List of British Rail electric multiple unit classes
DC units operate off 650-850 V direct current (DC) from a third rail on the Southern Region and North London, Merseyside and Tyneside networks. The Manchester-Bury Railway line used 1,200 V DC from a side-contact third rail. The Manchester South Junction & Altrincham and "Woodhead" and initially the Great Eastern Railway routes used 1,500 V DC from overhead wires. Under the computer numbering, DC units were given a class in the range 400-599.