Circle line (London Underground) the stations are shared with one or more of the three other sub-surface lines, namely the District, Hammersmith & City and Metropolitan lines. On the Circle and Hammersmith & City lines combined, over 114 million passenger journeys were recorded in 2011/12. The first section became operational in 1863 when the Metropolitan Railway opened the world's first underground line between Paddington and with wooden carriages and steam locomotives. The same year a select committee report recommended an "inner circle" of lines connecting the London railway termini, and the Metropolitan District Railway (commonly known as the District Railway) was formed to build
Central line (London Underground) built parallel with the Great Western Railway's New North Main Line as far as Denham. To the east new tunnels would run to just beyond Stratford station, where the line would be extended over the London & North Eastern Railway suburban branch to Epping and Ongar in Essex, as well as a new underground line between Leytonstone and Newbury Park mostly under Eastern Avenue so as to serve the new suburbs of north Ilford and the Hainault Loop. Platforms at central London stations were to be lengthened to allow 8-car trains. Construction started, the tunnels through central London being expanded