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British Rail Class 455
The British Rail Class 455 is an electric multiple unit passenger train built by BREL between 1982 and 1985. It is operated on suburban services in Greater London and Surrey by South Western Railway, as well as formerly by Southern. Description The Class 455 was originally to be classified as the Class 510, at which point they were planned as a 750 V DC version of the . However, as the chopper control system at the time was not considered robust enough for the electrically rougher third rail Southern Region, they were fitted with a GEC Traction camshaft control systems instead. The Class 510 designation was discarded in favour of Class 455. A total of 505 carriages were built by British Rail Engineering Limited's Holgate Road carriage works and together with 43 existing trailers from Class 508s, formed 137 four-car sets. The 455s allowed the and to be withdrawn, as well as allowing the Class 508s to be transferred to the Merseyside network for which they were original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South West Trains
Stagecoach South Western Trains Limited, trading as South West Trains (SWT), was an English train operating company owned by Stagecoach Group, Stagecoach, which operated the South Western franchise between February 1996 and August 2017. SWT operated the majority of commuter services from its Central London terminus at London Waterloo railway station, London Waterloo to South West London and was the key operator for outer suburban and regional services in the counties of Surrey, Hampshire and Dorset. It also provided regional services in Devon, Somerset, Berkshire, Wiltshire and on the Isle of Wight through its Island Line (train operating company), Island Line subsidiary. Unlike the majority of franchises, SWT operated without subsidy, subsidies, being a profitable concern due to the high number of commuters that regularly used its services. The area of operation was the former South Western division of Network SouthEast, and was also roughly that of the Railways Act 1921, pre- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulated-gate Bipolar Transistor
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch, which, as it was developed, came to combine high efficiency and fast switching. It consists of four alternating layers (P–N–P–N) that are controlled by a metal–oxide–semiconductor (MOS) gate structure. Although the structure of the IGBT is topologically the same as a thyristor with a "MOS" gate ( MOS-gate thyristor), the thyristor action is completely suppressed, and only the transistor action is permitted in the entire device operation range. It is used in switching power supplies in high-power applications: variable-frequency drives (VFDs), electric cars, trains, variable-speed refrigerators, lamp ballasts, arc-welding machines, induction hobs, and air conditioners. Since it is designed to turn on and off rapidly, the IGBT can synthesize complex waveforms with pulse-width modulation and low-pass filters, so it is also used in switching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Multiple Unit
An electric multiple unit or EMU is a multiple-unit train consisting of self-propelled carriages using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a number of the carriages. An EMU is usually formed of two or more semi-permanently coupled carriages, but electrically powered single-unit railcars are also generally classed as EMUs. The great majority of EMUs are passenger trains, but versions also exist for carrying mail. EMUs are popular on commuter and suburban rail networks around the world due to their fast acceleration and pollution-free operation. Being quieter than diesel multiple units (DMUs) and locomotive-hauled trains, EMUs can operate later at night and more frequently without disturbing nearby residents. In addition, tunnel design for EMU trains is simpler as no provision is needed for exhausting fumes, although retrofitting existing limited-clearance tunnels to accommodate the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tightlock Coupling
Type H Tightlock couplers are a variety of Janney coupler, typically used on North American mainline passenger rail cars. They are designed with mechanical features which reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types used by North American freight railroads. Like all Janney couplers, the Tightlock is "semi-automatic" with the couplers on cars or locomotives automatically locking when cars are pushed together. However, most tightlock couplers are not fully automatic, as workers still need to go between cars to hook up the air lines for the pneumatic brakes, and connect cables for head-end power and other communications. Also, to separate cars, a worker needs to use a lever to move the locking pin that keeps the coupler closed. In Europe, some operators experimented with making fully automatic tightlock couplers by adding integral pneumatic and electric connectors, but these connections experienced reliabi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Train Protection & Warning System
The Train Protection & Warning System (TPWS) is a train protection system used throughout the British passenger main-line railway network, and in Victoria, Australia. The British Rail Safety and Standards Board's definition is: The purpose of TPWS is to stop a train by automatically initiating a brake demand, where TPWS track equipment is fitted, if the train has: *passed a signal at danger without authority *approached a signal at danger too fast *approached a reduction in permissible speed too fast *approached buffer stops too fast. TPWS is not designed to prevent SPADs but to mitigate the consequences of a SPAD, by preventing a train that has had a SPAD from reaching a conflict point after the signal. A standard installation consists of an on-track transmitter adjacent to a signal, activated when the signal is at danger. A train that passes the signal will have its emergency brake activated. If the train is travelling at speed, this may be too late to stop it before the point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Warning System
The Automatic Warning System (AWS) was introduced in the 1950s in the United Kingdom to provide a train driver with an audible warning and visual reminder that they were approaching a distant signal at caution. Its operation was later extended to give warnings for; * A colour light signal displaying a double yellow (steady or flashing), single yellow or red aspect * A reduction in permissible speed * A temporary or emergency speed restriction * An automatic barrier crossing locally monitored (ABCL), an automatic open crossing locally monitored (AOCL), or an open crossing (OC). AWS was based on a 1930 system developed by Alfred Ernest Hudd and marketed as the "Strowger-Hudd" system. An earlier contact system, installed on the Great Western Railway since 1906 and known as automatic train control (ATC), was gradually supplanted by AWS within the Western Region of British Railways. Principles of operation Information is conveyed by magnetic fields to the moving train throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knorr-Bremse
Knorr-Bremse AG is a German manufacturer of braking systems for rail and commercial vehicles that has operated in the field for over 110 years. Other products in Group's portfolio include intelligent door systems, control components, air conditioning systems for rail vehicles, torsional vibration dampers, and transmission control systems for commercial vehicles. In 2019, the Group's workforce of over 28,000 achieved worldwide sales of EUR 6.93 billion. The Group has a presence in over 30 countries, at 100 locations. On 4 November 2020, it was announced that Knorr-Bremse AG had chosen Dr. Jan Michael Mrosik to be a member of the Executive Board and CEO. The appointment takes effect as of 1 January 2021. History Foundation Engineer Georg Knorr established ''Knorr-Bremse GmbH'' in 1905 in Boxhagen-Rummelsburg, Neue Bahnhofstraße, near Berlin (since 1920 part of Berlin-Friedrichshain). Its production of railway braking systems derived from a company ("Carpenter & Schul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regenerative Brake
Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction motor uses the vehicle's momentum to recover energy that would otherwise be lost to the brake discs as heat. This method contrasts with conventional braking systems. In those systems, the excess kinetic energy is converted to unwanted and wasted heat due to friction in the brakes, or with rheostatic brakes, where the energy is recovered by using electric motors as generators but is immediately dissipated as heat in resistors. In addition to improving the overall efficiency of the vehicle, regeneration can significantly extend the life of the braking system as the mechanical parts will not wear out quickly. General principle The most common form of regenerative brake involves an electric motor functioning as an electric generator. In elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westcode
IXYS Corporation is an American company based in Milpitas, California. IXYS focuses on power semiconductors, radio-frequency (RF) power semiconductors, and digital and analog integrated circuits (ICs). History Dr. Nathan Zommer founded IXYS Corporation in 1983 in Silicon Valley, Santa Clara, California. IXYS was originally a fabless power semiconductor device company. In 1989, IXYS provided power MOSFETs for the General Motors EV1. IXYS provided high-power IGBTs for the KTX-II high-speed train. In 2001, the company acquired the British semiconductor manufacturer Westcode. In December 2009, IXYS Corporation announced that it will buy Zilog, which is now the company's wholly owned subsidiary. In July 2013, IXYS Corporation finished acquiring Samsung Electronics' 4- and 8-bit microcontroller business, and the 4- and 8-bit microcontrollers acquired from Samsung will be offered by Zilog, Inc. In August 2017, IXYS Corporation was acquired by Littelfuse Inc in exchange for $750 mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Braking
Dynamic braking is the use of an electric traction motor as a generator when slowing a vehicle such as an electric or diesel-electric locomotive. It is termed " rheostatic" if the generated electrical power is dissipated as heat in brake grid resistors, and " regenerative" if the power is returned to the supply line. Dynamic braking reduces wear on friction-based braking components, and regeneration lowers net energy consumption. Dynamic braking may also be used on railcars with multiple units, light rail vehicles, electric trams, trolleybuses, and electric and hybrid electric automobiles. Principle of operation Converting electrical energy to the mechanical energy of a rotating shaft (electric motor) is the inverse of converting the mechanical energy of a rotating shaft to electrical energy (electric generator). Both are accomplished through the interactions of armature windings with a (relatively) moving external magnetic field, with the armature connected to an electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disc Brake
A disc brake is a type of brake that uses the calipers to squeeze pairs of pads against a disc or a "rotor" to create friction. This action slows the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into waste heat which must be dispersed. Hydraulically actuated disc brakes are the most commonly used form of brake for motor vehicles, but the principles of a disc brake are applicable to almost any rotating shaft. The components include the disc, master cylinder, and caliper (which contains a cylinder and two brake pads) on both sides of the disc. Design The development of disc-type brakes began in England in the 1890s. In 1902, the Lanchester Motor Company designed brakes that looked and operated in a similar way to a modern disc-brake system even though the disc was thin and a cable activated the brake pad. Other designs were not practical or widely available in cars for another 6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electro-pneumatic Brake System On British Railway Trains
The electro-pneumatic brake system on British mainline railway trains was introduced in 1950 and remains the primary braking system for multiple units in service today, although London Transport underground trains had been fitted with EP brakes since the 1920s. The Southern Region of British Railways operated a self-contained fleet of electric multiple units for suburban and middle-distance passenger trains. From 1950, an expansion of the fleet was undertaken and the new build adopted a braking system that was novel in the UK, the electro-pneumatic brake in which compressed air brake operation was controlled electrically by the driver. This was a considerable and successful technical advance, enabling a quicker and more sensitive response to the driver's operation of brake controls. Origins From the 1920s, the Southern Railway of the UK and its predecessor companies had adopted electrification and multiple-unit train operation as a solution for dense and intensive passenger ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
