The English Electric Type 3 locomotives (later known as the Class 37) were commissioned as part of the 1955 British Railways modernisation plan to replace the steam fleet with new diesels.

Over 300 were built by English Electric’s Vulcan Foundry at Newton-le-Willows and at Robert Stephenson and Hawthorn in Darlington.

D6737 is one of the batch built at Vulcan Foundry in 1962 was sent new to Hull Dairycoates. After service on passenger duties in the north of England, D6737, in common with many members of the class, found its way to BR Eastern Region in the 1970s and early 1980s working services on the Great Eastern main line from London Liverpool Street into East Anglia. It was renumbered 37 037 in 1974.

In the mid 1980s, the loco moved north again to Motherwell, where it was named Gartcosh in 1986, losing the name in 1992. In 1993, it came south, this time to Bristol Bath Road where it was used on freight duties down as far south west as Cornwall on china clay trains.

In 1999, it moved to France for a year and was finally withdrawn in 2003 and purchased by the Harry Needle Railroad Company from whom the Devon Diesel Society bought it at the beginning of 2004. After restoration at Barrow Hill, D6737 arrived at Buckfastleigh in July 2004.