The British Rail Class 159 is a class of British diesel multiple unit trains of the Sprinter family, built in 1989–1992 by British Rail Engineering Limited (BREL)'s Derby Litchurch Lane Works as Class 158. Before entering traffic, the original 22 units were modified at Rosyth Dockyard to Class 159 to operate services from London Waterloo to Salisbury and Exeter St Davids, replacing various locomotive-hauled passenger trains. The units were originally branded by Network SouthEast as South Western Turbo.