The British Rail Class 205 (or 2H) diesel-electric multiple units were built by BR at Eastleigh from 1957 to 1962, and in service with BR and its successors for 47 years from Southern Region to the Southern franchise. They were eventually replaced by Class 171 Turbostar units.
This class of unit was built in four different batches for use on different lines. They gained the nickname 'Thumpers' after the noise they made while in motion.
The first batch of units was built in 1957 as two-car units and classified as 2H. They were built for services in Hampshire on the non-electrified routes between Portsmouth Harbour, Salisbury and Andover and between Alton, Winchester and Southampton. The 205s are synonymous with travelling away from the third-rail in rural areas of the Southern Region, South Central Division network and have a passionate following among enthusiasts.