Most of these locomotives are still in active service with Sri Lanka Railways, the national rail operator.

[1][2][3][4] The M6 locomotives were manufactured by Thyssen-Henschel in Kassel, West Germany, under licence from Electro-Motive Division of the United States.

These locomotives were originally imported for use on flat terrain, but found great success on the Main Line.

The M6 locomotives are currently used for the Colombo-Badulla Night Mail service and Main Line commuter trains.

The locomotives have found success on the Main Line owing to their Flexicoil truck (bogies) and dynamic brakes.