Switcher locomotive

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A switcher locomotive, also called a shunter, station pilot, or yard goat, is a locomotive dedicated to moving rail cars around yards and for short transfer runs. They don’t usually haul trains over long distances; instead they assemble trains so another locomotive can take over. Switchers often work in railyards, terminals, or on short branch lines. A road switcher is a hybrid that can both switch cars and haul trains.

Design and power
Switchers are built for shunting: they have high starting torque, but low top speeds and small driving wheels. This makes them good at getting heavy cars moving and stopping quickly. They are typically durable and long‑lasting. Most modern switchers are diesel‑electric, but some regions use electric switchers, and a few use battery power or a combination of diesel and electricity (electro‑diesel). Steam switchers are mostly out of service today. In some places, switchers may be equipped with slugs (unpowered units) to increase pulling power, or used in two‑unit “cow–calf” pairs for extra power.

Where they’re found
- In the United States, switchers are often larger and many are road switchers designed to move heavier trains on main lines when needed.
- In Britain, switchers are smaller, such as the Class 08 and Class 09 diesel‑electric 0‑6‑0 engines with about 350–400 horsepower.
- In continental Europe, light shunting is done with small two‑axle engines (Kleinlokomotive), and heavier work uses diesel‑hydraulic designs like the DB Class V 60.
- Some regions rely on electric switchers in areas with heavy electrification.

History and variations
Electric shunting played a role in some early industrial networks and on steep grades in Britain, with a few historic examples preserved today. Battery‑powered shunters have appeared in places like the Tyne and Wear Metro and in New Zealand in the 1920s. Steam switchers were once common but are now mostly retired, though a few survive in museums and on heritage railways.

Summary
Switchers are the rail world’s maneuver specialists. Their job is to move and couple cars precisely and safely, not to travel long distances. They come in various power types and sizes to fit local needs, from compact yard engines to more capable road switchers.