Circle line (London Underground) with the other London Underground sub-surface lines: the Hammersmith & City line from Hammersmith to just before Aldgate; the Metropolitan line from Baker Street to Aldgate; and the District line from Tower Hill station to Edgware Road station. The line is electrified with a four-rail DC system: a central conductor rail is energised at and a rail outside the running rail at , giving a potential difference of . The running rails are not electrified. Much of the double track railway from the Hammersmith terminus to Westbourne Park station is on a high brick viaduct. East of Westbourne Park the
London Underground in popular culture London Underground in popular culture The London Underground has long provided inspiration in various areas of popular culture. Filming is now managed all over the system but most commonly takes place at stations like Aldwych (a disused tube station), formerly on the Piccadilly line, or the non-operational Jubilee line complex in Charing Cross. The Waterloo & City line has occasionally been used for filming as it is closed on Sundays. The London Underground Film Office handles over 200 requests a month. Although not "filmed" as such on the Underground, there have been two animated children's television series set on and