Built from 1984 to 1985 as 3 car units, they were augmented with 1977-80 trailer seconds from class 508 units. 508s had a different roof profile as can be seen from the 2 car in the unit. These units are all second class seating and work on suburban services. Top speed is 75 mph, 120 km/h and have 4 traction motor rated at a total of 740 kW, 992 hp. They pick up current via a 3rd rail at 750 V dc.
South West Trains unit 455714 at Dorking waiting to leave with the 10:49 service to London Waterloo via Epsom and Wimbledon on Tuesday June 8th, 1999. The station lampposts are painted in Connex blue, white and yellow.