This locomotive, nicknamed Kerosene Castle, was powered by a gas turbine driving a DC generator feeding 4 electric traction motors producing 2,500 horsepower and capable of 90 mph. It was built by the Swiss companies Brown Boveri & Cie and Swiss Locomotive and Machine Works (SLM) at Winterthur in 1949. It provided express passenger service for the Great Western Railway out of Paddington Station in London until 1960 when it was withdrawn.