A gas-turbine locomotive is a type of railway locomotive in which the prime mover is a gas turbine. Several types of gas-turbine locomotive have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels (drivers). A gas-turbine train typically consists of two power cars (one at each end of the train) and one or more intermediate passenger cars.
A gas turbine offers some advantages over a piston engine. There are few moving parts, decreasing the need for lubrication and potentially reducing maintenance costs, and the power-to-weight ratio is much higher. A turbine of a given power output is also physically smaller than an equally powerful piston engine, so that a locomotive can be extremely powerful without needing to be inordinately large.
