A modern US switcher, an EMD SW1500.

An EMD SD39 and slug in switching service.

A switcher (the general United States usage; common British terminology is shunter, while the Pennsylvania Railroad used shifter) is a small railroad locomotive intended not for moving trains any great distance but rather for assembling a train ready for a road locomotive to take over, disassembling a train that has been brought in, and generally moving railroad cars around. They do this in classification yards. Switchers may also make short transfer runs and even be the only motive power on branch lines. Download high resolution version (2304x1728, 1060 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2304x1728, 1060 KB) Wikipedia does not have an article with this exact name. ... Union Pacific UPY 1069, a SW1500 equipped with Flexicoil trucks for higher speed service. ... Image File history File links Download high resolution version (1024x553, 309 KB)BNSF locomotive 6203, an EMD SD39 paired with a six-axle slug. ... Image File history File links Download high resolution version (1024x553, 309 KB)BNSF locomotive 6203, an EMD SD39 paired with a six-axle slug. ... An EMD SD39 is a 6-axle diesel locomotive built by General Motors Electro-Motive Division between August 1968 and May 1970. ... For other meanings, see Slug (disambiguation) Cabless slug Cabbed slug A railroad slug is an accessory to a locomotive. ... 1911 map The Pennsylvania Railroad (AAR reporting mark PRR) was an American railroad existing 1846–1968, after which it merged into Penn Central Transportation. ... Rail transport refers to the land transport of passengers and goods along railways or railroads. ... A locomotive (from lat. ... In rail transport, a train consists of a single or several connected rail vehicles that are capable of being moved together along a guideway to transport freight or passengers from one place to another along a planned route. ... A railroad car (or, more briefly, car), also known as an item of rolling stock in British parlance, is a vehicle on a railroad or railway that is not a locomotive - one that provides another purpose than purely haulage, although some types of car are powered. ... Chicago and North Western Railways Proviso Yard in Chicago, Illinois, December 1942. ... A branch line is a relatively minor railway line which branches off a more important through route. ...

The typical switcher is optimised for its job, being fairly low-powered but with a high starting tractive effort for getting heavy cars rolling quickly. Top speed is low, and no large-diameter driving wheels are to be found here. Slugs are used extensively because they allow even greater tractive effort to be applied. Nearly all slugs used for switching are of the low hood, cabless variety. Good visibility in both directions is critical, because a switcher may be running in either orientation; there's no time or space to turn a locomotive in a switcher's job. Steam switchers are either tank locomotives or have special (smaller) tenders, with such things as narrow coal bunkers and/or sloped tender decks to increase rearward visibility. Headlights, where carried, were mounted on both ends. Diesel switchers tend to have a high cab and often lower and/or narrower hoods (bonnets) containing the diesel engines, for all round visibility. Now, the vast majority of switchers are diesels, but in countries with near-total electrification, like Switzerland, there are and were electric switchers. Tractive effort is the pulling force exerted, normally by a locomotive, though the term could also be used for anything else that hauls a load. ... On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotives pistons (or turbine, in the case of a steam turbine locomotive). ... For other meanings, see Slug (disambiguation) Cabless slug Cabbed slug A railroad slug is an accessory to a locomotive. ... Great Western Railway No. ... A tank locomotive (occasionally tank engine) is a steam locomotive that carries its own fuel and water with it, instead of pulling it behind it in a tender. ... A British tender locomotive Steam locomotives often haul a tender, which is a special railroad car designed to hold the locomotives fuel and water. ... Great Western Railway No. ... The hood (US) or bonnet (UK) is the hinged cover over the engine of motor vehicles. ... East German E 18 electric locomotives of the Deutsche Reichsbahn An electric locomotive is a locomotive powered by electric motors which draws current from an overhead wire, a third rail, or an on-board storage device such as a battery or a flywheel energy storage system. ...

Switching is hard work, and heavily used switch engines wear out quickly from the abuse of constant hard contacts with cars. On the other hand, lightly used switchers last forever; there are even today a number of diesel switchers that predate the Second World War still in service. Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km into the air. ...

British and European locomotives of this type tend to be much smaller than the common size in the United States. Almost all European steam switchers were tank locomotives. A satellite composite image of Europe // Etymology Picture of Europa, carried away by bull-shaped Zeus. ... A tank locomotive (occasionally tank engine) is a steam locomotive that carries its own fuel and water with it, instead of pulling it behind it in a tender. ...

The British term, Shunter, also appears to have been adopted as a slang term for a homosexual male.

eg.

 <_d1ZZy_> TheBigBad, do you want to come round to my house this evening? <TheBigBad> Do I chuff you scouse shunter!