London Underground at +420 V, giving a potential difference of 630 V. On the sections of line shared with mainline trains, such as the District line from East Putney to Wimbledon and Gunnersbury to Richmond, and the Bakerloo line north of Queen's Park, the centre rail is bonded to the running rails. The average speed on the Underground is 20.5 mph. Outside the tunnels of central London, many lines' trains tend to travel at over 40 mph in the suburban and countryside areas. The Metropolitan line can reach speeds of 62 mph. The London Underground was used by 1.379 billion passengers in
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