Buff Strength
Buff strength is a design term used in the certification of passenger railroad cars. It refers to the required resistance to deformation or permanent damage due to loads applied at the car's ends, either from push-or-pull loads on the Buffer (rail transport), buffer, Janney coupler or when rolling at slow speed into a fixed barrier such as a buffer stop. United States Buff strength requirements grew out of best-practice design standards during the latter part of the nineteenth century. By the twentieth century, a design limit of was required by federal approval agencies. This was upped to for certain categories in 1945. Federal requirements for buff strength were set in 1999 at for all passenger-carrying units, unless reduced by waivers or special order. The Federal Static and Strength Regulation (49 Code of Federal Regulations § 238.203) requires that a passenger rail car be able to support a longitudinal static compressive load of without permanent deformation. There are o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Buffer (rail Transport)
A buffer is a part of the buffers-and-chain coupling system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles to one another. Description Fitted at the ends of the vehicle frames on the buffer beam, one at each corner, the buffers are projecting, shock-absorbing pads which, when vehicles are coupled, are brought into contact with those on the next vehicle. The buffer itself comprises the buffer plates which take the impact. The draw chain used between each pair of vehicles includes a screw which is tightened after coupling to shorten the chain and keep the buffers pressed together. Such is known as a 'screw coupling'. Historically, coupling chains were no more than that, a short length of heavy chain (typically three links long) with no adjustment. These would result in a 'loose-coupled train' in which the buffers of adjacent vehicles would only touch when the coupling chain was fully slack, such as when being pus ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Janney Coupler
Janney couplers are a semi-automatic form of railway coupling that allow rail cars and locomotives to be securely linked together without rail workers having to get between the vehicles. They are also known as American, AAR, APT, ARA, MCB, knuckle, Buckeye, tightlock (in the UK), Henricot (in Belgium) or Centre Buffer Couplers. Background Janney couplers were first patented in 1873 by Eli H. Janney (). Andrew Jackson Beard was amongst various inventors that made a multitude of improvements to the knuckle coupler; Beard's patents were granted 23 November 1897, which then sold for approximately $50,000, and granted 16 May 1899. In the UK, several versions of Janney couplers are fitted to a limited number of coaches, multiple units, wagons and locomotives. Janney Type E, Type F Interlock, and Type H tightlock couplings are compatible subtypes, each intended for specific rail car types. Prior to the formation of the Association of American Railroads (AAR) these were known as ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Buffer Stop
A buffer stop, bumper, bumping post, bumper block or stopblock (US), is a device to prevent railway vehicles from going past the end of a physical section of track. The design of the buffer stop is dependent, in part, on the kind of couplings that the railway uses, since the coupling gear is the first part of the vehicle that the buffer stop touches. The term "buffer stop" is of British origin, since railways in Great Britain principally use buffer-and-screw couplings between vehicles. Types Several different types of buffer stop have been developed. They differ depending on the type of coupler used and on the intended application. * Buffer stops with anticlimbers. These are particularly important for passenger railway applications, because the anticlimbers reduce the likelihood of telescoping of the railroad cars during a head-on impact. * Buffer stops for a knuckle coupler or an SA3 coupler (centrally positioned between the two rails) * Buffer stops with traditional " ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Compressive Strength
In mechanics, compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size (as opposed to tensile strength which withstands loads tending to elongate). In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently. Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load. Compressive strength is a key value for design of structures. Compressive strength is often measured on a universal testing machine. Measurements of compressive strength are affected by the specific test method and conditions of measurement. Compressive strengths are usually reported in relationship to a specific tec ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Container Compression Test
The container compression test measures the compressive strength of packages such as boxes, drums, and cans. It usually provides a plot of deformation vs compressive force. It is commonly used to evaluate shipping containers made of corrugated fiberboard as well as wooden boxes and crates. Industrial and consumer packages other than boxes can also be subjected to compression testing: drum, pail, bottle, tub etc. Package components are also evaluated for compression resistance. It is usually a laboratory test involving a special machine, a compression tester, to apply controlled compression on a test specimen. A universal testing machine is sometimes configured to perform a package compression test. Compression testing can also involve a superimposed ''dead load'' to a test package. Test procedures A common method of conducting the test, as described in several published standard test methods, is to compress a box at a constant rate of 1/2 inch (12.5 mm) per minu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. Crashworthiness may be assessed either prospectively, using computer models (e.g., LS-DYNA, PAM-CRASH, MSC Dytran, MADYMO) or experiments, or retrospectively by analyzing crash outcomes. Several criteria are used to assess crashworthiness prospectively, including the deformation patterns of the vehicle structure, the acceleration experienced by the vehicle during an impact, and the probability of injury predicted by human body models. Injury probability is defined using criteria, which are mechanical parameters (e.g., force, acceleration, or deformation) that correlate with injury risk. A common injury criterion is the head impact criterion (HIC). Crashworthiness is asse ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Deformation (engineering)
In engineering, deformation refers to the change in size or shape of an object. ''Displacements'' are the ''absolute'' change in position of a point on the object. Deflection is the relative change in external displacements on an object. Strain is the ''relative'' internal change in shape of an infinitesimally small cube of material and can be expressed as a non-dimensional change in length or angle of distortion of the cube. Strains are related to the forces acting on the cube, which are known as stress, by a stress-strain curve. The relationship between stress and strain is generally linear and reversible up until the yield point and the deformation is elastic. The linear relationship for a material is known as Young's modulus. Above the yield point, some degree of permanent distortion remains after unloading and is termed plastic deformation. The determination of the stress and strain throughout a solid object is given by the field of strength of materials and for a structure ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Headstock (rolling Stock)
A headstock of a Railroad car, rail vehicle is a transverse structural member located at the extreme end of the vehicle's underframe. The headstock supports the railway coupling, coupling at that end of the vehicle, and may also support Buffer (rail transport), buffers, in which case it may also be known as a buffer beam. The headstocks form part of the underframe of a locomotive or a railroad car. The headstocks of locomotives, railcars and Control car (rail), cabcars also support Locomotive headlamp, headlamps and the Hose (tubing), hoses for Railway air brake, air brakes, vacuum brakes as well as the Electrical cable, cables for Push–pull train, train control and head end power. Length over headstocks A commonly used measurement relating to a rail vehicle is its length over headstocks, which is the length of the vehicle excluding its Railway coupling, couplings or Buffer (rail transport), buffers (if any). Alternative expressions for length over headstocks are length ove ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Railworthiness
Railworthiness South African Qualifications Authority (SAQA). (visited on April 03, 2011) is the property or ability of a , , , or any kind of [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |