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
Upminster Bridge Upminster Bridge Upminster Bridge is a crossing of the River Ingrebourne carrying the A124 road between the suburbs of Hornchurch and Upminster in northeast London, England. The bridge is known to have existed since at least 1375 and the current brick bridge was opened in 1892, replacing a series of wooden bridges. It gave its name to the nearby Upminster Bridge tube station, which opened in 1934, and has also been applied to the neighbourhood around the station in the London Borough of Havering. The bridge has been alternatively known as Bridge House Bridge and Lower Bridge, with "Bridge House"