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Derailing
In rail transport, a derailment occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard. A derailment of a train can be caused by a collision with another object, an operational error (such as excessive speed through a curve), the mechanical failure of tracks (such as broken rails), or the mechanical failure of the wheels, among other causes. In emergency situations, deliberate derailment with derails or catch points is sometimes used to prevent a more serious accident. History The first recorded train derailment in history is known as the Hightstown Rail Accident in New Jersey that occurred on November 8, 1833. The train was traveling between Hightstown and Spotswood New Jersey and derailed after an axle broke on one of the carriages as a result of a journal box catching fire. The derailment resulted in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derail
A derail or derailer is a device used to prevent fouling (blocking or compromising) of a rail track (or collision with anything present on the track, such as a person, or a train) by unauthorized movements of trains or unattended rolling stock. The device works by derailing the equipment as it rolls over or through it. Although accidental derailment is damaging to equipment and track, and requires considerable time and expense to remedy, derails are used in situations where there is a risk of greater damage to equipment, injury or death if equipment is allowed to proceed past the derail point. Applications Derails may be applied: *where sidings meet main lines or other through tracks *at junctions or other crossings to protect the interlocking against unauthorized movement *temporarily at an area where crews are working on a rail line *approaching a drawbridge, dead end, or similar hazard. Design There are four basic forms of derail. Wedge The most common form is a wedg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santiago De Compostela Derailment
The Santiago de Compostela derailment occurred on 24 July 2013, when an Alvia high-speed train traveling from Madrid to Ferrol, in the north-west of Spain, derailed at high speed on a bend about outside of the railway station at Santiago de Compostela. Out of 222 people (218 passengers and 4 crew) on board, 143 were injured and 79 died."El fallecimiento de una estadounidense eleva a 79 los muertos en el accidente de Santiago" . Retrieved 28 July 2013. The train's data recorder showed t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catch Points
Catch points and trap points are types of turnout which act as railway safety devices. Both work by guiding railway carriages and trucks from a dangerous route onto a separate, safer track. Catch points are used to derail vehicles which are out of control (known as ''runaways'') on steep slopes. Trap points are used to protect main railway lines from unauthorised vehicles moving onto them from sidings or branch lines. Either of these track arrangements may lead the vehicles into a sand drag or safety siding, track arrangements which are used to safely stop them after they have left the main tracks. A derail is another device used for the same purposes as catch and trap points. Trap points ''Trap points'' are found at the exit from a siding or where a secondary track joins a main line. A facing turnout is used to prevent any unauthorised movement that may otherwise obstruct the main line. The trap points also prevent any damage that may be done by a vehicle pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polmont Rail Accident
The Polmont rail accident, also known as the Polmont rail disaster, occurred on 30July 1984 to the west of Polmont, near Falkirk, in Scotland. A westbound push-pull express train travelling from Edinburgh to Glasgow struck a cow, which had gained access to the track through a damaged fence from a field near Polmont railway station. The collision caused all six carriages and the locomotive of the train to derail, killing 13people and injuring 61others. The accident led to a debate about the safety of push-pull trains on British Rail. Background The accident happened on one of the busiest commuter lines in Scotland."13 Dead, 44 Injured After Train Hits Cow". Associated Press, New York City. 31 July 1984. At the time of the accident, British Rail passenger trains between Glasgow Queen Street and Edinburgh Waverley were operated by the push-pull technique with a single British Rail Class47 locomotive located at one end of the train at all timesSimmons, Jack; Biddle, Gordon (ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport. A bogie may remain normally attached (as on many railroad cars and semi-trailers) or be quickly detachable (as the dolly in a road train or in railway bogie exchange); it may contain a suspension within it (as most rail and trucking bogies do), or be solid and in turn be suspended (as most bogies of tracked vehicles are); it may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung (as in the landing gear of an airliner), or held in place by other means (centreless bogies). In Scotland, the term is used for a child’s (usually home-made) wooden cart. While ''bogie'' is the preferred spelling and first-listed variant in various dictionaries, bogey and bogy are also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheelset (rail Transport)
A wheelset is a pair of railroad vehicle wheels mounted rigidly on an axle such that both wheels rotate in unison. Wheelsets are often mounted in a bogie ("truck" in North America) – a pivoted frame assembly holding at least two wheelsets – at each end of the vehicle. Most modern freight cars and passenger cars have bogies each with two wheelsets, but three wheelsets (or more) are used in bogies of freight cars that carry heavy loads, and three-wheelset bogies are under some passenger cars. Four-wheeled goods wagons that were once near-universal in Europe and Great Britain and their colonies have only two wheelsets; in recent decades such vehicles have become less common as trainloads have become heavier. Conical wheel-tread Most train wheels have a conical taper of about 1 in 20 to enable the wheelset to follow curves with less chance of the wheel flanges coming in contact with the rail sides, and to reduce curve resistance. The rails general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Train Wreck, Leavick, C
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often known simply as "engines"), though some are self-propelled, such as multiple units. Passengers and cargo are carried in railroad cars, also known as wagons. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport. Trains have their roots in wagonways, which used railway tracks and were powered by horses or pulled by cables. Following the invention of the steam locomotive in the United Kingdom in 1804, trains rapidly spread around the world, allowing freight and passengers to move over land faster and cheaper than ever possible before. Rapid transit and trams were first built in the late 1800s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Embrittlement
Hydrogen embrittlement (HE), also known as hydrogen-assisted cracking or hydrogen-induced cracking (HIC), is a reduction in the ductility of a metal due to absorbed hydrogen. Hydrogen atoms are small and can permeate solid metals. Once absorbed, hydrogen lowers the stress required for cracks in the metal to initiate and propagate, resulting in embrittlement. Hydrogen embrittlement occurs most notably in steels, as well as in iron, nickel, titanium, cobalt, and their alloys. Copper, aluminium, and stainless steels are less susceptible to hydrogen embrittlement. The essential facts about the nature of hydrogen embrittlement have been known since the 19th century. Hydrogen embrittlement is maximised at around room temperature in steels, and most metals are relatively immune to hydrogen embrittlement at temperatures above 150 °C. Hydrogen embrittlement requires the presence of both atomic ("diffusible") hydrogen and a mechanical stress to induce crack growth, although tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coefficient Of Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cone
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines connecting a common point, the apex, to all of the points on a base that is in a plane that does not contain the apex. Depending on the author, the base may be restricted to be a circle, any one-dimensional quadratic form in the plane, any closed one-dimensional figure, or any of the above plus all the enclosed points. If the enclosed points are included in the base, the cone is a solid object; otherwise it is a two-dimensional object in three-dimensional space. In the case of a solid object, the boundary formed by these lines or partial lines is called the ''lateral surface''; if the lateral surface is unbounded, it is a conical surface. In the case of line segments, the cone does not extend beyond the base, while in the case of half-lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder (geometry)
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite curvilinear surface in various modern branches of geometry and topology. The shift in the basic meaning—solid versus surface (as in ball and sphere)—has created some ambiguity with terminology. The two concepts may be distinguished by referring to solid cylinders and cylindrical surfaces. In the literature the unadorned term cylinder could refer to either of these or to an even more specialized object, the ''right circular cylinder''. Types The definitions and results in this section are taken from the 1913 text ''Plane and Solid Geometry'' by George Wentworth and David Eugene Smith . A ' is a surface consisting of all the points on all the lines which are parallel to a given line and which pass through a fixed plane curv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2015 Philadelphia Train Derailment
On May 12, 2015, an Amtrak ''Northeast Regional'' train from Washington, D.C. bound for New York City derailed and wrecked on the Northeast Corridor near the Kensington neighborhood of Philadelphia, Pennsylvania. Of 238 passengers and 5 crew on board, 8 were killed and over 200 injured, 11 critically. The train was traveling at in a zone of curved tracks when it derailed. Some of the passengers had to be extricated from the wrecked cars. Many of the passengers and local residents helped first responders during the rescue operation. Five local hospitals treated the injured. The derailment disrupted train service for several days. The National Transportation Safety Board determined that the derailment was caused by the train's engineer (driver) becoming distracted by other radio transmissions and losing situational awareness, and said that it would have been prevented by positive train control, a computerized speed-limiting system that was operational elsewhere on the Northeast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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