Circle line (London Underground) and the C Stock trains have recently been replaced by new seven-car S Stock trains, in a programme completed in 2015. In 1863 the Metropolitan Railway, the world's first underground railway, opened in London between Paddington and Farringdon, connecting the Great Western Railway's relatively remote terminus at Paddington with Euston and King's Cross stations and the City, London's financial heart. In the same year a select committee report recommended an 'inner circle' of railway lines connecting the London termini that had been built or under construction. In the next year the Metropolitan District Railway (commonly known as the District Railway)
Romford–Upminster line Romford–Upminster line The Romford–Upminster line is a railway branch line in Greater London that connects , on the Great Eastern Main Line, to , on the London, Tilbury and Southend Line and London Underground. The route is in length and there is one intermediate station at . The line is part of Network Rail Strategic Route 7, SRS 07.09, and is classified as a rural line. The line is single-track throughout, electrified at 25 kV AC, has a loading gauge of W6, and a maximum speed of . As of May 2015 services are operated by London Overground, with two