Under the Whyte notation system, a steam locomotive that is articulated in three parts, with a boiler mounted on the centre frame, and two steam engines mounted on separate frames, one on each end of the boiler, and each having an 0-4-0 wheel configuration.

Under the Whyte notation system, the simplest form of steam locomotive, with two axles and four driving wheels, and no leading wheels or trailing wheels.

Under the Whyte notation system, a steam locomotive that has two leading wheels followed by two sets of coupled driving wheels, and no trailing wheels.

Under the Whyte notation system, a steam locomotive that has four leading wheels on a leading truck followed by two sets of coupled driving wheels, and no trailing wheels.

Under the Whyte notation system, a Mallet-type locomotive with no leading truck, two sets of four driving wheels, and no trailing truck.

plural of 0-4-0+0-4-0

plural of 0-4-0

plural of 0-4-4-0

plural of 2-4-0

plural of 4-4-0