Northern line: Difference between revisions

Latest revision as of 08:35, 15 November 2025

Template:Short description Script error: No such module "about". Template:Use dmy dates Template:Infobox rail line

The Northern line is a London Underground line that runs between North London and South London. It is printed in black on the Tube map. It carries more passengers per year than any other Underground lineTemplate:Sndaround 340Template:Nbspmillion in 2019Template:Sndmaking it the busiest tube line in London. The Northern line is unique on the network in having two routes through Central London, two northern branches and two southern branches. Despite its name, it does not serve the northernmost stations on the Underground, though it does serve the southernmost station at Morden, the terminus of one of the two southern branches.

The line's northern termini, all in the London Borough of Barnet, are at Template:Lus and Template:Lus; Template:Lus is the terminus of a single-station branch line off the High Barnet branch. The two main northern branches run south to join at Template:Lus where two routes, one via Template:Lus in the West End and the other via Template:Lus in the City, continue and then join at Template:Lus in Southwark. At Kennington the line again divides into two branches, one to each of the southern termini – at Template:Lus, in the borough of Merton, and at Template:Lus in Wandsworth.

For most of its length the Northern line is a deep tube line.Template:Efn The portion between Template:Lus and Template:Lus opened in 1890 and is the oldest section of deep-level tube line on the network. Nearly 340 million passenger journeys were recorded in 2019 on the Northern line, making it the busiest on the Underground, although this is distorted due to having two branches within Central London, both of which are less busy than the core sections of other lines.^[1] Despite the line's name, it has 18 of the system's 31 stations south of the River Thames. There are 52 stations in total on the line, of which 38 have platforms below ground.

The line's structure of two northern branches (one with a further short branch), two central branches, and two southern branches reflects its complicated history. The core of the line, including the two central branches and the beginnings of the two northern branches, was constructed by two companies, the City and South London Railway and the Charing Cross, Euston and Hampstead Railway, in the 1890s and 1900s. The companies came under the same ownership in 1913, and were physically connected and operationally merged in the 1920s, while at the same time extensions to Edgware and Morden were completed. In the 1930s and 1940s the Northern line took over and electrified the London and North Eastern Railway branches to Mill Hill East and High Barnet. This was the final extension of the line for eight decades, though between the 1930s and 1970s the Northern City Line was branded and operated as part of the Northern line despite being disconnected from the rest of the line. The most recent extension, a second southern branch from Kennington to Battersea, opened on 20 September 2021. There are proposals to split the line into two lines. Template:TOC limit

History

Template:More citations needed

Formation

Template:Broader

File:Electric railway train.jpg

City & South London Railway train, 1890

The core of the Northern line evolved from two railway companies: the City & South London Railway (C&SLR) and the Charing Cross, Euston & Hampstead Railway (CCE&HR).

The C&SLR was London's first electric hauled deep-level tube railway. It was built under the supervision of James Henry Greathead, who had been responsible for the Tower Subway.Template:Sfn It was the first of the Underground's lines to be constructed by boring deep below the surface and the first to be operated by electric traction.Template:Sfn The railway opened in November 1890 from Stockwell to a now-disused station at King William Street.Template:Sfn This was inconveniently placed and unable to cope with the company's traffic so in 1900 a new route to Moorgate via Bank was opened.Template:Sfn By 1907, the C&SLR had been further extended at both ends to run from Clapham Common to Euston.Template:Sfn

File:Formation of the Northern Line small.png

Formation of the Northern line up to the 1920s

The CCE&HR, commonly known as the "Hampstead Tube", was opened in 1907 and ran from Strand (nowadays Charing Cross) via Euston to Camden Town with branches splitting to Golders Green and Highgate (nowadays Archway).Template:Sfn Template:Sfn It was extended south by one stop to Charing Cross (nowadays Embankment) in 1914 to form an interchange with the Bakerloo and District lines.Template:Sfn Template:Sfn In 1913, the Underground Electric Railways Company of London (UERL), owner of the CCE&HR, took over the C&SLR although they remained separate companies for some time.Template:Sfn

Integration

During the early 1920s a series of works were carried out to connect the C&SLR and CCE&HR tunnels to enable an integrated service to be operated. The first of these new tunnels between the C&SLR's Euston and CCE&HR's Camden Town stations had originally been planned in 1912 but was delayed by the First World War.^[2]Template:Sfn Construction began in 1922 and this first tunnel opened in 1924.Template:Sfn Template:Sfn The second connection linking the CCE&HR's Embankment and C&SLR's Kennington stations opened in 1926.Template:Sfn Template:Sfn It provided a new intermediate station at Waterloo to connect to the main line station. The smaller diameter tunnels of the C&SLR were also enlarged to match the standard diameter of the CCE&HR and other deep tube lines.Template:Sfn In conjunction with the works to integrate the two lines, two major extensions were undertaken: northwards to Edgware in Middlesex and southwards to Morden in Surrey.

The Edgware extension used plans dating back to 1901 for the Edgware and Hampstead Railway^[3] which the UERL's subsidiary, the London Electric Railway, had taken over in 1912.Template:Sfn It extended the CCE&HR line from its terminus at Golders Green to Hendon Central in 1923 and to Edgware in 1924.Template:Sfn Template:Sfn The line crossed open countryside and ran mostly on viaduct from Golders Green to Brent and then on the surface, apart from a short tunnel north of Hendon Central.Template:Sfn Five new stations were built to pavilion-style designs by Stanley Heaps, stimulating the rapid northward expansion of suburban developments in the following years.Template:Sfn

The engineering of the Morden extension of the C&SLR from Clapham Common to Morden was more demanding, running in tunnel to Morden station which was then constructed in a cutting and the line continued a bit beyond to the depot. The extension was initially planned to continue to Sutton^[4] over part of the route of the unbuilt Wimbledon and Sutton Railway (in which the UERL held a stake) but agreements were made with Southern Railway (SR) to end the extension at Morden, the SR building a surface line from Wimbledon to Sutton in the 1930s via South Merton and St. Helier.Template:Efn The tube extension itself opened in 1926 with seven new stations all designed by Charles Holden in a modern style.

Owing to the complicated nature of the resulting line, it became known as the Morden–Edgware line, although a number of alternative portmanteau names were mooted in the fashion of the Baker Street and Waterloo Railway becoming the Bakerloo line, such as "Edgmor", "Mordenware", "Medgeway" and "Edgmorden" lines.Template:Sfn

After the UERL and the Metropolitan Railway (MR) became unified under the London Passenger Transport Board (LPTB) in 1933, the MR's Great Northern & City Railway subsidiary, which ran mostly underground from Moorgate to Finsbury Park, transferred management to the Morden–Edgware line, branding itself as the Northern City line.

Northern Heights plan

Script error: No such module "redirect hatnote". Template:Broader

File:Northern Heights diagram.png

Line map of the abandoned Northern Heights plan

File:Northern Line Northern Heights Extension sign.jpg

Sign displaying the route of the Northern Heights extension

Following the formation of the LPTB, in June 1935 the organisation proposed the New Works Programme, an ambitious plan to expand the Underground network in response to London's growing suburban population and relieve congestion on the existing steam-operated suburban lines. In the case of the Morden–Edgware, these were the London and North Eastern Railway (LNER) suburban lines north of Highgate, built in the 1860s and 1870s by the Edgware, Highgate and London Railway (EH&LR) and its successors, running from Finsbury Park to Edgware via Highgate, with branches to Alexandra Palace and High Barnet.

The Morden–Edgware line's project, known as the Northern Heights plan owing to the high ground in north London,^[5] involved fourth-rail electrification of the surface lines and the double-tracking of the single-line section between Finchley (Church End) and Edgware. The Northern Heights plan also called for the construction of three new linking sections of track: between the Northern City line and new surface level platforms at Finsbury Park; a deep-level tunnel from Archway to East Finchley; and a diversion of the Mill Hill branch to the LPTB's Edgware station.^[6]

In addition, the Edgware branch would also be extended beyond the terminus to a site at Bushey Heath, the LPTB having retained planning rights of the unbuilt Watford and Edgware Railway, which had long intended an extension of the EH&LR's Edgware branch towards Watford. A new depot at Aldenham, just before the Bushey Heath terminus, would also be constructed to facilitate the housing of additional trains.^[7] As a result of the project's name, the Morden–Edgware line was renamed as the Northern line.^[8]^[9]^[10]

Work began on the initial stages of the extensions in 1936, as did that on Bushey Heath following its authorisation in 1937, with completion projected by 1941.^[6] The tunnelling northwards from Archway was the first element to be completed and an initial service to the rebuilt East Finchley station commenced on 3 July 1939, though trains skipped the deep-level platforms at Highgate until its fitout was completed by 19 January 1941.

Further progress was disrupted by the start of the Second World War in September 1939; however enough development had been made to complete the electrification of the High Barnet branch, over which tube services started on 14 April 1940, and the single-track LNER line to Edgware being electrified as far as Mill Hill East, reopening as a tube service on 18 May 1941 to serve the nearby Inglis Barracks. The partially-complete depot at Aldenham was converted into an aircraft factory, constructing Handley Page Halifax bombers as part of the war effort.^[7]^[11] Other work on the extension that were eventually halted during the Second World War included the construction of a viaduct at Brockley Hill and a tunnel near Elstree South which started in June 1939, the laying of a second line as far as Mill Hill (The Hale) and the construction of its second platform.^[12]

After the war, much of the area beyond Edgware was made part of the Metropolitan Green Belt that largely prevented the anticipated residential development, thus the potential demand for services from Bushey Heath vanished.^[7] A compromise was offered to make Brockley Hill the line's terminus and retain a link to Aldenham Depot,^[6] but the Bushey Heath extension was cancelled in 1950.^[13] Although efforts were made to complete Aldenham Depot as an Underground facility, from December 1947 it was modified for use as a heavy repair works of bus bodies, supposedly temporarily until Aldenham was required for railway purposes. Following the extension's cancellation, the depot was converted into an overhaul facility for buses, serving this purpose until 1986.^[14]

The introduction of electric services to High Barnet and Mill Hill East undermined passenger numbers on the remaining LNER-operated lines. Consequently, passenger services to Mill Hill (The Hale) and Edgware, having been suspended in September 1939 to allow works to be completed, never resumed^[12] and the Alexandra Palace branch line via the surface platforms at Highgate ceased to passenger traffic on 3 July 1954, with the last of the Northern Heights plans also being dropped that year.^[6] Available funds were directed towards completing the eastern extension of the Central line instead. Freight-hauled mainline trains continued to run alongside Northern line services until 1964.^[15] Tickets were still being sold to and from Mill Hill (The Hale) until the late 1960s, with passengers being directed onto the 240 bus to connect with the Underground.^[12]

The connection between Drayton Park and the surface platforms at Finsbury Park, which gave access onto the Finsbury Park–Highgate line, was retained for rolling stock transfers between the Northern City and Northern line until 1970, the incomplete electrification on this section necessitating stock being hauled by battery-electric locomotives.^[6] Passenger services commenced on the Finsbury Park link in 1976, when the Northern City line transferred to British Rail ownership.

Recent developments

File:Northern line cab.JPG

Close-up of a High Barnet-bound Northern line 1995 stock cab

In a separate proposal to the New Works Programme, the LPTB looked into extending the Northern line south of Morden to North Cheam as late as 1944 alongside a relief line from Kennington to Epsom via Morden.^[16] Further proposals included building additional tunnels between Kennington and Tooting Broadway to relieve congestion, with alternative duplication suggested between Golders Green and Waterloo.^[17] In the 1980s, an extension of the Northern line to Peckham Rye and Streatham Hill was proposed as part of a review of potential extensions of Underground lines.^[18]

Between 1989 and 1992, Angel tube station was rebuilt with a new northbound tunnel alongside the existing station platforms which were widened to become the new southbound platform, replacing the old narrow platforms which by then had become a safety hazard with increased passenger ridership.^[19] A similar project was undertaken at Euston in the 1960s in conjunction with the construction of the Victoria line^[19] and at Bank in the early 2020s in order to increase station capacity and improve accessibility.^[20]^[21]

By the early 1990s, the line had deteriorated due to years of under-investment and the use of old rolling stock, most of which dated back to the early 1960s.^[22] The line gained the nickname "Misery Line" due to its perceived unreliability.^[23]^[24] In 1995, a comprehensive refurbishment of the line began – including track replacement, power upgrades, station modernisation (such as Mornington Crescent) and the replacement of older rolling stock with new 1995 Stock thanks to a public–private partnership deal with Alstom.^[25]^[26]

The Northern line was originally scheduled to switch to automatic train operation in 2012, using the same SelTrac S40 system^[27] as used since 2009 on the Jubilee line and for a number of years on the Docklands Light Railway.^[28] Originally the work was to follow on from the Jubilee line so as to benefit from the experience of installing it there, but that project was not completed until spring 2011. Work on the Northern line was contracted to be completed before the 2012 Olympics. It was then undertaken in-house, and TfL predicted the upgrade would be complete by the end of 2014.^[29] The first section of the line (West Finchley to High Barnet) was transferred to the new signalling system on 26 February 2013^[30] and the line became fully automated on 1 June 2014, with the Chalk Farm to Edgware via Golders Green section being the last part of the line to switch to ATO.^[31]^[32]

Since the mid-autumn of 2016,^[33] a 24-hour "Night Tube" service has run on Friday and Saturday nights from Edgware and High Barnet to Morden via the Charing Cross branch; service is suspended on the Bank branch during these times.^[34] Trains run every eight minutes between Morden and Camden Town and up to every 16 minutes on the Edgware and High Barnet branches. Labour disputes delayed the planned start date of September 2015.^[35]

In January 2018, Transport for London announced that it would double the period during which it runs peak evening services in the central London section to tackle overcrowding. There would now be 24 trains per hour on both central London branches and the northern branches, as well as 30 trains per hour on the Kennington to Morden section between 5Template:Nbsppm and 7Template:Nbsppm.^[1]

Battersea extension

Script error: No such module "Labelled list hatnote". Throughout the 2000s, no plans were considered for extending the Northern line, as the PPP contracts to upgrade the Underground did not include provision for line extensions.^[36]^[37] This prolonged period without an extension ultimately changed when the Northern line was extended to serve the redevelopment of Battersea Power Station in 2021. Partially funded by private developers, the £1.2bn project extended the Charing Cross branch of the line for Template:Convert from Kennington to Battersea Power Station,^[38] with an intermediate stop at Nine Elms.^[39]^[40] Approved by Wandsworth Council in 2010^[41] and TfL in 2014,^[39] construction began in 2015. Tunnelling for the project was completed in 2017,^[38] and the extension opened on 20 September 2021.^[42]^[43] Provision has been made for a future extension to Clapham Junction.^[44]

Services

Peak

As of September 2021, morning peak southbound services are:^[45]

4 tph from Edgware to Battersea Power Station via Charing Cross
2 tph from Edgware to Morden via Charing Cross
12 tph from Edgware to Morden via Bank
10 tph from High Barnet to Battersea Power Station via Charing Cross
2 tph from High Barnet to Morden via Charing Cross
8 tph from High Barnet to Morden via Bank
2 tph from Mill Hill East to Battersea Power Station via Charing Cross
2 tph from Mill Hill East to Morden via Bank

This service pattern provides 20 tph between Finchley Central and High Barnet, 4 tph between Finchley Central and Mill Hill East, 16 tph between Kennington and Battersea Power Station and 22 tph everywhere else on the line except between Kennington and Morden, between Camden Town and Finchley Central and on the Edgware branch where there are 24 tph.

Off-peak

As of November 2022, off-peak services are the similar to peak services, minus the four hourly trains that run from Morden to the northern branches via Charing Cross:^[45]

10 tph from Edgware to Battersea Power Station via Charing Cross
10 tph from Edgware to Morden via Bank
8 tph from High Barnet to Battersea Power Station via Charing Cross
8 tph from High Barnet to Morden via Bank
2 tph from Mill Hill East to Battersea Power Station via Charing Cross
2 tph from Mill Hill East to Morden via Bank

This service pattern provides 16 tph between Finchley Central and High Barnet, 4 tph between Finchley Central and Mill Hill East, and 20 tph everywhere else on the line.

Night

Since 2016, the Northern line has operated Night Tube services on Friday and Saturday nights between the Edgware and High Barnet termini and Morden via the Charing Cross branch only. Trains run every 15 minutes on each of the northern branches, combining to give eight trains per hour between Camden Town and Morden. There is no Night Tube service on the Mill Hill East, Bank or Battersea branches.^[33]

4 tph from High Barnet to Morden via Charing Cross
4 tph from Edgware to Morden via Charing Cross

Map

Geographical path of the Northern line

Stations

Template:Northern line map

File:Step-free access notification (Northern line).png

Notice explaining about step-free access. This can be found inside every Northern line train.

Open stations

High Barnet branch

Station	Image	Opened	Branch	Additional information
High Barnet Disabled access	File:High Barnet stn entrance.JPG	1 April 1872	High Barnet branch	Terminus. Northern line introduced 14 April 1940^{map 1}
Totteridge & Whetstone	File:Totteridge & Whetstone stn building.JPG			Northern line introduced 14 April 1940 ^{map 2}
Woodside Park Disabled access	File:Woodside Park stn building.JPG			Northern line introduced 14 April 1940^{map 3}
West Finchley Disabled access	File:West Finchley stn entrance.JPG	1 March 1933		Northern line introduced 14 April 1940^{map 4}
Mill Hill East Disabled access	File:Mill Hill East stn building.JPG	22 August 1867	Mill Hill branch	Closed 11 September 1939, reopened 18 May 1941^{map 5}
Finchley Central Disabled access	File:Finchley Central station.jpg		High Barnet & Mill Hill branches	First Northern line train was 14 April 1940^{map 6}
East Finchley	File:East Finchley stn building.JPG		High Barnet branch	First Northern line train was 3 July 1939^{map 7}
Highgate	File:Highgate station entrance Priory.JPG	19 January 1941		Disused surface station opened 22 August 1867^{map 8}
Archway	File:Archway station side entrance.JPG	22 June 1907		Originally named Highgate^{map 9}
Tufnell Park	File:Tufnell Park stn building.JPG			^{map 10}
Kentish Town Template:Rail-interchange Template:Rail-interchange	File:Kentish Town stn building.JPG			Mainline station opened 13 July 1868. Change for National Rail services.^{map 11}

Edgware branch

Station	Image	Opened	Additional information
Edgware Disabled access	File:Edgware station building.JPG	18 August 1924	Terminus^{map 12}
Burnt Oak	File:Burnt Oak stn building.JPG	27 October 1924	Opened with its current name, then renamed as "Burnt Oak (Watling)" approximately four years after its opening; was reverted to its original name in 1950.^{map 13}
Colindale	File:Colindale station entrance.JPG	18 August 1924	Used as a terminus for some trains travelling north.^{map 14}
Hendon Central Disabled access	File:Hendon Central stn entrance.JPG	19 November 1923	^{map 15}
Brent Cross	File:Brent Cross stn building.JPG	19 November 1923	Opened as "Brent"; renamed 20 July 1976.^{map 16}
Golders Green Disabled access	File:Golders Green stn building.JPG	22 June 1907	Originally a terminus; remains a terminus for some trains.^{map 17}
Hampstead	File:Hampstead station building.JPG		Originally proposed to be named "Heath Street"; this name can still be seen on wall tilings on station platform walls.^{map 18}
Belsize Park	File:Belsize Park stn building.JPG		One of eight London Underground stations that have deep-level air-raid shelters underneath them. The shelter was constructed in the Second World War to provide safe accommodation for service personnel.^{map 19}
Chalk Farm	File:Chalk Farm stn entrance.JPG		^{map 20}

Camden Town

Station	Image	Opened	Branch	Additional information
Camden Town	File:Camden Town stn building2.JPG	22 June 1907	Edgware, High Barnet, Charing Cross and Bank branchesTemplate:Efn	The junctions connecting the two northern branches of the Northern line to the two central branches are just south of Camden Town station. The station has a pair of platforms on each of the two northern branches, and southbound trains can depart toward either Charing Cross or Bank from either of the two southbound platforms without crossing over.^{map 21}

Charing Cross branch

Station	Image	Opened	Additional information
Mornington Crescent	File:Mornington Crescent stn building.JPG	22 June 1907	Was planned to be named "Seymour Street", but this was changed. It was closed on 23 October 1992 to replace the lifts and was reopened on 27 April 1998.^{map 22}
Euston (Charing Cross branch) Template:Rail-interchange Template:Rail-interchange	File:Euston station facade.jpg		Change for southbound Northern line service via Bank from platform 6, Victoria line, Lioness line and National Rail services^{map 23}
Warren Street	File:Warren Street stn entrance.JPG		Change for Victoria line^{map 24}
Goodge Street	File:Goodge Street stn entrance.JPG		Opened as "Tottenham Court Road"; renamed 3 September 1908^{map 25}
Tottenham Court Road Disabled access Template:Rail-interchange	File:Tottenham Court Road stn main entrance under refurb Oct 09.JPG		Change for Central line and Elizabeth line.
Leicester Square	File:Leicester Square stn northwest entrance.JPG		Piccadilly line opened 15 December 1906 ^{map 27}
Charing Cross Template:Rail-interchange	File:Charing Cross tube station 1.jpg		Bakerloo line opened as Trafalgar Square 10 March 1906. Stations combined 1 May 1979. Change for Bakerloo line and National Rail services^{map 28}
Embankment (Template:Rail-interchange Embankment Pier)	File:Embankment station.jpg	6 April 1914	District Railway opened 30 May 1870. Northern line extension from Charing Cross opened 6 April 1914. Extension from Kennington opened 13 September 1926. Change for Bakerloo, Circle and District lines^{map 29}
Waterloo Template:Rail-interchange (Template:Rail-interchange Waterloo Pier, Festival Pier)	File:Waterloo tube stn entrance.JPG	13 September 1926	Waterloo and City line opened 8 August 1898. Extension from Kennington opened 13 September 1926. Change for Bakerloo, Jubilee and Waterloo & City lines and National Rail services^{map 30}

Bank branch

Station	Image	Opened	Additional information
Euston (Bank branch) Template:Rail-interchange Template:Rail-interchange	File:Euston station facade.jpg	12 May 1907	Change for southbound Northern line service via Charing Cross from platform 2, Victoria line, Lioness line and National Rail services^{map 23}
King's Cross St Pancras Disabled access Template:Rail-interchange Template:Rail-interchange Template:Rail-interchange (Template:Rail-interchange Trains Gatwick and Luton)	File:King's Cross St Pancras tube stn Euston Rd NE entrance.JPG	12 May 1907	Metropolitan Railway station opened 10 January 1863. Change for Circle, Hammersmith & City, Metropolitan, Piccadilly and Victoria lines, National Rail services and Eurostar^{map 31}
Angel	File:Angel station entrance.JPG	17 November 1901	Has the longest escalator on the entire Underground network^{map 32}
Old Street Template:Rail-interchange	File:Old Street stn northwest entrance.JPG	17 November 1901	Northern line platforms opened February 1904. Connects with National Rail services.^{map 33}
Moorgate Template:Rail-interchange Template:Rail-interchange	File:Moorgate entrance Mgate.JPG	25 February 1900	Metropolitan Railway station opened 23 December 1865. Change for Circle, Hammersmith & City and Metropolitan lines and National Rail services.^{map 34} Has an interchange with the Elizabeth line via Liverpool Street station.
Bank Disabled access Template:Rail-interchange	File:Bank station entrance look to Bank.JPG		Linked with Monument by escalator 18 September 1933, change for Central, Circle, District and Waterloo & City lines and Docklands Light Railway.^{map 35}
London Bridge Disabled access Template:Rail-interchange Template:Rail-interchange (Template:Rail-interchange Trains to Gatwick and Luton) (Template:Rail-interchange London Bridge City Pier)	File:London Bridge tube stn entrance Borough High St.JPG		Change for Jubilee line and National Rail services^{map 36}
Borough	File:Borough station building.JPG	18 December 1890	^{map 37}
Elephant & Castle Template:Rail-interchange Template:Rail-interchange	File:Elephant & Castle stn south entrance.JPG	18 December 1890	Change for Bakerloo line and National Rail services^{map 38}

Kennington

Station	Image	Opened	Branch	Additional information
Kennington	File:Kennington station building.JPG	18 December 1890	Charing Cross, Bank, Battersea and Morden branchesTemplate:Efn	The station has four platforms arranged in two pairs: one pair for northbound services to each central branch of the Northern line, the other pair for southbound services from each central branch. The junctions connecting the central branches to the southern branches are just south of Kennington station. Southbound trains from the Charing Cross branch can terminate at this station, which has a reversing loop, or join either southern branch; southbound trains from the Bank branch can proceed onto the Morden branch but not the Battersea branch.^{map 39}

Battersea branch

Station	Image	Opened	Additional information
Nine Elms Disabled access	File:Nine Elms Station, Platform Concourse (51497388149).jpg	20 September 2021
Battersea Power Station Disabled access	File:Battersea Power Station Station (51496672361).jpg	20 September 2021	Terminus

Morden branch

Station	Image	Opened	Additional information
Oval	File:Oval station building.JPG	18 December 1890	^{map 40}
Stockwell	File:Stockwell station building.JPG	18 December 1890	Change for Victoria line. Original terminus until 1900, when the line was extended to Clapham Common. The station platforms were resited south of the original island platform. Formerly a depot existed here; it was branched off from the current southbound track. It is one of the eight stations that have a deep level air-raid shelter. ^{map 41}
Clapham North	File:Clapham North stn entrance.JPG	3 June 1900	One of the two remaining stations to have an island platform underground. It is also one of the eight stations that have a deep level air-raid shelter.^{map 42}
Clapham Common	File:Clapham Common Tube Station Exterior - Oct 2007.jpg	3 June 1900	Terminus from 1900 to 1926. It is also one of the two remaining stations to have an island platform underground. It is also one of the eight stations that have a deep level air-raid shelter.^{map 43}
Clapham South	File:ClaphamSouthTube.jpg	13 September 1926	One of the eight stations that have a deep level air-raid shelter.^{map 44}
Balham Template:Rail-interchange	File:Balham station.jpg	6 December 1926	Change for National Rail services^{map 45}
Tooting Bec	File:Tooting Bec stn west entrance.JPG	13 September 1926	Opened as "Trinity Road"; renamed 1 October 1950^{map 46}
Tooting Broadway	File:Tooting Broadway stn building.JPG		Used as a terminus for some trains heading south^{map 47}
Colliers Wood	File:Colliers Wood stn entrance.JPG		^{map 48}
South Wimbledon	File:South Wimbledon stn entrance.JPG		Opened as "South Wimbledon (Merton)". The suffix gradually fell out of use, but still can be seen on some platform signage.^{map 49}
Morden Disabled access	File:Morden Tube Station.jpg		Terminus^{map 50}

Closed stations

Script error: No such module "Labelled list hatnote".

Permanently closed stations

King William Street (closed 1900; replaced by Bank)
City Road (closed 1922)
South Kentish Town (closed 1924)
North End (also known as "Bull & Bush". Never opened; work stopped 1906)

Resited stations

Stockwell – new platforms resited immediately to the south of its predecessor with the 1922–1924 upgrade of the line.
London Bridge – the northbound tunnel and platform converted into a concourse, and a new northbound tunnel and platform built in the late 1990s to increase the platform and circulation areas in preparation for the opening of the Jubilee line.

Abandoned plans

Northern Heights stations not transferred from LNER

Bushey Extension stations not constructed

Infrastructure

Rolling stock

File:1995ts at Finchley Central.jpg

A High Barnet-bound Northern line train arriving at Finchley Central

When the line opened, it was served by 1906 Stock. This was replaced by Standard stock which was in turn replaced by 1938 stock as part of the New Works Programme, later supplemented with identical 1949 Stock. When the Piccadilly line was extended to Heathrow Airport in the 1970s, its 1959 Stock and 1956 Stock (prototypes of the 1959 Stock) trains were transferred to the Northern line. As there were not enough 1956 and 1959 Stock trains to replace the Northern line's 1938 Stock fleet, they were supplemented with newly built 1972 Mark 1 Stock trains, which all served the line at the same time. 1972 Mark 2 stock trains also ran on this line until going to the Jubilee line; they were then moved to the Bakerloo line, where they remain in service. By 1986, increasing unreliability of 1959 stock trains meant there were regularly too few trains to run a full peak service. Five 1938 stock trains, newly retired from the Bakerloo Line, were overhauled and returned to the Northern Line to serve another two years until further 1972 stock could be transferred from the Jubilee Line, which was moving to 1983 stock. The few 1956 Stock trains were briefly replaced by 1962 Stock transferred from the Central line in 1995, before the entire Northern line fleet was replaced with 1995 Stock between 1998 and 2000.

Today, all Northern line trains consist of 1995 Stock in the Underground livery of red, white and blue. In common with the other deep-level lines, the trains are the smaller of the two loading gauges used on the system. 1995 stock has automated announcements and quick-close doors.Script error: No such module "Unsubst". If the proposed split of the line takes place (initial estimates of 2018 having been abandoned to focus on completion of the Battersea and Nine Elms extension work), 19 new trains will be added to the existing fleet of 106 trains,^[46] though additional trains beyond the extra 19 trains may be required to provide a full service for the new Battersea extension.

Tunnels

Although two other London Underground lines operate fully underground, the Northern line is unusual in that it is a deep-level tube line that serves the outer suburbs of South London yet there is only one station above ground (Morden tube station) while the rest of this part of the line is deep below ground. The short section to Morden depot is also above ground. This is partly because its southern extension into the outer suburbs was not done by taking over an existing surface line as was generally the case with routes such as the Central, Jubilee and Piccadilly lines. Apart from the core central underground tunnels, part of the section between Hendon and Colindale is also underground. As bicycles are not allowed in tunnel sections (even if no station is in that section) as they would hinder evacuation, they are limited to High Barnet – East Finchley, the Mill Hill East branch, Edgware – Colindale and Hendon Central – Golders Green.^[47] There are also time-based restrictions for the sections where bicycles are allowed.^[47]

The tunnel from Morden to East Finchley via Bank, 17 miles 528 yards (27.841 km),^[48] was for a time the longest rail tunnel in the world. Other tunnels, including the Channel Tunnel that links the UK and France, are now longer.

Depots

The Northern line is serviced by four depots. The main one is at Golders Green^{map 51}, adjacent to Golders Green tube station, while the second, at Morden,^{map 52} is south of Morden tube station and is the larger of the two. The other two are at Edgware and Highgate. The Highgate depot is on the former LNER branch to Alexandra Palace. There was originally a depot at Stockwell, but this closed in 1915. There are sidings at High Barnet for stabling trains overnight.

Future

Northern line split

Since the 2000s, TfL has aspired to split the Northern line into two routes.^[49]^[50] Running trains between all combinations of branches and the two central sections, as at present, means only 24 trains an hour can run through each of the central sections at peak times, because merging trains have to wait for each other at the junctions at Camden Town and Kennington.^[51] Completely segregating the routes could allow 36 trains an hour on all parts of the line, increasing capacity by around 25%.^[49]^[51]

TfL has already separated the Charing Cross and Bank branches during off-peak periods; however, four trains per hour still run to and from Morden via Charing Cross in the peak; the northern branches to Edgware and High Barnet cannot be separated until Camden Town station is upgraded to cope with the numbers of passengers changing trains.^[52] The extension to Battersea would allow the Charing Cross branch to terminate at Battersea Power Station.^[53]^[54]

The proposed split of the Northern line would require Camden Town station to be expanded and upgraded, as the station is already severely overcrowded at weekend peak times, and a split would increase the number of passengers wishing to change trains at the station.^[54]^[55]^[52] In 2005, London Underground failed to secure planning permission for a comprehensive upgrade plan for Camden Town tube station that would have involved demolition of the existing station entrance and several other surface-level buildings, all within a conservation area.^[56]^[57] New redevelopment plans were first announced in 2013 by TfL, which proposed avoiding the existing station entrance and the conservation area by building a second entrance and interchange tunnels to the north, mostly on the site of a subsequently vacated infant school.^[55] In 2018, plans to upgrade and rebuild Camden Town station were placed indefinitely on hold, due to TfL's financial situation.^[58] Template:As of, TfL said they still "aspire" to split the line. A partial separation was proposed in which all trains from Morden would operate via Bank, while those starting at Kennington (or Battersea) would serve the Charing Cross branch. The High Barnet and Edgware branches would remain served by trains from both routes.^[59]

Incidents and accidents

In October 2003, a train derailed at Camden Town.^[60] Although no one was hurt, points, signals and carriages were damaged. Concern was raised about the safety of the Tube, given the derailment at Chancery Lane earlier in 2003.^[61] A joint report by the Underground and its maintenance contractor Tube Lines concluded that poor track geometry was the main cause, and therefore extra friction arising out of striations (scratches) on a newly installed set of points had allowed the leading wheel of the last carriage to climb the rail and derail. The track geometry at the derailment site is a very tight bend and tight tunnel bore, which precludes the normal solution for this sort of geometry of canting the track by raising the height of one rail relative to the other.^[62]

In August 2010, a defective rail grinding train caused disruption on the Charing Cross branch, after it travelled four miles in 13 minutes without a driver. The train was being towed to the depot after becoming faulty. At Archway station, the defective train became detached and ran driverless until coming to a stop at an incline near Warren Street station. This caused morning rush-hour services to be suspended on this branch. All passenger trains were diverted via the Bank branch, with several not stopping at stations until they were safely on the Bank branch.^[63]^[64]

In popular culture

In his debut novel Ghostwritten, David Mitchell characterises the Northern line as "the psycho of the family".^[65]
The Bloc Party song "Waiting For the 7.18" references the Northern line as "the loudest".^[66]
As part of a series of twelve books tied to the twelve lines of the London Underground, A Northern Line Minute focuses on the Northern line.^[67]
The New Vaudeville Band's 1967 song "Finchley Central" ("On Tour" in the US) mentions several stations on the line.^[68]
The Nick Drake song "Parasite" references the Northern Line.^[69]
The 1982 Robyn Hitchcock song "Fifty Two Stations" begins, "There's fifty-two stations on the Northern Line/None of them is yours, one of them is mine."^[70]
The 2021 Maisie Peters song "Elvis Song" begins, "Cold bench on a platform/Last train on the Northern Line."^[71]

Maps

Template:Div col

<templatestyles src="Citation/styles.css"/>^map 1 High Barnet – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 2 Totteridge & Whetstone – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 3 Woodside Park – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 4 West Finchley – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 5 Mill Hill East – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 6 Finchley Central – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 7 East Finchley – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 8 Highgate – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 9 Archway – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 10 Tufnell Park – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 11 Kentish Town – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 12 Edgware – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 13 Burnt Oak – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 14 Colindale – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 15 Hendon Central – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 16 Brent Cross – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 17 Golders Green – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 18 Hampstead – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 19 Belsize Park – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 20 Chalk Farm – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 21 Camden Town – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 22 Mornington Crescent – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 23 Euston – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 24 Warren Street – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 25 Goodge Street – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 26 Tottenham Court Road – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 27 Leicester Square – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 28 Charing Cross – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 29 Embankment – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 30 Waterloo – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 31 King's Cross St Pancras – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 32 Angel – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 33 Old Street – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 34 Moorgate – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 35 Bank-Monument – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 36 London Bridge – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 37 Borough – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 38 Elephant & Castle – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 39 Kennington – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 40 Oval – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 41 Stockwell – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 42 Clapham North – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 43 Clapham Common – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 44 Clapham South – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 45 Balham – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 46 Tooting Bec – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 47 Tooting Broadway – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 48 Colliers Wood – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 49 South Wimbledon – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 50 Morden – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 51 Golders Green depot – Template:Coord
<templatestyles src="Citation/styles.css"/>^map 52 Morden depot – Template:Coord

Template:Div col end Template:GeoGroup

References

Script error: No such module "Citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".

Template:Refend

External links

Template:Sister project Template:Attached KML

Template:Northern line navbox

↑ ^a ^b Script error: No such module "citation/CS1".
↑ Template:London Gazette
↑ Template:London Gazette
↑ Template:London Gazette
↑ Script error: No such module "citation/CS1".
↑ ^a ^b ^c ^d ^e Script error: No such module "citation/CS1".
↑ ^a ^b ^c Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Rails through the Clay; Croome & Jackson; London; 2nd ed; 1993; p228
↑ Script error: No such module "Citation/CS1".Template:Subscription required
↑ Script error: No such module "citation/CS1".
↑ ^a ^b ^c Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".Template:Cbignore
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".Template:Dead link
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Abbot 2010, pp. 57–58.
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Cite error: Invalid <ref> tag; no text was provided for refs named linefact
↑ ^a ^b Template:Cite CiteSeerX
↑ Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1".
↑ ^a ^b Script error: No such module "citation/CS1". Detailed report, with updated timeline etc.
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Template:Cite magazine
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".
↑ Script error: No such module "citation/CS1".

[cityam-1] Script error: No such module "citation/CS1".

[gazette_1-2] Template:London Gazette

[gazette_2-3] Template:London Gazette

[gazette_3-4] Template:London Gazette

[5] Script error: No such module "citation/CS1".

[Northern_Wastes-6] Script error: No such module "citation/CS1".

[Beyond_Edgware-7] Script error: No such module "citation/CS1".

[8] Script error: No such module "citation/CS1".

[9] Rails through the Clay; Croome & Jackson; London; 2nd ed; 1993; p228

[new_name-10] Script error: No such module "Citation/CS1".Template:Subscription required

[11] Script error: No such module "citation/CS1".

[Mill_Hill_(The_Hale)-12] Script error: No such module "citation/CS1".

[13] Script error: No such module "citation/CS1".

[14] Script error: No such module "citation/CS1".

[15] Script error: No such module "citation/CS1".

[16] Script error: No such module "citation/CS1".

[17] Script error: No such module "citation/CS1".

[18] Script error: No such module "citation/CS1".

[Clive-19] Script error: No such module "citation/CS1".

[20] Script error: No such module "citation/CS1".

[21] Script error: No such module "citation/CS1".

[22] Script error: No such module "citation/CS1".

[23] Script error: No such module "citation/CS1".Template:Cbignore

[misery1-24] Script error: No such module "citation/CS1".

[25] Script error: No such module "citation/CS1".

[26] Script error: No such module "citation/CS1".

[thereg-20160809-27] Script error: No such module "citation/CS1".

[Tube_Lines-28] Script error: No such module "citation/CS1".

[29] Script error: No such module "citation/CS1".

[30] Script error: No such module "citation/CS1".

[31] Script error: No such module "citation/CS1".

[32] Script error: No such module "citation/CS1".Template:Dead link

[:3-33] Script error: No such module "citation/CS1".

[34] Script error: No such module "citation/CS1".

[35] Script error: No such module "citation/CS1".

[36] Script error: No such module "citation/CS1".

[37] Script error: No such module "citation/CS1".

[:0-38] Script error: No such module "citation/CS1".

[:1-39] Script error: No such module "citation/CS1".

[:2-40] Script error: No such module "citation/CS1".

[41] Script error: No such module "citation/CS1".

[42] Script error: No such module "citation/CS1".

[BBC-Battersea-43] Script error: No such module "citation/CS1".

[44] Script error: No such module "citation/CS1".

[londonreconnections.com-45] Script error: No such module "citation/CS1".

[46] Abbot 2010, pp. 57–58.

[bicycle-47] Script error: No such module "citation/CS1".

[linefact-48] Cite error: Invalid <ref> tag; no text was provided for refs named linefact

[:02-49] Template:Cite CiteSeerX

[50] Script error: No such module "citation/CS1".

[TwinPeaks-51] Script error: No such module "citation/CS1".

[:4-52] Script error: No such module "citation/CS1".

[53] Script error: No such module "citation/CS1".

[:412-54] Script error: No such module "citation/CS1".

[upcap12-55] Script error: No such module "citation/CS1". Detailed report, with updated timeline etc.

[56] Script error: No such module "citation/CS1".

[2ndTimeLucky-57] Script error: No such module "citation/CS1".

[58] Script error: No such module "citation/CS1".

[f763-59] Script error: No such module "citation/CS1".

[60] Script error: No such module "citation/CS1".

[61] Script error: No such module "citation/CS1".

[62] Template:Cite magazine

[63] Script error: No such module "citation/CS1".

[64] Script error: No such module "citation/CS1".

[65] Script error: No such module "citation/CS1".

[66] Script error: No such module "citation/CS1".

[67] Script error: No such module "citation/CS1".

[68] Script error: No such module "citation/CS1".

[69] Script error: No such module "citation/CS1".

[70] Script error: No such module "citation/CS1".

[71] Script error: No such module "citation/CS1".

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

[22]

[23]

[24]

[25]

[26]

[27]

[28]

[29]

[30]

[31]

[32]

[33]

[34]

[35]

[36]

[37]

[38]

[39]

[40]

[41]

[42]

[43]

[44]

[45]

[46]

[47]

[48]

[49]

[50]

[51]

[52]

[53]

[54]

[55]

[56]

[57]

[58]

[59]

[60]

[61]

[62]

[63]

[64]

[65]

[66]

[67]

[68]

[69]

[70]

[71]

@@ Line 24: / Line 24: @@
 | depot                           = {{plainlist|
 * {{cslist|Golders Green|Morden}}
-* {{cslist|Highgate|Edgware|High Barnet<ref name="linefact">{{cite web |title=Northern line facts |url= http://www.tfl.gov.uk/corporate/modesoftransport/londonunderground/keyfacts/13174.aspx |archive-url=https://web.archive.org/web/20120312094056/https://tfl.gov.uk/corporate/modesoftransport/londonunderground/keyfacts/13174.aspx |archive-date=12 March 2012 |publisher=Transport for London |access-date=12 March 2012}}</ref>}}
+* [[Stabling point|Stabling Sidings]]: {{cslist|Highgate|Edgware|High Barnet<ref name="linefact">{{cite web |title=Northern line facts |url= http://www.tfl.gov.uk/corporate/modesoftransport/londonunderground/keyfacts/13174.aspx |archive-url=https://web.archive.org/web/20120312094056/https://tfl.gov.uk/corporate/modesoftransport/londonunderground/keyfacts/13174.aspx |archive-date=12 March 2012 |publisher=Transport for London |access-date=12 March 2012}}</ref>}}
 }}
 | stock                           = [[London Underground 1995 Stock|1995 Stock]]
@@ Line 33: / Line 33: @@
 | linelength_km                   = 58
 | tracklength_km                  =
-| website                         = [http://www.tfl.gov.uk/ tfl.gov.uk]
+| website                         = {{Official URL}}
 | map_name                        = [[Transport for London]] rail&nbsp;lines
 | map                             = {{London rail lines}}
@@ Line 39: / Line 39: @@
 }}
-The '''Northern line''' is a [[London Underground]] line that runs between [[North London]] and [[South London]]. It is printed in black on the [[Tube map]]. It carries more passengers per year than any other Underground line{{snd}}around 340{{nbsp}}million in 2019{{snd}}making it the busiest tube line in London. The Northern line is unique on the network in having two different routes through Central London, two northern branches and two southern branches. Despite its name, it does not serve the northernmost stations on the Underground, though it does serve the southernmost station at [[Morden tube station|Morden]], the terminus of one of the two southern branches.
+The '''Northern line''' is a [[London Underground]] line that runs between [[North London]] and [[South London]]. It is printed in black on the [[Tube map]]. It carries more passengers per year than any other Underground line{{snd}}around 340{{nbsp}}million in 2019{{snd}}making it the busiest tube line in London. The Northern line is unique on the network in having two routes through Central London, two northern branches and two southern branches. Despite its name, it does not serve the northernmost stations on the Underground, though it does serve the southernmost station at [[Morden tube station|Morden]], the terminus of one of the two southern branches.
 The line's northern termini, all in the [[London Borough of Barnet]], are at {{lus|Edgware}} and {{lus|High Barnet}}; {{lus|Mill Hill East}} is the terminus of a single-station branch line off the High Barnet branch. The two main northern branches run south to join at {{lus|Camden Town}} where two routes, one via {{lus|Charing Cross}} in the [[West End of London|West End]] and the other via {{lus|Bank}} in the [[City of London|City]], continue and then join at {{lus|Kennington}} in [[London Borough of Southwark|Southwark]]. At Kennington the line again divides into two branches, one to each of the southern termini – at {{lus|Morden}}, in the borough of [[London Borough of Merton|Merton]], and at {{lus|Battersea Power Station}} in [[London Borough of Wandsworth|Wandsworth]].
-For most of its length the Northern line is a deep tube line.{{#tag:ref|A "tube" railway is an underground railway constructed in a cylindrical tunnel by the use of a [[tunnelling shield]], usually deep below ground level.|group=nb}} The portion between {{lus|Stockwell}} and {{lus|Borough}} opened in 1890 and is the oldest section of deep-level tube line on the network. Nearly 340&nbsp;million passenger journeys were recorded in 2019 on the Northern line, making it the busiest on the Underground, although this is distorted due to having 2 branches within Central London, both of which are less busy than the core sections of other lines.<ref name="cityam" /> It has 18 of the system's 31 stations south of the [[River Thames]]. There are 52 stations in total on the line, of which 38 have platforms below ground.
+For most of its length the Northern line is a deep tube line.{{efn|A "tube" railway is an underground railway constructed in a cylindrical tunnel by the use of a [[tunnelling shield]], usually deep below ground level.}} The portion between {{lus|Stockwell}} and {{lus|Borough}} opened in 1890 and is the oldest section of deep-level tube line on the network. Nearly 340&nbsp;million passenger journeys were recorded in 2019 on the Northern line, making it the busiest on the Underground, although this is distorted due to having two branches within Central London, both of which are less busy than the core sections of other lines.<ref name="cityam" /> Despite the line's name, it has 18 of the system's 31 stations south of the [[River Thames]]. There are 52 stations in total on the line, of which 38 have platforms below ground.
-The line's structure of two northern branches (one with a further short branch), two central branches, and two southern branches reflects its complicated history. The core of the line, including the two central branches and the beginnings of the two northern branches, was constructed by two companies, the [[City and South London Railway]] and the [[Charing Cross, Euston and Hampstead Railway]], in the 1890s and 1900s. The companies came under the same ownership in 1913, and were physically connected and operationally merged in the 1920s, while at the same time extensions to Edgware and Morden were completed. In the 1930s and 1940s the Northern line took over and electrified the [[London and North Eastern Railway]] branches to Mill Hill East and High Barnet. This was the final extension of the line for eight decades, though between the 1930s and 1970s the [[Northern City Line]] was branded and operated as part of the Northern line despite being disconnected from the rest of the line. The most recent extension, [[Northern line extension to Battersea|a second southern branch from Kennington to Battersea]], opened on 20 September 2021. There are proposals to split the line into two separate lines.
+The line's structure of two northern branches (one with a further short branch), two central branches, and two southern branches reflects its complicated history. The core of the line, including the two central branches and the beginnings of the two northern branches, was constructed by two companies, the [[City and South London Railway]] and the [[Charing Cross, Euston and Hampstead Railway]], in the 1890s and 1900s. The companies came under the same ownership in 1913, and were physically connected and operationally merged in the 1920s, while at the same time extensions to Edgware and Morden were completed. In the 1930s and 1940s the Northern line took over and electrified the [[London and North Eastern Railway]] branches to Mill Hill East and High Barnet. This was the final extension of the line for eight decades, though between the 1930s and 1970s the [[Northern City Line]] was branded and operated as part of the Northern line despite being disconnected from the rest of the line. The most recent extension, [[Northern line extension to Battersea|a second southern branch from Kennington to Battersea]], opened on 20 September 2021. There are proposals to split the line into two lines.
 {{TOC limit|4}}
@@ Line 56: / Line 56: @@
 The core of the Northern line evolved from two railway companies: the City & South London Railway (C&SLR) and the Charing Cross, Euston & Hampstead Railway (CCE&HR).
-The C&SLR was London's first electric hauled deep-level tube railway. It was built under the supervision of [[James Henry Greathead]], who had been responsible (with [[Peter W. Barlow]]) for the [[Tower Subway]].{{sfn|Badsey-Ellis|2005|p=35}} It was the first of the Underground's lines to be constructed by boring deep below the surface and the first to be operated by electric traction.{{sfn|Wolmar|2005|pp=4 & 135}} The railway opened in November 1890 from [[Stockwell tube station|Stockwell]] to a now-disused station at [[King William Street tube station|King William Street]].{{sfn|Horne|2009|p=10}} This was inconveniently placed and unable to cope with the company's traffic so in 1900 a new route to [[Moorgate station|Moorgate]] via [[Bank–Monument station|Bank]] was opened.{{sfn|Horne|2009|p=14}} By 1907, the C&SLR had been further extended at both ends to run from [[Clapham Common tube station|Clapham Common]] to [[Euston tube station|Euston]].{{sfn|Horne|2009|pp=16–18}}
+The C&SLR was London's first electric hauled deep-level tube railway. It was built under the supervision of [[James Henry Greathead]], who had been responsible for the [[Tower Subway]].{{sfn|Badsey-Ellis|2005|p=35}} It was the first of the Underground's lines to be constructed by boring deep below the surface and the first to be operated by electric traction.{{sfn|Wolmar|2005|pp=4 & 135}} The railway opened in November 1890 from [[Stockwell tube station|Stockwell]] to a now-disused station at [[King William Street tube station|King William Street]].{{sfn|Horne|2009|p=10}} This was inconveniently placed and unable to cope with the company's traffic so in 1900 a new route to [[Moorgate station|Moorgate]] via [[Bank–Monument station|Bank]] was opened.{{sfn|Horne|2009|p=14}} By 1907, the C&SLR had been further extended at both ends to run from [[Clapham Common tube station|Clapham Common]] to [[Euston tube station|Euston]].{{sfn|Horne|2009|pp=16–18}}
-[[File:Formation of the Northern Line small.png|frame|Formation of the Northern line (Northern Heights and Battersea extensions not shown)]]
+[[File:Formation of the Northern Line small.png|frame|Formation of the Northern line up to the 1920s]]
-The CCE&HR (commonly known as the "Hampstead Tube") was opened in 1907 and ran from [[Charing Cross tube station|Charing Cross]] (known for many years as Strand) via Euston and a junction at [[Camden Town tube station|Camden Town]] to [[Golders Green tube station|Golders Green]] and Highgate (now known as [[Archway tube station|Archway]]).{{sfn|Horne|2009|p=26}}{{sfn|Rose|2016}} It was extended south by one stop to [[Embankment tube station|Embankment]] in 1914 to form an interchange with the [[Bakerloo line|Bakerloo]] and [[District line]]s.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=27}} In 1913, the [[Underground Electric Railways Company of London]] (UERL), owner of the CCE&HR, took over the C&SLR although they remained separate companies.{{sfn|Wolmar|2005|p=205}}
+The CCE&HR, commonly known as the "Hampstead Tube", was opened in 1907 and ran from Strand (nowadays [[Charing Cross tube station|Charing Cross]]) via Euston to [[Camden Town tube station|Camden Town]] with branches splitting to [[Golders Green tube station|Golders Green]] and Highgate (nowadays [[Archway tube station|Archway]]).{{sfn|Horne|2009|p=26}}{{sfn|Rose|2016}} It was extended south by one stop to Charing Cross (nowadays [[Embankment tube station|Embankment]]) in 1914 to form an interchange with the [[Bakerloo line|Bakerloo]] and [[District line]]s.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=27}} In 1913, the [[Underground Electric Railways Company of London]] (UERL), owner of the CCE&HR, took over the C&SLR although they remained separate companies for some time.{{sfn|Wolmar|2005|p=205}}
 ===Integration===
-During the early 1920s a series of works were carried out which involved connecting the C&SLR and CCE&HR tunnels to enable an integrated service to be operated. The first of these new tunnels, between the C&SLR's Euston station and the CCE&HR's station at Camden Town, had originally been planned in 1912 but was delayed by the First World War.<ref name="gazette_1">{{London Gazette
+During the early 1920s a series of works were carried out to connect the C&SLR and CCE&HR tunnels to enable an integrated service to be operated. The first of these new tunnels between the C&SLR's Euston and CCE&HR's Camden Town stations had originally been planned in 1912 but was delayed by the [[World War I|First World War]].<ref name="gazette_1">{{London Gazette |issue=28665 |date=22 November 1912 |page=8798}}</ref>{{sfn|Horne|2009|p=32}} Construction began in 1922 and this first tunnel opened in 1924.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=32}} The second connection linking the CCE&HR's Embankment and C&SLR's [[Kennington tube station|Kennington]] stations opened in 1926.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=32}} It provided a new intermediate station at [[Waterloo tube station|Waterloo]] to connect to [[London Waterloo station|the main line station]]. The smaller diameter tunnels of the C&SLR were also enlarged to match the standard diameter of the CCE&HR and other deep tube lines.{{sfn|Horne|2009|pp=32–33}} In conjunction with the works to integrate the two lines, two major extensions were undertaken: northwards to [[Edgware]] in [[Middlesex]] and southwards to [[Morden]] in [[Surrey]].
-| issue = 28665
-| date = 22 November 1912
-| page = 8798
-}}</ref>{{sfn|Horne|2009|p=32}} Construction began in 1922 and this first tunnel opened in 1924.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=32}} The second connection linking the CCE&HR's Embankment and C&SLR's [[Kennington tube station|Kennington]] stations opened in 1926.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=32}} It provided a new intermediate station at [[Waterloo tube station|Waterloo]] to connect to the main line station there and the [[Bakerloo line]]. The smaller diameter tunnels of the C&SLR were also enlarged to match the standard diameter of the CCE&HR and other deep tube lines.{{sfn|Horne|2009|pp=32–33}}
-===Extensions===
+The Edgware extension used plans dating back to 1901 for the [[Charing Cross, Euston and Hampstead Railway#Hampstead Heath controversy|Edgware and Hampstead Railway]]<ref name=gazette_2>{{London Gazette |issue=27380 |date=26 November 1901 |page=8200}}</ref> which the UERL's subsidiary, the [[London Electric Railway]], had taken over in 1912.{{sfn|Horne|2009|p=28}} It extended the CCE&HR line from its terminus at Golders Green to [[Hendon Central tube station|Hendon Central]] in 1923 and to [[Edgware tube station|Edgware]] in 1924.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=29}} The line crossed open countryside and ran mostly on viaduct from Golders Green to [[Brent Cross tube station|Brent]] and then on the surface, apart from a short tunnel north of Hendon Central.{{sfn|Horne|2009|p=29}} Five new stations were built to pavilion-style designs by [[Stanley Heaps]], stimulating the rapid northward expansion of suburban developments in the following years.{{sfn|Day|Reed|2010|p=91}}
-In conjunction with the works to integrate the two lines, two major extensions were undertaken: northwards to [[Edgware]] in [[Middlesex]] (now in the [[London Borough of Barnet]]) and southwards to [[Morden]] in [[Surrey]] (then in the [[Merton and Morden Urban District]], but now in the [[London Borough of Merton]]).
-====Edgware Extension====
+The engineering of the Morden extension of the C&SLR from Clapham Common to Morden was more demanding, running in tunnel to [[Morden tube station|Morden station]] which was then constructed in a cutting and the line continued a bit beyond to the depot. The extension was initially [[Sutton Underground Line Proposal|planned]] to continue to [[Sutton (Surrey) railway station|Sutton]]<ref name=gazette_3>{{London Gazette |issue=32770 |date=24 November 1922 |pages=8314–8315}}</ref> over part of the route of the unbuilt [[Wimbledon and Sutton Railway]] (in which the UERL held a stake) but agreements were made with [[Southern Railway (Great Britain)|Southern Railway]] (SR) to end the extension at Morden, the SR building a surface line from Wimbledon to Sutton in the 1930s via South Merton and St. Helier.{{efn|The stations that the C&SLR were to serve on the W&SR, would not have included all those subsequently built by the Southern Railway. [[Morden tube station (District Railway)|South Morden]] (not built), [[Sutton Common railway station|Sutton Common]], [[Cheam tube station|Cheam]] (not built) and Sutton, would have been served, but [[Morden South railway station|Morden South]], [[St Helier railway station|St Helier]] and [[West Sutton railway station|West Sutton]] were not part of the UERL's plan.}} The tube extension itself opened in 1926 with seven new stations all designed by [[Charles Holden]] in a modern style.
-The Edgware extension used plans dating back to 1901 for the [[Charing Cross, Euston and Hampstead Railway#Hampstead Heath controversy|Edgware and Hampstead Railway]] (E&HR)<ref name=gazette_2>{{London Gazette |issue=27380 |date=26 November 1901 |page=8200}}</ref> which the UERL's subsidiary, the [[London Electric Railway]], had taken over in 1912.{{sfn|Horne|2009|p=28}} It extended the CCE&HR line from its terminus at Golders Green to Edgware in two stages: to [[Hendon Central tube station|Hendon Central]] in 1923 and to [[Edgware tube station|Edgware]] in 1924.{{sfn|Rose|2016}}{{sfn|Horne|2009|p=29}} The line crossed open countryside and ran mostly on viaduct from Golders Green to Brent and then on the surface, apart from a short tunnel north of Hendon Central.{{sfn|Horne|2009|p=29}} Five new stations were built to pavilion-style designs by [[Stanley Heaps]], the UERL's architect, stimulating the rapid northward expansion of suburban developments in the following years.{{sfn|Day|Reed|2010|p=91}}
-====Morden Extension====
+Owing to the complicated nature of the resulting line, it became known as the Morden–Edgware line, although a number of alternative [[portmanteau]] names were mooted in the fashion of the [[Baker Street and Waterloo Railway]] becoming the Bakerloo line, such as "Edgmor", "Mordenware", "Medgeway" and "Edgmorden" lines.{{sfn|Wolmar|2005|p=225}}
-The engineering of the Morden extension of the C&SLR from Clapham Common to Morden was more demanding; it runs in tunnels to a point just north of [[Morden tube station|Morden station]] which was constructed in a cutting. The line then goes under the wide station forecourt and public road outside the station to the depot. The extension was initially [[Sutton Underground Line Proposal|planned]] to continue to [[Sutton, London|Sutton]]<ref name=gazette_3>{{London Gazette |issue=32770 |date=24 November 1922 |pages=8314–8315}}</ref> over part of the route for the unbuilt [[Wimbledon and Sutton Railway]] (in which the UERL held a stake) but agreements were made with [[Southern Railway (Great Britain)|Southern Railway]] to end the extension at Morden. Southern Railway built the surface line from Wimbledon to Sutton in the 1930s via South Merton and St. Helier.{{#tag:ref|The stations that the C&SLR were to serve on the W&SR, would not have included all those subsequently built by the Southern Railway. [[Morden tube station (District Railway)|South Morden]] (not built), [[Sutton Common railway station|Sutton Common]], [[Cheam tube station|Cheam]] (not built) and [[Sutton (Surrey) railway station|Sutton]], would have been served, but [[Morden South railway station|Morden South]], [[St Helier railway station|St Helier]] and [[West Sutton railway station|West Sutton]] were not part of the UERL's plan.|group="nb"}} The tube extension itself opened in 1926 with seven new stations all designed by [[Charles Holden]] in a modern style. Originally Stanley Heaps was to design the stations, but after seeing the designs [[Frank Pick]] (Assistant Joint Manager of the UERL) decided that Holden should take over the project.<ref>{{cite web |title=Underground Journeys: Moving Underground |url=http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/MovingUnderground/MovingUnderground.aspx |work=architecture.com |publisher=[[Royal Institute of British Architects]] |access-date=20 February 2011 |archive-url=https://web.archive.org/web/20110504024751/http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/MovingUnderground/MovingUnderground.aspx |archive-date=4 May 2011}}</ref>
-With the exception of Morden and [[Clapham South tube station|Clapham South]], where more land was available, the new stations were built on confined corner sites at main road junctions in areas that had been already developed. Holden made good use of this limited space and designed striking buildings. The street-level structures are of white [[Portland stone]] with tall double-height ticket halls, with the London Underground roundel made up in coloured glass panels in large glazed screens. The stone columns framing the glass screens are surmounted by a capital formed as a three-dimensional version of the roundel. The large expanses of glass above the entrances ensure that the ticket halls are bright and lit from within at night, creating a welcoming feel.<ref>{{cite web |title=Underground Journeys: South Wimbledon |url=http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/MovingUnderground/SouthWimbledon.aspx |work=architecture.com |publisher=[[Royal Institute of British Architects]] |access-date=20 February 2011 |archive-url=https://web.archive.org/web/20110707161011/http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/MovingUnderground/SouthWimbledon.aspx |archive-date=7 July 2011}}</ref> The first and last new stations on the extension, Clapham South and Morden, include a parade of shops and were designed with structures capable of being built above (like many of the earlier [[central London]] stations). Clapham South was extended upwards soon after its construction with a block of apartments; Morden was extended upwards in the 1960s with a block of offices. All the stations on the extension, except Morden itself, are Grade II [[listed building]]s.
+After the UERL and the [[Metropolitan Railway]] (MR) became unified under the [[London Passenger Transport Board]] (LPTB) in 1933, the MR's [[Northern City Line|Great Northern & City Railway]] subsidiary, which ran mostly underground from Moorgate to [[Finsbury Park station|Finsbury Park]], transferred management to the Morden–Edgware line, branding itself as the Northern City line.
-===Great Northern & City Railway===
+===<span class="anchor" id="The Northern Heights plan"></span> Northern Heights plan===
-After the UERL and the [[Metropolitan Railway]] became part of the new unified [[London Passenger Transport Board]] in 1933, the MR's subsidiary the [[Northern City Line|Great Northern & City Railway]] became part of the Underground as the Northern City Line. It ran underground from Moorgate to [[Finsbury Park station|Finsbury Park]]. In preparation for the Northern Heights Plan it was operated as part of the Northern line, although it was never connected to the rest of the line.
-===Naming===
-The resulting line became known as the Morden–Edgware line, although a number of alternative names were also mooted in the fashion of the contraction of Baker Street & Waterloo Railway to "Bakerloo", such as "Edgmor", "Mordenware", "Medgeway" and "Edgmorden".{{sfn|Wolmar|2005|p=225}} It was eventually named the ''Northern line'' from 28 August 1937,<ref>Rails through the Clay; Croome & Jackson; London; 2nd ed; 1993; p228</ref> reflecting the planned addition of the Northern Heights lines.<ref name="new name">{{cite journal |date=25 August 1937 |title=London Tubes' New Names – Northern and Central Lines |journal=The Times |issue=47772 |page=12 |url=http://infotrac.galegroup.com/itw/infomark/708/539/29061067w16/purl=rc1_TTDA_0_CS203370777&dyn=52!xrn_7_0_CS203370777&hst_1?sw_aep=kccl |access-date=18 May 2009}}{{Subscription required}}</ref>
-==={{anchor|The Northern Heights plan}} Northern Heights plan===
-[[File:Northern Heights diagram.png|thumb|Line map of the abandoned Northern Heights plan]]
-[[File:Northern Line Northern Heights Extension sign.jpg|thumb|Sign displaying the route of the Northern Heights extension]]
 <!-- This section and its anchor is linked from [[Closed London Underground stations]] and from [[Charing Cross, Euston and Hampstead Railway]] -->
 {{redirect|Northern Heights|the neighbourhood in Sudbury, Ontario|Urban neighbourhoods of Sudbury#Donovan/Northern Heights|the condominium/mall in Yellowknife, Northwest Territories|Centre Square Mall}}
 {{Broader|Edgware, Highgate and London Railway|topic=the detailed history}}
-In June 1935 the LPTB announced the [[New Works Programme]], an ambitious plan to expand the Underground network which included the integration of a complex of existing [[London and North Eastern Railway]] (LNER) lines north of [[Highgate]] through the Northern Heights. These lines, built in the 1860s and 1870s by the [[Edgware, Highgate and London Railway]] (EH&LR) and its successors, ran from Finsbury Park to [[Edgware railway station|Edgware]] via Highgate, with branches to [[Alexandra Palace railway station (Muswell Hill branch)|Alexandra Palace]] and [[High Barnet tube station|High Barnet]]. The line taken over would be extended beyond Edgware to [[Brockley Hill tube station|Brockley Hill]], [[Elstree South tube station|Elstree South]] and [[Bushey Heath tube station|Bushey Heath]] with a new depot at [[Aldenham Works|Aldenham]]. The extension's route was that planned for the unbuilt [[Watford and Edgware Railway]] (W&ER), using rights obtained from the earlier purchase of the W&ER (which had long intended an extension of the EH&LR Edgware route towards [[Watford]]). This also provided the potential for further extension in the future; [[Bushey]]'s town planners reserved space in Bushey village for a future station and Bushey Heath station's design was revised several times to ensure this option would remain available in the future.
+[[File:Northern Heights diagram.png|thumb|Line map of the abandoned Northern Heights plan]]
+[[File:Northern Line Northern Heights Extension sign.jpg|thumb|Sign displaying the route of the Northern Heights extension]]
+Following the formation of the LPTB, in June 1935 the organisation proposed the [[New Works Programme]], an ambitious plan to expand the Underground network in response to London's growing suburban population and relieve congestion on the existing [[Steam locomotive|steam-operated]] suburban lines. In the case of the Morden–Edgware, these were the [[London and North Eastern Railway]] (LNER) suburban lines north of Highgate, built in the 1860s and 1870s by the [[Edgware, Highgate and London Railway]] (EH&LR) and its successors, running from Finsbury Park to [[Edgware railway station|Edgware]] via Highgate, with branches to [[Alexandra Palace railway station (Muswell Hill branch)|Alexandra Palace]] and [[High Barnet tube station|High Barnet]].
+The Morden–Edgware line's project, known as the Northern Heights plan owing to the high ground in north London,<ref>{{Cite web |url=https://trainstobeyond.com/northern-heights/ |title=The Northern Heights |website=Trains to Beyond |author=Chris Sutton}}</ref> involved [[Railway electrification in Great Britain#London Underground|fourth-rail electrification]] of the surface lines and the [[Double-track railway|double-tracking]] of the single-line section between [[Finchley Central tube station|Finchley (Church End)]] and Edgware. The Northern Heights plan also called for the construction of three new linking sections of track: between the Northern City line and new surface level platforms at Finsbury Park; a deep-level tunnel from Archway to [[East Finchley tube station|East Finchley]]; and a diversion of the Mill Hill branch to the LPTB's Edgware station.<ref name="Northern Wastes" />
+In addition, the Edgware branch would also be extended beyond the terminus to a site at [[Bushey Heath tube station|Bushey Heath]], the LPTB having retained planning rights of the unbuilt [[Watford and Edgware Railway]], which had long intended an extension of the EH&LR's Edgware branch towards [[Watford]]. [[Aldenham Works|A new depot at Aldenham]], just before the Bushey Heath terminus, would also be constructed to facilitate the housing of additional trains.<ref name="Beyond Edgware">{{Cite book |title=By Tube Beyond Edgware |author=Tony Beard |year=2002 |publisher=Capital Transport}}</ref> As a result of the project's name, the Morden–Edgware line was renamed as the Northern line.<ref>{{Cite web |url=https://www.ltmuseum.co.uk/collections/stories/transport/northern-line |website=London Transport Museum |title=The Northern line}}</ref><ref>Rails through the Clay; Croome & Jackson; London; 2nd ed; 1993; p228</ref><ref name="new name">{{cite journal |date=25 August 1937 |title=London Tubes' New Names – Northern and Central Lines |journal=The Times |issue=47772 |page=12 |url=http://infotrac.galegroup.com/itw/infomark/708/539/29061067w16/purl=rc1_TTDA_0_CS203370777&dyn=52!xrn_7_0_CS203370777&hst_1?sw_aep=kccl |access-date=18 May 2009}}{{Subscription required}}</ref>
-The project involved [[Railway electrification in Great Britain|electrification]] of the surface lines (operated by steam trains at the time), the doubling of the original single-line section between [[Finchley Central tube station|Finchley Central]] and the proposed junction with the Edgware branch of the Northern line, and the construction of three new linking sections of track: a connection between Northern City Line and Finsbury Park station on the surface; an extension from Archway to the LNER line near [[East Finchley tube station|East Finchley]] via new deep-level platforms below [[Highgate tube station|Highgate station]]; and a short diversion from just before the LNER's Edgware station to the Underground's station of the same name.
+Work began on the initial stages of the extensions in 1936, as did that on Bushey Heath following its authorisation in 1937, with completion projected by 1941.<ref name="Northern Wastes">{{Cite book |title=Northern Wastes |author1=Jim Blake |author2=Jonathan James |year=1987 |publisher=Platform 10}}</ref> The tunnelling northwards from Archway was the first element to be completed and an initial service to the rebuilt East Finchley station commenced on 3 July 1939, though trains skipped the deep-level platforms at Highgate until its fitout was completed by 19 January 1941.
-====Intended service levels====
+Further progress was disrupted by the start of the [[World War II|Second World War]] in September 1939; however enough development had been made to complete the electrification of the High Barnet branch, over which tube services started on 14 April 1940, and the single-track LNER line to Edgware being electrified as far as [[Mill Hill East tube station|Mill Hill East]], reopening as a tube service on 18 May 1941 to serve the nearby [[Inglis Barracks]]. The partially-complete depot at Aldenham was converted into an aircraft factory, constructing [[Handley Page Halifax]] bombers as part of the war effort.<ref name="Beyond Edgware" /><ref>{{Cite web |url=https://content.tfl.gov.uk/halifax-plane-production-by-lptb-during-wwii.pdf |title=Halifax Plane Production by LPTB during WWII |website=Transport for London |date=November 2020}}</ref> Other work on the extension that were eventually halted during the Second World War included the construction of a viaduct at [[Brockley Hill tube station|Brockley Hill]] and a tunnel near [[Elstree South tube station|Elstree South]] which started in June 1939, the laying of a second line as far as [[Mill Hill (The Hale) railway station|Mill Hill (The Hale)]] and the construction of its second platform.<ref name="Mill Hill (The Hale)">{{Cite web |url=http://www.disused-stations.org.uk/m/mill_hill_hale/index.shtml |website=Disused Stations |title=Mill Hill (The Hale) |author=Nick Catford}}</ref>
-The peak-hour service pattern was to be 21 trains an hour each way on the High Barnet branch north of Camden Town, 14 of them via the Charing Cross branch and seven via the Bank branch. 14 would have continued on beyond Finchley Central, seven each on the High Barnet and Edgware branches. An additional seven trains an hour would have served the High Barnet branch but continued via Highgate High-Level and Finsbury Park to Moorgate, a slightly shorter route to the city. It does not seem to have been intended to run through trains to the ex-Northern City branch from Edgware via Finchley Central. Seven trains an hour would have served the Alexandra Palace branch, to/from Moorgate via Highgate High-Level. In addition to the 14 through trains described the ex-Northern City branch would have had 14 four-car shuttle trains an hour.
-====Progress of works====
+After the war, much of the area beyond Edgware was made part of the [[Metropolitan Green Belt]] that largely prevented the anticipated residential development, thus the potential demand for services from Bushey Heath vanished.<ref name="Beyond Edgware" /> A compromise was offered to make Brockley Hill the line's terminus and retain a link to Aldenham Depot,<ref name="Northern Wastes" /> but the Bushey Heath extension was cancelled in 1950.<ref>{{Cite book |title=The London Transport Golden Jubilee Book |author1=Oliver Green |author2=John Reed |year=1983 |publisher=The Daily Telegraph}}</ref> Although efforts were made to complete Aldenham Depot as an Underground facility, from December 1947 it was modified for use as a heavy repair works of [[Bus manufacturing#Bodywork|bus bodies]], supposedly temporarily until Aldenham was required for railway purposes. Following the extension's cancellation, the depot was converted into an overhaul facility for buses, serving this purpose until 1986.<ref>{{Cite web |url=https://content.tfl.gov.uk/research-guide-no-33-aldenham-bus-works.pdf |title=Research Guide No 33: Aldenham Bus Works |date=27 April 2016 |website=Transport for London}}</ref>
-Work began in the late 1930s and was in progress on all fronts by the outbreak of the [[World War II|Second World War]]. The tunnelling northwards from the original Highgate station (now [[Archway tube station|Archway]]) had been completed, and the service to the rebuilt surface station at [[East Finchley tube station|East Finchley]] started on 3 July 1939 but without the opening of the intermediate (new) Highgate Station at the site of the LNER's station of the same name. Further progress was disrupted by the start of the war; however enough development had been made to complete the electrification of the [[High Barnet tube station|High Barnet]] branch onwards from East Finchley (over which tube services started on 14 April 1940) and the new deep-level [[Highgate tube station|Highgate]] station opened on 19 January 1941. The single track LNER line to Edgware was electrified as far as [[Mill Hill East tube station|Mill Hill East]], including the [[Dollis Brook Viaduct]], opening as a tube service on 18 May 1941 to serve the barracks there thus forming the Northern line as it is today. The new depot at Aldenham had already been built and was used to build [[Handley Page Halifax|Halifax]] bombers. Work on the other elements of the plan was suspended late in 1939.
-Work on the extension from Edgware to Bushey Heath including work on a viaduct and a tunnel started in June 1939, but was stopped after war broke out.{{sfn|Beard|2002|pp=90–92}} After the war, the area beyond Edgware was made part of the [[Metropolitan Green Belt]], largely preventing the anticipated residential development in the area, and the potential demand for services from Bushey Heath thus vanished. Passenger numbers also dropped on the then-[[British Rail|BR]]'s Mill Hill and Alexandra Palace branches, so it was useless to electrify them. Available funds were directed towards completing the eastern extension of the [[Central line (London Underground)|Central line]] instead, and the Northern Heights plan was dropped on 9 February 1954. Aldenham depot was converted into an overhaul facility for buses.
+The introduction of electric services to High Barnet and Mill Hill East undermined passenger numbers on the remaining LNER-operated lines. Consequently, passenger services to Mill Hill (The Hale) and Edgware, having been suspended in September 1939 to allow works to be completed, never resumed<ref name="Mill Hill (The Hale)" /> and the Alexandra Palace branch line via the surface platforms at Highgate ceased to passenger traffic on 3 July 1954, with the last of the Northern Heights plans also being dropped that year.<ref name="Northern Wastes" /> Available funds were directed towards completing the eastern extension of the [[Central line (London Underground)|Central line]] instead. Freight-hauled mainline trains continued to run alongside Northern line services until 1964.<ref>{{Cite web |url=http://disused-stations.org.uk/e/edgware/index.shtml |title=Edgware (GNR) |website=Disused Stations |author=Nick Catford}}</ref> Tickets were still being sold to and from Mill Hill (The Hale) until the late 1960s, with passengers being directed onto [[London Buses route 240|the 240 bus]] to connect with the Underground.<ref name="Mill Hill (The Hale)" />
-The implemented service from High Barnet branch gave good access both to the [[West End of London|West End]] and the [[City of London|City]]. This appears to have undermined traffic on the Alexandra Palace branch, still run with steam haulage to [[King's Cross St Pancras tube station|Kings Cross]] via Finsbury Park, as Highgate (low-level) was but a short bus ride away and car traffic was much lighter than it would become later. Consequently, the line from Finsbury Park to Muswell Hill and Alexandra Palace via the surface platforms at Highgate was closed altogether to passenger traffic in 1954.{{citation needed|date=May 2020}} This contrasts with the decision to electrify the Epping-Ongar branch of the Central line, another remnant of the New Works programme, run as a tube-train shuttle from 1957. A local pressure group, the Muswell Hill Metro Group, campaigns to reopen this route as a light-rail service.{{citation needed|date=May 2020}} So far there is no sign of movement on this issue: the route, now the [[Parkland Walk]], is highly valued by walkers and cyclists, and suggestions in the 1990s that it could, in part, become a road were met with fierce opposition.{{citation needed|date=May 2020}} Another pressure group has proposed using the track bed further north, as part of the [[North and West London Light Railway]].{{citation needed|date=May 2020}} The connection between [[Drayton Park railway station|Drayton Park]] and the surface platforms at Finsbury Park was opened in 1976, when the Northern City Line became part of [[British Rail]].
+The connection between [[Drayton Park railway station|Drayton Park]] and the surface platforms at Finsbury Park, which gave access onto the Finsbury Park–Highgate line, was retained for rolling stock transfers between the Northern City and Northern line until 1970, the incomplete electrification on this section necessitating stock being hauled by [[London Underground battery–electric locomotives|battery-electric locomotives]].<ref name="Northern Wastes" /> Passenger services commenced on the Finsbury Park link in 1976, when the Northern City line transferred to [[British Rail]] ownership.
-=== 1990s refurbishment and upgrade ===
+=== Recent developments ===
 [[File:Northern line cab.JPG|thumb|Close-up of a [[High Barnet tube station|High Barnet]]-bound Northern line [[London Underground 1995 Stock|1995 stock]] cab|alt=]]
-In the 1980s, a southern extension of the line to [[Peckham]] was proposed, as part of a review of potential extensions of Underground lines. The proposal was not proceeded with.<ref>{{cite web|date=1988|title=Strategic Review 1988 – New Lines and Extensions – Northern Line Southern Extension |url=https://www.whatdotheyknow.com/request/244458/response/618034/attach/5/LUL%20Strategic%20Review%201988%20New%20lines%20and%20extensions%20Northern%20Line.pdf?cookie_passthrough=1|url-status=live|website=What Do They Know |publisher=London Underground|access-date=27 September 2021|archive-date=9 September 2021|archive-url=https://web.archive.org/web/20210909142639/https://www.whatdotheyknow.com/request/244458/response/618034/attach/5/LUL%20Strategic%20Review%201988%20New%20lines%20and%20extensions%20Northern%20Line.pdf?cookie_passthrough=1}}</ref>
+In a separate proposal to the New Works Programme, the LPTB looked into extending the Northern line south of Morden to [[North Cheam]] as late as 1944 alongside a relief line from Kennington to Epsom via Morden.<ref>{{Cite book |title=London's Underground Suburbs |author1=Dennis Edwards |author2=Ron Pigram |year=1988 |publisher=Bloomsbury}}</ref> Further proposals included building additional tunnels between Kennington and [[Tooting Broadway tube station|Tooting Broadway]] to relieve congestion, with alternative duplication suggested between Golders Green and Waterloo.<ref>{{Cite |url=https://archive.org/details/railways00609132/page/n23/mode/2up |title=Report to the Minister of War Transport |date=21 January 1946 |author=Railway (London Plan) Committee 1944 |pp=17-18}}</ref> In the 1980s, an extension of the Northern line to [[Peckham Rye railway station|Peckham Rye]] and [[Streatham Hill railway station|Streatham Hill]] was proposed as part of a review of potential extensions of Underground lines.<ref>{{cite web|date=1988|title=Strategic Review 1988 – New Lines and Extensions – Northern Line Southern Extension |url=https://www.whatdotheyknow.com/request/244458/response/618034/attach/5/LUL%20Strategic%20Review%201988%20New%20lines%20and%20extensions%20Northern%20Line.pdf?cookie_passthrough=1|url-status=live|website=What Do They Know |publisher=London Underground|access-date=27 September 2021|archive-date=9 September 2021|archive-url=https://web.archive.org/web/20210909142639/https://www.whatdotheyknow.com/request/244458/response/618034/attach/5/LUL%20Strategic%20Review%201988%20New%20lines%20and%20extensions%20Northern%20Line.pdf?cookie_passthrough=1}}</ref>
+Between 1989 and 1992, [[Angel tube station]] was rebuilt with a new northbound tunnel alongside the existing station platforms which were widened to become the new southbound  platform, replacing the old narrow platforms which by then had become a safety hazard with increased passenger ridership.<ref name="Clive">{{Cite web |url=https://www.davros.org/rail/culg/northern.html |website=Clive's UndergrounD Line Guides |title=Northern Line}}</ref> A similar project was undertaken at Euston in the 1960s in conjunction with the construction of the [[Victoria line]]<ref name="Clive" /> and at Bank in the early 2020s in order to increase station capacity and improve accessibility.<ref>{{Cite web |url=https://www.newcivilengineer.com/latest/bank-station-upgrade-northern-line-reopens-after-blockade-success-16-05-2022/ |title=Bank station upgrade: Northern line reopens after blockade success |website=New Civil Engineer |author=Catherine Moore |date=16 May 2022}}</ref><ref>{{Cite web |url=https://tfl.gov.uk/info-for/media/press-releases/2022/october/next-phase-of-vital-upgrade-of-bank-station-completes-with-the-opening-of-a-new-interchange-route-between-the-northern-line-and-dlr |website=Transport for London |title=Next phase of vital upgrade of Bank station completes, with the opening of a new interchange route between the Northern line and DLR |date=13 October 2022}}</ref>
+By the early 1990s, the line had deteriorated due to years of under-investment and the use of old [[London Underground rolling stock|rolling stock]], most of which dated back to the early 1960s.<ref>{{cite web |title=Northern Line (Hansard, 17 March 1994) |url=https://api.parliament.uk/historic-hansard/commons/1994/mar/17/northern-line |website=api.parliament.uk |access-date=27 May 2020 |archive-date=11 May 2021 |archive-url=https://web.archive.org/web/20210511074812/https://api.parliament.uk/historic-hansard/commons/1994/mar/17/northern-line |url-status=live}}</ref> The line gained the nickname "Misery Line" due to its perceived unreliability.<ref>{{cite web |archive-url=https://ghostarchive.org/varchive/youtube/20211211/i2O-w4vhaf4 |archive-date=11 December 2021 |last=Pearce |first=Mike |date=22 June 1989 |title=Northern Line driverless trains |url=https://www.youtube.com/watch?v=i2O-w4vhaf4 |via=YouTube |publisher=[[Thames Television]], [[Thames News]]}}{{cbignore}}</ref><ref name="misery1">{{cite news |title=Call for action on Northern Line |url=https://news.bbc.co.uk/2/hi/uk_news/england/london/4334700.stm |publisher=[[BBC News]] |date=12 October 2005 |access-date=10 June 2008 |archive-date=1 September 2007 |archive-url=https://web.archive.org/web/20070901010932/http://news.bbc.co.uk/1/hi/england/london/4334700.stm |url-status=live}}</ref> In 1995, a comprehensive refurbishment of the line began – including track replacement, power upgrades, station modernisation (such as [[Mornington Crescent tube station|Mornington Crescent]]) and the replacement of older rolling stock with new [[London Underground 1995 Stock|1995 Stock]] thanks to a [[public–private partnership]] deal with [[Alstom]].<ref>{{cite web|title=Tubular hell |url=http://www.independent.co.uk/news/tubular-hell-1281922.html|date=6 January 1997 |website=The Independent|location=London |access-date=27 May 2020|archive-date=15 May 2021 |archive-url=https://web.archive.org/web/20210515191000/https://www.independent.co.uk/news/tubular-hell-1281922.html|url-status=live}}</ref><ref>{{cite web |date=2000 |title=Northern line modernisation |url=http://www.londontransport.co.uk/underground/n_mod.htm |archive-url=https://web.archive.org/web/20000616133201/http://www.londontransport.co.uk/underground/n_mod.htm |archive-date=16 June 2000 |access-date=14 March 2021 |website=London Transport}}</ref>
-By the early 1990s, the line had deteriorated due to years of under-investment and the use of old [[London Underground rolling stock|rolling stock]], most of which dated back to the early 1960s.<ref>{{cite web |title=Northern Line (Hansard, 17 March 1994) |url=https://api.parliament.uk/historic-hansard/commons/1994/mar/17/northern-line |website=api.parliament.uk |access-date=27 May 2020 |archive-date=11 May 2021 |archive-url=https://web.archive.org/web/20210511074812/https://api.parliament.uk/historic-hansard/commons/1994/mar/17/northern-line |url-status=live}}</ref> The line gained the nickname "Misery Line" due to its perceived unreliability.<ref>{{cite web |archive-url=https://ghostarchive.org/varchive/youtube/20211211/i2O-w4vhaf4 |archive-date=11 December 2021 |last=Pearce |first=Mike |date=22 June 1989 |title=Northern Line driverless trains |url=https://www.youtube.com/watch?v=i2O-w4vhaf4 |via=YouTube |publisher=[[Thames Television]], [[Thames News]]}}{{cbignore}}</ref><ref name="misery1">{{cite news |title=Call for action on Northern Line |url=http://news.bbc.co.uk/1/hi/england/london/4334700.stm |publisher=[[BBC News]] |date=12 October 2005 |access-date=10 June 2008 |archive-date=1 September 2007 |archive-url=https://web.archive.org/web/20070901010932/http://news.bbc.co.uk/1/hi/england/london/4334700.stm |url-status=live}}</ref> In 1995, a comprehensive refurbishment of the line began – including track replacement, power upgrades, station modernisation (such as [[Mornington Crescent tube station|Mornington Crescent]]) and the replacement of older rolling stock with new [[London Underground 1995 Stock|1995 Stock]] thanks to a [[public–private partnership]] deal with [[Alstom]].<ref>{{cite web|title=Tubular hell |url=http://www.independent.co.uk/news/tubular-hell-1281922.html|date=6 January 1997 |website=The Independent|location=London |access-date=27 May 2020|archive-date=15 May 2021 |archive-url=https://web.archive.org/web/20210515191000/https://www.independent.co.uk/news/tubular-hell-1281922.html|url-status=live}}</ref><ref>{{cite web |date=2000 |title=Northern line modernisation |url=http://www.londontransport.co.uk/underground/n_mod.htm |archive-url=https://web.archive.org/web/20000616133201/http://www.londontransport.co.uk/underground/n_mod.htm |archive-date=16 June 2000 |access-date=14 March 2021 |website=London Transport}}</ref>
+The Northern line was originally scheduled to switch to [[automatic train operation]] in 2012, using the same [[SelTrac]] S40 system<ref name=thereg-20160809>{{cite news |last=Corfield |first=Gareth |title=London's 'automatic' Tube trains suffered 750 computer failures last year |url=https://www.theregister.co.uk/2016/08/09/london_underground_trains_stopped_750_times_automatic_train_operation_failure/ |url-status=live |newspaper=The Register |date=9 August 2016 |access-date=9 August 2016 |archive-url=https://web.archive.org/web/20160809093739/http://www.theregister.co.uk/2016/08/09/london_underground_trains_stopped_750_times_automatic_train_operation_failure/ |archive-date=9 August 2016}}</ref> as used since 2009 on the [[Jubilee line]] and for a number of years on the [[Docklands Light Railway]].<ref name="Tube Lines">{{cite press release |title=Network Tests for New Signalling Systems |url=http://www.tubelines.com/news/releases/200602/20050824.aspx |publisher=[[Tube Lines]] |date=24 August 2005 |archive-url=https://web.archive.org/web/20080105201220/http://www.tubelines.com/news/releases/200602/20050824.aspx |archive-date=5 January 2008}}</ref> Originally the work was to follow on from the Jubilee line so as to benefit from the experience of installing it there, but that project was not completed until spring 2011. Work on the Northern line was contracted to be completed before the [[2012 Summer Olympics|2012 Olympics]]. It was then undertaken in-house, and TfL predicted the upgrade would be complete by the end of 2014.<ref>{{cite web |url=http://www.tfl.gov.uk/assets/downloads/corporate/Part-1-Item06-Operational-Financial-Peformance-and-Investment-Programme-Reports-Q3-2012-13.pdf |publisher=Transport for London |date=6 February 2013 |title=Operational and Financial Performance Report and Investment Programme Report – Third Quarter, 2012/13 |access-date=1 March 2013 |archive-date=30 April 2013 |archive-url=https://web.archive.org/web/20130430154333/http://www.tfl.gov.uk/assets/downloads/corporate/Part-1-Item06-Operational-Financial-Peformance-and-Investment-Programme-Reports-Q3-2012-13.pdf |url-status=live}}</ref> The first section of the line (West Finchley to High Barnet) was transferred to the new signalling system on 26 February 2013<ref>{{cite press release |url=http://www.tfl.gov.uk/corporate/media/newscentre/archive/27303.aspx |publisher=Transport for London |date=26 February 2013 |title=Northern line upgrade one step closer}}</ref> and the line became fully automated on 1 June 2014, with the Chalk Farm to Edgware via Golders Green section being the last part of the line to switch to ATO.<ref>{{cite web|url=https://www.london.gov.uk/moderngov/documents/s40260/Transport%20Commitments%20Appendix%201.pdf |archive-url=https://web.archive.org/web/20210511105907/https://www.london.gov.uk/moderngov/documents/s40260/Transport%20Commitments%20Appendix%201.pdf |archive-date=2021-05-11 |url-status=live|title=Mayor of London – Transport Commitments}}</ref><ref>{{cite web|url=https://www.railengineer.co.uk/2015/05/08/lu-northern-line-goes-cbtc/|title=LU Northern line goes CBTC|last=Kessell|first=Clive|access-date=5 October 2019}}{{dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes}}</ref>
-== Recent developments ==
+Since the mid-autumn of 2016,<ref name=":3">{{cite web |url=https://tfl.gov.uk/campaign/tube-improvements/what-we-are-doing/night-tube |title=The Night Tube |publisher=Transport for London |access-date=28 September 2016 |archive-date=21 August 2020 |archive-url=https://web.archive.org/web/20200821161701/https://tfl.gov.uk/campaign/tube-improvements/what-we-are-doing/night-tube |url-status=live}}</ref> a 24-hour "[[Night Tube]]" service has run on Friday and Saturday nights from Edgware and High Barnet to Morden via the Charing Cross branch; service is suspended on the Bank branch during these times.<ref>{{cite web |url=https://tfl.gov.uk/campaign/tube-improvements/the-future-of-the-tube/night-tube |title=The Night Tube |date=n.d. |publisher=Transport for London |access-date=24 October 2015 |archive-date=11 July 2015 |archive-url=https://web.archive.org/web/20150711150816/https://tfl.gov.uk/campaign/tube-improvements/the-future-of-the-tube/night-tube |url-status=live}}</ref> Trains run every eight minutes between Morden and Camden Town and up to every 16 minutes on the Edgware and High Barnet branches. Labour disputes delayed the planned start date of September 2015.<ref>{{cite news |url=https://www.theguardian.com/uk-news/2015/aug/27/london-night-tube-plan-suspended |title=London night tube plan suspended |first=Gwyn |last=Topham |work=The Guardian |location=London |date=27 August 2015 |access-date=15 December 2016 |archive-date=1 January 2017 |archive-url=https://web.archive.org/web/20170101093815/https://www.theguardian.com/uk-news/2015/aug/27/london-night-tube-plan-suspended |url-status=live}}</ref>
-Throughout the 2000s, no plans were considered for extending the Northern line, as the PPP to upgrade the Underground did not include provision for line extensions within the PPP contracts.<ref>{{cite web |title=Details of Tube modernisation plans unveiled |url=http://www.tubelines.com/news/releases/200602/20030108.aspx |website=Tube Lines |date=8 January 2003 |access-date=8 March 2021 |archive-url=https://web.archive.org/web/20060519094016/http://www.tubelines.com/news/releases/200602/20030108.aspx |archive-date=19 May 2006}}</ref><ref>{{cite web |last1=Shawcross |first1=Valerie |author1-link=Val Shawcross |last2=Livingstone |first2=Ken |author2-link=Ken Livingstone |title=Transport Plan – Southward Extensions |url=https://www.london.gov.uk/questions/2005/0820 |url-status=live |date=7 March 2005 |access-date=29 March 2021 |website=Mayor's Question Time |archive-url=https://web.archive.org/web/20210909142647/https://www.london.gov.uk/questions/2005/0820 |archive-date=9 September 2021}}</ref> The Northern line was originally scheduled to switch to [[automatic train operation]] in 2012, using the same [[SelTrac]] S40 system<ref name=thereg-20160809>{{cite news |last=Corfield |first=Gareth |title=London's 'automatic' Tube trains suffered 750 computer failures last year |url=https://www.theregister.co.uk/2016/08/09/london_underground_trains_stopped_750_times_automatic_train_operation_failure/ |url-status=live |newspaper=The Register |date=9 August 2016 |access-date=9 August 2016 |archive-url=https://web.archive.org/web/20160809093739/http://www.theregister.co.uk/2016/08/09/london_underground_trains_stopped_750_times_automatic_train_operation_failure/ |archive-date=9 August 2016}}</ref> as used since 2009 on the [[Jubilee line]] and for a number of years on the [[Docklands Light Railway]].<ref name="Tube Lines">{{cite press release |title=Network Tests for New Signalling Systems |url=http://www.tubelines.com/news/releases/200602/20050824.aspx |publisher=[[Tube Lines]] |date=24 August 2005 |archive-url=https://web.archive.org/web/20080105201220/http://www.tubelines.com/news/releases/200602/20050824.aspx |archive-date=5 January 2008}}</ref> Originally the work was to follow on from the Jubilee line so as to benefit from the experience of installing it there, but that project was not completed until spring 2011. Work on the Northern line was contracted to be completed before the [[2012 Summer Olympics|2012 Olympics]]. It was then undertaken in-house, and TfL predicted the upgrade would be complete by the end of 2014.<ref>{{cite web |url=http://www.tfl.gov.uk/assets/downloads/corporate/Part-1-Item06-Operational-Financial-Peformance-and-Investment-Programme-Reports-Q3-2012-13.pdf |publisher=Transport for London |date=6 February 2013 |title=Operational and Financial Performance Report and Investment Programme Report – Third Quarter, 2012/13 |access-date=1 March 2013 |archive-date=30 April 2013 |archive-url=https://web.archive.org/web/20130430154333/http://www.tfl.gov.uk/assets/downloads/corporate/Part-1-Item06-Operational-Financial-Peformance-and-Investment-Programme-Reports-Q3-2012-13.pdf |url-status=live}}</ref> The first section of the line (West Finchley to High Barnet) was transferred to the new signalling system on 26 February 2013<ref>{{cite press release |url=http://www.tfl.gov.uk/corporate/media/newscentre/archive/27303.aspx |publisher=Transport for London |date=26 February 2013 |title=Northern line upgrade one step closer}}</ref> and the line became fully automated on 1 June 2014, with the Chalk Farm to Edgware via Golders Green section being the last part of the line to switch to ATO.<ref>{{cite web|url=https://www.london.gov.uk/moderngov/documents/s40260/Transport%20Commitments%20Appendix%201.pdf |archive-url=https://web.archive.org/web/20210511105907/https://www.london.gov.uk/moderngov/documents/s40260/Transport%20Commitments%20Appendix%201.pdf |archive-date=2021-05-11 |url-status=live|title=Mayor of London – Transport Commitments}}</ref><ref>{{cite web|url=https://www.railengineer.co.uk/2015/05/08/lu-northern-line-goes-cbtc/|title=LU Northern line goes CBTC|last=Kessell|first=Clive|access-date=5 October 2019}}{{dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes}}</ref>
 In January 2018, Transport for London announced that it would double the period during which it runs peak evening services in the central London section to tackle overcrowding. There would now be 24 trains per hour on both central London branches and the northern branches, as well as 30 trains per hour on the Kennington to Morden section between 5{{nbsp}}pm and 7{{nbsp}}pm.<ref name="cityam">{{cite news |url=http://www.cityam.com/279628/northern-line-passengers-get-quicker-and-more-frequent |title=Northern Line passengers to get quicker and more frequent journeys as TfL boosts services to tackle crowding on busiest Tube line |newspaper=[[City A.M.]] |location=London |date=29 January 2018 |access-date=29 January 2018 |first=Rebecca |last=Smith |url-status=dead |archive-url=https://web.archive.org/web/20180130064220/http://www.cityam.com/279628/northern-line-passengers-get-quicker-and-more-frequent |archive-date=30 January 2018}}</ref>
-===24-hour weekend service===
+=== Battersea extension ===
-Since the mid-autumn of 2016,<ref name=":3">{{cite web |url=https://tfl.gov.uk/campaign/tube-improvements/what-we-are-doing/night-tube |title=The Night Tube |publisher=Transport for London |access-date=28 September 2016 |archive-date=21 August 2020 |archive-url=https://web.archive.org/web/20200821161701/https://tfl.gov.uk/campaign/tube-improvements/what-we-are-doing/night-tube |url-status=live}}</ref> a 24-hour "[[Night Tube]]" service has run on Friday and Saturday nights from Edgware and High Barnet to Morden via the Charing Cross branch; service is suspended on the Bank branch during these times.<ref>{{cite web |url=https://tfl.gov.uk/campaign/tube-improvements/the-future-of-the-tube/night-tube |title=The Night Tube |date=n.d. |publisher=Transport for London |access-date=24 October 2015 |archive-date=11 July 2015 |archive-url=https://web.archive.org/web/20150711150816/https://tfl.gov.uk/campaign/tube-improvements/the-future-of-the-tube/night-tube |url-status=live}}</ref> Trains run every eight minutes between Morden and Camden Town and every 15/16 minutes between Camden Town and Edgware/High Barnet. Labour disputes delayed the planned start date of September 2015.<ref>{{cite news |url=https://www.theguardian.com/uk-news/2015/aug/27/london-night-tube-plan-suspended |title=London night tube plan suspended |first=Gwyn |last=Topham |work=The Guardian |location=London |date=27 August 2015 |access-date=15 December 2016 |archive-date=1 January 2017 |archive-url=https://web.archive.org/web/20170101093815/https://www.theguardian.com/uk-news/2015/aug/27/london-night-tube-plan-suspended |url-status=live}}</ref>
-===Battersea extension===
 {{main|Northern line extension to Battersea}}
-In September 2021, the Northern line was extended to serve the redevelopment of [[Battersea Power Station]]. Partially funded by private developers, the £1.2bn project extended the Charing Cross branch of the line for {{convert|3.2|km|mi|abbr=in}} from [[Kennington tube station|Kennington]] to Battersea Power Station,<ref name=":0">{{cite news|last=Collier|first=Hatty|date=8 November 2017|title=Tunnelling work to extend Tube's Northern Line to Battersea completed|work=Evening Standard|location=London|url=https://www.standard.co.uk/news/transport/northern-line-extension-tunnelling-work-on-12bn-extension-to-battersea-completed-ahead-of-2020-a3685746.html|access-date=22 January 2018|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109041335/https://www.standard.co.uk/news/transport/northern-line-extension-tunnelling-work-on-12bn-extension-to-battersea-completed-ahead-of-2020-a3685746.html|url-status=live}}</ref> with an intermediate stop at [[Nine Elms tube station|Nine Elms.]]<ref name=":1">{{cite press release|url=https://tfl.gov.uk/info-for/media/press-releases/2014/november/northern-line-extension-to-battersea-gets-go-ahead|date=12 November 2014|title=Northern line extension to Battersea gets go-ahead|publisher=Transport for London|access-date=22 January 2018|archive-date=26 May 2021|archive-url=https://web.archive.org/web/20210526082500/https://tfl.gov.uk/info-for/media/press-releases/2014/november/northern-line-extension-to-battersea-gets-go-ahead|url-status=live}}</ref><ref name=":2">{{cite web|title=Northern line extension |url=https://tfl.gov.uk/travel-information/improvements-and-projects/northern-line-extension|access-date=22 January 2018|publisher=Transport for London|archive-date=29 July 2019|archive-url=https://web.archive.org/web/20190729235927/https://tfl.gov.uk/travel-information/improvements-and-projects/northern-line-extension |url-status=live}}</ref> Approved by Wandsworth Council in 2010<ref>{{cite press release|title=Battersea Power Station scheme approved |url=http://www.wandsworth.gov.uk/news/article/10136/battersea_power_station_scheme_approved|publisher=[[London Borough of Wandsworth]]|date=11 November 2010|access-date=12 November 2010|archive-url=https://web.archive.org/web/20131014095827/http://www.wandsworth.gov.uk/news/article/10136/battersea_power_station_scheme_approved|archive-date=14 October 2013}}</ref> and TfL in 2014,<ref name=":1" /> the construction of the line began in 2015. Tunnelling for the project was completed in 2017,<ref name=":0" /> and the extension opened on 20 September 2021.<ref>{{cite web |last1=Prynn |first1=Jonathan|last2=Sleigh|first2=Sophia|date=21 December 2018|title=TfL under fire as Battersea Tube extension is delayed |url=https://www.standard.co.uk/news/transport/tfl-under-fire-as-battersea-tube-extension-is-delayed-by-miscalculations-a4023386.html|url-status=live|archive-url=https://web.archive.org/web/20201023202028/https://www.standard.co.uk/news/transport/tfl-under-fire-as-battersea-tube-extension-is-delayed-by-miscalculations-a4023386.html|archive-date=23 October 2020|access-date=3 February 2021|website=Evening Standard|location=London}}</ref><ref name="BBC-Battersea">{{cite news|date=20 September 2021|title=Northern line extension: Two new Tube stations open|publisher=BBC News|url=https://www.bbc.com/news/uk-england-london-58621491|access-date=20 September 2021|archive-date=20 September 2021|archive-url=https://web.archive.org/web/20210920073208/https://www.bbc.com/news/uk-england-london-58621491|url-status=live}}</ref> Provision has been made for a future extension to [[Clapham Junction railway station]].<ref>{{cite news|last=Henderson|first=Jamie|date=23 June 2013 |title=Clapham Junction next for Northern Line says London Assembly member|newspaper=Wandsworth Guardian|url=http://www.wandsworthguardian.co.uk/news/10501385.Clapham_Junction_next_for_Northern_Line_says_London_Assembly_member/|access-date=12 January 2014|archive-date=24 December 2013|archive-url=https://web.archive.org/web/20131224115148/http://www.wandsworthguardian.co.uk/news/10501385.Clapham_Junction_next_for_Northern_Line_says_London_Assembly_member/|url-status=live}}</ref>
+Throughout the 2000s, no plans were considered for extending the Northern line, as the PPP contracts to upgrade the Underground did not include provision for line extensions.<ref>{{cite web |title=Details of Tube modernisation plans unveiled |url=http://www.tubelines.com/news/releases/200602/20030108.aspx |website=Tube Lines |date=8 January 2003 |access-date=8 March 2021 |archive-url=https://web.archive.org/web/20060519094016/http://www.tubelines.com/news/releases/200602/20030108.aspx |archive-date=19 May 2006}}</ref><ref>{{cite web |last1=Shawcross |first1=Valerie |author1-link=Val Shawcross |last2=Livingstone |first2=Ken |author2-link=Ken Livingstone |title=Transport Plan – Southward Extensions |url=https://www.london.gov.uk/questions/2005/0820 |url-status=live |date=7 March 2005 |access-date=29 March 2021 |website=Mayor's Question Time |archive-url=https://web.archive.org/web/20210909142647/https://www.london.gov.uk/questions/2005/0820 |archive-date=9 September 2021}}</ref> This prolonged period without an extension ultimately changed when the Northern line was extended to serve the redevelopment of [[Battersea Power Station]] in 2021. Partially funded by private developers, the £1.2bn project extended the Charing Cross branch of the line for {{convert|3.2|km|mi|abbr=in}} from [[Kennington tube station|Kennington]] to [[Battersea Power Station tube station|Battersea Power Station]],<ref name=":0">{{cite news|last=Collier|first=Hatty|date=8 November 2017|title=Tunnelling work to extend Tube's Northern Line to Battersea completed|work=Evening Standard|location=London|url=https://www.standard.co.uk/news/transport/northern-line-extension-tunnelling-work-on-12bn-extension-to-battersea-completed-ahead-of-2020-a3685746.html|access-date=22 January 2018|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109041335/https://www.standard.co.uk/news/transport/northern-line-extension-tunnelling-work-on-12bn-extension-to-battersea-completed-ahead-of-2020-a3685746.html|url-status=live}}</ref> with an intermediate stop at [[Nine Elms tube station|Nine Elms.]]<ref name=":1">{{cite press release|url=https://tfl.gov.uk/info-for/media/press-releases/2014/november/northern-line-extension-to-battersea-gets-go-ahead|date=12 November 2014|title=Northern line extension to Battersea gets go-ahead|publisher=Transport for London|access-date=22 January 2018|archive-date=26 May 2021|archive-url=https://web.archive.org/web/20210526082500/https://tfl.gov.uk/info-for/media/press-releases/2014/november/northern-line-extension-to-battersea-gets-go-ahead|url-status=live}}</ref><ref name=":2">{{cite web|title=Northern line extension |url=https://tfl.gov.uk/travel-information/improvements-and-projects/northern-line-extension|access-date=22 January 2018|publisher=Transport for London|archive-date=29 July 2019|archive-url=https://web.archive.org/web/20190729235927/https://tfl.gov.uk/travel-information/improvements-and-projects/northern-line-extension |url-status=live}}</ref> Approved by Wandsworth Council in 2010<ref>{{cite press release|title=Battersea Power Station scheme approved |url=http://www.wandsworth.gov.uk/news/article/10136/battersea_power_station_scheme_approved|publisher=[[London Borough of Wandsworth]]|date=11 November 2010|access-date=12 November 2010|archive-url=https://web.archive.org/web/20131014095827/http://www.wandsworth.gov.uk/news/article/10136/battersea_power_station_scheme_approved|archive-date=14 October 2013}}</ref> and TfL in 2014,<ref name=":1" /> construction began in 2015. Tunnelling for the project was completed in 2017,<ref name=":0" /> and the extension opened on 20 September 2021.<ref>{{cite web |last1=Prynn |first1=Jonathan|last2=Sleigh|first2=Sophia|date=21 December 2018|title=TfL under fire as Battersea Tube extension is delayed |url=https://www.standard.co.uk/news/transport/tfl-under-fire-as-battersea-tube-extension-is-delayed-by-miscalculations-a4023386.html|url-status=live|archive-url=https://web.archive.org/web/20201023202028/https://www.standard.co.uk/news/transport/tfl-under-fire-as-battersea-tube-extension-is-delayed-by-miscalculations-a4023386.html|archive-date=23 October 2020|access-date=3 February 2021|website=Evening Standard|location=London}}</ref><ref name="BBC-Battersea">{{cite news|date=20 September 2021|title=Northern line extension: Two new Tube stations open|publisher=BBC News|url=https://www.bbc.com/news/uk-england-london-58621491|access-date=20 September 2021|archive-date=20 September 2021|archive-url=https://web.archive.org/web/20210920073208/https://www.bbc.com/news/uk-england-london-58621491|url-status=live}}</ref> Provision has been made for a future extension to [[Clapham Junction railway station|Clapham Junction]].<ref>{{cite news|last=Henderson|first=Jamie|date=23 June 2013 |title=Clapham Junction next for Northern Line says London Assembly member|newspaper=Wandsworth Guardian|url=http://www.wandsworthguardian.co.uk/news/10501385.Clapham_Junction_next_for_Northern_Line_says_London_Assembly_member/|access-date=12 January 2014|archive-date=24 December 2013|archive-url=https://web.archive.org/web/20131224115148/http://www.wandsworthguardian.co.uk/news/10501385.Clapham_Junction_next_for_Northern_Line_says_London_Assembly_member/|url-status=live}}</ref>
 ==Services==
@@ Line 139: / Line 128: @@
 *2 tph from Mill Hill East to Morden via Bank
-This service pattern provides 20 tph between Finchley Central and High Barnet, 4 tph between Finchley Central and Mill Hill East, 16 tph between Kennington and Battersea Power Station and 22 tph everywhere else on the line except between Kennington and Morden, between Camden Town and Finchley Central and on the Edgware branch where there will be 24 tph.
+This service pattern provides 20 tph between Finchley Central and High Barnet, 4 tph between Finchley Central and Mill Hill East, 16 tph between Kennington and Battersea Power Station and 22 tph everywhere else on the line except between Kennington and Morden, between Camden Town and Finchley Central and on the Edgware branch where there are 24 tph.
 === Off-peak ===
@@ Line 154: / Line 143: @@
 === Night ===
-Since 2016, the Northern line has operated [[Night Tube]] services on Friday and Saturday nights between the Edgware and High Barnet termini and Morden, via the Charing Cross branch only. Trains run every 15 minutes on each of the northern branches, combining to give eight trains per hour between Camden Town and Morden. There is no Night Tube service on the Mill Hill East, Bank, or Battersea branches.<ref name=":3" />
+Since 2016, the Northern line has operated [[Night Tube]] services on Friday and Saturday nights between the Edgware and High Barnet termini and Morden via the Charing Cross branch only. Trains run every 15 minutes on each of the northern branches, combining to give eight trains per hour between Camden Town and Morden. There is no Night Tube service on the Mill Hill East, Bank or Battersea branches.<ref name=":3" />
 *4 tph from High Barnet to Morden via Charing Cross
@@ Line 354: / Line 343: @@
 ===Rolling stock===
 [[File:1995ts at Finchley Central.jpg|thumb|A [[High Barnet tube station|High Barnet]]-bound Northern line train arriving at [[Finchley Central tube station|Finchley Central]]|alt=]]
-When the line opened, it was served by [[London Underground 1906 Stock|1906 Stock]]. This was replaced by [[London Underground Standard Stock|Standard stock]] which was in turn replaced by [[1938 stock]] as part of the New Works Programme, later supplemented with identical [[London Underground 1949 Stock|1949 Stock]]. When the [[Piccadilly line]] was extended to [[Heathrow Airport]] in the 1970s, its [[London Underground 1959 Stock|1959 Stock]] and [[London Underground 1956 Stock|1956 Stock]] (prototypes of the 1959 Stock) trains were transferred to the Northern line. As there were not enough 1956 and 1959 Stock trains to replace the Northern line's 1938 Stock fleet, they were supplemented with newly built [[London Underground 1972 Stock|1972 Mark 1 Stock]] trains, which all served the line at the same time. 1972 Mark 2 stock trains also ran on this line until going to the Jubilee line; they were then moved to the Bakerloo line, where they remain in service. The few 1956 Stock trains were briefly replaced by [[London Underground 1962 Stock|1962 Stock]] transferred from the [[Central line (London Underground)|Central line]] in 1995, before the entire Northern line fleet was replaced with [[London Underground 1995 Stock|1995 Stock]] between 1998 and 2000.
+When the line opened, it was served by [[London Underground 1906 Stock|1906 Stock]]. This was replaced by [[London Underground Standard Stock|Standard stock]] which was in turn replaced by [[1938 stock]] as part of the New Works Programme, later supplemented with identical [[London Underground 1949 Stock|1949 Stock]]. When the [[Piccadilly line]] was extended to [[Heathrow Airport]] in the 1970s, its [[London Underground 1959 Stock|1959 Stock]] and [[London Underground 1956 Stock|1956 Stock]] (prototypes of the 1959 Stock) trains were transferred to the Northern line. As there were not enough 1956 and 1959 Stock trains to replace the Northern line's 1938 Stock fleet, they were supplemented with newly built [[London Underground 1972 Stock|1972 Mark 1 Stock]] trains, which all served the line at the same time. 1972 Mark 2 stock trains also ran on this line until going to the [[Jubilee line]]; they were then moved to the [[Bakerloo line]], where they remain in service. By 1986, increasing unreliability of 1959 stock trains meant there were regularly too few trains to run a full peak service.  Five 1938 stock trains, newly retired from the Bakerloo Line, were overhauled and returned to the Northern Line to serve another two years until further 1972 stock could be transferred from the Jubilee Line, which was moving to [[London Underground 1983 Stock|1983 stock]].  The few 1956 Stock trains were briefly replaced by [[London Underground 1962 Stock|1962 Stock]] transferred from the [[Central line (London Underground)|Central line]] in 1995, before the entire Northern line fleet was replaced with [[London Underground 1995 Stock|1995 Stock]] between 1998 and 2000.
 Today, all Northern line trains consist of 1995 Stock in the Underground livery of red, white and blue. In common with the other deep-level lines, the trains are the smaller of the two [[loading gauge]]s used on the system. 1995 stock has automated announcements and quick-close doors.{{citation needed|date=May 2020}} If the [[#Future|proposed split]] of the line takes place (initial estimates of 2018 having been abandoned to focus on completion of the Battersea and Nine Elms extension work), 19 new trains will be added to the existing fleet of 106 trains,<ref>Abbot 2010, pp. 57–58.</ref> though additional trains beyond the extra 19 trains may be required to provide a full service for the new Battersea extension.
@@ Line 369: / Line 358: @@
 ===Northern line split===
-Since the 2000s, TfL has aspired to split the Northern line into two separate routes.<ref name=":02">{{cite CiteSeerX |date=November 2006|title=Transport 2025: Transport vision for a growing world city |citeseerx=10.1.1.135.5972|quote=A segregation of services would deliver simpler service patterns on the line. This will allow more trains to be run through both the West End and City branches – enabling 30tph services on the central London branches. This will provide roughly 25 per cent extra capacity and crowding relief on these busy sections. With the core infrastructure being capable of supporting these service patterns, the main requirements are some additional trains (and stabling) and station capacity improvements at Camden Town.}}</ref><ref>{{cite news |url=https://www.standard.co.uk/news/northern-line-service-divided-in-312m-bid-to-end-overcrowding-6468560.html |author=Lydall, Ross |title=Northern line service divided in £312m bid to end overcrowding |newspaper=Evening Standard|location=London |date=12 May 2010 |access-date=21 March 2013 |archive-date=15 December 2013 |archive-url=https://web.archive.org/web/20131215224824/http://www.standard.co.uk/news/northern-line-service-divided-in-312m-bid-to-end-overcrowding-6468560.html |url-status=live}}</ref> Running trains between all combinations of branches and the two central sections, as at present, means only 24 trains an hour can run through each of the central sections at peak times, because merging trains have to wait for each other at the junctions at [[Camden Town tube station|Camden Town]] and [[Kennington tube station|Kennington]].<ref name="TwinPeaks">{{cite web|title=Twin Peaks: Timetable Changes on the Northern Line|url=https://www.londonreconnections.com/2015/northern-line-timetable-for-the-future/|website=London Reconnections|date=14 January 2015|access-date=5 June 2017|archive-date=15 June 2017|archive-url=https://web.archive.org/web/20170615132515/http://www.londonreconnections.com/2015/northern-line-timetable-for-the-future/|url-status=live}}</ref> Completely segregating the routes could allow 36 trains an hour on all parts of the line, increasing capacity by around 25%.<ref name=":02" /><ref name="TwinPeaks"/>
+Since the 2000s, TfL has aspired to split the Northern line into two routes.<ref name=":02">{{cite CiteSeerX |date=November 2006|title=Transport 2025: Transport vision for a growing world city |citeseerx=10.1.1.135.5972|quote=A segregation of services would deliver simpler service patterns on the line. This will allow more trains to be run through both the West End and City branches – enabling 30tph services on the central London branches. This will provide roughly 25 per cent extra capacity and crowding relief on these busy sections. With the core infrastructure being capable of supporting these service patterns, the main requirements are some additional trains (and stabling) and station capacity improvements at Camden Town.}}</ref><ref>{{cite news |url=https://www.standard.co.uk/news/northern-line-service-divided-in-312m-bid-to-end-overcrowding-6468560.html |author=Lydall, Ross |title=Northern line service divided in £312m bid to end overcrowding |newspaper=Evening Standard|location=London |date=12 May 2010 |access-date=21 March 2013 |archive-date=15 December 2013 |archive-url=https://web.archive.org/web/20131215224824/http://www.standard.co.uk/news/northern-line-service-divided-in-312m-bid-to-end-overcrowding-6468560.html |url-status=live}}</ref> Running trains between all combinations of branches and the two central sections, as at present, means only 24 trains an hour can run through each of the central sections at peak times, because merging trains have to wait for each other at the junctions at [[Camden Town tube station|Camden Town]] and [[Kennington tube station|Kennington]].<ref name="TwinPeaks">{{cite web|title=Twin Peaks: Timetable Changes on the Northern Line|url=https://www.londonreconnections.com/2015/northern-line-timetable-for-the-future/|website=London Reconnections|date=14 January 2015|access-date=5 June 2017|archive-date=15 June 2017|archive-url=https://web.archive.org/web/20170615132515/http://www.londonreconnections.com/2015/northern-line-timetable-for-the-future/|url-status=live}}</ref> Completely segregating the routes could allow 36 trains an hour on all parts of the line, increasing capacity by around 25%.<ref name=":02" /><ref name="TwinPeaks"/>
 TfL has already separated the Charing Cross and Bank branches during off-peak periods; however, four trains per hour still run to and from Morden via Charing Cross in the peak; the northern branches to Edgware and High Barnet cannot be separated until Camden Town station is upgraded to cope with the numbers of passengers changing trains.<ref name=":4">{{cite web|date=6 May 2013|title=We Need To Talk About Camden: The Future of the Northern Line|url=https://www.londonreconnections.com/2013/we-need-to-talk-about-camden/|access-date=13 September 2021|website=London Reconnections|archive-date=23 September 2021|archive-url=https://web.archive.org/web/20210923125828/https://www.londonreconnections.com/2013/we-need-to-talk-about-camden/|url-status=live}}</ref> The extension to Battersea would allow the [[Charing Cross tube station|Charing Cross]] branch to terminate at Battersea Power Station.<ref>{{cite web|date=15 May 2010|title=Permanent split for the Northern line|url=https://www.yourlocalguardian.co.uk/news/8166289.permanent-split-for-the-northern-line/|url-status=live|access-date=13 September 2021|website=Your Local Guardian |archive-date=14 August 2020|archive-url=https://web.archive.org/web/20200814222805/https://www.yourlocalguardian.co.uk/news/8166289.permanent-split-for-the-northern-line/}}</ref><ref name=":412">{{cite web|date=4 August 2015|title=Plans to split Northern Line in two move forward another step|url=https://www.railtechnologymagazine.com/Rail-News/plans-to-split-northern-line-in-two-move-forward-another-step|url-status=live|access-date=13 September 2021|website=Rail Technology Magazine|archive-date=13 September 2021|archive-url=https://web.archive.org/web/20210913212544/https://www.railtechnologymagazine.com/Rail-News/plans-to-split-northern-line-in-two-move-forward-another-step}}</ref>
-The proposed split of the Northern line would require Camden Town station to be expanded and upgraded, as the station is already severely overcrowded at weekend peak times, and a split would increase the number of passengers wishing to change trains at the station.<ref name=":412"/><ref name="upcap12">{{cite web|date=2017|title=Improving capacity at Camden Town station|url=https://consultations.tfl.gov.uk/tube/camden-town-station-upgrade/|access-date=20 February 2018|publisher=Transport for London|archive-date=21 February 2018|archive-url=https://web.archive.org/web/20180221100254/https://consultations.tfl.gov.uk/tube/camden-town-station-upgrade/|url-status=live}} Detailed report, with updated timeline etc.</ref><ref name=":4" /> In 2005, London Underground failed to secure planning permission for a comprehensive upgrade plan for Camden Town tube station that would have involved demolition of the existing station entrance and several other surface-level buildings, all within a [[Conservation area (United Kingdom)|conservation area]].<ref>{{cite web|date=25 January 2006|title=Camden Town Redevelopment|url=http://www.alwaystouchout.com/project/62|access-date=30 June 2008|publisher=Alwaystouchout.com|archive-date=11 November 2007|archive-url=https://web.archive.org/web/20071111081104/http://www.alwaystouchout.com/project/62|url-status=live}}</ref><ref name="2ndTimeLucky">{{cite web|last1=Bull|first1=John|date=14 October 2015|title=Second Time Lucky: Rebuilding Camden Town Station|url=https://www.londonreconnections.com/2015/second-time-lucky-rebuilding-camden-town-station/|website=London Reconnections|access-date=5 June 2017|archive-date=28 June 2017|archive-url=https://web.archive.org/web/20170628175351/http://www.londonreconnections.com/2015/second-time-lucky-rebuilding-camden-town-station/|url-status=live}}</ref> New redevelopment plans were first announced in 2013 by TfL, which proposed avoiding the existing station entrance and the conservation area by building a second entrance and interchange tunnels to the north, mostly on the site of a subsequently vacated [[infant school]].<ref name="upcap12"/> In 2018, plans to upgrade and rebuild Camden Town station were placed indefinitely on hold, due to TfL's financial situation.<ref>{{cite news |last=Topham |first=Gwyn |date=11 December 2018 |title=Major tube upgrades shelved as TfL struggles to balance books |work=The Guardian |location=London |url=https://www.theguardian.com/uk-news/2018/dec/11/major-tube-upgrades-shelved-as-tfl-struggles-to-balance-books |access-date=26 January 2020 |archive-date=26 December 2019 |archive-url=https://web.archive.org/web/20191226092007/https://www.theguardian.com/uk-news/2018/dec/11/major-tube-upgrades-shelved-as-tfl-struggles-to-balance-books |url-status=live}}</ref> {{As of|2024}}, TfL said they still "aspire" to split the line. A partial separation was proposed in which all trains from Morden would operate via Bank, while those starting at Kennington (or Battersea) would serve the Charing Cross branch. The High Barnet and Edgware branches would remain served by trains from both routes.<ref name="f763">{{cite web |last=Cooke |first=Alex |date=14 April 2024 |title=TfL still 'aspires' to split Tube line to increase capacity by 20k |url=https://www.mylondon.news/news/transport/tfl-northern-line-london-underground-28980969 |access-date=16 March 2025 |website=My London}}</ref>
+The proposed split of the Northern line would require Camden Town station to be expanded and upgraded, as the station is already severely overcrowded at weekend peak times, and a split would increase the number of passengers wishing to change trains at the station.<ref name=":412"/><ref name="upcap12">{{cite web|date=2017|title=Improving capacity at Camden Town station|url=https://consultations.tfl.gov.uk/tube/camden-town-station-upgrade/|access-date=20 February 2018|publisher=Transport for London|archive-date=21 February 2018|archive-url=https://web.archive.org/web/20180221100254/https://consultations.tfl.gov.uk/tube/camden-town-station-upgrade/|url-status=live}} Detailed report, with updated timeline etc.</ref><ref name=":4" /> In 2005, London Underground failed to secure planning permission for a comprehensive upgrade plan for Camden Town tube station that would have involved demolition of the existing station entrance and several other surface-level buildings, all within a [[Conservation area (United Kingdom)|conservation area]].<ref>{{cite web|date=25 January 2006|title=Camden Town Redevelopment|url=http://www.alwaystouchout.com/project/62|access-date=30 June 2008|publisher=Alwaystouchout.com|archive-date=11 November 2007|archive-url=https://web.archive.org/web/20071111081104/http://www.alwaystouchout.com/project/62|url-status=dead}}</ref><ref name="2ndTimeLucky">{{cite web|last1=Bull|first1=John|date=14 October 2015|title=Second Time Lucky: Rebuilding Camden Town Station|url=https://www.londonreconnections.com/2015/second-time-lucky-rebuilding-camden-town-station/|website=London Reconnections|access-date=5 June 2017|archive-date=28 June 2017|archive-url=https://web.archive.org/web/20170628175351/http://www.londonreconnections.com/2015/second-time-lucky-rebuilding-camden-town-station/|url-status=live}}</ref> New redevelopment plans were first announced in 2013 by TfL, which proposed avoiding the existing station entrance and the conservation area by building a second entrance and interchange tunnels to the north, mostly on the site of a subsequently vacated [[infant school]].<ref name="upcap12"/> In 2018, plans to upgrade and rebuild Camden Town station were placed indefinitely on hold, due to TfL's financial situation.<ref>{{cite news |last=Topham |first=Gwyn |date=11 December 2018 |title=Major tube upgrades shelved as TfL struggles to balance books |work=The Guardian |location=London |url=https://www.theguardian.com/uk-news/2018/dec/11/major-tube-upgrades-shelved-as-tfl-struggles-to-balance-books |access-date=26 January 2020 |archive-date=26 December 2019 |archive-url=https://web.archive.org/web/20191226092007/https://www.theguardian.com/uk-news/2018/dec/11/major-tube-upgrades-shelved-as-tfl-struggles-to-balance-books |url-status=live}}</ref> {{As of|2024}}, TfL said they still "aspire" to split the line. A partial separation was proposed in which all trains from Morden would operate via Bank, while those starting at Kennington (or Battersea) would serve the Charing Cross branch. The High Barnet and Edgware branches would remain served by trains from both routes.<ref name="f763">{{cite web |last=Cooke |first=Alex |date=14 April 2024 |title=TfL still 'aspires' to split Tube line to increase capacity by 20k |url=https://www.mylondon.news/news/transport/tfl-northern-line-london-underground-28980969 |access-date=16 March 2025 |website=My London}}</ref>
 ==Incidents and accidents==
-In October 2003, a train derailed at [[Camden Town tube station|Camden Town]].<ref>{{cite news |date=19 October 2003 |title=Second Tube train derailed |publisher=BBC News |url=http://news.bbc.co.uk/2/hi/uk_news/england/london/3204794.stm |access-date=27 May 2020 |archive-date=25 July 2020 |archive-url=https://web.archive.org/web/20200725100727/http://news.bbc.co.uk/2/hi/uk_news/england/london/3204794.stm |url-status=live}}</ref> Although no one was hurt, points, signals and carriages were damaged. Concern was raised about the safety of the Tube, given the derailment at [[Chancery Lane tube station|Chancery Lane]] earlier in 2003.<ref>{{cite news |date=25 January 2003 |title=Thirty hurt after Tube crash |publisher=BBC News |url=http://news.bbc.co.uk/2/hi/uk_news/england/2694361.stm |access-date=27 May 2020 |archive-date=30 April 2020 |archive-url=https://web.archive.org/web/20200430185255/http://news.bbc.co.uk/2/hi/uk_news/england/2694361.stm |url-status=live}}</ref> A joint report by the Underground and its maintenance contractor [[Tube Lines]] concluded that poor [[track geometry]] was the main cause, and therefore extra friction arising out of striations (scratches) on a newly installed set of points had allowed the leading wheel of the last carriage to climb the rail and derail. The track geometry at the derailment site is a very tight bend and tight tunnel bore, which precludes the normal solution for this sort of geometry of canting the track by raising the height of one rail relative to the other.<ref>{{cite magazine |title=Track design flaws may have led to Camden Town Tube derailment |url=https://www.newcivilengineer.com/archive/track-design-flaws-may-have-led-to-camden-town-tube-derailment-04-12-2003/ |date=4 December 2003 |magazine=New Civil Engineer |access-date=27 May 2020}}</ref>
+In October 2003, a train derailed at [[Camden Town tube station|Camden Town]].<ref>{{cite news |date=19 October 2003 |title=Second Tube train derailed |publisher=BBC News |url=https://news.bbc.co.uk/2/hi/uk_news/england/london/3204794.stm |access-date=27 May 2020 |archive-date=25 July 2020 |archive-url=https://web.archive.org/web/20200725100727/http://news.bbc.co.uk/2/hi/uk_news/england/london/3204794.stm |url-status=live}}</ref> Although no one was hurt, points, signals and carriages were damaged. Concern was raised about the safety of the Tube, given the derailment at [[Chancery Lane tube station|Chancery Lane]] earlier in 2003.<ref>{{cite news |date=25 January 2003 |title=Thirty hurt after Tube crash |publisher=BBC News |url=https://news.bbc.co.uk/1/hi/england/2694361.stm |access-date=27 May 2020 |archive-date=30 April 2020 |archive-url=https://web.archive.org/web/20200430185255/http://news.bbc.co.uk/2/hi/uk_news/england/2694361.stm |url-status=live}}</ref> A joint report by the Underground and its maintenance contractor [[Tube Lines]] concluded that poor [[track geometry]] was the main cause, and therefore extra friction arising out of striations (scratches) on a newly installed set of points had allowed the leading wheel of the last carriage to climb the rail and derail. The track geometry at the derailment site is a very tight bend and tight tunnel bore, which precludes the normal solution for this sort of geometry of canting the track by raising the height of one rail relative to the other.<ref>{{cite magazine |title=Track design flaws may have led to Camden Town Tube derailment |url=https://www.newcivilengineer.com/archive/track-design-flaws-may-have-led-to-camden-town-tube-derailment-04-12-2003/ |date=4 December 2003 |magazine=New Civil Engineer |access-date=27 May 2020}}</ref>
 In August 2010, a defective [[Railgrinder|rail grinding]] train caused disruption on the Charing Cross branch, after it travelled four miles in 13 minutes without a driver. The train was being towed to the depot after becoming faulty. At [[Archway tube station|Archway station]], the defective train became detached and ran driverless until coming to a stop at an incline near [[Warren Street tube station|Warren Street station]]. This caused morning rush-hour services to be suspended on this branch. All passenger trains were diverted via the Bank branch, with several not stopping at stations until they were safely on the Bank branch.<ref>{{cite news |date=13 August 2010 |title=Runaway train on London Tube's Northern Line |publisher=BBC News |url=https://www.bbc.co.uk/news/uk-england-10964766 |access-date=18 August 2010 |archive-date=17 August 2010 |archive-url=https://web.archive.org/web/20100817235330/http://www.bbc.co.uk/news/uk-england-10964766 |url-status=live}}</ref><ref>{{cite tech report |title=Runaway of an engineering train from Highgate 13 August 2010 |number=09-2011 |institution=RAIB |year=2011}}</ref>
@@ Line 384: / Line 373: @@
 * The [[Bloc Party]] song "Waiting For the 7.18" references the Northern line as "the loudest".<ref>{{cite web|url=http://www.blocparty.net/waitingforthe718.html|title=BlocParty.net – Waiting for the 7.18|archive-url=https://web.archive.org/web/20130415094528/http://www.blocparty.net/waitingforthe718.html|archive-date=15 April 2013}}</ref>
 * As part of a series of twelve books tied to the twelve lines of the London Underground, A ''Northern Line Minute'' focuses on the Northern line.<ref>{{cite web |url= http://www.penguin.co.uk/books/a-northern-line-minute/9781846145315/ |title=A Northern Line Minute, The Northern Line by William Leith |publisher=Penguin |date=7 March 2013 |archive-url= https://web.archive.org/web/20150403093024/https://www.penguin.co.uk/books/a-northern-line-minute/9781846145315/ |archive-date=3 April 2015 |access-date=28 August 2017}}</ref>
+* The [[New Vaudeville Band|New Vaudeville Band's]] 1967 song "Finchley Central" ("On Tour" in the US) mentions several stations on the line.<ref>{{cite web |author1=Alan Charles Klein |author2=Geoffrey Stephens |title=New Vaudeville Band: Finchley Central |url=https://lyrics.lyricfind.com/lyrics/new-vaudeville-band-finchley-central |website=LyricFind |publisher=Peermusic Publishing |access-date=15 June 2025 |date=1967}}</ref>
 * The [[Nick Drake]] song "Parasite" references the Northern Line.<ref>{{cite web|url=http://www.nickdrake.com/parasite_lyrics.html|title=Parasite|access-date=9 November 2015|archive-date=24 October 2015|archive-url=https://web.archive.org/web/20151024091819/http://www.nickdrake.com/parasite_lyrics.html|url-status=live}}</ref>
 * The 1982 [[Robyn Hitchcock]] song "Fifty Two Stations" begins, "There's fifty-two stations on the Northern Line/None of them is yours, one of them is mine."<ref>{{cite web|url=https://genius.com/Robyn-hitchcock-fifty-two-stations-lyrics|title=Fifty Two Stations|access-date=13 August 2018|archive-date=14 August 2018|archive-url=https://web.archive.org/web/20180814002027/https://genius.com/Robyn-hitchcock-fifty-two-stations-lyrics|url-status=live}}</ref>
@@ Line 451: / Line 441: @@
 * [[London deep-level shelters]], most of which are under Northern line stations
 * [[Tunnels underneath the River Thames]]
-==Explanatory footnotes==
-{{notelist}}
 ==References==
 ===Notes===
-{{reflist|group=nb}}
+{{notelist}}
 ===Citations===
@@ Line 485: / Line 472: @@
 {{Commons category|Northern Line}}
 {{Attached KML|display=title,inline}}
-* [http://londonist.com/2009/05/google_street_view_a_journey_along.php Above-ground route of line from Morden to Edgware], constructed from Google StreetView
+*{{Official website}}
 * [https://web.archive.org/web/20110707160249/http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/UndergroundJourneys.aspx Architectural history of London Underground during 1920-30s] from the [[Royal Institute of British Architects]]
 ** [https://web.archive.org/web/20110707161133/http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/FitnessforPurpose/OldStreet.aspx Old Street, Angel and Stockwell stations]