2-4-0 Definition

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 two leading wheels arranged in a leading truck, four coupled driving wheels and two trailing wheels in a trailing truck.

Under the Whyte notation system, a steam locomotive that has two leading wheels arranged in a leading truck, four coupled driving wheels and four trailing wheels in a trailing truck.