0-4-4-0

In the Whyte notation for the classification of steam locomotive wheel arrangement, a 0-4-4-0 is a locomotive with no leading truck, two sets of four driving wheels, and no trailing truck. Examples of this type were constructed as Shay, Heisler, Climax, Mallet, Meyer and Double Fairlie locomotives. A similar configuration was used on some Garratts, but it is referred to as 0-4-0+0-4-0.

0-4-4-0

In the Whyte notation for the classification of steam locomotive wheel arrangement, a 0-4-4-0 is a locomotive with no leading truck, two sets of four driving wheels, and no trailing truck. Examples of this type were constructed as Shay, Heisler, Climax, Mallet, Meyer and Double Fairlie locomotives. A similar configuration was used on some Garratts, but it is referred to as 0-4-0+0-4-0.