Walkers Limited had previously supplied similar locomotives to the Emu Bay Railway (as the 11 class), Queensland Railways (as the DH class) and the New South Wales Government Railways (as the 73 class).

Two M Class were purchased for hump shunting at Forrestfield Yard in 1972.

These differed in having Caterpillar engines, were much lighter, could operate in multiple with each other and did not have cab signalling.

MA1862 remained in service with Westrail, and later Transperth as the Claisebrook Depot shunter until 2014.

[4] Media related to WAGR M class (diesel) at Wikimedia Commons