The cab typically sits higher in diesel switcher designs than in others, which allows more visibility for the operator. They are usually designed to operate in either direction, allowing them to push and pull rail cars along a track and to move more freely through a rail station without the need to turn. Some older designs made use of a cow-calf engine configuration, in which two powered units were used together in order to boost each other's power and moving capacity. Most diesel switchers achieve maximum speed at or around 30 miles per hour, but this can vary slightly according to the specific design's engine size and weight.
Electric switchers are commonly used in countries like Switzerland, where the rail system is mostly powered by electricity. Electric switchers may run on power from an internal battery or a series of two or more batteries. Power may also be supplied by the rail itself, via a third-rail pickup. Battery-powered locomotives date back to the 19th Century, and the use of third-rail pickups and battery-powered switcher engines can be traced back as early as 1917, when the Lancashire & Yorkshire Railway used them to haul coal trains and rearrange idle rail cars.
Three-power switchers were used in the early part of the 20th Century. They were diesel-electric engines which could also run on batteries. A third-rail pickup was also integrated into the design, which allowed the engine to draw power from the third rail or an overhead electrical line. While the three-power engine design was initially only used on switchers, it was later integrated into passenger train engines and, still later, it was used in heavy-duty engines.
Early switchers were small tank locomotives with narrow coal burners. They were designed with sloped decks to increase operator visibility and sometimes had headlights mounted on both ends. Steam-powered switchers were almost universally replaced by diesel and electric switchers, but some designs have been modernized and retrofitted for current use.
