Perkins is a diesel engine working on the Ravenglass and Eskdale Railway.
NG 39 was the second Muir-Hill Fordson tractor to be bought by the railway for quarry traffic. It arrived in 1929, two years after the original tractor, and was rebuilt as a steam-outline diesel 0-4-4 in 1931 for use on passenger trains. In this guise it was named the Passenger Tractor and nicknamed Pretender. It worked through the war and the first passenger services after the end of the conflict. In 1975 the petrol engine was replaced with a Perkins P6 diesel, giving the loco a modern radiator grill at the front. In 1984, the engine was rebuilt again, however this time it lost its fake steam outline and became similar to an industrial diesel shunter. It was named Perkins in 1985 and was re-engined again in 1990. Its main use is on permanent way trains.