Locomotives and train sets of Sri Lanka Railways consist mostly of diesel locomotives and multiple units. Steam locomotives are no longer used, except on heritage trains, such as the Viceroy Special. The first locomotives pulled trains on the original segment of the Main Line, on 54 kilometres (34 miles) connecting Colombo and Ambepussa. In 1953, Sri Lanka Railways enhanced its service to more power with diesel locomotives. Since then, various types of diesel locomotives were added to the service.