Editing London Underground (section)

===London Passenger Transport Board era===
[[File:The Home Front in Britain during the Second World War HU44272.jpg|thumb|[[Aldwych tube station|Aldwych Underground station]] being used as a bomb shelter in 1940]]
In 1933, most of London's underground railways, tramway and bus services were merged to form the [[London Passenger Transport Board]], which used the [[London Transport (brand)|London Transport brand]].{{sfnp|Day|Reed|2010|p=110}} The [[Waterloo & City Railway]], which was by then in the ownership of the main line [[Southern Railway (UK)|Southern Railway]], remained with its existing owners.<ref name="culgwac">{{cite web |url=http://www.davros.org/rail/culg/waterloo.html |title=Waterloo & City Line |date=14 December 2007 |work=Clive's Underground Line Guides |publisher=Clive Feather |access-date=11 June 2015 |archive-date=12 April 2015 |archive-url=https://web.archive.org/web/20150412031513/http://www.davros.org/rail/culg/waterloo.html |url-status=live }}</ref> In the same year that the London Passenger Transport Board was formed, [[Harry Beck]]'s diagrammatic [[tube map]] first appeared.{{sfnp|Green|1987|p=46}}

In the following years, the outlying lines of the former Metropolitan Railway closed, the [[Brill Tramway]] in 1935, and the line from [[Quainton Road railway station|Quainton Road]] to [[Verney Junction railway station|Verney Junction]] in 1936.{{sfnp|Day|Reed|2010|p=118}} The 1935–40 [[New Works Programme]] included the extension of the Central and Northern lines and the Bakerloo line to take over the Metropolitan's Stanmore branch.{{sfnp|Day|Reed|2010|p=116}} The [[Second World War]] suspended these plans after the Bakerloo line had reached Stanmore and the Northern line [[High Barnet tube station|High Barnet]] and [[Mill Hill East tube station|Mill Hill East]] in 1941.{{sfnp|Day|Reed|2010|pp=131, 133–134}} Following bombing in 1940, passenger services over the [[West London line]] were suspended, leaving [[Olympia (London)|Olympia exhibition centre]] without a railway service until a District line shuttle from Earl's Court began after the war.{{sfnp|Horne|2006| p=73}} After work restarted on the Central line extensions in east and west London, these were completed in 1949.{{sfnp|Day|Reed|2010|pp=144–145}}

During the war many tube stations were used as air-raid shelters.{{sfnp|Day|Reed|2010|pp=135–136}} They were not always a guarantee of safety however; on 11 January 1941 during the [[London Blitz]], a bomb penetrated the booking hall of [[Bank Station]], the blast from which killed 111 people, many of whom were sleeping in passageways and on platforms.<ref>{{cite web |url=http://news.bbc.co.uk/local/london/hi/people_and_places/newsid_9357000/9357545.stm |title=Tribute to Bank Tube station bomb victims of 1941 |author=<!--Not stated--> |date=11 January 2011 |publisher=BBC London News |access-date=15 August 2021 |archive-date=15 August 2021 |archive-url=https://web.archive.org/web/20210815110331/http://news.bbc.co.uk/local/london/hi/people_and_places/newsid_9357000/9357545.stm |url-status=live }}</ref> On 3 March 1943, a test of the air-raid warning sirens, together with the firing of a new type of anti-aircraft rocket, resulted in a crush of people attempting to take shelter in [[Bethnal Green tube station|Bethnal Green Underground station]]. A total of 173 people, including 62 children, died, making this both the worst civilian disaster in Britain during the Second World War, and the largest loss of life in a single incident on the London Underground network.<ref>{{cite news |url=https://www.bbc.co.uk/news/uk-england-london-21645163 |title=Bethnal Green Tube disaster marked 70 years on |work=BBC News |date=3 March 2013 |access-date=11 June 2015 |archive-date=6 March 2013 |archive-url=https://web.archive.org/web/20130306014728/http://www.bbc.co.uk/news/uk-england-london-21645163 |url-status=live }}</ref>