"Derwent" was built in 1845 for the Stockton and Darlington Railway Company and was constructed at the Hopetown Works of William and Alfred Kitching, only a few yards away from where she now stands. The Kitchins were the original founders of what is now Whessoe Ltd., Steel Fabricators. The design of "Derwent" was based on Timothy Hackworths six-coupled engine named "Royal George". The design was ideal to allow the engine to negotiate the relatively sharp curves on many colliery lines and was to set the style of a series of Stockton and Darlington engines for some years.

"Derwent" was taken out of service in 1869 and sold to Pease and Partners for their colliery lines near Crook. In 1898 the engine was presented back to the North Eastern Railway Company and placed on a plinth alongside"Locomotion" at Darlington Bank Top station. "Derwent was moved to its present home at Darlington Railway Centre and Museum in 1975 and is on loan to the museum from the National Railway Museum, York.