Northern line

Northern line
1995 Stock leaving the tunnel north of Hendon Central
Overview
Stations	50
Colour on map	Black
Website	tfl.gov.uk
Service
Type	Rapid transit
System	London Underground
Depot(s)	Golders Green, Morden; sidings at Edgware, Colindale, Hampstead, Chalk Farm, High Barnet, East Finchley, Archway, Camden Town, Euston (Bank branch), Moorgate, Charing Cross, Kennington, Tooting Broadway[1]
Rolling stock	1995 Stock
Ridership	252.310 million passenger journeys (2011/12)[2]
History
Opened	18 December 1890 (as City and South London Railway) 28 August 1937 (renamed to Northern line)
Last extension	1926
Technical
Line length	58 km (36 mi)
Character	Deep-tube
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Operating speed	45 mph (72 km/h)[3]
Transport for London rail lines London Underground Bakerloo Central Circle District Hammersmith & City Jubilee Metropolitan Northern Piccadilly Victoria Waterloo & City Other systems Crossrail DLR London Trams London Overground TfL Rail v t e

The Northern line is a deep-level tube line on the London Underground, colored black on the Tube map. It carries more passengers than any other Underground line; 206,734,000 a year.

For most of its length it is a deep-level tube line.^{[nb 1]} The portion between Stockwell and Borough opened in 1890 and is the oldest section of deep-level tube line on the Underground network. There were about 252 million passenger journeys recorded in 2011/12 on the Northern line, making it the second-busiest on the Underground. (It was the busiest from 2003 to 2010.) It is unique in having two different routes through central London. Despite its name, it does not serve the northern-most stations on the network, though it does serve the southern-most station, Morden, as well as 16 of the system's 29 stations south of the River Thames. There are 52 stations in total on the line, of which 38 have platforms below ground.

The line has a complicated history, and the current complex arrangement of two main northern branches, two central branches and the southern route reflects its genesis as three separate railways, combined in the 1920s and 1930s. An extension in the 1920s used a route originally planned by a fourth company. Abandoned plans from the 1920s to extend the line further southwards, and then northwards in the 1930s, would have incorporated parts of the routes of two further companies. From the 1930s to the 1970s, the tracks of a seventh company were also managed as a branch of the Northern line.^{[nb 2]} An extension from Kennington to Battersea is currently under construction, which may either give the Northern line a second southern branch or may see it split into separate distinct lines with their own identities. It is coloured black on the current Tube map.

1. ↑ "Northern line facts". Transport for London. Archived from the original on 12 March 2012. Retrieved 12 March 2012.
2. ↑ "LU Performance Data Almanac". Transport for London. 2011–2012. Archived from the original on 3 August 2012. Retrieved 1 August 2012.
3. ↑ "Which London Underground line is the fastest? | CityMetric". www.citymetric.com. 18 September 2017. Retrieved 2019-02-09.^{[permanent dead link]}