useful for the orientation of an officer relieving him,and for ready reference. The litunarshal, under the engineer officer and the damage control assistant, is responsible 6. Be responsible for all forms, reports, and for the maintenance and readiness of the ship's correspondence originated or maintained Vi.'his firefighting equipment. He is also responsible for division.. the prevention and elimination of fire hazards in 7. Establishandmaintainadivision the ship. organization manual and other directives which may be necessary for the administration of his GAS-FREE ENGINEER division. The duties and responsibilities of the gas-free 8. Ensure that, presciibed secur4measuresj engineer are given in chapter 9920 of Nav Ships are strictly observed by personnOofitis divisien. Teel:Weal Manual. Briefly, the gas-free engineer 9. Mgice recommendations for personnel tests and analyzes the air in compartments or transfers ard changes in the division allowanee itoidsthat have been closed and are being to his department head. opyned for inspection, to determine whether such, spaces aresafe for personnel to enter 10. Porward requests for leave, liberty, and without danger of poisoning or suffocating. He special privilege and make recommendations also determines whether itis safe to perform for their disposition. "hot work" (welding or cutting) within, on the I. Conductperiodicinspectionsand exterior boundaries, or in the way of such spaces exercises,andmusterstoevaluatethe without danger of fire or explosion. (The person performance and discipline of his division and to designated as the gas-free engineer must have the initiate disciplinary action, when he deems it qualifications set forth by NaySeaSysCom. necessary, in accordance with the Uniform Code ofMilitaryJusticeandotherregulatory' DIVISION,OFFICERS directives.
In addition to the duties as set forth in U.S. TECHNICAL ASSISTANTS Navy Regulations, the Sip's Organization and Regulations. Manual generally prescribes that a The duties of technical assistants (1430, diVision officer shall: Warrant Officer, E-8, and .E-9 personnel) vary with the' different specialities.In. general, a, I. Directtheoperation of his division technical assistant's duties and responsibilities through leading petty officers, as prescribed in apply to the operation, maintenanee, andre,pair the division organization. of machinery, equipment, and systems under the 2. Assign personneltowatches and duties coknizance of the division to which the teehnical within the division (develop rotation programs assistant is asiigned. for battle stations, watches, and general dutieq, tolnesniathetraining andproficiency of ENLISTED PERSONNEL assiga personnel).4 3. Ensure that division personnel receive In addition to the general ratings for enlisted indoctrination, and military and professional personnel of the engineering department, there. training. are specific billets or assignments which require FIREMAN
special Mention. Three of these billets are the oil ''Boat *Engineer and water king, the movie operator, and ,the boat engineer. Firemen, Enginemen, or Machinlit's Mates from the A division are detailed as boat Oil and Water King engineers. Boat engineers °pc:rate, clean, ,iand inspect the parts of the boats Vssigd to them, On a large ship, the billet for oil and water Boatengine* repairsareunder kenby king is usually divided into two billetsone for "'Enginomdn assigned to That duty, ! the fuel. oil details, and the other for potable (fresh) water and feed water, The oil and water king is a boiler Techniciah ENGINEERING DEPARTMENT on steam-drivenshipsandisgenerally an RATINGS. Engine ma non'diesel-drivenships.His After serving as a Fireman for the required responsibilities.are as follows: length of4.thne, you may strike for a third class petty officer's rating, But, first; Yop must make . 1,Supervising the operation of all valves of arrOportant decision;You may choose any of the fuel oil system, the transfer and booster 10' ocifferent ratings. The 'decision you make will pumps, fuel oil manifolds, fuel oil heating coils determine largely the kind of work you will be as necessary, and the fresh Water system as doing throughout 'the balance of your Navy prescribed by the casualty control' bills for those career. Systems. rk Ingeneral, Rthe tt'engineeringdepartment. ratingsrequire ;:..art' aptitude'forthings 2. Properly maintaining fueloilservice mebhanical,adegreeof oficiencyin tanks, and shifting suction among service tanks. mathematics and physics, and sme experience in repair Work. A knowledge of mechanical 3.flintaining the .distribution of fuel oil drawing is also desirable, Rate Training Manuals and wateso that the ship will remain on an and Nonresident Career Courses covering many even keel and with proper trim. spectsofbasic- engineeringareavailable. Self-reliance, ingenuitk; and resourcefulnessare 4. Preparing fuel and water reports. particularly important to any man striking ffir an engineeringrating. `' 5.Testinganti recording the alkalinity, Schools for engineering ratings are available chloride content, hardness,'nnd other properties to those who 'can qualify. The various 'types of or -feed and boiler water, and making required schoolsarecoveredinBasicMilitary tests of fuel oil.,Detailed information concerning Requirements, NAVEDTRA,.l 0054-D. A list of such tests can be obtained from NavShips all schools and their requirements is given in the Technical Manual, chapter 9550 for oil tests and Catalog of Navy Training Courses (CANTRAC), chapter 9560 for water tests. NAVEDTFtA. 10500. The titles and job descriptions of the .various. 6. 'Refer. to Basic Military Requirements, engineering department ratings are given in the _NAVEDTRA 10054-D, for information on sections which follow. safety precautions to be observed .vvh to handling fuel oil, MACHINIST'S MATE(MM) Movie Operator MachinisITMates operate and maintainthe propulsibn turbines, reduction gears, condensers, Movie operators are generally graduates of a air ejectors, and such miscellaneous 'auxiliary Sound motion picture school or duly qualified equipment in the engineering spaces as pumps, by competent authority. Provision is generallk air. compressors, generatots, evaporators, valves, made to have a sufficient numb& of operators oil purifiers, oil and water heaters, governors,- to accommodate the ship's needs, 16andpropeller' shafts.Figure' shoWs a Chapter 2ENGINEERING DEPARTMENT
Machinist's Mate recording readings froman e orator. ENGI EMAN (EN) Enginemen operate and maintainpower plants used to operate, shipboard auxiliaries and topropel boats andships.In addition to workingwithinternalcombustionengines (diesel and gasoline), Enginemen must know how to operate, maintain, and repairmany kinds ofshipboardauxliaryequipment. equipment 'includes'refrigeration %andandair Conditioning systems, pumps, airccompressors, andvarious kinds of hydraulic equipment.: Figure 2-2.Machinist's Mate recording evapdator Figure 2-43 shows an Engineman standing witch' readings. 139.1 on a diesel engine.
1 Figure 2-3.Engineman standing watch on a diesel engine. 139.2
.11 k FIREMAN
.1
139.3 Figure 2-4. Machinery Repairman operating a milling machine.
MACHINERY REPAIRMAN (MR) highestorder.Often,intheabsenceof dimensionaldrawingsorotherdesign Machinery Repairmen makealltypes of inkrmation,aMachineryRepairmanmust machine shop repairs on shipboard machinery.,- depend upon his ingenuity and know-how to This wOrk requires the skillful use of lathes, successfully machine a repair part. Figure 2-4 milling Machnes, boring mills, grinders, power shows aMachineryRepairman operatinga hacksaws, drill Oresses, and other machine tools, milling machine. aswellas'allhandtools' andMeasuring instruments uSlially found in a machine shop.. BOILER 'TECHNICIAN (BT) The job of °restoring machinery to good working order, ranging)gsAt does from the fabriOation of The Boiler Technicians operate all types of a simple pin rr3r.1i nk to the complete rebuilding marine boilers and firefoom machinery (pumps of an intricate gear system, requires skill of the and forced draft blowers). They transfer, test,
f2 Chapter 2 ENGINEERING .DEPARTMENT
Mid take soundings of fuel, and feedwater tanks, They also maintain and repair boilers,pumps, and associated machiary. Figure 25 showsa Boiler Technician removing an atomizer from-a burner. BOILERMAKER (BR)\. Boilermakerstest,maintain, and repaid marine boilers, heat eXchangers, and associated. equipment; inspect boilers and effect corrective measures; perform electric arc and oxyacetylene welding in boiler repairs; and maintain 'records and reports.
L ELECTRICIAN'S MATE (EM) Electrician's Matesstandwatch, on generators, motors, switchboakds, and control equipment;operate-searchlightsandother electrical equipment; maintain and repairpower and lighting tqlrcuits, electrical fixtures, iiiotors, .ginerators, distribution .switehboards,and other 139.4 ekttcttical equipment; test for-foundsor other Figure Boiler Technician removing an atomizer casualties; and repairand, ildelectrical from a burner. %eqtiipment- in an electricals Figure 20 i'df. -c
v.
I
Figura 2-6.An Electrician's-ate taking readin s oriiiirain switchboard. \ 13 FIREMAN
/7
29.137D Figure 2-9.A Patternmaker, sawing a pattern.
%Apr
139:6 Figure 2-7.Hull Maintenance Technician preparing to weld.
,1--
.74-T.442. """A
68.124 103.70 Figurd2-10.A MAIder finishing a core. Figure 2-8.Hull Maintenancetechnicianremoving damaged pinks. 20 r. 14 Chapter 2ENGINEERING DEPARTMENT
shows an Electrician's Mate taking readings at HullMaintenance the main switchboard. Techniciansare responsibleformaintainingandpreparing damage control equipment and for preserving INTERIOR COMMUNICATIONS watertight integrity, by suchmeans as adjusting ELECTRICIAN (IC) dogs and renewing gasketson watertight doors, hatches, scuttles, etc. Figure 2.8 showstwo Hj11I IC Electricians maintain and' repair interior Maintenance Techniciansremoving damaged communications(IC)systems,gyrocompass planks. systems, amplified voice systems, and alarm and warning systems, and related equipment; and PATTERNMAKER (PM) stand IC and gyrocompass watches. (An IC Electrician may be responsible for maintaining Patternmakers make wooden, plaster, and motion picture equipment aboard ship.) metal patterns, and other equipment usedby MoldersinaNavy foundry. They mount HULL MAINTENANCE patterns on match plates andon follow boards TECHNICIAN (HT) for production. molding. Pattern ers make master patterns; make' full scale 1 outs of On 27 February 1970 the Secretary of the wooden patterns,core boxes, and tem fates; and Navy approved the establishment of 'the Hull index and store patterns. Figure 2-9 illustratesa Maintenance Technician (HT) general rating and Patternmaker sawing a pattern. the attendant disestablishment of the Shipfitters general rating (and included service ratings), and MOLDER (ML) the Damage Controlman general rating. Hull Maintenance Technicians (HT) plan, Molders operate foundries aboard ship and supervise,and perform tasksnecessaryfor at shore stations; make molds andcores, rig fabrication, installation and repair of all types of flasks,prepareheats, and pour castings .of structures shipboard and shore-based plumbing ferrous, nonferrous, and alloy metals; shakeout and piping systems, qualify in the techniques, and clean castings; and pour bearings. Figure skills and use of damage control and firefighting 2-10 illustrates a Molder finishinga core. equipment, carpentry, nuclear; biological and chemical (NBC) defense; perform tasks in the field of shipboard damage control NBC defense OTHER RATINGS and firefighting; organize, supervise and train personnel in maintenance repair, NBC defense j In addition to the Group VII Engineering and damage control duties. Figure 2-7 showsan and Hull Ratings, you will be requiredto know HT prfparing to weld two pieces of angle iron some of the other ratings in the Navy. Figure t ogether. 2-11 gives you a chart of the Navy Ratings.
21
15 FIREMAN
GROUT I CICX let GA *EVA RD ^ U4 OT ST BOATSWAIN'S MAT! QUARTERMASTER RADAR/AA. SIGNALMAN OCEAN SYSTEMS TECHNICIAN SONAR TECHNICIAN yr. GROUP II ) ORDENANC NrFT TM NM yT GUNNER'S MAT! FIR! CONTROL TEHC/410AM TORPEDOsuur S MATIE MISSILE TECHNICIAN
GROUP CLICTKONICS DS DATA SYSTEMS TECIINICIAN EaRMICISTTECKNICIAN
GROUP PRECISION . ISMAINAEN 114TitAW4 CI:TICCZt A 6> RU TN FC SK DR RAD VAN YEOMAN PERSONNPNELMAN POSTALb. STOREKEEPER DISOURSING CLERK GROUP ADICIOSTRATIVE COAutUNICATIONS YEIMIAN AND CLERICAL X X C V Mf let CT DATA PROCESSING JOURNALIST WES 1111.0IMPIt SHIP'S SERVICEMAN COMMUNICATIONS TECHNICIAN TECHNICIAN Ault
GROUP VI IOSCELLANCOUS LI DM MU LITHOGRAPHER ILLUSTRATOR DRAFTSMAN MUSICIAN
giek MM EN MR EM GROUP VII HULL MAINTENANCE MACHINIST'S MATE ENOINEMAN MACHINERY REPAIRMAN I ELECTRICIAN'S MATE ESIGRIEERING TECHNICIAN ARO NULL
IC GS INTERIOR COVARINICATICNS DA! TuRoINE ML 144 OR ELECTRICIAN EC PI SE TRU A N !virtu tECHrocIAN MOLDER PAT TEMAAKIER GORE IDAAKER
GROUP VIII )181 CONSTRUCTION !A ED CM CE BU ENGINEERING EQUIPMENT SR CONSTRUCTION UT CONSTRUCTION BUIL DER AID OPERATOR STEELWORKER. MECHANIC UTILITIES MAN ELECTRICIAN
-4 -044- 11.4111r .4134- AO AT AQ AS AW AVIATION AVIATION AVIATION AV! TION .to AVIATION AVIATION MACHINIST'S DICHANCEMAN LECTRCNICS FIRE TROL ANtiSullmARINEMARFARE ANTISUBMARINE MATE CHNICIAN T NICIAN TECHNICIAN WARFARE OPERATOR
GROUP If AVIATION AZ PR AG AC AK AE AVIATION M RCREW AEROGRAPN ER'S AIR AVIATIONATK AVIATION MAINTENANCE SURVIVAL MATE CONTROLMAN STOREKEEPER ELECTRICIAN'S 1-QuIPMENT441 At MATE .414001. . Nil 4111CIII eM% PM AS PH PT AVIATION AVIATIO SUPPORT tRACITEDVMAN AVIAASTION PHOTOGRAPHER'S PHOTOGRAPHIC STRUCTURAL EC1A/ ENT BOATSWAIN'S MATE INTELLIGENCEAMN i MECHANIC TICHN AN MATE HC GROUP HOSPITAL MEDICIAL } 1" ...:.
GRISUPIO CIENT/1 , ,,TEDcHiplicAiLAN ..-.t
), 22 0 3.10 Figure2-11.Specialtyarks for enlisted ratings.
16 - CHAPTER 3
ENGINEERING F DAMENTALS
s chapter is designed to acquaintyou with v. ous laws and phenomena of with which the object is attractedto the earth. nature. Inertia is that physical property whichcauses Included is information pertainingto matter and objects that are at rest to remain energy, force and motion, heat and temperature, at rest, unless they are acted upon bysome external force; and pressure, combustion, the laws of perfectgases, which causes objects movingat a constant andsomefundamentalinformationabout velocity to continue moving at this Metals. The information provided constant here is general velocity, and in the same direction,until acted in nature; but it has been included to giveyou a upon by some external force. better understanding of how or whyengineering machinery operates or produces work. Asyou study this chapter, remember that anythingthat FORCE occupiesspaceandhasweightiscalled MATTER. Force is what makes an object startto move, or speed up, or slow down;or keep moving against resistance. This foitemay be either a PHYSICS push or a pull. You exerta force when yOu pdsh against a truck, whetheryou movethe truck, or Tlie forces of physics and the lawsof nature only try to move it. You also exerta force when are at work in every single piece of machineryor you pull on a heavy piano, whetheryou move equipment aboard ship. It is by these forcesand the piano, or only try tomove it. Forces laws that the machinery and equipmentproduce produce or prevent motion,or have a tendency work. to do so. A tendency. toprpventmotionisthe frictional resistance offered by MASS, WEIGHT, AND INERTIA an object. This frictional resistance is called frictionalforce. While it can never causean object to move, it The physical principles of mass and inertia can check or stop motion. Frictionalforce are involved in the design and operation of the Wastes power, createsheat, and causes wear. heat/ 'flywheels and bull gears thatare at work Although frictional force cannot in the ship's engineering plant. the great be entirely mass of eliminated, it can be reduced withlubricants. the wheel tends to keep it rotatingonce it has been set in motion. The high inertia of the wheel keeps it from responding to small fluctuations in SPEED, VELOCITY, speed and thus helps to keep the engine running AND ACCELERATION smoothly. Speed is defined as the distance covered The mass and the weight of per an object are not un't of time. Velocity is speed ina certain, the same. The mass of an object is the quantity dir ction: Acceleration, is therate at which of matter which the object contains.The weight vel city changes. If, for example, of the object is equal to the gravitational the propeller force shaft rate of rotation increases fromstop to 100
17 23 FIREMAN revolutions1 per minute (rpm) in 20 minutes, the Stored energyisenergythatis actually accelerationis5 rpm.In other words, the contained within or stored within an object. velocity has increased 5 revolutions per minute, There are two kinds of stored energy: potential during each minute, for a total period of 20 energy and kinetic energy. Potential energy is minutes. A body with uniforth mdtion has no energy within an 'object waiting to be released; accelerativ. When the velocity of an object' while kinetic energyis energy that has, been changes by the same amount each second or released. For example, potential energy exists minute, you have uniform acceleration. Uniform within a rock resting on the edge of a cliff, water deceleration is obtained when the decrease in behind a dam, or steam behind a turbine throttle velocity is the same each second or minute. valve. Kinetic energy exists because of the relative ENERGY velocities of two ocmore objects. If you puslre*,, the rock, open the gate bf the dam, or open the Energy may be described as the ability to do turbine throttle valve, something will move. The work. In the physical sense, work is doge when a force acts on matter and moves it. We use heat rock will fall, the water will flow, and the steam energy tq turn a steam turbine and electric will jet through the turbine nozzle valves. Thus thepotentialenergyis converted to kinetic energy to drive motors. The mechanical energy energy. of thepistonsinan automobile engineis transmitted to the wheels. by the crankshaft, Energy in transistion exists when the rock transmission, drive shaft, differential gears and hits the ground, the water hits the bottom of the rear 'axles. Nuclear energy is used to generate dam of the paddles of a water wheel, or when electric power and to drive naval ships. the steam hits the blades of the turbine rotor. Perhapsthe most common definition of In the examples just discussed, an external energyis "thecapacityfordoing work." souce of energy was used to get things started. HoWever, this is not quite a complete statement External energy was used to push the rock, to because energy can produce other effects which open thegate of the dam, or to open the could not be considered as work. For example, throttle valve. Thus, you see that one energy heat canflow from one objectto another system affects another energy system. There is a without`doing any work; yet heat is a form of tremendous amount of chemical energy stored eliergy and the process of heat transfer produces in fuel oil; but it will not raise the steam in the aneffect.Therefore, a 'better definition of boileruntil some external energy has been energy is "the capacity for producing an effect.". expended to start the oil burning. Energyis normally classified according to the size and nature of the objects or particles Energytati be measured. The most common with which itisassociated. "So we say that measurement of expended energyis in work mechanical energy is the energy associated with units of foot-pounds. When an object has been large objectsusually things that are big enough moved through a resisting force. work has been to seesuch as pumps and turbines. Thermal done. energyisenergy associated with molecules. Chemical energy is energy that arises from the WORK forces which bindthe *atoms togetherina molecule. Chemical energy is released whenever The turbines and other Power e pment combustion or any other chemical reaction takes used aboard ship are important because they do place. Electrical energy, light waves, and radio work. Work is defined as the result of force waves are examples of energy that are associated Toying through distance. The unit of ineasure withparticlessmallerthanatoms.Nuclear for work is the FOOT-POUND (ft -lb). The two energy is obtained by splitting the atoms. Each parts of this unit are the, POUND OF _FORCE of these types of energy (mechanical, thermal, and the FOOT OF DISTANCE. etc.) must also be classified as either (1) stored Force ismeasuredin pounds.The energy, or (2) energy in transition. -2 4gravitational pull on an object weighing I pound 18 Chapter 3ENGINEERINGFUNDAMENTALS is a force. of 1 pound. If you lift a 1-pound a weight of 100 pounds at the rate of 250 weight from ground level toa height of 1 foot, ft-lb- you exert a force of 1 pound per/second, the machine is exertingonly 0.454, thrOugh a distance horsepower (250 ft-lb 4. 550 ft-lb= 0.454 ltp). of 1 foot, and you have done 1foot-pound of work in the process...A force of100 pounds is If crane hoists 2,000 pounplsof ,cargo to required to raise a 100-pound anvil; ifyou lift it height of 30 feet in 5 seconds,how much to the top of a 30-inch bench, thework you horsepower is developed? Here ishow to get the have done is 2 1/2 ftx 100111= 250 ft-lb. Work answer: (in foot-pounds), thdrefore, equalsthe. force (in pounds) times the distance (in feet). Power =work 2,000 lb X30 ft time 5 sec Now, suppose you want to movea 60-pound anvil across the deck without lifting it, It will =12t000rft-1b per sec take a considerable force toslide,the anvil. If you slide it 10 feet, you do 600 foot-poundsof work. Here the force of 60 pounds Horsepower 12000 ft-lb per sec is required to 550 ft-lb per sec 21.8 overcome the resistingforce of friction between the anvil and the deck. A great deal of the work Orsupposea done by any machine is the Overcoming turbinehas .a known of many horsepower of 37,500 at ratedcapacity, and you frictional forces which resist themotion of the parts. want to know hovt; much work itdoes. You find out by multiplying the developedhorsepower by- the POWER hoursinoperation.Thisgives HORSEPOVVER-HOURS, which isa measure of work for main propulsion machinery, The, ship'smainengines,boilers, main reduction gear, main shaft, andpropellers are frequently called the POWER PLANT;and they LAWS OF GASES are commonly rated according to how much power they can develop. For example, it might The energy transformation of majorinterest take one man 10 hours to load20,000 pounds intheshipboardengineeringplantisthe of ammunition ona truck, whereas a crane transformation from heatto work. To see how could do the. same job in 5 minutes.The amount this transformationoccurs, we need to consider of work done is thesame, but the crane is much thepressure,temperature,anllvolume more powerful than the man. It can do the work relationships which hold ture forgases. In the faster. Power, then relates to workand time; it is middle of the 17th century, RobertBoyle, an the time rate. of doing work. Ifwe assume that Englishscientist,made someinteresting the ammunition is raisedan average height' of 6. discoveries concerning the relationshipbetween feet, the work done is equal to 6 ftx 20,000 lb the pressure, the temperature,antithe volume of or 120,000 ft-lb. Considering theman also as a gasps. In 1787, ,facqties Charles,a. Frenchman, machin6, thepower of each of the two machines proved that all gases ioxpand thesame amount if found by dividing this amount ofwork by the when heated one degred. ifthe pressure is kept time required in each case. Expressing 10hours constant. The 'relationships that thesetwo men in minutes, the man would workat the rate of discovered are summarizedas follows: 120,000 ft-lb- + 600 mil].= 200 ft-lb per min. The computed power of thecrane would be 1. tWhen the temperature isheld constant). 120,000 ft-lb ÷ 5 min..; 24,000 ft-lbper miner an increase in the pressure ona gas causes- 400 ft-lb per sec. proportional decrease involume, A decrease in the prewiire causesa proportional increase in The most common unit ofpower is known volume. asthe HORSEPOWER. Onehorsepower is equivalent to 550 ft-lbper second, or 33,000 2. When the pressure is held ft-lb per ,minute. Thus, if constant, an a lifting machine miles increase in the temperature 'ofa gas, causes\a
19 RENIAN prdtortional increase in volume. A decrease in, Gage Presiuri the 'temperature, causes a proportional decrease in volumik, '-'1 Gage pressure IS the pressure actually shown on the dial of a gage w14ich registers pressures at ' 3. When the volume is held constant, an or above_ atmospheric pressure, Gage pr, ssure is>. increase in the ,temperature of a gas causes actually shown in 'pounds Ilbr scittare inc(psi); proportional incre.aselin pressure. A -decrease n,1 but it may be shown jn ,inches Pof water, the temperature causes a proportional decree mercury, or other lig*, A reading of 1 inch oft- in pressure. water means that the exerted preiltire is able to support a _column of,w1ter l'inclk high, or that. a Suppose we have a boiler in which steam has ,column -*water in a Ultube will be displaced just begun to form. With the steam stop valves inch by the pressure being mdasured. Similarly, a still closed, the Irolume of the steam remains gage pressure reading of 12 inches of mercury constant while the pressure and thetemperature means that the measuredpressUre is atqe to are both increasing. When operating pressure is support a column of mercury 12 inches bth. reached and the steam stop valves are op-ined, Gages are calibrated in inches of water when the high pressure of the steam causes the steam they are to be used for measuring very low.. to flow to the turbines. The pressure `61 pressures. Inches of mercury may be used when steam thus provides the Rprential for do therange of pressures to be measured is work; the. actual conversion of heat to wo IS soewhathigher,sincemercuryis done in the turbines. O approximately14 times heavier than water. Note that a gage pressure reading of zero PRESSURE AND VACUUM means that the pressure being measured is exactly the same as the existing atmospheric Because pressure is very' imRortant to the" pressure. A gage reading of 50 psi means that the engineeringplant, necessirythat you pressure being measured is 50 psi IN EXCESS therela*nshipsbetween gage understand OF the existing atmoserie ptesss0 ure. pressure,atmospheric pressure, vacuum, and absolutepressure.These ' relationshipsare 7 indicated in figure 3-1. Atmospheric Pressure
pressure,'orthepressu e A 11.1.).WHMG HRE5St1RE- AhriOspheric exerted ibythe weight of the air t 14.7 PSI ABSOLUTE, OR 30 INCHES OF MERCURY ABSOLUTE. atmosphere, is. Measured with a EAROMETE OR ZERO GAGE PRESSURE, OR ZERO VACUUM (fig. 3-2), A bar9meter is sirriilar td a manornete - s (see chapter 9), excetit that the indicating tube 45. . is sealed at the top, A:barometer may be made by filling a tube' with mercury And then inverting it 'so at the open, end rests in "a container of tiler which is open to 'the atmosphere. absense ofpressure at the closed end of tie tube permits atmospheric pressure, acting upon the surface of the mercury in the oDen container, to, hold the mercury in the tube at a height which 30 INCHES OF MERCURY corregponds to the pressure being exerted. PSI OR INCHES OF MERCURY'. Normally, at sea level atmospheric...pressure will hold the colunln df mercury at a ,hefght of
0 1318 approximitOpyy 30ches. Since a ,column of Figure 3,tRelaticinships between vacuum, gage mercury 1 itibh high exerts a pressure -of 0.49 pressure, absolute'pressure, and atmosphericpressurkI pounds per square inch a 30-inch column of O , \t, I
el Chapter3ENGINEERING FUNDAMENTALS
pressure; in order1to make prigise measurements of gage pressure or vacuum. 32 HEIGHT OF 31 MERCURY 30 Vacuum COLUMN IS 29 READ HERE A spac-e in which. the 28 pressure is less than atmospheric pressures said to be undervacuum. The amount of vact Wn is expressedin terms of the difference between thepressure in the space and the existing "atmosphericpressure. Vacuum is measured iinches of mercurythat is, t11r., number of. inchq a column of mercury in a tube will be displaced bya pressure equal to the .difference between thepressurein the v cuum space andthe.,, existing atmospheric ressure.
Vacuum gage scales are marked from0 to t. 30. When a vacuum gage.reads,zero, the pressure inthespaceis ATMOSPHERIC the same as theexisting PRESSURE atmospheric jireatirecor, in otherwords, there FORCES COLUMN is no vAtutTh. A vacuumgage reading of 30 OF MERCURY inches of mercury indicatesa nearly perfect UP INTO TUBE vacuum. In actual practice, it is impossibleto obtainaperfect vacuum; and thehighest vacuum gage readings are seldom over 29 inches of mercury.
Absolute Pressure
Absolute pressureis atmospheric pressure 69.86 plus gagepressure, figure 3-2.Operating prinCiple of mercurial or atmospheric pressure barometer. minus vacuum. For example, ifgage pressure is 300 psi, absolute pressure is 314.7psi; or if the measured vacuum is10 inches of mercury, mercury exerts a pressure which is equal to (30. absolute pressure is approximately \20 inches of x 0.49) 14.7 pounds per square inch. Thus,we mercury.Itis can say that atmospheric pressure (zero important to note ..that\ the gage amount of pressure in a space undervacuum can pressurg) at sea level is 14.7 psi,or 14.7 pounds be expressed only in terms of absolute per square inch absolute(psia) Notice, however, pressure. that 14.7 psi is the STANDARkfor atmospheric Sometimes itisnecessary to converta pressure. Since fluctuations from this standard reading from inches of areshownonthe mercury to pounds per barometer,theterm squareinch. figure3-1gives you all BAROMETRIC PRESSURE is used to describe the information you need to make thisconversion. the atmoshperic pressurewhich exists at any Since atmospheric given moment. As a rule, pressure is equal to 14.7 psi you can use the term of to 30 inches of mercury, it iseasy to see that ATMOSPHERIC PRESSURE and the value 14.7. inch of mercury is equal to (14.7 psi psi in place of the actual barometric i- 30) pressure; 0.49. Now convert yourgage reading to absolute butthere may be times when itwillbe pressure(in important to know the actual inchesof mercury)s and then (barometric) multiply this figure by 0.49 psi. FOrex mple to
21 27 1?, FIREMAN convert a vacuum gage reading of 14 inches, of weighs 0.433, pounds, you subtract 0.433 psi mercury to psi, you _would proceed as follops: from the gage reading for each fobt of drop. (CAUTION: Theweight of eachliquidis 1.Convert 14 inches of mercury vacuum to different,id must be determined before you absolutepressure.Absolutepressure is can makeis correction.) atmospheric pressure minus vacuum (30 inches - 14 inches = 16 inches). For example, to correct a pressure gage reading for a pressure head of water, assume that 2.Multiply the absolute ,pressure in inches connected 10 feet below irith of mercury is a steam pressure gage is of mercury by 0.49. Since 1 the steam line. The steam cools and condenses in equal to 0.49 psi, 16 inches of mercury is equal the gage connection line, filling the connection to16 x 0.49 psi) 7.8 psi (approximately 8 psi). line with water. The uncorrected gage reading is ember thatthis answerisin terms of 250 psi. Multiply, 0.433 psi by 10, and then lute pressure. fir subtract the resulting figure from 250 psi: As you can see, it is also easy to convert psi ( 1 )0.433 psi x 10 = 4.33 psi. to inchesofmercury.Sinceatmospheric pressure is equal to 14.7 psi or to 30 inches of (2) 250 psi - 4.33 psi = 245.67 psi. mercury, 1psi is equal to (30 inches of mercury ÷ 14.7) 2.04 inches of mercury. For example, 10 Thus the true pressure in the steam line is psi absolute is equal to (10 x 2.04 inches of 245.67; or approximately 246 psi. mercury) 20.4 inches of mercury absolute. It is sometimes necessary to connect a water Inordertointerpretthe reading, on a pressure gage at some distance above the point pressure gage, you must know the location of at which the pressure is being measured; then the gage in relation to the line in which the the_reading on the gage will show the pressure pressure is being measured. As a general rule, being measured minus the pressure required to pressure gage connections are led from the top support We column of water up to the gage. To of the pressure line. Ckcasionally, however, it is correct the reading you must add the weight of necessaryto locate a pressure gage at some the column of waterthat is, yotr must add distance below the pipe; then the reading on the 0.433 psi to the gage reading for eabh foot of gage will indicate the pressure being measured rise. a plus thpressure exerted by the.weight of the For example, assume that a water pressure column of liquid above the gage. The required gageis connected 5feet above the point at correction should be made in calibration of the which the pressure is being measured. The gage gage. If the correction has not been made in reading is 30 psi. To obtain the actual pressure calibration,itmust bemadein the at the point of measurement, you must add (5 x interpretation of the gage reading. 0.433 psi) 2.17 psi to the gage reading. Thus the Correction fO'r a head of liquid should be actual pressure is 32.17 psi. made as follows: PRINCIPLES OF HYDRAULICS 1.Measure the vertical distance from the center of the gage to the line in which the pressure is being, measured. The word hydraulicsisderived from the Greek word for water (hyd6r) plus the Greek 2.For each foot of the distance measured, word for a reed instrument like an oboe (autos). subtract from themgage reading the weight of a The term "hydraulics" originally covered the column of liquid l'foot high and ;,.1 inch square study of the physical behavior of water at rest in cross section. If you are measuring pressure andinmotion.However, themeaning of on a steemfor-wffter line, you must correct for a hydraulics has been broadened to covet the pressure head of water. Since a column of water physical behavior of all liquids, including the oils 1 foot high and 1inch square in cross section that are used in present day hydraulic systems.
22 28 (;#
Chapter 3ENGINEERINGFUNDAMENTALS
FORCE 1e 100 LBS. FORCE 2 = 100 LBS.
/
5.181 Figura 3-3.Principlo of mochapicol hydraulics.
During the period before World War I, the in every direction. Water will leave Navy began to apply hydraulics extensively the hose at to the same velocity, through leaks, regardlessof navalmechanisms.Sincethattime,naval where the leaks are in the hose. applications have increased to theextent that many ingenious hydraulic devices are used in the Let us now consider the effect of Pascal's solution of problems of gunnery, navigation,and law in 'the system shown in figure3-3. If the aeronautics. Aboard s ip today the applications force at piston A is 100 pouridsand the area of of hydraulics includea chor windlasses, power the piston is 10 square inches, thenthe pressure cranes, steering gear,r mote controls, power in the liquid must be 10 poundsper square inch drives for the elevation guns and training of (psi). This pressure is transmitted to pistonBso mounts andturrets,po der andprojectile that for every square inch of itsarea, piston B hoists, recoil systems, gunrammers, and airplane willbe pushed upward witha force of 10 catapults. pounds:-Inthisexamplewearemerely consideringaliquid column of equalcross The foundation for modern hydraulics began section so that the areas of the pistons\are equal. in 1653 when Pascal discovered that "pressure All we have done is tocarry a 100-pound force set up in a liquid acts equally in all directions." around a bend; however, the principle illustrated Thispressureacts at eightanglestothe is thebasisforpracticallyallmechanical containing surfaces. hydraulics. When we apply a force to the end ofa The same principle may be applied columnof where confinedliquid,theforce is the input piston is much smaller thanthe output transmitted not only straight throughto the pigton or vice versa. Assume that thearea of the other end, but also equally inevery direction input piston is 2 square inches andthe area of throughout the columnforward, backward, and the output piston is 20square inches. If you sidewayssothatthecontainingvesselis apply a pressure of 20 poundsto the smaller literally filled with pressure. This is thereason that a piston, the pressure created in the liquid will flatfirehose takes on a circularcross again be I0 pounds persquare inch because the section whenitiS filledwith water under forceis concentrated on a smallerarea. The pressure. The outward push of the water is equal upwatd force on the larger piston will be 200
23 29 FIREMAN
pounds 10 pods for each of its 20 square they are no the same. Water from a water main inches. Thus yocan see that iftwo pistons are feels cool untilit has been over a fire a few used in a hydraulic system, the Torce acting on minutes. Itevidentlymusthavereceived each piston will be directly prOportional to its something (fromthefire.If you place two area, and the magnitude of each force will be the pennies together, one of which was heated by product of thepressure and the area of the being held in the flame of a match, in a short piston. time the tWo pennies will be equally warm. Again, something passed into the cooler object PRINCIPLES OF PNEUMATICS and made it hot. That something is called heat. Pneumatics is that branch of Mechanics that Many formsofmechanicalactionalso' deals with the mechanical properties of gases. produce considerable quantities of heat. For Perhaps the most common application of these example, you rub your hands together to warm properties, used in the Navy today, is the use of them when they are cold. Matches are ignited by compressedair.Compressedairisused to rubbing them on a rough surface. A Hull transmit pressure,accordingto Pascal's Maintenance Technician can notice heat in a principle,in a varietyof applications.For piece of metal after hammering it; and the head example,intiresand air-cushionedsprings, of a nail is heated when the nail is driven into compressed airacts as" a .cushion to absorb wood. shock. Air brakes on locomotives an large truckscontributegreatlytothesafetyof The molecules in the nail (as in all matter) railroad and truck transportation. In the Navy, are in continual motion. The blow on the nail compressed air is used in numerous ways. For increases the molecular motion. late molecules example, tools such as riveting hammers and in the top layer receive the impulse from the pneumaticdrills are air ozerated. Automatic hammer and vibrate with greater violence. The combustion control systemslitilize compressed increasedvibration and energy of motion is piairfortheoperationoftheinstruments. passed on\ to layer after layer of molecules. Compressed air is also used in diving bells and Thus, the effect produced by the blow is a diving suits. Perhaps a brief discussion on the use general increase in the motion ofthemolecules. of compressed air as an aid in the control of This energy of molecular motion is called heat. submarineswillbest explainthetheory of pneumatics. Because molecules are constantly in motion, Submarines are designed with a number of they exert a pressure on the walls of the pipe, tanks that may be used for the control of the boiler, cylinder, or other object in which they ship. These tanks are flooded with water to are contained. Also, the temperature of any submerge; or they are filled with compressed air substancearisesfrom and is directly to surface. proportional to the activity of the\ molecules. The compressedairforthepneumatic Therefore, every time you read theh'nometers and pressure gages you are findingout systemismaintained in storage tanks (called something about the amount of internal energy banks)at a pressure. of 4,500psi.During surfacing the pneumatic system delivers contained in the substance. !High pressures and compreSsed airto the desired control tanks. temperatures indicate that the molecules are Since the pressure of the air is greater than the moving rapidly and that the substance therefore pressure of the water, the Water is forced out of has,a lot of internal energy. the tank. As a result, the weight of the ship Heat is a more familiar term that internal decreases; it becomes more buoyant, and thus energy!, yet one that may actually be more tends to rise to the surface. difficultto definecorrectly. The important thing to remember is that HEAT IS THERMAL HEAT ENERGY IN TRANSITIONthatis, itis You undoubtedly know from experience theimalenergythatismovingfromone that heat and temperatifit are related; however, substance orsystem to another.
24 30 Chapter 3ENGINEERINGFUNDAMENTALS
An examplewillhelptobillustrate the substance to another is normallyreflected in a difference between heat and internalenergy. temperature change Suppose there are two equal lengths ineach substancethe of pipe, hotter substance becomes cooler,the cooler made of identical materials andcontaining steam substance bedomes hotter. However,the flow of at the same pressure andtemperature. One pipe heat is not reflected in iS well insulated, the other is a temperature change In a not insulated at all. substance which is in theprocess of chatigink.,. From everyday experienceyou know that more heat will flow from the uninsulated from one physical state (solid,liquid, or gas) to pipe thari another. When the flow of heat is from the insulated pipe. Whenthe two pipes are reflected in a first filled with steam, the temperature change, wesay that SENSIBLE steam in one pipe HEAT has been addedto or removed from the- contains exactly as much internal energyas the steam in the- other pipe. We know this substance. When the flow of heat isnot reflected is true in a temperature change bntis reflected in the because the two pipes contain equalvolumes of changing physical state of steam at the same pressure andat the same a substance, we say that LATENT HEAThasbeenaddedor temperature. After a few minutes, thesteam in removed. theuninsulated pipe will contain much less Does anything botheryou inthis internal energy than the steam inthe insulated last ipe, as we can tell by measuring paragraph? It should. Herewe are talking about the pressure sensible heat and Tatcn$ heatas though we had nd the temperature of thesteam in each pipe. two different kinds of heat hathashappened? to consider. As Storedthermal noted before, thisis common (if inaccurate) energyinternal energyha Toyedfrom one engineering language. So keep place to another, first from thesteam to the the following pipe, then from the uninsulated pipe points clearly in mind: (1) `heatis the flow Of to the air. thirmal energy; (2) whenwe talk about adding The MOVEMENT or FLOW of thermalenergy is and removing -heat, what should be called heat. we mean that we are providingtemperaturedifferentialssothat thermal energy can flow f ?omone substance to Units of Measurement another; and (3) whenwe talk about sensible heat and latent heat,we are talking about two Both internal energy and heat are"usually differentkindsof EFFECTS thatcan be measured using the unit calledthe B ITISH produced by heat, but not abouttwo different THERMAL UNIT. (Btu). Formost pcticif? kinds of heat. engineering purposes, I Btu is defined as the The three basic physical states ofall matter amountof,-thermal energy required to raisethe are SOLID, LIQUID, and GAS (orvapor). The' temperature of I pound of water 1 °F. physical state of a substance isclosely related to the distance between molecules. When large amounts of thermal As a general energy are rule, the moleculesare closest together in solids, involved, itis usually more convenientto use farther apart in liquids, and multiples of the Btu. For example.. farthest apart in 1 kBtu is gases. When the flow of heat toa- substance is equal to '1,000 Btu, and' Imint], is eqifial to not reflected in a temperature 1,000,000 Btu. change, we know that the energy is being usedto increase the Another unit in which thermalenergy may distance between the moleculesof the substance e measured is the CALORIE, the amount of and thus to change it froma solid to a liquid or eat required to raise the temperature of1 gram from liquid to agas. You might say that latent of water 1° C. One Btu equals 252calories. heat is the energy price thatmust be paid for a change of state from solidto liquid or from liquid to gas. The Sensible Heat and Latent Heat energy is not lost; rather, it is stored in the substanceas internal energy. The energy price is repaid, so to speak, Sensible heat and latent heat when the are terms often substance changes back from'gas .to liquid or used to indicate the effect thatthe flow of heat from liquid to solid, since has on a substance. The flow of heat flows from the heat from one substance during these changes ofstate. 25 31 FIREMAN
LATENT HEAT LATENT OF VAPORIZATIAN SENSIBLE SENSIBLEHEAT,OF SENSIBLE (OR LATENT HEAT \ HEAT FUSION HEAT OF CONDENSATION) HEAT 300°
SUPERHEATINGy /1\ WATER BOILING 212° doo-- 200° STEAM CONDENSING STEAM COOLING '
100°
ICE WARMING ICE I MELTING 32° ICE WATER COOLING FREEZING 0 16 144. 180, 7 970 44 BTU PER POUND OFWATER
38.1 Figure3.4. Relationship between sensible heat and Talent heat for water atatmoshperic pressure.
Figure 3-4 shows the relationship between change in temperature while the ice ,is melting. sensible heat and latent heat for one surance, Afterallthe ice has melted, however, the water, at atmospheric pressure. (ThV'same kind temperature of the water will be raised as of chart could be drawn for other substances; additional heatissupplied. If we add 180 however, different amounts of thermal energy Btu ti. atis, 1 Btufoteachdegreeof would be involved in the changes of state.) temperature between 32° F and 212° Fthe If we start with 1 pound of ice at 0° F, we temperature of the water will be raised to the must add 16 Btu to rasie the temperatureof the boiling point. To change the pound of 'water at ice to 32° F. We call this adding sensible heat. 242° F t9 a pound of steam at 212° p, we must To change the pound of ice at 32° F to a pound add970Btu(the LATENT HEAT OF of water at 32° F, we must add 144 Btu (the VAPORIZATION). After all the water has been LATENT HEAT OF FUSION). There will be no converted to steam the addition of more heat 32, 26 Chapter 3 ENGINEERINGFUNDAMENTALS
will cause an increase in the temperattrre of the In the CELSIUS SCALE, the ''steam.41f we add about44 Btu to the pound of freezing point of 'pure water is 0° andthe boiling point of pure steam which is at 212° F,we can superheat it to 300° F. water is 100°. Therefore, 0° Cand 100° C are equivalent to 32° F and 212°F, respectively. The same, relationships applywhen heat is Each degree of Celsius is largerthan a degree of being removed,: The removal of44 Btu from the Fahrenheit since thereare only 100° Celsius pound of steam which is at 300°F will cause the betweenthe freezing and boilingp9ints of temperature to drop to 212° F. Asthe pound of water,whilethis same temperature change steam at 212° F changestoa pound of water at requires 180° on the Fahrenheitscale. Therefore 212° F, 970 ctuare given? off. When a substance is changing iThm agas or vapor to, a liquid, we the degree of Celsius is 100or or 1.8° Fahrenheit. usuallyusetheterm LATENT HEAT OF In the Celsius scale absolutezero is -273°. CONDENSATION for the heat thatisgiven off. Figure 3:5 shows the two Notice, temperature scales however,thatthelatentheatof in comparison and alsointroduces the simplest condensation is exactly thesame as the latent heat of vaporization. The removalof another 180 uofsensibleheatwilllower the FAHRENHEIT SCALE CELSIUS SCALE temperature of the pcumd ofwater from 212° F FAHRENHEIT CELSIUS to 32° F. As the pound of TEMPERATURES TEMPERATURES water at 32° F '270A changes to a Pound of ice at 32°F, 144 Btu are 26011 tu)"c given off without any accompanying 25011 change in 24011 120 temperature. Further removal of heat 23011 causes the 110 22011 temperature of the ice to decrease. MATER BOILS OR CONOENSE S 21011 100 _ 200 194- TEMPERATURE ' 19011 - 90 11 17011 BO 16011 70 The temperature ofan object is a measure of 15011 how hot or cold the object is; itcan be measured 140 60' 130 by thermometers and readon their temperature 120 50 scales.. 110 J94 100 40 The temperature scales employed 00 to measure BO 30 " temperature are the Fahrenheit Kali: 70 and the 20 Celsius (centigrade) scale. In 60 -engine..ring and for 50 I0 practicallyallpurposesintheNavy,the 40 30 32.....4CE MELTS -WATER FREEZES 0 Fahrenheit scale is used. It 20 may, however, be .214. necessary for you to convert Celsius readings 10 10 to 0 theFahrenheitscale,sobothscalesare -10 -20 explained here. -20 -30 -30 The FAHRENHEIT SCALE hastwo main -40 -40 reference pointsthe boilingpoint of pure water MERCURY at 212°, and the freezing point ofpure water at 32°. The size of a degree ofFahrenheit is 1/180 MELTING ICE of the total temierature changefrom 32 to BOILING WATER - 212°. And the scalecan be extended in either directionto higher temperatures withoutany limits, and to lower temperatures(by using ,A MINUS degrees)down'tothelowest temperature theoretically possible, the absolute zero. This temperature is -460°, (31'492° below the freezing point of water. 3311 Figure 3-5.Temperature scales. 27 33 FIREMAN .
^ of the temperature measuring instruments, the carbondioxide,nitrogen,water vapor, and liquid-in-glassthermometer.' Thetwo sulphur 'dioxide. The oxygen required to burn thermometers shown are exactly alike in size the- fuelisobtained from the air. Air isa ap* shape; tl-tb only difference is the outside mechanical mixture containing by weight 21 maitings,,,,or scales on them. Each thermometer percent oxygen, 78 percent "nitrogen, and I is a hollow glass tube which has a mercury-filled' percent other gases. Only oxygen is used in bulb at the bottom, and which is sialed at the combustion of the fuel;nitrogefi is an inert gas top. Mercury, like any liquid, expandswhen whichhasnochemicaleffectuponthe heated and will rise in the hollow tube. The .cotnbustion. illustration shows the Fahrenheit thermometer The chemical combination obtained during with its bulb standing in ice water (32° F), while combustion resultsinthe libeption of heat the 'Celsiusthermometerisinboiling water energy, a portion of which is, used topropel the ( 1 00° C). ship. Actually, what happens is a rearrangement The essential point to remember is that the of the atoms of the chemical elements into new level of the mercury in a thermometer depends combinations of molecules. In other words, as only on the temperature to which the bulb is the Semperature of the fuet, oil in the presenceof exposed.Ifyouweretoexchangethe oxygen is increased to the ignition point, the.' thermometers,themercuryintheCelsius. various chemical elements in the fuel begin to thermometer would drop to the level at which separate from each other and to unite with themercury now stands inthe Fahrenheit certain amounts of oxygen to form entirely.iiew thermometer,while themercury ' inthe .substances, which give off heat energy in the Fghrenheit thermometer would rise to the level process. A mod fuel has ahigh' speed of af which tilt mercury now stands in the Celsius combustion, thus producing a large amount of thermometer. The temperatures would be 0° C heat in a short time. for the ice water and. 212° F for the boiling water. PERFECT COMBUSTION is the objective. If you place both thermometers in water However, this cannot be achieved as yet in either containinglumpsofice,theFahrenheit a boiler-orthecylindersofan thermometerwill read 32° and the Celsius internal-combustion engine. Theoretically, itis thermometerwillread0°.Heatthe water simple. It consists of bringing each particle of slowly. The temperature will not change until the fuel (heated to its ignition temperature) into the ice in the water has completely melted (a .contact with the correct amount of oxyvn. The great deal of heat is required just to melt the following factors arc involved: ice), then both mercury columns will beginCo rise. When the mercury level is at the+10° mark I. Sufficient air must be supplied. on the Celsius thermometer,itwill be at the +50° mark on the Fahrenheit thermometer. The 2., Theair andflIelparticlesmust be two columns will rise together at the samespeed thoroughly mixed. and, when the water finally boils, they will stand at 100° C and 212° F, respectively. The same 3.Temperatures must be high enough to temperature changethat is, the same amountof maintain combustion. heat transferred to the waterhas raised the temperature 100° Celsius and 180° Fahrenheit, 4.Enough time must be allowed to permit but the actual change in heat energy isexactly completion of the process. the same. However, COMPLETE COMBUSTION can COMBUSTION be achieved. This is accomplished by supplying, more oxygen to the process than-would be The term "combustion" refers to therapid requiredif perfect combustion were possible. .10.mical union of oxygen with a fuel. The The resultis that some of the excess oxygen perfect cbmbustion of fuel should result in appears in the combustion gases.
28. 34 C)
!) Chapter 3ENGINEERING FUNDAMENTALS
STEAM The physical properties. qa some metalsor metal alloys make them more. suitable forone Stearn is water to which enough heat has use than for another. Various terms are used in been added to convert it from the liquid to the describing the physcial properties of metals. By gaseous state. When heat is added to water in an studying the following. explanations of these open container, steam forms, butit quickly terms you should have a better understanding of mixes with air and cools back to water which is why certain metals are used on one part of the dispersed in the air, making the air more humid. ship's structure and not on another part. If you add the heat to waterina closed container, the steam builds up pressure. Ifyou STRENGTH refers to the ability of a metal add exactly enough heat to convert all the water to maintain heavy loads (or force) without to steam at the temperature of boiling water, breaking. Steel, for example, is strong, but lead you get saturated steam. SATURATED STEAM is weak. is steam saturated with all the heat it can hold at HARDN SS refers to the ability ofa metal the boiling temperature of water. to resist pene ation, wear, or cutting action; The boiling temperature of water becomes higher aslhe pressure over the water becomes .MALLEABILITY isa property of a metal higher, 'Steamhotterthantheboiling that allows it to be rolled, forged, hammered,or temperature of water is called SUPERHEATED shaped, without cracking or breaking. Copper is STEAM. When "steam has 250° of superheat, a very malleable metal. theactual. temperature is theboiling BRITTLENESS is a property of a metal that temperature plus 250° F. At 600 psi the boiling will alldw it to shatter easily. Metals suchas cast temperature of water is 489° F. So if steam at iron or cast aluminum, andsome very hard steels 600 psi has 250° F of superheat, its actual are brittle. temperature is 739° F. WET STEAM is steam at theboiling temperature which stillcontains DUCTILITY refers to the ability of a metal ," somewaterparticles-. DESUPERHEATED to stretch or bend without breaking. Soft iron, STEAM is steam which has been cooled by being soft steel, and copper are ductile metals. passed- through a pipe extending through the TOUGHNESS Is the property of a metal that steam drum; in the process the steam loses all will not permit it to tear or shear (cut) easily butapproximately20°For30°F ofits and that allows it to stretch without breaking. superheat.Theadvantageof desuperheated steam is that it is certain to be dry, yetnot so Metalpreservationaboardshipisa hot as to require special alloy steels forthe continuousoperationsincethemetalsare constructionofthepiping thatcarriesthe constantly exposed to fumes, water, acids, and desuperheated steam about the ship. moist salt air; all of these will eventuallycause t.- corrosion. The corrosion of iron and steelis called rusting and results in the formation of METALS iron oxide (iron and oxygen) on the surface of the metal. Iron oxide (or rust) can be identified As you look around, you see that not only is easily by its reddish color. (A blackishhue your ship constructed of metal, but also that the occurs in the first stage of rusting but is seldom boilers, piping system, machinery, and even your thought of as rust.) Corrosion can be reduced .or bunk and locker are constructed of some type of prevented by using better grades of base metals: metal. No one type of metal can serve all the by adding special metals such as nickel and needs abbard -ship. Many types of metals or chromium, or by coating the surface with paint metal alloys must be used. A strong metal must or other metal preservatives. be used for some parts of a ship, while a Metal and alloys are divided into two general lightweight metal ais needed for other parts. classes: ferrous and nonferrous. Ferrous metals Some areas require spedial metal that can be are those that -are composed primarily of iron. shaped or workeslyeg easily. Nonferrous metals are those that are composed
29 35 FIREMAN
p arily of some element or elements other These systems have been so designed that ven th iron. One way to tell a common fen;ous after a portion of the metal has been reoved metal from a nonferrous metal, is by using a the identifying marks are still visible.. magnet; most ferrous metal is magnetic and In the continuous identification . marking nonferrous metal is nonmagnetic. system, the identifying information is actually Elenientsmustbi alloyed ,r (ormixed) painted on the metal with a heavy ink. This togethertoobtainthedesiredphysical marking appears at specified intervals over the properties of a metal. For example, alloying (or length of the metal..The marking contains the mixing)chromiumandnickelwithiron prOducer'strademarkandthecommercial produces a metal known as special treated steel. designation of the metal. The marking also Special treated steel (STS) has great resistance to indicates the physical condition of the metal penetrating and shearing forces and is used for such as `;fold drawn," "cold rolled," "seamless," gun Adds, turrets, protective decks, and other and others. vital areas. A nonferrous alloy that has many In the color markingsy4em,a series of color uses aboarAhnip is copper-nickel, which is used symbols with a related color code is used to extensivel salt/ waterpipingsystems. identify metals. "Color symbol" refers to a color Copper-nickel is produced by mixing copper and marking actually painted on the metal. The nickel together. There are many other different symbol is composed of one, two, or three colors metals and alloys used aboard ship which will and is painted on the metal in a conspicuous not be discussed here. place. These color symbols correspond to the WitIVall the different types of sed elements of which the metal is composed. aboard ship, so/ne way must be used to ide tify For further information on the metals used these metals in the storeroom. At the p sent aboard ship, their properties and identification ,time,theNavyutilizestwosyitem of systems, refer to the Rate Training Manual, Hull v identifying, metals: the continuous identifica Maintenance Technician 3 & 2, NAVEDTRA marking system and the color marking systein. 10573.
O
36 CHAPTER 4 SHIP P PULSION / The primary, function Of any marine mechanical energy required to turn the propeller engineering plant is to convert the chemical is provided by the turbines. Reductionsears are energy off' a fuel into useful work and to utilize used on practically all Asteam-dOwn ships tb 4. that work in the propulsion of the ship. A connect the turbine to the shaft in a manner propulsion unit consists of the machinery and that allows the turbines to operate at high equipment, including their controls, whichare rotational speeds while the propeller operate at mechanically, electrically, or hydraulically lower rotational speeds, thus allowing Most connected to a propulsion shaft. efficient operation of both turbines and propellers. This chapter contains information on the principles of ship, propulsion Sand, in addition, The general principle of ship propulsion is acquaints you with some of the different types illustrated in figure. 4-1. of ship propulsiOn units, which include the O geared-turbine drive, the turboelectric drive, diesel electric drive and the:straight diesel.Angine TYPICAL drive. PROPULSION UNITS Propulsion units with various types and PRINCIPLES OF designs of prime movers are currently inuse in SHIP PROPULSION naval ships. The prime movers of a propulsion unit may be either a geared turbine a turbine A ship is propelled through the Water by and a generator, a diesel engine anda generator, means of some device which imparts velocity to or a straight diesel engine. These are the most a column of water and moves it in the direction common types of prime` movers of propulsion opposite the direction in which it is desired to units with which we are most concerned. move the ship. A reactive force (thrust)is thereby developed against the velocity-imparting GEARED-TURBINE DRIVE device, and this thrust, when transmitted to the ship, causes the ship to move through the water. In the geared-turbine drive, the unit parts or All propelling devicesoars, paddle wheels, and sections that make up the individual propulsion propellersare designed to move a column of units consist of the main turbines and the water in order to build up a reactive force reduction gear. sufficient to move the ship. Figure 4-2 shows the general arrangement of The screw-type propeller is the propulsion the turbines and gears in a geared-turbine device used in practically all naval ships. The propulsion unit. Not all geared-turbine plants. thrust developed on the propeller is transmitted have the cruising turb,me which is included in to the ship's structure by the *shaft through the the diagram. Ordinarily(, cruising turbines will be thrust bearing. On most steam-driven ships, the found in only the older destroyers.
31 37 01IkFIREMAN
THRUST r STRUT ( BEARING
HAIN SPRING .
SHAFT BEARINGS.
.4. MATER COLUMN
- STRUT ING STERN TUBE PROPELLE BEARING
DIRECTION OF HULL REACTIVE FORCE (THRUST)
47.42 Figure 4-1.General principle of ship propulsion.
In a- typical destroyer propulsion plant, the turbine will be revolving at 2,880 rpm (1.8 X 16 speed reduction ratio between the cruising X 100), the high pressure turbine at 1,600 rpm turbine shaft' and high pressure turbine shaft is (16 X 100), and the low pressure turbine at approximately 1.8 to 1. The speed jittio between 1.,300 rpm (13 X 100). the high pressure turbine shaftd propeller Figure 4-2 shows two astern elements, one at shaft is 16 to 1, and the ratio between the low each end of the low pressure turbine. This pressure turbine and propeller shaft is 13 to 1. arrangement is typical for combatant type ships; In other words, in operation, if the propeller auxiliary type ships,%usually have one astern shaft is revolving at 100 rpm, the cruising element instead of two, and that one invariably
ASTERN ELEMENT
1' I LOW-PRESSURE I TURBINE
MAIN CRUISING REDUCTION TURBINE GEARS REDUCTION GEAR
MAIN SHAFT HIGH - PRESS E TURB
CRUISING TURBINE
47.1 Figure 4-2.Geared-turbine propulsion unit.
32 Chapter P, PULSION is located at the forward end of the lowpressure TUTt.BOELECTRIC DRIVE turbine (the end\ farthest from the reduction gear). urboelectric drive installations havea single The propulsion shaft, which extends from turbine unit for each installed shaft.Figure 4-1 ain gear (lovi\speed) shaft of the reduction shows the diagrammatic arrangement of gear to a ropellCr, is supported and held, in turboelectric propulsion unit.: *you cansee, alignment at the spring bearings, the stern tube the propuldtin unit includesa turbine, main bearings, and strut bearing. The axial thrust, generator, propulsion motor, and a propulsion- acting, on She propulsion shaft as a result of the control board, a direct current generator for pushing effect of the propeller, is absorbed in supplying rotor field current to the proptilsion th't main. thrust bearing. ,In mostships, the main motor and excitation current to the generator. thrust bearing is located 'at the forward end of Figure 4-4 is an illustration ofa tYpiC11 control the main shaft, within the reductiongear casing. board. In some very large shipa however, the main The speed reduction ratio between turbine shaft thrust bearing is located farther aft ina and propeller in the turboelectric drive is, machinery space or a shaft alley. approximately the same as in the geared-turbinel
TURBINE SPEED le LEVER SPEED- (AUTOMATIC CONTROL) GOVERNING VALVES -COMBINED FIELD
REVERSING - LEVER EMERGENCY S)3EED LEVER MANUAL CONTROL.)
"I NILam, STATOR
...... ,11 1 "1" -----r- DIRECT- ;FIELD CURRENT TURBINE i-i--4-' GENERATOR :0 ,___
DRIVER MAIN PROPULSION GENERATOR MOT R GENERATOR-FIELD MAIN CONDENSE CONTACTORS
47.2 Figure 4-3.-Diagram of the turboelectric drive. 1. PHASE BALANCE RELAYS 19. INDICATING LAMP HEATER 2. GROUND PROTECTIVE RELAY 20. EXCITER VOLTMETER,AND GROUND DETECTOR 04ITCH 3. NAMEPLATE,FOR GEN FIELD AMP 21, CONTROL SWITCH , 4. EXCITATION SET STARTING SWITCH 2Z, MOTOR-STATOR TEMPERATURE INDICATOR SWITCH 5. TEST BLOCK 21 GENERATOR STATOR TEMPERATURE iNdICAtOR SWITCH 6. STANDBY EXCITER CONTROL SWITCH 24. SHAFT RPM INDICATOR AND REVOLUTION COUNTER ENGINE ROOM TELEGRAPH 21 SHAFT RPM INDICATOR AND REVOLUTION-INDICATOR 8. CLOCK 26. RPM TELEGRAPH 9, GENERATOR FIELD AMMETER 27. LOAD LIMIT CONTROL, RELEASE 10. TURBIN, SPEED INDICATOR 28. LOAD LIMIT CONTROL HANDWHEQ. 11. GENERATOR INDICATING WATTMETER 29, EXCITER Fla.!) RHEOSTAT 12. MOTOR FIELD AMMETER 30, MOTOR SET UP LEVER 13. EXCITER AND GROUND DETECTOR VOL TMETEFt 31. FIELD LEVER 14. GENERATOR AMMETER 32. REVERSER LEVO1' 15. GENERATOR VOLTMETER 33. .GOVERNOR CONTROL LEVER, 16. STATOR COIL TEMPERATURE INDICATOR 34. EMERGENCY LEVER '7. INDICATING LAMP CONTROL BUS 35. TURBINE TRIP HANDLE ,\ 18. INDICATING. LAMP WRONG DIRECTION INDICATOR 36. NAMEPLATE FOR EMERGENCY{ OPERATION O f95 Figure 4-4.Propulsion control equipmentDE-51 class.
34 Chapter4SHI USLION
4,
139.10 Figure 45 =Main propulsion diesel engine. drive andisbrought about electrically. For Figure 4-5 shows one of the mein proptlsion example, in one class of turboelectric drive type diesel engines aboardan oceanographic research destroyer escort, the normal operatingrange ship. Figura. 4-6 shows the main prop4Ision fixed speed ratio between the turbine-generator switchboard operating station aboard thesame set and the propulsion motor is 14 to 1. ship.
One of the outstanding differences between Si. The propulsion equipment for a fleet tug geared drive and electric drive is that the latter th4t utilizes diesel electric drive consists of four does not have an astern turbine element. In the diesel-engine driven generators furnishingpower electric drive the direction of rotation of the to one propulsion motor rated at 3,000 propulsion motor, and consequently the horsepower which in turn drives the propeller. propeller, is controlled'bythe electrical switch The four generating units are normally located set . Therefore, thereis no need to reverse amid-shipstwo on the port side and twoon the turbine rotation for astern operatio starbqard side.
DIESEL ELECTRIC DRIVE The control of direction (forward or reverse) and the speed of propeller rotationis accomplished at the control board. A typical Diesel electric drive is best suited to ships in control board installation aboard a fleet tug is the low or mediurn horsepower range up to shown in figure 4-7. O about 6,000 shaft horsepower.Ithas been installed in approximately 175 escort ships and In the propulsion plant's of.some 5 00 surface ships and craft of other types, diesel-driven ships, thereis no mechanical including minesweepers, submarine tenders, connection ,between thkengine(s) and the older submarines. fleet and harbor tugs, fuel oil propeller(s). In such plants, the diesel engines tankers and barges, rescue and salvage craft and are connected directly to generators. The miscellaneous unclassified craft. electricity produced by-such an engine-driven
35 41 sl
FIREMAN
J
139.11
Figure 4-6.main propulsion switchboard, unabated operating station. , generator istransmitted through cables to a the propeller. The electric system is arranged so motor. The motor is connected to the propeller that the flow of current through the motor can shaft directly, or indirectly, through a reduction be reversed. This reversal in the flow of current gear. When a reduction gear is included in a I causes the rocitor to revolveinthe opposite diesel electric dnve, the gear is located between direction. Thus, the direction of rotation of the the motor and the propeller. motor and of the propeller can be controlled by The generator and the motor, of ,a manipulating the electrical controls. electric drive may be of the alternating current (a-c) type or of the direct current (d-c) type. DIESEL ENGINE DRIVE Almost alldiesel electric drives in the Navy, Diesel engine drive is used on various types however, are of the direct current type. Since of auxiliary ships and craft such as the speed ofd-c motor varies directly with the minesweepers, subchasers, ammunition ships, voltage fuAished by the generator, the control patrol craft, landing ships (LST), and numerous system of an electric drive is so arranged that the other yard craft and small boats. You may also generator voltage can be changed at any time. find diesel drive on a few of the older destroyer An increase or decrease in generator voltage is used as a means to control the speed of the escorts. propeller. Changes in generator voltage may be The Navy uses the diesel engines except brought about by electrical means, by changes in where special conditions favor the gasoline engine speed, or bya. combination or these engine. Standardization of fuels, cheaper fuel, methods. The controls of an electric drive 'may and reduction in fire hazards have been the chief be in a location remote from the engine, such as factors in favor of the diesel engine. the pilot house. 4 The diesel engine used in some of the older In a d-c electric drive, a reverse gear cannot" destroyer escorts developed approximately be used to reverse the direction of rotation of 6,000 hp. The diesel engines of minesweepers
36 42 Chapter - 4SHIP PROPULSION
ENGINE MS r M2 M315MI R 5 MI M2 M9 1.15 MI M4 MO M7 ORDER TELEGRAM
"11 SHAFT Dia Rpm INDICATOR 3W$ GW2 SW1 III SW4 r =1 RH1 L,----t CZ:3 WO WRONG 0 q DIRECTION SW11 swn .SW1I INDICATOR .
CONTROLLER . pi
Sw SW10 SW10 SW 11112 EMERGENCY STOP RELEASE
GENERATOR GENERATOR MOTOR PANEL PANEL PANEL ti
X
MI- GENERATOR VOLTMETER, 500-0-500 M2-EXCITER AND GROUND DETECTOR VOLTMETER, 100-0-100 M 3 - AUXILIARY POWER AMMETER, 0- 2000 M4 -MOTOR AND GROUND DETECTOR VOLTMETER, 1000-0 -1000 MS-ENGINE SPEED INDICATOR, 0-1000 M6 - MOTOR FIELD AMMETER, 0 -ISO M7 MOTOR AMMETER, 3000 -0 -3000 M6 -PILOT HOUSE MOTOR AMMETER, 3000-0-3000 (NOT SHOWN) MO-EXCITATION VOLTMETER (SHIP'S SERVICE), 0-300 SWI -EXCITER VOLTMETER AND GROUND DETECTOR TRANSFER SWITCH SW2-AUXILIARY POWER GENERATOR FIELD CONTROL SWITCH SW3-MDTOR VOLTMETER AND GROUND DETECTOR TRANSFER SWITCH SW4 -EXCITER VOLTMETER AND GENERATOR FIELD GROUND DETECTOR TRANSFER SWITCH SWS-ENGINE SPEED -EXCITER FIELD SWITCH ON GENERATOR SET-UP SWITCH (NOT SHOWN) SW6-ENGINE SPEED CONTROL SWITCH SW7- EXCITATION CONTROL SWITCH SWEI -PILOT HOUSE-ENGINEROOM TRANSFER SWITCH SW9.10-GENERATOR SET-UP SWITCHES SW11 -GENERATOR CONTROL SWITCH RHI -AUXILIARY POWER GENERATOR FIELD RHEOSTAT RH2-MOTOR RELI) RHEOSTAT PI -ENGINERODM CONTROLLER
27.100 Figure 4-7.-Propulsion control oquipment-floot tug. 43
37 FiREIVIAN and subchascrs will develop approximately of the propeller shaft. Youcan see that this 1,800 hp; while some of the enginesin the would take time and bevery hard to do if smaller yzird craft will develop from 190 to 225 sudden changes in direction were required. hp. A typical dieselvengine 'is shown in figure To eliminate this stopping-starting situation 4-8. and to make a smoother transition from forward Sortie diesel engines are directly reversible. to reverse in less time, reverse-reductiongears, This means that the propeller shaft is connected clutches, and hydraulic couplingsare used. directly to the diesel engine, so that the speed of (These are discussed in the following sections of the propeller shaft is controlled by the speed of this chapter.) the diesel engine. When it becomesnecessary to change the direction of rotation of the propeller shaft, the diesel engine must be stopped,the CONVERTING cam shaft of the engine must be shifted for POWER TO DRIVE reverse rotation, and then the engine is restarted. This allows the engine to operate in the opposite The basic characteristics ofa propulsion unit direction; thus reversing the rotational direction make it necessary, in most instances': forthe
SCAVENGING AIR INTAKE EXHAUST LIANIFOLD SILENCER
SCAVENGING AIR BLOWERS
GEAR BOX
PROPELLER DRIVE HUB
REVERSING CLUTCH
SUBBASE
REVERSING CONTROL 44 75.44X Figure 4-8.Typical dieml engine and reductiongear.
38 r
Chapter 4 --SHIP PRPULSION
CRUISING TURBINE
SINGLE REDUCTION 444 LOW PRESSURE GEAR TURBINE
HIGH PRESSURE TURBINE
QUILL SHAFT
1st. REDUCTION -.Tr.--,==.10t. REDUCTION GEAR GEAR t3
2nd. REDUCTION PINION 2nd. REDUCTION GEAR
JACKING MOTORa / GEAR ENCASED-1 MAIN SHAFT COUPLING
47.30 Figure 4-9.Titrbine and locked train double reduction gearing installed on a DD-692 class destroyer. drive mechanism to change both the speed and hich effects the speed reduction, is called a the direction of shaft rotation. In order that duction gear. both the engine and the propeller may operate efficiently,the enginein many installations DUCTION GEARS includesa' devicewhich permitsaspeed reduction from the engine to the propeller shaft. Turbines must operate atrelatively igh This device, which is a combination of gears and speeds for maximum efficiency, where
39 45 FIREMAN
propellers must operate at lower speeds for the first reduction shaft and the second maximum efficiency. Reduction gears are used, reduction gear on the propeller shaft therefore, to allow both the turbine and the propeller to operate within their most efficient (6000 + 2 = 3000 + 10 = 300). revolutions per minute (rpm) ranges. A typical reductio4gear illustration is shown in figure 4-9. For a typical example of a double reduction The use of reduction gears is by nomeans application, let us consider the main reduction limited to ship propulsion. Other steam gear installation on a DD-692 class destroyer, turbine-driven machinery, such as ship's service shown in figure 4-9. generators and various pumps, also has reduction The cruising turbine is connected to the-high gears. Inlese units of machinery, as well as in pressure turbine thrOugh a single reduction gear. shipboard propulsion units, turbine operating The cruising turbine rotor carries with ita efficiency requires a higher rpm range than that pinion which drives the cruising gear (coupled to suitable for the driven unit. the high pressure turbine shaft). The cruising Reduction gearing in many current turbine rotor and pinion are supported by three. combatant ships makes use of double helical bearings, one at the forward end of the turbine gears. The use of 41ouble helical gears produces a and one on each side of the pinipn in the smoother actiqn,to,of the reduction gearing and cruising reduction gear case, avoids tooth shock. Since the double helical gear The high pressure and low pressure turbines has two sets of teeth at complementary angles to are connected to the propeller sh.. through a each other, the end thrust, such as developed in locked train type double reduction"Year, shown single helical gears, is thereby eliminated. in figure 4-10. (Note: This type of reduction gear is used aboard many naval combatant Reduction gears are classified by the number of steps used to bring about the speed reduction ships.) First reduction pinioni are connected by and the arrangement of the gearing. A gear flexible couplings to the turbines. Each of the rriechanism consisting of a pair of gears first reduction pinions drives two first reduction or a gears. A second reduction (slow speed) pinion is small gear (pinion) driven by the turbine shaft, attached to each of the first reduction which drives a large (bull), gear on the propeller gears by a shaft directly, is called a SINGLE REDUCTION quill shaft and flexible couplings. These four GEAR. In this type of arrangement the ratio of speed reduction is proportional to the diameter LOW PRESSURE 1st of the pinion"and the gear. For example, in a 2 REDUCTION GEARS tow Pansto1 2.4 SEDUCTION PIN* toI single reduction gear the diameter of the MAIN driven gear is twice that of the driving pinion; EAR and in a 10 to 1 single reduction gear, the tow PRESSURE Is, diameter of the driven gear, is, 10 times that of REDUCTION MON the driving pinion. Ships built since 1935 have DOUBLE REDUCTION PROPULSION GEARS. In this type of gear, 4--Ngh-speed pinion, connected to the turbine shill' by a flexible coupling, drives an- intermediate (firstjeduction) gear which is WON PRESSURE In connected by a shaft to the low-speed pinion; .EDUCTION PINION this, in turn,drives the bull gear (second reduction) mounted on the propeller shaft. For HIGH PRESSURE No example, a 20 to 1 (6000-300) speed reduction NON PRESSURE Ilt REDUCTION PINIONS might be accomplished by having a ratio of 2 to SEDUCTION GEARS 1 (6000-3000) between the high-speed pinion and the first reduction gear, and a ratio of 10 to 47.27 1 (3000-300) between the low-speed pinion on Figure 4-10.Locked-train typo gearing.
40 4V Chapter 4SHIP PROPULSION
pinions drive thsecond reduction (bUll) gear Thearrangemeni\ ofthecomponents wtich is atta to the propeller shaft. depends on the type and size of the installation. In some smallinstallations, the clutch, the CLUTCHES AND reverse gear, and the reduction gear may be REVERSE GEARS combined in a single unit; in other installations, the clutch and the reverse gear may be in one housing and the reduction gear in a separate Clutches are normally used on direct-drive housing attached to the reverse gear housing. propulsionengines toprovideameans of disconnecting the eivi" from the propeller To large engine installations, the clutch and shaft.In small enginei clutches areusually the reverse gear may be combined; or thy may combined with reverse .gears and are used for be separate units, located betweerk the engine maneuvering the ship. In large engines special and a separate reduction gear; or the Clutch may types of clutches are used to obtain special beseparateand thereversegear may be couplingorcontrolcharacteristicsandto combined. prevent torsional (twisting) vibration. Inmost geared-drive,multiplepropeller Reverse gears are used on marine engines to ships he propulsion units are independent of reverse the direction of rotation of the propeller eachOther. An example ofthistype of shaft, during maneuvering, without changing the arrangement is ill9strated in figure 4-11. direction of rotation of the engine. They are used principally on relatively small engines. If a In some installations the drive mechanism is high - output engine has a reverse gear, the gear is arranged so that two or more engines drive a used for low-speed operation only and does not single propeller. This is accomplished by having havefull-loadandfull-speedcapacity.For the driving gear, which is onor connected maneuvering ships with large direct-propulsion tothe crankshaft of each engine, transmit engines, the engines are reversed. power to the driven gear on the propeller shag. Inonetypeof installation,each of two Diesel propelling equipment on -a boat or a propellers is driven by four diesel engines (quad ship must be capable of providing backing-down power unit). The arrangement of the engines, power as well as forward power. There are a few the location of theduction gear; and the ships and boats in which backing down is direction of rotation of the crankshaft and-ttie accomplished by reversing the pitch of the prokpeller shaft in one type a "quad" power propeller; in most ships, however, backing down unit are illustrated in figure14 2. is accomplished by reversing the direction of rotation of the propeller shaft. In mechanical The drive mechanism' illustrated includes drives, reversing the direction of rotation of the four clutch assemblies (One mounted to each propeller shaft may be accomplished in one 9f engine flywheel) and one gear box. The box two ways; by reversing the direction of.engine contains two drive purns and the main -drive rotation or by using the reverse gears. gear. Each pinion is driven by the clutch shafts of two engines, through splines in the pinion The drive mechanism of a ship or a boat is hubs. The pinions drive the single main gear, required to do more than reduce speed and which is connected to the propeller shaft. reverse the direction of shaft rotation.Itis frequentlynecessarytooperatean engine Friction clutches are commonly used with withouthavingpowertransmittedtothe smaller,high-speedengines, up to 500 hp. propeller. For this--feason, the drive mechanism However,certainfrictionclutches,in of a ship or boat must include a means of combination with a jaw type clutch, are used disconnecting the engine from the propeller with engines up to 1,400 hp; and pneumatic shaft. Devices which are used for this purpose clutches, with a cylindrical friction surface are are called clutches. used with engines up to 2,000 hp.
41 47' UJUICATENGSERV= eaPUMPS HEAT EXCHANGER FRESH WATER LUBRICATINGea COOLER PRESSURE -FUEL ca AHDCU REDUCDO STRAINER1.111=ATING VALVE AIR STRAINERS GENERATOR.100 KW D3I5E1 SET COOLING CIRCULATING PUMP REDUCTION GEAR TANK LUIRECATING FILTER CP AIR TANKS 1 eN -114 HAND PUMP FUEL Oil GA E 60 KW DUEL k...:1 ... ''- - ... - I --s II LLBRCATNGC3 HAND PUMP EXPANSION TANK FRESH WATERtmoG GENERATOR UT I EXPANSION TANK FRESH WAGER REDUCTION 6 5 V(35 GALLONS) FORWARD STARBOARD SMEDG.SEIL ENGINE k rL _ _ _ _ (330 GALLONS) DAY TANKFUEL CM _7° 05 GALLONS) GEAR ao DIES PORT SIDE ENGINE PRESSURE TANK FU'a ca _ SPECIAL SERVICE DIESEL GENERATOR SET 0 DAY TANKFUEL ca. AFT Ca HAND PUMPLUUSCATTX3 (300 GALLONS) \\10 REDUCTION GEAR ODRIP TAMFra 4E1 1111111111 GENERATOR SET60 KW DIESEL [MORON GEAR LURRtCATINGSERVICEFUEL 433. PUMPS HAND 0:1 PUMP COOLING CIRCULATING PUMP HEAT EXCHANGER FRESH WATER 1.11113CATDOC11 COOLER USLIUCATING tOAIDoAat Figure 4-11.Example of independent propulsion units. y LUIRICATEN34= FILTER ea STRAINER AND LMVCEBEGAIR STRAINER VALVE 75248 Chapter 4SHIP PROPULSION
75.249X Figure 4-12.Four engines (quad unit) arranged to drive one propeller (GM 6-71).
Friction clutches are of two general styles; clutches, and bronze, cast iron, or steel el for wet thediskand the bank styles.Inaddition, clutches. Cast iron surfaces are preferred because friction clutches can be classified as dry or wet of their betterbearing qualities and greater types,dependingonwhetherthefriction resistance to scoring or scuffing. surfaces operate with or without a lubricant. The designs of both types are similar, except Force-producing friction is needed to engage that the wet clutches require a large friction area the frictiopclutches and can be obtained either reduced by mechanically jamming the friction surfaces becauseof the frictioncoefficient together between the lubricated surfaces. The advantages bysometoggle-actionlinkage,or of wet clutches are smoother operation and less through stiffsprings(coil,leaf,orflat-disk wear of the friction surfaces. Wear results from type). The operation of frictionclutches is slippage between the surfaces not only during discussed in the paragraphs which follow. engagement and disengagement, but also, to a certaip extent, during the operation of the TWIN-DISK CLUTCH AND GEAR mechanism. Some wet type clutches are filled MECHANISM.One of theseveraltypes of with oil periodically; in other clutches the oil is transmissions used by the Navy isthe Gray apart of the engine-lubricating system and is Marine transmission mechanism. Gray Marine high-speed diesel engines are generally equipped circulated continuously. Such a friction clutch with a combination clutch and a reverse and incorporatesprovisionswhichwillprevent worn-off particles from being carried by the reduction gear unitall contained in a single circulating lubricating oil to the bearings, gears, housing at the after end of the engine. etc., The clutch assembly of the Gray Marine transmission mechanism is contained in the part Thefrictionsurfacesaregenerally of the housing nearest the engine. It is a dry constructed of different materials, one being of type, twingdisk clutch with two driving disks. cast iron or steel; others are lined with some Each disk is connected `through shafting to a asbestos-base composition or bronze for dry separate reduction gear train in the after part of
43 49 FIREMAN the housing. One disk and reduction train is for power. To maintain the weight and size of the reverse rotation of the shaft and propeller; the mechanism as low ossible, special clutches other disk and reduction train is for forward' have been designed or large diesel installations. rotation. One of these ise airflex clutch and gear assembly used with General Motors 12-567A JOE'S CLUTCH AND REVERSE GEAR.A engines on LST's. typical gear mechanism found on manypower boats is Joe's clutch and reversegear, shown in A typical airflex clutch andgear assembly figure4-13.The drivefromtheengine for AHEAD and ASTERN rotation, is shownin crankshaft is taken into the clutch andreverse figure 4-14. There aLe two clutches,one for gear housing by an extension of the crankshaft forward rotation and tone forreverse rotation. drivegear.Thecrankshaftrotation is The clutches, bolted to the engine flywheel, transmitted to the reduction gear shaft through both rotate with the engine at all times at engine the clutch and the reverse gear unit. speed. Each clutch has a flexible tire (or gland). on the inner side of a steel shell. pefore the tires AIRFLEX CLUTCH AND GEAR are inflated, they will rotate out of contact with ASSEMBLY.On thelargerdiesel-propelled the drums, which are keyed to the forward and ships, the clutch, reverse, and reductiongear reverse drive, shafts. When air under pressure unit has to transmit an enormous amount of (100 psi) is sent into one of,the tires, the inside
DISK CLUTCH
PLUNGER BEARING, CAGE
TOGGLE ASSEMBLY CONE CLUTCH
(dialr3 rFRONT COVER
1 ENGINE SHAFT
COLLAR AND YOKE REDUCTION / BRAKE GEAR SHAFT-lk>. BAN ENGINE SLEEVE PROPELLER PINION GEAR DRUM DRIVE. SLEEVE LONG) PINION GEAR ( SHORT )
75.254 Figure 4-13.attaway view of Joe's clutch andreverse gear:
44 5 Chapter 4SHIP PROPULSION
MAIN GEAR D CLUTCH
FO WARD DRUM
SPACER PROPELLER FLANGE IR SHAFT
AIR CONTROL HOUSING FORWARD PINION AHEAD
MAIN REVERSE PINION REVERSE DRUM REVERSE CLUTCH
REVERSE SHAFT
ASTERN
REVERSE STEP-UP PINION 75.247 Figure 4-14.Clutch and ie verse-reductiongear assembly.
diameter of the clutch decreases. This causes the transmitted because of the principle of relative friction blocks on the inner tire surface to come motion between the two I'otors. Thepower loss in contact with the clutch drum, locking the resulting froWehe small amount of slippage is drive shaft with the engine. transformed into heat which is absorbed by the oil in the system. HYDRAULIC CLUTCHES OR COUPLINGS.The fluidclutch (coupling) is Comparedwithmechanicalclutches, widelyused on Navy ships. The use of a hydraulic clutches have a number of advantages. hydraulic coupling eliminates the need fora There is no mechanical connection between the mechanical connection between the engine and driving and driven elements of the hydraulic the reduction gears. Couplings of thistype coupling. Poweristransmitted through the operate with a small amount of slippage. coupling very efficiently (97 percent) without Some slippage is necessary for operation of transmitting torsional vibrations, or load shocks, thehydrauliccoupling,sincetorque is from the engine to the reductiongears. This 45 51 FIREM
FORWARD CONNECTED TO CRANksitAFT DIRECTION OF ROTATION
When blades ore In Position shown by solid lines, the propeller Is driving the vessel ahead. When AFT blades ore in position shown by broken line the propeller is driving the vessel astern. CONNECTED TO pRopEsAER 139.56 Figure 4-17.Schematic diagram of a controllable 75.264 pitch propeller. Figure 4-15.Dog clutches.
RAKE type in that they allow the engine shaft to be ANGLE disconnected from the propeller shaft. The dog ! ADIN, OGL clutch ensures a positive drive without slippage and with a minimum amount of wear. (Forward LEADING TRAILING drive is generally accomplished by one set of TRAILING EDGE EDGE EDGE dogs, shown in figure 415, connected to the crankshaft, engaging and turning another set of BACK dogs, connected to the propeller shaft.) FACE In several installations, theftiog clutch is used ROOT in addition to a friction clutch; the dog clutch is engaged after the friction (or synchronizing) clutch brings the two shafts to an equal speed. HUB The engagement of the dog clutch eliminates slippage and holds friction clutch wear toa A B minimum.
147.46 PROPELLER Figure 4-16.Propeller blade. The screw-type propeller consists of hub and blades (usually three or four) all spaced at equal protects the engine, the gears, and the shafting angles about theaxis. When the blades are from sudden shock loads which may occur as a integral with the hub, the propeller is known as resultof pistonseizureorfoulingof the aSOLID propeller.When thebladesare pro eller. The power is transmitted entirely by separately cast and secured to the hub with the circulation of a driving fluid (oil) between studs, the propeller is refetred as a BUILT-UP ra la' passages in a pair of rotors. In addition, propeller. th'assembly of the hydraulic coupriiig will Some of the parts of the screw propeller are a sorb or allow for slight misalignment. identified in figure 4-16. The FACE (or pressure face) is the afterside of the-blade when the ship D 0 G, C L UTCH E S. Dog-typeclutches is moving ahead. The BACK (or suction back) is perform much the same function as the friction the surface opposite the face. As the propeller
46 -'-52 Chapter 4SHIP R,ROPULSION rotates, the face of the blade increases pressure or aft) and where the tip would be if itwere in on the water to mekve tt in % positive astern perpendicular position. movement. The overall thrust, or reaction force A screw propeller may be broadly classified ahead, comes from the it cr!ted watervelocity as moving astern. FIXED PITCH OR CTR LLABLE PITCH. The'pitch ofa ed pitch ppeller The TIP of the blade is' the most distant cannot be altered duringperation; the p tch of from ,the hub. The ROOT of the bladeis the a controllable pitch pro eller can be dh area ged at wheretheblade joins the hub. The any time, subject to bridgeor engineroom LEADING EDGE is the edge which first cuts the control. The controllable pitch propellercan water when theship, isgoing ahead. The reverse the direction of a ship without requiring TRAILING EDGE (also called the following a change of direction of the drive shaft. The edge) is opposite the leading edge. blades are mounted sd that eachone can swivel A RAKE ANGLE, exists when the tip ofthe or turn on a shaft which is mounted in the hub, pfopeller blade is not precisely perpendicularto as shown in figure 417. Most propellers in naval the axis (hub). The angle is formedby the ships are of the fixed pitch type,but some distance between where the tip really is(orward controllable pitch propellers are in service.
53
t. 47 CHAPTER 5
BASIC STEAMCYb.ES
Ina dition to knowing hav steam, is the!water and the.steamcirculate'throughout generate, youmust know what happens to the entire cycle of operatiOn Vithout eVeribeing steam af er it leaves the boiler. One of the best expbsed to the atmosphere.:., ways to learn about the'steam plant on your own ship is to trace the path of steam and water A discussiofollows or the four basicreas throughout its entire cycle of operation. In this of operation insteam cycle, shown, in figure chapter, the main steam cycle and the auxiliary 5-1: part Agener tion; part Bexpansion; part steam.cycle are discussed. In each of these cycles Ccondensatio nd part 15feed.
,.***" amewom doom .0*4...Nom am.. 1.0100 0101 .. :IMMOWry.INIMM 1B EXPANSION 1IA GENERATION CRUISING, TURBINE
1.1)GH IL ER';,. I I PRESSURE I I TURBINE
girERtiF ATE?
%.331.111.111.111..A.
..i1'..1%1*; IN..; =NM* 111.1. j ,0.4/0Mi.10110
I
MAIN FEED I PUMP' I I
I FEED CONDENSATE .1 AIR a BOOSTER I PUMP . PUMP EJECTOR D FEED IS CONDENSATE 01111.11 m.o.. oar.= aa.o. ONO.. 11110111M, =1.
38.2 Figure 8.1.Diagrammatic, arrengement (the main steam cycle.
48 Cha;ter SBASICSTEAM CYCLES
MAT STEAM CYCLE The` -steani inthe steam drum is called SATURATED STEAMthis is steam which GENERATION' has not been heated above the temperatureof the water from which it was generated. Saturated To generate steam, it is firstnecessary to steam Is used aboard ship to operate heat water to its boiling point and then most of the add a auxiliary equipment and also in thevarious sufficient amount of heat to change (convert) types of heaters. the boiling water into steam. The heat.required to change boiling water into steam,at any given It is impossible to raise the temperature temperature of. the boiling water, is called the of latent saturated steam without also increasingthe heatofvaporization.When steam pressure as long as the steam is in contact with condenses back to water (at boiling point),an the water from which it is formed. equal amount of heat is given off; However, the it is called the steam canbeheated aboveitssaturation latent heat of condensation. Theamount of heat tejnperature if it is first drawn off into'another required to convert boiling water to steam, or vessel, where it is no longer in contactwith the the amount of heat given; off whensteam is water, and if additional heat is applied. condensed, backtowaterat Steam -itsboiling 'which has been heated aboye itssaturation temperature,varies with the pressure under temperatureisknown which the Kocess takes place. Part as SUPERHEATED A of figure STEAM. The device which allows thisextra heat 5-1 illustrates the generationarea of the cycle. tobe added to the steamis known as a Thereare SUPERHEATER. Figure 5-2 showsa simple definitepressure-temperature form of both a boiler anda superheater. relationshipsinvolvedinthe generatioh of steam. The boiling point of water is 212° Fat Most naval propulsion 'boilers sea level, where the atmospheric pressure is 14.2 are equipped with superheaters. Superheatedsteam has many psi., At higheraltitudes, where atmospheric advantages over pressureis saturated steam for use in reduced, water boilsata . lower propulsion machinery.Because the steam is dry, temperature. If the pressure is increased, the it causes relatively little corrosion boilingtemperature or erosion of of water willalsobe piping and machinery. In addition,superheated increased. In a boiler operating undera pressure steam does not conduct heat of600psig,watermust as rapidly as beheatedto saturated steam; therefore, it doesnot lose heat approximately 48° F. to make it boil. In boilers as rapidly. The use of superheated steam operating under a viciressure of 1000 for psig, water propulsion purposes greatly increasesthe overall must be heated to approximately 544°F to efficiencyof make it theengineeringplant;this boil. Therefore, the boiling point of increased efficiency results inlarge savings in water is determined by thepressure. fuel consumption, and inspace and weight requirements. It is important to note that thetemperature of steam is determined by the temperature at Since most auxiliary machinery isdesigned which the water boils, as longas the process is to operate on saturated steam, naval taking place in a closed vessel boilers are or in a closed designedtoproducebothsaturatedand ' system such as a boiler. As longas the pressure superheated steam. remains constant, steam in contact withthe w&ter from whichitis being formed must remain at the same temperatuitas the ,boiling EXPANSION water. Therefore, in a boiler operating undera pressure of 600 psig, the temperature of the The expansion portion of the main steam gleam in the stem drum must be approximately cycle is that part of the. cycle in whichsteam is 489° Fthe, same temperatureas the boiling led from the boilers to the main turbines water. (The tsteam drurn,of the boiler is and a sealed expanded in those turbines toremove the heat chamber that holds tne., water and steam.) energy stored in the steam and to transform that 49 55 FIREMAN
SATQRATED. fsunntiu401sT.EAm
FEED WATER
GENERATING SUPERHEATER FURNACE FURNACE
Figure 5-2.Elementary boiler and superheater.
THERMOMETER CONNECTION AUXILIARY EXHAUST EXHAUST STEAM STEAM INLET INLET
VACUUM , OVERBOARD DISCHARGE AIR OUTLET CONNECTION
RECIRCULATING . CONNECTION VE T THERMOMETER CONNECTION ZINC PLATE
HOSE CONNECTION
IMPINdEMENT BAFFLE 1!P rfr TUBESUPPORT/ LUKE OIL COOLER r FIBER CONNECTION BRINGS AIR BAFFLE CIRCULATING METALLIC PUMP RINGS CONNECTION
TUBE END DETAIL HOT CONDENSATE WELL OUTLET SCOOP INLET
47.70X Figure 5-3.Cutaway view of a main condenser.
50 56 Chapter 5BASIC STEAM CYCLES
energy into mechanical energy of rotation. The water and flows from the main main steam system is the piping condenser (fig. system which 5-3) toward the boilers whileit is being prepared leads the steam from the boilersto the main for use as feed water. turbines.
The 'main turbines generally The several components of thecondensate consist of the system, in sequence, from the lowpre ure cruising turbine, highpressure turbine, and the turbineare:(1) main condenser, (2) gin low pressure turbine: The steammay flow into condensate pump, and (3) the main, the cruising turbine, then to the air ejector. high pressure (See fig. 54.) These componentsare shown in turbine and on into the lowpressure turbine; or part C of figure 5-1. the cruising turbine may bebypassed. Some main turbine installations do not have a cruising The main condenser receives thesteam from turbine. Part B of figure 5-1illustrates the the low pressure turbine and expansion portion of the main condenses the steam cycle; it steam into water. The maincondensate pump containsthecruisingturbine,highpressure takes suction from the main turbine, and low pressure turbine. condenser and delivers the condensate intothe condensate piping system and through CONDENSATION the main air ejector. As its name implies, the air ejectorremoves the air that was picked Since each ship must produce up in the main condenser. sufficient The condensate, after passingthrough the air quantities of feed water for the boilersand since ejector, enters the vent condenser a marine engineering plant must be section of the as efficient deaerating feed tank before enteringthe tank. as possible, the feed water must be usedover and over again. FEED As the steam leaves or exhausts fromthe low pressureturbine,itentersthe condensate Thedeaeratingfeedtank(fig.5-5)is system. The condensate system isthat part of sometimesconsidered the steam cycle in which the steam asthedividingline condenses to between condensate and feedwater. This tank
FIRST STAGE SECOND STAGE AFTER AIR EJECTOR IN VENT TO EJECTOR CONDE SER ATMOSPHERE (VIA EXHAUST FAN)
AUX. STEAM AUX. STEAM GLAND EXHAUST EXHAUST VEN'T STEAM 11P.
TO D AERATIND TANK
GLAND EXHAUST DRAIN CONDENSER
INTER CD CONDENSATE CONDENSATE LOOP CONDENSER PUMP REAL Gn VAPOR 1=1 STEAM
47.77X Figure 5-4.Flow diagram ofa two-stage air ejector.
51 FIREMAN
SPRAY AIR VALVES OUTLET
RECIRO ( LATION.
STEAM WATER I INLET INLET _ 21, toOree' VENT. AIM10,14'. HIGH CONDENSER ee PRESSURE e INA
OEAERATING UNIT
CtiECK. VALVE CONTROL
a
1ga
WATER OUTLET
38.17 Figure 5-5.Deaer tited tank. 58 52 Chapter 5 BASIC STEAM CYCLES
hasthreebasicfunctions:(1)tofreethe condensate of all trapped economizer tubes. As .aresult the water is oxygen and air, (2) to approximately 100° F hotteras it flows out of heat the water to a degree whichwill allow the the economizer to the boiler. economizertointroducealltheremaining necessaryheatbefore dischargingitto the beater, and (3) to act as a reservoir in which to AUXILIARY STEAM CYCLE store water to take care of rapidincreases in feed needs and to absorbsudden' increases or The generation rges of the condensate. spction of the auxiliary steam cycle is the sameas the main steam cycle. The main difference is that theauxiliary steam As the condensate enters thedeaerating feed does not go through a superheater. tank,-it is sprayed into the Therefore, dome of the tank by the auxiliary steam in allcases is a saturated nozzles: Here itis discharged ina fine 'spray steam. throughout the steam-filledtop or preheater. The break up of the condensate intoa fine spray Anotherdifferenceoccursbetweenthe releases the trappedoxygen and air from the generation and expansion sections.Note that in condensate. The air-free, oxygen-freecondensate figure 5-6, the line that carriesthe steam to the falls to the bottom of the tank, whilethe air and auxiliary equipment (whereexpansion takes oxygen are exhausted from the tank. place) has a number of linesleading to various pieces of equipment suchas main feed pumps, , The condensate thatiscollected inthe mainfeed booster pumps, maincondensate storage section of the deaerating feedtank is pumps, main tube oil pumps, and steam reducing now called feed water and becomesa source of valves, just to name a few piecesof equipment, supply for the main feed boosterpump. The serviced by the various fap offs.In the main main feed booster pump takes suctionfrom the steam cycle, only the main turbinesare serviced deaerating feed tank and maintainsa constant bythemain steamline.Another major discharge pressure to the main feedpump. differenceisthat after 'expansion hastaken place, the exhaust steamdoes not go directly The main feed pump picksup the water into the main i5r auxiliarycondenser (fig. 5-7) (deliveredfrom theboosterpump)and but goes into an auxiliary exhaustheader and discharges it into the main -feed pipingsystem. then to either the mainor auxiliary condenser Part D of figure 5-1 illustrates thepath of the via an unloading valve (fig. 5-8).Normally, in water from the deaerating feed tankto the port the auxiliary steam plant willbe used. The economizer. The dischargepressure of the'main unloading valve associated withthe plant that is feed pump is usually about 150 psigreater than in operation will be used. Theunloading valve the boiler operating pressure. For example,the maintains about 10-15 pounds ofexhaust steam dischargepressuceof, amainfeed pump,42, pressure on the exhaust steam header for plant Aft charging to a Oiler operatingat 600 psi, will efficiency. normally be 750,..01. The dischargepressure is The condensation section maintained throughout the main feed of the steam cycle piping isthe same process in boththe main and system;however,thequantityofwater auxiliary steam cycles. The discharged to the economizer is controlled system where salt by a water is used in a heat ,exchanger(main or feed stop arid check valveor automatic feed auxiliary condenser) tto turn water regulator valve. the low pressure or exhaust steam back tccondensatefor future use iscalledaconderming section. The The economizer is positionedon the boiler basic 'to perform one basic function; diffIrence is that the maincondenser will'not that is, to act as a alwrys be usedas a heat sink in the auxiliary preheater. The gases of combustion flowaround steam cycle. As stated before, in the economizer tubeshich absorb some of the most cases in port you will be using the auxiliarycondenser eat of combustion, anthe economizer in turn and the associated auxiliary heatsthe water that is equipment will be flowing through the used to operate the auxiliarysteam plant.
53 59 FIREMAN
2 OtGR** =tom 2 FtR2 ROOM iworm wpm FIRE ROOM
AostSio.
to 4 O...0.4 Ljt t*trot.0.1 nini
DEM OPERATED
30.18 Figure 8-6.Adicillary steam system.
GENERATC$,TURIINE EXHAUST INLE
THERMOMETER CONHECTIO tr
DETAIL OF TUBE ENDS
GENERATOR TURBINE EXHAUST INLET
CIRCULATING CONNECTION STRAINER
CONDENSATE OUTLET
RELIEF VALVE ..r." CONNECTION }-:VIPH. WATER `'-"" OUTLET :11
FEED TANK VENT
EXPANSION JOINT
CONDENSATE PUMP VENT AIR EJECTOR SUCTION EVAPORATOR DRAIN
0.1 MAKE UP CONNECTION FEED WATER THERMOMETER DRAIN TANK VENT WATER INL CONNECTION
47.71 Figure 5-7.Auxiliary condenser.
54 6O b Chapter 5BASIC STEAMCYCLES
'1
GAT VALVE
$TR INER
'A* UNLOADING VA VE .-/TILNJILm 'r 0,1Lifil 7"
NUM. *E1Y-PASS DIAPHRAGM VALVE MPH AGM R SEAL DIAPHRAGM SPRING ADJUSTING SCREW MANUAL CONTROL VALVE WHEEL 4
47.61 Figure 5- 8.- -Swartwout unloading valve.
The feed system is the same with one major auxiliary pump can be used to supplythe head difference, thatis,in port an auxiliary feed of waterto booster pump (electric driven) the emergency feedpump (a can be used reciplTating pump) insteadof the main feed instead of the main feed boosterpunip to take pump which, in turn, will feed the water back suctiononthedeaerating feedtank. This to the boilers to be converted back tosteam.
61
55 CHAPTER 6
BOILERS
This chapter gives you basic information on ofater.) In Addition to these basic functions, boilers and operating principles. We shall thsteam drum either contains or is connected discuss boiler c nstruction and the major parts to many of the important controls and fittings andtheirfctions.Also,youwillfind required for the operation of the boiler. numerous fire oom safety precautionswhich ) must be observed when boilers are being fired. At the bottom right side of the boiler you will find thewater drum and on the bottom left side is another drum, the header,, or sidewall BOILER ASSEMBLY header, shown in figure 6-3. The waterdrum is larger than the header, but both are smaller than A boiler is that part e s eam cycle in the steam drum. They equalize the distribution which water is Converted nto steam. The boiler of water to thegerieiatirig tubes and collect the consists of me al drum eaders and tubes, and deposits of loose scale and other solid matter accessories fo con ing steam pressure and which may be present in the boiler water. The temperature:ndotheraspect*, ofboiler drum and header each has a blowdown valve. operation. Y ,u illalso find a furnace with When the valve is opened, some of the water is casing and uake; steam and water drums; forced out of the drum or header and carries the generating, circulation, and water screen tubes; a loose scale, sediment, or dirt with it. superheater; an economizer; and the necessary piping and accessories to ensure an ample supply At each end of the steam drum are a number of fuel, water, and air. of large tubes (fig. 6-4) that lead to the water drum and sidewall header. These tubes are the A cutaway view of a D-type boiler is shown downcomersthroughwhichwaterflows in figure 6-1. As we continue our discussion on downward from the steam drum to the water boiler assembly, imagine that you are assembling drum and the header. The downcomers range a similar boiler. As you addeach part to your diameter from 3 to 8 inches. boiler, follow the line drawing that describes the position of that part. A great number of other tubes also link the steam drum to the water drum and the steam The steam drum (fig. k-2) is a cylinder, drum to the header. The several rows of tubes located at the top of the boiler, and it runs that lead from the steam drum to the water lengthwise _from the front to the back of the drum are the generating tubes (fig. 6-5) which boiler. The steam drum provides a space for the are arranged in the furnace so the gasesand the accumulation of steam generated in the tubes heat of combustion can flow around them. The and for the separation of moisture from the large arrows in figure 6-5 show the direction of steam./It also sery s as a storage space for boiler flow of the combustion gases. water, which is tributed from the steam 'drum tothe down mer tubes.(During normal The generating tubes are made of steel that operatiA, the steam dram is kept about half full is strong enough to withstand the high pressures
56 62 Chapter 6 BOILERS
'SURFACE BLOW 1
I OXFFL E MATERIAL I !FEED WATER OUTLET)
I AIR !m.o.!.
PLASTIC CHROME ORE I Ff I SUP.ERNEATER
124. INSULATING OLOCK
11% SPLIT INSULATING BRICK)
IVSPLIT FIREBRICK
PEED WATER' INLET
SOT oLOortwe
I Me PLASTIC FIREORICK
[MS FIREORICK
11,14" INSULATING FIREBRICK!
V INSULATING OLOCK 1 L.tca:14ItTiplAL
?IS FIREBRICK INSULATING BLOCK
2/3"INSULATING FIREORICK PLASTIC CHROME ORE ) I l'INSULATING BLOCK )
38.40 Figure 6-1.Cutaway view ofa D-type boiler (older type). 63
57 FIREMAN 7 7 T~i
SIDE VIEW END VIEW 139.13 Figure 6-2.Steam drum.
OOWNCOMERS
139.15 Figure 6-4.Addition of downcomer tubes.
BOTTOM BLOW DOWN VALVE
OOWNCOMERS
139.14 Figure 6.3. Steam drum, water drum and header.
and teperatu es within the boiler. In most boilers these to are usually 1 to 2 inches in diameter, but there may be some that are 3 inches. These small tubes present a large surface area to absorb the heat in the furnace.Note that a 2-inch tube has twice thesurface area of a 1-inch tube, but four times the volume. A 3-inch tube has 3 times the surface area of a 1-inch tube, but 9 times the volume. The smaller the .diameter of the tube, the higher is the ratio of absorption surface to the volume of water. Normally there is only one row of generating 139.16 tubes leading from the steam drum to the Figure 6-5.Adding generating tubes and furnace area.
58 64 Chapter 6BOILERS
sidewall header. Theseare the sidewall (water wall) tubes which provide,a cooling effect to protect the side wall of the furnade. So far we have assembled thedrums, header, downcomers, and the generatingtubes. Before going any further with theassembly, let us trace the path of the water throughthe boiler. The water flows out of thesteam drum down through the downcomers intothe water drum and the sidewall header. As thewater is heated it forms a vapor (steam) thatis lighter than the water in which it is contained.The steam rises through the generating tubesand returns to the steam drum. The arrows in figure6-6 show the circulation path of the boilerwater as it leaves 4. the steam drum andas it returns to the steam drum as steam. The furnace, or firebox (fig.6-5) is the large, room-like kpace where air andfuel are mixed for the combustion of the fuel(fire). The fire heats the water thatisin the drums, tubes, and 38.40 headers. Figure 6-7.Refractory lined furnace.
The furnace ismore or less a rectangular 1 steel casing which is linedon the floor, front wall, side walls, andrear wall with refractory (heat resisting) material.Refractory materials used in naval boilers includefirebrick, insulating brick, plastic firebrick, andair-setting mortar.
COOLER WATER FLOWS DOWN The refractory liningprotects the furnace steel casing and preventsthe loss of heat from the furnace. The refractoriesretain heat for a MIXTURE Of relatively long period of HOT WATER time and thus help to AND STEAM maintain the high furnacetemperatures that are FLOWS UP needed for complete combustionof the fuel. Figure 6-7 shows a refractorylined furnace.
HOT Therearemanydifferent GASES typesof refractories. Each type isused according to its physicalandchemicalpropertieswhich determine the refractory'slocation within the furnace.Somerefractorymaterialscan withstand greater temperaturesthan others and are positioned nearer to the intenseheat of the fire.
Inchapter 5youdiscoveredthatan 139.17 economizer is positioned Figure 6-6.--Natural circulation (accelerated on the boiler (fig. 6-8) type). where it acts as a pre-heater.It absorbs heat
59 6 5 FIREMAN
One more basic component is needed to 0 00 complete the water-steam flow path-. From your study of the steam cycle do you remember what 1000 that"' component might be? In chapter 5 you 0 0 0 were told that the steam, as it leaves the steam drum on its way to the main turbines, passes through a superheater. The superheater (fig. 6-1Q) is constructed) af a number of U-shaped tubes which are insta ed horizontally projecting forward into the furnace. The superheater tubes are connected to the superheater headers which are installed vertically at the rear of the boiler; one end of the tube enters one header and the other end of the tube enters the other header. (SomesupeIheaters are of the vertical type with horizontal headers.) The superheater tubes are positioned in the boiler that they are SUff0 nded by the generating' tubes. They are also plad so the hot gases of combustion flow overand arou d them. Figure 6-11 shows the relative position of the superheater tubes installed -irr the boiler. You have now assembled the major parts of the 139.18 boiler. Look again at the assembled boiler shown Figure 6-8.Relative position of economizer. in figure 6-1. Identify the component parts and review their functions. FUEL OIL BURNERS
11.1P1.4eqleitittiliiii Now that you have assembled the major components of the basic boiler, you are ready to ittirkt inject the fuel and air into the furnace where ,"14t1i1110141!" combustion takes place. Look at the fuel oil burners that are mountedon,the boiler front A 1:111 LIU (fig.6-12).The complete burner assembly consists of the atomizer, the air registers, and the valves and fittings needed to connect the atomizer to the fuel line.
38.28 ATOMIZERS Figure 6-9.U-bend economizer tube with aluminum gill rings. The atomizers divide or break up the fuel oil into very fine particles as illustrated in figure 6-13. There are three major types of atomizers from.the furnace and transmits this heat to the in use on naval boilers. Straight-through-flow incoming feed water. The economizer is made atomizers are found in the est shi s. The up of a number of tubes which areillustrated in return-flow atomizers (fig. 6-13) used on figure 6-9. The fins on the tube absorb the heat many of the newer ships; you may also find Itom the gases of combustion and in tarn steam-aisist atomizers on some cof the newer transfer the heat to the incoming feed water. ships.
60 66. Chapter 6BOILERS
SUPERHEATER . HEADERS SUPERHEATER HEADERS
SATURATED STEAM INLET
ItIt PASS DRAIN
SUPERHEATER TUBES 2nd PASS
VENT
rd PASS
SUPERHEATED STEAM OUTLET
B DRAIN DRAIN
Figure 6-10.Diagrammatic arrangement of superheater. 38.23
ECONOMIZER i©©©©!I \ ©C)
©@ OC) i ®@ ©® 160 ©©I t ©©0© // ,, wATERWATER WALL,// TUBES /Jo/463 1 SUPER- /ors//c HEATER /4. / TUBES /0 '/ // i/ / GENERATING TUBES
SIDE WALL HEADER WATER DRUM 38.70 38.39 Figure 6-12.Babcock an d Wilco aroline -type fuel Figure 6-11.Relative position of superheater tubes. oil burners installed on a boiler front.
4- 61 6 7 FIRQAN
ORIFICE SPRAYER ATOMIZER DISTRIBUTOR NOZZLE PLATE PLATE NUT HEAD BODY I GOOSE NECK I .14 11111111111111111141111111, IATOMIZER 101 OMAHA iy .r ASSEMBLY -.5414A112"17
tt'AfrAe
dint".4111111illIll 11101 11111111lilimi,'/7, nektklatitkav /f.
OIL LEAVINGWHIRLING OIL RETURN OIL ATOMIZER e° ORIFICE CHAMBER SUPPLY BARREL
38.75 [NOZZLE Figure 6-13.Return-flow atomizer. I SPRAYER PLATE'.
Figu)re6-14 shows an atomizer of the straight through -flow 'type.It consists of five 38.71 majorParts:thetip,sprayer plate; nozzle, Figure 6-14.Parts of a straight-through-flow burner b\a,rrel, and the gooseneck. The nozzle, atomizer assembly. sprayer plap, and tip assembly fit on the end of theburnerbarrel which projectsintothe furnace. The gooseneck fits on the outer end of These grooves are so shaped that the oil is given' the burner barrel. Fuel oil enters the atomizer a high rotational velocity as it discharges into a assembly through the gooseneck and is sprayed small cylindrical whirling chamber in the center into the furnace. of the sprayer plate. The whirling chamber is cone-shaped at the AIR REGISTERS end and has as opening (orifice) at the small end of the cone. The oil leaves the chamber through Air entersthefurnacethroughtheair the orifice and isbroken. up into very fine register where it mixes with the fine oil spray particles to form a cone-shaped fog-like spary. A which entered through the atomizer. Figure 6-15 strong blastof air, which has been given a shows the arrangement of air register part's in a whirling motioninitspassage through the burner assembly. The air register consists of register, catches the oil fog and mixes with it. three main parts: (1) air doors, (2) a diffuser, The mixture of air and oil enters the furnace and (3) air foils. The air doors are used/to open where combustion takes place. orclosetheregister as necessary. They are usually kept either, fully opened or fully closed. CLASSIFICATION OF BOILERS When the air doors are open, air rushes"fn and is given a whirling motion by the diffuser plate. Naval boilers may be classifr.d in a number The diffuser plate causes the ,air to rpix evenly of different ways, according to various design with the atomized oil in such a wa g/. that the features. Some knowledge of these methods of flame will not blow away from the atomizer. classificationwillhelp you understand the The air foils guide the major quantity of air so - design and construction of modem naval boilers. that it mixes with the larger particles of oil spray beyond the diffuser. LOCATION OF FIRE Oil is forced under pressure through the AND WATER SPACES burner barrel. It goes through "the holes in the nozzle (fig. 6-16A) into the tangential grooves of _First of all, boilers are classified according to the rear side of the sprayer plate (fig. 6-16B). the relative location of their fire and water
62 68 Chapter 6BOILERS
INNER CASING
t BURNER OUTER CASING BARREL
II AIR DOOR HANDLE
STATIONARY I AIR FOILS GOOSE NECK =1....:=W41)..4 aI BURNER CONE OPENING I i< I V"se 114 py's.sizzY9 OW -NIA
YOKE
DISTANCE PIECE
MOVABLE AIR DOORS DIFFUSER INNER CASING PLATE. OUTER CASING (BOILER FRONT) BURNER (SIDE VIEW)
BURNER BARREL
BURNER COVER PLATE
AIR (;.:IOR HANDLE
ATOMIZER VALVE
re
BURNER (FRONT VIEW)
38.69 Figno 6-15.Cross-sectional view of Babcockand Wilcox Carolina-type fuel oil burner with sCeight-through -flow atomizer. -69
63
Air FIREMAN
NOZZLE HOLE S
DISHED AND ROUNDED FACE
A
FLAT FACE 7 J
:Mt 38,/2X Figure 6-16.Nozzle and spreyor plate showing holos, groove and whirling chombor. spaces. By this method of classification, all of some older merchant ships. However, these boilers maybedividedintotwogroups: boilers are not suitable for use on modern naval fire-tubeboilersand water-tubeboilers.In shipsecause of their excessive weight and size, FIRE-TUBE BOILERS, the gases of combustion the excessive length of time required to raise flow through the tubes and heat the surrounding steam, and thAjnability to meet demands for water. In WATER TUBE BOILERS, the.,:water rapid speed chitges./ flows through the tubes and is heated by the gases of combustion that fill the furnace. TYPES OF CIRCULATION All boilers used in propulsion plants of naval ships are water-tube boilers. Fire-tube boilers, Water-tubeboilersare --alsoclassified which were once used extensively in marine according to the type of circulation. Natural installations, are still used in propulsion plants circulationboilersarethosein which the 411,' 64 70 Chapter bBOILERS
circulation of water depelidson the difference in this type of superheater isuncommon at the density betWeen a rising mixture of hotwater present time, it may be used again in future and steam,.and a falling body of relatively cool, boiler designs. steam-free -water: Thedifferenceindensity occurs because the water expands as it is heated, FURNACE ARRANGEMENT thus becoming less dense. There are two types of natural circulationfree and accelerated. Aknatuml circulation boilersnow in naval use may also be classified according to the In. FREE CIRCULATION BOILERS, the furnacearrangement.Bythisclassification, tubes which connect the lower andupper drums boilers are either SINGLE-FURNACE BOILERS or headers are 'only slightly inclined to allow the orDOUBLE-FURNACE BOILERS. -lighter hot water and steam to rise whilethe Double-furnace boilers are also referred toas heavier and cooler water descends. Installing the DIVIDED- FURNACE BOILERS. generating tubes at a greater angle of inclination increasestherateofwatercirculation. Therefore, boilers.in which the tubes slopemore OTHER NAVAL BOILERS steeply between the water drums or headers and thesteamdrumareACCELERATED There are many different kinds of boilers CIRCULATION BOILERS. used in naval ships. Earlier in thischapter yc5u studied and assembled the 600 psi D-type boiler. Most modern naval boilers are designed for The other boiler used in naval ships is the1200 accelerated natural circulation. In such boilers, psi boiler shown in figure 6-17. Ngtice that this large tubes (3 inches or more in diameter)are boiler is very similar to the boilershown in installed between the steam drum and the water figure 6-1. However, the boiler in figure 6-17has drums. We discussed, theselargetubes,the some special operating and design features which downcomers when wew assembled the boiler make it' different from the one shown in figure earlierin this chapter. The .downck:rri l'ers,are 6-1. A relatively new boiler thatis presently located outside the furnace (fig. 6-1) andaway installed on some new constructico of from the heat of combustion, thereby serving the DE as 1040 class ship is the pressure fired boilershown pathways for the downward flow of relatively in figure 6-18. Since the cool water. The small pressure fired boiler is tubes, the generating used for propulsion only, those ships that havea tubes, then carry the steam and water upward. rffssurefiredboilerinstalledalso have an auxiliary boiler. TYPE OF SUPERHEATER Auxiliary boilers are not generally usedon seam -drivenshipstbecaute,allsteamfor Oipractically all boilers currently used in auxiliaryserviceistakenfromthe thepropulsionplantsofnavalships,the propulsion-plant boilers. Auxiliary boilersare a superheater tubes are protected from radiant wide variety of small boilers thatare used in heat by water screen tubes. These tubes absorb diesel -driven ships to supply steamor hot watet the intense radiant heat of the furnace, and the for distilling plants, space heating, galleyand superheatertubes areheated by convection laundry services. Auxiliary boilers contain their currents rather than by. direct radiation. Hence, own accessories and controls and operateas a thesuperheatersarereferredtoas complete self-contained unit. The threebasic CONVECTION-TYPE SUPERHEATERS. types of auxiliary boilers in navaluse are (1), fire-tubeboilers(fig.6-19),(2)water-tube On some older boilers, the superheater tubes boilers with natural circulation (fig. 6-20),and w re not screened by water screen tubes but (3) water-tube boilers with faced circulation we e exposed directly to the radiant heat of the (fig. 6-21). fuace. Superheaters of this type are called . Generally, operating pressures of auxiliary R DIANT-TVPE SUPERHEATERS. Although boilers range from 50 psi to 125psi. Most
65 k
.01 -,t,<-;=-17)4044, °O°0°0:::, ei She) fru, 141064,41. 1 (Z..-4,7PreeFLP44 c---77/A:mainexe t'."3 tprii si\\ . 4`, ..px r.^"-g.e---4f,oak.a)),) $os.9.vp10, w AV: di"-144 so)uahuveecmvoac® w 41,11.- ..= - 41*.' ill.. flas* /---*N, .. 1 Ili iv( 4 II \ , Imgr
Atr:t;
,:,....4.11
..,.....:r...... / .1.:1.1...... ,:i.-,,::.:ir :4 .--A....i ,...... -.: '....c...,% A 1.071' 09f.:4 ..'" /
PAL 9 -7" ,...... 447144,---..--. et im.,,,...... ,,_...... 7,-,...... - iv)1r-di ...... almm.....,-..,...-...... r,....:,...... ,... , NI.-avienn el-'1110.1.11:-.---- No/ memion4 -.111Pr,
II s
O 11 Chapter 6BOILERS
139.19 Figure 6-18.Pressure fired boiler.
67 FIREMAN
1 r
139.20 Figure 6-19.Fire-tube auxiliary boiler. operating and maintenance procedures for main than boilers which operate at lower pressures propulsionboilersare alsoapplicableto and temperatures. Boilers operating at 4500 psi auxiliary boilers. and above are now, in use in some stationary steampowerplants.Fornavalpropulsion boilers, such pressuKs are not practicable at the NEW HIGH-PRESSURE present time. However, a number of boilers, BOILERS operating at 1200 psi pressure and at 950° F, havebeeninstalledonnewnavalships. The modern trend in boiler design is toward Increasing use of these boilers will be made. higher 'Pressures and temperatures. High pressure A HIGH-PRESSURE BOILER is any boiler boilers are smaller, lighter, and more economical thatoperatesat700psiorabove.The infuel usage, in any given shaft horsepower, HIGH-PRESSURE,D-TYPEBOILER is .7- 468 / Chapter 6- BOILERS
139.21 Figure 6- Assembly view, water-tube auxiliary boiler (natural circulation).
69 t) FIREMAN
precautions that your petty officers will- tell you. A few important safety precautions are listed here; your petty officers will instruct you in many more:
1.Do not open or close any valve you are not told to open or close.
2.Do not play games of any kind in the fireroom. 3. Do not leavetools lying around the fireroom; always return them to their proper stowage.
Observethefollowing precautions when lighting off a boiler: I.Remove stack cover.
2.Run the water level down untilitis below lighting off level and, then, add water with the emergency feed pump untilitis at lighting off level.
139.22 3.Always purge the f e before lighting Figure 6-21.Amernbly view, water-tuba auxiliary off the first burner. boiler (forced circulation). 4.Standwellcl ar when inserting and withdrawing the torch. natural circulation boiler that is the same as the D-type boiler, wept that it has been modified for higher operatin g pressures. Observe thefollowing precautions during boiler operation: I.Never leave disconnected atomizers in FIREROOM SAFETY place. / ° PRECAUTIONS 2.Keep the atomizer root valves closed to Safety precautions are for your protection as secured burners, except during maneuvering. well as for the protection of machinery and equipment. Whenworkinginasteaming 3.Test the drain from the oil heater once fireroom, 'you should befully clothed. The each hour. valves, pipes and exposed metal in flrerooms are always hot and'will burn the flesh and leave a 4.Blow through the gage glasses once each scar. Not only should you keep your shirt on, watch. but you should also keep your shirt sleeves rolled down. Whenever you areassistingin 5.Poke through the burner drain holes lighting off or securing boilers, or just generally once each watch. working in the fireroom, pay strict attention to postedsafetyprecautionsandtothose 6. Wipe up spilled oil at once. -/-*/ 7 6 i` 70 Chapter 6BOILERS
Observe theallowing safetyprecautions 2.Remove atomizers from registers as soon when securing a boiler: as -possible after securing. 3.Close all openings to the furnace as soon 1.In shutting down a fireroom, do not as all atomizers have been extinguished. close the master oil valve until the fuel oil pump 4. Pump the water level to three-fourths is secured, glass on cutting out a boiler,
7 7
71 CHAPTER 7
STEAM TURBINES AND REDUCTIONGEARS
We have discussed the basic steam cycle and CLASSIFICATION OF TURBINES various turbine propulsion units. In this chapter we shall discuss the components insde the casing Turbines may be classified in four ways: of the turbines and reduction gears so that you 1.By the manner in which the steam causes will havea basic understanding of how the the turbine rotor to rotate. stored energy (heat) in steam is transformed into 2.By the type of staging and compounding the mechanical energy (work) of rotation. of steam pressure and velocity. 3.By the division of the steam flow. 4.By the direction of the steam flow. TURBINES
The development of steam power was built around the reciprocating engine; however, the earliest steam engine operated on the TURBINE prniciple. Almost 2,000 years as Hero, a Greek mathematician built a small steam turbine and demonstrated that steam power could be used to operateothermachinery(fig.7-1).Hero's turbine consisted of a hollow sphere which carried four bent nozzles. The sphere rotated freely on two tubes that carried steam from the boiler. Steam generated iu the boiler passed upward through the tubes and into the sphere and out through the nozzles. As the steam left the nozzles, the sphere rotated rapidly.
Down through the ages the turbine principle has been applied to many different types of machines. The water wheel that was used to operate the flour mills in colonial times, the common windmill used to oump water, and the two-bladed windmill Used to charge batteries are .all examples of the turbine principle. In these examples the power is derived from the effect of the wind or a stream of water on a set of blades attached to a wheel. Inthe steam turbine, steam under pressure serves the same purpose as 139.23 We %Lind or the flowing water in the other types. Figure 7- .Hero's steam Turbine.
72 78 ( Chapter 7STEAM TURBINES AND REDUCTION GEARS
Under each of these classifications, there are several types of turbines, some of which are described briefly in the following paragraphs.
pulse Turbines, The energy to rotate an impvilse turbine is derived from the kinetic energy of a steam jet or some other rapidly moving fluid. The term "impulse" means that the force which turns the turbine comes from the impact of the rapidly moving fluid. The toy pinwheel (figl 7-2) can be used to study some of the basic principles of turbines. When you blow on the rim of the wheel, it spins rapidly. The harder you blow, the faster itturns. The steam turbine operates on the same principle, except that instead of the air you were blowing, ituses the high pressure steam from the ship's boiler.
The impulse turbine consists essentially of a rotor or spindle mounted on a shaft that is free to rotate in a set of bearings. The outer rim of NOZZLE NO.4 the spindle carries a set of curved blades, and the whole assembly is enclosed in an airtight case. 33.46 Several nozzles directthe steam against the Figure 7-3.A simple impulse turbine. bladespd turn the spindle (fig. 7-3).
STEAM NOZZLES (hereafter referred to as its pressure is reduced, but its velocity is greatly nozzles or stationary blades) are connected to increased. The potential energy of the steam the line that carries high pressure steam from the under pressure is converted to kinetic energy in boiler. As the steam passes through each nozzle, the high-speed jets emerging from the nozzles. These jets are directed against the turbine blades and turnthe spindle. 'In other words, the velocity of the steam is reduced in passingover the blades, and some of its kinetic energy is transferred to the blades as a force to turn the spindle. The modern impulse turbine operates on the same general principle as the model just described, but it has many refinements.
COMPOUND TURBINES have several rows of revolving blades with stationary nozzlesor blades mounted between each row. As the steam passes throukh the first stage, it moves faster in the nozzles and slows down while going through the moving blades. The second set of nozzles speeds the steam up again, making additional 139.24 kinetic energy available for the secondrow of Figure 7-2.The toy pinwheel operates on the impulse moving blades. This sequence continues through turbine principle_ all of the successive stages until ate pressure is ,,)
3 79 FIREMAN
NOZZLE ------STEAM CHEST EXHAUST
ROTOR EQUALIZING HOLE KEY.
SHAFT SHAFT / // %ri/iirrr GLAND GLAND 1,0,10 smA----0
tFaaaan.t t0..1110,1
139.25 Figure 7-4.A velocity compounded impulse turbine 38.78X with a reduction gear. Figure 7-5.Impulse turbine.
reduced -tothepoint thatit would not be rings keep the steam from escaping through tie easible to take any more energy from it. shaft bearing. We shall discuss the reduction gear The velocity compound impulse turbine shown on the turbine in figure 7-4 later in the showin figure 7-4 has two rows of moving chapter. It consists of a pinion gear (attached to blades. Steain enters through the inlet, flows thc spindle shaft) an4a much larger bull gear. through the governor valve, and passes through Because of its larger diameter, the bull gear the stationary nozzles. The steam undergoes a rotates much more slowly than the high-speed large pressure drop and a large velocity increase turbine. out of the nozzles. The steam then enters the first row of moving (rotor) blades, attached to Impulse turbines are used in the Navy to the rotor where there is a deease in velocity. It drive the forced draft blowers and most of the then flows through the stationary blades or feed water and fuel pumps. They have few guide blades. There is neither a pressure drop moving parts, are lightweight, do not take up nor a velocity increase while the steam goes mucKace, andrun with very little vibration. through the stationary blades. The stationary blades, attached to the turbine casing, merely In an impulse turbine, a STAGE is defined as provide a place for the steam to reverse its flow one set of nozzles and the succeeding row or before it enters the next row of moving blades. rows of moving and fixed blades. Another way The steam then enters the second row of moving to define a stage is that is includes the nozzles blades where there is also a decrease in velocity. and blading in which only one pressure drop The velocity is so reduced that by the time tie takes place. (In an impulse turbine, remember, steam reaches the exhaust, molsk of the energy theonlypressuredrop takes piaci inthe has been used to turn the spindle. nozzles.Therefore,the number ofsetsof The shaft of the spindle revolves in bearings nozzles in an impulse turbineindicates the supported by the turbine casing. Carbon packing number of stages.)
74 s0 .1.1.11111111.1r11,11,..
Chapter 7STEAM TURBINES AND REDUCTION GEARS \
impulse stages in one casing. The casing .is internally-divided by diaphragms which contain nozzles so that the residual steam pressure of one stage is utilized in the following stage.. This typeofturbineisknownasa PRESSURE-COMPOUNDED IMPULSE TURBINE because a pressure drop occurs in each stage, as the steam expands through each setofnozzles.Figure7-7showsa ROTOR pressure-compounded impulse turbine with four EQUALIZING stages. HOLE SHAFT SHAFT GLAND GLAND Reaction Turbines /pr:, , ;., .10. ,,, / The ancient turbine built by Hero operated on the reaction principle. Hero's turbine was invented long before Newton's time, but it was a working model of Newton's third law of motion 1111It Which states: FOR EVERY! ACTION THERE MUST BE AN EQUAL AND OPPOSITE REACTION. On first thought, you may find it 38.79X difficult to accept this statement on its face Figure 7-6.Velocity-compounded impulse turbine. value.However, let us look at some more understandable samples of Newton's theory.
Figure7-5shows a SIMPLE IMPULSE If you set An electric fan off a roller skate, it TURBINE. This turbine has one stage, consisting will take off across the table (fig. 7-8). The fan of one set of nozzles and 6ne row of moving pushes the sir forwArd and sets tip a breeze blades mounted on the rotor. Simple impulse (velocity); the air is also puShing backward on turbines do not completely utilize the velocity the fan with an equal force, but in an opposite of the steam, and arethereforenot very direction. You enjoy- Th*1:k breeze that is blowing efficient. One way to increase the efficiency of a single-stage impulse turbine is to add another roerar even two more rows) of moving blades -to the rotor wheel. Figure 7-6 shows a turbine which has two rows of moving blades. This type turbineisa VELOCITY-COMPOUNDED IMPULSE TURBINE becausethelowered velocity of the steam leaving the first row of moving blades, is used in the second row of moving blades; and, if a third row iS added, the additionally lowered velocity of the steam is used again in the third row. The fixed blades, which are fastened to the casing rather than t the rotor, serve only to direct the steamfrom froAriQ l one row of moving blades to another.
Another way to increase the efficiency of an 38.80X impulse turbine is to arrange two or more simple Figure 7- 7. Pressure-compounded impulse turbine.
75 , it FIREMAN
that in an impulse turbine the nozzles increase the velocity of the steam and transform the potential energy of the steam under pressure Li into kinetic energy in the steam jet. A forward force must be applied to the steam to increase its velocity as it passes through the nozzle. From Newton's third lawoof motion you have seen that the steam"jet everts a force on the nozzle and an equal reactive force on the turbine blades in the opposite direction; this is the force that 139.26 chives the turbine. Figure 7-8.The reaction of the air on the bladg rolls the electric fan across the sable. In the reaction turbine, stationary blades attached to the turbine casing act as nozzles and- direct the steam to the moving blades. The moving blades are mounted on the rotor. Most reactionturbineshaveseveralstages,with alternate rows of stationary and moving nozzle blades.
The "kickback" or reaction force generated by the nozzle blades can be demonstrated by a toy balloon. Blow up the balloon and toss it into theair. The airwill rush out through the opening and the balloon will shoot off in the opposite direction (fig. 7-9).
YWheriyou fill the balloon with air, you have rtate,ntial energy in the increased air pressure inside. When you let the air escape it is speeded 139.27 up (velocity) as it passes out, through the small, Figure 7-9.A toy balloon demonstrates the opening; this represents a transformation from 7' "kickback" or reaction principle. potential to kinetic energy. The force applied to the air to speed it up is accompanied by a reaction in the opposite direction. This reactive from the front of the fan, but the breeze force propels the balloon forward through the produces an opposite force on the back side of air. the blades to move the fan backward. When yOu try to push a car, you may not You probably think that the force that know it but, you are pushing back with your makes the balloon move forward comps from, feet as hard as you are pushing forward with Ole jet of air blowing against the air in the room, your hands. Try it scimetime when you are but this is not so. It is the reaction of the force standing on an icy road. You will not be able to it talfes to increase the velocity (speed) of the air move the car . unless you Ikon dig in with your asitpapes out through the - opening. The feet to exert the backward force. With a little balloon would .travel even faster if'it were in a thought on your part you should be able to vacuum. Try it the next time you are near a come up with enough examples to prove to balloon. yourself that Newton's third law .of motion holds true under all clidumstances. .The reaction turbine (fig. 7-10) has tall the The reaction turbine uses the reaction of a advantages of the impulse'type turbine, plus a steam jet to drive the spindle. You have learned slc&ver operating 4speecl and greater efficiency. 9 76 8 2 Chapter 7STEAM TURBINES AND REDUCTION GEARS
The severalstages through which the steam compound the total pressure drop into as many passes gradually reduce the steam pressure until steps as there are rows of fixed and moving practically ,off of the energy has been converted blades. This pressure staging lowers the steam to power. When a reaction turbine is operated in velocity in each stage. conjunctionwith a condenser,. theexhaust pressure of the turbine is only a smAll fraction of CONSTRUCTION OF TURBINES thenormal atmospheric pressure. The steam gradually expandsas itpasses through the successive stages. Therefore, the length of the Other than the contrcls, similar turbine parts blades is increased in each succeeding stage to are found in both the impulse,and the reaction take care of the additional volume of steam turbines, slick! as foundations, casings, nozzles caused by this expansion. (or stationary blades), rotors, Movabli blades, bearings, shaft glands, and gland seals. Brkfly, let us compare- the impulse turbine and the reaction turbine. In the impulse turbine Foundations you learnedthatthe steam pressure drops ONLY in the nozzles. Turbine foundations arebuilt up from a structural foundation in the hull to provide a In the reaction turbine,-the steam pressure, rigid supporting base. All turbines are subjected drops 'successivelyineach row of blades to varying degrees of temperaturefrom that whether fixed or moving. The combination of a exiling during a secured condition tothat row of fixed blades and a row of moving blades existirg during full-power operation. Therefore, in these .turbines is sometimes referred to as a jtame means 'must be provided to allow for DOUBLE STAGE (alsoknown asasing expansion and contraction. REACTION STAGE). Normally., the after end of the turbine is turbines pressure Allreaction are firmlysecuredbyboltstothestructural '-ornpounded. The PRESSURE-COMPOUNDEb foundation. The bolts have shanIts which are REACTION TURBINE has alternate rowsr-or fitted to the exact size of the holes in which 'stages,offixedand moving blades, which they are placed. The tightfitthus prevents motion of any kind.
At the forward end of the turbine, there are LOW PRESSUR ELEMENT tw9 ways to give freedom of momement. Either ASTERN ELEMENT elongated bolthbles or grooved sliding seats are used so the forward ena bf jhe turbine can move fore and aft, as eithei expansion or c_9traction, respectively,yikes piaci.
Casings
Turbine -casings are generally constructed of cast carbon steel. However, for tukbines that use superheated steam with temperaWires of more than 65091Vonthe 'casings are generally cast or fabricated from carbon molybdenum steel or chromium molybdenum steel. Each casing has a 139.28X steamchesttoreceive j theincoiliiir high Figure 7-10.A low pressure Peaction turbine with pressure steam which it.delivers to the" first set' the upper half of the case removed. ar of rrozzles ots blades.
77 FIREMAN
Nozzles Movable Blades
The primary funs n of the, nozzles is to The blades are secured to the turbine casings convert thethermalenergy of steam into kinetic and rotors b' various methods. Some ¶f the energy. The secondary function of the nozzles is methodsofsecuringturbinebladingare to direct the steam against the blades. In most illustrated in figure 7-13, parts A through D. The modern turbines the Rozzles are made up into straightcircumferentialdovetail(part A). is groupsorblockswitheachgroupbeing primarily" usedtosecure rotor bladei. The controlled by a separate nozzle control valve. inverted circumferential dovetail (part B) is used The amount of steam delivered to eachstage'to secure blading in most impulse turbines. The thus becomes thefunction of each of the side-locking key piece method (part C), which is nozzles and nozzle control valves in eachgroup used only on casing blades, consists of drivinga or block. A diagrammatic arrangement ofa locking key piece between the blade root anda nozzle group is shown in figure 7-1-1. groove in the casing. The sawtooth serration method (part D) isused for both rotor and Rotors casing blades. Rotors (forged wheels and shaft) are Made of carbonsteelwhen usedwith:s)team of Bearings relatively low temperatures. Howev, when the temperature of the steam will be greater than Therotorofeveryturbinemustbe 650°F,therotorsaremadeofcarbon supported inbearings, which serve a (Jou* molybdenumof someuthercreep- resistant purpose. The bearings ( I) carry the weight of alloy.Inalltypes of turbines, the primary the rotor and (2) maintain the corsed radial purpose of the rotoristo carry- the moving clearance between rotor and casing. AU main blades which receive the energy from the steam turbines, and mostauxiliaryunits,havea to turn the turbine shaft. A rotor without the bearing at each end of the rotor. blades is shown in figure 7 -I 2. Bearings are generally classified as sliding surface (sleeve and thrust) or as rolling contact (antifriction). All propulsion and most auxiliary turbine
NOZZLE installations are equipped' with sleeve bearings, CONTROL VALVES whicharkoftwotypes:cylindricaland
+lb
0
-47.13X 47.15X Figure 7-11.Diagram of a nozzle group. Figure7-12.Turbine motor l4ithout tllades.
78 84 Chapter 7 STEAM TURBINES AND REDUCTION GEARS
BLADE BLADE
F ` WHEEL WHEEL
CAULKING PIECE
LABYRINTH SHROUDING LOCKING TURBINE CASING KEY CASING PIECE
ROTOR 77; 4f//4,>%
N.4 Figure 7-13.Methods of securing blading.
R 79
el FIREMAN
turbine, usually just forward of theforward esm turbine bearing. A thrust bearing is also installed on the propeller shaft either at the forward end UPPER HALF of the main reductionbull gear or in the propeller line shafting abaft (behind) thegear, to OUTLe TS, TO take the thrust of the propeller. Except that SIGHT FLOW AND the THenuomeren DAM propellerthrustbearingis' much larger, the DRAINS design of turbine thrust bearings and propeller thrust bearings Much thesame. Some thrust bearings are lubricated by thesane lubricating oil system which suptIliesoiltO-kthe turbine -- bearings and reduction `gears. Some )ships have separate thrust bearings aft of the reduction gear;this arrangement hasits own lube oil system. An assembled thrust bearing element is shown in figure 7-15. RollingContact(antifriction)bearings 98.3X include ball and roller bearings whichare used Figure 7-14. A typical propulsion turbine joumcl ott some small auxiliary units. bearing. Shaft Glands spherical-seated. A typical cylindrical journal Shaft glands are used to prevent leaking of bearing is shown in figuie 7-14. steam from the turbine casing atthe points THRUST BEARINGS take care ofany axial where the shaft extend through the casing. The thrust, which may exist in a turbine rotor,and shaft glands on auxiliary turbines. havea gland alsoholdtheturbinerotorwithincertain' housing which may be eithera part of the definiteaxialclearances. Thrust bearings are turbine casing or a separate housing bolted installed on all main turbines to on one end of the the,casing.Twotypesofpackingare
PACKING is STRIP OR FIN IA0)10104. I:.3 pi.. 1=7_ SHAFT
CARS PAOtI G CKING BLOCK It RING 10ola N r,...\. ....\ "'AO.. KEY
0 Mr= Ma= -01141°-
SHAFT
47.17X. 139.29X Figure 7- 16. Turbine motor shaft glands: Figure 7-15.Assembled thrust bearing element. A. Labyrinth packing gland; B. Carbon packing gland..
I 80 86 Chapter 7STEAM TURBINES AND REDUCTION GEARS
usedlabyrinth packing and carbon packing, GLANb SEALING STEAM which may be used either separately or in AT 2 poi combination. ; Labyrinth packing, shown in figure 7-16A, consists of rows of metallic strips or fins. The strips are so fastened to the gland liner that Ithere is a very small space between the strips and SHAFT the shaft. As the steam from the turbine casing leaksthrough the small space between the 47.10X packing strips and the shaft, steampressure is Figure 7-17.A turbine steam reading gland. gradually reduced.
1 Carbon packing rings, shown in figure 7-16B, (15to17 pounds absolute) to the turbine restrict the passage of steam along the shaft in sealing glands (fig. 7-17). In high-pressure and much the same manner as do the labyrinth cruising turbines at higher speeds, the pressure packingstrips.Carbonpackingtrigsare on the turbine end of the forward glands will be mounted around the shaft and held in place by so great that steam will bleed out through these springs. Three or four carbon rings are generally glands, automatically sealing them. Since these used in each gland. Each ring is fitted intoa glands may attimessealthemselves,itis separate compartment of the gland housing, and, necessary to have a separate system for the eachringconsists of two,three,orfour cruising and the high-pressure turbifies. segments which are butt-jointed to each other. These segments are held together by a garter spring. Keepers (lugs or stop pins) are used to REDUCTION GEARS prevent rotation of the carbon rings when the shafttrott--e(s.Theoutercarbonring InChapter4wediscutsedthemain compartleht is\connected to a drain line. propulsion locked-train type, double-reduction garing used in the DD-692 class destroyer. N,", Carbon packing is suitable only for relatively letusconsiderthe mainpropulsion, lowpr ssuresandtemperatures. Therefore, double-reduction gearing. when bath types of packing are used in one gland, thel labyrinth packing is used at the initial MAIN PROPULSION, high-pressure area and the carbon packing is DOUBLE-REDUCTION (1 GEARING used at the low pressure area. Thereare twoothertypesofmain propulsion, double-reduction gearing in usethe Gland Sealing System articulated gearing and the nested gearing.
Steam is passed into the glands to seal the Articulated Gearing glands of the turbines and to prevent air from The ARTICULATED GEARING, shown in being drawnintothecondenser.The figure7-18,. has more bearings and occupies low-p re turbine, which operates at all times more longitudinal space in a ship than the nested with a, va um in its casing, must have steam or locked-train type reduction gearing, shown in admitt at.11 times to the glands from some figure 7-1q.- This type is seldom used in the extern s ce.This steam isled from the Navy; it is nth * on combatant ships. auxiliaryxhaust line to pass through a cutout valve, n through a weight-loaded pressure Nested Gearing regulatingvalveto the 'turbine glands. The weight-loaded pressure regulating valve operates The nested gearing rig. 7-19) is the simplest at all times to maintain a pressure of 1/2 to 2 psi of all double-reduction gears. It uses eminimum
87 FIREMAN
1ST REDUCTION PINION
1ST REDUCTION GEAR
2ND REDUCTION PINION
DOUBLE HELICAL GEAR SINGLE HELICAL GEAR
MAIN GEAR
47.28 Figure 7-18.Articulated type of double gearing. INTERNAL SPUR GEAR EXTERNAL SPUR GEAR
2ND REDUCTION 2ND REDUCTION PINION PINION
1ST ' REDUCTION 1ST PINION amok: IT REDUCTION INION
1ST 1ST REDUCTION REDUCTION GE AR GE AR WORM GEAR Dt\IEL GEAR
/ND 5.22 2N D REDUCTION Figure 7-20.Types of gears found in shipboard REDUCTION , PINION PINION machinery.
2ND REDUCTION OR MAIN GEAR reduction gearing used fOr main 'provision. iigured7-20 Illustrates common forms of gears 47.29 used in shipboard machinery. Probably one of Figure 7-19.Nested type of double reduction gearing. the simplest types of reduction gearing is the worm gear shown in figure 7-20.
Worm Gear number of bearings aril flexible couplings. The nested gearing type is used on most auxiliary Watpj gears are used to transmit motion ships; it is NOT used on combatant ships. between shafts which. are at right angles to each The ge ritrg used in shipboard pumps and other. The worm gear consists of a cylinder with auxiliary IT achinery is not as complicated as the one or more threads (sing, doUble, triple) cut on
82 88 Chapter 7STEAM TURBINES AND REDUCTION GEARS
the outside like a screw. The worm wheel isa 3)The uppelipart of the gear casing is the gear with teeth cut on the outside rim to mesh main cover which is divided into two sections with the threads on the worm. with inspection ports so located that the teeth The worm gearingspeedsreduction. A of any pinion or gear can be examined without complete turn of the worm turns the wheel removingthemaincoversections.The ahead the distance of one tooth on the wheel. A inspection ports are covered with easily opened double thread worm will revolve the gear twice hinged covers. as fast as a single thread worm. Reduction gearing for pumps and other
auxiliarymachineryisconstructed, slightly REDUCTION differently than the main reduction gearing just GEAR CONSTRUCTION discussed. In the ship's service generator, the pinion is forged together with the shaft as one The gears in a main reduction gear uunit,sue.h whole part. One end 'of the pinion shaftis as the main gears,and the pinion gears, mustbe flanged and bolted rigidly to the- turbine shaft. capable of transmitting tremendous power loads. The gear wheel is pressed and keyed onto the The pinibn gear is the smaller of two meshing shaft.. . gears and is usedjnainly for decreasing speed In main circulating pumps the on is a and increasing power,.Since even a very slight solid forging, while the gear it cons 'd by unevenness of tooth contour and spacing will welding a forged hub and a forged rim ogether. cause the gears to operate noisily; or even fail, The gear hub is bolted to a plate which is keyed special precautions are taken manufacture the to the gear shaft,.) 4 gears to exactdimensions. Thehe gear§ are cut in a Thereddaicongearofa turbine-driven room maintained at constant teniperature and condensate pump, shown in figure 7-22, which is humidity to eliminate expansion, contraction, a worm shaft and a worm wheel, reduces the and oxidation of the metal. turbine spedof approximately 5500 rpm to Almost all pinion gears in mite reduction pump spe of approximately 1100 rpm. The gearing are machined completely of specially worm is cut in a solid, low-carbon, nickel-steel heat-treated, nickel-steel forgings.Generally, the ft. forging. The worm wheelis a solidnickel-bronze gear wheels are of built-up construction with the casting wliklf pressed onto a forged steel teeth cut in forged steel bands which are welded shaft. The gear casing is of cast steel to form to ste webs.bs. The firstreduction gears are rigid suppoit for the rotating e ents. It is split general!welded on theirrespective shafts. The horizontally for easy assemblor disigsembly. bull gear is usually pressed on the shaftagainst a locating shaft shoulder and is Secured by one or WHEEL ore keys and a locking nit mechanism (fig. 7-21). KEY SLOT LOCKING Gear casings can be divided into threemajor NUT KEY SHAFT parts:
. . , 1) lower part (basesection)supports tihebull`gear,gear,main thrust bearing, and the high-speed parts of the reduction gear. The lowerosection al-so serves as the sump or. storage tank for the lubricating oil in the system.
2) The intermediate section of the casing supportsthebearinghousing forthe 4 intermediate speed pinions and gears as well as 13.3'0 the high speed pinions. 1:' 89 Figure 7-21.--Key and !odd nut.
83 FIREMAN rs 2.ROLLINGFRICTIONbetweentwo solid objects, one (or both) of which is rolling on. the other. 3. FLUID FRICTIONbetweenthe, molecules or particles of a fluid, or between two films of fluid.
Sinceliquidlubricantscanbe -readily circulated, they are used universally for internal WORM a SPUR lubrication. REDUCTION GEAR Lubkicating oils are mineral oils obtained petroleum.Intheory,eluid lubrication is b ed on the alUal separation of the surfaces so that no metal-to-metal contact occurs. As long as an oil film remains unbroken, sliding or rolling friction is replaced by the fluid friction (internal friction) of the lubricant itself. TURBINE CASING Under such ideal conditions, friction and wear are held to a minimum.
41, Purpose of Lubrication -ccts The primary purpose of lubricating oil and PUMP SHAFT grease is to SUBSTITUTE FLUID FRICTION FOR EITHER SLIDING OR ROLLING FRICTION. This means thatalubricant of 47.38 sufficient quantity and consistency must be Figure 7-22.Main condensate pump roduction.bearing. provided to keep the moving metal parts (of bearing, lining, and journal, for example) from contacting eachother. The remaining fluid LUBRICATION friction, within the-lubricant itself, is far less than that which would otherwise occur between All moving ires receive a steady the solidobjects, but italso generates heat and adequate supply of oil of proper quality at which must be removed: the correct temperature. Impurities and foreign matter must be removed from the lubrication Thesecondary(buthighlyimportant) system and a reserve supply of good clean oil purpose of a lubricant is that of ABSORBING must be maintained. AND REMOVING THE HEAT whichis generated by the fluid ftion as well as the heat To understand the principles of lubrication, which, in steam turbine conducted along the you should know the purposes of a lubricant. shafting from the steam-h d rotors. Removal Lubricants reducefriction between moving of this heat by the lube oil prevents serious parts.Frictioriistheresistanceto -motion damage to the machinery parts and makes it between the two bodies in contact. When this necessary to have the oil repeatedly cooled as it frictional resistanceis overcome, and motion `circulates about the mechanisms takes place, heat is generated. There are three Ingeneral,BOTH FRICTION AND .kinds of friction: OPERATING TEMPERATURES inbearings . increase with a g.vater unit bearing pressurei, 1. SLIDIkG FRICTIONbetweentwo with thinner films b.f. the lubricant, if below a solid objects whose outer surfaces slide over definiteminimum; witha high velocity of each other. rubbing or rotation-of the journal; and with a
84 0' 90 Chapter 7STEAM TURBINES AND REDUCTION GEARS
BEARING some rotary water pumps are lubricated with a JOURNAL small amount of water that leads through the bearings and moisten the packing. OIL FILM Lubricating Systems
Each turbine is provided with a lubricating system that supplies oil under pressure to t bearings. The system consists a sump or reservoir for storing the oil, an oilpump, a strainer,a cooler, temperature and pressure gages, and the necessary piping to carry the oil to the bearings and back to thesump. The location and arrangement of these partsvary with each make and type of turbine. The lube oil pump is generally a gear-type pump. A definite pressure is maintained in the oilfeed lines. A pressure relief valve allows excess oil to recirculate back td the suction side of pump. Quite often dual strainers are connected in 47.78 the line so that the system can operate onone Figure 7-23.The oil film ceparates the rotating, strainer while the other one is being cleaned. shaft from the bearing. The tube-in-shell type of cooler is generally used with sea water, zirculating through the tubes and the oil flowing around them. The temperature of higherviscosityof the lubricant. (Viscosity the oil is controlled by adjusting the valve that refers to the flowing qualities of a liquid. Water regulatesthe amount of sea water flowing and gasoline or liquids which flow freely, have through the tubes. a low viscosity. Cold molasses and honey do not Oil flowfreely;therefore,theyhaveahigh mustcirculatethroughtheturbine viscosity.) bearingsoat the prescribed pressure and within certain 'temperaturelimits. A pressure gage installed in the feed and a. thermometer Bearing Lubrication installed in the return line indicate whether the oilsystemisfunctioningproperly. Most of the moving parts of a machine are Thermometers are often installed in the bearings supported in bearings that permit them to rotate to serve as a warning against overheating. If freely. Lubrication consists of supplying these thereis a decided drop in oil pressure, the bearings with oil. The oil forms a film on the engine should be shut down immediately; even surfaces of the shaft and the bearing, and keeps a moderate rise in the oil temperature should be them separated(fig.7-23). An oil must be investigated. An oil-level float gage indicates the selected that has enough body to keep the metal amount of oil in the sump. surfaces from touching eachther during ALL operating conditions. Lubricating Oil Bearingsthatcarryaheavyloadare and Greases sometimes lubricated Ailith grse. These bearings are equipped with standardease cups or zeric Many different kinds of lubricating materials fittings like those on an autmobile. The cups are in use, each of them filling the requirements must be kept filled at all ties. The shafts of of a particular set of conMons. Animal and
85 OP
FIREMAN vegetableoilsandevenwaterhavegood lubricating qualities, but they cannot withstand high temperatures. Mineral oils, Aimilar to the ails used in an automobile engin?", are the best typeoflubricantformodern machinery operating at high speeds and high temperatures. Some heavy-duty bearings are lubricated with grease in about the same way that the spring shackles andsteering gear of your carare greased.
Minerallubricatingoilsare derived from crude oilin the same process which produces gasoline,kerosene, and fueloil.They vary according to the type of crude oil and the refining methods used. The same type of oil is usually made in several grades or weights. These grades correspond to the different weights of oil for an automobile varying from light to heavy. Oils used in the Navy are divided into 9 classes, or series, depending on their use. Each type of oil has a symbol number that indicates itsclass and viscosity. For example, symbol 2190 oilisa number 2 class of oil with a viscosity of 190 Saybolt Seconds Universal. The viscosity number represents the time in seconds that is required for 60 cubic centimeters (dc) of WASHERS the oil, at a temperature of 130° F, to flow HEATING OIL ".NUT through a standard size opening in -a Saybolt VESSEL ORK viscosimeter (fig. 7-24). A 2190TEP oil is used for all propulsion 38.214 turbines and reduction gears. The letters TEP Figure 7- 24. Details of the viscosimster tube. indicate that the oil has been treated to give it water-protectingandcorrosion-resisting L.) properties, and extra load carrying capacity. The common SODA SOAP GREASES This oil is also used in the turbines that drive the used for applications where no water is prese t variou% kinds of pumps an blowers, except and where operating temperatures approach 20 those pumps that are driven through a worm F. The common LIME SOAP GREASES do n t gear which use a Navy symbol 3080 oil. absorb moisture or emulsify as readily as the soda soap greases, but have lower melting points. Lubricating greases are mixtures of soap and They are us-ed as general purpose greases for lubricating oil. Fillers, such as graphite, are also light load applications at ordinary operating, added to some greases to make the\ grease more temperatures.' These two types of greases will effective for certain lubrication requirements.. satisfactorilylubricatethe majorityof machinery. The soaps used on the common SOAP AND Certain lubricating greases containVitives. OIL GREASES are chemical compounds formed These SPECIAL ADDITIVE AREAS are byfats or fatty acids' reacting with various identified by the additn. For example, LEAD alkaline materials such as lime, soda, aluminum, OLEATE SOAP GREASES are used for certain zinc') barium, lithiumjead, and potassium. bearing surfaces which are so heavily loaded that
86 1,
- 92 e Chapter 7STEAM TURBINES AND REDUCTION GEARS ordinary greasewillnot maintain afilmto and the HARD GRADES are used at slow speeds preventcontactoftherubbingsurfaces. under heavy pressure. EXTREME PRESSURE GREASESalso incorporate special additive agents to provide Standard Navy Lubrication° necessary film strength. OXIDATION INHIBITOR GREASES have AlWays be surethat you areusing the an additiveincorporatedtoensurebetter specified lubricant for the individual machinery) stability at high temperatures and to prevent part,unit,orsystemyou areresponsible rusting under these conditions. In GRAPHITE for operating or maintaining. GREASES, the added graphite actsas a mild MostshipsmakeupLUBRICATING abrasive to help smooth roughened surfaces, and CHARTSforquickreferenceonthis acts as a Her to smooth over unequal surface information. These charts generally Containa spots. It also substitutes its own low friction for line diagram of the unit or system, point of that of the metal it covers; this is especially lubrication, symbol of lubricant, quantity, Ind importantwhereabearingis exposedto interval of supplyalong with applicable general temperatures so high that ordinary grease or oil instructions,operatinghints,andpossible wouldbreak' dOwn. Exceptforsuchhigh casualties. The charts are generally posted in 1(-- temperatures, .`gr4hite grease should not be used machinery compartments. in bearings which are in first-class condition. The manufacturer'stechnical manual for each- unit of machinery is the basic reference for -Each of thscs several types ofgreasesis the correct lube oil,if no lubrication chart suppliedin three grades:soft, medium, and (basedonmanufacturer'sinstructions) is hard. SOFT GRADES are used at high speed available. In addition,theTABLE OF under ight pressure; the MEDIUM GRADESare RECOMMENDED OILS can be found in chapter used at medium speeds under medium pressure; 9450 ofNavShips Technical Manual
93
87 .
4, CHAPTER 6
AUXILIARY'MACHINERY AND EQUIPMENT In addition to the propiiIiittiLmachinery and steam-jet refrigeration system and the vapor equipment, you will become acquainted with compression cyclerefrigerationsystem. The other types of machinery, such as refrigeration steam-jet system is used on some naval ships for equipment,airconditioning equipment and air conditioning and on some merchant ships for distillingplants.Youwillalsobecome large area, moderate temperature refrigeration. acquainted with the steering gear, the anchor The steam-jet plant (fig. 8-1) consists of a flash windlass and capstan, lube oil purifier, undry tank, a booster ejecta, a condenser,, air ejectors, eotOpment, galley equipmeht, air compre rs, and the necessary pumps. and piping. 'The flash orafies, elevators, and 'winches. The information tank(sometimescalledthe, evaporator)is provided inthis chapter will be general in maintained unde /exceptionally high vacuum by nature; primarily, we shall discuss the location a steam-jet boo ter ejector as water is sprayed and the function of the auxiliary machinery and into the flash tank, part of each drop flashes equipment mentioned above. into vapor and thereby cools the unvaporized portion of each drop to approximately 50°F, or lower depending on t.Itcapacity of the unit. ° REFRIGERATION EQUIPM The cooled water o thethe bottom of the
sh , then pumped to the cooling coils and There are two basic types of mechanical r rned to the flash tank at a temperature of refrigeration systems used in the Navy, the a proximately 55°F.
J AIR. EJECTORS BOOSTER EJECTOR AUTOMATIC VALVE AND -0- STEAM LINES STEAM CONTROLS VENT STEAM
1ST LINE STAGE
COOLING ..11 r 1 WATER 213" V U 1., FLASH TANK k COOLING 2Y' VACUUM SALT WATER ..,e,...-4-SPRAY PIPES4..
AFTER ...... **_,.""_ ./*". INTER %. "L >,, CONDENSER CONDENSER CONDENSER *> k ki ORA N TO =4:CHILLED AAP) SHIP'S SYSTEM DRAINTO WATER ----r=" WATERLdvEL CONDENSER CONTROLLER PUMP.. PUMP 4
CONDENSATE TO RECIRCULATING LINE AND SHIP'S DRAIN SYSTEM CHU.LEDATER SYSTEM
47.89 Figure 8-9. Steam -jet refrigeration systeip.
88 -94 Chapter 8 AUXILIARY MACHINERY AND EQUIPMENT
COMPRESSOR EVAPORATOR The self-contained units, which have the 123 VAPOR refriirration source within the unit cabinet, REIRIORANT inchlae d .1=3 MOD king water coolers, refrigerators, and REFRIGRANT frozenod cabinets. +1ST FLOW Other refrigeration equipment includes two types of ice-making machines. One type is a self-contained unit which makes ice cubes: The CORADiSER other is a tank-type which m*.rs large slabs of ice. The tank-type ice mac T. is normally located in a separate machinery room which is identified as the ice machine room. This type is installed on auxiliary ships such as tenders and SEA repair ships. RECEIVER WATER 47.90 Figure 8-2.Vapor compression (R -12) cycle AIR CONDITIONING refrigeration. EQUIPMENT Air conditioning is installed on naval ships ,- The vapor compression cycle refrigeration for Certain spaces where personnel efficiency, sys m (fig.8-2)is most commonly used on health, safety, or operation of equipmentmay navalshipsinvarious applications, such as be endangered by high temperaturesor high refrigerated6hip's stores, refrigerated cargo, and humidity. rz unitary (self-contained) refrigeration (as ship's service store equipment). Some of the spaces thatmight be air Ship's stores spaces are refrigerated for the conditioned include the radio and radar control preservation of food supplies. The insulated spaces, sick-pay areas; and living and berthing compartments for cold storage spaces are the spaces. The radio and radar control spaces are walk-in type. The equipment selected to cool usually air conditioned because& the high heat given off by the equipment. This heat, especially thesespacesisdesigned to maintain certain temperatures: for ships designed before 1950, in combination with high humidity, lobe the meat room at15°F, fruit and vegetable dangerdus to the operator and the equipAlt. Air conditionedsick-bayareas haVe proven rooms at 40°F, butter and egg rooms at 32°F; advantageous" in and for ships designed since 1950, the freeze thattheyhelptospeed room at 0°F and the chill room, at 33°F. recovery. The living and berthing spaces are often air conditioned, both to provide comfort Auxiliaryshipshaverefrigeratedcargo forthecrewandtoincreasepersonnel spaces for stowage of perishable food that is efficiency. intended for the forces afloat and for advanced bases. Approximately 30 to 60 percent of the There are two basic types of-air conditioning refrigerated cargo space is maintained at 0°F (at equipment used aboard ship. One typeuses -5°Fonthelatestdesignedships).The chilled water for the cooling medium; theother remainder of the refrigerated area is maintained uses refrigerant R-12 to carry away the heat. at 33°F to 35°F. Most of the air conditioning equipment aboard Unitary refrigeration systems are of two Navy ships uses the.refrigeration equipment for typesremote and self-contained. The remote the removal of heat from the circulatingwater type is a complete unit except that the source of or refrigerant. *Heat is removed by the cooling refrigeration is lOcated separately and is not coils of the refrigerationequipment. There are contained within the unit cabinet. Equipment of also some (smaller selfzcontainedunits used thiS,type includes soda fountains and ice cream aboard ship similar to the window type used in hardening machines. homes.
89 - FIREMAN
FIRST-EFFECT SECOND-EFFECT DISTILLING SEPARATOR SEPARATOR CONDENSER
VAPOR FEED HEATER
SECOND-EFFECT O TUBES
FIRST-EFFECT FLASH TUBES CHAMBER
BRINE PUMP SUCTION
'FIRST-EFFECT SECOND-EFFECT DRAIN REGULATOR DIVISION PLATE DRAIN REGULATOR
47.117 Figure 8-3.Soloshell doubfa-effect distilling plant.
DISTILLING PLANTS Steam operated distilling plants re classified as coil, submerged, tube, vertical basket, and The two basic types of distilling- plants flash types. The coil type is found on a res q igialledaboard navalships are the vapor older auxiliaries, while the submerged tube type compress '-distillingplant and e 'beam is found on most older sh,ipsahe vertical basket - dis v. plant. The main difference bet n the and flash types are newei'designs and have been two ty es of distilling plants is in theethod installed on some combatant ships constructed used t e apply heat to the sea water., In the vapor in the last 15 years. Some submerged tube types oompreonplant,thesourceof heatis were also installed during thkperied. obtainedom electrical energy. In the vertical basket type low-pressure The vapor compression type distilling plant steam flows into a corrugated basket that is was first developed primarily for -submarine surrounded by sea water. Sere the steam giveS' ,service, where the absence of steam made it up its heat to boil the .sea; water and is then necessary to supply anotfier form of heat condensed. The fresh water vapor from the ,nergy. However,- on newer type submarines, boiling sea water is condensed and then removed this type plant is currently u ed for back-up as distillate (fresh water). only. It is also used on older, sm iesel-driven surfacece craft where the daily dem d for fresh In ,the flash` type, preheated feed water is war does not exceed 4,000 gallons per day discharged into a vacuum chamber where a (gpct). The vapor compression consists of three Aim of the water is vaporized (flashes into main componentsevaporator, compresior, ste ).The remaining water passes into a heat exchanger. . econd flash chamber where further vaporization Chapter tj--UXILIARY MACHINERY ANDEQUIPMENT
takes ace. Any number of flash chambers, are of the soloshell double-effect type. This typo where liporization takes place,can be installed. consists of a single shell that hasa vertical Each sta e has a condenser in which thefresh partition which divides theshellinto two water vapor is condensed. evaporator shells. Therearethreebasictyposdf One type of 20,000 gpd caOcity, soloshell submerged -tube type distilling plants: soloshell dooiote-effect plant is installedon some of the double-effect (fig. 8-3), the Viple-effect, andthe older ships. Where itis necessary to furnish two-shell double- effect. The principal difference 40,000 gpd, two such plantsare installed. Some between the triple-effect plant and the two-shell older destroyers are equipped with twosoloshell double-effedt plant is the number ofstages of cvrorator plantsone, located in the forward evaporation.Inthedouble-effectplant mien oom with a capacity ofapproximately evaporation takes place in-two stages, while in 12,000 gpd; theother,locatedin the aft the triple-effect plant.evaporation takes placein engineroom, with a capacity of approximately three stages. 4,000 gpd. Themost commonly used20,000 gpd two-shell double-effect plant is built withtwo hotizontal 'cylinder evaporator shellsmounted STEERING GEARS parallel to each other. The triple-effectdistilling plantis similar to the two-shell double-effect Therearetwobasictypes of steering plant except that the triple-effect planthas an mechanisms in use in the Navy. Oneis the intermediateevaporatingstage.A standard electromechanical steering gear, used extensively triple-effect, 20,000 gpd plant is illustratedin on small noncombatant ships. The other, and figure .84. most common, type is the electrohydraulic steering gear. In the electromechanicalsteering Almbst all low-pressure distilling platsup gear, an electric motor is the primemover. The and including the 12,000 gpd capacity plant electric motor receives 1 a signal from the bridge
2nd EFEECT FEEDHEATER err AIR EJECTOR" E FEED CHEAT CONDENSER VAPOR OU AUXILIARY STEAM INLET CONDENSATE COOLER
DRAIN CONNECTIONS BRINE P SUCTION 2nd 'OHO 3rd EFFECT
47.118.1 Figuro 04.-20,000 gpd triplo-affact distilling plant.
91 97 FIREMAN and, through shafting and a gear arrangement, principles are basically the same. Some ships. moves the rudder. havedoublehydraulicrams andcylinders mounted fore and aft, as shown in figure 8-5, Intheelectrohydraulicsteeringgear, while other ships employ a double cylinder, movement of therudderisobtained from single-ram, mounted athwartships. A typical hydraulic rams operating in cylinders that are single-ramelectrohydraulicsteeringgearis connectedtovariabledeliverypumps. illustrated in figure 8-6. Development of this type was prompted by the large electrical power requirement necessary to Emergency steering gear is provided on all steerships of largedisplacement and high combatant and auxiliary naval ships that have speeds. electrohydraulic steering gear. Generally, large The electrohydraulic steering gear provides combatant ships have a duplicate hydraulic same udistinctadvantagesoverthe steering gear for emergency use. On other ships electromechanical steering gear: the emergency gear consists of a hand-operated hydraulic pump. I.Little friction between moving parts 2.Immediate responses to movement of the steering wheel ANCHOR WIND LASS AND CAPSTAN 3.Requires small deck space and head room A windlass is a piece of deck machinery used 4.Savings in weight primarilyforpaying-out andheaving-inan 5.Flexibility and dependability. anchor chain. A wildcat (drum), fitted with whelps to engage the anchor chain may be There are various types of electrohydraulic mounted eit'her vertically or horizontally at the steeringgearsinuse,buttheiroperating end of the windlass shaft. (A whelpany one of
TOLE PUMP CYLINDER IOLE MOT YOKE CYLINOE
SHAFTS SIX-WAY PUMP 0 TRANSFER COC TR"!AXES 'NG
RuODER CTLINOEN RUNNING 41 014111 66666 PUMP RACK AND PINION
ELECTRIC LEADS FROM STEERING STAND N.{ B SUPPLY NIRETURN SELL SYNCHRONOUS PLANETARY nEcEIYEH DIFFERENTIAL GEAR 4 47.139X Figure 8-5.Diagrammatic arrangement of a double-rem electrohydraulic steering gear.
92 98.7 .1
Chapter 8kUIC MARY MACHINERY ANDEQUIPMENT
the ribs or ridges on the drum ofa windlass. It Some) older naval shipsare equipped with a looks much likaD the sprocket wheelo a chain geared windlass driven by a steam engine fall.) or an electricmotor. Some ofthenew smaller General requirements of the anchor windlass combatantshipssuchasdestroyersand are that it must be simple, rugged, and reliable. destroyer escorts are equipped with the electric motor type. Figure 8-8 It must be capable of reversal and havesuitable I)lustrates an electric brakes. windlass for a modern destoyer.
There *ethree'generaltypesof A capstanisaspool-shaped,vertically power-drivenanchorwindlasses: Mounted drum used for heaving-inon heavy electrohydraulic,electric,andsteam. mooring lines. Figure 8-9 showsa vertical shaft Hand-operated windlasses areused on small anchor windlass capstan which is normaltopside ships where the weight of the anchorgear can be equipment on a destroyer. Thecapstanis a handled without excessive effort by operating component part -of the anchor windlass,as personnel. shown in figure 8-7 and figure 8-8.
Tjae electrohydraulic anchor windlassesare advantageous where the load varies througha LUBE OIL PURIFIERS wide range because of the amount of anchor chain payed out, the force of the wind, the Purifiers,normallylocated inthe strength of the tide, and thetype of bottom in engineroom, are used to free contaminated which the anchor is set. Figure 8-7 illustrates lube a oil or diesel oil of water, sediment, andthe other typicalelectrohydraulicanchorwindlass impurities.The purifiersused arrangement. inthe) Navy operate on the principle of centrifugalforce;
STEEIONO WHEEL AUTOMATIC BYPASS ON AFTER COO( HOUSE nileiTcs", ELECTRIC CONTROLI (f*I0 SYSTEM TRANSMITTER UNIT TRANSMITTER PORT PORT CvlOADIR POST OR SPED CARL TRANSFER SWITCH CRANK FOR HANG OPERATION OF PORT PUMP
RUNPONG PUMP I, AFTER 1, ECK
STARDOARD oi,?tal CARLE CROSSHEAD TRANSFER SWITCH TRANSMITS CURRENT THROUGH EITHER PLUNGER CARLE OR TRANSMITTER (RAW POLL OTUP TO RECEIVER AS WOW INAPT TRICK WHEEL FOR HAND CONTROL UNIVERSAL JOINT
RICO MINDER MU PUMP WORM IDLE ELECTRIC WORM WHEEL MOTOR STARBOARD sum v Aram, SPIRAL GEARS
AUTOMATIC RFPAIS
27.83X Figure 8-6.Diagram of typical single-ram electrohydraulicsteering gear system.
-- 9 9 *\ FIREMAN
CONTROL STAND INDICATOR WILOCAT CAPSTAM 4EAO BRAKE OANO NANO OPERATED CHAIN PIPE
WEATHER OECK OECK CONTROL EXPANSION FOR TILTING BOX GAGE GLASS TANK OR FLOATING RING
AIR ESCAPE PRESSURE HYORAULIC COCKS GAGE HANO WHEEL FOR MOICATOR LOCAL CONTROL
INOENT ANO SPRING RELIEF VALVE LOA0E0 PAWL 3 WA' COCK
REOUCTION LOCKING GEARS HE AO MOTOR H YOR AUL IC MOTOR B-ENO
TO STVO WINOLASS MAGNETIC SAME AS PORT DRAKE PINION GEAR A -ENO VARIABLE MAIN OECK STROKE PUMPS COUPLING SECTION THROUGH PORT WINOLASS
Figura 8-7.Typical olectrohydraulic anchor windlass arrangement. 47.143X
LI that is, a bowl or hollow cylinder is revolved at higli speeds while contaminated oilis passed DECK 77... through it.Thisprocedureseparatesthe
ice11 impurities from the oil. There are two types of Nr purifiers, the tubular type and the disk types 7:71.11.4.4 FRICTION DRAKE The hollowcylinder ortubular typeis 12-i"r relatively small in diameter and is operated at LOCKING IIANDWHEEL highspeed. The cylinderisfittedwith a three-wing device that keeps the liquid rotating ) at the speed of the bowl without slippage. Figure 8-10 shows the tubular type purifier. The disk type purifier has a bowl of larger DRIVE diametei, which is fitted with a series of disks MOTOR that separatetheliquid into thin layers. A se nal view of a disk type purifier is shown in figu re 8-1 1. -;`44. ;I I rtgl,lilw lbw TIIIIPIIIIIIIIIIIIIIIfp AIR COMPRESSORS MOTOR OPERATED BRAKE There are many uses for compressed air aboard ship and it would be difficult to mention Figure 8-8.Electric windlass. 3.224k all of them. Some of the more common uses
94 10 Chapter 8AUXILIARY MACHINERY AND EQUIPMENT
include: operating pneumatic tools; ejecting gas Air compressors may be of the centrifugal, from ship's guns; starting diesel engines; charging rotary, or reciprocating type. The type used is andfiringtorpedoes;operatinggun determined by the volume and pressure of air co un terrecoilmechanisms;andoperating desired. Most of the compressors used in the automaticcombustioncontrolsystems. Navy are of the reciprocating type. Compressedairissuppliedtothe various Compressors are driven by electric motors, sigNrns by, high-pressure, medium-pressure,or internal combustion engines, steam turbines, or low-pressureair compressors, as appropriate. reciprocating steam engines. The air compressors Reducing valves reduce a higher pressure to a used most in the Navy are driven by electric lower pressure for a specific system. motors. Air compressors are classified in a number of Low-pressure compressors are those which ways.A compressormay besingle-acting have a discharge pressure of 150 psi or less. (compression on oneendofthestroke)(, Medium-pressure compressors are those which double-acting (compression on each end of the have a discharge pressure of 151 psi to 1000 psi. stroke); single-stage (one cylinder); multistage Compressors which have a discharge pressure (more than one cylinder); and the compressor above 1000 psi are classified as high-pressure air design may be such .that the pistons operate compressors. horizontally,vertically,oratanangle. Compressors are also classified according to the type of compressing element; the source of CRANES driving power; the method by which the driving unitis connected to the compressor; and 'the Cranes are designed to raise a load, lower it, pressure that is developed. and move it in horizontal directions. You will
r`1
I
flo
941Airaini- .-4
47.146 Figure 8-9.Vertical shaft anchor windlass capstan head.
ra 95 FIREMAN
IBELT GUARD
I MOTOR PULLEY I
COUPLING NUT
PURIFIED OIL OUTLET
I FUNNEL COVER
LOWER COVER I
47.86 Figure 8-10.Tubular type centrifugal purifier (Sharpies). find cranes installed on carriers, cruisers, and Detailed information concerning shipboard auxiliaries.Cranesareusedforhandling cranescanbeobtainedfromapplicable airplanes, boats, bombs, torpedoes, mines, sweep manufacturers' technical manuals. gear,missiles,trucksandstores.Some submarines are also equipped with cranes for ELEVATORS handling missiles. In general, cranes may be electrically-driverf, Manyavy ships are equipped with elevators engine-driven,orhand-driven.Cranes whichareused tohandle bombs, airplanes, constructed for very heavy loads (lifting heavy freight, torpedoes, and ammunition. Shipboard aircraft,boats,ortorpedoes)areusually elevatorsaredividedintotwogeneral _di electrohydraulic. classeselectrohydraulic andsplectromechanical.
9,6 102 et 4 Chapter 8AUXILIARY MACHINERY AND EQUIPMENT,
ELECTROHYDRAULIC ELEVATORS are Special control valves, located in thepressure dividedintotwo general typesthe direct and exhaust lines, regulate elevator speeds by plunger lift and the plunger-actuated cable lift. varying the amount of hydraulic oil admittedto, The platform of the DIRECT PLUNGER or discharged from, the rams. Mechanical locks LIFT ELEVATOR is raised or lowered byone allow the platform to be locked and held in or more hydraulic rams, which are located under position at deck level. Automatic quick-closing the platform. During the hoisting ofa platform, valves in the oil line prevent an unrestricted fall hydraulic oil is pumped into theram from a of the elevator. high-pressuretank (approximately 950 psi). TheplatformofthePLUNGER- Lowering of the platformisperformed by ACTUATED CABLE LIFT ELEVATORis discharging theoilfrom the rams intoa raised by wire rope fastened to the platformat low- pressure t ank, whichisunderan either two or four joints. Most hydraulic approximate pressure of 230 psi. airplane elevators are of this type. The wire Pressure is maintained in the high-pressure ropes in an airplaneelevatorare operated tank' by two hydraulic pumps (variable stroke), through a series of pulleys bya horizontal which take suction from the low-pressure tanks. hydraulic ram located below the hangar deck.
COVER CLAMP HOOK INLET ARM LARGE SPRING REGULATING TUBE
COVER CLAMP SPRING COVER TOP LONG COVER CLAMP COVER TOP SCREW INLET ARM SEAL RING COVER CLAMP NUT
SPRING SIDE FRAME COVER BALL CHECK SPRING HOPPER BALL CHECK VALVE
VALVE STOP SCREW
SHORT COVER CLAMP
SEAL RING
BRAKE
BOWL CLUTCH BLOCK SPACER FRICTION RING STUD WORM WHEEL FRICTION HUB TOP BEARING OIL FILLER CA
FRAME .
BOWL SPINDLE
BOTTOM SCREW
47.83 Figure 8-11.Dish type centrifugal purifiers.
97 103 FIREMAN
Special safety devices engate the" guide rails of to start and run on high speed. Low speed is theelevato , stopthefall,and holdthe used for automatic deceleration as the elevator platform IAen one group of wire ropes fails. approaches the selectedlevel. The platform ELE ROMECHANICAL ELEVATORS are travels on two or four guides. Hand-operated or used for freight, bombs, and stores. In elevators power-operatedlockbars,equippedwith of this type, the platform is raised and lowered electrical interlocks, hold the platform in the by one or more wire ropes which pass over stowed position or accurately hold the platform pulleys and wind or unwind on hoisting drums. when on- or off-loading tracks are used. Hoisting drums are driven through a reduction gear unit by an electric motor. An electric brake WINCHES stops and holds the platform. The motor has two speeds (full speed and low, or one-sixth A winch is a piece of deek machinery that, speed). Control arrangements allow the elevator has a drum or drums on a horizontal shaft for
DRUM REDUCTION ROPE CLUTCH DRIVE DRUM GYPSY GEAR GEARING GUARD LEVER MOTOR BRAKE SPEED D OIL LEVER BEDPLATE DRUM DRUM CONTROL BATH DRUM BRAKE CLUTCH. ELECTRIC BRAKE
80.149 Figure 8-12.Units of an electromechanical winch.
104 Chapter 8AUXILIARO MACHINERY AND EQUIPMENT
handling loads with wire rope. In addition, cargo The laundry equipment in a modem ship's winches may be equipped with one or two gypsy laundryconsists'ofwasher-extractor heads fitted for handling manila rope. Figure conalt*tions, dryers, various types of ironing 8- 1 7 illustra .s the units of an electromechanical and `pressingequipment,plusnumerous winch. miscellaneous items Such as laundry marking Winches are of the steam, electromechanical, machines. or electrohydriAc types. Winches handle wire rope used wail equipment such as booms and davits for handling boats and cargo; for fueling GALLEY EQUIPMENT and replenishment at sea; and for miscellaneous operations when the handling of rope under The food preparation and service equipment tension is required. located in the galley and messingspaces aboard Steam winches are normally installed on naval ships is designed for quantity food service. such, ships as tankers, where use in the vicinity Galley equipment is used for the cooking of flammable materials is required. Other older and preparation of food for use in the-general type auxiliary ships, which have direct-current mess. This equipment consists of ranges, ovens, power supplies, use electromechanical winches griddles, deep-fat fryers, mixing machines, meat where d-c motors provide the desired speed slicing machine, cube steak machine, coffee control of the winch drum or gypsy head. Since urns,toasters, .steam jacketedkettles,steam )newer auxiliary ships and all combatant ships do tables, scales, refrigerators, cooking utensils, and not have direct-current power supplies, they are dishwashing machine. Other equipment that are equipped with electrohydraulic winches. In an used specifically for vegetable preparation are electrohydraulic winch, the stroke adjustment of the machine-driven potato peelers, food cutters, the hydraulic pump provides the desired speed and the french-fry cutters. _Normally, the latter control of the drum and the gypsy head. threeypieces of equipment are located in a vegetable preparation room. On large ships such as carriers, tenders, and LAUNDRY EQUIPMENT repair ships, there is also a meat cutting room (butcher shop) where meats, fish, and poultry Prior to 1914, personnel aboard naval ships 'Arel, preparedforcooking.The equipment washe d'. their laundry by hand. Their equiptvent nqrAallyfoundinthisareaconsistsof consisted of a bucket, soap, and water. Today meat-cutting blocks,meat-grinding machines, most all naval ships are equipped with laundry power-drivenmeat-cuttingbandsaw,slicing facilities. Carriers, tenders, and repair ships also machines, knives and other meat cutting tools, have drycleaning equipment. and hooks for hanging meat.
105 99 CHAPTER 9
INSTRUMENTS
Measurement, in a very real '''sense,is the PRESSURE GAGES language of engineers. The shipboard engineering plant has many instruments that indicate to Pressure gages include a variety of Bourdon operating personnel conditions existing within a tube gages, bellows and diaphragm gages, and piece of machinery or a system. By proper manometers. The Bourdontubegagesare interpretationofthereadingsofthe generally usedfor measuring pressure of 15 instruments, operating pea nel can determine pounds per square inch (psi) and above. The whether themachine , orthesystem,is bellows and diaphragm gages and manometers operating within the pr- ed range. are generally used for measuring pressures below 15 psi. Recorded instrument readings are used to ensure that the plant is operating properly and BOUkDON TUBE GAGES also to determine the operating efficiency of the plant. The instruments provide information for The most common Bourdon tube gages used hourly, daily, and weekly entries for station in the Navy are the (1) simplex, (2) vacuum, (3) operating records and reports. The data entered compound, and (4) duplex gages. They operate /in the records and reports must be accurate since on the principle that pressure'' n 'a curved tube the engineer officer studies the records and has a tendency to straighten o t the tube. The reports to keep up with the condition of the tube is made of bronze for pres ures under 200 plant. Remember that accurate data entered on psi and of steel for pressures over 00 psi. the records and reports can be obtained only by Figure 9-1 shows a Bourdon t be installed in reading the instruments carefully. a gagekase. The Bourdon tube is the shape of a C andiswelded or sliver-bzed to the Theinstruments,indicators,and alarms stationary base. The free and othe tube is discussed in this chapter are included not only connected to the indicating mechanism by a because of theirrelative importance inthe linkage assembly. The threaded socket, welded engineering plant, but also to give you an idea of totheitationarybase, isthepressute thewideraigeandtypeofinstruments, connection. When pressure enters the Boadon - indicators, and alarms thatare used in the tube, thg tube straightens out slightly and moves engineering plant aboard a naval ship. the link connected with the toothed-gear sector. The teeth on the gear sector mesh with a small Engineering measuring instruments maybe gear on the pinion to which the pointer is classified into the following groups: attached. Thus when pressureinthetube increases, the gear mechanism pulls the pointer 1.Pressure gages around the dial and registers the amount of 2.Thermomete d pyrometers pressure being exerted in the tube. 3.Liquid levendica The simplex gage, shown in figure 9-2, may 4.Fluid flow ters be used for measuring the pressure of steam, air, 5.Revolutio nters and indicators. water, oil, and similar fluids or gases.
100 108 Chapter 9 INSTRUMENTS
The Bourdon tube vacuum gage, commonly TOOTHED GEAR SECTOR CASL used on auxiliary condensers to indicate vacuum OVAL SHAPED SEALED ENO in inches of mercury, is illustrated in figure 9-3. BOURDON T E CONNECTING Vacuum g ag e s indicate pressurdp below HAIR SPRING LINK atrrfbspheric pressure, whereas pressure gages indicate pressure above atmospheric pressure.
The compound Bourdon tube gage (fig. 9-4) usesasingleBoiudon tube of such great elasticity that it can measure vacuum (in inches) to the left of the zero point and pressure (in pounds per square inch (psi)) to the right of the zero point.
The duplex Bourdon tube gage illustrated in figure 9-5 has two separate gear mechanisms CONN CLING within the same case. A pointer is connected to LINK SCREWS MOVEMENT the gear mechanism of each tube. Each pointer SUPPORT PIVOT PINION operates independently of the other pointer. BUSHING SEALED END Duplex gages are commonly usedfor such THREADED SOCKET (PRESSURE CONNECTION) purposes as slVwing the pressure drop between STATIONARY BASE the inlet side and the outlet side of lube oil strainers. If the pressure reading for the inlet 38.211AX side of the strainer is much greater than the Figure 9-1.Bourdon tube installed in a gage case.
RFD HAND POINTER
II
38.211BX 38.211DX Figure 9- 2. Simplex Bourdon tube pressure gage. Figure 9-3.--Bourdon tube vacuum gage.
101 107 FIREMAN(
f:)' 61.3BX Figure 9-6.Indicating mechanism of a bellows 38.211EX pressure gage. Figure 9-4.Compound Bourdon tuke gage.
125 150 us
100
75 225 250 SO
25 300 CALIBRATING SPRING ZERO ADJUSTING SPRING
PANEL.OR BULKHEAD ZERO ADJUSTING SCREW
38.211FX 43 4 38.212X Figure 9-5.Duplex Bourdon tube gage. 108 Figure 9-7.Diaphragm air pressure gage. 102 a 14
Chapter 9INSTRUMENTS
pressure reading for the outlet side, the strainer MANOMETERS is most likely very dirty and is thus restricting' the flow of tube oil through the strainer. A manometer is perhaps the most accurate, least expensive, and simplest instrument for measuringlowpressup,orlowpressure 'BELLOWS GAGES differentials. A manometer, in its simplest form consists of a glass U-tube of uniform diameter, A bellows gage is generally used to measure filled with a liquid. The most common liquids pressures less than15psi. Some types are used are water, oil, and mercuryt One end of the satisfactory for measuring draft pressures and U-tube is open to the atmosphere and the ether for general low pressure measurements. The endisconnected withthepressure to be bellows' of t gage is made of stainless steel, measured. brass, ) be um-pper,Monol orphosphor Manometers are available in many different brow". A bellows 's shown in a gage case in sizes and designs. They all operate on the same figure'9-6. principle. Two common types of manometers are shown in figure,9-8i When pressure increases in the line to a bellows gage, the bellows increases in length and operates a"system of gears and lever which are THERMOMETERS AND PYROMETERS 10, connected to the ,pointer. The pointer then ,registers the higher reading on the dial. When the o 1-k thermometerisaprinstrumentwhich pressuretothe bellows gage decreases,the measurestemperature.Thetemperature bellows returns to its normal length, returning the pointer toward zero. When the pressure to thebellows iscompletely yremoved,the hairspring of %e spoVer returns the pointer all the way back to zero.
DIAPHRAGM GAGES
Diaphragmgagesaresensitiveandgive reliableindicationsofsmalldifferencesin pressure. Diaphragm gages are generally used to .,measure air pressure in the space between the inner and outer boiler casings.
The indicatiflg mechanism of a diaphragm gage, shown in figure 9-7, consists 9f a tough; pliable, neopreike rubber membrane conntdted to a metal sPring which is attached by' a simple. link* system to the gage pointer.
One side of the diaphragm is exposed to the pressure being measured, while the other side is exposed te the aftmosphere. When pressure is applied to the diaphragm,it moves upward, puthing the metal spring ahead. As the spring is pushed up, it moves the pointer, connected to it with a chain, to a higher reading on the dial. 61.4X When the pressure is lowered the diaphragm Figure 9-8.A. Standard U-tube manometer. pulls the pointer back toward the zero point. I 0 9 B. Single-tube manometer:
103 FIREMAN
measured may be that of steam to the main Ar, engines, brine in an ice machine, oil and bearingses in the main engines',4or substances in many other Q locations. In generpl, a thermometer measures POINTER changes in temperature by utilizing the effect of mkt, NT, heat on the expansion of a liquid or a gas. .01METALLIC ELEMENT Aet GAGE DIAL. Thermorhetersaredesignedas (1) direct-reading, liquid-in-glass type, (2) bimetallic 110 ORO type, or (3) distant-reading, indicating-dial type thermometers. 61.27 Figure 0.10. Bimetallic actuator for a thermometer. LIQUID-IN-GLASS THERMOMETERS
Liquid-in-glass thermometers are filled with in the glass stem. Cold, or the absence of heat, mercury, ethyl alcohol, benzine, water, or some uses the liquid-to contract and fall. other liquid suitable for the temperature range LiqUid-intlass thermometers are designed so involved.Most oftheliquid-in-glass ,That the face will be in the best positon for thermometers used in the engineering spaces are reading, ',when the thermometer is installed. filled with mercury. When a thermOmeter is Some thermometers with different angles are exposed to a temperature to be measured, heat shown in figure 9-9. causes the liquid in the bulb to expand and rise Mercury-filled Thermometers must not be misusedor improperly handled ,,because of personnel hazard. Mercury produces a highly Toxic vapor which is 'hazardous if breathed in excessive concentration.
48' RECLINED ANGLE Cr INCLINED ANGLE BIMETALLIC DIAL THERMOMETERS '* Bimetallic dial. t ermometers use a bimetal element for indicatitemperature changes on a circulardial.The' bimetallicactuatorisa single-helix coil fitted olosely to the inside of the stem tube. A rise in temperature causes the actuatingelementtoexpand.Beausethe element is composed of tw.othin strips of different metals with each metal having a different rate of expansion, the element expands by unwinding instead of by expanding against the sides of the tube. The pointer shaft is secured to the free end of the element and thus registers the-amount of element movement on' 'LEFT DICE ANGLE RIGHT GIDE ANGLE the dial face. Figure 9-10 shows the actuating element of a bimetallic thermometer.
DISTANT-READING DIAL THERMOMETERS
. 61.26 Distant-reading dial thermometers are used Figuro 9-9.Tpormometors with angle socks ts. when indicating portions of the instrument must
104 110 Chapter 9INTRUMENTS
wiresr cables inside, the armor contains a small metal tube. The capillary tubing must be BOURDON handlecarefully and must be maintained free TUBE of kinki twists, so that the mercury column PRESSURE within the ing is not distrupted. GAGE The Bourdon tube pressure gage is the same as we discussed earlier in this chapter. The gage contains a Bourd9n tube which has a tendency to straighten out as the pressure in the Bourdon CAPILLARY tube increases. TUBING Now, let us put together the three major unitsofthedistant-readingthermometer (mercury bulb, capillary tubing, and the pressure gage) and see what happens. Remember that all three of these units are filled with mercury and that when the temperature rises, the increase causes the mercury in the bulb to expand. The expansion of the mercury in the bulb causes a MERCURY %pressure to be built up in the ca illary tubing. BULB This same pressure is transrakted- hrough the capillary tubing into the Bourdon tube in the pressure gage. The Bourdon to aightens out and, through an assembly of gears and levers, 61.28X causes a pointer to move around a dial, which Figure 9-11.Distant-reeding dial thermometer. haspreviouslybeencalibratedtoshow corresponding temperatures. The expansion of the mercury in the bulb-results in a movement beplacedatadistancefrom where the of the pointer that is directly proportional to temperature isbeingmeasured.The the temperature applied to the bulb. m e rcury-filled,distant-readingthermo meter, shown in figure 9-11, is the most common type used aboard ship. There are other types, but PYROMETERS they are not commonly used aboard ship and will not be discussed. Pyrometers are used to measure temperature through a wide range, generally between 300°F Themercury-filled,distant-reading and 3,000°F. They are used aboard ship to thermometer (fig. 9 -I I-) consists of a mercury mea u bulb, capillary temperaturesin heattreatment tubing, and a Bourdon tube fuaces,inexhaust temperatures of diesel pressure gage. The mercury bulb, the capillary en:es, a d for other similar purposes. tubing, and the Bourdon tube in the pressure gage are all filled with mercury. e pyrometer includes a thermocouple and The mercury bulb is the sensing element. It ameter. The thermocouple, made of two is inserted and fastened securely (eithk- threaded issimilar metals joined together at one end, 4or bolted) in an opening in a pipe lior turbine produces an electric current when heat is applied pump casilig, for instance, where a temperature atits joined end. The meter, calibratedin measurement is desired. degrees,indicatesthetemperatureatthe thermocouple.Figure9-12illustratesthe The capillary tubing is constructed similarly operating principle of the thermocouple of the to armored electric cable, but instead of having pyrometer.
105 FIREMAN
chamber tothemercury-filled bulb of the indicator gage, and another line connects the space above the mercury column to the top of the tank. Since the height of the liquid in the tank has a definit4 relationship to theprosswe 7e0PCIA71100 0A.50 exerted by the liquid,the scale can be caliblated izirid.A -- (341M773.127C1104.1011AT00 70 09HCA70 700.*072Altrae) I to show the height (or liquid level). Whethe height`of the liquid in the tank is known, the LITAL measurement of height can be readily converted to volume (gallons).
GAGE GLASSES o 61.34X Figura 9`12. Diagrammatic arrangomont of a tharmocoupla. The gage glass is qne of the simplest kinds of liquid level indicators. Gage glasses are used on boilers, on deaerating feed tanks, on inspection LIQUID LEVEL INDICATORS tanks, and on other shipboard machinery. Gage glassesvaryindesignandconstruction Intheengineeringplantaboardship, dependinguponpressureorotherservice operating personnel must frequently know the conditions. level of various liquids in various locations. The The liquid level in the gage glass is the same level of the water in the ship's boilers is an as theliquidlevel in the container, and the example of a liquid level that must be known at liquidlevel canbedeterminedbyvisual all times. Other liquid levels that must be known are thelevelofthefueloilin, storage tanks and service tanks, the level of theqvater in the deaerating feed tank, and the level of the lubricating oil in the oil sumps and reservoirs of pumps and other auxiliary machinery.
Liquid level indicators, other than sounding rods and ta'es, are constructed in a variety of designs and sizes; some are simple and some are MERCURY relatively complex. Some indicators measure BASE liquid level directly by measuring the height of a column of liquid. OIL IN
TANK GAGING SYSTEM
CONTROL... One of themost common liquidlevel VALVE indicatorsisthestatic head gaging system, COMPRESSED AIR SUPPLY shown in figure 9-13. This type indicator is generally used to measure the liquid level in fuel BALANCE CHAMBER oilstorage tanks aboard ship. This system uses a mercury manometer to balance a head of liquid /- ORIFICt in the tank against the column of liquid in the manometer. The balance chamber is located so that its orifice (opening) is near the bottom of 61.5X the tank. A line connects the top of the balance Figure 9-13.Static head gaging system..
1 106 112 ( hapter 9INS! N IS
°139.32 Figure 9-14.Boiler gage glass installed on a boiler.
observation. A typical boiler gage glass installed gasoline, and other liquids. You cannot getan on a boiler is shown in figure 9-14. accurate measurement of the rate of flow of a In addition to the gage glasses. some boilers liquidthrough a meter finless therecorded are equipped with remote. water level indicators. amount is read correctly. Some different types The remote water level indicators are generally of dials used on fluid meters are shown in figures installed on the operating level of the boilers to 9-16 and 9-17. TI R- dial readingsare generally in provide the petty officer in charge with ci readily U.S. gallons unless otherwise specified on the obtainable reading of the water levelinthe dial face. The dial faces shown in figure 9-16 are steam drum of the boilers. Figure 9-15 illustrates far the straight-reading type meter: the dial faces one type of reIl ate water level indicator. shown infigure 9-17 are for a round reading meter. TUID ME,IERS Fo read the stright-reading meter, read from Fluidmetersare usedaboardshipto left to right and add sthe number indicated by measure flow rate of fuel oil, diesel oil, water, the smaller pointer above. For example, in part ti107 FIREMAN
A of figure 9-16 the reading is 0000280. Part B shows the reading to be 0000285. As the pointer turns, so does the righiphand, numbered roller. Even though the next higher. number is partly
0 exposed always read the lesser number,'which.is the number disappearing frond sight. When the small pointerisat 0 all the numbers in the straight-reading dial will be centrally aligned, as shown in part A and part G of figure 9-16. When the small pointer is at 8 or 9 (part C of fig. 9-16), the next larger number on the numbered rolleris almost completely exposed, but the lesser number must be read. The dial in part C of figure 9-16 reads 288 gallons, not 298 gallons. 1 To read the round-reading dialface(fig. 9-17) take the lesser number of the two between which the hand points in each circle. Notice that each circle indicates tens, hundreds, thousands, tens of thousands, etc. Place the number taken from thecircle marked "tens" in-The units position, place the number taken from the circle narked "hundreds" inthe tensplace; and 14 $.0 ALLONS -414 MS
tJy41.0
41, kt:A.
4.
61.13.1X Figure 9-16.Straight reading registers. ww,...1.
g
139.33 61.13.2X Figure 9-15.Reroote water level indicator. Figure 9-17.Round reading registers. 114 108 10. Chaptef 9INSTRUMENTS
coittinue similarly for the remaining circles. The most common instrument used in the Each division of any circle stands for one -tenth engineeringplantaboard shipto measure of the whole number indicated by that circle. If rotational Speed is the tachometer. For most a hand is o or near a numbers read that number shipboardmachinery,rotational speedis instead of tale next lower number when the hand expressed in revolutions per minute (rpm). The in the circle is on or past 0. tachometers generally used aboard ship are of three main types: centrifugal, chronometric, and resonant. REVOLUTION COUNTERS AND INDICATORS The..CENTRIFUGAL tachometer may be either portable (single and multiple range) or permanently mounted. The portable multirange Measurementsofrotationalspeedare tachometer has three ranges: low (50 to 500 necessary for the operation of the pumps, forced rpm), medium (500 to 5,000 rpni), and high draftblowers,mainengines,andother (5,000 to 50,000 rpm). Do not shift from one machinery or equipment of the engineering range to another while the poytable centrifugal plant. As a result, various instruments are used tachometer is in use. to indicate the shaft speed or to count the number of turns a shaft makes.. One type of Normally, permanently mounted centrifugal instrument, the revolution counter, which is tachometersoperateoffthegovernoror mountedonthethrottleboardinthe speed-limitingassembly.Thetachometer engineroom, counts the total number of turns continuously records the actual rotational speed that are made by a main propulsion shaft. These of the rhachinery shaft.permanently mounted counters are similar to the speedometer of an centrifugal tachometer is illustrated in figure automobile. A typical revolution counteris 9-19. shoiwn in figure 9-18. Theportablecentrifupjtachometeris operatedmanually. A smallshaftwhich protrudes from the tachometer case is applied manually to a depression or projection on the end of a rotating shaft of a pump, motor`,or other machinery. The centrifugal or rotating movement of the machinery ,,soft is converted to instantaneous values of s1,ecl.on the dial face of the tachometer. Figure 9-20 showsa portable multirange centrifugal tachometer. Theportable PHRONOMETRIC tachometer,showninfigure, 9-21,isa combination watch and rdvolution counter. It measures' the average number of revolutions per minute of a motor shaft, pump shaft, etc. This tachometer has an outer drive 'shaft whichruns free when applied to a rotating shaft, untila starting buttori is depressed to start the timing element. Note the starting button beneath the index finger in figure 9.21. The chronometric tichOmeter retains readings on its dial after its/ drive shaft has been disengaged froma rotating 7.143 shaft, until the pointers' are returned to zero.by Figu8. Revolution counter. the reset button (usually the starting button).
109 FIREMAN
38.111X Figure 9-19.Permanently mounted centrifugal type tachometer on a forced draft blovkr.
110 116 Chapter 9INSTRUMENTS
61.17X Figure 9- 20. Multiranga centrifugal tachometer.
The range of a chronometric tachbitieter is usually from 0 to 10,000 rpm andlrom 0 to 3,000 feet per minute (fpm). Each portable centrifugal or chronomJtric tachometer has a small rubber covered wheel anda number of hardrubbertips.The appropriate tip or wheel is fitted on the end of the tachometer drive shaft and held against the shaft to be measured. Portable tachometers of th0 centrifugal or chronometric type are used for iritumittent readings only, andare not used fol. continuous operation. The RESONANT REED tachometer, illustrated in figure 9-22, is particularly useful for measuring high rotational speeds sjichas those that occur in turbines and generators. This type tachometer is particularly suitable when it is practically impossible to reach the moving ends of the machinery shafts. This instrument gives continuous readings andiscapable of 2.66X makin rap , instantaneous adjustments to Figure 9.21. Portable chronometric tachometer. rotational spd.
111 1
FIREMAN
Resonance is the quality of an elastic body alarms,superheatersteamflowindiCators, which causesitto vibratevigorously when smoke indicators, salinity indicators, lube oil subjected to small, rhythmic impluses at a rate pressurealarms, engine order telegraph, and equato, or near, its natural frequency. Ip a many others. reso ant reed tachometer, resonance provides a simp a but accurate means to measure speed and SUPERHEATER TEMPERATURE ALARMS rate of vibration. Superheater temperature alarms are installed A resonant reed tachometer consists of a set on most boilers to warn operating personnel of of consecutively tuned steel'reeds mounted in a dangerouslyhightemperaturesinthe mse with a scale to indicate rpm of the shaft and vibrations per minute (vpm) of the reeds. This superheater of the boilers. Some superheater temperature alarms operatesimilarlyto the asetof `tachomethas nopointeronly Bourdon tube pressure gage. As heat is applied, accurately tuned reedsand it operates without the mercury in the spiral-wound Bourdon tube direct contact with a moving part under test. It expands, causing the Bourdon tube to move a has no gears or couplings, and it _requires no cantilever arm toward an electric microswitch. oilingiland practically no maintenance. As the preset alarm temperature is reached, the cantilever arm engages the microswitch, setting OTHER ENGINEERING INSTRUMENTS of a warning howl or buzzer. The warning signal continues until the superheater temperature has Therearea great number of additional been lowered to approximately 10° or 15°F, instrumentsandindicatorsusedinthe below the preset alarm temperature. The signal engineering plant. This section will acquaint you or alarm stops because the mercury in the with those additonal instruments which you Bourdon tube contracts, moving the Bourdon most likely will be seeing or working with in the tube, which in turn causes the cantilever arm to engineeringdepartment.Theseadditional move away from the microswitch, shutting off instrumentsincludesuperheater temperature the alarin. A diagrammatic arrangement of one type of superheater alarm is shown in figure 9-23.
STEAMFLOW, INDICATOR
Steam flow indicators'91).1)Wthe rate of flow ofsteamthroughthesuperheaterof
PIVOT POINT
SPIRAL STEEL CAPILLARY TUBE BOOR DON TUBE
MERCURY FILL ED BULB
CANTILEVER mICROSwiTcH ARM
ADJUSTER FOR SE TTINC. ALARM TEMPERATURE
61.16X 61.31 X Figure 9-22.Mounted resonant reedtacImeter. Figure 9-23.Superheater temperature alarm.
112 118 Chapter 9INSTRUMENTS.
VISION COVER UPTAKE GLASS I BULL'S-EYE CLAMP LENS CASING LAMP REFLECTOR [!'".11;_Irk\/1N , UNIT wed
LINE OF SIGHT 41: A.. -48,43.403111 N', w .111: ADJUSTABLE 1 COVER ,w, 'No CLAMP MIRROR ee LAMP UNIT LOCK NUT
.27 LOCK. NUT
ADJUSTABLE MIRROR
LINES
VISION Ut'iT
COVER CLAMP
38.60 Figure9-24.Smokeindicator.
double-furnace boilers. Beforefires are lighted in SMOKE INDICATOR the superheated side of double-furnacebaiitirs, the operator must ensure thata sufficient flow of steam-is passing through the superheater. Smoke indicators (periscope type) provide The the boiler operator With visual indications flowof steam is necessary tocarry off the heat of Ofcombustioninthe conditions in the stack above the furnacearea. A superheatedsideof smoke indicatorIS shown in figure double-furnaceboilersinordertoprevent 9-24. overheating of the superheater tubes, drums, and headers. SALINITY INDICATOR The steam flow indicator is calibrated in inches and is normally set at 2 inchesas the Electrical salinity indicating cells (fig.9-25) minimum low. In other words, fires shouldnot areinstallFdthroughout distilling belighted plakts to in thesuperheatedsideof maintain a constant check on the distilledwater. double-furnace boilers until the .pointeron the An electricalsalinityindicator consists of a steam flow indicator has reached the 2-inch numberofsalinity 'cells ,in various locations in mark, which is an indication of sufficientflow theplant; for example, in the evaporators, pf steam. condensate pump discharge, and the air-ejector
113 1 1 1.0
FIREMAN
ringing bell or loud siren, receives its signal from the bearing that is the most) remote from the lube oil pump. When the alarm is sounded, the affectedmachinerymustbestopped immediately,the causedetermined,and corrective measures taken. ENGINE ORDER TELEGRAPH The engine order telegraph (speed indicator), shown in figure 9-26, relays the speed requested by the officer of the deck while underway to the throttlemaninthe engineropm. The engine order telegraphis generally mounted on the throttleboard adjacent to the throttle valves, so that it is readily visible to the throttleman. The following table lists speed changes which may be indicated via the engine order telegraph.
7150 Figure 9-25.Salinity cell and valve assembly. condenser' drain. Thesesalinitycellsareall connected to a Salinity indicator panel. a Since the electrical resistance ora solution varies according to the amount of ionized salts in solution, it is possible to measure salinity by measuring the electrical 'resistance. The salinity indicatorpanelisequipped 1 withameter calibrated to read directly either in equivalents per million (epm) or in grains per gallon (gpg). The newer type salinity indicators are calibrated in epm. LUBE OIL PRESSURE ALARM Lube oil pressure alarms are installed oncall generators and Inain propulsion engines to signal when the lube oil pressure to the bearings is dangerously low. Low lube oilpressure,, can cause a number of casualties that will impair the operating condition of- the machinery invlved. 7.116 The lube oil pressure, whichw is either a rapidly Figure 646.Engine order telegraph.
114 10 'A 4 4
Chapter 9INSTRUMI NTS Ahead Stop Astern The wrong direction alarm is connected 1/3 to 1/3 the engine order telegraph and the mainengine 2/3 2/3 throttle valves.If the engine order telegraph I Standard Full . indicates "ahead" and the throttlemanattempts i II Full to open the astern throttle valve, a loud signal III Plank or ' alarm is sounded.- -
Q
A
121 .
115 b
CHAPTER 10
r ob. PUMPS, VALVES, AND PIPING 4
A Fireinan, you should have. a general If a system has a 'pump, it must also contain knowled of the basic operating principles of devices for controlling the volume of,flow, the the various pes' of pumps used by the Navy. direction of flovy, or theoperattng pressure of Pumps are used to move any substance which the system. A device that performs one or more flows or which can be made-to flow. When of these control functions is called a VALVE. thinking of the term pumj,ing, you probably In addition to 'pumps and valves,. in this think of movineWater, oil, air, steam, and other chapter we shall discuss pipipg which is a vital common liquids and gases. Substances such as part of the sliip's engineering plant. s molten Metal, sludge, and mud are alsO fluids and can be pumped with specially designed
pumps. . PUMPS A pump is a device which suses an external 4 source of power to Apply a force to a fluid in Pumps are classified by their ,design .and order to pc ove the fluid from one place to operational features. Pumps are further classified another. *pump transforms energy from the bythe type .of. movement that causes the external source (such as ar4 electric motor or pumpip-rr'actionv (reciprocating,rotary, steam turbine) "nto :mechanical kinetic energy, centrifugal, propsller, or jet pumps). Pumps are which is reveal d by the motion of the fluid. also classified by the rate of speed, the rate of This kinetic en i en used to do work, discharge, eand the method of priming. Some such as:toraise a liquid,- from one level to pumps run at variable speed; others at constant another, as when lifting 'Water from a well; to speed. Some pumps have a variable capacity; transport a liquid through a pipe, as in an oil others discharge at a constant rate. Some pumps pipeline;tomovealiquidagainst some areself-priming; -othersrequireapositive resistance as when filling a boiler under pressure; pressure on the suction (intake) side before they or to force a liquid througha hydrais system ,can begin to move a liquid. against variptus resistances. Regardless of classificatippump must Aboard ship, pumps are used for a number have- a POWER END and asPe.-OiD .END:-The of essential services. Pumps,supply water tp the power. end maybea *am turbine,a boilers, draw condensate from the condensers, reciprocating steam engine; steam jet, or an supply sea,water tothefiremain,circulate electric motor.In . steam-driven pumps,' the cooling water for coolers and condensers, pump power end is oftenalled the STEAM END. The out bilges, transfer fuel. oil, 4upply sea water to fluid end is generally called the PUMP END; but thedistilling' plants,and serve ;many other it may be called the LIQUID END, theA R purposes. The operation of the ship's propulsion END, thr-011--....EXILgs.,--the GAS N to plant and of almost all the auxiliary machinery indicate' thf nature of the IPuid substpce b ing depends on the proper operation of pumps. 'Rumpedi ,gump failure may cause failure Of an entire Pufpscan be divided into groups accofding power plant, although most plan s have two .to the principles on which they operate. Most pumpsa main pump and a standb Dump. pumps fall into five pain types: reciprocating,
116
4%, I clv
Chapter 10 PUMPS, VALVES,AND PIPING
rotary, centrifugal, 'propeller, and jet. Eachtype or'pump is especially suited forsome particular kind of work.
RECIPROCATINGPUMPS
The hand water pump commonlyused on farms is a good example of thereciprocating pump. The reciprocating ptgair, derives itsname from the back and forthor up and down movement of the Piston or plunger insidea cylinder. These pumpsare used on modern ships asemergencyfeedwaterpumpsandas emergency fire and bilge pumps. ReciprocatOri pumps are used for emergencypurposes because they are easy to operate andcan be started safelyby relatively inexperiencedpersonnel. These pumps are also reliable for startingunder cold conditions. 139.34 A single- acting pump isone which takes a Figure 10-1.Orrating principle oftwo typos of suction on one stroke only,known as the reciprocating pumps. suction stroke. On the return strokecalledthe discharge strokethe liquid is forcedout of the 1 cylinder. Figure 10-1A illustrat?sthe operating type except that the valve .system isarra ged principle of a single-acting reciprocatingpump. ,..differently, and an air ,chamberis added to maintain the pressure when the piston Theprincipalpartsof a .single-acting is at the top and bottom of each stroke...... _ , reciprocating pump are a Fylinderapiston, and a valve system. The piston fits ?nugly inthe A stream of water is forcedout of the cylinder and is movedup and down in the double-acting pump on both 'theup and the cylinder by the punipp4haft. Mostof these down strokes. On theup stroke, the water above pumps are steam-dtilkn. "The pump shaft isa the piston is forced out through theupper outlet continuation of the piston rodof the steam valve. At the same time, 'fateris being drawn cylinder. , into the space below the pistonthrough the On the down stroke, the valvesin the lower 'inlet valve. On the downstroke, the water bottom of the cylinder arerclosed andthe water below the piston is forced-out of (discharged in the lower part of the cylinder isforced up from) the cylinder throughthe lower outlet through the valves in the pistbn: Onthe up calve and a new charge ofwater is drawn into strokes, the weight of the water abovethe piston the top of the cylinder throughthe upper inlet closes the piston valves. As the pistonmoves valve. upward, it draws the water from thesuction line into theylinder through the cylinder valves. Reciprocatingpumpsareoftencalled The water abo the piston leaves thepump POSITIVE DISPLACEMENTpumpsthat is, through an outlet line ora spout. eachdischargestrokedisplacesadefinite' The double-acting Ohm shownin figure 'amount of liquid, regardless ofthe resistances 10-1 B delivers a steadystream of water under against which thepump is operating. A relief high pressure.Double-acting pumps are, also valve must be installed in thedischarge line to relieve any excess st steam-driven. The pump is connecteddirectly to pressure. the piston rod of the steam cylinder. These The operation of the reciprocatingpump pumps have the same general parts and operate generally dependson a valve system which on the same general principle as the single-acting direas the steam Firstin d one end of the 117 123 FIREMAN
STEAM rrEST
Ant .1171
'EXI1AOST PORT SI LIVE OTEALi PACE
STGALI PORT PO(PILOT VALVE P15* TEAL, PILOT VALVE
139.35 UAW STE PL5T014 T Figure 10-2.Operating principle of D-shaped slick VALVE valve of a redprocating pump. . AUTgAWD ff . cylinder and then into the other end. The steam is allowed to escape from the cylinder after it has served its purpose. Steam to and from the cylinder passes through two ports (opepings), one ineachendofthecylinder.This arrangement is quite similar to the manner in 32.99 whichthewaterpassesthroughthe Figure 10-3.Piston-type valve gear for steam and of double-acting water pump described previously. reciprocating pump. One valve design consists of a D- SItAPED SLIDE VALVE (D-valve) that is actuated by a cylinder port is connected to the exhaust port linkage attached to the piston rod. (See fig. through the back of the valve. As the,piston 10-2.) The steam chest which is attached to rises, it pushes the exhaust steam out at the toP the cylinder is connected through a stop valve to of the cylinder through the exhaust port. the auxiliary 'steam line. When the piston reaches a thetopofitssfroke,the valve-operating Figure10-3 shows the piston valve gear mechanism movesthevalvedowntothe commonly used aboard ship. It performs the position showninfigure10-2A. The port same function as the D-valve, but the movement connecting the steam chest to the 'pace at the of the valve is controlled by the difference in the top of.the cylinder is uncovered. Steam from the steam pressure between the inlet and the outlet. chest flows through this port, exerts a pressure Thepistonvalvegear consists of a main onthetopof thepiston, andforcesit piston-type slide valve and a pilot slide valve. downward. Since the rod from the pilot valve is connected At the same time, the space belolk the piston to the pump rod by a valve-operating assembly, is connected with the exhaust port through a the position of the pilot valve is controlled by recess in the back of the valVe. As the piston the position of the piston in the steam cylinder. The pilot valve furnishes actuating steam to the moves downward, tke steam that fills this space main piston valve; this in turn admits steam to is forced out through the exhaust port. the top or to the bottom of the steam cylinder As the piston nears the bottom of its stroke, at the proper time. the valve mechanism moves the D-valve to theor. position shown in figure I0-2B. This, movement Regardless of the type of valve used, the fivers the lower port. Steam froth the chest continued operation of tholyump consists of now flows into the lower-re of the cylinder feeding steam into one end" of the cylinder and and pushesthepistonupward. The upper exhausting it from the other end. The direction
118 124 Chapter10PUMPS,VALVES, AND PIPING
of steam flow (in and out of thecylinder ports) , is reversed at the end of each stroke of the WW1 piston. . tWil" cnt-411 Startingarecipfocating p pIsquite simple.First, open the proper v s in the rates:4 suction and discharge lines beforesta ing the pump. Next, open the exhaust valve and the cylinder drains. Then open the throttle valve slightly, or "crack" it to feed enoughsteam Into the cylinder to warm it. Adjust the throttleto perate the pump at a slow speed until live W:111 Nati s eam begins to come out of the drains. Now 11,11=41 SHAM c1ose 1110-0( the drains and adjust the throttleto (A) operate the pump at the desired speed. When securing a reciprocating pump, close 139.37 the throttle first, and then closethe exhaust Fiouro 10 4. Operating principlo ofa Waterbury valve. Next open the cylinder drainsand close ,,,the valves in the suction and dischargelines. After the steam cylinder has drained, close the drain valves. Figure 10-4illustratestheoperating principle of a Waterbury variable-volumepump. Variable Stroke Pumps This pump is used as a variable-speedpower transmissioninthesteeringgearand the gun-training mechanism aboard ship. Itis also Aboard ship, variable strokepumps (positive used in those systems where it are is necessary to displacement) usedlargelyon control the pump output withinvery narrow electrohydraulic steering gear, elevators,cranes, limits. and anchor windlasses. In these applications, the In the Waterbury pump thep,dpingis done variable stroke pump is referred toas the A-end by a set of pistons whichmove back and forth of the drive system and the hydraulicmotor within close-fitting cylinders. The which is driven by the A-end is referred oil enter and to as the leaves the cylinders through portsor pass B-end. By controlling the pumping action es in of the the cylinder heads. The pistonsare operat d by A-end, you can run the motor (B-end) in'either the cam action of a tilting plate. Thisme od of direction and vary the speed fromzero to the changing rotary motion to reciprocating maximum rate. On some naval ships, (back variable and forth) motion is demonstratedby the device stroke pumps are also usedas in-port and shown in figure 10-4. cruising fuel oil service pumps. This demonstrator consists ofa cykpder Although variable stroke pumpsare often barrel and a tilting plate attachedto a shaft, as classified Ai rotary pumps, theyare actually illustrated in figure 10-4A. Thetilting plate is reciprocating'sumps.Theyoperateona fastened to the shaft bya universal joint which' principlesimilartothatof -asingle-acting permitsittotiltinanydirection.The reciprocatingpump. Arotarymotionis connecting rods (piston rods)rest in sockets in imparted to a cylinder barrel or cylinder block the tilting plate andare,attached to pistons inthe pump by means of a constant-speed which slide up and down inthe cylinders. When electric motor, but the actual pumping isdone the handwheel is turned the completeassembly by a set of pistons reciprocating insidea set of turns with it. cylinders. When you place the demonstratoron a sloping surface the tilting plate willtip or, tilt Let us discuss the way thatthe rotary and assume the same angle motion is changed to reciprocating motion. as the block. The pistons on the low side will be drawndown in
5 CONTROL SHP! PLA'f 1:1001 RU;) *vt hnfRBARRit P Sfth
TIL 71NG \. Btu, K
11; 4:1
MAIN SHAFT -a
'HAFT TRUNNION BLOCK
SOCKET RING DIAGRAM - TILTING BLOCK POs"ilikk,
FORWARD REVIR4
1
I
I Chapter 10 PUMPS, VALVES,AND PIPING the cylinders, and those on the high side will be ROTARY PUMPS pushed up. In figure 10-4A thenumber 1 piston is in the lowest position;number 3 is in the highest. All rotary pumps work.bymeans of rotating parts which trap the liquid atthe suction side of the pump casing and forceit through the Now turn the handwheel to theright, and discharge outlet. Gears, see what happens. As the far side of the tilting screws, lobes, and vanes are commonly used as the rotatingelements in plate moves up along the surfaceof the block, rotary pumps. the connecting rods and pistonson that side will be raised. The near side of theplate will be Rotary pumps (positive displacement) moving down along the blocksurface and the are most useful for pumping oil and"other heavy pistons on this side willmove down in tht viscousliquids.They cylinders.The operation is continuous. Each arealsousedfor nonviscous liquids, suchas water or gasoline, piston moves up during half ofeach revolution where the pumping problem around the shaft, andmoves down during the involves a high other half. suction lift. Rotarypumps are used for fuel oil service,fueloiltransfer, and lubricating oil service. These pumps The stroke of the pistons (the are self-priming, because distance that they are able toremove air from the suction they move up and down during eachrevolution lines and produce of the shaft) depends a high suction lift (or a on the slope or tilt of the satisfactory vacuum). tilting plate. In figure 10-4B thedemonstrator is resting on a levelsurface, and the tilting plate is The simple GEAR PUMP,shown in figure parallel to the bottom of thecylinder barrel. 10-6is When you turn the handwheel frequentlyusedinthe lulricating now, the tilting systems of fuel oil andwater pumps, forced platewill' not move up and down,and the draft blowers and other pistons will remain in thesame position in the auxiliary machinery. cylinders. This type of pump has twospur pars which mesh together and rotate inopposi+ directions; So far, the demonstrator one is the drivinittl tthe other is thedriven has been used to gear. The driving gear istached to the shaft of show that the pistons willmove up and down in the electric motor the cylinders when the shaft is or steam turbine that drives turned with the the pump; the drivengear is in mesh with the angle plate tilted. The devicecan be converted into an oil pump by adding driving gear and is driven byit. The gears must an adjustable tilting fit very closely within thecase so tliat the liquid box to control the tilt of the tiltingplate and by will not leak back to the suction placing a valve plateon top of the cylinder side of the pump. The parts are lubricated by theliquid barrel. The valve plate has two elongatedports being pumped. which allow the oil to flow into thecylinders on one side of the pump and outon the,other side. When the tilt of the tilting plate isincreased, the DISCHARGE stroke of the pistons is increasedand more oil passes through the pump. Tilting the tittingplate in the opposite directionreverses the direction of the oil flow.
The variable stroke axial pistonpump (fig. 10-5) has the same pOncipalpartsas the demonstrator just described in figure10-4. The moving parts are enclosed ina pump case that is kept filled with oil. Thesepumps are mounted in SUCTION a horizontal position and are usually drivenby an electric motor. 38.108 127 Figure10.8. Action of simple gearpump. 121 FIREMAN -
At first glance, you mightthink that the liquid passes be n the two gears. This is not true. As the gearotate, the liquid is trapped in FLEXIBLE the spaces beten the gear teeth and the pump COUPLING case and is ca*ed around to the discharge side of the pump. As the teeth come in mesh, the UPPER THRU liquid is squeezed out of these spaces and is kept PLATE from returning to the suction side of the pump. Pressure is built up and forces the liquid out of the pump into the discharge line. IDLER 00WER ROTO4
ROTOR HOUSING There are several variations of the simple IDLER gear pump. One kind has herringboneteeth (fig. DISCHARGE 10-7) which make little noise and maintain an SUCTION even pressure. Another kind has threelobes on SPACER each gear instead of teeth. Lobe pumps and RING some helical pumps have timing gears which pone ROTOR HOUSING rotate the pump parts.All of these pumps LOCATING operate on the same principle, as the simple gear IDLER LOCATING OWER pump just described. CAPS PELATTROST SCREW PUMPS represent still another type of positive displacement rotary pump. In the screw pump, the liquid is trapped andforced through the pump by the action of rotating 47.80 screws. Screw pumps have few moving partsand Figure 10- 8. Cutaworview of triple screw, - no valves to get out of order. They are widely high pitch pump. used aboard ships as fuel oil and lubricating oil service pumps. They may have two or three screws and are divided into high pitch and low pitch types. Tltie triplescrewpump(high-pitch) illustrated in figure10-8 has three screws or rotorswhichrevolvewithinaclose-fitting HAND DRIVE "housing. The power rotor in the center is in mesh with sand drives) the two idling rotors (idlers). The suction line is connected to the pump intake, which in turn opens into the chambers at
11111,11.1111 the ends 'of the rotors. As the rotor turns, the liquid flows in between the threads at the outer end each pair of screws. At the end of the first turn, a spiral-shaped slug of the liquid is trapped when the ends of the threads come in mesh again. The threads carry the liquid along within the housing toward the center of the pump and to the discharge opening.
CENTRIFUGAL PUMPS
-38.104 Centrifugal pumps are used in the feed, fresh Figure 10-7.Herringbone gear pump. water, and fire main systems of the engineering
122 128' Chapter 10PUMPS, VALVES, AND PIPING plant. There are many types of centrifugal tank from ,which suction is' to betaken. When pumps (feedwater booster,condensate, and fire), but all operate onthe the intake valve is opened the liquidflows into same principle. the pump arid primes it. The vent cockshould Centrifugal pumps canhandle large quantities of be opened until all air is purged front thepump a liquid and deliver it at a high pressured. These casing. pumps may be .driven by a steam turbine,an electric motor, or a diesel engine. They do not Asingle-impellerpumpwillmaintain operate on the positive displacement principle, pressures up to 150 psi. Where higher pressures but depend on centrifugal force to move the aye required the pump is designed with fromtwo liquids through, the pump and to maintainthe to ',six Openers. Thepressure is desired Pressure. (See fig. 10-9.) raised by succeksivestages. The outlet from thefirst impeller is connected to the inlet ofthe second When a body revolves ina curved path, it impeller and so on through all the stages. exerts a "centrifugal force" upon the ,e casing, or whatever means is used restrain it. PROPELLER PUMPS from moving in a straight (tangen' al) line.For example, centrifugal force is the frce that holds Propeller pumps ary used the water in a pail when on some ships as you swinit in a circle circulatingwater pumps.(Seefig.10-10.) Over your head. If there happensto be a hole in Propeller pumps closely resemble centrifugal the bottom of the pail, the water will squirt out, pumps in design and operation but do notuse even when .the pail is upside down. centrifugal force for their operation.
The simple centrifugal pump shown in figure Propeller pumps are usedon some ships as 10-9 has only one main moving part. Awheel circulating pumps (fig. 10-10). called an impeller is connected to the drive shaft and rotates within the pump casing. The casing has the same spiral shape as the snail's shell. The water enters the pump through the inlet pipe, CASING which empties into the center of the casing. The END PLATE location of the outlet passage corresponds to the opening in the snail's shell through whichthe snail emerges. SUCTION The suction connection is so designed that the liquid is guided from the suction chamber of VENT COCK DISCHARGE the casing to the center or' "eye" of the impeller. As the impeller rotates, itcarries the water CURVED VANES around with it. The centrifugal force resulting IMPELLER from this rotation pushes the wateraway from the center and holds it against the inside ofthe CASING pump casing. As the water flows along the inside END VOLUTE PLATE DIFFUSER of the spiral-shaped casing, it is diverted through JOINT the outlet opening and passes into the discharge line.
DRAIN Centrifugal pumps are not self-priming: they CONN. should NEVER be run while empty.The impeller fits very closely into the sides ofthe casing and depends on the liquid being pumped to supply the necessary coolant. This type of pump is usually installed below the level of the 139.38X Figure 10-9.-1-s sting principle ofa centrifugal pump. 123 129, FIREMAN
TURBINE CASING
EXHAUST
STEAM CHEST'
BULL GEAR THRUST BEARING
a A WATER OUTLET STUFFING BOXa PACKING RINGS
THRUST BUSHING
WATER 'PROPELLER' LUBRICATEO BEARING WATER INLET
47.37 Figure 10-10.Main condenser circulating (propeller) pump (showing reduction gearing).
The propeller pump has a propeller closely JET PUMPS fittedintoa tubelikecasing. The propeller pumps the liquid by pushing it in a direction All the pumps previously described require parallel to the shaft. motors or turbines to drive-them. However, jet Propeller pumps must be located either pumps have no moving parts. The flow through below or only slightly above the surface of the the pump is maintained by a jet of water or liquid to be pumped, since they cannot operate steam which passes through a nozzle at a high with a high suction lift. velocity.
124 s.4 Chapter 10PUMPS, VALVES, AND PIPIT
Jetpump's' aregenerallyclassifiedas the fluid up through the inlet (D) into the EJECTORS (which use a jet of steam to entrain chamber and mit through the discharge line. and transport air, water, or other fluid) and Thus, pumping action is established. EDUCTORS (which use a flow of water to entrain and pump fluids). The basic principle of Jetpumpsoftheejectortypeare' operation of these two devices is identical. occasionally used, aboard ship to pump small. quantities of drainage overboard. Their primary A simple jet pump of the ejector type is use on naval ships is to remove air and o'c'her shown in figure10-11. In this pump, steam noncondensablegasesfromthemainand under pressure enters the chamber (C) througha auxiliary condensers. pipe (A) which is fitted with a venturi-shaped nozzle (B) having a reduced area which increases Figure 1042 shows a portable eductor of the type found in damage control lockers. the velocity of the steam., The , fluid in the The chamber at pbint F, in' front of the nozzle, is principle of operationisthe, same as that driven out of the pump through the discharge described for the ejector type of jetpump;. but line (E) by the force of the steam jet. The size of water is used instead of steam. All the water the dischaige line increases gradually beyon"d the which enters the large end of the jet mustgo out chambertodecreasethevelocityof the through the small end. Since the exit endis discharge. As the steam jet forcessome oftthe smaller than the entrance end, the water leaving fluid from the chaniber into the discharge line, the jet will have a greater velocity thanit had pressure in the chamber is lowered and the upon entering the jet. The venturi-shape of the pressure on Plig- surface of the supply fluid forces' diverging nozzles causes a lowpressure area, creating suction which draws water through the strainer and entrains it through the diverging nozzle. This ensures a constant flow. 1 Eductors may also be used for salvage work and with fog or foam equipment. Eductors will operate when entirely submerged ina flooded compartmentbandwilldischargeagainsta E moderate pressure. Although fire and bilge pumps are still being installed in new ships, fixed-type eductorsare the principal means of pumping water overboard through the drainage system. By theuse of eductors, centrifugal fire pumps, can serve as drainage pumps without having torun the risk ATMOSPHERIC of fouling the pump with debris present in the PRESSURE bilges; this is especially useful when there has been damage to a ship.
CONSTANT-PRESSURE PUMP GOVERNORS
Constant-pressure pump governors used in theNavyareappliedalmostentirelyto steam-driven pumps, both rotary and centrifugal types.A constant-pressurepump governor 75.283 operatestomaintainaconstantdischarge Figure 10-11.Jet pump (ejector type). pressure, regardless of pump capacity or output.
125 131 FIREMAN
DISCHARGE OVERBOARD
IDIVERGING NOZZLE
DISCHARGE FROM FIRE PUMP
VENTURI
o°
SUCTION] STRAINER
47.48 Figure 10-12.Eductor.
Theconstant-pressurepumpgovernor A constant-pressure pump governor for a (sometimes referred to as pressure regulating) lubricating oil service pump is shown in figure consists essentially of an automatic throttling 10-13. The governors used on fuel oil service valve installed in the steam supply line to the pumps and on main feed pumps are of the same pump's driving unit. A pipeline connects the type. The size of the upper diaphragm and the governortothepump'sdischarge-line. amount of spring tension vary on governors used Variations in discharge Pressure, or in pressure for different services. You will find detailed differential, actuate the governor, causing it to informationconcerningtheoperationand regulate the pump speed by varying the flow of adjustment of governors in chapter 9470 of steam to the driving unit. Nav Ships.Technical Manual.
126 132 if I
I ss:i-,,,,ii '-ter 1:,, ADJUSTING SCREW
0 DIAPHRAGM g g
1.01 -7.7,6i411'. °ifotsmarlili I\ NEEDLE VALVE if-.440401k. ROM PUMP DISCHARGE; III r 4111 Ilk DIAPHRAGM
DIAPHRAGM GUIDE rIr.! 4PPbr,- AUX. VALVE DIAPHRAGM 4111-1.-PISTON NI NI ,ammur icipurIi1 Lima; NE+ 11Air-i4"-- ki 'TIIIIII* No iv Ito zi N. 7IOU jrLI' 1114 MAIN VALVE .
I
38.90 Figure 10-13.Constant-pressure pump governor. 1 3
127 FIREMAN
VALVES
10 LIST AP PARTS 3 PART NO. NAME OF PART 2 Most of tile equipment in the engineering 0 1 VALVE am. 2 SONNET 10 spaces is operated by either opening or closing 12 3 STEM. 4 DISk NUT 13 0 the valves. A valve isa device for stopping 5 DISK and/or controlling the flow of a fluid (liquid or 0 0 BONNET STUD 7 1 0ONNET STUD NUT 8 BONNET BUSHING gas) through as pipe or an opening. Valves are 19 9 OLAND installed in every piping system aboard ship. a 10 GLAND FLANGE 11 PACKING STOP RING You willfindtheminthefuelline,the 12 GLAND STUD 13 GLAND STUD NUT feedwater pipes, and the steam lines. In addition 14 SET SCREW 15 HANOWHEEL to the large valves which control the flow .of IC HANDWHEEL NUT 17 PACKING fluid in the lines, there are small valves which ID BONNET GASKET pipe the flow around the' larger ones. These '19 DISK WASHER small valves are called bypass valves which are used to equalize pressures. - .38.117 Valve, designs vary greatly to meet service Figure 10-14.Cross-sectional view of globe demands. Most valves are classified as stop valves stop valve. (globe, gate, plug, piston, butterfly, and needle Valves), check valves, or combination stop-check valves. 10 -14. -Globe valves are widely used, throughout Valves can be operated in various ways. the engineering plant for a variety of services. They may have hand wheels, air or hydraulic These valves may be used partly open as well as pistons, or they may be operated by gravity, or fully open or fully closed, and are suitable for by a solenoid. use as throttling valves.
STEP VALVES The moving parts of a globe valve consist of a disk, valve stein, and a handwheel. The stem, top valves are used to close off a pipe or which connects the handwheel and the disk, is ope g so that the contained fluid cannot pass threaded andfitsinto threads inthe valve bonnet. When you turn the handwheel the stem throw .Some valves can be closed partially to cut down or regulate the flow of fluid. moves up or down in the bonnet, carrying the disk with it The valve is closed by turning the The typical stop valve consists of the body, handwheel clockwise and opened by turning it an opening (port) through which the fluid flows, counterclockwise. a movable disk for ,closing this port, and some means to raise and lower the disk. In the closed The valve should never be jammed in the position, thedisk fits snugly into the port, open position. After a valve has been fully closing it completely. When the valve is open, -opened, the handwheel should be turned.toward the disk uncovers the port, allowing the fluid to the closed position one-half turn. Unless this is pass through. Each type of stop valve has a done, the handwheel is likely to freeze in the different mechanical arrangement for closing the open position, and it will be difficult to close port in the valve. the valve. Many valves have been damaged in this manner. Another reason for not leaving globe Globe Valves valves fully open is that it is sometimes difficult to tell whether a valve is open or closed. If a Globe valves generally derive their name valve is jammed in the open position, the stem from their body shape. (Other types of valves may be damaged or broken by someone who may also have globular bodies; hence, the name thinks that the valve is closed Ao,r1 tries to force may tend to be misleading.) A cross-sectional it open. Valves that are exceptions to the above view of a globe stop valve is shown in figure rulearecalledBACK SEATINGvalves.
128 134 Chapter 10 PUMPS, VALVES, ANti PIPING
The edge of the port, where the disk touches it, is called the valve seat. The edge of the disk and the seat are machined and ground together
YOKE SLEEV to form a tight seal. The rate at which the fluid NUT flows through the valve is regulated by the WHEEL pgsition of the disk. When the valve is closed, the disk fits firmly against the valve seat. When YOKE itis open, the fluid flows through thespace YOKE SLEEVE between the edge of the disk and the seat. Packing is placed in the stuffmg boxor space STEM that surrounds the valve stem and is held inplace by a packing glarid. With continueduse of the valve, the stem will graduallywear the packing away and a leak may develop. You can generally GLAND stop a slow leak by tightening the glanda turn or two. If this fails, pressure should be removed BONNET BUSHING from the valve and the packing shouldbe -renewed. PACKING _/ Y "BONNE9 Gate Valves
BODY BONNET BOLTS Gate valves (gg. 10-15) operateon the same principle as the gTobe valve, but they havea gate GATE instead of a disk. The port is the full size of the
BODY pipe and extends straight through the valve. The gate is connected to the valve stem aid is raised BODY SEAT or lowered by turning the handwheel. When the RINGS valve is in closed position, the wedge-shaped gate blocks off the port; in open position, thegate is GUIDE RIB drawn up into a recess in the,,top of the valve. Gate valves are used when\a straight-line flow through the valve is desirable. They donot work well as throttles because they tendto chatter.Therefore,gatevalvesareusually operated in the fully open or shut position. 7 They are often used in water lines. Plug Valves 11.317X Figure 10-15.Cutaway view of gate stop valve Plug valves (sometimes referred toas plug (rising stem type). cocks) are frequently used in gasoline and oil feed pipes as well as in water drain lines. The
ti ordinary petcock is a good example of thivalve. The body of a plug valve (fig.10-16) is Sometimes the operation of a back seating valve shaped like a cylinder with holesor ports in the will require that it be fully opehed. Whenever cylinder wall in 'line with the pipes in which the this is so, special instructions to that effect will valve is mounted. Either a 'cone-shapedor i be given. These valves are so designed that, when cylindrical plug, attached to the' handle, fits fully open, the pressure being controlled cannot snuglyintothevalve body. A hole bored reachthevalvestempacking,thereby through the plug is in line with thepo in the eliminating possible leakage past the packing. valve body. Turning the plug valve hdle 129 135 FIREMAN
O
( LUBRICANT SCREW
PLUG CHECK SUPPORT-SPRING VALVE NON-LUBRICATED VALVE fr
PLUG
*S. LUBRICATED VALVE 4
139.39X Figure 10-16.Plug valves.
(which is in line with the hOle in the plug) lines the opening in the valve seat before the needle up the hole in the pimp with.the ports in the actually, seats. This arrangement pefmits a very valve body so that fluid can Pass througi the ... gradual increase or,decreast- in the size of-the valve. The flow can be stopped by turning the" opening and, thus, allows more praise eontrol plug 90° (one-quarthr turn) from the open inf flow than can be obtained' with an ordinary position. globe valve.
Some plug valves are designed as three-way - Butterfly, Valves. or four-way selector valves. Three or more pipes.' are connected to a single valve in line with the same number of ports in the cylinder wall. Two Butterfly valves are used for liquid service or more holes drilled in they plug provide a only. The disk in this type valye is flat an varkty of passages through the valve. When a operated by turning the hand lever on the ste valve of this kind is located in a fuel line, the When the lever is positioned 90° to the piping liquid may be drawn from any one of two or the valve is fully open;lhe valve is in the ful three tanks by setting the handle in different closed-position when the lever is in4ine with the positions. piping.
Needle Valves CHECK VALVES
Needle valves are used to make relatively Check valves permit a flu" o flow through fine adjustments in the flow of fluid. A needle a line in only one direction...They have many valve has a long tapered point at the end of the uses, 'bothaboard ship and ashore: The air valves valve stem. This needle acts fs a disk. Because of in automobile tires, the valtrig in an ordina the long taper, part of the needle passes through watef pump, end the feedwater check valvekon
130 136 Chapter 10 PUMPS, VALVES, ANDPIPING DISK NUT
CAP
HINGE PIN
DISK
11.319X Figure 10 -17. Swing -check valve. 1 11.320 Figure 10 -18. Cutaway view of lift-checkvalve. a steam drum are examples of check valves. All of these valves open and close automat but Two similar stop-check valvesare shown in some have a handle or handwheel to 15ck them cross section in f(gure 10-19. As yoUcan see, the closed or to limit the size of the opening. flow and operating principles df thistype valve The port in a check valve may be closed bya very much resembles the check valve. However, disk, a ball, or a plunger. In some valves a spring the valve stem is long enoughso that when it is closes the valve, while in others the weight of screwed allthe- way doWn itholds the disk .the disk or ball holds the valve against theseat. firmly against the seat, thus preventingany flow The valve opens when thepressure on the inlet of fluid. In this position, the valveacts as a §top sideis greater than the pressureon the- outlet valve. When the stem is raised, thedisk can be side of the valve. It closes automatically when opened by pressure on the inlet side. Inthis the pressure on the inlet side is less than thaton position, the valve acts as a check valve, allowing theoutlet 'side.Figure10-17illustratesa the flow of fluid in onlyone direction. The swing-checkvalve andfigure10k18 shows td maximum lift of the disk is controlledby the lift-check valve. These valves are often installed posiVon of thevalvestem.Therefore,the' in drain lines, where it i portant that the flow position of the valve stemcan limit the amount be in only one dire of fluid passing through the valveeven when valve is operating as a check valve. &v.Stop -checkvalvesareusedinvarious STOP-CHECK VALVES locationsthroughouttheengineeringplant. Perhaps -"the As you have most° familiar exampleisthe seen, most valves can be so-calledboilerfeed-checkvalve,whichis classified as being either stop valvesor check actually a stop-check valve ratherthan a true valves. Some valves, however, can -functionas check valve. StRp-check valvesare used in many either a stop valve or as a check valve, depending 'drainlines; onkathedischargeside of "many on the position of the valve stem. These valves pumps; and as exhaust steam valves on auxiliary are known as STOP-CHECK VALVES. machinery. 6 131 137 a- I
FIREMAN
LIST OF FARTS =NY NO NAME OF MOS
I DODY OMR el OFT 4 ST QM rttracun 5 r,onv 7' 0 GLAND 7 yoxe, 7:tratino 0 STEM Harrow! to IraustLawcull11111M MEMGLAND COLT I 1&4311011111111111 11.1911PREM 15 4.,ney STUD NUT 10 RELIEF PLUG FEAT nino men 19 GLAND RANGE 20 MK! ou^mo at* COrZW 21 ARM HUT
11.321 FTOTo10-19.Stop-chock volvos.
THROTTLE VALVES to a single stem. Both valves open)1 or close at the same time whenever the handwheel is turned. A throttle valveisinst Iled in the main The ports and the disks are so designed that the steamlinejustahead ofhe engine.Itis steam tends to close one of the disk valves and .operated by a handwheel and can be opened or open theother.Figure 1040 illustrates the closed quickly for starting and stopping. These operating principle of a double-poppet throttle can also be set at any.in-between posit* valve. c) 2vestOiregulatethe speed of the engine. Unlike check The forces exerted on the disks of the valves,they areinstalledto that the steam double-poppetthrottlevalveresemble a 'pressure tends to close rather than open them. tug-of-war. The steam pushes down on top of The pressure in the main steam lines,of some one disk and up on the bottom of the other installations is 600 psi. The disk of a throttle disk. Like the rope in the tug-of-war game, the valve 6 inches across has an area of about 28 stem keeps the disks inthe same position, square inches. Therefore, the force exerted on relative to each other. the valve disk tending to keel; it dosed is 16,800 pounds (600 X 28). Throttle valves are designed RELIEF VALVES to equalizethisforce, so that they can be opened easily. 'Relief valvesareinstalledinthe steam, A double - poppet; throttle valve is two valves water, air, and oil lines, and on various units of in one. It has two ports and rwo disks attached machineryaboardship.Theyopen
132
138 Chapter 10PUMPS,
automatically when the pressure within the line O becomesteo high. Relief valves protect piping much esame asfusesprotect .electrical equipment and wiring in the home. There aie many types of relief valves. Most relief valves have either a disk or a steel ball acting against a coil spring. The disk-type relief valve in figure 10 -21 A consists of a valve body, a valve disk, and a stem. The steel spring pushes down .on the disk and keeps the valve closed. The force of the spririg is NISA11610 MN MN geperally adjustefl, by setting an adjusting nut on toof the spring! The inlet side of the valve is connected to the system to be protected. When the force on the bottom of the disk, 139.41 exerted by the pressure of the fluid in the line, Figure 10-21.Roliof valvoo. becomes greater than the compression of the spring, the disk is pushed off the seat, opening the valve. The valve outlet may be opened t6,the REDUCING VALVES atmosphere in compressed air or steam lines. When the valve is used to protect a pump, its The heating system and the galley operate outlet is connected to the suction line leading to on low-pressure steam. The source of..steam for the pump;. the excess fluid passes through the these systems is the boilers, whin are under relief valve, and back to the inlet side of the high pressures. Reducing valves are installed in pump. the steam lines to these systems, to reduce the The ball-type relief valve shown in figure preure.Thesevalveswillhold a constant 10-21B operates on the same principle as th pr ssure in the delivery lines, even if the boiler disk valve. The ball valve is generally used p ssure varies over a wide range. lube oil lines. The operating pressure is regulated Most reducing valves depend on a balance by adjusting the threaded plug (not illustrated) beeen the outlet or operating pressure and the which holds the spring in pre ure of a spring or compressed air in a sealed chat ber. Although some of these valves are quicomplicated, the principle on which they rate is easily understood. BOTTOM SURPACe AReA 20 SO. IN. The simplified reducing valve In figure 10-22 has a main valve, a piston, and a spring. The
HIGH LOW PRESSURE PRESSURE SPRING 600 PSI Panama'
, ARE 10 SC). IN. VALVE PISTON
J 139.40 139.42 Figure 10-20.Oporatingprincipleof a Figure 10-22.Tho operating principle of a simple douhio-poppot throttio valve. 139 reducing valve.
13.3 FIREMAN
compression of the spring pushes the piston to wilCutchattering and must remain tightly the left and opens the valve. When thesteam is closed after seating. turn.1 on, it passes through the open valve and builds up pressureintheoutlet chamber. Itisimportant that you understand- the Whenever theforceexertedonthepiston difference betweenboiler safety valves and becomes greater than the force exerted by the ordinary relief 'valves. The amount ofpressure spring, the piston moves to the right and closes required to lift a relief valve increasesas the the valvt valve lifts, because the resistance of the spring increasesinproportion tothe amount of During theoperation,theoutletsteam compression. Therefore, arelief valve opens c;31 pressure and spring force remain in balance with slightly at a specified pressure, dischargesa small the valve partly open. Any slight variation in amount of fluid, and closes at a lower pressure outletpressurewillupsetthisbalance. The which is very close to the pressure that caused it piston will move and increaseor decrease the to open. size of the valve opening and restore the original Can you see why relief valves will not do fbr outlet pressure. boilers? If the valves were set to lift at anything close to boiler pressure, tbe valves would be In some valves the spring is replaced bya constantly opening and closing, pounding the sealed chamber which contains compressed air. scats and disks and causing early failure of the The air pressure acts on a diaphragm instead of valves. Furthermore, relief valves will not rapidly on a piston. The valve can be set to maintain any discharge 'the large amount of steam that must desired pressure by adjusting the airpressure in bedischargedq4icklytobring theboiler the sealed chambej. Sometimes the diaphragm is pressure down to a safe point. Relief valves located between two chambers:one of them reseat very soon after they are opened.. (Figure opened to the inlet, and the other opened to the 10-23 shows a typical safety valve.) outletsteam. The action of the diaphragm operates a valve which in turn regulates the steam pressure on a piston connected to the PIPING main valve.In all reducing valves, the outlet pressure controls the rate at which the inlet Piping is used throughout the engineering steam is permitted to pass through the valve. spaces. One. piping system carries fuel from the service tanks to the furnace. A second piping SAFETY VALVES system supplies the boiler with feedwater. A third piping system carries steam from the boiler Each boiler is fitted with safety valves which to the engines and other points where itis allow steam to escape from the boiler when the needed. Still other systemsare used aboard ship pressurerisesabovespecifiedlimits.The tocarrysaltwater,freshwater,gasoline, capacity of the safety valves installedon a boiler compressed air, and certain gases.1,The nature of must be great enough to reduce the steam drum the substances carried in the pipes,as well as the pressure to a specified safe point when the boiler natureof the services performed, makes it is being operated at maximum firing rate with all necessary to use a variety of materials, sizes, and steam stop valves completely closed.Safety designs of piping and attached fittings. valves are installed-on the steam Mini and at the superheater outlet. PIPING DEFINITIONS Several different types of safky valvesare In routine operations aboard ship, there is used on naval boilers, but all'are designed to frequent misuse of the terms pipe, tubing, open and completely(POF whenaspecified pipingbystrikers and inexperiencednaval piessure is reached and to remainopen until a personnel. As a step toward correcting the specifiedpressuredrop" (BLOWDOWN) has misuse of these time terms, the following. occurred.Safetyvalvesmustclosetightly definitions are offered.
6 ..140 (N. Chapter 10-PUIVI S, VALVES, AND PIPING
ADJUSTING NUT
HAND LIFTING LEVER
SPINDLE
SPINDLE LOCK CLIP
DISK COTTER PIN ADJUSTING RING SET SCREW
'ADJUSTING RING DISK HOLDER
DISK INSERT NOZZLE RING
29.210 Figure 10-23.Steam drum safety valve (nozzle reaction type).
1. A PIPE is made of meal such as cast extrastrong. The outside diameter (OD) is the iron, wrought iron, steel, copper, or bra*. The same for each of the three wall thicknesses elf* size of a pipe is designated by its nominal inside any pipe with a given IPS dimension, while diameter (ID) in accordance with standard iron actual ID of these three pipes will differ. If the pipe size (IPS), expressed in inches or fractions ID measures more than )2 inches, the pipe is of an inch from 1/8 inch to 12 inches. Pipe is designated by its OD. designated in three grades or weights of wall For example, a 1-inch standard pipe will thickness as standard, extra strong, or double have an ID slightly over 1inc ile 1-inch
135 141 FIREMAN.
extra strong and 1-inch double extrastrong for transferring 600 psi, 850°F steam. The pipes will have lesser ID's because of their material of thefirst may be carbon steel; greaterwallthicknesses. An identical OD whereasthatofthesecond MUST be permits standardization in pipe dies and taps. molybdenum alloy steel, capable of resisting high temperature and pressure. 2. TUBING, unlike pipe, is designated for size. by its nominal OD dimension; specified for wall thickness in decimals of an inch; and joined PIPE FITTINGS by such methods as flanging, welding, soldering, or brazing. Because it has thinner wallg, tubing is A piping system can be made up by joining much more flexible than the thicker-walled pipe. individtallengthsofpipewithunions, Refrigeration piping systems are examples of couplings, elbows, or other threaded fittings. shipboard use of tubing. Piping systems may also be madeup by bolted flanges,weldings, _solderings,orbyflared. 3. PIPING is an assembly of pipesor couplings. tubing,andfittings,forming awholeor composite part of a system designed to transfer The water pipes in a home and some of the fluids (water, steamas, and oil).* low-pressurepipes aboard ship are fastened together' by THREADED fittings.Standard PIPING MATERIALS treadV pipe fittings are shown in figure 10-24.
Most of the piping systems aboard ship are made of steel, copper, brass, or a copper-nickel alloy. Steer is used for the steam and fuel oil lines. Copper tubing may be used for piping that carries fresh water, lube oil, and other materials. Nickel-alloy tubing has exceptional resistance to corrosion,andisused when resistanceto corrosion is an important consideration, such as in salt water and fresh water lines.
You will often hear the term "alloy" used in connection with various kinds of metals. A metal is said to be an alloy 1when it contains other metals in addition to the p1 rincipal one.
A chrome-nickel-steelalloyismade by adding chromium and nickel to the molten-steel whileitisbeing manufactured. A common stainless steel used aboard ship, which isa steel alloy, contains chromium and nickel. The alloys of steel, aluminum, and copper are widely used throughout the Navy.
.The piping materials must becarefully selected from specified standards approved by NAVSHIPS; not according to appearance. For example, the 7-inch steel tubing employed for transferring 400 psi, 650°F steam may look the 1i310X same to you as the 7-inch steel tubing employed Figure 10-24.Standard threaded pip fittings.
142 Chapter 10PUMPS, VALVES, AND PIPING
other NotySeas publications contain information ongasketsand packings. Aboard ship, tables which show the types of gasket and packing materialsapprovedfor various services are posted in the engineering spaces. Materials used for gaskets include pressed cork, asbestos, soft iron, Monel, metallic cloth, and hard fiber sheets. The type of gasket to be used depends on the pressures and temperatures to-which it will be subjected and in some cases, on the nature of the fluid being carried in the piping system. Packing is used to seal the area. around valve stems, revolving shafts, and sliding shafts. These units are designed with a space, known as a stuffing box, which surrounds the shaft or stem. When the packing has been placed in the stuffirg box, it is compressed by tightening a gland or 139.43 nutwhich screws up againstit.Such an Figure 10-25.Gasket insertion.. arrangement can be seen if you take an ordinary water faucet apart. The packing serves to keep the water from flowing up around the valve In high-pressure steam lines the lengths of stem. steel pipe are welded together into sections. A Packing materials in common use include flange is welded to. the ends of the sections. A woven asbestos and rubber; antifriction metal suitable gasket is inserted betweetk flanges, and woven with cotton thread and graphite; spun they are drawn tightly together 1giNtud bolts yarn;andsoftmetal,flax,andrayon which pass through the holes in the outer edges combinations. The-.type of packing to be used of the connection. (See fig. 10-25.) Tubing is depends on the service requirements. usually connected by flaredcouplings(fig. 10-26) or by soldering. STRAINERS GASKETS AND PACKING Strainers (fig. 10-29) are installed in almost all piping livErS to prevent the passage of foreign When leakage occurs in a piping system, it usually, occursat one of the joints. Many methods and materials are used to keep joints from leaking. Flanged joints in piping systems are made up with gaSkets to make a tight seal and thus to prevent leakage. (When the coupling is tightened, the gasket is compresSed and seals the joints.) Figure 10-27 illustrates various types of gaskets. Corinections in which there are sliding or rotating parts require packing material to seal the joints.
Figure10-28illustrates several kinds of packing. It is important that the proper gasket or packing material be used in each application. 11.310 NavShips Technical Manual, chapter 9950, and Figure 10-26.Tee for flared tubing.
C 137 FIREMAN
FLAT RING GASKET
B FIAT FULL-FACE GASKET
INSTALLATION CENTERING RING
(a) SINGLE-PLATE TYPE
CENTERING RING
a
(11) EXPANDING (DOUBLE-PLATE) TYPE D TYPICAL GASKET CROSS-SECTION
Figure 10-27.Fixed joint gaskets: A. Sheet asbestos gaskets. B. Plain-facedmetal gaskets. C. Serrated-faced metal gaskets. D. Spiral-wound, metal asbestosgaskets.
138 .-144 Chapter 10PUYPS, VALVES, AND PIPING
COILS
BRAIDED FLAX HIGH PRESSURE ROD GRAPHITE. LUBRICATED ASBESTOS
RUBBER -CO RED, DUek - WRAPPED, GRAPHITE LUBRICATED
ASBESTOS CLOTH AND RESILIENT RUBBER
RINGS
MOLD ED RINGS
BRAIDED COPPER
ASBESTOS, ALUMINUM,GRAPHITE AND
NEOPRENE COMPOUNDS .
PRESSED COTTON FABRIC
EXPANSION JOINT PACKINGS
WIRE-INSERTED ASBESTOS WIRE- INSERTED BRAIDED ASBESTOS, GRAPHITE- LUBRICATED 5.35X Figure 10-28 Type of packing. \145,139 =.41111 Jz tei ...... ,:x...... _ _ CI fa t.1,(10Imi era @ a.'
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1 . Chapter 10PUMPS, VALVES, D PIPING'
a valve and some device or arrangement which will cause the valve to open or Close, when necessary, to drain the condensate from the line without allowing the escape of steam. Steam traps are installed at the low point of a system' or below a machinery unitthat has "'to be drained. Drains are used to remove condensate MI while steam lines and steam-driven machinery are being warmed up. A drain usually consists of a section of piping and one or diore valves.
There are several types of steam traps in use on navalships: mechanical(fig. 10-30), thermostatic(fig.10-31), andimpulse(fig. 10-32).
You willfindadditional information on steamtrapsinchapter 9480 of NavShips Technical Manual. 11.325D Figure 10-30.A mechanical steam trap.
1
CAP
0-- VAPOR
VOLATILE LIQUID VOLATILE LIQUID a
SEAT BUSHING REPLACEABLE HERMETICALLY SEALED BELLOWS 4" 4
(a) TRAP COLD; VALVE OPEN (b) TRAP HOT; VALVE CLOSED
11.326X Figure 10-31.Thermostatic steam trap.
1 4 7 141 FIREMAN
CYLINDER STEM LOCK NUT CONTROL ORIFICE
CYLINDER ALVE SEAT CIRCULAR BAFFLE
TO HIGH PRESSURE INLET DRAIN SYSTEM
CONTROL VALVE ORIFICE DISK
CYLINDER STRAINER CIRCULAR BAFFLE FLANGE
VALVE VALVE SEAT DISK
38.126 Figure 10-32.Impulse steam trap.
rr
142 '148 0 CHAPTER '1 1
SHIPBOARD ELECTRICAL EQUIPMENT
Much auxiliary machinery and equipment irpn,offerlittleresistanceandarecalled aboard modem naval ships is run by--erdchiccity. CONDUCTORS. Regardlessof rate or rating,allpersonnel Incontrastto gopdconductors, some assigned to a ship will operate some electric substances, suchas wood, paper, porcelain; devicein / performance of hisduties. As a rubber, mica, and plastics offer a high resistance Fireman, you will probably use or operate to -"anelectriccurrentand are known as portablelights,electricdrillsandgrinders, INSULATORS. Electric circuits throughout the electric heaters,.....rittilatIon blowers and fans, ship Ware made up of copper wires covered with electric-drivenpumpk,andotherelectrical rubber or scune other insulator. The wire offers equipment. Therefore, you should know and littleresistancetothecurrent,whilethe observe ,all applicable safety precautions when insulation keeps the current from passing to the working with or around electrical appliances and steel structure of the ship. equipment. Definiteunitshave beenestablishedto We will not discuss the theories of basic measure electrical properties of conductors and electricity in detail in this chapter. However, we characteristics of electriccurrents. A brief will familiarize you with the different electrical review of these fundamentals of electricity is equipment aboard ship and withwliat the given in the sections which follow. equipment is designed to do. You will find additional information on the ELECTRIC CURRENT basicprinciplesof electricityinthe Navy training manualBasic Electricity,NAVEDTRA Current the rate at which electricity flocs 10086-B. through aand 6 ircuit, The practical unit, called the 'ERE (I) specifies the rate at which the electricurrent is flowing. AMPERE INTRODUCTION TO is a measure of thintensity or the number of ELECTRICITY electronspassinga point inas circuit each second. The flow of current can be compared to Various techniques and equipment which the flow of water through a pipe. apply principles of electricity require that you have some degree of theoretical knowledge, as ELECTROMOTIVE FORCE well as practical experience and skill, to operate them safely. Before an electric current can flow through a Electriccablescarry the electric energy wire,theremustbeasourceof- electric produced by the generators to the electric "pressure" just as there must be a pump to build motors whereitis expended in performing up water pressure before the water will flow work. through a pipe. This electric pressure is known All materialswill conduct electricity, but as ELECTROMOTIVE FORCE (emf) or voltage some of them offer more resistance than others. (E); the source may be a GENERATOR or a Metals such as silver, copper, aluminum, and BATTERY. ) 143 149 FIREMAN
If you increase the pressure on the electrons Alternating .current (a-c) is used aboard the in the conductor, a greater current will flow, just Navy's combatant ships. The advat4ages of a-c as an increased pressure on water inpipe will installations over d-c are lower cost, smaller increase the flow. units, and less maintenance.
RESISTANCE D-C GENERATORS AND EXCITERS Electrical resistance (R) is that quality of an electric circuit that opposes the flow of current A d-c generator is a rotating machine which through it. The unit of resistance is known as changes mechanical energy to electrical energy. the OHM. The essential parts of a d-c generator are the yoke and field windings which are stationary, WATT andthearmaturewhichrotates.IiIa-c generators, called alternator, the field rotates Power (P) is the rate of doing work. In a andthearmatureisstationary. To avoid direct-current (d-c) circuit, power is equal to the confusion,therotating .iembersofd-c product of the current times the voltage, or generators are 'called ARMA URES, and in a-c P = E X I. The practical unit of power is the generators they are called ROTORS. WATT, or KILOWATT (watts ÷ 1000). There isnodifferencebetweend-c generators and exciters. The exciter Isa' d-c generator which supplies direct current for an GENERATOR TYPES a-c generator. In the pasd-c ship's service AND DRIVES' generators were used abo d ship. At present, practically all ships hav 0-volt (60-hertz) a-4 The generatoris the heart of the ship's ship's service and emergency generators. The d-c electrical system. A large amount of electricity is generators used in Navy installations for ship's requiredaboardanyshipfordieproper service, or for exciters, operate att.either 120 provisionofair,water,andfood. volts or 240 volts. The amount of power output Communications between the various parts of a depends on thesizea esign of the d-c ship depend largely upon the availability of generator. electric power to operate the ship's announcing et. typical d-c generators ilustrated ;if .figure system, radio, radar, and lighting systems, as 114.Thearmatureissul'oortedOnball well as the training and firing of guns. bearings.Thefieldcoilwins ngscrea a magnetic. fieldthrough which the armature Since a generator runs at greatest efficiency windings are rotated to induce a voltage in the when generating or producingitsfull-rated armature windings. The current, 'driven by the power output; it is not practicable to have one inducedvoltage,iscirculatedthroughthe large generator running constantly at part load. commutator (on the armature shaft) and carried Therefore, two or more small generators are by the brushes (which ride on the commutator) installed 'aboard ship, depending on the specific to the external circuit. Part of the armature type ship. ent4is forced throufh ,the field winding to Another reason for installing two or mor increaseandmaintainthemagneticfield °generators aboard _ship is to ensure that, in the strength. event of damage to a generator, there will be
rough power and lights available until the GENERATORS , efectivegeneratorhasbeenrepaired.In addition, generators.ainstalled throughout the- The general construction a-c generators is engineering spaces of a s p so that the electricyl somewhat simpler than that of d-c generators. plant cannot be ,c1Fstroye y ones or two enemy The heavy current on a d-c generator has to pass shells or bomb hits. through the commutator and brushes. -An a-c
144
- .50, . chapter 11 SHIPBOARD ELECTRICAL EQUIPMENT'
jenerator does not have a commutator. The CAC SC Fara YIELD POD MOUNTING AND `heavy current on an a-c. generator is tqfken from Pozca IC LD COM! the stationary part or _stator windings. Ana-c generator has two sliprings which carrya DNUANCIS relatively small direct current that is suppliedby the exciter to the d-c winding of the rotor. END DELL An a-c generator, like a d-c generator, has magnetic fields and an armature. Ina small a-c C ONNUT ATOP generator the armature revolves, the field. is stationary, and no commutator is required. Ina large a-c generator the field revolves andthe irmature is wound on the stationary member,or stator. 73.161 Figure 11-1,A d-c generator. Theprincipaladvantagesofthe 'evolving-fieldgeneratorsoverthe revolving-armature generators are that:
1.The load current from the statoris connecteddirectlytotheexternalcircuit itho t using a commutator.
2.Only two sliprings are necessary to supply excitation to the revolving field. 3.The stator winding is not subjected to mechanical stresses that are due to centrikal force.
The a-c generators, or alternators, used by the Navy are divided into two classes:(I) A exTAYOR low-speed, engine-driven alternators, and(2) high-speed, turbine-driven alternators. The high-speed alternator may be either steam- or gas-turbine driven. The low-speed, engine-driven alternator (fig. 11-2) has a large °diameter revolving field,with many poles, and a stationary armature.' The stator(fig.I1-2A)containsthearmature windings. The rotor (fig.11-2B) consists of notow salient,or protruding,pales on which ,are mounted the d-c field windings. 1 Thehigh-speed,turbine-driv alternator (fig.11-3)isConnected either ictlyor through gears to a steam turbine. Thenclosed metal structure is part of a forced ventilation system that carries away the heat by circulation 139.43.0X of air through the stator (fig. 11-3A)and rotor * Figure 11-2.Low-speed engine-driven alternator. (fig. I L-3B). 4 145 f.,, 151 FIREMAN
SHIP'S SERVICE illustrated in figure 11-4. Although generator TURBINE- DRIVEN GENERATORS sets (turbogenerators) may be built differerittb all have the same arrangement of major parts. Ship'sservicegenwtorsareso named because they furnish electricity for the service of Turbines used for driving the ship's service the ship. Aboard most steam-driven ships of the generators diffrOrom other auxilial turbines in Navy, these generators are driven by turbines. that they usually operate on superheated steam. Large ships may have as many as six or eight These turbines are usually of the axial-flow, ship's service generators and from one to three multistage, geared type. The turbine exhausts to emergency diesel-driven alternators. a separate auxiliary condenser which has its own circulating pumps, condensate pumps, and air New constructiondestroyershavefour ejectors, Cooling water for the condenser is turbine-driven ship's service generators (two in: provided by theauxiliary circulating pump the forward engineroom and two in the after through separate injection and overboard valves. engineroom),and twosmallerdiesel-driven emergency generators, one forward and one 'aft. Superheated steam, is supplied to the ship's service generator turbine from either the main Thetypeofship'sservicegenerator steam line or a special turbogenerator line which commonly used aboard ships in the Navy is leads directly from the boiler. Aboard some ships,theturbinemayin theeventof condenser casualtybe discharged directly to theatmosphere,or to the main condenser when the main plant is in operation. Because the ship's service generator must supply electricityata constant voltage and frequency (hertz), the turbine must run ata constant speed even though the load will vary greatly.Constant speedis maintained by a speed-regulating governor. This turbine also has an overspeed trip,, which closes the throttle if the turbine overspeeds or if the speed-regulating governor fails to function; - aback- pressure trip, which closes the throttle if excessive exhaust pressure is built up; and a manual trip which may be used to close the throttle quickly if thereisdamage tothe turbine Or to the
11 generator. The shaft glands of the shit* service i `ASTATOR generator turbine are supplied with gland- sealing steam; the system is similar to that ased for mainpropulsionturbines.Otherauxiliary turbidesinnavaluseare ..selcicun,t if ever, A provided with gland-sealing systems.
Z' DIESEL-DRIVEN GENERATORS
noToR' Practically all Navy ships are equipped with diesel-driven'emergencygenerators.Diesel engines,rather than turbines and reduction gears, are most suitablefor this application 4. .139.44X4 becauseoftheirquickstartingability! Figure 11-3.High-speed turbine-driven alternator. Emergency generators furnishpower directly to
146
-1t 2 Chaper 11 SHIPBOARD ELECTRICAL EQUIPMENT
760-hW 60-Hz GENERATOR GAGE BOARD GEAR BOX TURBINE
',- THROTTLE VALE
CONDENSER 4
139.67 Ficura 11-4.-750-10V Turbine-Generator Sot.
the radio,, radar, gunnery, and vital machinery installation, the principle_ of operation is the equipment, through an emergency switchboard same. . and automatic bus transfer equipment. Detailedinformationconcerningthe The typical shipboard plant consists of two operation of diesel-driven generatorscan be diesel emergency generators, one foand and obtainedfromappropriatemanufacturers' one aft, in spaces outside the eng nerooms and technical manuals. firerooms. Each emergenty generator has its individualswitchboardandswitching arrangement for control of the generator and for SWITCHBOARDS distribution of power to certain vital auxiliaries and a minimum number of lighting fixtures in Switchboards consist of panels for munting vital spaces. the various measuring instruments, indicating The capacity of the emergency unit varies devices, and protective and regulating apparatus /with the size of the ship on which the unit is requiredto controltheoperationofthe installed.Reprdlessofthesizeofthe generatorsandthedistributionof electric
47 153 FIREMAN
00wer. A distribution switchboard is provided of theelectricalsystem. A typical power fig each generator or group of generators. distribution system in a destroyer consists of fotrr generatorstwo forward and two aft and Most Navy ships have from two to four two distribution switchboards, one with each ship'sservicegenerdtorswitchboards; small ships, such as destroyers, have two switchboards, two generators. All the necessary apparatus for whereas large ships may have as many as four to controlling each generator and for distributing eight switchboards. In many cases two or more itspowerisincorporatedinitsassociated switchboard. generators can feed one switchboard.
Most switchboards havetheequipment The forward ship's service generators and grouped to form a number of units. Each unit is distributionswitchboardarethecontrol switchboard. It is provided with instruments and complete. Bus bars .are used to tie each unit controls togetherto, form a switchboard. There are fortheaftergenerators.These Instruments andcontrolsarenecessary too bustie, generator, power distribution, and parallel the generators and equalize the load. An lightingdistributionunits.Each ofthese complete units has a separate front panel on the Automatic voltage regulator is mounted on each switchboard. Newer ships, Jhave transformers switch4oardtocontrol thegeneratorfield throughout the' ship with lighting distribution excitationand tomaintainaconstanta-c panels instead of lighting distribution units. A generatorvoltagethroughoutthenormal number of these units mounted on a common changes in load. base comprise a section. A switchboard may consist of a single section or 'of several sections, Two emergency diesel generator sets provide each complete in itself but connected by cables electric power for limited lighting and for vital to form a switch-gear group. This arrangement auxiliaries in the event of failure of the ship's of several,§m41 sections lessens the danger of service power. One unit is located in the forward shock, localiiti damage from fire, and provides emergency generator room and the other unit is for easy removal of damaged sections for repairs located in the after emergency generator room. The forward emergency switchboard is normally or replacement. energizedfromtheforwardship'sservice The two types of switchboard construction switchboard,andtheafteremergency are live front and dead front. The live front switchboard is energized from the after ship's switchboard is found only on very old ships service switchboard during normal operation. where low-voltage and d-c distribution systems D-c power distribution systems are in use on areused,andasinterior 'communications switchboards. The more cdmmon switchboard, some older ships that have large deck machinery loads. Th, se systems, which consist of the ship's shown infigure11-5,isusedforalla-c distribution systems. service gene and distributiontchboards, are similar to the a-c systems. On new ships, d-c (NOTE: The terminals are accessible on the live power is provided at the load with. rectifiers front type. In, the dead front switchboard, the when:required. meters and operating handles are mounted .on the panels, and all live parts are located within COMPONENTS, OF the panels.) A SWITCHBOARD..
GENER,ATOR AND Each switchboard includes one or more DISTRIBUTION SWITCHBOARDS"; units, a bus tie unit, a poWer distribution unit; lighting distribution units Or transformers, and Ship's service 450-volt, a-c switchboards are lighting 'distributionpanels.Largecircuit all of the dead front type. These switchkeprds breakers connect ship's service and emergency are built to provide efficient and safe operation generators to thpower distribution system.
-as 1 148
- 15 4 Chapter 11$H1PBOARD ELECTRICALEQUIPMENT They are also used on bus ties and shore isolate faulty circuits and toserve as overload connectioncircuits.In accordance with the protection. These circuit breakers electric load, smaller circuit breakers are a part o( are also the switchboard equipment. Circuitbreakers; installed on switchboards andon distribution rather thanfuses,are used in panels throughout the ship. circuits that require large amounts of current. Theycan bt) operatedfor an indefinite period, and theI Circuit Breakers action can be controlled with greateraccuracy' Overload circuit breakersopen automatically Circuit breakers (fig.11-6) equipped' with when the current (load)on the circuit exceeds a individual automatic tripping devices are used to preset value for which the circuit breaker isset.
77.254 Figure 11-5.Ship's service switchgeargroup No 15 section 1513.
149 155 FIREMAN
adjust (set) the voltage of the generator at any value within nominal limits. When additional loads are applied on the generator, there will be atendencyforthevoltagetodrop. The automatic regulator keeps the voltage of the generator constant at various loads.
Indicating Meters
All -the important switchboards aboard ship are provided with electrical meters of various types.Electrical meters, somewhat like gages and thermometers, show the operator what is taking place in the electrical machinery and systems. electrical meters are of two general types:installed meters (on switchboards) and portable meters. Some of the common meters that are used on switchboards are voltmeters, ammeters,kilowattmeters,andfrequency meters.
4 3 1. OPERATING HANDLE CHOWN 4. COVER SCREWS ELECTRIC ,MOTORS IN LATCHED POSITION C. 2. AMPERE RATING MARKER 5. BREAKER NAMEPLATE 3. MOUNTING SCREWS G. COTTER KEY HOLE Electric motors are used aboard ship ,to operate guns, winches, elevators, compressors, pumps, ventilation systems, and other auxiliary 77.241 machinery and equipment. There are many Figure 11-6.Circuit breaker. reasons for using electric motors: they are safe, convenient, easily controlled, and easily supplied with power. A motor changes electrical energy, produced Circuit breakers used with shipboard equipment by the generators, into mechanical energy. There are not susceptible to tripping under successive are gportant reasons for changing mechanical heavy shocks, such as those caused by gunfire. energy to electrical energy and back again to Circuitbreakersareusedonallrotating electrical machinery and feeders to vital loads, mechanical energy. One reason is that electric such as gunmounts and searchlights. cables can be led through decks and bulkheads In addition to overload relays, reverse power with less danger to watertight integrity than trip relays are provided on a-c generator circuit steampipesor mechanicalshafts.Another breakers. These units are designed to open in the reason is that damage to a steam line can cause steam to escape, resulting in personnel injury. If event of a power reversal. The units are mounted within the generator switchboard. an electric cable is used and a fault occurs, the circuitbreakerprotectingthecableopens Voltage Regulators automatically.
Voltageregulators; 'installedonthe D-C AND A-C MOTORS associated switchboards, are used for a-c ship's service and emergency generators. The voltage The a-c motor, smaller and requiring less regulator maintains the generator voltage within maintenance than the d-c motor, is extensively specified limits. The switchboard operator car, `used by t= Navy. The d-c motor, which is built
150 Chapter 11SHIPBOARD ELECTRICALEQUIPMENT
likead-c generator,is used mostly aboard Storage batteries are also used for auxiliary-ships and some small ships. emergency equipment aboard ship, for ship'sboats, and Most of the a-c motors used aboard shipare forklifts. The storage battery is usedas a source 3-phase,60-hertz,450-voltmotors.Tit ofelectricalenergyfor emergencydiesel induction motor is commonly used by theNavy. generators,gyrocompasses,andemergency Although most a-c motors haveone speed, a radio. number of motors with two speeds, thoseonventilationsystems,areinstalled Since you may act asa boat engineer, you aboard ships. should be familiar with safety precautionsto be observed when you work aroundbatteries. Batteries must be protected from MOTO1 1 CONTROLLERS salt water, whichcanmixwiththeelectrolyte(acid solution) and give off poisonous Controlling devices fumes. Salt are used to start, stop, water in the electrolyte also setsup a chemical speed up, or slow down motors. In general, these reaction which will ruin the battery. Ifthis ever controllers are standard equipment aboardship \ occurs, notify the electricshop immediately. andareeithermanual,semiautomatic,or automatic.Theyare dripproof and shock Storage batteries, whell being charged,give resistant. In some installations the controllers off a certain amount of hydrogengas. Battery are operated by remote control, with the switch compartments should be at a convenient location. wellventilated to discharge this gas to the atmosphere.Flames or These motor control devices (controllers, sparks of any kind, including lightedcigarettes, master switches, and electric brakes) protect the should never be allowed in thevicinity of any equipmenttowhichtheyareconnected. storage battery that is being charged. Whenthe Controllers provide protective and governing battery is low or does not performproperly, the features for every type of shipboard auxiliary. boat engineer should notify theElectrician's To govern the controllers themselves, chaster Mate (EM) so that the faulty conditioncan be switches of various types are installed. Electric corrected promptly. brakes are used to bring a load to rest,or to hold it at rest, when electricpower to the motor is cut off. Aboard ship, electric brakesare used PORTABLE EQUIPMENT primarily on hoisting and lowering equipment such as cranes, winches, and windlasses. Aboardanyshiptherewillbesmall electric-powered equipment, suchas portable Most controllers function simply tostart or electricdrills, hand lanterns, small ventilation tostopauxiliary machinery,butsome blowers, and handtools. SAFETY iswearing controllers also provide for reversal of direction rubber gloves and protective safetygoggles when ormultispeedoperation. Motor controllers, you work with metal-cased portable electric some timescalledstarters,haveoverload tools. protective devices to prevent burningout the motor. Most controllers cut out automatically BATTLE LANTERNS when the electric power fails, and they haveto be restarted manually. . Relay-operated hand lanterns (fig.1 l-7A) usually called battle lanterns,are powered by dry cell batteries. Hand lanternsare provided to BATTERIES give emergency light when the ship'slighting systems fail. These lanterns are placed in Aboard ship, batteries are one of the spaces sources where continual illumination isnecessary, such of electricity for emergency and portablepower. as machinery spaces, control rooms, essential Drycellbatteriesareusedprimarilyfor watchstations,battledressing stations, and flashlights, hand lanterns, and test equipment. escape hatches. All auxiliary machinery with
151 157 FIREMANa
1-EANTERN D HAND LANTERN (RELAY OPERATED) I") (MANUAL OPERATED)
C PORTABLE FLOOD LANTERN
7. 77.47 '47 Figure 11-7.Special lights.
152
- Chapter 11-- SHIPBOARD ELECTRICALEQUIPMENT
gage boards should be provided with a battle maintenance workisbeing done or when lantern to illuminate the gage board in theevent machinery repairs are being made. of a casualty. The battle lantern shouldnot be The portable extension light and cord should removed from its mounting bracket except in an be in good condition. The cord should'be free emergency. DO NOT use It as a flashlight. rom cuts or damaged areas. The light and cord The relay control boxes for battle lanterns s tuld be free from moisture, oil, andgrease. are connected to the emergency lighting supply Do not lay extension cordsacross decks & circuit (or to the ship's service lighting circuit)in other places where they.may be damaged. If which the lantern is installed. Ifpower in the possible, cords should berun overhead and tied circuit fails, the relay opens and the batteries in place. Also, keep rubber cords light the lantern. away from hot steam piping as well as away from oiland paint. Hand ,(battle)lanternsare capableof Avoid running an extension cord througha operatingforapproximately10 continuous watertight hatch or door. hours (or the equivalent) before the lightoutput An extensionlight ceases to be useful. should be returned promptly to the tool issueroom or electric shop Similar hand lanterns (fig. 11-7B) whichare after the work for which it Was usedhas been NOT connnectedtorelays,areinstalled finished. The light should be clean, dry, throughout the ship to provide illpmination in and in goodcondition.Defectiveextensionlights stations which are manned occasionally.These (including lightswithout guards) should be Lanterns are manually operated. If used in an brought immediately to the electric shopfor emergency, the manually operated hand lanterns repairs. should always bp1 RETURNED TO THEIR ORIGINAL LOCATION. PORTABLE TOOLS SEALED BEAM LIGHTS Proper care and precautionarymeasures should be taken in handling and workingwith Sealed beam lights (fig. 11-7C),a type of portable tools such as electric drills andgrinders. flood lantern, are used to give high-intensity Protective goggles must ALWAYS beworn when illuminationin daT agecontrolorother tools such as wire brushes and grindersare used. emergency repair work. These units consist ofa There is an inherent danger whenyou work sealed beam lightsimilar tothat used for with portableelectric tools because of the automobiles. The sealed beam light, poweredby possibility of electric shock. Electrician'sMates four small wet cell storage batteries, ismounted are required to make weekly tests of all portable in the battery case and fitted with a handle for electrical tools to ensure .that theyare safe to convenience in carrying. A sealed beamlamp use. Portable tools in use on Navy shipsare will operate for the equivalent of 3 continuous provided with a grounded plug anda ground hours before the battery requires recharging. wire connected to the metal partof the tool. When the battery is at full charge, the beamhas Grounded receptacles are installed throughout an intensity which is similar to that of the the ship. The cords for portable electrictools headlight on an automobile. At the endof 3 contain three conductors; the thirdconductor is hours the light, output will gradually dropto used to ground the portable tool about to the ship. one-half itsoriginalbrilliance. These Theseprecautionsaretakento sealed beam lights are normally stored prevent in the dangerouselectricshocktooperatorsof damage control repair lockers. portable tools. PORTABLE EXTENSION LIGHTS SHIPBOARD ELECTRICAL SYSTEMS Portable extension lights are _widely used AND- CONNECTIONS aboard ship, especially in the engineeringspaces. Only approved extension lightsare to be As a Fireman, you should be familiar used. with Adequatelightingisnecessary when the power distribution systems,the lighting
153 159 FIREMAN
distributionsystems,andshorepower distribution boxes. The feeder distribution box, connections which have been described briefly which is similar to the power distribution panel, in this manual. You will find greater detail on. has only a few branch circuits. The distribution this and other shipboard electrical equipment in boxes carry power directly to. the actual load chapter 9620, Nav Ships Technical Manual. circuits.
POWER DISTRIBUTION SYSTEMS SHORE POWER CONNECTIONS
The power distribution system connects the Shore power connections are installed at or generators, which furnish electric power, to the near suitable weather deck locations to which power-drivenequipment installedthroughout portable cables from the shore, or from a ship the ship. From the generator switchboards, a alongside, can be connected. Power Can be 4.,distribution system consisting of feeders, mains, suppliedthroughtheseconnectionstothe submains, load center panels, and distribution switchboard when ship's service generators are boxes carries power to every part of the ship. not in operation. The most important auxiliaries are supplied with normal,alternate,andemergencyfeeders, through automatic bus transfer units, each with ELECTRICAL SAFETY aseparatesource of power. Casualty power PRECAUTIONS systems areinstalled aboard ship to provide electrical connections when both ship's service There are certain safety precautions which and emergency electrical systems are damaged. should be observed by those who work with or around electrical appliances and equipment. LIGHTING DISTRIBUTION SYSTEMS Following are some of the most common electrical safety precautions which all shipboard Lighting distribution systems are necessary personnel are required to follow: not only tolight the ship but also to assist personnel incontrollingdamage.Aboard Do not attempt to maintain or repair combatantshipstwolightingsystemsare electric equipment. Leave the electrical work to installed: ship's service lighting and emergency the Electrician's Mates and IC Electricians. lighting. The ship'sservice lighting normally Observeandfollowallpertinent supplies all lighting fixtures. Emergency lighting instructions and electric warning signs aboard circuits are supplied to vital machinery spacqs, ship. the radio room, the combat information cente'1, and other vital spaces. The emergency lighting Observe all safety precautions regarding system receives power from the ship's service portable electric lights and tools. (Rubber gloves generatorsbut, if normal power islost, the and goggles.) emergency system is automatically cut in on the emergencygenerators.Lightingdistribution Ren) ember that120-volt electricityis systemsaresimilartopowerdistribution very dangerous, especially aboard ship. systems,exceptthatthey(I)aremore numerous, (2) have lower voltages (120V), and Do not touch or operate an electrical (3) have smaller panels and cables. switch which has a warning tag attached to it. Lighting distribution requires a variety of Donotgobehindelectrical panels and distribution boxes to connect their switchboards. loads with their power supplies. High-voltage feeders from switchboards are stepped down Do not touch liveelectric wires and from 450Vtoapproximately 120Vby fittings. transformerswhichareconnectedto distributionpanels.CircuitA emerging from Do not remove steamtight globes from distributionpanelsareconnectedtofeeder lighting fixtures.
154
4 160 Chapter 11SHIPBOARD ELECTRICALEQUIPMENT Do not remove battle lanterns &Omtheir When you repair equipment locations. thatis drivenbya motor,haveanelectrician Z disconnect the circuit and tag itas out of Do not use manually operatedhand commission. battle lanterns for unauthorizedpurposes. Each person should have his own flashlight. Do notstartoroperateelectric equipment when flammable Do not use electric cables to hoistor vapors are present.. support heavy weights, and donot use the wireways for storage. Take time to learn the electrical safety precautions that are applicableto your assigned Do notpermitwatertogetinto duties and duty station, whetheritbe the electrical equipment. fireroom, engineroom, electricshop, or other duty assignment. (A thoroughunderstanding of Remember that a flame, spark,or lighted electrical safety precautions willhelp prevent cigarettecan cause adisastrousbattery injury to yourself and damageto equipment explosion. which you may be calledupon to operate.
Rememberthatelectrolytefroma storage battery can cause If you are everin doubt about the severe burns and can operating conditionof electrical equipment, `-damage equipment and clothing. CALL AN ELECTRICIAN.
161
155 CHAPTER 12
INTERNAL COMBUSTION ENGINES
Mostoftheauxiliarymachineryand t6NITION PRINCIPLES equipmentaboardlargeNavy shipsutilize electric motors as prime movers. This chapter Thegasolineand, dieselenginesdiffer dealwrimarily with internal combustion engines principally in that the gasoline engine has a in which a mixture of air and fuel serves as the carburetor and a spark ignition system. The fuel working fluid. and air for the SPARK IGNITION (GASOLINE) ENGINE ismi inthecarburetor.This Internalcombustionenginesareused mixture is drawn ito the cylinders where it is extensively in the Navy, serving as propulsion compressed and igni an electric spark. units in a variety of ships and boats. Also, T e CO-11 IGNITION type engine internal combustion engines are used as prime is com only known as a DIESEL ENGIN 'E. The forauxiliary movers,orenergizingunits, diese, engine ' takes in atmosphericair, machinery.Inmost shipboardinstallations, compre ses it, and then injects the fuel into the internalcombustionenginesareofthe cylinderThe heat generated by compression RECIPROCATING type.Inrelativelyrecent ignites the ei;.hence, the term "compression years, GAS TURBINE engines have also been ignition" issed h,-Vdiesel engines. placed in Navy serviceas power units. The discussion which follows will deal primarily with OPERATING CYCLE reciprocating engines. Allreciprocalg engines have a definite cycle of operationtomize the fuel, get it into RECIPROCATING ENGINES 0 the cylinders, ignitand burn it, and dispose of thegasesof combustion.Allreciprocating The internal combustion engines (diesel and internal combustion engines operate on either a gasolineengine)withwhich youwillbe 2-stroke or a 4-stroke cycle. A stroke is a single working are machines that convert heat energy up or down movement of the piston, or the into mechanical energy.Diesel and gasoline distance a piston moves between limits of travel, engi,pes are of the reciprocating type. Eachpistonexecutes two strokes for each revolution of the crankshaft. The number of The general trend in Navy service is to install piston strokes occurring during any one series of dieselenginesratherthangasolineengines, operations (cycle) is limited to either two or unlessspecialconditionsfavortheuseof four, depending on the design of the engine. gaiokineengines.Smallboatsusedin conjunctionwithairplanefacilitiesare In 4-STROKE CYCLE engines each piston frequentlypoweredwithgasolineengines goes through for strokes and the crankshaft because the available fuel supply is gasoline. In makes two revolirtie.ris_to=-compete one cycle. !dition, gasoline engines (P-250 pump) are used Each piston delivers power during one stroke in lme installations because of their small size four, or each piston makes one power stroke for .tck of suitable diesel engines. each two revolutions of the crankshaft.
.156 12 -- Chapter 12INTERNAL COMAUSTIONENGINES
during this stroke. The air whichentered the cylinder during the intake stroke iscompressed into the small space above thepiston. The volume of this air may be reducedto less than 1/16 of what it was at thebeginning of the stroke.
The high pressure, which results fromthis great.reductioninvolume,raisesthe temperature of the air far above the ignition point of the oil. When the pistonnears the top of the compression stroke, the chargeof fuel is B forced into the cylinder through theinjection valve.The airwhich has been heated by compression ignites the fuel. tirN During the POWER STROKE, indicatedin C of figure 12-1, the inlet and exhaustvalves are bothclosed.Theincreaseintemperature resulting from the burning fuel greatlyincreases the pressure on top of the piston. Thisincreased pressure forces the piston downward and rotates the crankshaft. This is the only strokein which power is furnished to the crankshaft by the piston.
54.19 During the EXHAUST STROKE, shownin Figure 12-1.The 4-stroke diesel cycle. D of figure 12-1, the exhaust valve isopen and the intake valve remains clesed.The piston moves upward, forcing the bailed gases out of Let us take one cylinder ofa diesel engine the combustion chamber throughthe exhaust and trace its operation through the four strokes valve. This stroke, which completes thecycle, is that make up a cycle. (See fig. 12-1.) The engine followed. immediately by the intakestroke of parts showninthisfigureincludeonly a the nexi cycle, and thesequence of events cylinder, a crankshaft, a piston and connecting- continues to repeat itself. rod, and theintake and exhaust valves. To simplifythe diagrams (A throughD), the The 4-stroke cycle gasoline engineoperates valve-operating mechanism and the fuel system on the same mechanical, or operational, cycle have been omitted. as the diesel engine. In the gasoline engine,the fuel In part A of figure 12-1 the intake valve is and air are mixed in the carburetor,and the open and the exhaust valve is closed. The piston mixture is drawn into the cylinders throughthe is moving downward and drawinga charge of air intakevalve. The fuel-air mixture is ignited into the cylinder through the open valve. This near the top of the compression stroke byan, portion of the cycle during which the piston is electricsparkwhichpassesbetweenthe moving downwardis.calledthe INTAKE terminals of the spark plug. STROKE. When thecrankshaft has rotated to the The principal difference in the cycles of position shown in 11 of figure 12-1, the piston operation for diesel and gasoline enginesinvolves has moved upward, on the COMPRESSION the admission of fuel and air to thecylinder. STROKE, almost to the top of the cylinder. While this occurs as one event in theoperating Both the intake and exhaust valvesare closed cycle of a gasoline engine, it involvestwo events
157 163 -FIREMAN
indiesel engines. There are six main events taking place in the diesel cycle of operation (intake of air, Compression of air, injection ,of fuel,ignitionandcombustionofcharge, expansion of gases, and removal of burned gases), and five main events in the cycle of a gasoline engine (fuel is not injected in a gasoline engine). TWO-STROKE CYCLE diesel engines are widely used by the Navy. The Navy ')uses some gasoline engines that operate on the 2-stroke cycle; they are used principally to drive portable pumps/ Every second stroke of a 2-stroke cycle engine is a power stroke. The strokes between are compression strokes. The intake and exhaust fundtions take place rapidly near the bottom of each power stroke. With this arrangement there is one power stroke for each revolution of the crankshaft, or twice as. many as in a 4-stroke cycle engine. The steps in the . operation of a 2-stroke cycle engineare shown infigure12-2. The cylinder shown ,has an exhaust valve but no intake valve. (Other designs have both intake and exhaust ports and include no valves.) The air enters the combustion chamber through ports (openings) in the cylinder wall; these ports are 54.20 uncovered by the piston as it nears the bottom Figure 12-2.The 2-stroke diesel cy of each stroke. In A of figure 12-2, the piston is moving upward on the compression stroke. The exhaust are carried out through the exhaustlve. This valve and the intake ports are closed, and the scavengingoperationtakesplacealmost pistonis compressing the air trapped in the instantly and corresponds to the intake and combustion chamber. At the toR of the stroke, exhaust strokes of Ow 4-stroke cycle. with the piston in the position shown in B of You might expect a .2-stroke cycle engine to figure 12-2, fuel is injected (sprayed) into the develop twice as much power as a 4-stroke cycle cylinder and then ignited by the hot compressed engine; however, it does not because a certain air. percentage of the engine's power is required to In C of figure 12-2,\the piston is moving drive the blower. Nevertheless, 2-stroke cycle downward on the power stroke. The exhaust dieselenginesgiveexcellentservice.Small valve is still closed anthe increased pressure, gasoline engines operating on the 2-stroke cycle resulting from the bumikg fuel, forces the piston principle operate satisfactorily, but the larger downward and rotates the crankshaft. sizes are less popular. As the piston nears the bottom of the power stroke, shown in D of figure 12-2, the exhaust valve opens and the piston continues downward DIESEL ENGINES to uncover the intake ports. Air delivered under pressure by a blower or from the crankcase (in a The diesel engines used in small boats look gasoline engine)isforced into thecylinder very much like the gasoline engines used in an through the intake ports, and the burned gases automobile. Each cylinder has an injector to - 158 164 Chapter 12INTERNAL COMBUSTIONENGINES admit fuel to the cylinder at the sd proper time. sleeve called a cylinder liner. Theupper end of The injector may alsoserve as the higl&pressure the cylinder is covered by a cylinder head. pump. Some engines have a high pressure pump withahydraulicheadwhich resemblesa The pistons are connected to the crankshaft distributor. The lines carry the highpressure fuel by connecting rods, which transmitpower from to the injector in the same order Ss the firing the pistons to the ,crankshaft and converttheir order. On the gasoline e gine, the carburetor reciprogating motion to the rotary motion of provides the proper mixtte of gasoline and air the pfankshaft. The rodsare joined to the for the cylinder. In mostf the 1-cycle.gasoline ns by pistonpins (wrist pins) and are 'engines in use by the Na, the oil is mixed with nected to the crankshaft by connectingrod the gas to provide lubrication for thebea gs arings. (See fig. 12-3.) Ringson each piston azkikpistons. Most boat engines ha,eta s water ovide a seal between the Pigton-and the heatexchangerinsteadof thecoentional c linder wall. As the piston moves up and down, radiator. Although different makesa models rings press' against the cylinder wall, thus of diesels vary widely, they all havehe same pr ventingthe air or gases from passing down i essential parts. k to the crankcase or the oil in the crankcase rom working up past the rings. In addition'to POWER SYSTEM thepressure of 'therings, compression and corcibustionpressure betweenthering and The main workingparts ofthe engine piston push the rings against the cylinderwall. transmitpower fromthecylinderstothe The rotating force of the crankshaft-' is used driveshaft. These ,parts include the cylinders, to drive such items as reductiongears, propeller pistons, connecting rod, and the crankshaft.The shafts, generators, and cylinders of most marine engines pumps. During three of are contained the strokes of a 4-stroke cycle engine, therotary in a single block or crankcase ofiron. Each motion bf the crankshaft is moving the cylinder is lined with a special hardened steel piston up and down A. -
CONNECT 1NG PISTON PIN CAP ROD BEARING CAP CONNECTING ROD OIL SEAL SADDLE SADDLE SPRING
WAS HE
PISTON PIN CONNECTING PISTON 1 ROD j3OLTS COMPRESSION en CONNECTING ROD PISTON RINGS, PISTON PIN PISTON PIN BUNING
OIL CONTROL PISTON RINGS PISTON PIN CAP
n02 of,
76.69 Figdre 12-3.Piston and conretingrod parts.
0- 159 165 1 FIREMAN
VALVE MECH IISM tight fit in the exhaust openings (ports) in the cylinder head and are held in the closed position The valves are opened by the action of a by the compression of the valve springs. The camshaft, driven by the crankshaft through a rocker arm and tuidge transmit the reciprocating trainofgears,oragear andchain-drive motions of the cam roller-to the valves. mechanism. The camshaft extends the length of the engine and carries one or more cams for each . In figure 12-4A the cam roller is riding on cylinder.Theshaftiscylindricalwith the base circle of the cam and the valves are irregular-shaped cams. Each cam is circular on closed. As the camshaft rotates, the cam lobe or one end and has a LOBE (NOSE) on the other nose rides under the roller and raises It to the endwhichgivesthatendanegg-shaped position shown in figure 12-4B. When the roller appearanceasshowninfigure12-4B. The is lifted, the arm rotates around the rocker shaft circular part of the cam is called the cam flat or and the opposite end of the arm is lowenbd. This base circle. action pushes the bridge and valves down against Thecamshaftgivesanintermittent the pressure of the valve springs and opens the reciprocatingmotionas itrotates.A, cam valve passagfs. follower br roller,, riding on the rotating cant, is lifted each' time the lobe or cam nose comes On some types of engines, the camshaft is around. located near the crankshaft. In these designs the The valve mechanism of a 2-stroke cycle action of the cam roller is transmitted to the diesel engine is shown in the cutaway views that rocker arm by a push rod. In some engines, the appear infigure12-4.This engine has two valves are inverted and are located in recesses at exhaust valves which are opened at the same the side of the cylinders. In this arrangement the time by the action of a single cam. They make a valve stems may ride directly on the cams, or J they rimy be separated by a short steel shaft and CA ND. At. tn.., A Al 40.01 ttttt (Dv. 40Ca.1 .01 roller called'a tappet assembly. The camshaft must _betimed with the crankshaft so that the lobes will open the valves in each cylinder at the correct instant in the operatingcyeI Inthe2-strokecyclethe exhaust valves are opened for only a short time near the bottom of the power stroke to Rermit the burned gases to ekape. Since the-.c cle is completedinonerevolution,thecamshaft rotates at the same speed as the crankshaft.
A The 4-stroke cycle engine has an intake and an exhaust valve in every cylinder.-Each valve is operated by a separate cam. The intake valve is held opeh 'during the intake stroke, and the exhaust valveisopened during the exhaust stroke. Since two revolutions of the crankshaft are necessary to complete a 4-stroke cycle, the. camshaft of these engines turns only half as fast as the crankshaft
AIR SYSTEM
, 139.46 Figgre 124:--Cutaway of a cylinder head, shovving the In "the 4-stroke. cytte en ne, the air enters valve-operating mechanism. the cylinders through. the iake valve. As each
160
9 166 Chapter 12INTERNAL COMBUSTIONENGINES pis* ton* moves downward on the intake stroke, stroke is called the COMPRESSIONRATIO. the volume in the combustion chamberincreases Compressing the air to andthe 1/16 of its original pressuredecreases.Thenormal volume would representa compression ratio of atmospheric pressure then forces the air into the 16 to 1. cylinder through the intake valve. As the compression ratio is increased,the Since the 2-strode cycle engine doesnot go temperature of the air in the cylinder increases. through an intake stroke,a means must be... Current gasoline engines operate atcompression provided to force air into the cylinders.The, air ratios between 8to 1 and11to1, but enters through intake ports, uncovered when the compressionratiosofdieselengines range piston approaches the bottom of thepower between 12 to I and 16 to 1. Thismeans that on stroke. (See fig. 12-S.) Since the exhaust valves the compression stroke ofa diesel engine the air areopen when the intake ports are being is compressed to arange of 400 to 600 psi; uncovered, the incoming air forces theburned which results in a temperature rangingfrom gases out through the exhaust valves and fills the 700° to 800° F. However, when2thefuel is cylinder with a supply of fresh air. injected Into the cylinder and beginsto, burn, the pressure may increase tomore than 1500 psi On the compression stroke, theexhaust and the temperature may riseas high as 1800°F. valves are closed, the intake portsare covered, and the air is trapped in the cylinder.The rising pistoncompressestheairandraisesits FUEL SYSTEM temperature. By the time the piston reaches the top of the stroke, the volume of the combustion The fuel system of the diesel enginedraws chamber has been greatly reduced. The relation fuel oil from the service tank and between the volume of the cylinder with injects it into the the engine cylinders. Figure 12-6 shows theunits piston at the bottom of its stroke and the found ina typicalfuel system of the unit cylinder volume with the piston at thetop of its injector type. The fuelpump draws the fuel oil from the tank througha primary filter and delivers it under lowpressure to the injector by way of the secondary- filter.The injector, operated by a rockerarm, meters, pressurizes, and atomizes the fuel as it is injectedinto the combustion chamber. The outlet line carriesthe * excess fuel oll-from the injector back to the fuel tank. In some installations,a transfer pump is installed between 'the tank and 111=611.1111111111* a_ I the primary filter. In other installations, the injectionpump and injection nozzlesare separate units instead of a combined unit, as shown in figure12-6. A diesel engine will not operate efficiently unless clean fuel is delivered to theinjector or injection nozzles. As the fuel oil is pumpedinto the fuel tanks, it is strained througha fine mesh screen.Thelargerparticlesof thesolids suspended in the fuelare trapped in the primary *screen. The secondary filter separates the finer particles of foreign matter wftichpass through the primary filter screen. The final filtering takes place within the injector. Mostfilters have w 75.151 Liain plug for removing thewater, sludge, and Figure 12-5.ml-A 2:stroko-cyclo enginecylinder with other foreignmatter. Thefiltershould be the piston at the bottom all thepower stroke. drained once each 'day.
161 167 0
FIREMAN
injectthe same amount .4fuelinto every
CRIVT PR tPl PIPS cylinder. Thean-TOT\I toffuelinjectedintothe PR to. v cylindersoneachstrokeiscontrolledby TO mar RAPIPaD rotating the plungers of a unit injector. The throttle, which regulates the speed of the engine, auer01.0 is connected to the injectors through a suitable linkage. A change in the throttle setting rotates the plungers and varies the amount of fuel injected into the cylinders on each stroke. ISCONORAY
PAL PPP LUBRICATION SYSTEM
Thelubricationsystemofaninternal combustion engine is very important.If the PIPS. 111uRT MP. *WIWI, 10 PUP, lubricating system should fail, not only will the engine stop but also many of the parts are likely to be damaged beyond repair. Therefore, when lubrication failure occurs, the engine can seldom be run again without a major overhaul. The lubricating system delivers oil to the
PRUARIP PUP. moving parts of the engine to reduce friction PM VON ISPIR181) and to assist in keeping Them cool. Most diesel PUP. ?ANN andgasolineenginesare equippedwitha pressure lubricating system which delivers the oil under pressure to the bearings and bushings and also lubricates the gears and cylinder walls. The oil usually reaches the bearings through passages drilled in the framework of the engine. 2.67X The lubricating system of a typical diesel engine Figure 12-6.The fuel supply system of a General is shown in figure 12-7. Motors portable diesel engine. Many methqAs of lubleating the individual parts of eachtypeof engine are in use in the different engine models. Generally speaking, the There are many methods of fuel injection. oilisfedfrom the main gallerythrough and just as many types of injection pumps and individualpassagestothe main crankshaft nozzles. The unit injector shown in figure 12-6 bearings and one end of the hollow camshaft. consists basically of a small cylinder and a All the other moving parts and bearings are plunger, and extends through the cylinder head lubricated by oil drawn from these two sources. to the combustion chamber. A cam, located on The cylinder walls and the teeth of many of the the camshaft adjacent to the cam that operates gears are lubricated by oil spray thrown off by the exhaust valves, acts through a rocker arm the rotating crankshaft. After the oil has served and depresses the plunger at the correct instant its purpose, it drains back to the sump to be in the operating cycle. used again. When the injector plunger is depressed, a 'IThe oil pressure in the line leading from the fine spray of fuel is discharged into the cylinder, pumptotheengineisindicatedona, through small holes in the nozzle. The amount Bourdon-type pressure gage. A temperature gage of fuel injected on each stroke of small boat in the return line provides an indirect method engine fuel pumps is very small. The smooth for indicating variations in the temperature o' operation of the engine depends to a large the engine parts. Any abnormal drop in pressure extent on the accuracy with which the plungers ,or rise in temperature should _be investigated at
162 168 Chapter 12INTERNAL COMBUSTION ENGINES
12 0 Ct ti ARM
PUSH ROO
C 03 0 E.. Jai OIL PRessuria ciaGe\ PISTON PIN CONNECT= Roo U 11. b
CAMSHAFT OE AR
MAIN OIL LINE
THRUST DUTTON1.3.*
V ALVC LIFTER CAMSHAFT
CRANKSHAFT i±
CRANKSHAFT GEAR
OIL PAN
OIL LEVEL OIL PUMP
OIL INLET SHIELO
OIL INLET SCREEN
. 29.96 Figure 12-7.Basic units and oil passages ofa pressure feed lubrication system.
once. Itis advisable to secure the engine until to flow back into the sump. All of the oil from the trouble has been located and corrected. the pump passes through the strainer, unlessthe All of the engine parts are lubricated with oil oil is cold and heavy,or if the strainer (or oil delivered by the gear-type oil pump. Thispump cooler) is clogged. In such cases, the bypass valve takes suction through a screen froman oil pan is forced Open and the oil flows directlyto the or sump. From the pump, the oilis forced engine. Part of the oilfedto the engineis through the oil strainer and the oil cooler into returnedthroughthefilter,which removes the main oil gallery. This gallery extends the flakes of metal, carbonparticles, and other length of the eeirgirie and serves as apassage and impurities. reservoir from which the oil is fed to the main bearings. COOLING SYSTEM Constant oilpressure, throughout a wide range of engine speeds, is maintained by the Dieselenginesare equippedwith a pressure relief valve which allows the excess oil water-cooling system to carry away theexcess
163 169 FIREMAN
heat produced ine engine cylinders. The water directcurrentelectric motor. The motor is iscirculatedthr ughwater jacketsinthe designed to carry extremely heavy loads but, cylinder walls and passages that surround the becauseitdraws ahighcurrent(300-665 valves in the cylindhead. - amperes), it tends to overheat quickly. To avoid Eierifr-freshiwatr or sea water may be used overheating, NEVER allow the motor to run forooling. IV somengines the sea water is more than 30 seconds at a time. Then allow it to cool for 2 or 3 minutes before using it again. circ datedthroughtheengineandthen disci arged overboar Inother types,fresh To start a diesel, engine, you must turn it wateis circulated tlough the engine and then over rapidly to obtain sufficient heat to ignite the fuel. The starting motor is located near the through a heat exchanger. Sea water is circulated flywheel, and the drive gear on the starter is throughthis exchanger and cools thefresh water. An advantage of the fresh water system is arranged so that it can mesh with the teeth on that it keeps the water passages cleaner and thus the flywheel when the starting switch is closed. Iprovides better cooling and allows the engine to The drive mechanism must functionto(1) operate at higher temperatures. transmit the turning power to the engine when N the starting motor runs,(2) disconnect the starting motor from the engine immediately STARTING SYSTEMS after the engine has started, and (3) provide a gear reduction ratio between the starting motor There are three types of starting systems and the engine. (The gear ratio between the used in internal combustion engineselectric, driven pinion and the flywheel is usuallvabout hydraulic, and pneumatic. 15 to 1. This means that the starting motor shaft AsPFireman you will probably have more rotates 15 times as fast as the engine, or-at 1,500 c ntact with the electric starting system than rpm, to turn the engine at a speed of 100 rpm.) u will with the other two types. Most, if not The drive mechanism must disengage the all, lifeboats aboard ships use an electric starter pinion from the flywheel immediately after the to start the engine. engine starts. After the engine starts, its speed may increase rapidly to approximately 1,509- _Depending on shiptype,the emergency rpm. If the dive pinion remained meshed wit generator, whether it be diesel or gas turbine, is the flywheel and also locked with the shaft of started by either an electric starter or penumatic the starting motor ata normal engine speed starter. Main propulsion diesels and gas turbines (1,500 rpm), the shaft would be spun at a rapid are usually pneumatic starter systems (air start). rate-22,500 to 30,000 rpm. At such speeds, the Electric starting systems use direct current starting motor would be badly damaged. because electrical energy in this form can be storedinbatteries and drawn upon when Hydraulic Starting Systetns needed. The bat 's electrical energy can be restoredbychargingthebatterywithan engine-driven generator. There are several types of hydraulic starting systems in use. In most installations, the system The main components of the electric starting consistsofahydraulicstartingmotor,a system arethestoragebattery,the starting piston-type accumulator, a manually-operated motor, the generator, and the associated control hydraulicpump, anengine-drivenhydraulic and protective devices. The storage battery is pumprand a reservoir for the hydraulic fluid. described in detail inBasic Electricity,NavPers Hydraulicpressure isobtainedinthe 10086-B. accumulator by the manually-operated hand pump or from the engine-driven pump when the Electric Starting Motors engine is operating. When thestartingleveris operated, the The starting motor for diesel and gasoline controlvalveallowshydraulicoil(under engines operates on the same principle as a pressure) from the accumulator to pass through
`61 164 110 Chapter 12INTERNAL COMBUSTION ENGINES
the hydraulic starting motor, thereby cranking The CARBURETOR is a device used to send I the engine. When the starting lever is released, a fine spray of fuel into a moving stream of air spring action disengages the starting pinion and as it moves to the intake valves of the cylinders. closes the control valve, stopping the flow of The spray is swept along, vaporized, and mixed hydraulic oil from the'accumulator. The starter (as a gas) with the moving air. The carburetor is is protected from the high speeds of the engine designed to maintain the same mixture ratio by the action of an overrunning clutch. overawide rangeof enginespeeds. The The hydraulic starting system is used on MIXTURE RATIO is the number of pounds of some smaller diesel engines. This system can be air mixed with each pound of gasoline vapor. A applied to most engines now in service without RICH MIXTURE is one in which the percentage modification other than to the clutch and pinion ofgasolinevaporishigh,whilea LEAN assembly,whichmust bechangedwhen MIXTURE contains a low percentage of gasoline converting from aleft-handto a right-hand vapor. rotation.. The electrical system of the gasoline engine has the same units as the diesel engine, plus the Air Starting' Systems ignition system. This systemisdesigned to deliver a spark in the combustion chamber of Most modern large diesel engines are started eachcylinderataspecificpointinthat by admitting compressed air into the engine cylinder's cycle of operation. A typical ignition cylinders at a pressure capable of turning over system includes a storage battery, an ignition the engine. The process is continyed until the coil, breaker points, a condenser, a distributor, a pistons have built up sufficient compression heat spark plug in each cylinder, a switch, and the to cause combustion. The pressure used in air necessary wiring. starting systems ranges from 250 to 600 psi. There are two distinct circuits in the ignition Some largerengines and severalsmaller systemthe primary and the secondary. The engines are provided with starting motors driven primary circuit carries a low-voltage current; the by air. These motors are similar to those used to secondary is a high-voltage circuit. The battery, drive such equipment as large pneumatic drills the ignition switch, the ignition coil, and the and engine jacking motors. Air starting motors breaker points are connected in the primary are usually driven by air pressures ranging from circuit. The seconctiry circuit, also connected to 90 to 200 psi. the ignition coil, includes the distributor and the spark plugs. The STORAGE BATTERY is usually the 12- GASOLINE ENGINES and 24-volt type. One terminal is grounded to the engine frame, while the other is connected The main parts of the gasoline engine are to the ignition system. quite similar to those of the diesel engine. The The IGNITION COIL is in many respects twoenginesdifferprincipallyinthatthe similar to an electromagnet. It consists of an gasoline engine has a carburetor and an electrical ironcore surrounded bytheprimary and ignition system. secondary coils. The primary coil is made up of The induction system ofja gasoline engine a few turns of heavy wire, while the secondary draws gasoline from the f61 tank and air from coil has a great many trims of fine wire. In both the atmosphere, mixes them, and delivers the coils, the wire is insulated, and the coils are mixture to the cyl4ders. The induction system entirely separate from each other. consists of the fuel tan,the Juel pump, the TheBREAKER POINTSconstitute a carburetor, and the necessary fuel lines and air mechanical switch connected to the primary passages. Flexible copper tubing' carries the fuel circuit. They are opened by a cam which is from the tankto the carburetor, while the timed to break the circuit at the exact instant at intake manifold carries the fuel-ai mixture from which each cylinder is due to fire. A condensir there to the individual cylinders. The fuel-air is connected across the breaker points to prevent mixture is igted by an electric spark. arcing and to provide a better high-voltage spark.
165 171 FIREMAN a TheDISTRIBUTOR, connectedtothe The electricity that would otherwise arc across secondary or high-voltage circuit, serves as a the breaker points, as they are separating, now selector switch which channels electric current flows into the condenser. to the individual cylinders. Although the breaker The principal purpose of the condenser is to points are connected in the primary circuit, they protect the breaker points from being burned. are often located in the distributor case. The The condenser also aids in 'obtaining a hotter same driveshaft operates both the breaker spark. points and the distributor. The starting system of the gasoline engine is The SPARK PL11GS, which extend into the basically the same as that of the diesel engine. combustion chambers of thecylinders,are The generator keeps the battery charged and connected by heavy insulatedwires tothe provides the current to operate the lights and distributor. A spark plug consists essentially ofa other electrical equipment. The starter motor metal shell that screws into the spark plug hole draws current from the battery and rotates the in the cylinder, a center electrode embedded ina flywheel and crankshaft for starting. ? porcelaincylinder,anda sideelectrode connected to the shell. The side electrode is The electrical system usually requires about 90percentoftheroutinemaintenance adjusted so that the space between it and the performed on gasoline engines. You should keep center electrode is approximately 0.025 inch. the When the plug Res, an electric spark jumps connectionstightened and thebattery terminalscoveredwithalight across the gap between the electrodes. coating of pe tro 1 a t um. Unsatisfactoryoperationcan When the engineisrunning, the electric usually be traced to either dirty fuelor fouled current in the primary circuit flows from the spark plugs. If the fuel is strained before it is put battery through the switch, the primary winding in the tank, and if the tank is filled each time in the ignition coil, the breaker points, and then theengine issecured,mostofthefuel backtothebattery.The highvoltageis difficulties will be eliminated. A fouled plug can producedinthesecondarywinding inthe be removed and cleaned by wire brushingor ignition coil and flows through the distributor to sand blasting. theindividual spark plugs and back to the You will find detailed informatiori on spark ignition coil through the engine frame.Itis ignition systems in Engineman 3 & 2, NavPers interesting to note1fiat The high voltage, which 1054I-B. jumps the gap in the spark plugs, does not come from\the battery but is produced in the ignition coil. GAS TURBINE ENGINES The ignition coil and the condenser are the Until recently, the application of thegas only parts of the ignition system which requii4 turbine engine to marine use in the Navy has an explanation. The soft iron core and the been experimental. Experiments have proved primary winding function as air electromagnet. that the gas turbine engine can be used topower e currentflowing throughtheprimary short-range ships, landing craft, high-speed craft winding magnetizes the core. This same core and such as PT and air-sea rescue boats,emergency thesecondarywindingfunctionasa transformer. Variations in the primary current generators, and portable firefighting equipment. change the magnetism of the core which, in The MSB-5 class minesweepers were the first turn, produces high voltage in the secondary U.S. naval ships to use gas turbine engineson an operationalbasis.Gasturbineinstallations winding. aboard the MSB-5 class minesweepers supply With the engine running and the breaker power for the generators. pointsclosed,alow-voltagecurrentflows In the past few years several classes of ships through the primary circuit. When the breaker have been built, or are under construction, points open, this current is interrupted; this which are totally gas turbine. These shipsare of produces a high voltage in the secondary circuit. the size of the light cruiser and large DLG' class
166 -172' `o Chapter 12INTERNAL COMBUSTION ENGINES ships. Several other types of ships which are gas several advantages over reciprocating euines. turbine-powered areatvariousstagesof However, there are certain undesirable features development. of gas turbine engines. Not all of the desirable or As service experience has been gained, the undesirable features of gas turbine engines are number of gas turbines in use has increased. The discussed here, but some of the more important following discussion deals with a comparison of ones arepointedout. The advantages and gasturbines and reciprocatingengines,the disadvantages of the gas turbine engine cannot advantages and disadvantages of the gas turbine be listed in order of importance, because the engines and their principal parts, or components. requirements of the engine as a source of power differ in various applications. COMPARISON OF GAS TURBINES AND Compared withother types of internal RECIPROCATING ENGINES combustionengines,thegas turbine engine weighs less, takes up less space, and is normally The gas turbine is similar to reciprocating of simpler design with a smaller _number of enginesinthatairis compressed, afuel-air moving parts. The gas turbine engine develops mixture is burned, and the gases of combustion more power per unit of weight and unit of are expanded to produce useful power. Engines volume than other engines. ofthereciprocatingtypeuseone componentthecylinderforcompression, Gasturbineenginesstartquicklyand combustion, and expansion.Sinceallthree accelerate rapidly. Some models can develop full phases take place Within one component, the power from a cold start in less than one-tenth power impulse must occur intermittently or the time requiredfor adiesel engineina periodically, as the cycle is repeate.. This is not comparable application. The gas turbine adjusts true in gas turbine engines; instead, ompression, to varying loads more rapidly than other type combustion, and expansion take p ace in three engines. separate components. Air is comp essed in one component, combustiontakesdaceinan Thenumberofpersonnelrequiredto adjacent burner, and a turbinefor turbines) operate and maintain a gas turbine engine, and receives the energy generated by cobustion. As thetime requiredfor thetraining of such does the piston in a reciprocatinengine, the personr.e! are much less than for engines of turbine transmits the energy of thgases to a other types. Only one man is needed to start and shaft which drives a useful load. Th three basic operate some gas turbir4 engines. The simplicity components of the gas turbine e a ne are so of the operating controls and the automatic arranged and connected that the power output safety devices used reduce the time required for from the turbine is steady and co tinuous. In training operators. brief, the gas turbine engine can be defined as an internal combustion engine that produces power Compared to a diesel engine, the gas turbine by a continuous and self-sustaining process. An has far fewer components and produces much air mass is. compressed and then combined with less vibration atfullpower. The gas turbine atomized fuel. The resulting mixture is then enginehas a significant advantage over the ignited and burns. The combustion gas expands gasoline engine in the fuel used. The fuel used in through one or more turbines which change gas turbines presents much less fire hazard than some of the energy into useful power. the highly volatile fuel used in gasoline engines.
ADVANTAGES AND Even though the gas turbine engine has some DISADVANTAGES OF advantagesoverothertypesofinternal GAS TURBINE ENGINES combustionengines,it alsohassortie disadvantages, suchasa higher r to of fuel In additiod to the development of a uniform consumptioncilandlarger componen require flow of power output, gas turbine engines have for air inlet and exhaust.
167 tr. 173 FIREMAN
COMPONENTS OF compressor, combustion chamber (burners), and GAS TURBINE ENGINES turbine wheel(s). The COMPRESSOR isthatpart of the The gas turbine engine uses processes in its engine which draws in air and compresses it by operation which-aro similar to those employed centrifugalforce (that force which tends to in other types ofnternal combustion engines. move something outward fromacenter of The engine components and the terms used to rotation). The compressor consists of a rotating identify them are considerably different from impeller enclosed by a case. The BURNER is the parts and terms which are common to the that part of the engine in which combustion diesel and gasbline engines. Although gas turbine occurs. It consists of a cylindrical outer shell, engines vary in design and Navy installations perforated inner liner, fuel nozzle, and igniter include engines of other manufacturers, much of plug. A NOZZLE isa metal chamber which thediscusfioninthefollowingsectionis collects combustion gases from the burners and applicable to all gas turbine engines. directs them through fixed vanes or nozzles. The The components of a gas turbine engine may ROTOR is a rotating assembly, consistingof be grouped as (1) parts of the basic engine, (2) the compressor, an interconnecting shaft, and engine accessories, and (3) engine systems (fig. first-stage turbine wheel. 12-8). The section of the engine which changes energy into useful power is known as the power Parts of the output section. The main parts of this section Basic Engine are the power turbine wheel, exhaust ducts, reduction gear, and output shaft. The forward (compressor end) section of the The TURBINE WHEEL is a bladed disk engine, where a stream of hot expandable gases which turns when the exhaust gas stream acts is created as a result of continuous compression uponitsblades.Acircularmetalduct, and combustion, is called the gas producing containing a ring of fixed vanes that form section. This section consists principally of the nozzles, which directs the gas flow from the
COMBUSTION I CHAMBER (..
1
PROPULSION POWER STARTER COUPLING
COMPRESSOR SHAFT TURBINE
-0 EXHAUST TO ATMOSPHERE ATMOSPHERIC AIR INTAKE
147.135 Figure 12-8.Schematic diagram showing relationsh p of parts in single-shaft gas turbine engine.
1 168 1 7 4 Chapter 12INTERNAL COMBUSTION ENGINES first-stage turbine to the second-stage turbine is asa boat engineer.Refer to Basic Military calledtheINTERSTAGE NOZZLE Requirements, NavTra 10054-D, chapter 19, for ASSEMBLY. additional information.
Engine Accessories DIESEL - POWERED BOAT OPERATION The main engine components discussed to this point are not the only components required The actual operation of a small boat diesel to make a complete engine. Like other types of might be considered as consisting merely of internal combustion engines, the gas turbine starting it, regulating the speed, and stopping it. engine includes, various accessories. However, there are other factors which should The pa iswhichconstitutetheengine be considered. If you are goof to depend on the accessory gr up are driven by the engine rotor engine to give reliable service, you must give it a orbytheoutputshaft.The rotor-driven lot of attention. Your first experience in having accessories include the gear-type fuel pump, a casualty halfway between the ship and dock centrifugal fuel control governor, combination mayleavealastingimpressiononyou, pressure-scavengeoilpump. Acentrifugal. particularly if you happen to have the captain overspeed switch is driven by the output shaft. aboard. When you are assigned to a boat, your first Engine Systems responsibility is to inspect the engine and warm it up. You should check the fuel supply, the The principal systems of a gas turbine engine lubricating oil, and the cooling system. When are those which supply fuel for combustion, oil you are satisfied that everything is as it should for lubrication, and electricity or air for starting be, you are ready to start the engine. the engine and for the operation of instruments Starting a diesel engine ordinarily consists of and warning and safety devices. placing the throttlein the idle position, or The engine accessories are usually considered opening itpart way, and pressing the starter as components of whichever system they affect. button. The engine should start after the starter has turned it over a couple of times. It should be warmed up by running it at low speed until it is OPERATION OF up to operating temperature. SMALL BOAT ENGINES While the engine is warming up, you will have a chance to find out whether it is in good When a ship is at anchor, the officers and running condition. Watch the instrument panel crew travel to and from the shore in small boats. to help you determine the condition of the As a Fireman, you may be assigned as an engine. (See fig. 12-9.) For example, if the oil engineer on one of these small craft. A coxswain gage fails to register any pressure, you should will be in charge of the boat. In some boats stoptheengineimmediately.Thewater there may also be two seamen actpg as bow and temperature gage is used as an indication of the stern hooks. temperature of the engine parts. The engine You will be responsible for operating the exhaustisusually cooled by sea water; the( boat's engine. You will receive your orders from exhaustdischargeshouldbeinspected the coxswain over the boat's bell system. You immediately after starting to determine whether should know the. bell signals; two sounds for the water pump has suction. If the pump does, neutral, one for slow ahead, three for reverse, not have suction, stop the engine and check the and four calls for full speedin the direction in cooling system for such troubles as a clogged which you are going. The coxswain will expect strainer and closed sea valves. You should check you to comply with the bells instantly. You will the idling speed by bringing the throttle back to be required to follow certain safety precautions the idling position. The engine should respond
-169 1 7 5 FIREMAN
the proper grade approved for that particular engine is used. The engine can be stopped by merely closing thethrottle. You 'shouldleavetheengine compartment clean and orderly. A report calling attention to any abnormal operating condition that you may have noticed will bea help to the maintenance and servicing crew. Another importantpartof your jobis TROUBLESHOpTING. Diesel engine failure'can uscially be attributed either to the fuel systemor to improper cooling or lubrication. If the fuel is not reaching the engine cylinders, you can often trace the trouble to an empty fuel tank oran accumulationof waterinthestrainers. A plugged vent in the fuel tank filler cap willcause a vacuum to form in the top of the tank, and the engine will stop for lack of fuel. Overheating generallyresults from a lack of either oilor cooling water. 0 GASOLINE ENGINE 139.48 OPERATION Figure12-9.The instrument panel of a small ( diesel-powered boat. The operationof asmall boat gasoline engine is similar Cothat of a diesel engine. Since gasoline from a leak or an 'open container will normal'y to changes in the throttle setting, and vaporize quickly and may form an explosive it should run smoothly after being broughtup to mixture, additional precautions against fire must operating temperature. be taken. Adequate ventilation must be provided toridtheenginecompartmentofany Yotr should know wherethefuel- and combushblevapors which may accumulate. No lube-oilkrainer drains are located so thatyou smoking is permitted in small boats atany time, can get- rid of any water that may accumulate in this is especially important in boats equipped these sy4tems. If lube oil must be added, see that with gasoline engines.
cPf
17C
'170 CHAPTER 13
ENGINEERING WATCHES
Throughout the chapters of this training conditions with other ships, when enteringor manual you have become acquainted withthe leaving port, or when refuelingor replenishing organizationand ratingsof the engineering from another ship. Because the JVcircuit is used department. You may be assigned toone of toprovide communications between allthe many different types of ships. On these ships engineeringspaces, you must ;-now proper you will find that the engineering spacesvary in telephone procedures; when size and appearance. If you talk, speak you are assigned to a slowlyandin a verydistinctmanner steam-driven ship, you may find the boilers,the pronouncing Qte syllables of each wordvery main engines, and their associated equipmentin clearly. When you receivea message, or are given one space; or you may find the boilers and their a message to transmit, be sure to repeat it word equipment in one space, and the main engines for word, exactlyas it was given to you; do not an d theirequipment inanotherspace. engage in any idle chatter. Regardless of the number of boilers andmain As the messenger on the watchyou will also engines, many of the watchesare basically the perform such other dutiesas the petty officer of same. Therefore, the information in this chapter the warcl may designate. This includeschecking is generalinnatureand doesnot apply alloperating machinerytoseethatitis specifically to any one ship. operating, properly, recordingtemperature and This cha ter contains information relatedto pressure readings in the appropriate logs, and some of thektches and the duties thatyou will calling the watch relief. be required t perform such as messenger of the The' dy,\erating log is an hourly record.of watch,soup ingand securitywatch,and operating pressures and temperatures ofalmost cold-iron, watch.' As youprogress and become alloperatingmachinery..Thelogreadings acquainted with the fireroomor engioneroom include lubeoilpressures and temperatures, you will be required to stand otherfwatches boilerpressuresandtemperatures,pump under the supervision and instruction ofa petty suctions and discharge officer.These watches include: pressures, and other items (1)forthe ofimportancetotheoperationofthe fireroomburnerman,blcvwerman,and engineering plant. You will be requiredto write checkman; and (2) for the engineroomlower and print legibly, to correctly spell levelwatch,upper common levelwatch,evaporator Navy terms and to maintainyour logs neatly and watch, shaft alley watch, and throttle watch. accurately. You should become acquaintedwith proper operating pressures and temperaturesso that you will know whena piece of machinery MESSENGER OF THE WATCH or equipment is not operating properly. The messenger of the watch-- performs a number of important (1,4t;,,awilit.h involve a SOUNDING AND SECURITY WATCH great' deal of responsibility. Themessenger is usually assigned as telephonetalker on the As a Fireman you will be requiredto stand engineering JV circuit during close maneuvering sounding and security watches. Whileon this
171 e44 4177 FIREMAN
watch, your primary mission is to look for fire 'weighted at the end to facilitate lowering into and flooding hazards. On most ships, this watch the sounding tUbe. is from the end of the working day until 0800 the next morning and is also in effect during holidayroutine.Thewatchisparticularly HOW TO TAKe needed at these times because there are fewer A SOUNDING personnel working aboard 'the ship and certain spaces that require frequent observation are not Wher is relatively hard tosee on a brass or under thenormal observationof personnel bronzesoundingrod.Before'yoUtakea workinginornear them. On someships sounding, dry the rod or tape thoroughly and (particularlythelarger ones), sounding and coatitwith whitechalk. When the chalk security watches are stood around the clock. becomes wet, it turns to a distinctly visible light When you standthis watch, in addition to brown color. For example, if there is 6 inches of looking for fire and flooding hazards, be sure water in a tank when you take a sounding, the that no fresh water spigots are leaking or left light brown,color of the chalk will be distinctly runninginheads,washrooms, galleys,and visibleuptothe6-inch mark; whilethe pantries. Another of your responsibilities while remainder of the sounding rod willstill be on watch is to maintain the-proper condition of covered with the white chalk. The chalk method material readiness by checking all watertight air is used only where water may be present. ports, doors, hatches, scuttles, and all other When you have coated the sounding rod damage controh-fittings. Report any irregular with chalk, lower it down the tube until it condition (change in soundings, violations of touches the bottom; immediately draw it back. material condition, fire hazards, etc.) to your Do not drop the rod or tape to the bottom, but watch supervisor. lower it slowly so that it his bottom without injuring the rod or tape. If the ship is rolling, tj,k SOUNDINGS to lower and hoist the rod or tape while the ship is on an even keel. After you have taken the A soundingtube isusuallymadeof sounding, enter the reading in the sounding log. I I /2-inch pipe. The lower end is fitted at a low point in the compartment, tank, or void which the tube serves. The upper end terminates in a COLD-IRON WATCH flush deck plate which is usually located on the main or second deck; it is closed with a threaded When a ship moves alauside aepair shipor plug or cap. , atender, or intoa navalshipyard,, and is Tubes are made as straight as possible, but receiving power from these activities,a security strrieare, necessarily curved. Some sounding and'fire watch is usually set by each department. tubes, partichlarly thOse serving spaces under the This watch is commonly called the COLD-IRON enginerooms and firerooms, cannOt be extended WATCH. to the upper decks because of the construction of theship. These tubes terminate inrisers Eachcold-ironwatchmakesfrequent 0, which extend approximately 3 feet above the inspections of the area, assigned to him and looks compartmentserved;theyhavegatevalve forfire hazards or other unusual, conditions closures. throughoutthearea.He seesthatno Soundingare taken with a sound rod or unauthorized persons are in his watch area, that sounding tape, whichever is provided for that all spaces are cleaned, and that no tools,rags, gear, and the like are left, adrift. He keeps bilges purpose aboard ship. Normally, the sounding rr rod is approximately 6 feet long and is made of reasonably free of water. 12 -inch lengths of 1/2-inch brass or bronze rods. The watch makes hourly reports to the It is lowered with a chain or line. The sounding officer of the deck as to alt, existing conditions. tape is a steel tape, coiled on a reel suitable for Any unusual conditionsthat do existare holding while the tape is lowered. The tape is reported -to the officer of the deck immediately
c 172 178 Chapter I3ENGINEERINGWATCHES sothatthedepartment responsible can be M enginespeedandsteamconditions notifiedtotakethenecessarycorrective change, the bumerman must rapidly eut burners measures. in or out, as required, to hold the steam pressure' In the event that welding or burning is going steady. -During maneuve'rIng il, close contact on in his area, the -gold-iron watch sees that a with other ships, and when the ship is entering fire watch is stationed. (The fire watch stands by orleaving ...port,thebumerman mustbe with a CO2 extinguisher.) If none has been constantlyalertforlarge,rapid changes in stationed, the cold-iron watch has the work engine speed. '; discontinueduntilthefirewatch has been stationed. The cold-iron watch carries out all orders and special orders pertaining to the duties BLOWERMAN of that watch. If the ship is in drydock,.the cold-iron watch The blowerman is responsible for operating checks all sea valves after workingw hours to see the\ forced draft blowers that supply combustion that the valves are secure or are blanked off. He air to the boiler. Although the air pressure in the mustseethatnooilis pumped' intothe double casings isaffected by the number of drydocks at any time. He Wiill not allow any registers in- use and the extent to which each weights, such as fuel oil, feedwater,' or potable register is open, it is chiefly determined by the Water, to be shifted without perniission of the ,manner in whiCh the forced draft blowers are operated. The opening, setting, or adjustingof engineeofficer. , LL the air registers is the BURNERMAN'S job. The The cold-iron watch must be controlofforceddraftbloWers is the -a II regulations,instructions,anoNi safety BLOWaRMAN'S job. Itis important that the precautionsandmustseet 1W (tites'earc bumerman and the blowerman cooperate with observed. He giveshisrelief aWinformation. -each other because both are concerned with the regarding existing conditions, orders, and special combustion of the fuel oil. orders. If the relieving watch is not satisfied with 4- the conditions, he will not relieve him, but will report for instructions to the petty officer with the day's duty. CHECiMAN The checkinan is responsible for operating the feed stop valve and the feed check valve. The BURNAIMAN checkman has ONLY ONE JOBto maintain the proper water level in the boiler: This job requires The bumerman 'maintainsproper steam full attention at all times. When a boiler is being pressure by cutting burneit in or out, or by operated srrianually,the checkman must NEVER regulating the fuel, oil ppessure at the burners. be giVen'any tither duties. The steam pressure must be held at the working Someshipsareequippedwithfully pressure,amqp- assteadyaspossible.The automatic feedwat on s, so a checkman is bumerman 'must keep a close check for dirty not 'normally needed. Hovyev,T, if the automatic atomizers, by observing their operation and the system fails or is switched to mantkal control, condition of the fire. He changes the atomizers therra checkmah must be imm diately stationed when authorized by tyre petty officer in charge on the checks. of the watch. The burner7man depends on a steam pressure gageand ,asuperheated steam anaperature THROTTLE WATCH thermometer for information °onconditions within the boiler. In most cases anengine'gder The tasks. of a throttkman, atthe main telegraph(annunciator) locatednearthe engines are very important: Orderi from the burner front' so that 'the fireroom watch will bridlerelative to movement' of the propellers, know what main engine changes,ale being Made. .becomplied with immediately. To. make''must
I73 1- 7 9 4 1 ti
FIREMAN
correct adjustments for the required speed, you the pumps -and equipment, you must learn to must keep a (-lose watch on the rpm indicator on make various routine checks on the operating thethrottl/board and open orclosethe machinery. Some of the checks for the main throttle, arequired: to attain or maintain the feed punip, the lube oil pump, and the main necessary, rpm.Inadditionto handling the condensate pump.are discussed in the sections throttle itself, you may also have to operate a thatfollow. alnder the watchful eye of -the variety of associated valves, accurately log all pumpman, you willlearn how to make the speed changesintheEngineer'sBell Book, following checks and to perfbrni the following visually 'check all gages (pressure, temperature, duties. vacuum, etc.) installed on the throttle board, and keep the petty offices' in charge informed of MAIN FEED PUMP any abnormal gage readings. You should become thoroughlyfamiliar In addition to complying with the posted with all the gages, instruments, and indicators on instructions and safetyprecautionsforthe the throttle board so. thatypti wilt know what a machinery and equipment at this station, the normal readingis.ThereAare steam pressure pumpman performs the following auties: gage< steamternperatur thermometers, a revolutions-per-minute(rpm)indicator,an II 'Maintains mainfeed pump discharge engine order telegraph, feedwater pressure gages, pressure at a predetermined 'value by adjusting cooling water pressurepies, gages indicating the the constant presire governor, vacuum obtainedinthemain engine low - 2.Keeps ihfain feed pump bearing s at the pressureturbine,andothers.Whenever an proper temperature by regulatinrtothe flow .of opportunity presents itself, study thelAhrottle water through tha.feed pump lube oil cooler. board and ask questions. Do not hesitate to ask 3.Checks to ensure proper lube oil pressure the operator whether those are normal readings, to the bearings. and whether they are the approximate readings 4.Keepsshaftpacking glandsadjusteli you should alwaykqee there during steaming properly. A smallleakageisnecessd.0 ,f9r conditions.When --ouhave learnedthe lubrication to prevent burning out the *kilt, difference between a normal reading and an but an excessive amount of leakage wastes boiler abnormal reading, you max possibly help- to f eedwater. preventamajor casualty 'by observing an 5.Checks and maintains proper 1 e oil - abnormal reading and reporting it to the petty level in the main feed pump sump tank. officer in charge of the watch. 6.KeeRs valve packing glands tightened to P 0 V4, ' prevent leak4. 7.Keeps his watch station clean; removes LOWER _VEV*Et. WATCHES fire hazards by wiping up oil and pickingup rags c. and other stray gear. When you are assied to the lower level to Is alert for unusual sounds, vibrations, assist the lower levelatch (pumpman) and to temperatures, and pressures. learn his duties and reonsibilities, you will find 9.Keeps thestandby pump readyfor considerable nber of pumps and other instant use. auxiliary machinery. Some of the pumps anV equipment you will find are the main lube oil LOBE OIL pump 'pumps and lube oil coolers, main condensate pumps and main conderiser and, when installed 1.Maintainstheproper lukkeoil' pump in the engineroom, main feed*, pumps, main feed discharge pressure by adjusting the constant booster pumps, and'firepumps.. In some pressure governor. installhtions you 91 als9.--1incl air compressors 2.Keeps the stand y -pump bn automatic on the lower level.. standby, ready for istant use. Inaddition,tolearningtheproper 3.Shirts and cles main rube oil strainers procedures for starting, operating, and stopping once each watch or mo aften if required. Chapter 13 ENGINEERING WATCHES
4. "ChIcks the lube oil system for leaks valveadjustmentstocorrectconditions maintains the proper off level in the main en indicated by slight variations from the normal sump tank. readings, and report unusual con bons to the 5, Operates the lube oil purifier as ordered. petty officer In charge; maintain a normal water 6.Checks the oil pres'sure,to the lube oil levelinthe deaerating tank, ifitisin the service pump bevings and maintains the oil at engineroom, by adjusting the excess and makeup theproper ,,tepera,turebyregulating' 'the feed valves; light off and secure turbogenerators; amount of water through the pump lube oil and other upper level machinery, as ordered; and cooler. , maintain an adequate gland seal pressure on the 7.Regulatesthecoolingwaterflow turbogenenitor. through the lube oil cooler go maintain the correct oil outlet temperature. SHAFT ALLEY WATCH MAIN CONDEN$ATJ PUMP Another main engine duty to which you I.Keeps the condensate in the condenser may be assigned is that of keeping watch on the hot well at the proper level. bearings of the propeller shafts leading froin the 2./ Frequently checks the exhaust trunk and reduction gears (or motors of a turboelectric m a in condenseroverboardforabnorinal driven ship) to the ship's propellers. The shaft temperatures. alley watch stander: 3.Checksthemaincondensate pump bearings for proper oil pressure and temperature. 1.Checksallspring bearings for proper 4.Keeps fhe main condenser vented. lubrication, including correct oil level, condition 5.Starts or secures an additidnal pump, as of the oil, proper operation of self-oiling devices required, to keep the ;condensate level at the (ring or cjiain), and bearing temperature. correct height. 2.Checks and adjustsstern tube gland for 6. 'Constantlychecksfqr. unusual correct amount of leak-off. conditions such as vibrations, sounds, and high 3. is responsible for having the shaft, alley or low temperature or pressures. bilge -pumped. 4.Is to be especially alert during high speed All watch standers should be constantly alert toobserveanyabnormal,riseinbearings 'for signs of leakageln all parts of the steam and temperature. water systems. Some of the more common 5.Reports hourly, by phone, to the control causes of feedwater waste are: (1) leaks in pipe engineroom and at any time that abnormal fittings, flanges, valve and pump packing glands, conditions develop: pump hodtings and relief valves'? (2) use of 6. In ships, which have the main thrust excessive gland sealinestak and (3) failure to bearing in the shaft responsible for shift drains from-glie.bilie to the appropriate operation of the main thruiT bearing lube oil drain system.Using an excessive amotint of system. boiler feedwater is an indication of a poorly 7.Performs any other additional duties operated plant and reflects on the lility bf the which may be assigned. watch stander.
EVAPORATOR WATCH UPPER -LEVEL 'WATCH A ship requires a large amount of pure fresh VVVhen,yoli are"assignedto the dutrerbf the ater daily, yet a ship can only store sufficient upper level watch in the engineroom, you will water to last a few dayi; therefore proper and record , periodictemperatureandpressure careful watches must be maintainedon the readings fr he various gages otw, or connected evaporators whenever theyare in operation. to, the upp evel machinery; make required Proper watch standing requires the operator to 475 181 FIREMAN constantlycheckpressures,temperatures, compartment number, name, rating, and rate vacuim, and salt content of the distilled water. (actual and allowance). The stiff) cannot operate if the distilled water 3.Watch assignments for each person under that is to be used for feedwater contains more various conditions of battle readiness. salt than the maximum allowable limits. 4.Station each person will have arfd -what he will provide for emergency situations Such as Fire,RescueandAssistance,andGeneral OTHER WATCHES Emergency. OR ASSIGNMENTS 5.Visit and search party, landing force, spettflsea detail, and other special duties and EachdivisionOfficerpreparesa Watch, stations which each person is assigned. Quarter, and Station Bill for his division. You will generally find the following information on . The Watch, Quarter, and Station Bill to Is this bill: you where' you fit into the ship's organizatio al picture. Check it frequently, for it is your duty I.Organizationofthedivision(i.e., to know where you belong udder all conditions. sections and watches). There is NO EXCUSE FOR NOT KNOWING. Thebillsmay bedifferentlydesignedfor 2.Listingof, eachpersonastobillet different ships,. but the stations and duties are number,lockernumber,bunknumber, always approximately the same.
4
is
182
176 p
APPENDIX I
GLOSSARY
, When you enter a new occupation, you must AFTERCOOLER: Ai terminalheat- transfer learn the vocabulary of the tradeso that you unit after the last stage. understand your fellow workmen andcan mq,ke yourself understood by them.Shipboard life requires that Navy personnel learn AIR EJECTOR: A type of jetpump, used to a relatively remove air and other gases from the condensers. new vocabularyeven new termsfor many commonplace items. The reasons for this need aremany, but most of them boil down to AIR CHAMBER: A chamber,usually convenienceandsafety.Undercertain bulb-shaped, on the suction and dischargesides eircbmstances, a word or a few wordsmay mean of a pump. Air in the chamberacts as a cushion an exact thing or may mean a certain sequence and prevents sudden shocks to thepump. of actions which makes itunnecessary to give a lot of explanatory details. edit REGISTER: A device inthe casing of a A great deal of the work ofa Fireman is boiler which ,regulates the amount of air for -.4-such that an incorrectly interpreted inOruetion combustion and providesa circular motion to could cause confusion, breakage of machinery, the air. . or even loss of life. Avoid this confusio4nd its attendant danger by learning the meaning -of AISE:Association. of.lron and Steel Engineers. terms common to the Engineering Department. This glossary is not all-inclusive, but it does ALLOY: A mixture of two ormore metals. contain many terms that every Fireman should know. The terms given in this glossarymay have ALTERNATING. CURRENT fa-c): Current more than one definition; ortly those definitions that isconstantlychanginginvalueand as related to engineering are given. direction at regular recurring intervals.
ttBT (automatic pus transfer):An automatic AMBIENT TEMPE mperature electrical device that suppliespower to vital of the surrounding area. equipment. This devicewill, shift from the
normal power supply toan alternate power AMMETER: , An instrument for measuring the supplyany time,'thenormalsupply is rite of flow of electrical current inamperes. interrupted. EALING: Thesofteningof,. metal by ACETYLENE: A gasthatischemically heatingand slow cooling. produced from calcium carbide and water,used r for welding and cutting. A*UNCIATOR: See ENGINE ORDER TELEGRAPH. ADAPTER: A couplingor similar device that permits fittingsfittingswith different-sized openings , ARGON:An inert gas, slightly heavier,,,than (apertures) air, be joined together. used in inert-gas shielded metalarc welding.
177
V 183 FIREMAN
ARMORED CABLE:An electric cable that is BOILER OPERATING STATION: A location protected on the outside by a metal covering. from which boilers are operated.
ASTM:`American Society for Testing Metals. BOILER RECORD SHEET: A NavShips form maintained for each boiler, which serves as a AUTOMATIC COMBUSTION CONTROL monthly summary of operation. SYSTEM (ACC):A system that automatically controls the fuel and air mixture in a boiler. BOILER REFRACTORIES:Materials used in AUXILIARY MACHINERY: the boiler furnace to protect the boiler from Any system or heat of combustion. unitof machinerythatsupportsthe main propulsion units or helps support the ship and the crew. Example: Pump, evaporator, steering BOILER ROOM: A compartment containing engine,air-conditioning,andrefrigerator boilers but not containing a station for operating equipment, !aunt*/ and galley equipment, deck orfiringtheboilers.Refers specificallyto winch, etc. bulkhead enclosed bo4r installations. IAN'Sr" BACK PRESSURE:The pressure'. exerted on BOILER TUBE CLEANER: A cylindrical the exhaust side of a pump or engine. brush that is used to clean the insides of boiler tubes. BDC (bottom dead center):The position of a reciprocating piston at its lowest point of travel. BOILER WATER: Thewateractually contained in the boiler. BALLASTING:The process of filling empty tanks with salt water to protect the ship from BRAZING: A method of joihing two metals at underwater damage and to increase its stability. high temperature with a molten alloy. See DEBALLASTING. BRINE: A highly concentrated solution of salt BLUEPRINT: Reproduced copy of drawing in water, normally associated with the overboard (usuallyhavingwhite lineson a blue discharge of distilling plants. background). BRITTLENESS:That property of a material BOILER: A strongmetaltank orvessel which causes it to break or snap suddenly with composed of tubes, drums,'and headers,in little or no' prior sign of deformation. whichwater is heatedbythegasesof combustion to form steam. BULL GEAR:The largest gear in reduction gear trainthe main gear, as in a geed turbine BOILER CENTRAL CONTROL STATION: A drive. centrally,locatedstationfordirectingthe control 6f all boilers in the fireroom. BURNERMAN:Man in fireroom who tends the burners in The boilers. BOILER DESIGNPRESSURE:Pressyre specified by the manufacturer, usually about BUSHING: A rivewable liningforahole 103% of normal steam drum operating pressure; through which a moving part passes. BYPASS:To divert the flow of gas or liquid.' BOILER INTERNAL FITTINGS: Allparts Also, the line that diverts the flow. inside the boiler which colntrol the flow of steam and water.. CALIBRATION: Thecomparisonof any measuring instrument with a set standard. BOILER OPERATING PRESSURE: 'The pressure required to he maintained in a boiler CANTILEVER: A projecting arm or beam while in service. supported only at one end. . 0 178 /-\ - 184 Appendix I GLOSSARY
CAPILLARY TUBE: A slender, thin-walled, CONSTANT PRESSURE GOVERNOR: A small-boredtubeused withremote-reading. device that maintains a constantpump discharge, indicators. pressure under varying'loads.
CARBON DIOXIDE: A colorless, odorlessgas CONTROLLER: A device Lsed to stop, usedasa start, fire.( extinguishing agent and for and protect motors from overloads, whilethe inflating liferafts A-0 lifejackets. motors are running. CARBON PACKING: Pressedsegments of COOLER: Any device thatremoves heat. Some graphite used to prevent steam leakage around devices such as oil coolersremove heat to waste shafts. inoverboard seawaterdischarge, and other devices such as an ejector coolerconserve heat CASUALTY POWER SYSTEM: Portable by heating condensate for boiler feedwater. cables that are rigged to transmitpower to vital equipment in an emergency. CORROSION: The process or being ;aten away gradually by chemical action, sucfir CHECK VALVE: A valve that permitsthe flow as of a liquid in one direction only. rusting.
CHILS? SHOCKING: A method thatuses steam COUNTERSINK: A cone-shaped tool usedto and cold water to rem9ve scale from'thetubes enlarge and bevel one end ofa drilled hole. of a distilling plant. CREEP-RESISTANT ALLOY:' A metal which CHLORINE: A heavy,,greenish-yellowgas used resists the slow plastic deformationthat occurs in water purification,sewage disposal, and in the at high temperatures when the materialtis under preparation of bleaching solutions. Poisonou's in constant stress. concentrated form. CROSS-CONNECTED 'PLANT: A method of CIRCUIT BREAKER: An electrical,device that operating two or more plantsas one unit from a provides circuit overload protection. .4 common steam supply. CLUTCH: A form of coupling designed _tp CURTIS STAGE: connect A velocity-compounded or disconnectadriving or then impulse turbine stage that hasone pressure drop member. in the nozzles and two velocity dropsin the blading. COLD IRON CONDITION: An idle plantas in a destroyer when all port services are received DEAERATING FEED TANK (DA tank):A from an external ,source suchas shore or tender. unit in the steam -water cycle that (1) frees the condensate of diisolvedoxygen, (2) heats the CONDENSATE: Water produced in the cooling feedw.ater,. and (3)actsasareservoir for system of the steam cycle from steam that has feedwater. returned from the turbine or from steam thathas returned from various heat exchanges. The water DEBALLASTING: The process by which saltis .is used over again to generate steam in the boiler emptied from tanks to protect the shipfrom for an endless repetitive cycle. underwater damage and to increase its stability. P CONDENSER: A heal transfer device in which DEGREE OF SUPERHEAT:The amount by steam or vapor is condensed to water. which the temperature of steamexceeds the saturation temperature. CONDUCTION: A method of heat transfer from one body to another when the two bodies DIRECT CURRENT (d-c):Current that moves are in physicalgontact. in one direction only.
179 185 FIREMAN
DIRECT DRIVE:One in which the drive ELECTROMOTIVE FORCE (EMF):A force mechanism is coupled directly to the driven that causff electrons to move through a closed member. circuit; expressed in volts.
DISTILLATE: Water produced indistilling ELEMENT: A substance which consists of plants. chemically united atoms of one kind. ENERGY: The capacity for doing work. DI STILLINGPLANTS: Unitscommonly calledevaporators(evaps) usedtoconvert ENGINEER'S BELL BOOK: A legal record, seawater into fresh water. maintained by the throttle watch, of all ordered mair),engine speed changes. DRAWING: Illustratedplansthatshow fabrication and assembly details. E INE ORDER TELEGRAPH: A device on th ship'sbridgetogiveorderstothe DRUM, STEAM:The large tanlrat the top of en ineroom. Also called ANNUNCIATOR. the boiler in which the steam colltcts. EPM (equivalents per million):The number of DRUM, WATER: A tank at the bottom of a equivalent parts of a substanZe per million parts bOiler; also called MUD DRUM. of another substance. The word "equivalent" refers to the equivalent weight of a substance. DRY PIPE:A perforated pipe at the highest EVAPORATOR: A distilling device to produce point in a steam drum to collect steam. fresh water from seawater. DUCTILITY: Property possessed by metals EXPANSION JOINT: A junction which allows that allows them to be drawn or stretched. for expansion and contraction.
ECONOMIZER: A heat transfer device on a FATIGUE: The tendency of a material to boiler that uses' the gases of combustion to break under repeated strain. preheat the feedwater. FEED HEATER: A heat transfer device that EDUCTOR: A jet-type pump (no moving heats the feedwater before it goes to the boiler. parts) used to empty flooded spaces. FEEDWATER: Water ofe hight possible level of purity made in vaporats for use in EFFICIENCY: The ratio of the output to the boilers. input. FERROUS METAL:Metal with a high iron ELASTICITY:The ability of a material to content. return to its original size and shape. FIREBOX: The section of a ship's boiler where ELECTRODE:A metallic rod (welding rod), fuel oil combustion takes place. used in electric welding, that melts when current FIRE MAIN:. The saltwater line that provides is passed through it. firefighting water and flushing water throughout the ship. ELECTROJIIYDRAULIC STEERING: A system 180.a AppendixIGLOSSARY FLASH POINT OF OIL;The temperature at GAS FREE: A term used to describe which oil vapor will flash into fire although a space the that has been tested-and found safefor hot work main body of the oil will not ignite. (welding and cuttjng). FLEXIBLE I-BEAM: An I-shaped steel beam GEARED-TURBINE DRIVE: A turbinethat on which the forward end of a turbine is drives a pump, generator,or other machinery mounted; it allows for longitudinalexpansion through reduction gears. and contraction. GROUNDED PLUG: Athree-pronged FLOOR cLATES: The removabledeck plating electrical plug used of a rueroom or engineroom aboard ship. to ground portable tools to the ship's structure.' It isa safety device which always must be checked priorto your using FLUX: A chemical agent that retardsoxidation portable tools. of the surface, removes oxides alreadypresent, and aids fusion. HAGEVAP SOLUTION: A chemical compound used in distilling plants. toprevent FORCE:Anything that tends to produceor the formation of scale. modify motion. HALIDE LEAK DETECTOR:A device thatis FORCED. DRAFT: Air underpressure supplied used to locate leaks in refrigeration to the burners in a ship's boiler. systems. HANDHOLE: An opening largeenough for the FORCED DRAFT BLOWERS:Turbine- driven hand and arm to enter the fans which supply air to the boiler boiler for making furnace. slight repairs and for inspectionpurposes. FORCED FEED LUBRICATION: A HANDY BILLY: A small portablewater pump. lubrication system that usesa pump to maintain a constant pressure. HARDENING: The heating andrapid cooling (quenching) of metal to inducehardness. FORGING: The forming of metalby heating and hammering. HARDNESS: The ability (ofa material to resist penetration. FRESH WATER SYSTEM: A pipingsystem which supplies fresh water throughout the Ship. " HEADER: A chamber,or tank, located within a boiler, to which tubes are connectedso that FUEL OIL MICROMETER VALVE:A valve water or steam may pass freely from installed at the burner manifold, one tube to that controls the other(s). 'Similar to,but Mailer than-, a the fuel oil pressure to the burners. water drum. FUEL OIL 'SERVICE TANKS:Tanks which HEAT EXCHANGER: Any provide suction to the fuel oil service device that allows pumps to the transfer of he-at fromone fluid (liquid, or discharge o4-tQ theers.,,,,, - gas) to another. , II. , FUSE: \ A protective device that willopen. a HYDROGEN: A r circuitifthe higi explosive,light, current. .flowexceedsa invisible, nonpoisonousas used in underwater predetermined valtie. -t-z..'' welding and cutting operations. - . 4, GAGE GLASS:A device that indicates the HYDROMETER* An liquid level in a tank. instrumentusedto determine thevspecific gravity ofliquids. 1.81 1.8.7 FIREMAN ,HYDROSTATIC TEST:A pressure test that bypass damaged sections of a pipe, 'a hose, or a uses water to detect leaks in a boiler or in other wire. (See BYPASS.) closed systems. 13- JURY RIG:Any temporary or Makeshift device. IGNITION, COMPRESSION: When the heat generatedbycompressioninaninternal combustion engine ignites the fuel (as in a diesel LABYRINTH PACKING: Rows of metallic engine). strips or fins that prevent steam lebitage along the shaft of a turbine. IGNITION SPARK:When the mixture of air and fuelin an internal combustion engine is LAGGING: A protective and confining cover ignited by an electric spark (as in a gasoline placed Over insulating material. engine). LIGHT OFF:Start. Literally, to startiltfffe in, IMPELLER: An encased,rotating element as in "light off a boiler." provided with vanes which draw in fluid at the center and expel it at a high velocity at the outer LOG- BOOK: Any chronological record of edge. events, such as engineering watch log. IMPULSE TURBINE: A turbine in which the LOG, ENGINEERING: A legalrecordof major part of the driving force is received from ,.importanteventsanddataconcerningthe the impulse of incoming steam. machinery of a ship. INDIRECTDRIVE: Adrivemechanism LOG ROOM: Engineer's office aboard ship. coupled to the driven member ,by gears or bets. LUBE OIL PURIFIER:A unit that removes INERT:Inactive. water and sediinent from lubricating oil by centrifutal force. INJECTOR: A device which uses a jet of steam to force water into the boiler. Injectors are also used in the diesel engine to force fuel into the MACHINABILITY: The ease with which a cylinders. metalmaybeturned,planed,milled,or otherwise shaped. INSULATION: A material used to retard heat transfer. MAIN CONDENSER: A heat ex ner which converts exhaust steam to feedwat r. I NT E RCOO LE R: Anintermediateheat transfer unit between two successive stages, as in MAIN DRAIN SYSTEM:,Syst nr usedfor an air compressor. pumpingbilges;consistsofpumpsand associated piping. JACKBOX: Receptacle, usually secured to a \;\ bulkhead,inwhichtelephonejacksare MAIN INJECTION (sCoOpinjection): An mounted. opening in the skiin of a ship through which cooling water,'ehvered to the main condenser -JOB ORDER:An order issueby ,a re ..jr and mgiirli er by the forward motion activity toits own subdivision to perform a ofsthe sp. repair job in,response to work request. \ MAKEUP FEED:" Water of required purity for JUMPER: Any connecting Pipe, hose, or wire, use in ship's boilers. This water is needed to normally used in emergencies aboard ship to replace that lost in the steam cycle. ' ,ar. 182 Appendix IGLOSSARY MALLEABILITY: That property ofa material OIL KING: which enables it to be stamped, A petty officer who recoiv.es, hammered, or transfers,discharges, and lustsfuel. oil And rolled into thin sheets. maintains fuel oil records. MANIFOLD: A fitting withnumerous OIL POLLUTION ACTS:The Oil" Pollution branches which conveys fluids betweena large Act of 1924 (as amended) aid the pipe and several smaller pipes. Oil Pollution Act of 1 961 prohibit the overboarddischarge of oil or water, which contains oil,in Port, in any MECHANICAL ADVANTAGE (MA): The sea area within 50 stiles of land, and inspecial advantage (leverage) gained by theuse of devices prohibited zones. such as a wheel to opena large valve, chain falls and block and-tackle to liftheavy weights, and ORIFICE: A smail opening. wrenches to tighten nutson bolts. OVERLOAD RELAY: An electrical MECHANICAL CLEANING: Protective A method of device which autorhatically-tripswhen,a circuit cleaning the firesides of boilers byscraping and draws excessive current. wire-brushing. ,4A OXIDATION: Theprocess of various elements ROMHOS: Electricalunitsusedwith and compounds combiningWith salinity indicathrs tomeasure the conductivity oxygen. TI of water. corrosion of metals' is generallya form of oxidation; rust on iron, forexample, is iron oxide or oxidation. MOTOR GENERATOR SET: A machine which consists Of a motor mechanically p, , coupled PANT, PANTING: A seriesof pulsations to a generator and usually mountedon the same,. caused by minor, recurrent base. explosions in the firebox- of a ship's boiler.Usually caused by a shortage of air. NAVY BOILER COMPOUN A powdered chemical mixture used in boile w ter treatment PERIPHERY:Tire curved line which to convert scale- foi`tYli-ng, salts int forms the ludge. boundary of a circle (circumferepte),ellipse, or similar figure. NAVY SPECIAL OIL (NSFO):The - grade of fuel oil tat the Navy uses icombatant ships. "PITOMETER LOG:"Device that indicates the speed -of a 'ship and the distancetraveled by ieasuring water pressureon a tube projected NIGHT ORDER BOOK: Anoteb ok, outside the ship's hull. containingstanding andspecial, instructions from theengineerofficertothe -night PLAST-/CITY:. .engineering officer of the watch. That property which enablesa. material to be excessively and,perMan9tly, deformed without breaking. NITROGEN: An inert...gas which willnot" supportlife orcombustion. Used inrecoil PNEUMERCATOR: A type. of manometer systems-and other -spaces that requirean inert used to measure the,voltime atmosphere. of liquid in tanks. t PPM (parts per million):Comparison of the NONFERROUS METAL: Metalsthatare number of .parts- of a substance' composedprimarilyof .- some with a milli n elementOr parts of another substance. Usedto measure the elements other than iron. salt content of water. J OFFICER OF THE WATCH (00W):Officer PREHEATING: The application. on duty in the engineering spaces. of Mkt to the lase metal before itiselded or cut. 183 1.89 FIREMAN PRIME MOVER: The source of motionas a ROOT VALVE: A valvelocated where a turbine, automobile engine, etc. branch line comes off the main line. PUNCHING TUBES:Process for cleaning ,the ROTARY SWITCH: An electrical switch which interiors of boiler tubes. closes or opens the circujt by a rotating motion. RADIATION, HEAT: Heat emittedinthe ROTOR: The rotating part of a turbine,imp,mp, form of heat waves. or electric motor. REACHPRoDS:#X length of pipe or back stock SAE:Society of Automotive Engineers. used as an extension on stems. SAFETY VALVE: An automatic, .quick- REACTION TURBINE: A turbine in which the opening and closing valve which has a reset 'major part of the driving. force Is received from pressure, lower than the lift pressure. the reactiveforce of steam asitleaves the 1. blading. SALINITY:Relative salt content of water. REDUCER: Any coupling or fitting which SALINOM'ETER: A hydrometer that measures connects a large opt-King to a smaller pipe or the concentration of salt in a solution. hose. SAi,RATION PRESSURE: Thepressure REDUCING VALVES:Automatic valves that corr sponding to the saturation tem,peratdre. provide a steady pressure lower than the supply pressure. SATURATION TEMPERATURE: Temperature atwhichgliquidboilsundera given REDUCTION GEAR: A setof gears that pressure.Foranygivensaturationtem- transmit the rotation of one shaft to another peraturethere isacorrespondingsatura- a slower speed. tion pressure. REEFER: Aprovisioncargoshipora SCALE:Undesirable deposit, mostly calcium refrigeratedcompartment.Anauthorized sulfate, which forms in the tubes of boilers. abbreviation for refrigerator. SECURE: To make fast or safethe order REFRACTORY: Varioustypesofheat given on completion of a drill or exercise. The resistant,insulating material used to line the procedurefollowedwhenany pieceof insides of boiler furnaces. equipment is to be shut down. RE,FRIGERANT 12 (R-12):A, nonpoisonous SENTINEL VALVES:Small relief valves used gas usedin air conditioning and refrigeration primarily as a warning device. systems. SHAFT ALLEY:. The Pong compartment of a REGULATOR(gas): ,Aninstrumentthat ship in which the propeller shafts revolve. controls the flow of gases from compressed gas cylinders. SKETCH; A rodgh drawing indicating major features of an object to be constructed. R EMOTE OPERATlivG GEAR: Flexible cables attached to valve wheels so the,valves can SLIDING FEET: A mounting for turbines and be operated from anothencompartment. boilerswhichallowsforexpansionand 4 contraction. RISER: A verticalepipe leading off a large One. Example: a fireman riser. SLUDGE: The sediment left_in fuel oil tanks. 184 Appendix IGLOSSARY SOLID COUPLING:A device that joins two STRENGTH: The ability of a material to resist shafts rigidly. strain. . SOOT BLOWER: Soot removal device (fiat STRESS: A force which producesor tends to uses a steam jet to clean the firesides of a boiler. produce, deformation in a metal. SPECIFICHEAT: Theamountofheat required to raise the temperature of I pound of STUFFING BOX'. 'A device to prevent leakage a substance. 1°F. All substances are compared to between a moyitig and a fixed part in.asteam engineering plair( water which has a specific heat of I BTU /lb / °F. SPEED-LjMITING GOVERNOR: A device STUFFING TUBE: A packed tube that makes tlimitstherotational speed of a prime a watertight fitting for a cable or small pipe over. passing through a bulkhead. SPEED-REGULATING GOVERNOR: A SUMP: A container, compartment,or- reservoir, device that maintains a constant speedon a used as a drain or receptacle forfluids. piece of machinery thatisoperating under varying load conditions. SUPERHEATER: A unit in the boiler that drys the steam and raises its temperature. SPLIT ,PLANT: A. methodof °O rating propulsion plants so that theyare divided into SWASH PLATES:Metal plates in th; lower two or more separate and complete units. part of the steam drum that prevent the surging of boiler water with the motion of the ship_ _ SPRING BEARINGS:Bearings positioned at varying intervals along a propulsion shaft-to help SWITCHBOARD: A panelor group of panels,, keep it in alignment and to support its weight. with automatic piotective devices that distribute electrial power throughout the ship. STANDBY, EQUIPMENT: Twoidentical auxiliaries that perform onaunction. Whenone TAKE LEADS:- A method of determining auxiliary is running, the standby isso connected bearing clearance. that it may be started if the first fails. TANK TOP: Top side oank sectionor STATIC: A force exerted byreason of ight ,double bottom of a ship. alone as related to bodies at restor in bal'ce. STEAMING WATCH: Watches stood when the TDC (top dead center):The position* of a reciprocating piston at its uppermost point mainenginesareinuse and theshipis of underway. travel. STEAM LANCE: A devicethatuses low TEMPERING: -The heating and controlled cooling pressure steam to remove.3,--.;°t Cluin inside of ametal to produce the desired boiler's and to remove carbon from boilertubes. hardness. STEERING ENGINE: The machinery that THIEF SAMPLE:A sample 'Of bfl or water turns the rudder. taken frornla ship's tank for analysis. STERN TUBE: A watertight enclosurefor the THROTTLEMAN: Map in the engineroomwho rkerpeller Operates thethrottles tocontrol the main engines. STRAIN: The deformation,or change in shape, of a material which results from the weight of THRUST BEARING: A bearing that the applied load. limits the end play and absorbs the axial thrust ofa shaft. 185 FIREMAN TO BLOW TUBES:To use steam to remove VOID: et.small empty compartment Itow soot and carbdn from the tubes of steaming decks. boilers. VOLATILE:The term that describes a liquid TOP OFF:To fill up, as a ship tops off, with which vaporizes quickly. fuel oil before leaving port. VOLTAGE TESTER:A portable instrument _TOUGHNESS: The property of amaterial that4etects electricity. which enables it to w thstand shock as well as to be deformed withobreaking. WATER TUBE BOILER:Boilers in which the water flows through the tubes anis heated by . TRANSFORMER:An electrical device used to the gases of combustion. step up or step do an a-c voltage. WATER WASHING: A method of cleaning the TRICK WHEEL: A steering wheelinthe firesides of boilers to rerve soot and carbon. steeringengineroomoremergencysteering L station of a ship. WELDING LEAD: The conductor through which electrical current is transmitted from the TUBE EXPANDER: A toolthat expands power sOurcetotheelectrodeholder and replacement ,tubes intotheir seatsinboiler welding rod. drums and headers. a. WHELPS: Any of the ribs or ridges on the TURBINE: A multibladed rotor driven by barrel of a capstaQ or windlass. steam or hot gas. WIPED BEARINGS:A bearing in which the TURBINE JACKING GEAR: A motor-driven babbitt has melted because of excess heat. geararrangementthatslowlyrotatesidle propulsion shafts and turbines. WIREWAYS:Passageways betteen decks and on1he overheads of co artments that contain V TURBINE STAGE: One set of nozZles and the electric cables. succeeding row or rows of moving blades. WORK REQUEST:Request iced to naval UPTAKES (exhaust trunks): Large enclosed shipyard, tender, or repair ship for repairs.' passages for exhaust gases o rnovefromboilers to the stacks. ZERK FITTING:A small fitting to which a grease gun can be applied to force lubricating VENT: A valve in a tank or compartment that greaseintobearingsormoving _partsof primarily permits air to escape. machinery. VENTURI INJECTOR: A devic'e used to wash ZINC:A metal placed in saltwater systems tS the firesides of boilers. counteract the effects of electrolysis. tlf \) 492 s. l86 *44 0 APPENDIX II TOIEMETRIC SYSTEM The metric system was developed by French With the exception of the United States,-all scientists in 1790 and was specifically designed theindustrialized nations of the world have to be an easily used system of weights and adopted the -metric system. Even Englandand measurestobenefit science,industry, and Canada arechanging fromtheirtraditional commerce. The metricsystemiscalculated systems of measure, and the mptricsystem will entirely in powers of 10, soone need not work be almost universal by 1980. with the various mathematical bases usedwith Although the metric system hasnot been the English system, suchas 12 inches to a foot, officially legislated by the Congress, 3 feet to a yard, and 5280 feet to the metric a mile. systemisbecoming more prominent inthis The system is based on the "meter" whichis country. Most automobile mechanics one own somo ten-millionth of the distance from the metric, wrenches to workon foreign cars or Equator to the North Pole.It is possible to foreign components in American'cars. Almost all develop worldwide standards from this base df photographic equipmentisbuilttometric measurement. The metric system of weights is standards. Chemicals and drugs based on the gram, which is the weight are usually sold of a in metric quantities, and "caloriecounters" are specific quantity of water. using a metric unit of thermalenergy. Soonafterthe systemwasdeveloped Because we are allied with countrieswho use scientists over the world adopted it andwere themetricsystem, ableto deal much of Our military with the 'mathemaircs of their information isin,metric terms. Military mapsuse 'experimentsmoreeasily. Thedataand meters and kilometers instead of miles,and particulars of their work could be understoodby many weapons are in metric sizes, such other scientists anywhere in the world..During as 7.62 mm, 20 mm, 40 mm, 75 mm, and 155mm. the early 19th century many Europeannations Interchange of military equipment adopted the new system for engineering has caused a and mixtureofmetricand Englishmeasure commerce. It was possible for these countries to equipment since World War I whenthe army trade manufactured goods withone another adopted the French 75mm field gun, and World without worrying whether it would bepossible War II when the Navy procuredthe Swedish 40 torepairmachinery from another country mm Bofors and the Swiss 20 mm Oerlikon heavy withoutalsobuyingspecialwrenches and machine guns. measuring tools. Countries could buy andsell Itis inevitable that the United States machinetools will and othersophisticated and officially adopt the metricsystem. Exactly when precisionmachinery withouttroublesome this happens and how rapidly thechangeover modifications or alterations. It was much easier will depend on economics, sincethe expense of to teach the metric system, since meterscjn be retooling our industry andcommerce to new changefr-tcl kilometers or centimeters with\the measurements will be very great. The moveitent of a decimal point, which cost of is roughly conversion will be offset by increasedearnings like being able to convert yardsto miles or from selling machinery and products inches by adding zeros and overseas. a decimal instead of Another benefit is that scientistsuse the metric multiplying by 1760 or dividing by 36. system, but their calculationsnow have to be' 187 193 FIREMAN translated into English measure to be used by The basic quantities of the Metric system are industry. With adoption of the metric system multiplied or divided by powers of 10 to give ideas can go directly from the drawing board to other workable values. We cannot easily measure the assembly line. machine partsinterms of a- meter, so 'the The Navy will be using the metric system millimeter, or one-thousandth of a meter is used. more during the next few yioars. Although you For very fine measure thernicron, also called the will finditeasier to solve problems using this micrometur, can be used. It is one-millionth part system,atfirstyou willfinditdifficultto of a meter, or one-thousandth of a millimeter. visualize or to estimate quantities in unfamiliar For small,weightsthe milligram, one-thousandth units of measure. of a gramis used. All of these multiples are expressedwith standardprefixes taken from Fortunately many metricunits can be related to equivalent units in the English system. Latin: Themeterwhich isthebasic is I ,000,000 approximately one-tenthltonger than a yard. micro milli 1/1,000 ThebasicEmitof volume,theliter,is cent' 1/100 approxiMately one quart. The gram is the weight *deci 1/10 of a cubic centimeter, or milliliter, of pure water *deco 10 and is the basic unit of weight. As a common *hecto 100 weightthough, the kilogram, orkilo, which kilo I ,000 equals the weight of a liter of water, weighs 2,2 *myna 10,000 pounds. The cubic centimeter (cc) is used where mega 1,000,000 we would use the square inch. and where we measure by the fluid ounce. the metric system * Rarely used employs the milliliter (ml). For power measure the metric system uses the kilowatt (kW), which Over the next few years the metric system is approximately 1.3 horsepower. will become more used by the Navy as well as by In termsofdistance, a land n c is the civilian world. You will find it easy to work , eight-fifths of a kilometer and a nautical mile is with once you have mastered the basic terms. It 1.852 kilometers. or nearly 2 kilometer willbe difficultto translatvalues from our A basic metric expression of pressure the present system to the metric s m, but this kilogram per square centimeter, which is4.2 operation will become unpecessary oe the new psi. nearly I atmosphere of pressure. measurements are totally adopted. When working on foreign machinery, you Tables of equivaleriT English measure and may noticethatyour-half-inch, three-quarter metric equivalents are essential when you work inch, and one-inch wrenches will fit many of the simultaneously with both systems. The table bolts. These sizes correspond to 13 mm, 19 mm, which follows shows the equivalent measures of and 2mm respectively in the metric system, the two systems. The columns on the left have and are very popular use they are the equivalent values which are accurate enough interchangeable.The I af nch sparkplug formostwork. and onthe rightarethe wrench, which is standar this country, is multiples used to convert the values with a high intended to fit a 20 mm n 'degree of accuracy. 194 188 /e Appendix IITHE METRIC SYSTEM THESE PREFIXES MAYBE APPLIED TO ALL SI UNITS Vittipla sad SmbewItip Iss Prefize3 Symbols 1 000 000000 000=10"tera (WO T 1 000000 000=10' giga (Pgif) G 1000 000=10' mega (megler) M i 000=10' kilo (kill) k 100=101 hecto (helet6) h 10=10 deka (deed) da 0.1=10-'deci (des% d 0.01=104centi (seta) c 0.001=10-'milli (mill) m 0.000 001=104micro (mi'krii) AL 0.000000 001=10nano (nan16) n 0.000 000 000001,=1041pico (pesk6) p 0.000 000 000000 001 10-"femto (fernsto)f 0.000 000 000 000000 001=104'atto (ert6) a Most commonly mut 195 189 FIREMAN e Multiply By To Obtain Multiply By To Obtain Acres 40.41 Ares Feet . 30.48 Centimeters Acres 4,041 Centares- Feet 0 1661 Fathoms Acres 10 Square chains Feet 0.3048 Meters, Acres 43,560 Square Feet Feet per Minute 0 01136 Miles per Hour Acres 1,840 Square Yards. Feet per Second 0 5921 Knots Ares 0 02411 Acres Feet per Second 18.288 Meters per Minute Ares 100 Centares Feet per Second 0.6818 Miles per Hour Ares 1,076 Square Feet Furlongs 10 Chains Ares 119.6 Square Yards Furlongs 660 Feet Barrels (U.S., dry) 3.281 Bushels Furlongs 40 Rods Barrels (U.S., liquid) 4.21 Cubic Feet Furlongs 220 Yards .. Barrels (U.S., liquid) 31.5 - Gallons Gallons (British) 4,546.1 Cubic Centimeters Board Feet (1' x 1' x 1') 144 Cubic inches Gallons (British) . 0 1605 Cubic Feet Cable lengths (U.S.) 120 Fathoms Gallons (British) 211.214 Cubic Inches Cable lengths (U.S.) 120 Feet Gallons (British) 1.2009 Gallons (U.S.) Cable lengths (U.S.) 240 Yards Gallons (British) 4.546 Liters Centares 10.16 Square lel Gallons (British) 4 Quarts (British) Centares 1.196 Square yards Gallons (U.S.? 0 03115 Barrels (hold, U.S.) Centimeters 0 3931 Inches 3,185.4 Cubic Centimeters Cubic Centim'eters 0 06102 Cubic Inches Gallons (U.S.) 0 13368 Cubic Feet Chains 66 Feet Gallons (U.S.) Gallons (U.S.) 231 Cubic Inches Chains 100 Links Gallons (U.S.) 0 8327 Gallons (British) Chains 4 Rods 3.185 Liters Cubic Feet 1,128 Cubic Inches Gallons (U.S.) Gallons (U.S.) 4 Quarts IU.S.) Cubic Feet 0 02832 Cubic Meters 15.43 Grains Cubic Feet 0 03104 Cubic Yards Grams Grams 0 001 Kilograms Cubic Feet 6.229 , Gallons (British) Grams 1,000 Milligrams Cubic Feet 1.481 Gallons (U.S.) Grams 0.035,2? Ounces (ayon Cubic Feet 28.316 Liters dupois) Cubic Inches 16.39 Cubic Centimeters Hands 10.16 Centimeters Cubic Inches 0 0005181 Cubic Feet Hands 4 Inches Cubic Inches 0 003606 Gallons (British) Hectares 2.471 Acres Cubic Inches 0 004329 Gallons (U.S.) Hectares 100 Ares Cubic Inches 401639 Liters Hectoliters 0 1 Cubic Meters Cubic Meters 35,S.1 Cubic Feet Hectoliters 26.411 Gallons (U.S.) Cubic Meters L308 Cubic Yards Hectoliters 100 Liters Cubic Yards 21 Cubic Feet t .. Hogsheads 2 Barrels (Liquid, Cubic Yards 0 1646 Cubic Meters U.S.) Cubic Yards 164.6 Liters Hogsheads (U.6.) 63 Gallons (U.S.) 1 Degrees (C.)+ 11.8 1.8 Degrees (F.) Hundredweights 0 508 Quintals (metric) Degrees (F.) -32 0 5556 __.DZees(C.) .. Inches 12 Points (:),e-grees , 0 01145r Rad)ons Inches 6 Picas Fathoms 0.00833 Cable Lengths (U. 6 Ems S.) Inches Inches 12 Ens Fathoms ti Feet Inches 2.54 Centimeters Fathoms 1.8288 Meters 196 O 190 9 Appendix II THE METRIC SYSTEM Multip ly By To Obtain Multiply By To Obtain Inches 0.0833 Feet Miles, Nautical 6,016.1 Feet Inches 1,000 Mils Miles, Nautical 72,363 Inches Inches 0.0277 Yards Miles, Nautical 1.8532 Kilometers Inches of Mercury 0.49131 Pounds per Square Inch Miles, Nautical 5 1,853.2 Meters Kilograms 1,000 Grams Miles, Nautical 1.1508 Miles, Statute Kilograms 2.2046 Pounds (Avoir- . Miles, Nautical 1 Minutes.of dupois) Latitude Kiloliters .1 / Cubic Meters Miles, Nautical 2,026.8 Ys Kiloliters 1.300 Cubic Yards Miles per Hour Off Fe Si per Minute , Kiloliters 264.18 Gallons (U.S.) (Statute) Kiloliters 1,000 Liters Miles per How 1.467 Feet per Second Kilometers 4.557 Cable Lengths (Statute) Kilometers 3,280.8 .Feet Miles per How 0.8684 Knots Kilometers , 39,370 Inches Miles, Statute 7.33 Cable Lengths Kilometers 1,000 Meters Miles, Statute 5,280 Feet Kilometers 0.5396 Miles, Nautical Miles, Statute 6 8 48 Furlongs Kilometers 0.62137 Miles, Statute Miles, Statute 63,360 Inches Kilometers 1,093.6 Yards Miles, Statute 1.6093 Kilometers . Knots 1.1516 Statute Miles per Miles, Statute 1,609.3 Meters How Miles, Statute 0.8689 Miles, Nautical Knots ,1.688 Feet per Second Miles, Statute 1,760 Yards. Leagues, frautical 25.33 Cable Lengths Millier (See Tons - Leagues, Nautical 5.5597 Kilometers Metric) , Leues, Nautical 3 Miles, Nautical Milliradians 206.265 Seconds of Arc Leagues, Statute 4.8280 Kilometers Mils 0.001 Inches Leagues, Statute 3 Miles, Statute , Myriameters 10 Kilometers Links 7.92 Inches Ounces (avoirdupois) 28.3495 Grams Liters 1,000 Cubic Centimeters Pint (Liquid, U.S.) 4 Gills (U.S.) Liters 61.025 Cubic Inches Pint (Liquid, Br.) 4 Gills (British) Liters 0.21998 Gallons (British) Pint (Liquid, Br.) 0.56825 Liters ,Liters 0.26418. Gallons (U.S.) Pint (Liquid, U.S.) 0.4732 Liters Liters , 0.8799 Quarts (British) Pounds (avoirdupois) 7,000 Grains Liters 0.908 Quarts (U.S.,dry) Pounds (avoirdupois) 453.59 Grams Liters . 1.0567 Quarts (1-00. Pounds (avoirdupois) 0.4536 Kilograms U.S.) Pounds (avoirdupois) 16 Ounces Meters 100 Centimeters Pounds (avoirdupois) 1.2153 Pounds (troy) Meters 0.001 Kilometers' Pounds (troy) 0.8229 sounds (avoir- Meters 1.0936 Yards dupois) Meters 3.281 Feet Pounds per Square Inch 2.03537 Inches of Meters 39.37 Inches Mercury Meters 1,000 Millimeters Quart (British) 1.1365 Liters Meters 1.0936 Yallit'. Quart (British) 2 Pints (British) Meters per Minute 0.0541 Feet per Second Quart (Liquid, U.S.) 0.9463 Liters Meters per Second 2.237 Miles per Hour Quart (U.S.) 2 Pints (U.S.) Microns 0.001 Millimeters Quintals (Metric) 1.97 Hundredweights Miles, Nautical 8.44 Cable Lengths Quintals (Metric) 100 Kilograms 197 191 1 'N. FIREMAN ) Multiply By To Obtain Multiply By To Obtain Radians 57.30 Degrees Square Miles, Statute 259 Hectares Rods Feet 16:3 Square Miles, Statute 2.59 r Square Kilometers Rods 25 Links Square Yards '-0.8362 Centares Square Centimeters Square Inches 1;1550 Square Yards 9 Square Feet Square Feet Centares 0.b929 Square Yards 1,296 Square Inches Square Feet 929 Square Centimeters Tpns (Long), 1.016 Metric Tons Square Feet 144 s Square Inch -.J Tons (Long) 2,240 Pounds (Avoir- Square Feet 0.1111 Square Yards dupois) Square Inches 6.452 Square Centimeters Tons (Metric) 1,000 Kilograms Square Inches 0.006944 Square Feet . (Millier) Square Kilometers . 100 Hectares ,Tons (Metric) 2,204.6 PdAls (Avoir- Square Kilometers 0.3861 Square Miles (Whe) dupois) (Statute) Tons (Short) 0 9072 Metric Tons Square Meters (See Tons (Short) 2,000 Pounds (Avoir- Cen tares) dupois) Square Miles, Statute 640 Acres Yards 91.44 Centimeters Square Miles, Statute 25,900 Ares Yards 0.9144 Meters O 198 192 lr INDEX A elassification.of boilers, 62-65 , furnace arrangement, 65 A-c generators, 144-146 location of fire and water spaces, 62 Advancement, preparing for, 1-4 type of superheater, 65 Advancement rewards, 4 types of circulation, 64 Air compressors, 94 Cold-iron watch, 172 Air conditioning equipment, 89 Combustion, 28 Air registers, 62 Condensatiorerb Anchor windlass and capstan, 92 Constant-pressuiRiumpgovernors,. 125-128 Appendix I, glossary, 177-186 Converting power to drive, 38* Appendix II, metric system, 187-192 clutches and reverse gears, 44r-46 Assembly, boiler, 56-60 reduction gears, 39-41 Atomizers, 60 Cranes, 95 Auxiliary machinery and equipment, 88-99 Auxiliary steam cycle, 53-55 D B D-c generators and exciters, 144 Damage control assistant, 8 Basic steam cycles, 48-55 Diaphragm gages, 103 Batteries, 151 Diesel-driven generators, 146 Battle lanterns, 151-153 Diesel electric drive, 35 Bellows gages, 103, Diesel engine drive, 36-38 Bimetallic dial thermometers, 104 Diesel engines, 158-165 Blowerman, 173 air sOtem, 160 Boiler assembly, 56-60 'cooling system, 163 Boiler technician (BT), 12 fuel system, 161 o. Boilermaker (BR), 13 lubrication system, 162 Boilers,'6-71 power system, 159 1 Boilers, classification of, 62-65 starting systems, 164 Boilers, new high-pressze, 68-70 valve mechanism, 160 Bourdon tube gages, 100-103 Diesel-powered boat operation,, 69 .Burnerman, 173 Distant-reading dial thermometer, 104 Burners, fuel oil, 60-62 Distilling plants, 90 C E Electric motors, 150 Capstan and anchor windlr 92 motor controllers, 151 Checkman, 173 d-c and a-c motors, 1 193 199 FIREMAN Electrical equipment, shipboard, 143-155 Electrical officer, 8 Electrical safety precautions, 154 Gage glasses, 106 Electrician's Mate (EM), 13-15 Galley equipment, 99 Electricity introduction, 143 Gas-free engineer, 9 electric current, 143 Gas turbine engines, 166 -169 electromotive force, 143 comparison of gas turbines and resistance, 144 reciprocating engines, 167 watt, 144 components of gas turbine engines, 168 Elevators, 96-98 Gaskets and packing, 137 Energy, 18 Gasoline engines, 165 Engineer officer, 5 (;eared- turbine drive, 31-33 Enginernan (EN), 11 Generation, 49 Equipment, portable, 151-153 Generator and distribution switchboards, 148 Evaporator watch, 175 Generator types and drives, 144-147 Expansion, 49-51 a-c generators, 144-146 Engineering department, 5-16 d-c generators and exciters, 144 Engineering department organization, 5-10 diesel-driven generators, 146 Engineering department ratings, 10-16 . ship's service turbine-driven generators, 146 boilermaker (BR), 13 Glossary, appendix I, 177-186 boiler technician k BT), 12 electrician's mate (EM), 13-15 engineman (EN), 11 H hull maintenance technician (HT), 15 interior communications eleetrician (IC), 15 High-pressure boilers, new, 68-70 Hull maintenance technician (HT), 15 machinery repairman (MR), 12 Hydraulics principles, 22-24 machinist's mate (MM), 10 molder (ML), 15 patternmaker (PM), 15 Engineering fundaentals, 17-30 Engineering instrum nfttl 12-115 Information sources, 3 engiii e order tel aph, 114 Instruments, 100-115 lube oil pressure alarm, 114 Interior communications electrician (IC), 15 salinity indicator, 113 Internal combustion engines, 156-170 smoke indicator, 113 steam flow indicator, 112 superheater temperature alarms, 112 L Engineering watches0171-176 Laundry equipment, 99 Lighting distribution systems, 154 F Liquid lei/el indicators, 106 Feed, 51-53 gage glasses, 106 Fire marshal, 9 tank gaging system, 106 Fireman rate, 1-3 Liquid-in-glass thermometers, 104-106 Fireroom safety precautions, 70 bimetallic dial thermometers, 104 Fluid meters, 107-109 J distant reading dial thermometers, 104 Force, 17 pyrometers, 105, Fuel oil burners, 60-62 Lovvei level watches, 174 air registers, 62 lube oil pump, 174 atomizers, 60 main .c)ndensate pump, 175 Furnace arrangement, 65 200 main feed pump, 174 -0,, 194. INDEX Lube oil pressure alarm, 114 P Lube oil purifiers, 93 Lubrication, 84-87 Packing and gaskets, 137 Patternmaker (PM), 15 ;), M Physics, 17-29 combustion, 28 energy, 18 MachineryV equipment, auxiliary, 88-99 Fl Machinery repairman (MR), 12 force, 17 Machinist's mate (MM), 10 laws of gases, 19 Main propulsion assistant, 7 mass, weight, and inertia, 17 Main propulsion, double-reductiongearing, power, 19 81-83 pressure and vacuum, ;0-22 Main steam cycle, 49-53 principles of hydraulics, 22-24 condensatiog, 51 principles of pneumatics, 24-27 expansion, 49-51 ,...speed, velocity, and acceleration, 17 feed, 51-53 steam, 29 generation, 49 temperature, 27 Manometers, 103 work, 18 Messenger of the watch, 171 Piping, 134-137 Metals, 29 pipe fittings, 136 - Meters, fluid, 107-109 piping definitions, 134-136 Metric system, appendix II, 187-192 piping materials, 136 Molder (ML), 15 Pneumatics principles, 24-27 Portable equipment, 151-153 N battle lanterns, 151-153 portable extension lights, 153 NBC defense officer, 8 portable tools, 153 Naval boilers, other, 65-68 sealed beam lights, 153 New high-pressure boilk,rs, 68-70 Power distribution systems, 15e Preparing for advancement, 1-4 0 Pressure gages, 100-10V bellows gages, 163 Operation of small boat engines, 169 .s? Bourdon tube gages, 100-103 diesel powered boat operation, 169 diaphragm gages, 103 gasoline engine operation, 170 manometers, 1()3 Organization of engineering department, 5-10 damage control assistant, 8 }Principlesof ship propulsion, 31 department administrative assistant, 6 Propeller, 46 department fra.ining officer, 7. Propulsion, ship, 31-47 division officeri, 9 Propulsion units, typical, 31-38 electrical officer, 8 Pump governors, constant-pressure,125-128 engineer officer, 5 Pumps, 116-125 enlisted personnel, 9 centrifugal, 122 fire marshal, 9 jet0124 gas-free engineer, 9 propeller, 123 main propulsion assistant, 7 4. reciprocating, 117-121 NBC defense officer, 8 rotary, 121 technical assistants, 9 Pyrometers, 1105 195 201 FIREMAN R T. Ratings, engineering department, 10-16 Tank gaging system, 106 Reciprocating engines, 156-158 Thermometers, liquid-in-glass, 104-106 ignition principles, 156 Thermometers and pyrometers. 103 operating cycle, 156-158 Throttle watch, 173 Reduction gears, 39-41, 81-87 lubrication, 84-87 Turbines, 72-81 main propulsion, double-reduction classification of turbines, 72-77 construction of turbines, 77-81 gearing, 81-83 reduction gear construction, 83 Turboelectric drive, 33-35 Refrigeration equipment, 88 Resistance, 144 Typical propulsion units, 31-38 Reverse gears and clutches, 41-46 diesel electric drive, 35 , Revolution counters and indicators, -109-112 diesel ehgine drive, 36-38 geared-turbine drive, 31-33 turboelectric drive, 33-35 S Safety precautions, electrica1,154 Safety precautions, fireroom, 70 Upper level watch, 175 Salinity indicator, 113 Sealed beam lights, 153 V Shaft alley watch, 175 Ship propulsion, 31-47 Vacuum and pressure, 20-22 Ship propulsion principles, 31 Shipboard electrical equipment, 143-155 Valves, 128-134 Shipboard electrical systems and connections, check, 130 153 reducing, 133 lighting distribution systems, 154 relief, 132 power distribution systems, 154 safety, 134 shore power connections, 154 stop, 128-130 Ship's service turbine-driven generators, 146 stop-check, 131 Small boat engines, operation of, 169 throttle, 132 Smoke indicator, 113 Sounding and security watch, 171 soundings, 172 Steam, 29 Steam cycles, basic, 48-55 Watch, 171-175'4 Steam flow indicator, 112 cold-iron, 172 Steam traps and drains, 140-142 evaporate, 175 Steam turbines and reduction gears, 72-87 lower level, 174 Steering gears, 91 messenger, 171 Strainers, 137-140 shaft alley, 175 Superheater temperature alarms, 112 throttle, 173 Superheater, type of, 65 upper level, 175 Switchboards, 147-150 Watch messenger, 171 components of a switchboard, 148-150 Watches,engineering, 171-176 generator and distribution switchboards,' Watt, 144 14 Winches, 98 196 2O2 OCCUPATIONAL STANDARDS Firemen,(FN) train for one of the generalor, service ratings of Engineering and Hull Group VII. Firemen stand messenger, cold iron, and fire watches;clean engineering spaces and eq3ipment; make minor repairs to engineering equipment; recordreadings of gages; participate in general drills; and perform general detail duties. 40( The observance of proper safety precautions in allareas is an integral part of each billet and the , responsibility of every Navy man and woman: therefore, it is a universal requirement forall ratings. OCCUPATIONAL STANDARDS ei Covered in Assignment 25 NAVAL ORIENTATION AND ORGANIZATION 25251 Identify organizational structure of the engineeringdepartment 1 28 TECHNICAL DRAWINGS 28286 Read a three-view working drawing 28287 Use damage-control drawings to locate principalvalves in main 1,4,5 steamline .4 ft 30 MECHANICAL MAINTJOPERA -AUX EQUIPMENT 30609 Locate refrigeration equipment, anchor windlasses, distilling 4,5 plants, compressors, steering engines, cranes, elevators,winches, and the following pumps: fuel oil service, fueloil transfer, fire rand flushing, fire and bilge, main lubricating oil,fresh water,, condensate, main circulating, main feed,'main feedbooster, acrd emergency feed pump 30610 Operate centrifugal and reciprocatingpumps using checkoff 4,5 sheet 30611 Define functions of the folloWing auxiliaryequipment: air 4,5 _ compressors, distilling plants, refrigeratiaplants, fuel oil heaters, lube oil coolers, main and auxiliary condensers,air ejector condenser assembly,a.c. and d.c. generators and motors, and pumps . 197 203 OCCUPATIONAL STANDARDS - Covered .in 'Assignment 31 MECHANICAL MAINT/OP,ERA-PROPULSION 0 31376 Read fuel, water, oil, air and steam'gages, indicators, and thermometers 31377 Identify basic types and component parts of: A. Naval boilers B. Steam turbines C. Reduction gears D. Propeller and shafting E. Shipboard electrical systems F. Internal combustion engines -31378 Define functions of valves found in engineering systems 31379 Pealikm functions of boat engineer_ 1 .31380 Replace gaskets and repack valves in law pjessure steam and 5, water piping systems c. 31381 Perform minor ejgine maintenance . ,6 ) \ 31382 Trace path of main steam from boiler to engine and back to 1,4,5 boiler, naming eitial fittings, piping, and main machinery through which it 31383 Define principles of maiTand auxiliary steam cycles,\ 2 31384 Define basic principles of: A. Mass, weight, and inertia 1,2 B. Force energy, and power 1,2 C. ,.velocity, and acceleration 1,2 D. Pressure and vacuum 1,2 E. Hydraulics And pneumatics 1,2 F. Combustion, heat, and temperature 1,2 31385 Recognize common engineering terms and nomenclature 31386 Assist in perfornfance ormaintenance.using maintenance, requirement cards (MRC) '31387 Use weekly 3-guschedule to determine maintenance assignments 38 ADMINISTRATION 1 38001 File- shlip's blueprints 2 0 4. 198 , OCCUPATIONAL STANDARDS Covered in Assignment 42 GENERAL WATCHSTANDING 422421 Stand following engineering watches: A. Fire watch f 6 B. Messengerc:' 6 C. Cold iron 6 D. Sounding and security watch 6 4243 Maiin required records atwatch station 94 MECH i ICAL MAINTENANCE 94368 Use and maintainhandtools 4r 94369 Use lubricating oils and greises 3 ' I Jo' 205 199 ff FIREMANI . NAVEDTRA 10520-E Prepared bythe Naval Education and Training Program Development Center,_ Pensacola, Florida 4 Your NRCC contains A set of assign- higher. If you are on active duty, the ments and self-scoring answer sheets averageof your grades in all assign- (packaged separately). Tt)e Mate Training ments must be at least 3.2. If you are Manual"Fireman, NAVEDTRA 10520-E, is NOT on active duty, the average of your your textbook for the NRCC. If an errata grades in all assignments of each sheet comes with the NRCC, ma e allindi- creditaable unit must be at least 3.2. cated changes or correttions.. not The unit breakdown of the course, if change or correct the textboolc ssign- any, is shown later under Naval Reserve iments in any other way. Retirement Credit. WHEN YOUR.COURSE IS ADMINISTERED HOWTOCOMPLETETHIS COURSE SUCCESSFULLY BY LOCAL COMMAND Stud e textbobk pages given at As soon as you have finished an the begi nin of each assignment before assignment, submit the completed self- trying o an wer the items. Pay attention scoring answer sheet to the officer to tabte an ustrations as they designated to administer it. He will contain a lot of information. Making your% chock the accuracy of your score and own drawings can help you understand the discuss with you the items that you do subject matter. Also, read the .learneng not understand. )(Cod may wish to record objectives that precede the sets of items . your score on the assignment itself since The learning objectives and items are the self-scoring answer sheet is not based on the subject matter or study returned. material in the textbook. The objectives tell you what you should be able to do If you are completing this NRCC to by studying assigned textual material become eligible to take the fleetwide and answering the items. 7" advaricement examination, follow a schedule that.will.,enable you to complete At this point you should be ready all assignments in time. Your schedule 4 to answer the items in" the assignment. Should( call for the completion of at Read each item carefully.aSelect the least bne assignment per month. BEST ANSWER for each item, consulting your textbook when necessary. Be sure Although you complete the course to select the BEST ANSWER from the successfully, the Naval Education and . subject matter in the textbook. You may Training Program Development Center will discuss difficult points in the course not issue you a letter of satisfactory ,with others. However, the answer you completion. Your command will make a note. select must be your own. Use only the in your service record, giving you credit self- scoring answer sheet designated for your work. for your assignment. Follow the scoring directions given on dhe answer sheet WHEN YOUR COURSE IS ADMINISTERED itself and elsewhere in this course. BY THE NAVAL EDUCATION AND TRAPIING PROGRAM DEVELOPMENT CENTER Your NRCC will be administered by your command or, in the case of small After finishing an assignment, go commands, by the Naval Education and on to the next. Retain each completed 'Training Program Development Center. self-scoring answer sheet until you No matter who administers your course finish all the assignments in a unit (or you can complete it successfully by in the course if it is not divided into earning gradeS that average 3.2 or units). Using the envelopes provided, 206 mail your aelf-ocoreki answer oheetOtO theNAVAL RESERVE RETIREMENT CREDIT Naval Education and Training Program Development Center where the scores will This course is evalUated at 10NaVal be verified and recorded. Make oure all Reserve retirement points. These points blanks at the top of each answer sheet are creditable to personnel eligible to are filled in. Unless you furnish all the receive them under current directives information required, it will be governing retirement of Naval Reserve impossible to give you c edit for your personnel. Points will be credited upon work. You may wish to rec rd your scores satisfactory completion of the entire on the assignments since e oelf-ocoring course. answer oheetn are not returned. The Naval Education and Training 4 Program Development Center will issue a letter of satisfactory completion to certify successful completion of the course (or a creditable unit of the course). To receive a course-completion letter, follow the directions given of the course-completion form in the back of this NRCC. You may keep the textbook and assignments for this course. Return them only in the event you disenroll from the course or otherwise fail complete the ODURSE 011IECTIVE course. Directions for re urning the textbook and assignments are given on the When you complete this course, you book-return form in the back of this will halt abroad concept of how the NRCC. engineering plant works from the beginning of the steam.cycle in the fireroom through PREPARING FOR YOUR ADVANCEMENT the engineroom and return to the fireroom. EXAMINATION You will have a general knowledge of the piping and auxiliary systems needed to Your examination for advancement is operate a steam plant. You will have a based on the Manual of Navy Enlisted Man- broad view of the electrical distribu- power and Personnel Classification and tion system, damage control, and small' Occupational Standards (NAVPERS 18068-D). boats. You will have been introduced The sources of questions in this examine- to the engineering'Iplant organization tion,.are given in the Bibliography for Ad-and the types of watches stood by vancement Study (NAVEDTRA 10052). Since engineering personnel. your NRCC and textbook are among the sources listed in this bibliography, be sure to study both in preparing to take your advancement examination. The stand- ards for your rating may have changed since your course and textbook were printed, so refer to the latest editions of NAVPERS 18068-D and NAVEDTRA 10052. While working on this nonresident career course, you may refer freely to the text. You may seek advice and instruc- tion from others on problems arisingin the course, but the solutions submitted 4 must be the result of yourown work and -. decisions. You are prohibited fromre- ferring to or copying thesolutions of others, or giving completed solutionsto anyone else taking thesame course. 207 ii Naval nonresident career courses may include a variety of items multiple-choice;lue-falSet . matching, etc. The items are not grouped by type; regardless of type, theyare presented in the same general sequence as be textbook material upon which they are based. This presentation is designed to preserve continuity of thought, permitting step-by-step development of ideas. Some courses use many types of items, others only a few. The student c4n readily identify the type of each item (and the action required of him) through inspection of the SampIes given below. MULTIPLE-CHOICE ITEMS Each item contains several alternatives, one of which provides the bestanswer to the item.. Select the best alternative and erase the appropriate x on the answer sheet. SAMPLE s-1. The first person to be appointed Secretary of Clefense The erasure of a correct answer is in- under the National Security Act of 1947 was dicated in this way on the dhswer sheet: 1. George Marshall 2. James Forrestal 3. Chester Nimitz 4. William Halsey s-i°II I I TRUE-FALSE ITEMS Determine if the statement is true or false. If any part of the statement is false the state- ment is to be considered false. Erase the appropriate box on the answer sheet as indicated below. SAMPLE The erasure of a correct answer is also s-2. Any naval officer is authorized to correspon indicated in this way on the answer officially with a bureau of the Navy Department sheet: without his commanding officer's endorsement. 2 L_ MATCHING ITEMS IS -2 CC Each set of items consists of two columns, each listing words, phrasesor sentences. The task is to select the item in column B which is the best match for the item incolumn A that is being considered. Specific instructions are given with each set of items. Select the numbers identifying the answers and erase the appropriate boxes on the answer sheet. SAMPLE In items s-3 through s-6, match the name (7-IFi shipboard officer in column A by selectingfrom column B the name of theNepartment in which the officer functions. A. Officers B. Departments The erasure of a correct answer is in- dicated in this way on the answer sheet: s-3. Damage Control Assistant 1. Operations Department s-4. CIC Officer 2. Engineering Department s-5. Assistant for Disbursing * 3. SupplyDepartment s-6. Communications Officer How To Score Your Immediate Knowledge ofResults (IKOR) Answer Sheets Total the number of in- Sample only T F correct erasures (those Number of boxes that show page numbers) erased incorrectly 0-2 3-7 9 9 for each item and place C in the blank space at Your score 4.0151) 12 the end of each item. Now TOTAL the column(W6f incorrecterasures and find your score in the Table at the bottom of EACH answer sheet. NOTICE:If, on erasing, a page numbe,r appears, review text (staFting on that page) anderase again until "C", "CC", or "CCC" appears. For courses administered by the Center,the mdximum number of points (or incorrect erasures) will bededucted from each item which does NOT have a "C", "CC", or "CCC" uncovered (i.e., 3 pts. for fourchoice items, 2 pts. for three choice items, and -1 pt. for T/F ieema). iii 208 lo Assignment 1 Preparing for AdvanceneVIssAngineering Department and Enghaporing Fundamental° Textbook Asaignment: Chapter° 1,2, and 3 In this couroo you will demonotrato that learning hao takenplace by correctly anowering teach- ing item°. Tho mere phyoical act of indicating a choiceon an answer ohoot io not in itself impor- tant; it io the pentrq achievement, in whatever formit may take, prior to the physical not that io important and toward which nonreoidentcareer couroe learning objectives are directed. The °election of the correct choice for a nonreoidentcareer course teaching item indicate° that you have ful- filled, at leant in part, the nted objective(n). Tho accomplishment of certain objective°, for example,a Alynical act ouch ao drafting a memo, cannot readily bo determined by means of objectivetypo nonresident career course items; however, you can demonotrate by means of anowero to teaching items thatyou have acquired the requiaite knowledge to perform the phyoical act. The accomplishment of certain other learning objeotivea, for example, the mental. act° of comparing, recognizing, evaluating,ohooping, selecting, etc., may be readily domonotrated a nonresident career courne by indicating the correct answersto teaching items. The com re enoive objective for thiaoourae has already been given. It atatea the purpose of the oourae terms of what you will be able to do ac you complete theoourae. The de iled objectives in each aaaignment state whatyou ahould accomplish aa you progress through the course. They may appear aingly or in clusters of olooely relatedobjectives, aa appropriate; they are followed by items which will enableyou to indicate your accomplishment. All objectives in this course are learning objectives and items are teaching items. Thry point out important thinga, they assist in learning, and theyshould enable tyou to do a Letter JA for the Navy. This aelf-atudy course is only one part of the totalNavy training program; by .1.3 very aature it can take you only part of the way toa training goal. Practical experience, achools, selected reading, and the desire to accompliahare also neceasary to round out a fully meaningful training program. 1-3. The petty officers you assist aboard ship will give you opportunities to perform Learning Objective: Recognize the gen- tasks on your°own before showing yol.ektow eral duties of a Fireman and identify to do them. the bagic military and professional requirements for advancement. Textbook 1-4. The knowledge factors of a professional or pages1 through 4. a military requirement for advancement are subdivisions of the requirement that specify the 1. mental skills one must have to 1-tl. A Fireman trains forwhat group of ratings? perform the duties of the rating 1. Ordnance 2. physicalskills one must have to 2. Operations perform the duties of the rating 3. Supply 3. performance tests one must pass 4. Engineering 4. physical skill tests one must pass 1-2. Aboard ship, the tasks performed by a 1-57 The qualification standards for advance- Fireman include standing security and ment in rating listed in the Manual of fire watches in the engineering spaces Navy Enlisted Manpower and Personnel and serving as messenger for damage Classifications and Occupational Standards control repair parties. are the 1. maximum requirements 2. average requirements 3. minimum requirements 4. suggested, but not necessary require- ments 1 209 1-6. Which.of the following publications [Mould 1-12. Which of the following publications will you consult to find the military and pro- be useful to you when you study for foot:lona' requirements for advancement? advancement in rating? 1. NAVSEA Journal 1. Tools and Their Uses 2. Manual of Navy Enlisted Manpower and 2. Blueprint Reading and Sketching Personnel Classifications and Occupa- 3. Rate Training Manual tional Standards 4. All of the above 3. List of Training Manuals and Corre- spondence Courses 4. Basic Military Requirements ' Learning Objective: Identify the administrative and operational 1-7. Before you can take the examination for functions of the engineering depart- - advancement, there must be en entry in ment and the eleven Group VII ratings. your service record to prove that you have Textbook pages 4 through 16. qualified in the 1. professional qual orations 2. knowlege factors 3. military qualifica ons 1-13. Men assigned to the engineering department 4. practical factors will probably be called upon to repair which shipboard equipment? 1-8. Upon being transferred another duty 1. Computers station, you should make sure that your 2. Electric motora NAVEDTRA 1414/1 is 3. Fire control radar sets 1. among your personal papers 4. Loran gear 2. retained by your division officer 3. destroyed and a new one started at 1-14. Assists is to the engineer officerLally your new duty station inc lud the in your-rarvice record 1. dage control assistant, repair cP officer, and electronics officer 1-9. The final requirement that must be met 2. electrical officer, main propulsion before you are eligible to take the assistant,sand damage control, examination for advancement is 'the assistant 1. required length of service in pay grade 3. main propulsion assistant, C division 2. satisfactory completion of the prac- officer, and electricalOofficer tical factors for the next higher rate 4. damage control assistant, operations 3. completion of training manuals for the officer, and the main propulsion next higher rate assistant 4. recommendation by your commanding officer 1-15. The duties and responsibilities of the engineer officer are established by 1-10. A recommended publication for finding . 1. the Chief of Naval Personnel titlesof reference materials to help 2. the commanding officer you prepare for your servicewide exami- 3. the Naval Ship Engineers enter/ nation is the latest-revision of 4. U.S. NavyRegulatiorlf 1. Bibliography for Advancement Study 2. NAVSHIPS Technical Manual 1-16 Who aids the engineer officer by screening 3. Manual of Qualifications for Advance- all his incoming mail and controlling the ment in Rating issuance of directives which he has 4. Military Requirements for Petty released? Officer 3 and 2 1. Engineering department administrative assistant 1-11. How will you rqpognize the training 2. Leading Yeoman assigned to the manuals in the Bibliography for Advance- engineering department ment Study that you must complete 'to 3. Leading Yeoman assigned to,the ship's come eligible to take an examination office fo vancement? 4. A technical assistant assigned to the 1. They are listed by title in especial engineering department column under your rating 2. Their titles are each marked with a dagger 3: They are listed by title ''in a,"manda- tory completion" column 4. Their titles are marked with asterisk 2,;.0 , 1-17. In a typical organization of a large 1-22. Tate training of personnel to fightfirms nhip's engineering department, the main oard nhclip is administered by the' propulsion assistant, the damage control 1. ship's training officer assistant, and the electrical officer are 2. damage control assistant responsible to the 3. adminintrative.annistant to the 1. gas-free engineer engineer officer 2. engineer officer 4. B division leading petty officer 3. engineering division officer 4. NBC defence officer In items 1-23 through 1-27, select thedivision 1-18 Which of the following are duties of the of the shipboard engineering departmentfrom engineering department training officer? column B that is responsible for the tuskgiven 1. Observing instructions given at drills, in column A. on watch, and on station 2. Supervising the preparation of train- A. Tasks B. Divisions ing materials 3. Routing information about available 1-23. Operating air com- 1. R division service schooling pressors 4. All of the above 1 2. A division 1-24. Preserving watertight 1-19. Which of the following responsibilities integrity 3. E division belongs to the'main propulsion assistant? 1. Preparing the Engineering Log and Bell Maintaining firefighting 4. M division Book equipment 2. Supervising the engineering department yeoman 1-26. Maintaining gyro- ''N\L Training ship's personnel' inemergency compasses repair work 4. Maintaining the ship's power and 1-27. Operating steam-driven lighting systems turbogenerators 1-20. The duty station of a Fireman assigned to the M division of a ship is probably 1-28. A fireman assigned to E divisionmay be located in one of the expected to work in which of the follow- 1. enginerooms , ing spaces? 2. firerooms 1. Main motor room 3. repair shops 2. IC room 4. auxiliary spaces' 3. Electric repair shop 4. Each of the above 1-21. Which of the following practices are best A for learning the locations of steam valves 1-29. Who is responsible for training personnOi 4 in a ship's fireroom? in nSnmedical defensive measufesagainst 1. Ask a petty officer from the B.-division NBC attack? to point out each valve on the ship's 1. Ship's training offi blueprint and then memorize these 2. Damage control s atant locations 3. Leading petty o' icer in A division 2. Trace all the steam1\nesfrom begin- 4. Leading DC petty officer ning to end with the aid of the ship's , ,J blueprints and.diagrams and then ask 1-30. Wech of thefollo ing are duties of the the engineer dfficer to point out each NBC defense office ? valve 1. 'Maintenance o' NBC defense equipment 3. Memorize the location of all the valves 2. Decontaminat on of personnel. and ship with the aid of the ship's blueprints 3. Transport on of NBC casualties and verify the information on your 4. All. of t e above first trip through the fireroom 4. Learn the location of a few valves at 1-31. If one of the voids in your ship isopened, a time with the aid of the ship's which of the following is the duty ofthe blueprints and diagrams and actually gas-free engineer to perform? trace steam lines from beginning to 1. Determine whether personnelmay safely end enter the void 2. Determine whether Wig safe for welding in the area 3. Do both i and 2 4. Ensure that each welder in thearea has a firewatch checking for explosivegases 3 211 1-32. As one of his duties, a division of cer 1-41. Hull Maintenance Techniciano perform which recommends changes to the allowance 0 his of the following duties? division. He makes his recommendation 1. Plan, supervise, and perform tasks directly to the necessary fqx!abrication, installa- 1. commanding officer tion, and repair of allatypes of 2. department head structures 4) 3. division's technical assistant 2. Perform tasks relating to shipboard 4. department admin strative assistant damn fp control, CBR defense, and firefight ng 1-33. Aboirrd a large steam - driven ship, the oil 3. Supervis and train personnel in king supervises the op ration of mainte nce, hull repair, CBR defense, ' 1. small boats and damage control 2. motion picture projeaCtors 4. All of the above 3. transfer and booster umps 4. steam turbines Learning Objectives Recognize the 1-34. Small boat engineers are usually of what basic principles of physics that ratings? apply to shipboard machinery and 1. FN,EN,or IC equipment to produce work. Textbook 2. HT,EN,or FN pages 17 through 21. 3. FN,EN,or MM, L 4 4. EN,FN,or MR 1-35. It is desirable that a Fireman striking ' 1-42. Matter can be defrined as anything that for an engineering rating (Group VII) have occupies space nd has definite a knowledge of which of the following? 1. shape 1. Mathematics 2. volume 2. Physics 3. weight 3. Mechanical drawing 4. visibility 4. All of the above I 1-43. What is meant by the inertia of a stationary object? Ih items 1-36 through 1-38, select from column B 1. 'Quantity of matter which the object the rating of personnel who perform the tasks in contains yolumn A. 2. Force with which the object is pulled toward the center of the earth A. Tasks B. Rating. 'PhysicalPhysical property that keeps the object '&t rest 1-36. Pour castings of 1. Molder - 4. Measurement of the mass and the weight ferrous metals of an object' 2. Boilermaker -'91 -37. Operate millir 1-44. An object moving at a constant velocity machines 3. Machinery Repairman will eontinue moving at the same speed in the same direction until acted upon 1-38. Repair boiler 4. Machinist's Mate by some outside force. i equipment 4 1-45. Which of the following definitions describes the force that is exerted '1-39. The main propulsion turbines are main-. on a stationary object? tained by what rating? 1. A push or pull with which you cause 1. Boiler Technician c or try to cause an object to move 2. Machinist's Mate 2. A quantity that keeps the object at 3. Machinery Repairman rest 4. Engineman 3. A quantity of matter contained in the object 1-40. Whic of the following ratings has the 4. A physical property that causes a respo sibility for making repairs on the moving object to continue moving emerge cy generator diesel engines? 1. Machinist's Mate Machinery Repairman 3. Engin@man Electrician's Mate 21.2 1-46. Which of the following is a measure of . 1-55. Energy that exists because of tht$relative velocity? , velocities of two-oramore objects is called 1. 50 revolutions 1: potential energy 2. 50 rpm clockwise 2. kinetic energy 3. 50 rpm per }sec counterclockwise O 3. energy in transition 4. 50 rpm per sec clockwise 4. both energy in transition and potential energy Information for items 1-47 through 1-49: Assume that an object at rest was placed 1-56. Expended energy can be measured in work in motion and moved along a straight path. units of During the first 4 minutes of travel, the 1. horsepo 'velocity of the object was marked at 1-minute 2. specif heat intervals as shown by the following table: 3. Btu 4. foot-pounds Mark Velocity 0-minute 0 ft/sec In items 1-57 through 1-59, select the definition lrminute 5 ft/sec from columnB that best describes theterm in 2-minute 20 ft/sec column A. 3-minute 10 ft/sec 4-minute 15 ft/sec A. Term B. Defini4on 1-47. What was the average acceleation of the 441-57. gY 1. Applicatidn of force objeCt during the first minUte? through a distance 1. 0 ft per sec 1-58. Power 2. 2.5 ft per sec 2. Capacity for producing 3. 15 ft per sec 1-59. Work an effect 4. 20 ft per sec 3. 1-48. Amount of force per unit The object was decelerating between the area second and third minute marks. o o 4. Time rate of doing work 1,419. During the first 4 minutes, the object accelerated and decelerated at uniform rates. 1-60. How much work is done when a 60-pound box is raised from the ground to the top ofan 80-foot platform? In items 1-50 through 1-53, select fromcolumn B 1. 60 ft-lb the, source of the, type of energy in column A. 2. 140 ft-lb 3. 480 ft-lb A. Type of Energy B. Source 4. 4,800 ft-lb 1-50. Mechanical 1. Sun 1-61. A motor-driven hoist lifts a 165-pound load to a height of 50 feet in 30 seconds. 1-51. Electrical 2. Battery How much power does the motor develop? 1. 1/4 hp 1-52. Nuclear 3. Auto piston 2. 1/2 hp 3. 3 fip 1-53. Thermal 4. Reactor 4. 10 hp 0 1-62. What is the horsepower of a pump thatcan 1-54. Which of the following situations indi- lift 2,500 lb of water per minute froma cates potential energy? `depth of 66 feet? 1. Water striking a water wheel -1. 4 hp 2. Water behind a dam 2. 5 hp 3. Steam passing through a nozzle 3. 6 hp 4. Water being converted to steam 4. ,40 hp How much work can be done by,a 4-horsepower 1-65. A 5-gallon closed steel'tank is full of 1=63. a engine? water. `What happens to the pressut'e and 1. 2,200,000 foot-pounds of work per volume of the water in the tank when its minute- temperature rises? Z. 132,000 foot-pounds of work per 1. Pressure increases; volume remains constant minute . vs 3. 22,000 foot-pounds of work per minute 2. Pressure decreases; volume increases 04. 142,000 foot-pounds of work per hour 3. Hoek pressure and volume remain the same 1 -64. According tiCbarleslaw, if the tem- 4. Prepsure decreases; volume remains the perature of Alexibfe container of air same were doubled,I' the volume of air would . 1. be reduced by one -half 2'4 be reduced to one quarter the original volume A 3. remain Constant'ut the pressure would double 4. be increased to &ice the original volume I 6 qa 214 "Assigitriieitt 2 / Engineering Fundamentals; Ship Propulsion;Basic Steam Cycle Textbook Assignment: Chapters 3, 4, and 5 > . If a barome r reads 28 inches of mercury, what is the lmospheric pressure in Learning Objective:. Recognize the pounds per square inch? basic principles of physics that 1. 0.986psi apply to shipboard machinery and 2. 13.72 psi equipment to produce work. Textb k .., 3. 14.70 psi nages 21 through 30. tp 16,68 psi 2-5. At sea level the pressu in a tire is 24 psi gage..The absolute pressure in 2-1. Compared with water, how heavy is the tire is approximately mercury? 1. 9 psi 1. One-fourteenth as heavy 2. 24 psi' 2. The same weight . 3. 33 psi 3. Fourteen times as heavy 4. 39 psi 4. Fifty times as heavy 2-6. The pressure of the air in a space at 2-2. The forces in a mercurial barometer sea level is 27 -In. of mercury. What is which balance each other are the the pressure reading of the vacuum gage? 1. forces exerted by the atmosphere 1. 3.0 in. of mercury and the weight of a column ofmercury 2. 12.3 in. of mercury 2. force exerted by steam under pres- 3. 27.0 in. of mercury re and the force exerted by the 4. 45..7 in. of mercury weight of a column of mercury 3. weight of a column of mercury plus 2-7C What is the absolute pressure ofa ;pace the force exerted by the air in the for which the vacuum gage reading is 20 tube above the mercury, and the in. of mercury? force exerted by the atmosphere 1. 10 in of mercury plus 14.7 psi 2. 20 in. of mercury. 4. weight of a column of mercury, and 3. 30 inof mercury the pressure of the vacuum above 4. 40 in. of mercury the mercury,plus the force exerted by the atmosphere 2-8. What is the approximate absolute pres- sure of a space in which the vacuum 2-3. At sea level tle.absolute pressure inan reading is 4 in. of mercury? air tank measures 31 inches of mercury. 1. 2.0 psi How much more or less than atmospheric 2. 4.0 psi pressure is the pressure in the air 3. 12.7 psi tank? 4. 16.7 psi 1. 1 inch less 2. 1 inch more 2-9. If a pressure gage must be located at a 3. 2 inches less point below ,the pipe of the pressure 4. 2 inches more line being measured, th," vading on the gage includes the I exerted by the weight of the 'iquid above the gage. 0 7 2 I 5 _J to. 2-10. PA Williams obtains a reading on a water 2-13. What is the relationship between A, the pressure gage of 18 psi.The gage is force applied to the small piston, and located 3 feet above the water pipe. B, the force exerted by the large piston? Williams calculates the actual pressure 1. Force B minus force A 10 lb of the water to be 2. Force B is 10 times force to 1. 16.7 psi 3. Force A plus force B o 10 lb 2. 18.0 psi 4. Force Ais 10 times force B 3. 18.4 psi, 4. 19.3.psi 2-14. The area of the small piston in a hydraulic ' pfess is 3 square inches and the area 91 the large piston is 75 square inches. If a.force of 50 pounds is applied to the small piston, the large piston will (neglecting frictiohal losses) exert a force of 1. 25lb 4, 2. 250lb 3." 725lb 4. 1,250lb 2-15. How is the water removed froM the main ballast tanks when a submerged submarine is surfacing? 1. Motor-driven pumps syphon off the water 2. The water is forced out with air 3. The water flows-out thrIgh the phits under the pull of gravity 4. Hydraulic pumps syphon off the water 1 Items 2-11 through 2,414'are related to 2-16. The heat produced in a nail which is 40 figure 1A. being.hammered into a piece of wood is energy caused by 2-11 If a certain fprce is applied to the 1. physical changes in the nail small piston, what are the relationships 2. the increased motion of the molecules' . between pressuies in various parts of in the nail the system? 3. chemical, changes in the nail t- 1. The pressure on the small piston is 4. the friction between the hammer and greater than the pressure on the the nailhead large piston 2. The pressure on the small cylinder 2-17. Heat is defined as the flow of thermal is the same as the pressuDE-Acting energy. against the small piston and is greater than the pressure in the 2-18. How many calories are there in 25 Britis large cylinder thermal units? 3. The pressure in the connecting tube 1. 25 is the same as the pressure in the 2. 252 small cylinder and is greater than 3. 2,520 the pressure in the large cylinder 4. 6,300 4. The pressure is the same on all parts of all surfacee-.that enclose the 2-19. In which of thsofollowi4 forms of matter liquid are themolecu!s closest together? 1. Steel 2-12. If the weight onk'the large piston just 2. Boiling water balances the weight on the small piston 3. Gas it follows that the 4. Chilled water 1,force per unit of area is the same on both pistons 2. weights onythe two pistons are equal 3. force on the large piston equals that on the small piston 4. pressure is greater below the small piston than it is below the large piston 21 0 8 4 2-20. A block of ice at 32° F is allowed . to 2-28. All of the following are products_ of melt into water at 32° F. The thermal combustion except energy needed to bring about this change 1. .sulphur dioxide of state is referred to as 2. carbon dioxide 1. internal heat 3. nitrogen 2. specific heat 4. oxygen 0 3. latent heat of fusion sensible heat 2-29. ,The com4eteness wit4(which fuer,oil burns in the cylinders of a dieeel engine 2-21. H much heat is required to change 10 lb depends on , of ce at 32° E to water at 50° F? 1. how well the fuel is mixed with air. 180 Btu 2. how much air is present in the \. Z. ,440 Btu cylinder 3. 1,620 Btu 3. how much timeime the fuel-aiy mixture 4. 16,200 Btu is allqwed to burn 4. all lie above factors '44 2-22. How much heat is required to change 10 lb of water at 82° F to steam at 212° F? 2-30. If water is placed in a closed container 1. 82 Btu and boiledLt,e steam, will be saturated, 2. 130 Btu when the 3. 1,300 Btu .1. pressure in the container increases 4. 11,000.0tu '2. temperature of the water rises above 212° F 2-23. When ice is changed tolisteam, the greatest 3. temperature of the steam risk above amount of heat is required for 212° F 1.- changing the ice at 32° F to waterat 4. 32° F water changes Completely to steam at the temperature of boiling water 2. heating the water from 32° F to 150° F.. 3. heating the water from 150° F to 2-31. At 1 pressure of 110 psi absolute, water 212' F boils at 335° F. What is the actual 4. changing the water at 212° F to steam temperature of superheated steam at at 212' F 110 psi absolute when it has 200° F of superheat? 2-24. The amount o heat released by steam when 1. 310° F it changes in water at the same 2. 412° F temperature is c led 3. 535° F 1. sensible heat 4. 665° F 2. latent heat of condensation 3. latent heat of vaporization 2-32. If you hammer a sheet of copper intgithe 4. latent heat Of fusion shape of a hollow bowl, you are taking advantage of what property of the metal? 0 V-25. A reading of 75' C is equivalent to 1. Strength " 1. 160° F 2. Malleability 2. 163° F 3. Hardness 3. 167° F 4. Toughness 4. 170° F 2-33. What property of a metal permit it to 2-26 A reading of 77° F is equivalent to be shaped into wire form or sheets? 1. 23' C 1. Strength 2. 25° C 2. Ductility 3. 27° C 3. Hardness 4. 29° C 4. Toughness 2 -27. A Fahrenheit thermometer and a Celsius 2-34, All of the following are ways to reduce thermometer are placed into water that corrosion to steel except 7 contains melting ice. What are the 1. adding nickel or chromium pr both Towest possible temperature readings to 2. chogaing a better grade of base metal be expected? 3. pa4Sting the surface with a good 1. 0° on Celsius and 32° on Fahrenheit grade of_paint. 2. 0° on Celsius and0° onFahrenheit 4! coating the surface with ir.;<[ofide 3. 32° on Celsius and 0° on Fahrenheit 4. 32° on Celsius and 32° on Fahrenheit ? 0 2-35. You can determine whether a metal is 2-41: The strut, stern. tube, and line sha ferrous or nonferrous by using a magnet bearings funceion to support the m because most metals containingc iron are shaft and keep it aligned. magnetic. What technique is used in marking a steel bar according to the continuous Identifi- Learning,Ohjective: Identify the cation marking system? various'types of propulsion units. 1. A continuous strip of specified4Lidth Textbook pages 4 through 36. is painted along the entire length 15W of the bar Po F 2. The appropriate marking is painted on with heavy ink at specified intervals One f, the main differencekibetwe -a along the bar's length tur oelectric drive and a Para urbine 3. The appropriatsjiarking is punched on dri e is that the former uses with a metal Olfter at specified '1. a46maller Vatio.toreduce.turbine intervals along the bar's length speed to propeller)! speed AL 4. The appropriate symbol of specified 2., a laraer'ratio to q.Uuce turbine color is painted on each end of the speed to propeller speed bar 3. a cruising turbine to reduce turbine speed' to propeller speed 4. an electrical means instead of a turbine element to reverse propeller Learning Objective: Recognize the shaft rotation 0- basic principles of ship propulsion. Textbook pages 31 through 33. 2-43." By which of the foilowing is the speed. of a diesel d=c electric-driyen increased? t' L ""%e:101KI, 1. Increasing generator'vortage 2-37: What type of force (thrust) is developed 2. Increasing,engine speed. against the velocity imparting devices 3. Combining changes inagenerator shipboard) and causes the ship to move voltage and engine si$011 thrbugh the water? 4. Any of the above ,' 1. Acceleration 2. Inertia 2-44. In diesel d-c electric-diiven ships the ,4 3. Reaction direction of rotation of the propeller 4. "TorqUe is reversed by 1.' using reverse.gears In answering ithms 2-38 through 2-41, 2. reversing the flow of current through refer to. figure 4-1 of your textrok. the motor 3. reversing the direction of rotation 2-38. The thrust on the propeller is transmitted of the diesel engine to the ship by means of the 4:reversing the pitch of the propeller 1. strut blades 2. main shaft 3. high - pressure turbine 2-45. Advantage(s) of the diesel engine over 4. math reduction gear. the gasoline engine as the prime mover of a propulsion...unit for a naval vessel 1 2-39.fThe prime mover of the ship's propulsion include unit shown 1.1.1 the figure consists of a 1. less dan er:of fire " 1. geared turbine 2. cheaper fuel 2. diesel engine 3:1--standardiz4 fuels 3. generator and turbine 4. all of the above ter generator and diesel engine 2-40. The reactive force along the axis of the main shaft is absorbed by the 1.'.slrut bearing 2. stern tube bearing 3. line shaft bearings 4 thrust bearing.,- 10 21.8 2-52. Which of the following statement°Obout clutcheo io faloe? Learning Objective: Identify reduction 1.. Friction clutcheo con be cl000ificd gears and clutch°, used to convert power as diok or band and wet or dry to drive. Textbook paqs 38 through 2. Simple friction clutcheo may be used 47. alone in engine° with power ratings ao high ao 2,000 hp .. . 3. Wear occuro on a wet clutch during 2-46. By what means are low propeller-shaft engagement, dioengagement, and . speedo obtained in ship° driven by high- operation .speed diesel, engines? 4. Coot iron ourfaceo are good for 1. Clutcheo friction clutches becauce they 2. Reverse gears reoiot ocoring and ocuffing 3. Reduction gears .4. Pitch-changing devices 2-53. What type of clutch in uoed in the clutch aoaembly of the Gray Marina tranomiooion 2-47. How are the opeeds of turbineo and pro- mechaniom2, pellers related when a proputsion plant 1. Dry-type, single-diok io operating at maximum efficiency? 2. Dry-typo, twin -diok 1. Turbines are operating At high speeds; 3. Wet-type, single-diok propellers at low speeds 4. Wet-type, twin-dick' . . Propellers are -operating at high speeds; turbines at low speeds 2-54. An astern operation of the ohaft and. 3 Both turbines and propellers are propeller driven by the Gray Marine operating at high speeds engine is'accompliohed by 4. Both propellers and turbines fire 1. . reveroing the crankshaft rotation operating at low speeds 2. using separate dicks and gear train 3. reversing the forward disk rotation 2-48. End thrust imparted to b shaft by, reduc- 4. reversing the bock plate ticin gearing can be eliminated through the use of 2 -5. With Joe's clutch a d reversegeavothe 1. single-helical gears crankshaft rotationo transmitted Co 2. A do4ble-helical geais the redUction gear ohaft through the 3. spur gears . 1. crankshaft driV'e gear extenoipn 4. worm wheels 2. first reduction gear 3. locked train gearing 2-49. That isvpical about a double reduction 4. clutch and reverse gear unit propulsi gear arrangement? 1. Each double helical gear used does 2-56. What happens when compressed air (100 psi) the work of tt single- helical gears is admitted into the flexible tire ofan . Turbine speed is twice propeller airflex clutch while it rotates at,engine speed spe0.? 3. The rpm pro&ced by the turbine is 1. The clutch moves out'of contact with reduced in YWo steps the engine flywheel' 4. Its efficiency is doUble that oL s 2. The clutch make:I-contact with the single-teduction gear engine flywheel, 3. Friction blocks on the inner tired 2-50. Most diesel-driven ships and boats are surface make,contact with a clutch- backe&down by reversing the drum 1. pitch of the propeller 4. Friction bloCka on the inner tire 2. direction of rotation of the propeller surface move out of contact witha ohaft clutch drum 3. position of the engine relative to the propeller shaft 2 -57' What is one of the adyentageo of fluid 4. rotation of the engine crankshaft drives over mechanicgl clutches? 1. /lippage is completely eliminated 2-51. Regardless of type or aize'df inatalla- 2. No mechanical connection is needed non, the arrangements of clutch, reverse' between the engine and the reduction gear, and reduction gear are the same. gear) 3. Power loss is only 1 percent 4. Driving fluid doeb not absorb power loss 11 " 2-58. What function io served by the dog clutch 2-62. Suppose you boil the water in two when it in used in addition to the containero, A and B. A io an open friction clutch? container and exposed to atmospheric 1. Engagingait juot before engagingthe/ pressure, whereas B io a cloned container friction clutch speedo up the action in which the pressure io greater than of the friction clutch the atmosphere. What in the,relationohip 2. Engaging it after the friction clutch 4. between the temperatures of the water has equalized the speed of the two boiling in the containern? nhafts prevents slipping and mini- 1. The water tempeuture in A is higher sizes wear of the' rictionoclutch than that in D 3. Engaging it at the same time the 2. The water temperature in A in lower friction clutch in,engaged provides than that fn D for smoother transfer from one speed 3. The water temperature in A in 212° y, to another which in the same an that in 13\ 4. Engaging it during and after engaging 4. The water temperature in A in 212° F. the friction clutch helps to quicken which in greater than that in the change from one speed to another and makes for greater smoothness of 2-63. What in the purpone(n) of the nuaerheater operation furnace shown in the textbook fiihre 5-2? 02-59. The reaction forcedeveloped by the force 1. Raise the temperature of the maturated of the water being moved astern by a steam propeller acts on what part of the pro- 2. Draw the saturated steam from the peller? generating furnace 1. The back 3. Raise the temperature of the feed 2. The leading edge water without increasing prennure S3. me root 4. Do each of the above 4. The face 2-64. For which of the following reasons are 2-60. Which of the following statements with naval boilers designed to produce both regard to propellers in true? saturated and superheated steam? 1. Direction of propeller thrust can 1. Because superheated steam for propul- be changed on.some propellers by sion in more efficient than saturated changing the pitch of the blades steam 2. The number of blades on ship propellers 2. Because most auxiliary machinery varies ',from two to four operaten on saturated steam 3. Co., roll7lable pitch propellers are of 3. Both 1 and 2 above the Mingle casting type 4. Because propulsion and auxiliary 4. Left-hand helical propellers, as machinery operate on saturated and viewe4 from astern, trn clockwise superheated steam and frequently to mov41 the ship forward switch from the use of one to the use of the other 2-65. What energy conversion takCs place after Learning Objective: Recognize the steam enters the turbine of a oteam- (our areas ation of the basic driven ship? steam cycles. Text ook Pages 49 1, Heat energy to electrical energy through 53. 2. Mechanical energy to heat energy 3. Heat energy to mechanical energy 4. Electrical energy to heat energy 2-61. The amouni.of latent heat required to" change boiling water to steam is the same 2-66. If your ship's main turbin stallation regardless of the pressure in the gener- is like that shown in text k figure 5-1, steam from the boilete4o expanded ating container. . tt, in the 1. cruising turbine 2. hl,gh- pressure turbine 3. slow- pressure turbine 4. cruising, high-pressure, and low- pressure turbines 220 . Porgy itemo 2-67 through 2-70, refer to 2-/1. The diccharge preasure of a main feed figure 5-1 in your textbook. pup diacharging to a boiler operettas at 600 poi lo approximately 2-67. In which port of the oteam cycle Jo air 1. 55C poi removed from the condenoato? 2. 700 poi 1. A 3. 750 poi 2. 4. 1,000 poi 3. C 4. D 2-72. Watpr io preheated in the oconotiter by 1. heating it with a ouperhooter located 2-68. The dotted linoo onelooing C and D Dhow directly under tho economizer that tho deaerating tank belongs to which 2. circulating it in tubeo ourrounded 'part° of the otoam cycle? by tho got= of combuotion 1. Generation and feed 3. mixing it with jeto of hot air that 2. Feed and condenoato are pumped into the economizer ,3. Expanoion and generation 4. mixing it with hot water dioeharged Condenoato and expanoion from the main feed piping oyotem 2-69. The deaerating tank in the oteam cycle 2-73. The main difference between the auxiliary io uoed for which of the Allowing oteam cycle and the main nee= cycle io purpooeo? that the auxiliary doco NOT include the 1. To remor any trapped oxygen or air 1. condenoer from the condenoate 2. &lactating feed tank 2. To preheat the water before it g000. 3. ouperheater to the economizer 4. economizer' 3. To verve ao a otorage tank for reocrve feed water and for ourpluo -condenooto 4. All the obovo 2-70. The condenoato from part C of the otoom cycle firot become° feed water in the 1. economizer 2. top section of the deaerating tank 3. otorago ()action of the deaerating tank 4. piping between the main and b000tor . feed pump() El .221 13 7 Assignment 3 3Boiler°, Steam Turbine° and Reduction Gear° Textbook Aseigntent: Chapter°, 6 and 7 3-6. Refractory material is uoed to line the z °teal caning ofdboiler furnace in order Learning Objective: Identify major to component° of naval boiler° and 1. prevent excepoive loaaeo of furnace state their functions. Textbook heat page° 56 through 71. 2. help maintotAn high furnace temperatures. 3._ protect the caning from the intense heat in the furnace 4. do all of the above 3-1. The °teem drum of a boiler aerve° as all of the following except a 3-7. What boiler component utilize° heat from 1. reaervgir for the ateam generated in combuotion gat= to heat incoming feed the tube° water? 2. °operator of moiature from the °team 1: Air preheater %generated in the tube° _2. Economizer 3. .'otorage apace for boiler water which 3. Deaerating feed-heater is diatributed to downcomera 4. Header 4. separator of air from the °team generated in the tube° 3-8. Finn on economizer tube° nerve to 1. decrease the right of the tube° 3-2. Which part° of a boiler function to 2. absorb the heat from combuotion gage° 'Pk distribute water equally to the generating 3. speed the flow of combuotion genes tubea?' 4. increase the capacity of the tubes to 1. Steam drum and economizer hold steam 2. Downcomera and economizer 3. Water drum and sidewall hedder 3-9. Each end of a horizontal superheater tube 4. Sidewall tutie° and aidewell header is connected to a 1. vertical superheater header 3-3. The generator tubes in a boiler are 1 to 2. horizontal superheater header 2 inches in diameter instead of 3 to 4 3. vertical sidewall header inches becauao smaller tube° absorb more 4. horizontal aidewell header hjat from the hot gape° circulating around them. 3 -10. What type of atomizer is Most common and uoed on most older °hips? 3-4. In addition to d&recting the flow of steam 1. Return -flow 4 from the eidewell header to the °team drum, 2. Straight-steam the tidewell generating tubes nerve to 3. Steam- ssiat 1. direct the flow of water from the 4. Str ght-through-flow °team drum to the aidewell header 2. protect the sidewall from the intense 3-11. Which part or parta,of an air regioter in heat in the furnace a burner assembly impart a whirling motion 3. dietribute water equally to the down- to inrualling air? camera 1. Air doors 4. direct the flow of combuotion gases 2. Diffuner plate around the economizer tubes 3. Air foila 4. Air doors and diffuser plate 3-5. Downcomers are uced to direct the flow of ,water from the steam drum into, the 1. economizer 2. water drum 3. aidewell header 4. water drum and sidewall header 222 SO 3 -] v....1)08e of the tangential oloto in a 3-19 The baoic typed of auxiliary boilero used oprayer plate are to by the Navy include 1. form the cone ohaped spray . 1. fire-tube boilero 2. break up the.oil into fine particles 2. water-tube natural circulation 3. impart a rotational velocity to boilero the oil 3. water-tube forced circulati9n boilero 4. mix the fuel with air 4, all of the above 3-13. Fire-tube boilers have been replacedby 3-20 Boilers operating at 700 poi burn leoo water-,tube boilero on most naval ships fuel for a given shaft horsepower than do because boilero that operate at lower preooureo. 1. fire-tube boilers have a higher concentration of scale-forming salts 3-21. When working in"a fireroom aboard ohip) than water-tube boilers you should keep your shirtmleeveo rolled 2. fire-tube boilers are more difficult down at all times. to examine than water-tube boilero 3. fire-tube boiltrs are not able to 3-22. Before lighting off a boiler you should meet the demand for rapid changes in remove some of the water from the econo- load that water-tube boilers can mizer by using the emergency feed pump. 4. fire-tube boilers have more compli- 0 cated construction than water-tube 3-23. You are preparing to puta boiler into boilers operation. Before lighting off the firot saturated burneryou should be oure to 3-14. The circulation of water in natural circu- I blow down the gage glasses lation boilers depends on the difference purge the furnace between the density of rising steam-free leave disconnected atomizers in place water and the density of falling hot.water 4. remove the atomizers from the regiotero and oteam. 3-24. Which of the following safety precautiono 3-15. "Water is made to run faster in accelerated applies to the securing of a boiler? natural circulation boilers than in free 1. Closing_the openings to the furnace as natural circulation boilers by soon as the atomizers have been put 1. wider nozzles of generating water out tubes 2. Bringing the water level in the gage 2. tubes connecting steam drum to water glass to the point where it shows drum sloping at a steeper angle three-fourths full 3. application of more heat 3. Closing the master oil valve"after the 4. an increased number of downcomers S fuel oil pump is secured A. Each of the above 3-16. Where are downcomers installed on accel.- erated natural circulation boilers? 1. In the furnace area 2. Between the steam drum and water Learning Objective: Recognize the drums outside the furnace principles of operation of naval steam 3. Between the sidewall tubes and inner turbines and identify major components casing and their functions. Textbook pages 4. Between the economizer and the super- 72 through 81. heater 3-17. The superheater tubes in convection-type 3-25. In addition,, to direction of steam flow, ' superheaters are protected from the in which way may turbine types be classi- radiant heat'of the furnace by fied? 1. ,baffles 1. The way in which the steam makes the 2. water screen tubes turbine rotor rotate 3. downcomers 2. Type of staging and compounding of 4. generating tubes steam pressure and velocity 3. Division of steam flow 3-18. The steam from a pressure-fired boiler 4. All of the aboy ways installed on a 1040-class destroyer escort is used exclusively for 1. propelling the ship 2. distilling sea water 3. heating the crew's berthing spaces 4. laundering 15 2 2a 3-31. The function of the otationary bladed in a velocity-compOunded impuloe turbine io to 1. increase the velocity of oteam 2. direct the flow of oteam 3. decrease the velocity of oteam 4. increase oteam pressure without loss in velocity 3-32. The efficiency of a single -stage impabla turbine is increased by adding 1. rows of moving blades to the rotor wheel 2. simple impulse stages in the oame Figure 3A.-Diagram of Hero's engine. casing 3. either 1 or 2 above 4. rows of fixed blades to the casing 3-26. In figure 3A, the steam escaping from the nozzles causes the engine to 3-33 A reaction turbine is driven by the 1. remain stationary reaction of the force required to 2. turn clockwise around point X increase the velocity of steam as'it 3. turn counterclockwise around point X passes through the nozzles. 4. turn alternately clockwise and counterclockwise around point X 3-34 The length of the blades of a reaction- type turbine is increased at each succeed- 3-27. Which of the following devices operates ing stage in order to accommodate the most nearly according to the impulse 1. higher turbine speeds turbine principle? 2. steam condensate 1. Hero's 3. increased steam pressure 2. An elect ic fan 4. increased volume of,the steam 3. A windmill 4. A jet pump 3-33. What happensto the steam that passes . through eachstag& of-a reaction turbine? 3-28. What happens to the ste4 that passes 1. It gainspressure and loses velocity. through the steam nozzles of an impulse 2. It gainspressure and velocity turbine? 3. It losespressure and velocity 1. Itloses pressure andgains velocity 4. It losespt4ssure and gains velocity 2. Itlosespressure andloses velocity 3. Itgainspressure andloses velocity 3-36. To permit a turbine to expand and contract 4. Itgainspressure andgains velocity on its foundation, the turbine is usually installed by securing its 3-29. What happens to the energy in pressurized 1. forward end rigidly and allowing some steam as it emerges from the nozzles of freedom of movement to the after end an impulse turbine? 2. forward and after ends in separate 1. Kinetic energy converts to potential grooves Olowing each end to move energy independently 2. Potential energy converts to kinetic 3. forward and after ends to a sliding energy sunken plate 3. Kinetic energy converts to thermal 4. after end rigidly and allowing some energy freedom of movement to the forward 4. Potential energy converts to mechanical end a energy 3-37. Which of the folowing metals is used in 3-30. How are the blades arranged in a velocity- the making of turbine casings and rotors compounded impulse turbine? to enable them to withstand the effects 1. Two or more rows of revolving blades of superheated 700° F steam? are followed by a like number of rows 1. Carbon steel of stationary jets 2. Carbon molybdenum steel 2. One row of stationary blades follows 3. Cast irorf. each two rows of revolving blades 4. Bronze 3. Revolving and stationary blades are installed in alternate rows 4. Both revolving and stationary blades are provided on each row 16 224/ 3-38: Which bearings aro used in 'a propulsion turbine to carry the weight of the rotor and to maintain the proper radial clear- Learning Objective: Recognize the ance between the rotor and the caoiig? common form of reduction gears used I. Ball or roller bearings in shipboard machinery. Textbook pages . 2. Spherical - seated sleeve bearings 81 through 83. 3. Cylindrical sleeve bearings - 4. Spherical-seated or cylindrical sleeve bearings 3-44. Which type of double reduction gearing 3-39. Propeller thrust bearings and turbine (if any) do moot auxiliary ships use thrust bearings differ chiefly in for main propulsion? 1. design 1. Nested 2. size 2. Articulated 3. materials from which they are made 3. Locked train 4. function 4. None 3-40. A function of the turbine rotor-shaft 3-45. Wiat type of metal is used for the teeth glands is to prevent in the,ptnion gears of the main reduction 1. lubricating ail from leaking into gears? the turbine casing 1. Bronze 2. lubricating oil from leaking into 2. Cast steel the engineroom 3. Forged steel , 3. steam from leaking out of the turbine 4. Copper-nickel casing 4. any of the above from happening 3-46. Bull gears are usually secured to their shafts by means of 3-41. When carbon and Labyrinth packing are 1. spot welds ssv used in one turbine rotor-shaft gland, 2. keyo how are they arranged? 3. locking nuts 1. Carbon packing is us in the high- 4. keys and locking nuts pressufe area and yrinth infthe low-pressure are. 3-47. The base section of a bull gear casing is 2. Labyrinth packing is used in the used for several purposes, one of which high-pressure area and carbon packing is to support the is used in the low-pressure area 1. main thrust bearing 3. Carbon and labyrinth packing are 2. bearing housing for the intermediate used interchangeably pinions 4. When temperatures are to go over 3. bearing housing for the intermediate 650° F, only labyrinth packing is gears used 4. bearing housing for the high ope pinions 3-42. By what means are low pressure turbine glands sealed at all times to keep air 3-48. Which gears are used in transmittin from entering the condenser? motion from a turbine to the shaft 9f a .1. By passing auxiliary exhaust steam condensate pump and in reducing turbine to the glands speed to pump speed? 2. By increasing the pressure inside the 1. Pinion and single helical gear steam chest 2. Two bevel gears 3. By decreasing the temperature inside 3. Worm and worm wheel . the steam chest 4. Pinion and double helicargear 4. By lubricating the glands will low- viscosity oil -, 3-43. In low pressure turbines, and gland seal- ing steam pressure is maintained at approximately 1. 0 to 1 psi 2. 1/2 to 2 psi 3. 2 to 3 psi 4. 1/2 to 4 psi 17 225 3 -53. Which of the folloqing valve° io uacd to prevent excessive piteobure in.thecd1 Learning Objective: Recognize the feed lines of a lube oil pump protem? characteristics and purposes of 1. Governor lubricating oils and greases used 2. Throttlg in the Nally. Textbook pages 84 through 3. Reducing 87. 4. Relief 3-54. How do you regulate the temperat r 3-49. Which of the following 1.8 the beat the oil flowing around the tubes o_.,a definition of friction? A tube-in-shell type of oil cooler? 1. Friction is the amount of pre:inure, 1. By regulating the amount of oil flow- with which one surface is pressed ing around the tubes against another surface 2. By regulating the amount of sea water 2. Friction is the amount of heat flowing through the bes generated between two sliding 3. By doing both of t e a..ve surfaces 4. By regulating the 3. Friction is the resistance that one circulating around surface offers to its movement over another surface 3-55. 'ssume that you notice n su en; decided 4. Friction is the ratio of the rough- drop in the pressure gage in the oil feed ness of one surface to the roughness line to the turbine bearings. The Chief of another surface Machinist's Mate will immediately order you to 0 3-50. Under ideal conditions, what kind of 1. slow down the engine until cressure friction occurs when a main shaft rotates builds- up.again in a properly oiled main journal? 2. stop the engine 1. Fluid friction between the molecules 3. deCiease the pressure in the co ,ling of the oil and.the suspended foreign , tubes matter in the oil 4. increase the pressure in the cooling 2. Fluid friction between. the molecules tubes of the oil and between the film of oil on the shaft and the film on 3-56. Mineral lubricating oils can withstand the journal the effects of high temperatures and 3. Sliding friction between the main 'speeds better than either animal or shaft and the main journal Vegetable oil. 4. Rolling friction between the main shaft and the main journal 3-57. Assume that 60 clof a class 3 oil at a, temperature of 130° F require 3 minutes 3-51. If the correct lubricating oil is replaced to pass through the Saybolt viscosimeter. by an oil of a higher viscosity, a bear- Which of the following symbol numbers ing will be subject to .,would be used to designate the oil? 1. increase in pressure and in operating 1. 1300 temperature 2. 1803 2. increase in friction and in operating 3. 3003 temperature 4. 3180 3. decrease in friction but increase in operating temperature 3-58. Why does a,,2190TEP oil provide reduction 4'4. increase in friction but decrease in gears more protection than a 2190 oil? operating temperature 1. It resists corrosion better 2. It protects better against the effects , 3-52. Whefe are Zerk fittings used? of water 1. On rotary water pumps 3. It can withstand heavier loads 2. On turbine bearings 4. It does all of the above 3. On lube oil pumps 4. On bearings with a heavy load 3-59. What type of grease is used as a general purpose grease for light loads and ordi- nary operating temperatures? 1. Graphite grease 2. Soda soap grease 1. Lime soap grease 4. Lead oleate soap grease 18 226 3-60. Which of the following lubricating greasier) 3-62. If a lubricating chart has not been Mode contains a (menial additive to prevent up for a certain unit of machinery Aboard meting at high temperatpren? ship, you should determine the type of 1. Lead oleate grease lube oil opecified lor the unit by con- 2. Extreme prenoure greaoe ealting the manuface4pr's technical 3. Graphite grease manual. 4. Oxidation inhibitor greaoe 3-61. Hard grades of greaoe are used for lubri- cation of part° used at 1. high opeedo under light pressure 2. medium opeedo under medium pressure 3. plow speeds under hpavy pressure 4. high opeedo under heavy pressure . 19 227 Assignment 4 Auxiliary Machinery and Instruments, Pumps, Valves, and Piping Textbook Assignment: Chapters 8, 9, and 10 4-5. How is fresh water obtained from the vertical basket type of steam-operated Learning Objective: Identify the distilling plant? location and functions of shipboard 1. By vaporizing preheated feed water auxiliary machinery and equipment. over and over again and,then condens- Textbook pages 89 through 99. ing the feed water vapdr 2. By using steam to boil sea water and then condensing the fresh water vapor 0- 4 given off by the boiling sea water 4-1. ThS vapor compression refrigeration-system 3. By using combustion gases from a is used on naval ships for which of the boiler furnace to boil feed water in following applications?, a coil and then condensing the fresh 1: Refrigerated cargo water vapor glen off by the boiling' 2. Refrigerated ship's stores feed water 3. Ship's service store equipment 4. By using combustion gases froin a 4. All of the above boiler furnace to boil sea water in a' coil and then condensing the fresh 4-2. For Navy ships designed after 1950, the water vapor given off by the boiling freeze room and chill,rts are kept at seawater which of the following te peratures? 1. 0° F and 33° F, respectively 4-6. When there are two soloshell double-effect 2. -5° F and 20° F, respectively evaporator plants aboard a destroyer, 3. -10° F and 10° F, respectively they are located in the aft engineroom. 4. -20° F and 5° F, respectively 4 -7 The two types of steering gear used by 4-3. The purpose of air. aboard the Navy are electromechanical and naval ships is to electrohydraulic. 1. provide comfort for the crew 1 2. protect equipment from high tempera- . 4-8 In which of the following respects is tures electrohydraulic steering gear superior ' 3. increase personnel efficiency to electromechanical steering gear? 4. do all of the above 1. Depend it and flexibility 2. Saving' In weight and space occupied 4-4.'In the vapor compression distilling plant, 3. Less friction between moving parts the source of energy used t heat sea and quicker responses to movements of water is the steering wheel 1. steam 4. All of the above respects 2. boiling water 3. electricity 4T9. To meet Navy requirements, an anchor 4. furnace gases windlase must be equipped with brakes and 'a means of reversing direction. 4-10. The capstan shown in textbook figure 8-7 is used for 1. heaving-in on anchor chain 2. paying-out on anchor chain 3. heaving-in on heavy mooring lines 4. lifting boats ) 228 20 4. P 4-11. The three wings on the tubular-type of oil purifier serve to lekeep the oil rotating at the speed Learning Objective:Recognize the of,the,bowl A principles of operation and uses of 2. collect the sediment or other impuri- engineering measuring instruments. ties Textbook pilges 100 through 115. 3. separate the oil into three layers 4 4. help accelerate the rotation of the bowl t4-18. The gages and other measuring instruments 4-12. Aboard Navy ships, compressed air is used in a shipboard engineering plant enable fob operating personnel to X. charging and firing torpedos 1. determine operating efficienOy of, 2. starting diesel engines )heplant 3. operating pneumatic tools ' 2. bbtain data for records and reports 4. all of the above 3. detect abnormal operating conditions in a system 4-13. Which type of air compressor is used most 4. go all the above in the Navy? 1. Centrifugal, turbine-drive 2. Reciprocating, electric-drive 3. Rotary, diesel-drive In items 4-19 through 4-4, select the type of 4. Rotary, electric-drive measuring instrument from column B that provides the kind' measurement in column A 4-14. Medium pressure air compressors are those with discharge pressures that range A. Measurements B. Instruments between -* 1. 51 and 100 psi 4-19. Height in inches 1. Pressure gages 2. 101 and 150 psi 3. 151 and 1,000 psi 4-20. Turns per minute 2- Liquid level 4. 1,001 and 1,200 psi indicators 4-15. If pressure fails in the high-pr Abure 4-21. Total gallons 3. Revolution tank of a direct plunger lift elevator, counters what devices check the elevator's fall? 4 -22. Pounds per square 1. Mechanical locks inch 4. Fluid flow 2. Guide rails meters 3. Special control valves 4. Automatic quick closing valves in the oil line 4-23. On what principle does a Bowdon tube gage work? 4-16. The speed of the gypsy head of an electro- 1. Volume changes in a strght elastic hydraulic winch is controlled b7 tube tend to expand the tube 1. regulating the operating curtsnt of 2. Volume changes in a coi ed elastic its a-c motor tube tend to collapse t 2. regulating the operating voltage of 3. Pressdre in a straight elastic tube its a-c motor tends to bend the tube 3. adjusting the stroke of its hydraulic 4. Pressure in a curved elastic tube pump tends to straighten the tube 4z adjusting the clearance between the friction surfaces of its brake 4-24. The tube in a simplex Bourdon tube gage is connected to a pressure source and 4-17. The galley equipment aboard modern naval to an indicating mechanism. The ends ships include all of the following except of the tube are fastened to a 1. toasters 1. stationary base and a connecting link, 2. mixing machines respectively 3. extractors 2. stationary base and a connecting 4. refrigerators lever, respectively 3. connecting link and a connecting Aver, respectively 4. movement support and a gear sector, 229 respectively 21 / 4-25. ,,When the press a being measured with the 4 -32. The element of a bimetallic dial thermom-% gage shown irr,t ctbook figure 9-2 is eter responds to a rise in temperature increased, the Lnkage end of the Bourdon by tube has a tend icy to move so as to 1. expanding outward, thereby'leasing cause the against the wall of the retaining gear sector teeth to disengage from tube e pinion zar" 2. unwinding, thereby twisting the free 2. to bect ae more curved. end of the element 3. ter to tun cl 3. contracting lengthwise, thereby pull- 4, p er to tun c unterclockwise ing the free end of the element inward 4-26. Which the following measurements is 4. expanding lengthwise, thereby, push- taken w th a simplex Bourdon ttiBt gage? ing the free end of the elemdht 1. Depth of water in a ship's fresh outward water tanks 2. Amount of fuel oil flowing through a 4-33. Which component is the sensing element valve of a distant-reading mercury - filled 3. Pressure in a cOmpiessed air system thermometer? 4. Pressure drop between inlet and outlet 1. Mercury bulb sides of a lube oil strainer 2. Capillary tubing 3. Flexible cable 4-27. 'The duplex Bourdon tube gage .can be , 4. Bourdon-tube pressure gage thought of as two simplex gages in ong. However, the duplex gage ups a'single '4-34. Which of the following types of thermom- 1. gear mechanism eters indicates temperature change as 2. dial a result of pressure-volume changes? 3. pointer 1. Bimetallic 4. tube 2. liistant-reading 3. Liquid-in-glass 4-28. The type of gage whose.indicating mecha- 4. Pyrometers nism is shown in figure 9-6 of your ts` textbook is used for measuringkressures 4-35. The metals that makeup the actuatiriki that range between element of a pYrometar tespond to a 1. , 0 and 15 psi gage rise in temperature by converting heat 2. 16 and 30 psi gage energy into 3. 31 and 50 psi gage 1. chemical energy, 4. 51 and 100 psi gage 2. luminous energy » 3. electrical energy 4-29. Which type of instrument is best for 4. mechanical energy measuring air pressure in the space .. between the inner and outer casings of 36. In thestatic head gaging system, the a boiler? '..) amount of liquid in a tank is determined 1. Duplex Bourdon tube gate by means of a-direct measurement and ' 2. Compound Bourdon tube gage conversion to another unit of measure. t, 3. Bellows gage Which direct measurement and conversion 6 4. Diaphragm gage is used to determine the amount of oil in a fuel oil storage tank? 4 -30.' Which of the following parts is the 1. The depth of oil is measured directly essential element of a manometer? in feet and is converted to gallons 1. Bellows of oil' 2. Bimetallic strip 2. The pressure of the oil at the tank 3. Diaphragm-covered chamber bottom is measured in inches of 4. Liquid-filled U-tube -.. mercury and the pressure is converted to.gallons of oil . 4-31. Most liquid-in-glass thermometers -in 3. The temperature of the oil at the s pboard engineering plants are filled tank is measured, directly in degrees and the temperature is converted to 1. hyl alcohol gallons of oil 2. be ine 4. The volume is measured directly in 3. mercury cubic feet and volume is converted dyed water 7 to gallons of oil 22 230, FIRST READING SECOND READING Figure 4A.-4ound readingregisters. 4-37. The two meter readings of figure 4A were 4-41. Which of the followin& types of tachom- taken 1 hour apart.How much liquid was etersan be used to asure the speed measured during the hour? of a rotor when there is no access to 1. 699 gal its rotating shaft? 2. 869 gal 1. Centrifugal 3. 938 gal 2. Chronometric 4. 1,129 gal 3. Resonant 4. Any of the above 4-38. Which quantity is measured directly with icYrevolution counter? 4-42. Which type of tachometer is used to t Rotational speed of a turbine obtain speed readings continuously instead 2. Rate at which oil flows through a of intermittently? r pipe 1. Portable centrifugal 3. Total number of turns made by a shaft 2. Portable chronometric 4. Rotational speed of a pump 3. Revolution counter 4. Resonant reed tachometer 4-39. What instrument is commonly used to measure the rotational speed of a shaft? 4-43. The superheater temperature alarm on a 1. Manometer boiler is actuated by an electric micro- 2. Tachometer switch. The force that throws the 3, Hydrometer microswitch is provided by a Barometer 1. pressure that is exerted by a rise in temperature 4-40. Withhich kind of tachom f do you 2. cantilever arm that moves when mercury make direc't contact w a LacABg P expands in a spiralzwound Bourdon shaft to obtain instantaneoug vAITO tube of speed on a dial face? 3. revolving gear that meshes with the 1. Centrifugal microswitch 2. Chronometric 4. torque that is exerted when a bimetal- 3. Both 1 and 2 are correct lic element is heated - 4. Resonant 4-44. Which signal is an indication of low , pressure at the bearing located farthest from the lube oil, pump? 1. Steady red light on a control board 2. Ringing bell or loud siren 3. Intermittent buzzing sound 4. White light flashing on and off 23 231 e throttleman warned if he tries 4-51. In which, pump is the Movement of fluid . to open the ahead throttle valve when the due to a plunger that moves up and down engine ordef telegraph indicates "astern"? inside a cylinder? 1. By smoke coming deankfro;the pert., 1'. Rotary scope smoke indicator 2. Reciprocating 2. By a flashing light on the throttle- 3. Catrifugal board 4. Propeller 3. By a loud signal coming from the wrong direction alarm 4-52. Why, are reciprocating pumps used for 4. By a burting sound coming, from the emergency feed water pumps on naval static head gaging system Itg vessels? 1. They are easy to operate 2., The are reliable starters under cold conditions Learning Objective: Identify some 3. They can be started safely even by principles of pump operation and personnel having little experience specify the ways of classifying pumps, 4. Al) of the above reasons giving essential construction features of different components. Textbook pages 116 through 123. 4-46. What is the name for a device which is le to move a fly frem one place to any her through the use of an Tmernal po source to Apply a force to the flui 1. or 2. urbine 3. Pump . 4. Valve Figure O.-Double-acting pump. 4-47: Pumps supply the sea water in a ship's firemain system. ValvesAn the system 4-53. In the pump'shown in figure 4B, fluid is furnish the means of controlling'ihe discharged on the dowdAtroke'through directidh that .the sea water flows A ° 1. valve B 2. amount of seawater flowing 2. vafve D ".. 3. pressure of the set water Valvds B and D 4. direction of flaw, amount, and pres- 4. valves C and 'D 4 sure of "he sea' water 4-54, How do the valves move when piston P in 4-48. Which of the following pumps is classi-. the pump shqr in figure 4B moves upward? fled according to,the- type of movement, u 1. Valves A and C close; valves B and D that causes it to pump? open 1. Variable stroke pump 2. Valves A and D open; valves B and C 2. Positive displacement pump close 3. Self-priming pump I- Valves A and \p close; -valves B and C 4. Jet pump -open 4. Valves A aqd open; valves .0 and D\ 4-49. Which of the following pairs of words close refer to the same end of a pump? 1. Power end and fluid end 2. Liquid end and pump end 3. Power end and pump end .4. Pump end and Ateam'end 4-50. Aboard ship, you might refer to the power enl of a fireroom pump drivetkby an auxiliary turbine as the 1. rotorend 2.. turbine end 3. impulse end z r 4. steam -end b gV 24 '232 STEAM CHEST A Figure 4C.-Operating 8 principle of D-phaped slide valve of a reciprocatingpump. Figura 40.-Simplogoar pump. 4-55. The D-valve in the pump, figure 4Cis moved up and down 4-60. by the Aasame that thegear pump of figure 1. 4D...is pressure in the steamchest used for lubricating 2. oil service. Now piston rod througha mechanical does the oilpass through the pump? linkage 1. 011 moves intothe pump through 3. movement of exhaust steam through the suction side A,passes around the cylinder ports gears in,the spaces 4. between the pump difference inpressure betwejk the case and he gear teeth and upper, and lower discharges halves of thesteam through ditlet B chest 2. Oil moves into thepump through suction side A, ' passes through tE. 4-56. Aftei- first gears, and discharges two closing the throttlein the through out- process of securing let B aoreciprocating pump, the next step 3. you take is to Oil moves into thepump through 1. close the exhaust valve syction side B,passes around the 2. cloSe theralves in the discharge gears in the spacesbetween pump lines case and the gear teeth,an4 dis- 3. open the drain valveh charges through ft outlet A 4. 4. close the valvesin the suction line Oil moves intothe pump through suction side B, 4-57. passes thrpugh the The movement that two gears, and discharges causes a variable through stroke pump toactually pump and by outlet A the pump is classified which is brought about by 4-61. Positive displacement pumps include all 1. a tilting block rotating of the following inside a except cylinder 1. Screw 2. pistons reciprocating 2. Reciprocating 3. inside cylinders 3. propellers rotatinginside cylinders Centrifugal 4. 4. an impeller rotatinginside a casing Variable stroke 4-58. The of a aterbury stroke pum variable is determined bythey 1. size of the cylinder 2. tilt of the angleplate' 3. speed of themotor 4. direction of oil flow 4-59. Which condition'eiiiitswhen the tilting box is at right angles to the driveshaft while the pump isrotating? 1. The pistons reciprocate 2. Liquid is pumped 3. No liquid is pumped 4.. Power is transmitted hydraulically L 25 233 Assignment$ 5 Pumpo, .Valveo; Piing, and ShipboardElectrical Equipment TentbOok Apoignment: Chaptoro 10 and 11 ejectors or 5-6. Jet pumps are Clapp/fled ao eductorn deco dim to whethetooteam or voter io used to entrin and move fluido. Learning Objeative: Iden$,ify the location and functions of ohipboard . 'l auxiliary machinery and equipment. Textbook pagan 122 through 126. 5-1., The,,ocroc pump io similar tothe gear pump " in that both are 1. pooitive diopladement rotary pumpo E 2. variable capacity pumps 3. pooitive dioplacement centrifugal pumpo 4. non -self- priming pump° of a con- 5-2. Fluid entering the inlet pipe trifpgal pump in firot,directed intothe 1. center of the cooing, 2. ,vane o of the impeller and 3. opac6 between the impeller vaned ATMOSPHERIC , thd cooing PRESSURE 4. volute diffuoer in the 5-3. What precaution muot be taken inntallatipn of a centrifugal pump to enoure ffilt it Will become primed hen itslakepipeln open? above the 1. e intake pipe only in urface of the liquid to be pumped the our- 2. The intake pipe only in below face of the liquid to bepumped 3. The entire pump io abovethe'ourface of the liquid to be pumped The entire pump in below theSurface 4. Figure 5A of the liquid to be pumped Why in pumping action liquid in a 5-7. Refer tq'f/gure 5A. 5-4. A propeller pump pueheo m4ablid,heti after °team lower° the pren- direction perpendicular to theohaft. sure'in C by forcing fluid into E? Velocity increase at B drawnfluid makeo them 1. 5-5. Which feature of jet pump::: from A and diochargeo it through,B different from all Other pumpoclaonified causing 2. Pressure difference between cand acqording to the type of movement atmoopheee lifts fluid /Tao C and 'the pumping action? through A 1. HigH auction lift 3. PresstA difference between C and the 2. No moving parts atmosphere lifts fluid into Cand 3. Self priming through E 4. Positive displacement 44Velocity increase at B draws fl from A and discharges itthrou 26 23 i 5-0. On new combatant nhipo, the primary meann 5-14. What tattoo place inolde /cho body of a of dewatoring comparCmontn through the plug wave when tho handle io turned to drainage ayatem are open tho valvo? 1. fire and blip pump° 1. A dick lift° oft its °eating ourface 2. fixed-type cOuctor° 2. A ball-ohaped piece float° off a 3. centrifugal tiro pumpa owning ring 4. Watorbury variable-volume pump° , 3. 4 poo0Ogovay in an othorwioo solid piece linen up with the porto in the 5-9. If a conotant-pronouro pump governor in valve body attached to a gear pump, the governor in 4. A wedgo-ohaped piece ri000 to create connected to-the an opening in the parmageway through 1. driving gear the valve body 2. driven guar 3. suction lino Tho plug valv; may be uped ao a 4. diochargo line 1. throttle valve ,1 2. aoloctqr valve 3. neodlo valve 4.. chock valve Learning Objective: Identify the various kind° and type° of chipboard 5-16. What typo of valve in wed in a lino valvoo, including construction / whore the flow of fluid through an open- feature°, their location°, and ing cunt bo regulated gradually and functiono. Textbook page° 127 through exactly? 134. tJ 1. Pioton 2. Needle 3. Gate 5-10. Refer tp textbook figure 10-14.Which 4. Globe parto of the globe valve move when the handwheel in turned counterelockwioe? 5-17. You can rortii; a fully opened butterfly 1. Stem and dick -valve to its fully cloned pooition by 2. Gland and flange 1. doprepoing a pushbutton 3. Bonnet and bushing 2. turning the handle to the opPIPoite 4. Packing and otop ring pooition 3. lifting up on the handle 5-11. The special dooign of back °eating valved 4. turning the handle ono-fourth a turn makeo it p000ible to operate them fully opened with no leakage pant the packing. 5-18. The owing check valve opono only when the 1. inlet pm:lour() in greater than outlet 5-12. Fluid io permitted to flow through the 'preonure body of a globe otop valve by turning 2. outlet pronnuro in greater than inlet the handwheel in the direction which will prepoure cause the 1. inlet prepoure in greater than spring 1. dick to lift off the valve neat tenoion 2. dick to fit tightly againot the valve 4. outlet prennure in greater than opting coat tenoion 3, stem to pull away from the packing 4. stem to make contact with the packing 5-19. Whethof a ollap-check valve act° ao a otop gland valve or ao a check valve depend° on the 1. pooition of the control lover 5-13. In which way doe° a gate valve differ from 2. direction of flow a globe valve? 3. typo of dick inotalled 1. Path of the fluid through the gate 4. pooition of the stem valve in straight, through the gI'obe valve the path in not straight 5,-20. The double-poppet throttle valve in 2. Flow in regulated by degree° through actuated by the gate v lve but not through the 1. manual force and power from an globe valv electric motor /- 3. The gatealvo workn well ao a throttle. 2. mapUal force and power from a hydraulic valve, the glObe valve doeol.not motor 4. The gate valve in uped in, fuel linen 3.. steam preooure within the valve and only, the 'globe valve in water linen manual force 4. oteam prenoure within the valve and power from a hydraulic motor" 5-21.IA rol(ofvalvo lo'a typo of sure- control valve that io docti6 d to open automitically when lino projeuro lo too Learning Objeetivo: Delineate high. chipboard piping, including pipe definition°, pipe cntOrialo, pipe 5-22. Uhothor a relief valve iD of the dick fitting°, socket° and packing, typo or ball type, it lo kept eloped by °trainer°, otcam trope, and drain°. the Textbook page° 135 through 141. 1. compreoolon of a °tool spring 2. woight of ito valvo body 3. annual forco with which ito stem lo turned 5-26. Pipe deoignationo that refer to the wall 4. reactive force opposing the manual thickn000 on the pipe include force uped to turn its stem 1. otandard 2. extra otrong 5-23. Reducing valvoo uoed in roduced proaaure 3. double extra otrong lino° aboard chip are deolgned to 4. all of the above 1. prevent damage to the lineo due to (=cooly° preaoure 5-27. If the nominal ID of a auble extra 2. keep operating propoure oqual to otrong pipe lo 7 infheo, ito actual ID Jo supply prepoure 1. leo° than the actual ID of a 7-inch 3. vary operating proof:Jure according extra otrong pipe to demand more than the actual ID of a 7-inch 4. provide a °toady proof:Jure lower than extra otrong pipe the supply proof:Jure 3. more than the actual ID of a 7-inch otandard pipe 5-24. Uhat is one of the factor° that the opera- 4. more than 7 inches tion of a reducing valve depend° upon? 1. The valve maintains outlet prepourn The °ire of tubing lo generally expressed k5-28. and inlet prof:Jour° in equilibrium in term° of its 2. The valve maintain° outlet prof:Jour° 1. actual inside diameter at one-half the inlet proof:Jure 2. actual inside circumference 3. The inlet preaaure controls the rate 3. nominal outoide diameter at which outlet oteam woe° throUgh 4. nominal outoide circumference the valve 4. The outlet proof:Jure controlo.the 5-29. Steam and fuel OVfitOMP i.board rate at which inlet oteam paopeo chip are made of through the valve 1. °tea 2. copper 5-25. A relief valve to never installed ac a 3. braoo safety ualve on the oteam drum of a 4. copper-nickel alloy boiler. Why? 1. It will not remain open long enough 5-30. What type of oteel tubing io ugually for blowdown to occur used for high-prpooure, high-te erature 2. It will not pop ate °pacified prep- titeam cervico? pure 1. SeaMleao carbon steel 3. It will not clooe tightly without 2. Molybdenum alloy oteel chattering nor remain- closed long 3. Chromium alloy steel enough after °eating 4. Welded carbon steel 4. It io not installed because of all the above reaoono 5-31. The composition of the gaoket material °elected for use in a piping oyotem depends upon all of the following except temperatures to which the fluid carried in the system will be oubjected 2. prof:mum° to which the fluid carried in the oyotem will be oubjected 3. kind of fluid carried in the system 4. number of atrainero installed in the oyatem . 2.3 p 28 5-32. On naval veoosflo, condensate io removed 5-39. What io the difference between the gyrate= from steam lnea by means of for delivering current from the a-c 1. mechaAical atom crape generator and from the d-c generator? 2. thermeotatic oteam trapo 1. In the d-c generator, current flowo 3. impuloe oteam trapo from the commutator to olip ringo 4. drains and mechanical, thermootatic, to the circuit; in the a-c generator, and impulse steam traps it flows from the otator to bruoheo to the circuit 2. In the d-c generator, current flowo from the rotor to atator to the Learning Objective: Recognize the circuit; in the a-c generator, it inherent hazards of electricity flowo from the rotor to the circuit and °beery° all oafety procautiono 3. In the d-c generator, current flowa when working with or near electrical from the commutator to bruoheo to ayotems and equipment. Textbook pages the circuit; in the a-c generator, 142 through 154. it flown from the otator to the circuit 4. In the d-c generator, current flown from thealip rings to the bruahec 5-33. Which of the following oubotancen offero to the circuit; in the a-c generator, the moot reolotance to electric current? it flown from the bruaheo to the 1. Iron rotor to the circuit 2. Mica 3. Aluminum 5-40. Revolving-field generators are superior 4. Copper to revolving-armature generatora in that they 5-34. The rate at which a current paoaen 1. have their load current from the through a lighting circuit is measured in atator connected to the external '1. watto circuit without the uoe of slip rings 2. volta 2. need only two clip ring') to supply 3 ohms 44z excitation to the revolving field 4. amperes 3. do not have their atator windings subjected to mechanical stressed due, 5-35. A unit of electrical reniatance in the to centrifugal'forces 1. watp 4. have all the above features 2. ogir 3. ampere 5-41 What provision Jo made to prevent a high- 4. volt speed turbine-driven alternator from overheating? 5-36. Anaume that a soldering iron is rated at 1. A forced ventilation system circulates 100 watts. This information tells you air through the stator and rotor about the 2. The alternator is used in conjunction 1. power consumed by the iron with others and automatically goes 2. realatance of the iron off when it becomes warm 3. 'emf of the iron 3. A heat-limiting Overnor controls the 4. rate at which current flows through temperature the iron 4. The alternator parte are encased in a metal structure that is surrounded by 5-37. A shipboard generator operates at greatest cold water efficiency lallen operating 1. in eerier, with other generators of 5-42.' What is the source of energy for the same rated output turbines that drive a ship's service 2. at 1$11 rated output generators? 3. at Yerioda of minimum power demand 1. Saturated steam 4. with batteries fully charged 2. Superheated steam 3. Diesel engines 5-38 The rotatiqiRmember of a d-c generator is 4. Batteries t usually called the 1. armature 2. yoke 3. field winding 4. rotor 237 29 5-43. One °pacification that all ohipo oervice 5-50. What io used to oupply (1...c power to generator° cunt meet Jo that they the d-c loado on the new ohipo that 1. oupply at leaot 600 volto of elec- have a-c power planto? tricity 1. Rectifier° 2. operate at a conotant °peed 2. Motor generator° 3. be able to run indefinitely without 3. D-c generatoro shutdown 4. Emergency generator° 4. oupply alternating and direct current to ohipo circuito 5-51. What device in a ohipboard electrical oyotem will operate when power io ouddenly 5-44. Why are emergency generators aboard Navy applied to a gun mount and to the anchor ohipo dieoel driven rather than turbine windlaoo at the-oame time? driven? 1. Circuit breaker 1. Dieoel engine° can generate tore 2. Rheootat power than turbine° 3. Voltage regulator. 2. Dieoel engines can °tart faster than 4. Emergency generator turbine° 3. Dieoel engine° are copier to operate. 5-52. Although °team Jo readily available than turbine° aboard moot °hip° to drive auxiliary 4. There io leo° danger.e4 fireo from machinery, electric power ie uoed for dieoel engine° than from turbines moot equipment located outoide the machinery °paces. Electric cable io 5-45. The control switchboard on a destroyer superior to °team piping for transmitting hao inotrumento and control° for paral- power because it io leling the forward and after ohip's 1. more eaoily controlled, leoo eaoily oervice generator° and for equalizing damaged, and more durable the load between them. 2. more durable, more eaoily repaired, and more convenient 5-46. The automatic voltage regulator maintaina 3. less eaoily damaged, Gofer, and more conotant voltage during load change by easily controlled varying 4. more eaoily controlled, Gofer, and 1. armature reoiotance more convenient 2. field excitation 3. generator opeed 5-53. Which of the following piecea of equip- 4. governor °peed mentmay be equipped with electric broken? 5-47. Switchboards on Navy ohipo are provided 1. Anchor windlass with fuses instead of automatic tripping 2. Switchboards circuit breakers to protect against 3. Generators voltage failure. 4. Auxiliary pumps 5-48. Which of the followingtroubles will 5-54. Shipboard motor controllers are used for cause an ,a-c generatorcircuit breaker 1. starting and stopping motors to trip? 2. increasing and decreasing motor 1. Gun fire speeds 2. Power reversal 3. reversing the direction of rotating 3.4 Short circuit in alighting circuit motor shafts 4. Short circuit in afresh water pump 4. all the above purposes 5-49. Emergency generators provide electric 5-55. The presence of salt water in the elec- power to trolyte of a battery can set up a 1. emergency lighting 4 chemical reaction that is damagng to the 1 2. limited lighting and vital auxiliaries Battery. 4 3. limited auxiliaries 4. fireroom auxiliaries 5-56. Assume that you are assigned to a shiplo boat as boat engineer. If you see the bowhook poudding on a steel bolt with a steel hammer in the vicinity of the battery compartment, you should stop him immediately in order to prevent 1. damage to the battery case 2. serious inidry from spilled electro- lyte 3. electrical shock 4. a possible battery explosion 30 238 5-57. The roloy-oporoted bottle lantorn in on 5-61. Power and lighting distribution (*lot= emergency lighting ,circuit auto- vary in that the matically whon the 1. oyotems have different power sources I. emergency switchboard is energized 2. over diotribution systems carry 2. relay Jo connected to the circuit h her voltages 3. power to the circuit Jo phut off 3. power diotribution systems are more 4. switchboard emergency circuit is n oroua clooed 4: ighting diotribution oyotemo have larger cobloo 5-58. Rand (battle) lanterns installed through- out the ship that pro not connected to 5-62. If o ohipio service generators furnish relays are used for current at 445 volts, what devices are 1. explooion proof light when needed in used to atop down the voltage to operate newly opeRld voids 110- to 120-volt equipment? 2. nocesoary lighting when shifting 1. Rheostats generators 2. Controllers 3. Droop not covered by the lighting 3. Transformers distribution (*Totem 4. Voltage regulotora 4. emergency use only 5-63. Only Electrician'o Mateo or I. C. Elec- 5-59. Portable power tools in use on Navy ships triciano ohould topoir electrical equip- are provided with three conductors, the ment aboard a Arlo. third conductor is to 1. provide heavier loads for heavier 5-64. You are repairing a motor-driven pump. work The motor circuit contains o switch. 2. protect operators from shock You will be observing electrical safety 3. permit reversing of dud-tool precautions' when you have an electrician 4. provide emergency service if one of 1. disconnect the motor from the circuit the conductors is damaged by opening the switch 2. attach a warning tag to the switch 5-60. Normally, electric current for the lights 3. connect the motor to the circuit by in a ship's machinery spaces is conveyed closing the switch after the repair by power distribution system, work is done 4. do all the above It 31 239 Assignment 6 Internal Combustion EnAineo and Engineering Watches Textbook Asoignment: Chapters 12 and 13 6-5. In the operation of a gasoline engine, the force that puoheo the piston downward /? Learning objective: Recognize the io the aoic principles of internal com- ib 1. compression of fuel-air mixture bustion engines. Textbook pages 2. intake of fuel-air mixture 156 through 158. 3. expansion of burning gapes 4. removal of burned [poen 6-6. During which of the following piston .6-1. An internal combustion engine converts otrokeo is power furnished to the crank- 1. thermal energy to mechanical energy shaft by the piston? through the use of steam 1. Intake, compression, power, and 2. mechanical energy to thermal energy exhaust through the burning of fuel in 2. Intake, compression, and power cylinders 3. Compression and power 3. thermal energy to mechanical energy 4. Power through the burning of a fuel-air mixture in cylinders 6-7. Which of the following events in the 4. mechanical energy to thermal energy operating cycle of a diesel engine does through the use of steam not take place in the operating cycle of a gasoline engine? 6-2. Combustion takes place in (A) a diesel 1. Injection of fuel engine and (B) a gasoline engine as a 2. Compression of air result of ignition by 3. Expanoion of gases 1. expansion of compressed gases in A and 4. Removal of burned gases by a spark in B 2. heat of compression in A and by a spark 6-8. With respect to which factor must 2-stroke- in B cycle diesel engines differ from 4-stroke- 3. a spark in A and by heat of compression cycle diesel engines? in B 1. Number of pistons 4. a spark in A and by expansion of 2. Piston arrangement A compressed gases in B 3. Number of piston strokes in a complete cycle 6-3. The one-way distance a piston travels 4. Distance a piston travels during a between its upper and lower limits of stroke travel in a cylinder is referred to as a 1,7cycl 6-9. When the piston nears the bottom of the at ke power stroke in the 2-stroke-cycle engine, 3. s roke-cycle what is forced through the cylinder intake 4. revolution ports? 1. Fuel oil 6-4. During the intake stroke of a piston in a 2. Scavenging air 4-stroke-cycle diesel engine, the piston 3. Lubricating oil moves downward and draws a charge of air 4. Cooling water into the cylinder through open intake valves while exhaust valves remain closed. .10 2i0 32 6-10. Which of tho'following reasons partially 6-13. Which letter of figure 6A refers to the accounts for the failure of a 2-atroke- part of a can that io known ao the cam cycle engine to produce twice thepower flat? of a 4- stroke -cycle engine of thecame 1. A aloe? 2. B 1. Some power developeq, the 2-atroke- 3. C cycle engine io used to force air 4. D C) into each cylinder 2. Lean than all the combuotion,ganea 6-14. The exhaust valvea in the cylinders ofa are scavenged from each cylinder of diesel engine are opened by action of the the 2-atroke-cycle engine 1. crankshaft 3. For a given air-fuel mixture, leas 2. connecting rode fuel and air enter the cylinders of 3. valve apring the 2-atroke-cycle engine 4. camshaft I 1!, 4. Any of the above reasons 6-15. The motion of the cam in a diesel engine is tranamitted to the exhaust valves-by the action of the Learning Objeei,ive: Identify the 1. rocker arm and the bridge Alain componentortbe.dieuel.crigine 2. rocker lever shaft and the bridge indicate the r fpnctiono. fOXtbook 3. rocker. lever shaft and the cam. roller pages 159 through 164. 4. rocker arm and valve guide 6-16. In a 2.-stroke-cycle engine, howmany times does the camshaft turn as the crankshaft 6-11. The combustion chamber of a one-cylinder makes 16 turns? diesel engine io sealed off from the 1. 8 crankdaae by 2. 16 1. a piston and its rings 3. 32 2. an exhaust valve and an intake valve 4. 64 3. a piston and an exhaust valve 4. a piston and an intake valve 6-17. The speed of a reciprocating engine is the same as the speed of the engine's 6-12. The part of a diesel engine used to crankshaft. Relative to engine speed, change rotary motion to intermittent how fast does the camshaft of an reciprocating motion is the 8-cylinder, 4-stroke-cycle engine turn? 1. crankshaft 1. One-eighth as fast 2. driveshaft 2. One-fourth as fast 3. bearing 3. One-half as fast 4. camshaft. 4. Twice as fat 6-18. During the intake stroke ofa 4-stroke- cycle engine, air is forced into the cylinder by - 1. atmospheric pressure 2. the pressure of exhaust gases 3. rotary blowers 4. unit injector 6-19 Describp the changes in the temperature arid volume of the air ina cylinder of a reciprocating engine during thecompres- sion. stroke of a piston. 1. Temperature increases; volume decreases 2. Both temperature and volume increase 3. Temperature detreases; volume . increases 4. Both temperature and votume decrease Figure 6A 241 33 4 6-20. Which-of the following compression rttios 6-26. Fresh water and salt Water are both used io typical of diesel engines? as coolinwagents in a type of diesel 1. 4:1 engine. In this engine the function of 2. 5:1 the sea water is to 3. 10:1 1. cool the fresh water after it cir- 4. 5:1 culates through the engine 2. replace the fresh water when its Items6-21 through 6-23 refer to the fuel"" temperaturF:exceeds 212° F auppl ayotem of texthlbok figure . 3. supplement the supply of fresh water lost due to evaporation 6-21. Which c mponent functions to meter, 4. sloW,down the cooling process when pressurize, and atomize the fuel? higher engine operating temperatures 1. Fuel pump are desired 2. Inlet manifold 3. Injector 6-27. How long may the electric starter 4. Outlet manifold motor for a diesel engine be operated? 6-22. Which component &there for the last time 1. 30 to 0 .seconds the fuel that enters the combustion 2. 30 se onds chamber of the engine? 3. 2 to minutes 1. Primary filter 4. 3 to 5 minutes 2. Secondary filter 3. Fuel pump 4. Injector Learning Objective: Identify the 6-23. The speed of the engine is controlled by main components of the gasoline varying the amount of fuel in ected into engine and indicate their functions. the cylinders of the engine. The fuel Textbook pages 165 through 169. charge is varied by 1. rotating the plungers inhe unit injectors t. 2. enlarging the holes in the injector 6-28. In a gasoline engine carburetor the nozzles mixture ratio is the number of er47 3. increasing the capacity of the fuel 1. pounds of gasoline vapor mixed with pump each pound of air 4. changing the compression ratio of the 2. cubic feet of air mixed with each engine cubic foot of gasoline vapor 3. pounds of air mixed with each pound 6-24. Which of the following types of action of gasoline vapor would most likely be necessary if the 4. cubic feet of gasoline, vapor mixed lubrication system of an internal com- with each cubic foot of air bustion engine should fail? 1. Main oil line should be flushed out 6-29 Which of_the components of a gasoline 2. Oil pYessure gage should be replaced engine ignition system belong to the 3. Camshaft gear and crankshoft gear secondary circuit of the system? should be cleaned 1. Battery, ignition switch, and breaker 4. Engine should be completely overhauled points 2. Distributor cap, distributor rotor, 6-25. The engine should be secured until the and spark plugs trouble is located and corrected if 3. Battery, spark plugs, and condenser 1. the oil pressure should drop to lower 4. Distributor cap, breaker points, and than normal coil 2. the temperature"of the oil should rise abnormally- 64-30. The device that serves as a selector 3. either 1 or 2 above should occur switch for channeling electricity to the 4. the oil strainer should become clogged individual cylinders of a gasoline engine is the A 1. condenser 2. ignition switch 3. distributor 4. ignitiodcoil 34 242 6-31. In the primary circuit of a gasoline 6-38. Advantages of the gas turbine engine over engine ignition bystem, current flows the diesel, engine include all of the from the ignition coil directly to the folibwinexcept 1. spark plugs 1. less bration at full power 2. distributor rotor 2. smalle number of components 3. breaker points 3. faster adjustment to varying loads 4. battery 4. smaller components for air inlet and exhaust 6-32 The breaker points of a gasoline engine are protected from burning by 6-39. Which events occur in the forward section 1.. a condenser of the gas-turbine engine? 2. a coil 1. Compression and combustion 3. a ground to the engine frame 2. Compression and expansion 4. ins tors 3. Combustion and expansion 4. CombustiOn, compression, and expansion 6-33. A recommended method of cleaning.fouled spark plugs is to 6-40. Which of the following parts are 1. soak'them in cleaning fluid in the power 9tput section of a gas 2. wirebrush or sandblast them turbine? 3. rub them with an emery cloth 1. Compressor 4. scrub them with warm soapy water 2. Burner 3. Reduction gear 4. Nozzle Learning Objective: Identify the 6-41. All of the following gas-turbine engine main components of the gas turbine accessories are driven by the rotor engine and indicate their functions. except the Textbook pages 167 through 169. 1. fuel pump 2. governor 3. oil pump 4. overspeed switch 6-34. Gas turbines are like reciprocating engines in which of the following respects? 1. Air is compressed Learning Objective: Recognize safe 2. A fuel-air mixture is burned procedures in the operation of small 3. Combustion gases are ended in boat engines. Textbook pages 169 developing power and 170. 4. All of the above respects 6-35. In gas turbine engines compression, com- bustion, and expansion take place in 6-42. You are the engineer of a ship's small three separate components while in boat and the coxswain rings three bells. reciprocating engines these events occur What does this signal mean? in only one component. 1. Full speedn the direction in which you are ng 6-36. Which component serves the gas turbine 2. Ahead ow engine as the pistonjerves the recipro- 3. Rever cating engine? 4. Neual 1. Burner 2. Turbine 6-43. After ou start a cold diesel engine, 3. Rotor your next step is to run it at 4. Compressor 1. low speed until it warms up 2. ,low speed for a minute so you can 6-37. One advantage the gasoline engine has check the supply of lubricating oil over the gas turbine is that the gasoline 3. top speed so you can check the fuel engine / and cooling systems for leaks 1. uses less explosive fuel 4. top speed so you can check the oil 2. consumes fuel at a slower rate pressure 3. needs fewer moving parts 4. accelerates rapidly from cold starts a. 35 243 6-44. If you find that the ex1aust of the diesel 6-49. What is the maximum time lapse between engine of a small boat indicates no suc- routine entries in the operating log? tion by the water pump during warm-up, 1. One half-hour you.should 2. One hour 1. stop the engine 3. Four hours 2. pheck,the cooling systeni for clogged 4. Twenty-four hours strainers 3. check the cooling system for closed 6-50. If a ship's workday ends at 1600, when sea valves is the most likely time period for stand- 4. do all the above ing the sounding and, security watch? 1. 1600 to 2000 6-45. A diesel engine has stopped running 2. 1600 to 2400 because fuel is not'xreaching the engine 3. 1600 to 0400 cylinders. Enciligh fuel remains in the 4. 1600 to 0800 tank. A possible cause of engine failure is 6-51. A sounding tube is generally constructed 1. an accummulation of water in the of strainers 1. 1/2-inch pipe 2. a plugged vent in the tank filler cap 2. 1 -iechpipr 3. a lack of either oil or cooling water 3. 1 1/2-inch pipe 4. either 1 or 2 abov) 4. 2 -inch pipe 6-46. When a gasoline-powered boat is being ^6-52. Why are some sounding tubes constructed driven, which of the following pre- so that they terminate in risers extend- cautions is needed in addition to those ing about three feet above the ship's that apply to a diesel-powered boat? compartment to be served? 1. Being sure that there is enough 1. They are unable to be extended to cooling water the upper decks 2. Being sure that the vent in the fuel 2. They are straight tank filler cap is not plugged 3. They have an upper end terminating 3. Seeing that the engine compartment is in a flush deck plate ventilated so as to pievent an accu- 4. They have a closed threaded plug mulation of flammable vapors 4. Seeing that there is an adequate 6-53.Assume that a sounding tape shows a read- supply of lubricating oil ing of one fooof liquid in a normally dry compartment. What action should be 6-47. The cause of fuel system failure in a taken? diesel driven boat is often found to 1. Wait until the next time you take be soundings to see if the level has 1. improper cooling increased 2. water in the strainers 2. Notify the main engineroom so that, 3. an ungrounded fueling hose the level of liquid can be recorded 4. faulty spark plugs 3. Pass the word about the liquid level to your relief 4. 'Notify'your watch supervisor immediately Learning Objective: Recognize the duties and responsibilities of 6-54. Why should you coat a sounding rod wfih the FIREMAN standing engineering white chalk bef e taking a sounding of a watches in port and underway. water tank? Textbook pages 170 through 176. 1. To enable the rod to slip through the r sounding tube without bending 2. To make it easier to see the dividing point between the dry and wet parts 6-48. Which assignment is usually carried out of the rod by the messenger of the watch during close 3. To facilitate leering the rod in the maneuvering conditions with other ships? sounding tube 1. Shaft alley watchstander 4. To keep the rod from hitting the 1 I-1- 2. Telephone talker on the engineering bottom of the tank with enough force JV circuit to damage the rod 3. Evaporator operator 4. Throttleman 4 2i4 36 6-55: Assume dint you areon a cold=iron watch 6-64. You can ldarn how a normal reading of and-you find that a welder is welding a throttleboard differs from an abnn in your area without a fire watch. What reading.by studying the throttleh action should you take first? d and asking the throttleman questions. 1. Stop the welding 2. Report to the OOD 6-65.,4ich watchstander in the engineroom is 3. Station a fire watch responsible for keeping both the standby 4: Bring a fire extinguisher to thearea main feed pump and standby lube oilpump ready for instant,mse? 6-56. When your ship is in drydock, feed water 1. Pumpman may not be shifted without permission 2. from the Upper level watchstander " 3. Shaft alley watchstander 1. officer of the deck 4. Evaporator watchstander 2. chief machinist's mate 3. engineer officer 6-66. Who is responsible for maintainiqg the 4. chief boiler technician proper water lever-in a deaerating feed tank located in the engineroom 6-57. Which of the following jobs will a 1. Pumpman burnerMan carry out on a shakedown CrU 2. Upper level watchstander while his ship is maneuvering? 3. Checkman 1. Control forced draft blower 4. Evaporator watchstander 2. Warming up standby fuel oilpumps 3. Performing routine maintenance 6-67. A Fireman Apprentice should learn 4. Cutting burners in and out his duty stations under various conditions 4 6-58-c ir of battle readiness by DurIng'regular steaming operations, which 1. checking with his division. officer watchstanders in the fireroom must frequently cooperate with -each other in mars 2. memorizing the duties of his watch that concern the burning of fuel oil? 3. followit!g the ordeN of the petty 1. :Blowerman and burnerman fthe watch 2. Checkman and burnerman 4. checking the Watch, 3. Messenger and blowerman Quarter, and Station,dill frequently 4. 'Messenger and checkman In items 6-59 through 6-63, selectfrom column B the fireroom-watchsnder who performs the job 1 listed in column Assume that.feed water is being controlled ually. A. Job Watchstantler 6-59. Adjusting the 1. Mess air registers 2. Burnerman 6-60. Maintaining the proper water 3. Blowerman lakrel in the boiler 4. Checkman 6-61. Regulating fuel oil pressure at the burners 6-62. Recording tempera- ture and pressure readings in the operating log C 6-63. Controlling the forced 'draft blowers ir US GOVERNMENT PRINTING 0I-FICL 19/b- 641-277:30 37- 245 a COURSE bISENPOLLMENT' . All study materials must bereturned. On disenrolling, fill_out only the upper partof this page and attach it to the inside frontcover of the te04book for this ( course. Mail your study,paterials to theNaval \ Education and TrainingProgram Development Center.' PRIN`r CLEARLY 1 NAVEDTRA Number COURSE TITLE 10520:E FI IAN Name Last First ' Middle . . Rank/Rate ..9 Designator ,Social Security Number' , 7 COURSE COMPLETION Letters of.satisfactory completionare issued only bp personnel whosecourses are administered by the.Naval Education and Training ProgramDevelopment Centez. On completing the course,-filloutthe lower partofthis page and enclose it with your last-setof self-scoied answer sheets. Be sure maTling.Wressesare complete: Mail to the Naval Education and Trainimg. Program - ' Development Center.-,, 7 ao NAME 1:5 ZIP CODE k MY SERVICE RECORD IS HELD BY: I Activity Nr, Address ZIP CODE a S .gnature 00\ enrollee .16 POD Form 111 0 246 A FINAL OUZSTION: That did you think-of this course? with the course? Comments and Of the text material used recommendationo.received from enrolleass'have , a major source of course improvement. You and boon' your command are urged to submit constructive criticisms andyoy your recommendations. This tear-out formletter is provided for your conveniinte.Typewrite if possible, but legiOle _acceptable. handwriting is° Date From: ZIP CODE To: Naval Education and TrainingProgram Development Center Building 923 4 Pensacola, Florida 32509 Subj: RTM/NRCC FIREMAN, NAVEDTRA10520-E 1. The following conuflntsare hereby submitted: .r 247 .1. (Fold alok; dotted linO and staple or tape) 7 0 (Fold along dotted line and staple or tape) DEPARTMENT OF THE NAVY NAVAL EDUCATION AND TRAINING PROGRAM POSTAGE AND FEES PAID DEVELOPMENT CENTER (POD 4) DEPARTMENT OP THE NAVY PENSACOLA, FLORIDA 32509 000410 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE. S300 V. NAVAL: EDUCATION AND TRAINING PROGRAM DEVELOPMENT CENTER (PDD 4) BUILDING 923 A PENSACOLA, FLORIDA 32509 248