cars between the two driving cars from unit 2006. The set was intended for use on the Oxted line, where it was hauled by diesel locomotives. The motors from former DMBS car number 10573 were removed, and the whole set was re-wired to enable the hauling diesel locomotive to provide the electric train heating. Six out of nine compartments of one of the 4-Sub Trailer Second cars (number 11485) were refitted as first class compartments, thereby making it a Trailer Composite. The set was originally numbered 900 in the old hauled carriage set number series, but this was amended in February 1966 to 701 in the new series for trailer control units. Despite this, and its designation as 7-TC (7-car Trailer Control stock), it was not a real trailer control unit in that a locomotive could not be operated remotely from the unit's driving cars. The unit was stored from December 1967 and then withdrawn in April 1969. However, while the two driving cars were scrapped the following year, all five trailers were reused in other units. Four returned to 4-SUB formations, but 11485 underwent a further conversion, this time to a 4EPB Trailer Second, and was renumbered 15084. Full details of the 7-TC formation, the origin of the individual cars and their subsequent disposal are set out in the table below: Accidents and incidents On 1 August 1962, unit No.2088 was derailed at , West Sussex when a set of points moved under it due to an electrical fault. Thirty-eight people were injured. Withdrawal After withdrawal in 1971, various 2-BIL units in company with 2-HAL units were noted at Stratford in east London destined for scrapping by Kings of Norwich, or being hauled west for scrapping in the Newport area. Preservation Only one 2-BIL unit has survived into preservation, namely number 2090, formed of carriages 10656 and 12123, which is in the care of the National Railway Museum, York. This unit is also one of only two pre-war main line EMUs in existence, which are still in original formation. The other is the Class 503, which is kept at the Locomotive Storage Ltd facility in Margate. Notes References Sources Further reading External links Southern Electric Group - Details of class designation. 2BIL 401 Train-related introductions in 1935 750 V DC multiple units