DOCSLIB.ORG

A Guide to Permanent Way Design

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Guide to Permanent Way Design A Guide to Permanent Way Design by Paul King A Guide to Permanent Way Design A Guide to Permanent Way Design Contents Page No Introduction 2 Horizontal Design a. Basic Elements 3 b. Cant and Deficiency 5 c. Transitions 8 Vertical Design a. Terminology 11 b. Constraints 11 c. Design Methods 12 d. Design for canted track 13 e. Calculation example 14 Switch and Crossing Geometry a. Basic elements 16 b. Switch details 17 c. Crossing details 18 d. Turnout types 19 e. Speed characteristics 20 f. Design guidelines 20 Track Layouts 22 Clearances and Vehicle Envelopes 25 Hallade Design 35 Survey Requirements a. S&C 43 b Plain Line 44 Author – Paul King Date – September 2011 - 1 – Copyright – P.J. King A Guide to Permanent Way Design Introduction This booklet is the combination of a series of design lectures given by me over the past ten years. The intention was to provide the beginner / novice with simple guidelines to give an appreciation of the basics elements of track design starting with horizontal and vertical design. These are the basic elements upon which track design is built. Sections are also included on switch and crossing geometry, clearances and track survey requirements. Network standards have been referenced where appropriate. It should be noted that these do change from time to time. - 2 – Copyright – P.J. King A Guide to Permanent Way Design Track Geometry Horizontal Design – Plain Line a. Basic Elements i. Elements of STRAIGHTS and CIRCULAR CURVES Design They can be linked by spirals known as TRANSITIONS. Transitions can also link different curves. They are not elements but LINKS. ii. Definitions STRAIGHT- Shortest distance between 2 points, line of constant bearing. CIRCULAR CURVE - Line that is a fixed distance (radius) from a point (circle centre). TRANSITION - Curve of constantly changing radius – a spiral. Diagram 1 – Low speed layouts – Typically sidings (Element) (Element) Tangent Point Diagram 2 – Main Line arrangement (Element) Tangent Point (Link) (Element) Note – Tangent point is where 2 elements or an element and a link meet. - 3 – Copyright – P.J. King A Guide to Permanent Way Design iii. Theory Why have straights? Easy to design, set out and maintain Constant force on track from train wheels Shortest-quickest – distance to travel Why have Circular curves? Constant force from train wheels which can be offset by cant (see later) Easy to design, set out and maintain Transitions – They avoid an instant change of radius, which What are they for? would be very noticeable at high speed inside the train – see rules in following section. Provide area for cant (super elevation) –– to be built up. See following section for details. Transitions – What shape? This depends on design method used but all are very similar 1. Hallade – Cubic Parabolic 2. Mx or BRT – Clothoid or Bloss ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - 4 – Copyright – P.J. King A Guide to Permanent Way Design b. Cant and Deficiency Rails inclined at 1:20 (to match train wheels) i. Straight Track towards track centre Diagram 3 Cant = Difference in rail levels Note – Track gauge (G) = 1435mm or 1432mm for older Cen56 designs (Distance between inside edges – running edges - of rail) Other Typical Dimensions Depth of Track Construction (D) = 365mm Length of Sleeper (L) = 2500mm – 2600mm ii. Curved Track Diagram 4 W - Weight of vehicle F - Acceleration force R – Resultant of W&F E – Cant/mm E = 11.82V2 For R = W+F R 1 R = Radius in metres V = Speed in Kph - E = Equilibrium cant in millimetres – Train wheels exert no sideways force on the rails - 5 – Copyright – P.J. King A Guide to Permanent Way Design Generally a cant less than E is applied because: E is designed for the maximum speed and not all trains run at this speed Applying a lower cant will result in a force between the high wheel and the rail – this ‘guides’ the train around the curve Reduces contact fatigue To apply a cant less than the equilibrium will result in a deficiency. This value is called the ‘CANT DEFICIENCY’ (D). (It creates an outward force on the high rail (Y)). The designed cant (Ea) and deficiency total the equilibrium cant: Ea + D = E iii. Limiting Values Non tilting trains These are shown in Railtrack standard NR/L2/TRK/2049 – Track Design Handbook (TDH) – pages B2.1 – B2.4. The cant deficiency (for conventional trains) should not normally exceed 60% of the applied cant on jointed track or 73% of this figure for continuously welded track (CWR). Exceptionally these figures may be increased to 73.3% and 100% respectively. This can be summarised: Jointed Track - Dmax = 0.6Ea = 0.375E Dexp = 0.733Ea =0.423E CWR Track - Dmax = 0.73Ea = 0.422E Dexp = Ea =0.5E The above maximum values apply to a general cross section of lines. High speed lines should be designed such that the deficiency is a minumum of half the cant: D = 0.5Ea = 0.667E - 6 – Copyright – P.J. King A Guide to Permanent Way Design The maximum values of cant and deficiency are shown in the TDH on Pages B2.1 – 2.3, these can be summarised: Jointed Track - Dmax = 90mm Dexp = 110mm Emax = 150mm Eexp = 180mm CWR Track - Dmax = 110mm Dexp = 150mm Emax = 150mm Eexp = 180mm The maximum and not exceptional figures should be generally used. iii. Limiting Values Tilting trains Tilting trains can run at what’s known as Enhanced Permissible Speed (EPS) – conventional trains run at Permissible Speeds (PS). PS characteristics have generally been shown throughout this paper. At EPS speeds the maximum permitted cant deficiency is 265mm and this depends on the radius. For full EPS data refer to the TDH on Page B2.2. iv. Calculation Example Determine Ea for the following: V = 50 mph (x by 1.609 for Kph) R = 500m If D = 0.5Ea Using equation 1 E = 11.82 v2/R E = 11.82 x (50 x1.609)2 500 E = 153.00mm Ea = 0.667E = 102mm In practical terms cant is set in 5mm increments therefore: Ea is set as 100mm D = 153 – 100 = 53mm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - 7 – Copyright – P.J. King A Guide to Permanent Way Design c. Transitions As previously defined these are links between curved and straight tracks (or curve to curve), they are a form of spiral which smoothly forms the link. Diagram 5 (Element) (Link) Tangent Point (Element) Transitions are needed on all alignments except: Sidings Low speed areas such as stations/depots Compound curves of similar radii Where cant is applied to a curve this is built up at a constant rate through the transition. (Transitions are usually marked on site showing the cant at 5mm steps, the limits of the transition are also marked.) i. Design Requirements Having determined the cant required for the circular curve an appropriate length of transition needs to be designed. This is done by using limiting values laid down in the Track Design Handbook (TDH). These are shown on page B2.1. The two critical factors are: Cant gradient (Egrad) Egrad = 1 in Transition length (TL)/Ea 2 Rates of change (RoC) of cant (Ea) and cant deficiency(D) RoC = (Ea or D) x V (mm/second) 3.6 x TL 3 TL = Transition length in metres If the transition links two curves, Ea = Ea1– Ea2 for curves 1 & 2. Similarly D = D1 – D2. - 8 – Copyright – P.J. King A Guide to Permanent Way Design ii. Limiting Values TDH page B2.1 Cant gradient = 1 in 400 – 1 in 1500 ( normal limits) Rate of change Ea or D = 35mm/sec desirable 55mm/sec maxiumum 70mm/sec exception maximum The above values for rates of change do not apply to tilting trains, these are 35mm/s, 110mm/s and 150mm/s respectively from the TDH page B2.3. A practible arrangement is to fix the change of cant at 1mm/ sleeper. This gives values of between 1:600 and 1:760. iii. Calculation example TL to be determined from the following values: V = 50mph R = 500m E = 100mm From equation 3 using a rate of change of cant of 35mm/sec we can calculate TL using either Ea or D whichever is greater. From the example worker in section 2 it can be seen that Ea is the critical factor here. 35 = Ea x V 3.6 x TL TL = Ea x V 35 x 3.6 = 100 x (50 x 1.609) 35 x 3.6 TL = 63.84m It would be usual to round this to the nearest 5m to make it a ‘tidy’ length. Therefore TL = 65m Check this for gradient limits using equation 2 Egrad = 1 in 65/0.1 ( units in m) Egrad = 1 in 650 This is within the limits as outlined above and is acceptable. - 9 – Copyright – P.J. King A Guide to Permanent Way Design iv. Additional Information i) For curve equations – See TDH pages C2.1 – C2.5 v. Summary a. The elements in horizontal alignment are straights and circular curves, they can be linked with transitions. b. The applied cant is a factor of the square of the speed divided by the track radius. c. Cant is always designed with a deficiency. d. Transitions are fixed by their length and are determined by the rate of change of cant or deficiency and cant gradient. vi. References a. Design Methods – MX Rail Bentley Railtrack Hallade – See section 1F b. Standards Factors concerning speed, cant and transitions are shown in the TDH section B. For mathematical formulae regarding curves and transitions see section C of this document. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - 10 – Copyright – P.J. King A Guide to Permanent Way Design Vertical Profile Design To accompany any horizontal track design a vertical profile will be needed.
Load more

Recommended publications
  • Annual Report of the Board of Regents of the Smithsonian Institution
    THE DEVELOPMENT OF THE AMERICAN RAIL AND TRACK, AS ILLUS- TRATED BY THE COLLECTION IN THE U. S, NATIONAL MUSEUM. By J. Elfreth Watkins, Curator of the Department of Transportation and Engineering. In the brief report upon the section of steam transportation for the year 1887, a statement was made to the effect that considerable in- formation had been secured which it was hoped to use "in preparing- a series of models to illustrate the beginnings and development of the English and American systems of track. "While illustrated histories of the steamboat and locomotive are numerous, I am not aware that any systematic attempt has been made to preserve the history of the development of the systems of permanent way which, after many years of experiment, are now being reduced to a series of standards depending on the traffic." (Report of U. S. National Museum, 1887, p. 79.) These expectations were realized to a sufficient extent to warrant the preparation of the series of original rail sections, models, and drawings to illustrate the origin and development of American perma- nent way for the Exposition at Cincinnati in 1888. The interest manifested in that collection led me to present a paper entitled "The Development of the American Rail and Track" at the annual convention of the American Society of Civil Engineers, at Sea Bright, New Jersey, June 21, 1889. This will appear in the transac- tions of that society during the coming year.* At the conclusion of that paper I took occasion to state that in its preparation " I preferred to confine myself to a description of such rails as are represented by original sections, models, or drawings in the section of transportation and engineering in the U.
    [Show full text]
  • A Prototype of Track Gauge and Cant Measurement Device for Curved Railroad by Using Microcontroller
    Advances in Engineering Research, volume 193 2nd International Symposium on Transportation Studies in Developing Countries (ISTSDC 2019) A Prototype of Track Gauge and Cant Measurement Device for Curved Railroad by Using Microcontroller Rony Alvin Alfatah Wahyu Tamtomo Adi Line Building Engineering and Railways Line Building Engineering and Railways Indonesia Railway Polytechnique Indonesia Railway Polytechnique Madiun, Indonesia Madiun, Indonesia [email protected] [email protected] Dwi Samsu Al Musyafa Septiana Widi Astuti Line Building Engineering and Railways Line Building Engineering and Railways Indonesia Railway Polytechnique Indonesia Railway Polytechnique Madiun, Indonesia Madiun, Indonesia [email protected] [email protected] Abstract—The purpose of this study is to create a tool for (track gauge) and the difference in elevation between the measuring track gauge and cant in the curved railroad with outer rail and the inner rail which is called can’t on the digital systems which can improve railroad maintenance with railroad curvature using a vernier caliper sensor and an automatic recording system for more efficient and easy to gyroscope to get the parameters of the track gauge, cant of use. This tool uses Arduino IDE as an application the arch, and the temperature of the measuring instrument. programming language and microcontroller board combined with several sensors to measure many parameters of track The data can be processed and monitored directly through an gauge and cant. Android devices with a Wi-Fi connection can android device using node MCU as a liaison of an android display the measurement results display real-time data on the device with a measuring instrument via wifi connectivity.
    [Show full text]
  • the Swindon and Cricklade Railway
    The Swindon and Cricklade Railway Construction of the Permanent Way Document No: S&CR S PW001 Issue 2 Format: Microsoft Office 2010 August 2016 SCR S PW001 Issue 2 Copy 001 Page 1 of 33 Registered charity No: 1067447 Registered in England: Company No. 3479479 Registered office: Blunsdon Station Registered Office: 29, Bath Road, Swindon SN1 4AS 1 Document Status Record Status Date Issue Prepared by Reviewed by Document owner Issue 17 June 2010 1 D.J.Randall D.Herbert Joint PW Manager Issue 01 Aug 2016 2 D.J.Randall D.Herbert / D Grigsby / S Hudson PW Manager 2 Document Distribution List Position Organisation Copy Issued To: Copy No. (yes/no) P-Way Manager S&CR Yes 1 Deputy PW Manager S&CR Yes 2 Chairman S&CR (Trust) Yes 3 H&S Manager S&CR Yes 4 Office Files S&CR Yes 5 3 Change History Version Change Details 1 to 2 Updates throughout since last release SCR S PW001 Issue 2 Copy 001 Page 2 of 33 Registered charity No: 1067447 Registered in England: Company No. 3479479 Registered office: Blunsdon Station Registered Office: 29, Bath Road, Swindon SN1 4AS Table of Contents 1 Document Status Record ....................................................................................................................................... 2 2 Document Distribution List ................................................................................................................................... 2 3 Change History .....................................................................................................................................................
    [Show full text]
  • Construction Surveying Curves
    Construction Surveying Curves Three(3) Continuing Education Hours Course #LS1003 Approved Continuing Education for Licensed Professional Engineers EZ-pdh.com Ezekiel Enterprises, LLC 301 Mission Dr. Unit 571 New Smyrna Beach, FL 32170 800-433-1487 [email protected] Construction Surveying Curves Ezekiel Enterprises, LLC Course Description: The Construction Surveying Curves course satisfies three (3) hours of professional development. The course is designed as a distance learning course focused on the process required for a surveyor to establish curves. Objectives: The primary objective of this course is enable the student to understand practical methods to locate points along curves using variety of methods. Grading: Students must achieve a minimum score of 70% on the online quiz to pass this course. The quiz may be taken as many times as necessary to successful pass and complete the course. Ezekiel Enterprises, LLC Section I. Simple Horizontal Curves CURVE POINTS Simple The simple curve is an arc of a circle. It is the most By studying this course the surveyor learns to locate commonly used. The radius of the circle determines points using angles and distances. In construction the “sharpness” or “flatness” of the curve. The larger surveying, the surveyor must often establish the line of the radius, the “flatter” the curve. a curve for road layout or some other construction. The surveyor can establish curves of short radius, Compound usually less than one tape length, by holding one end Surveyors often have to use a compound curve because of the tape at the center of the circle and swinging the of the terrain.
    [Show full text]
  • And Are Congruent Chords, So the Corresponding Arcs RS and ST Are Congruent
    9-3 Arcs and Chords ALGEBRA Find the value of x. 3. SOLUTION: 1. In the same circle or in congruent circles, two minor SOLUTION: arcs are congruent if and only if their corresponding Arc ST is a minor arc, so m(arc ST) is equal to the chords are congruent. Since m(arc AB) = m(arc CD) measure of its related central angle or 93. = 127, arc AB arc CD and . and are congruent chords, so the corresponding arcs RS and ST are congruent. m(arc RS) = m(arc ST) and by substitution, x = 93. ANSWER: 93 ANSWER: 3 In , JK = 10 and . Find each measure. Round to the nearest hundredth. 2. SOLUTION: Since HG = 4 and FG = 4, and are 4. congruent chords and the corresponding arcs HG and FG are congruent. SOLUTION: m(arc HG) = m(arc FG) = x Radius is perpendicular to chord . So, by Arc HG, arc GF, and arc FH are adjacent arcs that Theorem 10.3, bisects arc JKL. Therefore, m(arc form the circle, so the sum of their measures is 360. JL) = m(arc LK). By substitution, m(arc JL) = or 67. ANSWER: 67 ANSWER: 70 eSolutions Manual - Powered by Cognero Page 1 9-3 Arcs and Chords 5. PQ ALGEBRA Find the value of x. SOLUTION: Draw radius and create right triangle PJQ. PM = 6 and since all radii of a circle are congruent, PJ = 6. Since the radius is perpendicular to , bisects by Theorem 10.3. So, JQ = (10) or 5. 7. Use the Pythagorean Theorem to find PQ.
    [Show full text]
  • Trigonometry and Spherical Astronomy 1. Sines and Chords
    CHAPTER TWO TRIGONOMETRY AND SPHERICAL ASTRONOMY 1. Sines and Chords In Almagest I.11 Ptolemy displayed a table of chords, the construction of which is explained in the previous chapter. The chord of a central angle α in a circle is the segment subtended by that angle α. If the radius of the circle (the “norm” of the table) is taken as 60 units, the chord can be expressed by means of the modern sine function: crd α = 120 · sin (α/2). In Ptolemy’s table (Toomer 1984, pp. 57–60), the argument, α, is given at intervals of ½° from ½° to 180°. Columns II and III display the chord, in units, minutes, and seconds of a unit, and the increase, in the same units, in crd α corresponding to an increase of one minute in α, computed by taking 1/30 of the difference between successive entries in column II (Aaboe 1964, pp. 101–125). For an insightful account on Ptolemy’s chord table, see Van Brummelen 2009, where many issues underlying the tables for trigonometry and spherical astronomy are addressed. By contrast, al-Khwārizmī’s zij originally had a table of sines for integer degrees with a norm of 150 (Neugebauer 1962a, p. 104) that has uniquely survived in manuscripts associated with the Toledan Tables (Toomer 1968, p. 27; F. S. Pedersen 2002, pp. 946–952). The corresponding table in al-Battānī’s zij displays the sine of the argu- ment at intervals of ½° with a norm of 60 (Nallino 1903–1907, 2:55– 56). This table is reproduced, essentially unchanged, in the Toledan Tables (Toomer 1968, p.
    [Show full text]
  • Notes on Curves for Railways
    NOTES ON CURVES FOR RAILWAYS BY V B SOOD PROFESSOR BRIDGES INDIAN RAILWAYS INSTITUTE OF CIVIL ENGINEERING PUNE- 411001 Notes on —Curves“ Dated 040809 1 COMMONLY USED TERMS IN THE BOOK BG Broad Gauge track, 1676 mm gauge MG Meter Gauge track, 1000 mm gauge NG Narrow Gauge track, 762 mm or 610 mm gauge G Dynamic Gauge or center to center of the running rails, 1750 mm for BG and 1080 mm for MG g Acceleration due to gravity, 9.81 m/sec2 KMPH Speed in Kilometers Per Hour m/sec Speed in metres per second m/sec2 Acceleration in metre per second square m Length or distance in metres cm Length or distance in centimetres mm Length or distance in millimetres D Degree of curve R Radius of curve Ca Actual Cant or superelevation provided Cd Cant Deficiency Cex Cant Excess Camax Maximum actual Cant or superelevation permissible Cdmax Maximum Cant Deficiency permissible Cexmax Maximum Cant Excess permissible Veq Equilibrium Speed Vg Booked speed of goods trains Vmax Maximum speed permissible on the curve BG SOD Indian Railways Schedule of Dimensions 1676 mm Gauge, Revised 2004 IR Indian Railways IRPWM Indian Railways Permanent Way Manual second reprint 2004 IRTMM Indian railways Track Machines Manual , March 2000 LWR Manual Manual of Instructions on Long Welded Rails, 1996 Notes on —Curves“ Dated 040809 2 PWI Permanent Way Inspector, Refers to Senior Section Engineer, Section Engineer or Junior Engineer looking after the Permanent Way or Track on Indian railways. The term may also include the Permanent Way Supervisor/ Gang Mate etc who might look after the maintenance work in the track.
    [Show full text]
  • 20. Geometry of the Circle (SC)
    20. GEOMETRY OF THE CIRCLE PARTS OF THE CIRCLE Segments When we speak of a circle we may be referring to the plane figure itself or the boundary of the shape, called the circumference. In solving problems involving the circle, we must be familiar with several theorems. In order to understand these theorems, we review the names given to parts of a circle. Diameter and chord The region that is encompassed between an arc and a chord is called a segment. The region between the chord and the minor arc is called the minor segment. The region between the chord and the major arc is called the major segment. If the chord is a diameter, then both segments are equal and are called semi-circles. The straight line joining any two points on the circle is called a chord. Sectors A diameter is a chord that passes through the center of the circle. It is, therefore, the longest possible chord of a circle. In the diagram, O is the center of the circle, AB is a diameter and PQ is also a chord. Arcs The region that is enclosed by any two radii and an arc is called a sector. If the region is bounded by the two radii and a minor arc, then it is called the minor sector. www.faspassmaths.comIf the region is bounded by two radii and the major arc, it is called the major sector. An arc of a circle is the part of the circumference of the circle that is cut off by a chord.
    [Show full text]
  • Effect of Vehicle Performance at High Speed and High Cant Deficiency
    Proceedings of the ASME/ASCE/IEEE 2011 Joint Rail Conference JRC2011 March 16-18, 2011, Pueblo, Colorado, USA JRC2011-56066 EXAMINATION OF VEHICLE PERFORMANCE AT HIGH SPEED AND HIGH CANT DEFICIENCY Brian Marquis Jon LeBlanc U.S. Department of Transportation, Research and U.S. Department of Transportation, Research and Innovative Technology Administration, Volpe Innovative Technology Administration, Volpe National Transportation Systems Center National Transportation Systems Center Cambridge, Massachusetts, United States Cambridge, Massachusetts, United States Ali Tajaddini U.S. Department of Transportation, Federal Rail Road Administration, Office of Research and Development, Washington D.C., United States ABSTRACT The research for this paper was part of work done for the FRA In the US, increasing passenger speeds to improve trip time to support the FRA Railroad Safety Advisory Committee usually involves increasing speeds through curves. Increasing (RSAC) Track Working Group’s Vehicle Track Interaction speeds through curves will increase the lateral force exerted on (VTI) Task Force. The mission of the VTI task force was to track during curving, thus requiring more intensive track update Parts 213 and 238 of the Code of Federal Regulations maintenance to maintain safety. These issues and other (CFR) regarding rules for high speed (above 90mph) and high performance requirements including ride quality and vehicle cant deficiency (about 5 inches) operations. The task force stability, can be addressed through careful truck design. focused on a number of issues including refinement of VTI Existing high-speed rail equipment, and in particular their safety criteria, track geometry standards, vehicle qualification bogies, are better suited to track conditions in Europe or Japan, procedures and requirements and track inspection in which premium tracks with little curvature are dedicated for requirements, all with a focus on treating the vehicle and track high-speed service.
    [Show full text]
  • Coverrailway Curves Book.Cdr
    RAILWAY CURVES March 2010 (Corrected & Reprinted : November 2018) INDIAN RAILWAYS INSTITUTE OF CIVIL ENGINEERING PUNE - 411 001 i ii Foreword to the corrected and updated version The book on Railway Curves was originally published in March 2010 by Shri V B Sood, the then professor, IRICEN and reprinted in September 2013. The book has been again now corrected and updated as per latest correction slips on various provisions of IRPWM and IRTMM by Shri V B Sood, Chief General Manager (Civil) IRSDC, Delhi, Shri R K Bajpai, Sr Professor, Track-2, and Shri Anil Choudhary, Sr Professor, Track, IRICEN. I hope that the book will be found useful by the field engineers involved in laying and maintenance of curves. Pune Ajay Goyal November 2018 Director IRICEN, Pune iii PREFACE In an attempt to reach out to all the railway engineers including supervisors, IRICEN has been endeavouring to bring out technical books and monograms. This book “Railway Curves” is an attempt in that direction. The earlier two books on this subject, viz. “Speed on Curves” and “Improving Running on Curves” were very well received and several editions of the same have been published. The “Railway Curves” compiles updated material of the above two publications and additional new topics on Setting out of Curves, Computer Program for Realignment of Curves, Curves with Obligatory Points and Turnouts on Curves, with several solved examples to make the book much more useful to the field and design engineer. It is hoped that all the P.way men will find this book a useful source of design, laying out, maintenance, upgradation of the railway curves and tackling various problems of general and specific nature.
    [Show full text]
  • Component Parts of a Permanent Way
    RAILWAY ENGINEERING Dept. of Civil Engineering - KLU COMPONENT PARTS OF A PERMANENT WAY Following are the components of a permanent way. (i) Subgrade (ii) Ballast (iii) Sleepers (iv) Rails (v) Fixture and Fastening In a permanent way, rails are joined either by welding or by using fish plates and are fixed with sleepers by using different types of fastenings. Sleepers are properly placed and packed with ballast. Ballast is placed on the prepared subgrade called formation. REQUIREMENTS OF AN IDEAL PERMANENT WAY Following are the basic requirements of a permanent way: (i) The guage should be uniform and correct. (ii) Both the rails should be at the same level in a straight track. (iii) On curves proper superelevation should be provided to the outer rail. (iv) The permanent way should be properly designed so that the load of the train is uniformly distributed over the two rails. (v) The track should have enough lateral strength. (vi) The radii and superelevation, provided on curves, should be properly designed. (vii) The track must have certain amount of elasticity. (viii) All joints, points and crossings should be properly designed. (ix) Drainage system of permanent way should be perfect. (x) All the components of permanent way should satisfy the design requirements. (xi) It should have adequate provision for easy renewals and repairs. B.G.Rahul RAILWAY ENGINEERING Dept. of Civil Engineering - KLU TYPES OF RAILS The rails used in the construction of railway track are of following types: 1. Double headed rails(D.H. Rails) 2. Bull headed rails(B.H.Rails) 3. Flat footed rails(F.F.Rails) DOUBLE HEADED RAILS The rail sections, whose foot and head are of same dimensions, are called Double headed or Dumb-bell rails.
    [Show full text]
  • Differential and Integral Calculus
    DIFFERENTIAL AND INTEGRAL CALCULUS WITH APPLICATIONS BY E. W. NICHOLS Superintendent Virginia Military Institute, and Author of Nichols's Analytic Geometry REVISED D. C. HEATH & CO., PUBLISHERS BOSTON NEW YORK CHICAGO w' ^Kt„ Copyright, 1900 and 1918, By D. C. Heath & Co. 1 a8 v m 2B 1918 ©CI.A492720 & PREFACE. This text-book is based upon the methods of " limits " and ''rates/' and is limited in its scope to the requirements in the undergraduate courses of our best universities, colleges, and technical schools. In its preparation the author has embodied the results of twenty years' experience in the class-room, ten of which have been devoted to applied mathematics and ten to pure mathematics. It has been his aim to prepare a teachable work for begimiers, removing as far as the nature of the subject would admit all obscurities and mysteries, and endeavoring by the introduction of a great variety of practical exercises to stimulate the student's interest and appetite. Among the more marked peculiarities of the work the follow- ing may be enumerated : — i. A large amount of explanation. 2. Clear and simple demonstiations of principles. 3. Geometric, mechanical, and engineering applications. 4. Historical notes at the heads of chapters giving a brief account of the discovery and development of the subject of which it treats. 5. Footnotes calling attention to topics of special historic interest. iii iv Preface 6. A chapter on Differential Equations for students in mathematical physics and for the benefit of those desiring an elementary knowledge of this interesting extension of the calculus.
    [Show full text]