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The Electro-pneumatic brake system on British railway trains was introduced in 1950 and remains the primary braking system for multiple units in service today. 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 service requirements. The fleet prior to World War II used the two-pipe Westinghouse Air Brake system, which was more effective than the generally prevailing vacuum brake then in favour in the UK. However it had disadvantages, chiefly: * Partial release of a Westinghouse brake application was unresponsive and usually required a full release – which took a considerable time – and then a re-application. * On a long train the brake force during a brake application was not consistent along the length of the train; the response to the driver’s operation of the brake valve varied according to train length and the variation caused longitudinal surging. * Release after a full application is slow. * Response to the driver’s operation of the brake valve was inconsistent and not self-lapping (that is, the position of the brake control valve set the rate of change of brake force, not the level of the brake force). 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「Electro-pneumatic brake system on British railway trains」の詳細全文を読む スポンサード リンク
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