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The Class 313 is a type of dual-voltage electric multiple unit (EMU) train built by BREL York Works between February 1976 and April 1977. They were the first second-generation EMUs to be constructed for British Rail and the first British Rail units with both a pantograph for 25 kV AC overhead lines and shoegear for 750 V DC third rail supply.〔(【引用サイトリンク】title=Class 313 )〕 They were the first units in Britain to have multi-function Tightlock couplers, allowing coupling and the connection of control electric and air supplies to be carried out from the cab. Following the withdrawal of most first-generation stock, they are the oldest EMUs in regular service on National Rail on the British mainland; in 2015 the oldest units are 39 years old. ==Description== The Class 313 was developed following extensive trials with the prototype Class 445 "PEP" built in the early 1970s. The 313 is similar to the Class 314 (Glasgow), Class 315 (Anglia suburban — east London), Class 507 (Merseyside) and Class 508 (Merseyside, formerly Southern Region). Since they were designed for use on Great Northern Suburban Inner Suburban services from to or , Letchworth Garden City which included a section of 'tube' line built to take standard size trains between and Moorgate, they are built to a slightly smaller loading gauge than conventional trains. They are standard length and width, but the roof is lower, most noticeable due to the lack of a "well" for the Stone Faiveley AMBR pantograph on the centre coach. They have to comply with regulations for underground trains, such as having doors at each end of the train for evacuation onto the tracks, and when on 750 V DC supply the traction supply for each motor coach is separate, whereas on conventional 750 V DC trains each coach in a unit is linked by a 750 V bus line. Due to this, each motor coach has shoe gear on both bogies, whereas normally it would only be on the leading bogie. They are fitted with trip-cocks that are struck by a raised train-stop arm at red signals and will apply the brakes if the train passes one. The units were originally numbered 313001-064. Each unit is formed of two outer driving motors and an intermediate trailer with a pantograph. This is a reversal of the practice started in the 1960s, where the motors and pantograph were on an intermediate vehicle, with the outer vehicles being driving trailers. Part of the reason was to simplify the equipment to allow dual-voltage operation, and to keep down weight by spreading the heavy transformer and motors between vehicles. The intermediate trailer carries the pantograph and a transformer and rectifier, which on 25 kV AC provides 750 V DC to the motor coaches, each of which has four GEC G310AZ traction motors, two per bogie. On 750 V DC each motor coach draws its supply directly through its shoe gear. 313s have series-wound DC GEC G310AZ traction motors controlled by a camshaft controlled resistance system with series and parallel motor groupings and weak field steps. Originally the heating in the motor coaches was provided by passing air over the hot traction and braking resistors in addition to conventional heaters, but this feature is no longer in use and the pneumatic dampers have been disabled. Great Northern and Southern units have been retro-fitted with cab air conditioning. 313s have rheostatic braking (which was disabled on London Overground) in addition to conventional three-step air-operated disc braking; during braking if wheelslide is detected by the WSP (WheelSlide Protection) rheostatic braking is disabled and disc-braking comes into effect. Great Northern units have sanding equipment. Unlike some other DMU/EMU classes, additional brake force is not available when the an emergency brake application is initiated and is the equivalent force of a step 3/full service application. WSP is still active when making an emergency application. In addition to the primary suspension of rubber chevron spring and oil dampers, secondary suspension is provided by two air bellows per bogie - flow into each bellow is controlled independently by a levelling valve and arm assembly that allows the suspension to inflate/deflate when the weight of the coach is increased or decreased by passenger loading. The air suspension is linked to the braking system via a Variable Load Valve (VLV), which increases air brake pressure when the coach is more heavily loaded to compensate for the additional weight. The DMS A coach has a compressor and main reservoir tank, which provide air to the unit via the main reservoir pipe for friction braking, power doors, secondary suspension and pantograph operation. The DMS B coach has an MA (Motor Alternator) set that runs on 750 V DC from the AC/DC changeover switch, whereby the transformer and rectifier provide the supply when on 25 kV working and by the shoegear directly when on 3rd rail working. The MA provides power for the following: * 415 V AC - headlight (lamp supplied through an additional transformer), traction/braking resistor cooling fan, coach heater fans (the heaters run on 750 V DC). * 240 V AC - cab heater fan, thermostat fans, appliance sockets. * 110 V DC - control supply, battery charging, train lighting, cab air conditioning, CCTV system. V vehicles are numbered as follows. *62529-62592 - DMSO *71213-71276 - PTSO *62593-62656 - BDMSO All units have standard class seating only. As built, the sliding doors were opened by the passengers. Once the driver had stopped the train and the guard had activated the master door release, a passenger could move the door handle gently sideways which operated a switch controlling the individual door opening circuit. Unfortunately many people did not wait for the guard's release and gave the handle a much harder tug, which could open the door even if the train had not stopped. Concerns over passenger safety led to the removal of the handles from March 1977 to be replaced by push-buttons which serve the same purpose as the handles. Modifications led to renumbering and reclassification. All units originally had shoebeams on the inner bogie of each motor coach, which was sufficient for third-rail duties between Drayton Park and Moorgate. Some units became surplus, and in 1987 four were transferred to the -Clacton/Walton route, which has no DC sections; they had the shoegear removed, and were renumbered from 313061-4 to 313096-9. Following an accident involving one unit at Walton on the Naze in August 1987, they were replaced by 310s in 1988. 313s had also worked on the Colchester-Walton/Clacton route between 1981 and 1983. 313001-016 had shoegear fitted to the outer bogies in addition, and were transferred to the -Watford DC route where there are long gaps in the 3rd rail. They were not renumbered but reclassified 313/1, the unmodified units becoming 313/0 - prior to this the class had no sub classes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「British Rail Class 313」の詳細全文を読む スポンサード リンク
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