North London line


The North London line is a railway line which passes through the inner suburbs of London, England between Richmond in the south-west and Stratford in the east, avoiding central London. Its route is a rough semicircle.
Although much of it originated as part of the North London Railway, the current route is the result of a series of amalgamations, closures and reopenings, and has a mix of third-rail and overhead electrical power supply. It remains heavily used by freight services in addition to the Mildmay line passenger service on the London Overground. Between Richmond and Gunnersbury, London Underground's District line shares tracks with the Mildmay line; the entire route is owned and maintained by Network Rail.
TfL took over the line in 2007 and introduced new stock as well as putting the line on the Tube map. It closed for four months in 2010 between and and had a reduced service for another year to allow platform extensions and signalling upgrades.
In November 2024, the North London and West London sections of the London Overground were named the Mildmay line and are coloured light blue on the Tube map.

History

Formation

The North London line between Richmond and North Woolwich derived from five connecting sections which were opened over 25 years from 1846:
The line from Broad Street to Kew Bridge and Richmond was electrified by the LNWR in 1916 on the fourth-rail DC system.
In 1944, passenger services on the NLR Poplar branch ceased. Freight traffic continued on the branch to the docks on the Isle of Dogs until 1980. The trackbed of the southern part of the branch, from Poplar to Bow, was used for the Docklands Light Railway branch to Stratford.
The service was listed for closure in the 1963 Beeching Report, with losses claimed as being £69,000 per year. It was saved after a huge campaign. The line was Grant Aided under the Transport Act 1968 and came under threat when the Conservative Government of 1970–71 proposed to reduce Grant Aid funding. That threat, eventually lifted, led to the founding of a new campaign group, the North London Line Committee, which tried to work with British Rail management to promote the service.
In 1979, the North Woolwich to Stratford service was extended to Camden Road as the Crosstown Linkline service, using the same Cravens-built diesel multiple unit trains. There were no intermediate stations until, in 1980, Hackney Wick was opened, near the site of the former Victoria Park station and Hackney Central was re-opened; then Homerton re-opened in 1985. New platforms were built at West Ham for interchange with the adjacent Underground station.
The part of the line between the West London and East Coast Main Lines was proposed in the mid-1990s to be used for Regional Eurostar services, which would travel from the lines into Waterloo International station to points north of London. A proposed link to Heathrow Airport would have also used the line between Willesden Junction and Acton. Regional Eurostar was eventually cancelled.

Rolling stock

The line was originally operated by steam-hauled trains which were replaced after electrification by London and North Western Railway EMUs built from 1914 and augmented by later EMUs built in the 1930s by the London, Midland and Scottish Railway. These had all been replaced by the early 1960s with dedicated short-wheelbase trains built by the Southern Region at Eastleigh from 1957 which were later designated by British Railways as Class 501. These were succeeded by Southern Region Class 416 EMU for a short period, these units being allocated to Selhurst depot in south London. Class 416 trains were in turn succeeded by Class 313 EMUs, which worked the route until 2010 when London Overground introduced Class 378 Capitalstar four-car dual-voltage electric trains compatible with both 750 V DC third-rail and 25 kV AC overhead power sources, and all of these units were by 2017 operating in 5-car formations to address the additional demand on the route.

Closures

In 1986, Broad Street station closed and the Tottenham Hale–Stratford link and the station at Lea Bridge ceased to be used by regular passenger trains. The line between Dalston and North Woolwich was electrified on the third-rail system and Broad Street services were diverted to North Woolwich using former Southern Region 2-EPB types built in the 1950s. The two-car trains soon proved too small and were replaced by three-car Class 313 electric multiple units. The new service was branded by British Rail as the North London Link, and some signs using this name still exist.
In December 2006, as with the Poplar branch, the line between Stratford and North Woolwich was permanently closed to make a way for a future DLR extension from to Stratford International. The section south of Canning Town was not used by the DLR, as it is largely duplicated by the DLR King George V branch. Instead, the section became part of the Elizabeth line's branch to, which opened in May 2022. The section south of Stratford had always been the 'Cinderella' end of the line, in that when there were operating problems it was common for trains to be turned short at Stratford.

Poor performance before the TfL takeover

Despite favourable performance figures, the North London line used to be regarded by frequent travellers as offering a poor and unreliable service with extremely congested trains which were often cancelled shortly before they were due to arrive. A 2006 London Assembly report described the current service as "shabby, unreliable, unsafe and overcrowded", proposing the transfer of the service to Transport for London as a solution to improve the quality of the service due to upgrade plans which coincided with the extension of the East London line.

TfL

The North London line, as part of Silverlink, along with the West London line, Gospel Oak to Barking line and the Watford DC line, was transferred to Transport for London in 2007 to form its new London Overground service. TfL began to remodel stations, integrate lines and, following the transfer and extension of the East London line, created an orbital rail service. TfL also brought in new trains and the lines, which previously appeared on tube maps following a public campaign, gained their own colour.
TfL closed the line in February 2010 between and for the installation of a new signalling system and the rebuilding or extension of platforms to allow four-car trains to run on the line; most NLL platforms had been reduced in usable length in the late 1960s when services were reduced to three-carriage trains only. The line reopened on 1 June 2010 with a reduced service and none on Sundays, and with the upgrade work completed, the full seven-day service resumed on 22 May 2011.

Former services

In addition to the primary – Richmond service, there were services that linked Broad Street with and on the Watford DC line. Most of these were routed via the line between and Camden Road, calling at although some travelled via and joined the DC line at. Prior to electrification in the 1960s, other services ran as far as Tring on the West Coast Main Line via Primrose Hill and Willesden Junction Main Line. By the time that Broad Street closed in 1986, the Watford services operated only in the rush hours; they were diverted to Liverpool Street by way of a new link in Hackney, known as the Graham Road Curve. Trains were frequently cancelled owing to rolling stock shortages; these circumstances had begun some years earlier with service reductions and scrapping of trains in the late 1960s, followed in later years by closure of depots at Croxley Green and Stonebridge Park preventing stabling of spare stock. Along with what eventually became a lack of trains timetabled to serve Liverpool Street to match the needs of rush-hour passengers, this inevitably led to falling patronage. British Rail applied to close the service in 1990, and the last trains ran two years later.
In 2000, Anglia Railways started a service between and, utilising parts of the North London line. The service was called London Crosslink and ran up to five times a day at roughly two-hourly intervals. The service called only at principal stations such as, and. On the North London line, the trains called only at,, Camden Road, and Willesden Junction. The service was withdrawn in 2002.
The AC electrification of the eastern part of the North London line uses the previously unelectrified northern pair of tracks, which were also partially singled at the same time. Between and Highbury & Islington, there is a line which links to the East Coast Main Line at. This used to carry passenger trains to and from various main line stations over part of the North London line to Broad Street Station; however, with the electrification of the Great Northern Electrics suburban lines in 1976, trains were diverted into and London King's Cross stations, so since then this link has only been used for freight trains. It too was singled concurrent with the AC electrification of the eastern part of the North London line.