Definitions for "Shunter"
A person employed to shunt cars from one track to another.
a small locomotive used to move cars around but not to make trips
A shunting engine – a locomotive used to move wagons and coaches to make up trains, usually a small tank locomotive, and with limited coal and water capacity, because it would work in local area, though major sorting sidings and yards might require something more substantial. (For example, the Bowen Cooke 1185 0-8-2 tanks were normally employed on shunting.)
Keywords:  switchmen, switch, engine
UK] [AU] Switch engine or switchmen.
Either a dedicated vehicle used to move trailers around a depot or for short distances between sites, or the driver of such a vehicle.