London Underground with smaller trains that run in two circular tunnels ("tubes") with a diameter about . These lines have the exclusive use of a pair of tracks, except for the Piccadilly line, which shares track with the District line between Acton Town and Hanger Lane Junction and with the Metropolitan line between Rayners Lane and Uxbridge; and the Bakerloo line, which shares track with London Overground services north of Queen's Park. Fifty-five per cent of the system runs on the surface. There are of cut-and-cover tunnel and of tube tunnel. Many of the central London underground stations on deep-level tube routes
London Underground battery-electric locomotives Victoria line ATP equipment which was designed by Metronet BCV on behalf of Transplant, the operator of the fleet. This system was installed during 2007 at Ruislip Depot. It is compatible with the new Distance-to-Go Radio (DTG-R) ATP system which has been implemented on the Victoria line by Westinghouse Rail Systems. The locomotives are, since the start of London Underground's PPP scheme, in the ownership of TransPlant. The locomotives are usually stabled at Lillie Bridge Depot or Ruislip depot. The traditional use of these locomotives has been to haul trains using power from the rails until they reach the area