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In rail transport, distributed power (DP) refers to the physical distribution—at intermediate points throughout the length of a train—of separate motive power groups. Such 'groups' may be single units or multiple consists,〔http://railwaysafrica.com/index.php?option=com_content&task=view&id=3413&Itemid=0〕 and are remotely controlled from the leading locomotive. The concept of the distribution of motive-power was originally developed to permit the operation of longer trains where operational considerations or economics required it, however distributed power has since also been used under circumstances where it is desired to have motive-power at each end of a train simply for reasons of operational flexibility. ==Advantages and disadvantages== The greatest benefit of distributed power—and the reason for development of the original concept—is the reduction of drawgear draft forces, permitting the doubling in the size of trains without exceeding draw-gear strength, through the use of mid-train locomotives. There are also potential train handling benefits; over an undulating track profile, a skillful engineer can manipulate the relative power outputs (as well as dynamic and air brake applications) to minimize run-in and run-out of coupler slack throughout the train." Reduced draft forces along a train will reduce the lateral force between wheel and rail on curves, thus reducing fuel consumption and wear on various running-gear components as well as the potential for a 'stringline' derailment. Another benefit is quicker application of standard air brakes. With all braking control at the front on a conventional train, it can take several seconds for brake-pipe pressure changes initiated by the engineer to propagate to the rear. Under radio-controlled distributed power operation, the brakes are set at remote locomotives simultaneously with the command initiated on the lead locomotive, providing a more uniform air brake response throughout the train. The main disadvantage is the operational time needed, and track configuration required, to add and remove the mid-train locomotive consists. Secondary disadvantages are the costs associated with equipping locomotives with the extra control apparatus and the potential for the intermittent loss of the telemetry signal. This latter is known as 'Communication Interrupt' and is coped-with by fail-safe software controls. 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「distributed power」の詳細全文を読む スポンサード リンク
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