Vehicles are numbered as follows. 62529–62592: DMSO (Driver's cab, Motor car, Standard class, Open saloon) 71213–71276: PTSO (Pantograph, Trailer car, Standard class, Open saloon) 62593–62656: BDMSO (Battery for auxiliaries, Driver's cab, Motor car, Standard class, Open saloon) All units have standard class seating only. As built, the sliding doors were opened by the passengers. Once the driver had stopped the train and the guard had activated the master door release, a passenger could move the door handle gently sideways which operated a switch controlling the individual door opening circuit. Many people did not wait for the guard's release and gave the handle a much harder tug, which could open the door even if the train had not stopped. Concerns over passenger safety led to the handles being replaced by push-buttons from March 1977. Modifications led to renumbering and reclassification. All units originally had shoebeams on the inner bogie of each motor coach, which was sufficient for third-rail duties between Drayton Park and Moorgate. Some units became surplus, and in 1987 four were transferred to the Clacton/Walton route, which has no DC sections; they had the shoegear removed, and were renumbered from 313061–313064 to 313096–313099. Following an accident involving one unit at Walton-on-the-Naze in August 1987, they were replaced by units in 1988. Units 313001–313016 had shoegear fitted to the outer bogies in addition, and were transferred to the Watford DC route where there are long gaps in the third rail. They were renumbered into a new 313/1 subclass, leaving the unmodified units in subclass 313/0. Following the privatisation of British Rail, ownership of the Class 313 fleet passed to leasing company Eversholt Rail Group. In June 2012 Eversholt sold twenty units (313121 and the nineteen 313/2 units) to newly formed lessor Beacon Rail. Operations Current Southern (Govia Thameslink Railway) Nineteen 313s displaced by Capitalstars on London Overground have been transferred to Southern, replacing the newer Class 377/3 Electrostars on East and West Coastway services from . They primarily operate local services from Brighton to , , , and Seaford. In addition, they work the to and services. These units were repainted at Wolverton Works and renumbered from 313/1 into a new 313/2 subclass. The full refurbishment began in June 2010 at Wabtec Doncaster and included new flooring and carpet, new seating, improved space for cycles and passengers in wheelchairs, and the fitting of a Passenger Information System. Additional modifications were