The Class 159 is a class of British diesel multiple-unit trains of the Sprinter family, built in 1989–1992 by BREL at the Derby Carriage and Wagon Works as Class 158. Before entering traffic, the original 22 units were modified at Rosyth Dockyard to Class 159 to operate express services from London Waterloo to Exeter and replace locomotive-hauled passenger trains. The units were originally branded by Network SouthEast as South Western Turbo.