Sri Lanka Railways had a fleet of 25 of these Class M1 locomotives which began introduction in 1953 and were removed from service from 1983.

Specifications were for 25 locomotives with 750 hp (559 kW) power at the wheel, available from 12 mph (19 km/h) upwards, and up to an altitude of 6,200 ft (1,900 m).

Several firms tendered for the contact; American suppliers were unable to enter a competitive bid due to the devaluation of both the rupee and British pound.

During testing engine overheating was found to be a serious problem on the steeply graded and curving mainline.

[9] The remaining twenty locomotives, with modifications required to resolve the issues found during testing were delivered from May 1954, at a rate of approximately 1 per month.