A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels.
LNER Class A4 4468 Mallard is officially the fastest steam locomotive, reaching 126 mph (203 km/h) on 3 July 1938.
LNER Class A3 4472 Flying Scotsman was the first steam locomotive to officially reach 100 mph (160 km/h), on 30 November 1934.
The Salamanca locomotive
The Locomotion at Darlington Railway Centre and Museum
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight trains.
Pacific National diesel locomotives in Australia showing three body types, cab unit (front), hood unit (middle) and box cab (rear)
A Victorian Railways R class steam locomotive in Australia
A China Railways HXD1D electric locomotive in China
Wainwright SECR Class P on the Bluebell Railway, England