The ACA class were 6000 class that were renumbered and slightly modified for WA internal workings. They were reclassed to ACA hence their very similar yet different design to the existing AC class. They do not adhere to the number by horsepower system in that they kept their original 6000 class number with the addition of the prefix ACA. They were all modified at the UGL workshops in Perth.
Drive Type: Diesel Electric - AC
Engine: GE 7FDL-16EFI
Generator: GE GMG192
Traction Motors: GE 5GEB30
Horse Power: Gross - 4,520hp
At Rail - 4,350hp
Weight: 134t
Max rated speed: 115km/h
Builders Model: C44aci