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
Line E (Buenos Aires Underground) using the two stations and their corresponding tunnels as the southern part of Line F since that line's projected trajectory in that area overlaps the former route Line E took. San José vieja was used as a set for the 1996 Argentine film Moebius and served as the fictional "Dock Sud" and "Parque" stations. Line E (Buenos Aires Underground) Line E of the Buenos Aires Underground, which runs from Bolivar to Plaza de los Virreyes, currently extending a total distance of 9.2 km, with a further extension to Retiro due to be completed in 2017. Opened in 1944, the Line