Classification follows the Japanese system whereby a letter denotes the number of driving axles with a number to indicate the class, tank locomotives starting at 10 and tender locomotives at 50. Mallets are thus BB10 etc. West Sumatra locomotives were classified according to an overall Indonesian numbering system shared with Java and South Sumatra (but not North Sumatra).

I have tried to include photographs of all classes extant in West Sumatra in 1970, inevitably this means including a derelict D18 photographed in unpromising circumstances. 

In each case I have included some notes about the origins of the locomotives.

The current location of preserved examples is also given where known.