These projects were mostly realised after the Second World War, when construction stopped and the unused tunnels were used as air-raid shelters and factories.

[8] The line was built following the streets above rather than running underneath buildings, because purchase of wayleave under private properties would have been expensive.

The line between Shepherd's Bush and Bank was formally opened on 30 June 1900, public services beginning on 30 July.

[12] It was initially operated by electric locomotives, with motor armatures built directly on the axles to eliminate noise-producing gearboxes, hauling carriages.

The line was extended westwards with a loop serving a single platform at Wood Lane for the 1908 Franco-British Exhibition.

[24] To the west new tracks were to be built parallel with the Great Western Railway's New North Main Line as far as Denham.

To the east, new tunnels would run to just beyond Stratford station, where the line would be extended over the London & North Eastern Railway suburban branch to Epping and Ongar in Essex, as well as a new underground line between Leytonstone and Newbury Park mostly under Eastern Avenue so as to serve the new suburbs of north Ilford and the Hainault Loop.

[citation needed] Most of the tunnels for the extensions to the east of London had been built by 1940, but work slowed due to the outbreak of the Second World War until eventually being suspended in June.

[28] The unused tunnels between Leytonstone and Newbury Park were equipped by the Plessey Company as an aircraft components factory, opening in March 1942 and employing 2,000 people.

[33] The powers to extend the line to Denham were never used due to post-war establishment of the Green Belt around London, which restricted development of land in the area.

[33] The eastern extension opened as far as Stratford in December 1946, with trains continuing without passengers to reverse in the cutting south of Leyton.

[33] South of Newbury Park, the west-facing junction with the main line closed in the same year to allow expansion of Ilford carriage depot.

[36] The extension transferred to London Underground management in 1949, when Epping began to be served by Central line trains.

[38] On 8 April 1953, 12 people were killed and 46 were injured as a result of a rear-end collision in a tunnel just to the east of Stratford station, caused by driver error after a signal failure.

[43] The entire Central line was shut between January and March 2003, after 32 passengers were injured when a train derailed at Chancery Lane due to a traction motor falling on to the track.

Loughton to Epping was opened on 24 April 1865 by the ECR's successor, the Great Eastern Railway (GER), along with the section to Ongar.

[3] When the railway opened in 1900, it was operated by electric locomotives hauling carriages with passengers boarding via lattice gates at each end.

After an investigation by the Board of Trade, by 1903 the carriages had been adapted to run as trailers and formed with new motor cars into electric multiple units.

[86] The single track section from Epping to Ongar was not electrified until 1957, prior to which the service was operated by an autotrain, carriages attached to a steam locomotive capable of being driven from either end, hired from British Railways, and an experimental AEC three-car lightweight diesel multiple unit operated part of the shuttle service Monday-Friday in June 1952.

[90] In accordance with this plan, the first 8-car trains of 1992 Stock entered service in 1993,[91][92] and while the necessary signalling works for ATO were in progress, One Person Operation (OPO) was phased in between 1993 and 1995.

[93] New motors, lighting, doors, and seats will be installed, and the trains will have passenger information displays, wheelchair areas and CCTV.

[94] However in November 2020 TfL reported that this had been delayed due to the COVID-19 pandemic, with expected completion by the end of 2025;[95] as of September 2024[update] only one refurbished train had re-entered service.

[93] In the mid 2010s, TfL began a process of ordering new rolling stock to replace trains on the Piccadilly, Central, Bakerloo and Waterloo & City lines.

[98] These trains would have an open gangway design, wider doorways, air conditioning and the ability to run automatically with a new signalling system.

During the Second World War, anti-aircraft guns were made at Ruislip Depot and the U.S. Army Transportation Corps assembled rolling stock at Hainault between 1943 and 1945.

[102] As part of the construction of the Westfield London shopping centre, the depot at White City was replaced underground, opening in 2007.

Services at peak times are less structured, and trains can run between any two terminus stations at irregular intervals (e.g. from Ealing Broadway to Epping).

[107] The Central crosses over the Metropolitan and Piccadilly lines' shared Uxbridge branch near West Ruislip depot, and a single track linking the two routes was laid in 1973.

[108] The Central line runs directly below Shoreditch High Street station and an interchange has been desired locally since it opened in 2010.

They argued this would reduce travel times to Epping and London, and help with efforts to add 19,000 new homes to the town and expand the population to 130,000.