London Underground R Stock the Edgware Road-Wimbledon route, where shorter platforms necessitated the use of C Stock. Three vehicles have been preserved. London Underground R Stock The London Underground R Stock electric multiple units were used on London Underground's District line from 1949 to 1983. Composed of new cars and converted Q38 Stock trailers, the cars were built and converted in three batches between 1949 and 1959. The cars were driving motors (DM) or non-driving motors (NDM), there being no unpowered trailers. The second batch, introduced in 1952, was constructed from aluminium, saving weight and one train was left unpainted as an experiment. Considered
London Underground Electronic ticketing in the form of the contactless Oyster card was introduced in 2003. London Underground services on the East London line ceased in 2007 so that it could be extended and converted to London Overground operation, and in December 2009 the Circle line changed from serving a closed loop around the centre of London to a spiral also serving Hammersmith. Since September 2014, passengers have been able to use contactless cards on the Tube. Their use has grown very quickly and now over a million contactless transactions are made on the Underground every day. The Underground serves 270 stations.