plural of 4-8-4+4-8-4

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

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 4-4-6-4

plural of 6-4-4-6

plural of 4-6-4-4

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

Under the Whyte notation system, an articulated locomotive with four leading wheels on a leading truck, two sets of six driving wheels, and four trailing wheels on a trailing truck.

Under the Whyte notation system, a Mallet-type locomotive with four leading wheels on a leading truck, two sets of eight driving wheels, and four trailing wheels on a trailing truck.

Under the Whyte notation system, a Mallet-type locomotive with two leading wheels on a leading truck, two sets of four driving wheels, and two trailing wheels on a trailing truck.