Dictionary of Ship Hydrodynamics

Total Page:16

File Type:pdf, Size:1020Kb

Dictionary of Ship Hydrodynamics Dictionary of Ship Hydrodynamics (Alphabetic) Version 2008 Page I INTRODUCTION rection of motion of a ship or body can be This Dictionary is intended for a broad changed or maintained by its control devices. readership including practising naval architects who wish to acquire and apply knowledge of (performance) hydrodynamics and also physicists and theo- is concerned essentially with performance in retical hydrodynamicists who wish to apply the context of power required to propel a ship at their particular knowledge to the solution of a given speed and various factors and matters ship problems. related thereto. The propelling device is gener- ally understood to be a screw propeller. Engineering, physical and nautical terms in common use have not been included when they (propulsor, propulsion) did not require special definition in the context is concerned with propeller performance and of ship hydrodynamics or when their meanings various factor related thereto together with pro- were self evident. The terms are sorted alpha- peller geometry. Except where stated, the en- betically and for each term the context of it’s tries refer generally to screw propellers. usage is given with the following signifiers: (seakeeping) (cavitation) this section covers, in general, the behaviour is defined as the process of formation of the va- and performance of a ship in a seaway includ- pour of liquid when it is subjected to reduced ing, in particular, ship motions and the sea pressure at constant ambient temperature. It is states which cause them. used in the engineering context of liquid flow around bodies generally and, in particular, (ship geometry) screw-propellers and hydrofoils. signifies ship and hull geometry generally. (general) Under this is listed a number of general terms The order of entry for each item is: title, frequently encountered in the field of naval ar- symbol, and usage, dimensions, followed by the chitecture and marine engineering. To ensure definition. In each section the titles re arranged that their general meanings are retained and that in alphabetical order. In this way, having found they are employed in the proper manner, their the item required, perusal of the section will in- definitions are given here. dicate other related items which may be of in- Also definitions or descriptions are given of a terest. For general reference, there is an overall number of liquid properties and physical con- alphabetical index of all titles and against each stants concerned of ship hydrodynamics. is given the section and page where the item is to be found. (hydrodynamics) is concerned with fundamental aspects of the The symbols given are in accordance with resistance of a ship, or body, to motion through those in the latest ITTC list which is comple- calm water without consideration on the effects mentary document. of the method of propulsion. In a number of instances, the list give alter- (manoeuvring) native symbols and these are generally included is used to define the quality which determines except where a definite preference is indicated. the ease with which the speed, attitude and di- Page 1 ITTC Dictionary, Version 2008 A Acceleration zone (cavitation) In the sequence of cavitation erosion, the zone Figure 7-1: Geometry of turning circle of the curve of weight loss versus time in which a rapid increase in weight loss occurs (the re- gion between the incubation zone and the de- celeration zone which see). Formerly called the Accumulation zone. Active rudder (propulsion, propulsor) See: Rudder, active Added mass (seakeeping) [M] The total hydrodynamic force, per unit accel- eration, exerted on a ship or other body in phase with and proportional to the acceleration. Advance angle (of propeller blade section) Added mass coefficient (seakeeping) (Aij) [-] (propulsion, propulsor) A non-dimensional coefficient expressing See: Angle, advance added mass (which see) in ith mode due to jth motion. Advance angle, effective (propulsion, propul- sor) Admiralty coefficient (performance) See: Angle, effective advance A quasi-dimensionless coefficient used for as- sessing or comparing the performa nce of ship. Advance coefficient (propulsion, propulsor) Admiralty coefficient /, where Δ is (J) [-] the displacement, V speed and P any corre- A parameter relating the speed of advance of sponding power. propeller, VA to the rate of rotation, n, given by JVnD= A , where D is the propeller diame- Advance (manoeuvring) ter. The advance coefficient may also be de- The distance by which the centre of gravity fined in term of ship speed, V, in which case it (CG) of a ship advances in the first quadrant of is given by: JVn= D. a turn. It is measured parallel to the approach V path, from the CG position at rudder execute to the CG position where the ship has changed Advance coefficient, Taylor’s (propulsion, heading by 90 degrees (See Figure 7-1). Maxi- propulsor) (δ) mum advance is the distance, measured parallel A parameter defined as: to the approach path from the CG position at ⁄ A 101.27⁄ rudder execute to the tangent to the path of the CG normal to the approach path. The first of these terms is that most commonly used. Page 2 ITTC Dictionary, Version 2008 where n is the rate of propeller rotation in revo- Advance, speed of (propulsion, propulsor, per- lution per minute, D is the propeller diameter in formance) feet, and VA is the speed of advance in knots. See: Speed of advance. Advance maximum (in stopping) (manoeu- Air content(cavitation) vring) The term used loosely to describe gas content The distance travelled by a ship, in the direction (which see) when gas content is composed of of the approach path, before coming to rest af- components of air in the liquid. ter having executed a crash-back manoeuvre from a steady, straight-line motion ahead; it is Air content ratio(cavitation) also called Headreach. (See Figure 7-2). See See: Gas content ratio. also: Transfer, maximum (in stopping). Air, still, resistance (performance) See: Resistance, wind. Figure 7-2: Crash stop manoeuvre Amidships (ship geometry) (sometimes con- tracted to midship) ( ) [-] Near the centre of ship length, specially, the section of the ship at mid length (See Figure 2-12) Amplitude (seakeeping) Extreme value of a sinusoidal quantity with re- spect to the mean value. Analysis pitch (propulsion, propulsor) See: Pitch, analysis. Angle, advance (of a propeller blade section) (propulsion, propulsor) (β) [-] The inflow angle to a propeller blade section determined by the rotative speed, ω r, the axial velocity of the fluid, VX, and the tangential ve- locity of the fluid Vθ, according to the equa tion: tan , / , r is the radius of the blade section, ω the angu- lar rate rotation and θ the angular position of Advance ratio (propulsion, propulsor) (λ) [-] the blade section. A non dimensional speed parameter relating the A simpler definition, also in use is: speed of advance, VA and the rotational tip speed, πnD, given by: tan A⁄ ⁄ ⁄ where R is the propeller radius and VA the ad- vance speed. where J is the advance coefficient, D is propel- The induced velocities are not included in the ler diameter and n its rate of rotation. determination of the advance angle (See Figure 4-3). Page 2 ITTC Dictionary, Version 2008 Angle of attack (propulsion, propulsor, ma- Angle, deadrise (ship geometry) (β) [rad] noeuvring)) (α) [-] See: Deadrise angle. The angle measured in the plane containing the lift vector and the inflow velocity vector, be- Angle of diverging waves (hydrodynamics) tween the velocity vector representing the rela- See: Wave, angle of diverging tive motion between a body and a fluid and a characteristic line or plane of the body such as Angle, downwash or sidewash (manoeuvring) the chord line of an airfoil or hydrofoil, positive See: Downwash or Sidewash angle. in the positive sense of rotation about the y- axis. (See: Axes, co-ordinate in General Sec- Angle of drift or sideslip (manoeuvring, tion). Synonymous with angle of incidence. seakeeping) See: Drift or sideslip, angle of Angle of attack, effective (propulsion, propul- Angle, effective advance (propulsion, propul- sor) (αE) [-] ∗ The angle of attack relative to the chord line in- sor) (β ) [-] cluding the induced velocities. See Figure 4-3. A propeller inflow angle defined by the equa- tion: Figure 4-3: Typical velocity diagram for a propeller tan A⁄0.7 blade section at radius r where VA is the speed of advance, n is the rate of rotation, and R is the propeller diameter. UA (r) UT (r) Angle of entrance (ship geometry) αE (r) Chord line extended See: waterline VX (r,θ) φ(r) Angle of heel or list(manoeuvring, seakeeping) αG(r,θ) β(r,θ) See: Heel or list, angle of. βI(r,θ) Angle of heel or roll, projected (manoeuvring) (ωr-Vθ ))(r, θ (or angle of attack in roll) (γ) [-] The angular displacement about the x0 axis of the principal plane of symmetry from the verti- cal, positive in the positive sense of rotation Angle of attack, geometric (propulsion, pro- about the x0 axis. (See: Axes, co-ordinate). pulsor) (αG) [-] The angle of attack relative to the chord line of Angle, hydrodynamic flow (propulsion, pro- a section neglecting the induced velocities. See pulsor) (βI) [-] Figure 4-3. The inflow angle to a propeller blade section including the axial and tangential induced ve- Angle of attack, ideal (propulsion, propulsor) locities g iven by the equation: (α ) [-] I , Angle of attack for thin airfoil or hydrofoil for A I tan which the streamlines are tangent to the mean , T line at the leading edge. This condition is usu- UA and UT are induced axial and tangential ve- ally referred to as a “shock free” entry or locities respectively (which see).
Recommended publications
  • In This Issue …
    In This Issue … INLAND SEAS®VOLUME 72 WINTER 2016 NUMBER 4 MAUMEE VALLEY COMES HOME . 290 by Christopher H. Gillcrist KEEPING IT IN TRIM: BALLAST AND GREAT LAKES SHIPPING . 292 by Matthew Daley, Grand Valley State University Jeffrey L. Ram, Wayne State University RUNNING OUT OF STEAM, NOTES AND OBSERVATIONS FROM THE SS HERBERT C. JACKSON . 319 by Patrick D. Lapinski NATIONAL RECREATION AREAS AND THE CREATION OF PICTURED ROCKS NATIONAL LAKESHORE . 344 by Kathy S. Mason BOOKS . 354 GREAT LAKES NEWS . 356 by Greg Rudnick MUSEUM COLUMN . 374 by Carrie Sowden 289 KEEPING IT IN TRIM: BALLAST AND GREAT LAKES SHIPPING by Matthew Daley, Grand Valley State University Jeffrey L. Ram, Wayne State University n the morning of July 24, 1915, hundreds of employees of the West- Oern Electric Company and their families boarded the passenger steamship Eastland for a day trip to Michigan City, Indiana. Built in 1903, this twin screw, steel hulled steamship was considered a fast boat on her regular run. Yet throughout her service life, her design revealed a series of problems with stability. Additionally, changes such as more lifeboats in the aftermath of the Titanic disaster, repositioning of engines, and alterations to her upper cabins, made these built-in issues far worse. These failings would come to a disastrous head at the dock on the Chicago River. With over 2,500 passengers aboard, the ship heeled back and forth as the chief engineer struggled to control the ship’s stability and failed. At 7:30 a.m., the Eastland heeled to port, coming to rest on the river bottom, trapping pas- sengers inside the hull and throwing many more into the river.
    [Show full text]
  • Potential for Terrorist Nuclear Attack Using Oil Tankers
    Order Code RS21997 December 7, 2004 CRS Report for Congress Received through the CRS Web Port and Maritime Security: Potential for Terrorist Nuclear Attack Using Oil Tankers Jonathan Medalia Specialist in National Defense Foreign Affairs, Defense, and Trade Division Summary While much attention has been focused on threats to maritime security posed by cargo container ships, terrorists could also attempt to use oil tankers to stage an attack. If they were able to place an atomic bomb in a tanker and detonate it in a U.S. port, they would cause massive destruction and might halt crude oil shipments worldwide for some time. Detecting a bomb in a tanker would be difficult. Congress may consider various options to address this threat. This report will be updated as needed. Introduction The terrorist attacks of September 11, 2001, heightened interest in port and maritime security.1 Much of this interest has focused on cargo container ships because of concern that terrorists could use containers to transport weapons into the United States, yet only a small fraction of the millions of cargo containers entering the country each year is inspected. Some observers fear that a container-borne atomic bomb detonated in a U.S. port could wreak economic as well as physical havoc. Robert Bonner, the head of Customs and Border Protection (CBP) within the Department of Homeland Security (DHS), has argued that such an attack would lead to a halt to container traffic worldwide for some time, bringing the world economy to its knees. Stephen Flynn, a retired Coast Guard commander and an expert on maritime security at the Council on Foreign Relations, holds a similar view.2 While container ships accounted for 30.5% of vessel calls to U.S.
    [Show full text]
  • Chapter 3 Ship Compartmentation and Watertight Integrity
    CHAPTER 3 SHIP COMPARTMENTATION AND WATERTIGHT INTEGRITY Learning Objectives: Recall the definitions of terms watertight integrity, and how they relate to each other. used to define the structure of the hull of a ship and the You will also learn about compartment checkoff lists, numbering systems used for compartment number the DC closure log, the proper care of access closures designations. Identify the different types of watertight and fittings, compartment inspections, the ship’s draft, closures and recall the inspection procedures for the and the sounding and security patrol watch. The closures. Recall the requirements for the three material information in this chapter will assist you in conditions of readiness, the purpose and use of the completing your personnel qualification standards Compartment Checkoff List (CCOL) and damage (PQS) for basic damage control. control closure log, and the procedures for checking watertight integrity. COMPARTMENTATION A ship’s ability to resist sinking after sustaining Learning Objective: Recall the definitions of terms damage depends largely on the ship’s used to define the structure of the hull of a ship and the compartmentation and watertight integrity. When numbering systems used to identify the different these features are maintained properly, fires and compartments of a ship. flooding can be isolated within a limited area. Without compartmentation or watertight integrity, a ship faces The compartmentation of a ship is a major feature almost certain doom if it is severely damaged and the of its watertight integrity. Compartmentation divides emergency damage control (DC) teams are not the interior area of a ship’s hull into smaller spaces by properly trained or equipped.
    [Show full text]
  • Pennsylvania
    Spring 1991 $1.50 Pennsylvania • The Keystone States Official Boating Magazine Viewpoint Recently we received a letter suggesting that we were being contradictory in Boat Pennsylvania. According to one reader, we suggested that boaters wear personal flota- tion devices, but that the magazine photographs don't always show their use. Obtaining photographs for a magazine can be a difficult proposition. Sometimes we stage situations and take the photographs ourselves. More often, we rely on photographs submitted by contributors. Photos that depict the general boating public often do not show people wearing PFDs simply because the incidence of wearing them is so low. If we were to say that we would only use photos that showed boaters wearing PFDs, we would have a difficult time fmding acceptable photos. Generally, we try to show people wearing PFDs in small boats in situations in which devices should obviously be worn. On large boats, people most often do not wear their PFDs. Should people wear PFDs? Statistics show that wearing a PFD can save your life. Are PFDs needed all the time? Because accidents happen when they are least expected, wearing a PFD all the time is a good idea. Practically, however, as comfortable as the newest PFDs are, they can be excruciating on a hot July day. Many boaters also want to get a little sun. We accept this and our statistics show that the chances of having an accident where a PFD would have been a factor are much lower in the summer months. Ofcourse, circumstances do exist in which wearing a PFD,even on the hottest day, is warranted.
    [Show full text]
  • 35 CFR Ch. I (7–1–98 Edition)
    § 109.5 35 CFR Ch. I (7±1±98 Edition) (b) The number of Canal deckhands not less than 100 square inches (645 to be placed on board a transiting ves- square centimeters) in areaÐpreferred sel to assist her crew in handling tow- dimensions are 12 x 9 inches (305 x 229 ing wires in the locks. millimeters)Ðand shall be capable of withstanding a strain of 100,000 pounds § 109.5 Ship's gear to be ready during (43,331 kilograms) on a towing wire transit; test. from any direction. Before beginning transit of the (e) Chocks designated as double Canal, a vessel shall have hawsers, chocks shall have a throat opening of lines and fenders ready for passing not less than 140 square inches (903 through the locks, for warping, towing, square centimeters) in areaÐpreferred or mooring as the case may be; and dimensions are 14 x 10 inches (356 x 254 shall have both anchors ready for let- millimeters)Ðand shall be capable of ting go. The Master shall assure him- withstanding a strain of 140,000 pounds self, by actual test, of the readiness of (64,000 kilograms) on the towing wires his vessel's main engines, steering from any direction. gear, engine room telegraphs, whistle, (f) Use of roller chocks is permissible rudder-angle and engine-revolution in- provided they are not less than 14.94 dicators, and anchors. During the tran- meters (49 feet) above the waterline at sit, at all times while a vessel is under- the vessel's maximum Panama Canal way or moored against the lock walls, draft and provided they are in good her deck winches, capstans, and other condition, meet all of the requirements power equipment for handling lines, as for solid chocks as specified in para- well as her mooring bitts, chocks, graphs (a), (b), (c), and (d) of this sec- cleats, hawse pipes, etc., shall be ready tion, as the case may be, and are so for handling the vessel, to the exclu- fitted that transition from the rollers sion of all other work.
    [Show full text]
  • Ship Stability
    2018-08-07 Lecture Note of Naval Architectural Calculation Ship Stability Ch. 7 Inclining Test Spring 2018 Myung-Il Roh Department of Naval Architecture and Ocean Engineering Seoul National University 1 Naval Architectural Calculation, Spring 2018, Myung-Il Roh Contents þ Ch. 1 Introduction to Ship Stability þ Ch. 2 Review of Fluid Mechanics þ Ch. 3 Transverse Stability Due to Cargo Movement þ Ch. 4 Initial Transverse Stability þ Ch. 5 Initial Longitudinal Stability þ Ch. 6 Free Surface Effect þ Ch. 7 Inclining Test þ Ch. 8 Curves of Stability and Stability Criteria þ Ch. 9 Numerical Integration Method in Naval Architecture þ Ch. 10 Hydrostatic Values and Curves þ Ch. 11 Static Equilibrium State after Flooding Due to Damage þ Ch. 12 Deterministic Damage Stability þ Ch. 13 Probabilistic Damage Stability 2 Naval Architectural Calculation, Spring 2018, Myung-Il Roh 1 2018-08-07 How can you get the value of the KG? K: Keel G: Center of gravity Ch. 7 Inclining Test 3 Naval Architectural Calculation, Spring 2018, Myung-Il Roh The Problem of Finding an Accurate Vertical Center of Gravity (KG) The problem of finding an accurate KG for a ship is a serious one for the ship’s designer. FG G ü Any difference in the weight of structural parts, equipment, or welds in different ship will produce a different KG. K There is an accurate method of finding KG for any particular ship and that is the inclining test. 4 Naval Architectural Calculation, Spring 2018, Myung-Il Roh 2 2018-08-07 Required Values to Find the KG (2/3) Heeling moment produced by total weight Righting moment produced by buoyant force Static equilibrium of moment t =F × GZ Inclining test formula r B 6 Naval Architectural Calculation, Spring 2018, Myung-Il Roh Required Values to Find the KG (1/3) GZ» GM ×sinf (at small angle f ) GM= KB +BM - KGKG The purpose of the inclining test is to determine the position of the center of mass of the ship in an accurately known condition.
    [Show full text]
  • Safe Harbor Worksheet
    Safe Harbor Worksheet Description: Why should we care about Harbors? Roughly 90% of the world's goods are transported by sea. The port of NY/NJ is the third busiest port in the U.S. and the 18th in the World. Without our ports, life as we know it would not exist, however they are often overlooked. As trade volume increases, so does the size of ships. When European explorers first visited the New York Harbor, they found an estuary with a natural depth of 17 feet. As colonies became established and trade flourished, shipping channels were needed to allow for bigger ships. By 1880, the main ship channel was dredged to a depth of 24 feet and by 1891 to a depth of 30 feet. In 1914 the Ambrose Channel became the main entrance to the port of New York and had a depth of 40 feet and 2,000 feet wide (ship design changes/technological advancements allowed for wider ships). During World War II the main channel was dredged to 45 feet deep to accommodate larger ships up to Panamax size (the largest size ship which could travel through the Panama Canal). Panamax (1916) New Panamax (2016) Tonnage: 52,500 DWT Tonnage: 120,000 DWT Length: 950 ft Length: 1,201 ft Beam: 106 ft Beam: 161 ft Height: 190 ft Height: 190 ft Draft: 39.5 ft Draft: 50 ft Capacity: 5,000 TEU Capacity: 13,000 TEU Eventually even the Panama Canal was not big enough. In 2016, an expanded Panama Canal opened to allow for significantly larger ships (see above).
    [Show full text]
  • Measurement of Fishing
    35 Rapp. P.-v. Réun. Cons. int. Explor. Mer, 168: 35-38. Janvier 1975. TONNAGE CERTIFICATE DATA AS FISHING POWER PARAMETERS F. d e B e e r Netherlands Institute for Fishery Investigations, IJmuiden, Netherlands INTRODUCTION London, June 1969 — An entirely new system of The international exchange of information about measuring the gross and net fishing vessels and the increasing scientific approach tonnage was set up called the to fisheries in general requires the use of a number of “International Convention on parameters of which there is a great variety especially Tonnage Measurement of in the field of main dimensions, coefficients, propulsion Ships, 1969” .1 data (horse power, propeller, etc.) and other partic­ ulars of fishing vessels. This variety is very often caused Every ship which has been measured and marked by different historical developments in different in accordance with the Convention concluded in Oslo, countries. 1947, is issued with a tonnage certificate called the The tonnage certificate is often used as an easy and “International Tonnage Certificate”. The tonnage of official source for parameters. However, though this a vessel consists of its gross tonnage and net tonnage. certificate is an official one and is based on Inter­ In this paper only the gross tonnage is discussed national Conventions its value for scientific purposes because net tonnage is not often used as a parameter. is questionable. The gross tonnage of a vessel, expressed in cubic meters and register tons (of 2-83 m3), is defined as the sum of all the enclosed spaces. INTERNATIONAL REGULATIONS ON TONNAGE These are: MEASUREMENT space below tonnage deck trunks International procedures for measuring the tonnage tweendeck space round houses of ships were laid down as follows : enclosed forecastle excess of hatchways bridge spaces spaces above the upper- Geneva, June 1939 - International regulations for break(s) deck included as part of tonnage measurement of ships poop the propelling machinery were issued through the League space.
    [Show full text]
  • User Manual – Tanker Rapid Response Damage
    USER MANUAL – TANKER RAPID RESPONSE DAMAGE ASSESSMENT September 2019 © 2019 American Bureau of Shipping. ALL RIGHTS RESERVED. USER MANUAL – TANKER RRDA Contents 1.1 General Information .................................................................................................. 5 1.2 Instructions for Validating Enrollment Status ........................................................... 6 1.3 Types of Analyses for Response ............................................................................... 7 1.4 Drills .......................................................................................................................... 7 1.5 Training ..................................................................................................................... 8 2.1 Activating/Notifying RRDA Team ........................................................................... 9 2.2 Time to Respond. ...................................................................................................... 9 2.3 Office Hours .............................................................................................................. 9 2.4 After Office Hours .................................................................................................. 10 2.5 Action After Voice Notification .............................................................................. 10 3.1 Information Requirements ....................................................................................... 11 3.2 Load Condition Before the Incident. ......................................................................
    [Show full text]
  • Inclining Test and Lightweight Survey V2.1
    GL Leaflet for Inclining test and Lightweight survey V2.1 Leaflet for Inclining test and Lightweight Survey Version 2.1 dated 2011-08-24 1 GL Leaflet for Inclining test and Lightweight survey V2.1 Version information Version Date Editor Items treated Approved 1.0 2005-05 Fim, TBo, Pei initial version HB 2.0 2011-04 Pei, GLe, SKl, MBst draft readings, status of vessel, FSM, tank fillings AFl 2.1 2011-08 Pei, Jasch BW shifting tanks, amount of additional masses, AFl shifting weights, editorial changes 2 GL Leaflet for Inclining test and Lightweight survey V2.1 Table of contents: 1 Inclining Test........................................................................................................................ 4 1.1 Purpose and objective..................................................................................................................... 4 1.2 Acceptance of the test..................................................................................................................... 4 1.3 Procedure of the inclining test ......................................................................................................... 5 1.3.1 Notification of the inclining test/lightweight survey.................................................................. 5 1.3.2 Condition of the vessel ........................................................................................................... 5 1.3.3 Mooring Arrangement.............................................................................................................5
    [Show full text]
  • AFRAMAX Tanker Design
    The Society of Naval Architects and Marine Engineers (SNAME) Greek Section – Technical Meeting 15. March 2012, Athens HOLISTIC SHIP DESIGN OPTIMISATION: Theory and Applications by Apostolos Papanikolaou National Technical University of Athens - NTUA Ship Design Laboratory – SDL http://www.naval.ntua.gr/sdl A. Papanikolaou HOLISTIC SHIP DESIGN OPTIMISATION 1 List of contents 1. Introduction to Holistic Ship Design Optimisation • Important Design Optimization Notions • Holistic Optimisation Methodology 2. Optimization of RoPax ships – Case study • Projects ROROPROB (2000-2003) and EPAN-MET4 (2004-2007) 3. Optimisation of High-Speed vessels • Project FLOWMART (2000-2003) 4. Holistic Optimisation of Tanker Ships – Projects SAFEDOR and BEST (2005-2011) • Multi-objective Optimization of Tanker Ships • Case study-reference ship • Alternative configurations • Discussion of results 5. Conclusions- The Way Ahead A. Papanikolaou HOLISTIC SHIP DESIGN OPTIMISATION 2 Important Design Optimization Notions (1) • Holism (from Greek όλος, meaning entire, total)-holistic The properties of a system cannot be determined or explained by looking at its component parts alone; instead of, the system as a whole determines decisively how the part components behave or perform. “The whole is more than the sum of the parts” (Aristotle Metaphysics) • Reductionism-reduction: is sometimes interpreted as the opposite of holism. “A complex system can be approached by reduction to its fundamental parts” • Holism and reductionism need, for proper account of complex systems, to be regarded as complementary approaches to system analysis. • Systemic and analytical approaches are also complementary and strongly related to holism and reductionism • Risk (financial): “A quantifiable likelihood of loss or of less-than-expected returns” • Risk (general): “A quantifiable likelihood of loss of an acceptable state or of a worse-than-expected state condition” • Safety: may be defined as “An acceptable state of risk” A.
    [Show full text]
  • Panamax - Wikipedia 4/20/20, 1018 AM
    Panamax - Wikipedia 4/20/20, 1018 AM Panamax Panamax and New Panamax (or Neopanamax) are terms for the size limits for ships travelling through the Panama Canal. General characteristics The limits and requirements are published by the Panama Canal Panamax Authority (ACP) in a publication titled "Vessel Requirements".[1] Tonnage: 52,500 DWT These requirements also describe topics like exceptional dry Length: 289.56 m (950 ft) seasonal limits, propulsion, communications, and detailed ship design. Beam: 32.31 m (106 ft) Height: 57.91 m (190 ft) The allowable size is limited by the width and length of the available lock chambers, by the depth of water in the canal, and Draft: 12.04 m (39.5 ft) by the height of the Bridge of the Americas since that bridge's Capacity: 5,000 TEU construction. These dimensions give clear parameters for ships Notes: Opened 1914 destined to traverse the Panama Canal and have influenced the design of cargo ships, naval vessels, and passenger ships. General characteristics New Panamax specifications have been in effect since the opening of Panamax the canal in 1914. In 2009 the ACP published the New Panamax Tonnage: 120,000 DWT specification[2] which came into effect when the canal's third set of locks, larger than the original two, opened on 26 June 2016. Length: 366 m (1,201 ft) Ships that do not fall within the Panamax-sizes are called post- Beam: 51.25 m (168 ft) Panamax or super-Panamax. Height: 57.91 m (190 ft) The increasing prevalence of vessels of the maximum size is a Draft: 15.2 m (50 ft) problem for the canal, as a Panamax ship is a tight fit that Capacity: 13,000 TEU requires precise control of the vessel in the locks, possibly resulting in longer lock time, and requiring that these ships Notes: Opened 2016 transit in daylight.
    [Show full text]