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
Attacks on the London Underground Attacks on the London Underground This is a list of deliberate attacks on the infrastructure, staff or passengers of the London Underground that have caused considerable damage, injury or death. On 30 October 1883, two bombs planted as part of the Fenian dynamite campaign exploded on the "Inner Circle". The first bomb, planted on a train, exploded near Paddington (Praed Street) station damaging the train it was on and a passing train along with part of the station and the signal box. Sixty-two passengers were injured. At the same time, the second bomb exploded in the tunnel between Charing Cross