Nine K class were delivered in 1966/67 to operate services on the 657-kilometre (408 mi) Eastern Goldfields Railway from Perth to Kalgoorlie that was being converted to standard gauge.

It passed through five states, travelled on six railway systems and required a change of bogies at Melbourne, Port Pirie and Kalgoorlie.

[1] The Western Australian Government Railways also purchased 16 similar R class locomotives mounted on narrow gauge bogies.

[3] Four have been sold to SCT Logistics and three had gone to South Spur Rail Services by August 2000.

[7][8] The two sold to Goldsworthy Mining were transferred to BHP's Port Kembla operation in November 1992.