Editing London Underground (section)

===Services using former and current main lines===
[[File:London Underground full map.svg|thumb|upright=1.35|A map of the entire system with accurate positions of stations but simplified presentation of lines]]
The Underground uses several railways and alignments that were built by main-line railway companies.
;Bakerloo line
:Between [[Queen's Park (London) station|Queen's Park]] and [[Harrow & Wealdstone station|Harrow & Wealdstone]] this runs over the [[Watford DC Line]] also used by [[London Overground]], alongside the [[London & North Western Railway]] (LNWR) main line that opened in 1837. The route was laid out by the LNWR in 1912–15 and is part of the [[Network Rail]] system.
;Central line
:The railway from just south of [[Leyton tube station|Leyton]] to just south of [[Loughton tube station|Loughton]] was built by [[Eastern Counties Railway]] in 1856 on the same alignment in use today.{{sfnp|Brown|2012}} The Underground also uses the line built in 1865 by the [[Great Eastern Railway]] (GER) between Loughton to [[Ongar tube station|Ongar]] via [[Epping tube station|Epping]]. The connection to the main line south of Leyton was closed in 1970 and removed in 1972. The line from Epping to Ongar was closed in 1994; most of the line is in use today by the heritage [[Epping Ongar Railway]].{{sfnp|Brown|2012}} The line between [[Newbury Park tube station|Newbury Park]] and Woodford junction (west of [[Roding Valley tube station|Roding Valley]]) via Hainault was built by the GER in 1903, the connections to the main line south of Newbury Park closing in 1947 (in the Ilford direction) and 1956 (in the Seven Kings direction).{{sfnp|Brown|2012}}
;Central line
:The line from just north of [[White City tube station|White City]] to [[Ealing Broadway tube station|Ealing Broadway]] was built in 1917 by the [[Great Western Railway]] (GWR) and passenger service introduced by the Underground in 1920. [[North Acton tube station|North Acton]] to [[West Ruislip tube station|West Ruislip]] was built by GWR on behalf of the Underground in 1947–8 alongside the pre-existing tracks from Old Oak Common junction towards {{rws|High Wycombe}} and beyond, which date from 1904.{{sfnp|Brown|2012}} {{As of|2013|5}}, the original Old Oak Common junction to {{rws|South Ruislip}} route has one main-line train a day to and from Paddington.<ref>{{NRtimes|May 13|115}}</ref>
;District line
:South of [[Kensington Olympia station|Kensington (Olympia)]] short sections of the 1862 [[West London Railway]] (WLR) and its 1863 West London Extension Railway (WLER) were used when District extended from Earl's Court in 1872. The District had its own bay platform at Olympia built in 1958 along with track on the bed of the 1862–3 WLR/WLER northbound. The southbound WLR/WLER became the new northbound main line at that time, and a new southbound main-line track was built through the site of former goods yard. The 1872 junction closed in 1958, and a further connection to the WLR just south of Olympia closed in 1992. The branch is now segregated.{{sfnp|Brown|2012}}
:The line between Campbell Road junction (now closed), near [[Bromley-by-Bow tube station|Bromley-by-Bow]], and [[Barking station|Barking]] was built by the [[London, Tilbury & Southend Railway]] (LTSR) in 1858. The slow tracks were built 1903–05, when District services were extended from [[Bow Road]] (though there were no District services east of [[East Ham tube station|East Ham]] from 1905 to 1932). The slow tracks were shared with LTSR stopping and goods trains until segregated by 1962, when main-line trains stopped serving intermediate stations.{{sfnp|Brown|2012}}
:The railway from Barking to [[Upminster tube station|Upminster]] was built by LTSR in 1885 and the District extended over the route in 1902. District withdrew between 1905 and 1932, when the route was quadrupled. Main-line trains ceased serving intermediate stations in 1962, and the District line today only uses the 1932 slow tracks.{{sfnp|Brown|2012}}
:The westbound track between east of [[Ravenscourt Park tube station|Ravenscourt Park]] and [[Turnham Green tube station|Turnham Green]] and Turnham Green to Richmond (also used by [[London Overground]]) follows the alignment of a railway built by the [[London & South Western Railway]] (LSWR) in 1869. The eastbound track between Turnham Green and east of Ravenscourt Park follows the alignment built in 1911; this was closed 1916 but was re-used when the Piccadilly line was extended in 1932.{{sfnp|Brown|2012}} The section between Turnham Green and Richmond still belongs to [[Network Rail]] now.<ref name="lu-iwa">Section 10 - Network Rail, London Underground - Individual Working Alone, [https://www.tectraining.co.uk/doc/LU-IWA-Information-Booklet-March-2015.pdf] {{Webarchive|url=https://web.archive.org/web/20230204191151/https://www.tectraining.co.uk/doc/LU-IWA-Information-Booklet-March-2015.pdf|date=4 February 2023}}</ref>
:The line between [[East Putney tube station|East Putney]] and [[Wimbledon station|Wimbledon]] was built by the LSWR in 1889. The last scheduled main-line service ran in 1941{{sfnp|Brown|2012}} but it still sees a few through Waterloo passenger services at the start and end of the daily timetable.<ref>Maund, Richard (2013). [http://www.psul4all.free-online.co.uk/2013.htm Passenger Train Services over Unusual Lines] {{webarchive|url=https://web.archive.org/web/20130701060420/http://www.psul4all.free-online.co.uk/2013.htm |date=1 July 2013 }}.</ref> The route is also used for scheduled ECS movements to/from Wimbledon Park depot and for Waterloo services diverted during disruptions and track closures elsewhere. This section is now owned by London Underground but the signalling is still operated by [[Network Rail]].<ref name="lu-iwa"/>
;Hammersmith & City
:Between [[Paddington tube station (Circle and Hammersmith & City lines)|Paddington]] and [[Westbourne Park tube station|Westbourne Park Underground station]], the line runs alongside the main line. The Great Western main line opened in 1838, serving a temporary terminus the other side of Bishop's Road. When the current Paddington station opened in 1854, the line passed to the south of the old station.{{sfnp|Brown|2012}} On opening in 1864, the Hammersmith & City Railway (then part of the Metropolitan Railway) ran via the main line to a junction at Westbourne Park, until 1867 when two tracks opened to the south of the main line, with a crossing near Westbourne Bridge, Paddington. The current two tracks to the north of the main line and the subway east of Westbourne Park opened in 1878.{{sfnp|Peacock|1970|p=67}} The Hammersmith & City route is now completely segregated from the main line.
;Jubilee line
:The rail route between [[Canning Town station|Canning Town]] and [[Stratford station|Stratford]] was built by the GER in 1846, with passenger services starting in 1847. The original alignment was quadrupled "in stages between 1860 and 1892" for freight services before the extra (western) tracks were lifted as traffic declined during the 20th century, and were re-laid for Jubilee line services that started in 1999. The current [[Docklands Light Railway]] (ex-North London line) uses the original eastern alignment and the Jubilee uses the western alignment.{{sfnp|Brown|2012}}
;Northern line
:The line from [[East Finchley tube station|East Finchley]] to [[Mill Hill East tube station|Mill Hill East]] was opened in 1867, and from [[Finchley Central tube station|Finchley Central]] to [[High Barnet tube station|High Barnet]] in 1872, both by the [[Great Northern Railway (Great Britain)|Great Northern Railway]].{{sfnp|Brown|2012}}
;Piccadilly line
:The westbound track between east of Ravenscourt Park and Turnham Green was built by LSWR in 1869, and originally used for eastbound main-line and District services. The eastbound track was built in 1911; it closed in 1916 but was re-used when the Piccadilly line was extended in 1932.{{sfnp|Brown|2012}}