The British Rail Class 306 was a type of electric multiple unit introduced in 1949. It consisted of 92 three-car trains which were used on newly electrified suburban lines between Shenfield and London Liverpool Street, Class 306 trains were built to a pre-World War II LNER design by Metro Cammell and Birmingham RCW, and were equipped with English Electric traction equipment. In the early 1960s the overhead wires were re-energised at 25,000 V alternating current and this entailed the fitting of a transformer and rectifier unit, which were located on the underframe between the bogies of the intermediate carriage. At the same time the location of the pantograph was moved to this carriage as well, the trains were then re-numbered 001-092 with the last two digits of each carriage number the same as the unit number. The Class 306 trains were withdrawn in the early 1980s, and it has been repainted in a near original green livery, albeit with a yellow warning panel on the front to comply with present-day safety regulations. The 306 unit was in store at MoD Kineton awaiting the resolving of issues such as asbestos contamination, Class 506 EMUs - similar to the Class 306 EMUs, but built for the Manchester-Sheffield-Wath electric railway Fox, Peter. British Railways Electric Multiple Units to 1975
The preserved Class 306 train (unit 017) as seen on the launch day of Network SouthEast. This view also shows the carriage which was not modified when the trains were converted from the DC to the AC power supply system.
View of the former Motor Brake Second Open (MBSO) vehicle showing the modified (raised) roofline above the cab when the pantograph was relocated to the centre carriage.
A side view of the centre carriage showing the Stone Faiveley AMBR pantograph and the guards' section below