British Rail Class 308

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The British Rail Class 308 alternating current electric multiple units were built by BR at York, in three batches, from 1961-62. They were initially classified as AM8 units before the introduction of TOPS. The first batch of 33 units were built in 1961, numbered 133-165. This was later changed to Class 308/1 under the TOPS system, and units were renumbered 308133-165. These units were built to operate commuter services on the Great Eastern Main Line from London Liverpool Street to Shenfield, Witham, Colchester, Walton-on-the-Naze and Clacton. Each unit was formed of four carriages: two outer driving trailers, an intermediate trailer, and a motor coach. Electrically the Class 308 stock has the same equipment as the Class 302 stock with a few modifications, some of these are the types of overload, the use of fan cooled rectifier continued until the rectifiers were modified to 8 diode type from 1982, this modified main rectifier was also modified and used on the Class 309 stock due to the problems of fan cooled types suffering from blocked filters causing failures in traffic.