London Underground Waterloo & City Line

London Underground Waterloo & City Line is a Transport for London operated tube line in London, England. Running between Waterloo and Bank, it is coloured turquoise on the Tube map, it is by far the shortest line on the Underground network at 2.37 km (1.47 miles), with an end-to-end journey lasting just four minutes. In absolute terms, it is the least-used Tube line, carrying just over 15 million passengers annually. It is one of just two lines on the network to run entirely below ground, the other being the Victoria line.

Also colloquially known as The Drain with no intermediate stops. Its primary traffic consists of commuters from south-west London, Surrey and Hampshire arriving at Waterloo main line station and travelling forward to the City of London financial district, and for this reason the line does not normally operate on Sundays.

The line was built by the Waterloo & City Railway Company and was opened in 1898 (at the time, Bank station was named "City"). When it opened it was the second electric underground railway in London, following the City and South London Railway (now part of the Northern line). For much of its existence, it was owned and operated by two main line rail companies, before it was nationalised into British Rail. Operations were transferred to London Underground in 1994 following a major refurbishment and replacement of rolling stock.

History
The London and South Western Railway (LSWR) reached Waterloo Bridge in 1848, serving routes from Southampton and Richmond. (The name of the terminal station was later changed to Waterloo, and this name is used in the remainder of this article.)

The location was some distance short of the principal commercial area of the City of London, and as regular business travel developed the inconvenience of the location became an issue. The LSWR had hoped to build a line eastwards to near London Bridge but the slump following the railway mania, and the high cost of building through the area, led to abandonment of the idea. When the South Eastern Railway built its extension from London Bridge to Charing Cross, a connecting railway line from it to Waterloo was built; but friction and competitive hostility between the companies frustrated beneficial use of the connection and it fell into disuse at the end of 1867.

A Waterloo Junction station (now called Waterloo East) was built on the Charing Cross line and opened in January 1869, but through ticketing was refused and the onward connection remained frustratingly unsatisfactory

Toward the end of the 1980s the 1940 rolling stock fleet was giving increasingly difficult service. The decision was taken to acquire new vehicles as an extension to a rolling stock acquisition programme on the Central line of London Transport (LT). This required implementation of fourth rail traction current system to maintain consistency with the LT fleet: a new aluminium centre current rail was provided. (The original steel positive rail was replaced by an aluminium one in 2008.) The new vehicles had passenger operated door opening buttons, which were unlikely to be required on the Waterloo & City line.

At the same time as the rolling stock project, the construction of what became the Eurostar terminal at Waterloo main line station was being planned, requiring construction over a large area on the north side of the station, and burying the Armstrong Lift. Also, the carriages of the new rolling stock were significantly longer than those of the 1940 stock and could not be accommodated on the Armstrong Lift. Since its removal, vehicles have been craned in and out of the Waterloo depot by a mobile crane positioned near Spur Road.

On 28 May 1993 all of the old rolling stock was withdrawn, the train service being suspended temporarily. A temporary bus service was run while the old rolling stock was physically removed and the new rolling stock brought in, and the track and signalling works undertaken, with staff training. The line reopened on 19 July 1993, with a peak service frequency of 3½ minutes.

Since its introduction, this stock on the Waterloo & City has diverged significantly from that used on the Central line through various modifications, including the adoption of automatic train operation on the latter, that the two are no longer interchangeable; the Waterloo & City line continues to use train stops.