History of the London Underground services reached Richmond, Ealing, Hounslow and Wimbledon. As part of the project that completed the Circle line in October 1884, the District began to serve Whitechapel. As a result of the expansion, by 1898, 550 trains operated daily. Services began running to Upminster in 1902, after a link to the London, Tilbury & Southend Railway had been built. In 1869, a passage was dug through the London Clay under the Thames from Great Tower Hill to Pickle Herring Stairs near Vine Street (now Vine Lane). A circular tunnel was dug , using a wrought iron shield, a method that had
London Underground infrastructure London Underground infrastructure The infrastructure of the London Underground includes 11 lines, with 270 stations. There are two types of line on the London Underground: services that run on the sub-surface network that is just below the surface and use larger trains, and the deep-tube lines, that are for the most part self-contained and use smaller trains. Most of the lines emerge on to the surface outside the central area. The oldest trains running on the Underground were introduced in 1972. The Underground is electrified using a four-rail system, the DC traction supply being independent of the running rails. Planned