Editing Metropolitan line (section)

=== London Transport ===
{{Main|Metropolitan line (1933–1988)}}
[[File:Neasden metropolitan line station geograph-2384536-by-Ben-Brooksbank.jpg|thumb|T Stock train passing Neasden Depot in 1959]]
On 1 July 1933, the Metropolitan was amalgamated with other Underground railways, tramway companies and bus operators to form the [[London Passenger Transport Board]], and a period of rationalisation followed.

While the Metropolitan was run as an outer suburban route with steam-hauled trains and goods services, the LPTB wished to focus on electrified trains and suburban traffic. Goods services were passed to the [[London and North Eastern Railway]], which also took over the role of providing steam locomotives for trains beyond the end of electrification at Rickmansworth. All services north-west of {{Stnlnk|Aylesbury}} were withdrawn by 1936{{sfn|Green|1987|pp=46–48}} though services returned to {{Stnlnk|Quainton Road}} between 1943 and 1948.{{sfn|Horne|2003|p=69}}

The 1930s was a period of rapid growth for the north-western suburbs of London, and LPTB developed ambitious plans to simplify the Metropolitan line and expand capacity. Several stations on the Uxbridge branch were rebuilt, replacing temporary wooden buildings with modernist designs and giving Uxbridge station a new site in the town centre. A major bottleneck in the line, the double-track tunnel from Baker Street to Finchley Road, was bypassed by boring two tube tunnels underneath the Metropolitan tunnels, transferring slow services and the [[Stanmore tube station|Stanmore]] branch to the [[Bakerloo line]].{{sfn|Green|1987|p=51}} (This route was transferred to the [[Jubilee line]] in 1979.){{sfn|Green|1987|p=63}} In 1936, the line was extended east from {{stl|London Underground|Whitechapel}} to {{stl|London Underground|Barking}} along the tracks of the District line.<ref name="Rose" /> London Transport inherited incompatible [[electric multiple units]] from the railway, including the 1927–33 multiple-unit compartment stock used on routes to Watford and Rickmansworth, and these were refurbished to form a uniform fleet and designated [[London Underground T Stock]].{{sfn|Bruce|1983|pp=72–74}} In the 1950s, [[London Underground F Stock|F Stock]] trains, with sliding doors under the control of the guard, were transferred from the District line; these mainly worked the semi-fast Harrow and Uxbridge services.{{sfn|Bruce|1983|pp=78–81}}

[[File:Rayner's Lane Station. - geograph.org.uk - 39714.jpg|thumb|right|A Stock vehicles at Rayners Lane in their original unpainted livery]]
A major rebuilding of the main line from Wembley Park to Amersham was planned in the 1930s but delayed by the war. The line from Wembley to Harrow was rebuilt immediately after the war and the project was completed from 1956 to 1962, on a more modest scale than originally planned. Until 1961, passenger trains continued to be attached to a steam locomotive at {{stl|London Underground|Rickmansworth}} to run to Aylesbury. The rebuilding electrified the line from Rickmansworth to Amersham, transferring all Aylesbury services to British Railways. A pair of fast lines was added from Harrow to north of Moor Park by 1962, allowing outer-suburban trains to run fast to Moor Park.{{sfn|Green|1987|p=55}}{{failed verification|date=September 2014}} Aluminium [[London Underground A60 and A62 Stock|A stock]], originally unpainted, replaced the T stock and locomotive-hauled trains. More A Stock trains were built in 1962–63 to replace the trains on the Uxbridge service, giving the main line a single train type for all services. A Stock was four-car units that could operate as four- or eight-car trains;{{sfn|Bruce|1983|p=110}} normally operated as eight cars, a four-car unit operated the Chesham shuttle.{{sfn|Bruce|1983|p=113}} [[Driver-only operation|One person operation]] of the trains was proposed in 1972, but due to conflict with the trade unions was not introduced on the line until 1986.<ref>{{cite book |last1=Croome |first1=Desmond F. |last2=Jackson |first2=Alan Arthur |title=Rails Through the Clay: A History of London's Tube Railways |year=1993 |publisher=Capital Transport |page=468 |isbn=978-1-85414-151-4}}</ref>