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Derailments
In rail transport, a derailment is a type of train wreck that 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 8 November 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 fi ... [...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 the 238 passengers and 5 crew on board, 8 were killed and over 200 were injured, with 11 critically so. 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 Situation awareness, situational awareness, and said that it would have been prevented by positive train control, a computerized speed-limiting system that was o ... [...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 travelling from Madrid to Ferrol, Galicia, Ferrol, in the north-west of Spain, Derailment, derailed at high speed on a bend about outside of the Santiago de Compostela railway station, railway station at Santiago de Compostela. Of the 178 people injured, the provisional number of deaths in hospital had reached 79 by the following 28 July. Spanish Government's Ministry of Public Works Commission for Railways Accidents Investigation – accident final report {{Railway accidents and incidents in Spain 2013 in Galicia (Spain) 2010s disasters in Spain Derailments in Spain July 2013 in Europe Railway accidents in 2013 Santiago de Compostela, Derailment ... [...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, causing all six carriages and the locomotive of the train to derail. 13people were killed and 61others were injured, 17 of them seriously. 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, J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hightstown Rail Accident
The Hightstown rail accident occurred on the Camden and Amboy Railroad between Hightstown, New Jersey and Spotswood on November 8, 1833, just two months after horses were replaced by steam locomotives on the line. It is the earliest recorded train accident involving the death of passengers in America. The train had been travelling from South Amboy to Bordentown at a speed of , when, despite having stopped "to oil the wheels" and slowing to , a journal box overheated (a condition known as hot box) and caught fire, causing an axle to break on one of the carriages, derailing and overturning it. All but one of the 24 passengers it carried were injured; one was killed outright and another died later from his injuries. Among the injured was Cornelius Vanderbilt, who broke a leg and vowed never to travel by train again, although he later broke his vow and eventually became a railway magnate, owning the New York Central Railroad, among others. Another passenger was Congressman and for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Track Gauge
In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have Wheelset (rail transport), wheelsets that are compatible with the track gauge. Since many different track gauges exist worldwide, gauge differences often present a barrier to wider operation on railway networks. The term derives from the metal bar, or gauge, that is used to ensure the distance between the rails is correct. Railways also deploy two other gauges to ensure compliance with a required standard. A ''loading gauge'' is a two-dimensional profile that encompasses a cross-section of the track, a rail vehicle and a maximum-sized load: all rail vehicles and their loads must be contained in the corresponding envelope. A ''structure gauge'' specifies the outline into which structures (bridges, platforms, lineside equipment etc.) must not encroach. Uses of the term The most common use of the term "track gauge" refers to the transverse distance be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estray
Estray, in common law, is any domestic animal found wandering at large or lost, particularly if its owner is unknown. In most cases, this implies domesticated animals rather than pets. Under early English common law, estrays were forfeited to the king or lord of the manor; under modern statutes, provision is made for taking up stray animals and acquiring either title to them or a lien for the expenses incurred in keeping them. A person taking up an estray has a qualified ownership in it, which becomes absolute if the owner fails to claim the animal within the statutory time limit. Whether the animal escaped through the owner's negligence or through the wrongful act of a third person is immaterial. If the owner reclaims the estray, they are liable for reasonable costs of its upkeep. The use of an estray during the period of qualified ownership, other than for its own preservation or for the benefit of the owner, is not authorized. Some statutes limit the right to take up estrays to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harmonic Oscillation
In classical mechanics, a harmonic oscillator is a system that, when displaced from its equilibrium position, experiences a restoring force ''F'' proportional to the displacement ''x'': \vec F = -k \vec x, where ''k'' is a positive constant. The harmonic oscillator model is important in physics, because any mass subject to a force in stable equilibrium acts as a harmonic oscillator for small vibrations. Harmonic oscillators occur widely in nature and are exploited in many manmade devices, such as clocks and radio circuits. If ''F'' is the only force acting on the system, the system is called a simple harmonic oscillator, and it undergoes simple harmonic motion: sinusoidal oscillations about the equilibrium point, with a constant amplitude and a constant frequency (which does not depend on the amplitude). If a frictional force ( damping) proportional to the velocity is also present, the harmonic oscillator is described as a damped oscillator. Depending on the friction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonance
Resonance is a phenomenon that occurs when an object or system is subjected to an external force or vibration whose frequency matches a resonant frequency (or resonance frequency) of the system, defined as a frequency that generates a maximum amplitude response in the system. When this happens, the object or system absorbs energy from the external force and starts vibrating with a larger amplitude. Resonance can occur in various systems, such as mechanical, electrical, or acoustic systems, and it is often desirable in certain applications, such as musical instruments or radio receivers. However, resonance can also be detrimental, leading to excessive vibrations or even structural failure in some cases. All systems, including molecular systems and particles, tend to vibrate at a natural frequency depending upon their structure; when there is very little damping this frequency is approximately equal to, but slightly above, the resonant frequency. When an Oscillation, oscillat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bogie
A bogie ( ) (or truck in North American English) comprises two or more Wheelset (rail transport), wheelsets (two Railroad wheel, wheels on an axle), in a frame, attached under a vehicle by a pivot. 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 for a dolly (trailer), dolly in a road train or in railway bogie exchange). It may include Suspension (vehicle), suspension components within it (as most rail and trucking bogies do), or be solid and in turn be suspended (as are most bogies of continuous track, tracked vehicles). 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). Although ''bogie'' is the preferred spelling and first-listed variant in various dictionaries, bogey and bogy are also used. Rail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheelset (rail Transport)
A wheelset is a pair of railroad car, railroad vehicle Train wheel, wheels mounted rigidly on an Axle#Vehicle axles, axle. Wheelsets are often mounted in a bogie ("List of railroad truck parts, truck" in North America) – a pivoted frame assembly holding at least two wheelsets – at each end of the vehicle. Most modern goods wagon, freight cars and Railroad car#Passenger cars, 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 cone (mathematics), conical taper of about 1 in 20 to enable the wheelset to follow Civil engineering#Surveying, curves with less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crack Propagation
Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material's resistance to fracture. Theoretically, the stress ahead of a sharp crack tip becomes infinite and cannot be used to describe the state around a crack. Fracture mechanics is used to characterise the loads on a crack, typically using a single parameter to describe the complete loading state at the crack tip. A number of different parameters have been developed. When the plastic zone at the tip of the crack is small relative to the crack length the stress state at the crack tip is the result of Elasticity (physics), elastic forces within the material and is termed linear elastic fracture mechanics (LEFM) and can be characterised using the stress intensity factor K. Although the load on a crack can be arbitrary, i ... [...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 Permeation, permeate solid metals. Once absorbed, hydrogen lowers the Stress (mechanics), stress required for cracks in the metal to initiate and propagate, resulting in embrittlement. Hydrogen embrittlement occurs 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 Stress (mechanics), mechanical stress to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
