Editing London Underground (section)

====Sub-surface lines (District, Metropolitan, Hammersmith & City and Circle)====
{{main|Four Lines Modernisation}}

New S Stock trains have been introduced on the sub-surface (District, Metropolitan, Hammersmith & City and Circle) lines. These were all delivered by 2017. 191 trains have been introduced: 58 for the Metropolitan line and 133 for the Circle, District and Hammersmith & City lines. The track, electrical supply and signalling systems are also being upgraded in a programme to increase peak-hour capacity. The replacement of the signalling system and the introduction of Automatic Train Operation and Control is scheduled for 2019–22. A control room for the sub-surface network has been built in Hammersmith and an automatic train control (ATC) system is to replace ageing signalling equipment dating from between the mid-1920s and late 1980s, including the signal cabin at Edgware Road, the control room at Earl's Court, and the signalling centre at Baker Street. Bombardier won the contract in June 2011 but was released by agreement in December 2013, and London Underground has now issued another signalling contract, with Thales.<ref>{{cite web |title=Tube Improvements |url= https://tfl.gov.uk/campaign/tube-improvements/what-we-ve-done |date=n.d. |publisher=TfL |access-date=25 June 2015 |archive-url= https://web.archive.org/web/20150711143215/https://tfl.gov.uk/campaign/tube-improvements/what-we-ve-done |archive-date=11 July 2015 |url-status=dead }}</ref><ref>{{cite web |title= Third Time Lucky: A Look At The New Sub-Surface Signalling Plan |url= http://www.londonreconnections.com/2015/subsurface-railway-resignalling-saga-continues/ |date= 15 June 2015 |website= London Reconnections |access-date= 25 June 2015 |archive-date= 26 June 2015 |archive-url= https://web.archive.org/web/20150626103653/http://www.londonreconnections.com/2015/subsurface-railway-resignalling-saga-continues/ |url-status= live }}</ref><ref>{{cite web |title=SSR Signalling contract |url=https://tfl.gov.uk/cdn/static/cms/documents/fpc-20150617-item17-part-1-four-lines-modernisation.pdf |publisher=TfL |access-date=25 June 2015 |archive-date=26 June 2015 |archive-url=https://web.archive.org/web/20150626145855/https://tfl.gov.uk/cdn/static/cms/documents/fpc-20150617-item17-part-1-four-lines-modernisation.pdf |url-status=live }}</ref>