A Driving Brake Standard Open or DBSO is a type of railway carriage, converted to operate as a control car (Not to be confused with DVTs as used in InterCity 225 sets). Fourteen such vehicles, numbered 9701 to 9714, were converted from Mark 2F Brake Standard Open (standard class coaches with brake van) carriages. Modifications included adding a driving cab and TDM equipment to allow a locomotive to be driven remotely.