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A locomotive or engine is a rail transport vehicle that provides the motive power for a train. The word originates from the Latin ''loco'' – "from a place", ablative of ''locus'', "place" + Medieval Latin ''motivus'', "causing motion", and is a shortened form of the term ''locomotive engine'', first used in the early 19th century to distinguish between mobile and stationary steam engines. A locomotive has no ''payload capacity'' of its own, and its sole purpose is to move the train along the tracks.〔(【引用サイトリンク】 How Payload Works )〕 In contrast, some trains have self-propelled payload-carrying vehicles. These are not normally considered locomotives, and may be referred to as multiple units, motor coaches or railcars. The use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight (see CargoSprinter). Vehicles which provide motive power to haul an unpowered train, but are not generally considered locomotives because they have payload space or are rarely detached from their trains, are known as power cars. Traditionally, locomotives pull trains from the front. Increasingly common outside North America is push-pull operation, where one locomotive pulls the train from the front and another locomotive pushes it from behind. In this arrangement the locomotive at the rear of the train is controlled from a control cab at the front of the train. Push-pull operation is generally infeasible in North America as, even if mid-train or tail-end "helpers" are provided, the front-end might have over , net for traction, whereas the mid-train and/or tail-end "helpers" might have only , net for traction. ==Origins== Prior to locomotives, the motive force for railroads had been generated by various lower-technology methods such as human power, horse power, gravity or stationary engines that drove cable systems. The first successful locomotives were built by Cornish inventor Richard Trevithick. In 1804 his unnamed steam locomotive hauled a train along the tramway of the Penydarren ironworks, near Merthyr Tydfil in Wales. Although the locomotive hauled a train of of iron and 70 passengers in five wagons over , it was too heavy for the cast iron rails used at the time. The locomotive only ran three trips before it was abandoned. Trevithick built a series of locomotives after the Penydarren experiment, including one which ran at a colliery in Tyneside in northern England, where it was seen by the young George Stephenson.〔Ellis, p. 12〕 The first commercially successful steam locomotive was Matthew Murray's rack locomotive, ''Salamanca'', built for the narrow gauge Middleton Railway in 1812. This was followed in 1813 by the ''Puffing Billy'' built by Christopher Blackett and William Hedley for the Wylam Colliery Railway, the first successful locomotive running by adhesion only. Puffing Billy is now on display in the Science Museum in London, the oldest locomotive in existence.〔Ellis, pp. 20–22〕 In 1814 George Stephenson, inspired by the early locomotives of Trevithick and Hedley persuaded the manager of the Killingworth colliery where he worked to allow him to build a steam-powered machine. He built the ''Blücher'', one of the first successful flanged-wheel adhesion locomotives. Stephenson played a pivotal role in the development and widespread adoption of steam locomotives. His designs improved on the work of the pioneers. In 1825 he built the ''Locomotion'' for the Stockton and Darlington Railway, north east England, which became the first public steam railway. In 1829 he built ''The Rocket'' which was entered in and won the Rainhill Trials. This success led to Stephenson establishing his company as the pre-eminent builder of steam locomotives used on railways in the United Kingdom, the United States and much of Europe.〔Ellis, pp. 24–30〕 The first inter city passenger railway, Liverpool and Manchester Railway, opened in 1830, making exclusive use of steam power for both passenger and freight trains. 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「Locomotive」の詳細全文を読む スポンサード リンク
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