PRE-1948 EX-SOUTHERN RAILWAY EMUs  in use post 1968

The London and South Western Railway (LSWR) introduced a third-rail electric traction system at 660V DC efore World War I from Waterloo to suburban destinations. The Southern Railway (SR) formed in 1923 absorbed the LSWR and its electric services and also those of  the London, Brighton and South Coast Railway (LBSCR) whose suburban overhead network they replaced by third rail. The SR systems were later upgraded to 750V and  extended throughout most South London lines out of all its London termini. Throughout the 1930s, there was much main line electrification, including the Brighton Main Line (including East, West Coastways and related routes in 1932-1933), the Portsmouth Direct Line (4 July 1937) and to Maidstone and Gillingham (1939). and  Waterloo to Alton (1937)and Reading (1939). Much of the rolling stock built by the SR continued in use until the early 1970s when it was finally replaced by new stock built in the style of other British Railways coaching stock in the 1950s, 1960s and 1970s.