Metropolitan line
The Metropolitan line, colloquially known as the Met, is a London Underground line between in the City of London and and in Buckinghamshire, with branches to in Hertfordshire and in Hillingdon. Printed in magenta on the tube map, the line is long and serves 34 stations. Between Aldgate and, the track lies mostly in shallow "cut and cover" tunnels, apart from short sections at and Farringdon stations. The rest of the line is above ground, with a loading gauge similar to those of main lines. Almost passenger journeys were made on the line in 2019.
This line is one of two Underground lines that cross the Greater London boundary and proceed outwards into the Home Counties, the other being the Central line. It is the only Underground line with an express service at peak times; the longer distance between stations means trains can achieve the system's highest speeds, up to, on some sections.
In 1863, the Metropolitan Railway was the world's first underground railway. It first ran between Paddington and, with wooden carriages and steam locomotives, subsequently extending north-westwards into the Middlesex countryside, where it stimulated the development of new suburbs. Harrow was reached in 1880, and ultimately the line continued as far as, in Buckinghamshire, more than from. From the end of the 19th century, the railway shared tracks with the Great Central Railway out of. The central London lines were electrified by 1907, but electric locomotives were exchanged for steam locomotives on trains heading north of Harrow. After the railway was absorbed by the London Passenger Transport Board in 1933, the line was cut back to. Steam trains ran until 1961, when the line was electrified to, and services were curtailed at, Amersham. The Hammersmith & City line was shown on the tube map as a part of the Metropolitan line until 1990, when it appeared as a separate line. The current S8 Stock trains entered service between 2010 and 2012, replacing the A Stock trains, which had served since 1961.
The section between Aldgate and Baker Street is shared with the Circle line; between Liverpool Street and Baker Street with the Hammersmith & City line; between and Uxbridge with the Piccadilly line; and between and Amersham with the London–Aylesbury line operated by Chiltern Railways. Baker Street is the southbound terminus for some trains not continuing to Aldgate. Most of the route has two tracks, except for the single-track Chesham branch and a four-track section between and, which allows fast and semi-fast services to overtake "all stations" trains. There are four tracks between Wembley Park and Finchley Road: only the outer ones are used by the Metropolitan line's non-stop trains; the inner pair was transferred to the Bakerloo line in 1939 with services calling at all stations.
History
Metropolitan Railway
The Metropolitan Railway, also known as the Met, was a passenger and goods railway that served London from 1863 to 1933, its main line heading north-west from the City to what were to become the Middlesex suburbs. Its first line connected the mainline railway termini at, and King's Cross to the City, built beneath the New Road using the cut-and-cover method between Paddington and King's Cross, and in tunnel and cuttings beside Farringdon Road from King's Cross to near Smithfield. The world's first underground railway, it opened on 10 January 1863 with gas-lit wooden carriages hauled by steam locomotives. The line operated at a frequency of three trains per hour, rising to four trains per hour during the peak periods. In the 1871 plans for an underground railway in Paris, it was called the Métropolitain.The railway was soon extended from both ends and northwards via a branch from Baker Street. It reached Hammersmith in 1864 and Richmond in 1877; it completed the Inner Circle in 1884, but the most important route became the line west and north-west into the Middlesex countryside, where it stimulated the development of new suburbs. Harrow was reached in 1880, and ultimately, as far as in Buckinghamshire, more than from Baker Street. From the end of the 19th century, the railway shared tracks with the Great Central Railway route out of.
Electric traction was introduced in 1905 with electric multiple units operating between Uxbridge, Harrow-on-the-Hill and Baker Street. To remove steam and smoke from the tunnels in central London, the railway purchased electric locomotives, exchanged for steam locomotives at Harrow from 1908. In 1910, a seventeen-minute silent film was made showing large portions of the journey from Baker Street to Aylesbury and Uxbridge, seen from the cab of a train.
Unlike other railways in the London area, the Met developed land for housing, thus benefitting from the increase in the value of its land caused by the building of the railway. After World War I it promoted its housing estates near the railway with the "Metro-land" brand.
To improve services, more powerful electric and steam locomotives were purchased in the 1920s. A short branch opened from Rickmansworth to Watford in 1925. After World War I, the Stanmore branch was built from Wembley Park.
London Transport
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 were withdrawn by 1936 though services returned to between 1943 and 1948.
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 branch to the Bakerloo line. In 1936, the line was extended east from to along the tracks of the District line. 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. In the 1950s, 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.
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 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. Aluminium 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; normally operated as eight cars, a four-car unit operated the Chesham shuttle. 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.
A separate identity
Although the East London line had been an isolated shuttle since 1939, it was shown on London Underground maps as part of the Metropolitan line until 1968. In 1970, it was shown with a thin white line in the middle and labelled the "East London section". By the 1985 map, it had become the "East London Line", remaining the same colour as the Metropolitan line with a white line in the middle, changed to orange by the 1990 map. In 1990, the Hammersmith & City line became a separate line from Hammersmith to Whitechapel, the Metropolitan line being from Aldgate to Baker Street and northwards to Amersham with branches to Chesham, Uxbridge and Watford.In 2003, the infrastructure was partly privatised in a public–private partnership managed by the Metronet consortium. Metronet entered administration in 2007 and Transport for London took over responsibilities.
On 12 December 2010, the service to Amersham was reduced from four trains per hour to two, and a direct service between Chesham and central London was introduced, replacing the 4-car Chesham to Chalfont & Latimer shuttle. The final passenger services operated by the A Stock ran on 26 September 2012, followed by a ticketed public railtour on 29 September.
Route
The Metropolitan line is long and serves 34 stations. It is electrified with a four-rail DC system: a central conductor rail is energised at –250 V and a rail outside the running rail at +500 V, giving a potential difference of 750 V, except for the section from Uxbridge to Finchley Road which is energised at –210 V and +420 V respectively to maintain compatibility with 1973 Stock and 1996 Stock that runs in those areas. The first from Aldgate are below ground, shared with the Circle and Hammersmith & City lines to Baker Street, where the line diverges, remaining in tunnel until Finchley Road. Metropolitan line trains essentially skip two stops between Baker Street and Finchley Road, with the Jubilee line serving the intermediate stations on an adjacent parallel line. The Jubilee line then joins the Metropolitan line in the same right-of-way at Finchley Road. Metropolitan line trains then run express from Finchley Road to Wembley Park, with the Jubilee line serving the intermediate stations. Metropolitan line platforms at and remain for emergency use. At Wembley Park the Jubilee line diverges to the Stanmore branch at a grade-separated junction. From just after Finchley Road, these four tracks run parallel with the Network Rail Chiltern Main Line from Marylebone.Between Wembley Park and Harrow-on-the-Hill, the Metropolitan is four-track, with fast and slow lines paired by direction, paralleling the two-track un-electrified London–Aylesbury line. The slow lines are between the fast lines, and the two intermediate stations have island platforms. Harrow-on-the-Hill has platforms on all six lines. The central slow lines diverge here at a grade-separated junction to become the Uxbridge branch. After West Harrow, at Rayners Lane the line is joined by the Piccadilly line, which shares the tracks to Uxbridge; a turnback siding allows some Piccadilly line services to terminate at Rayners Lane.
On the main line between Harrow-on-the-Hill and Moor Park, the line is four-track, paired by use. The western fast tracks are shared with Aylesbury line services from Marylebone; the eastern slow tracks have platforms at the intermediate stations.
North of Moor Park, the Watford branch diverges from the slow lines. This double-track branch has stations at Croxley and Watford. The Watford branch has a triangle junction with the main line, with a north-facing curve between and. This route, Watford North Curve, is used daily for a few services and empty stock movements.
From the Watford triangle to Amersham, the line has two tracks. At Chalfont & Latimer, the single-track Chesham branch diverges, running parallel to the main line for a distance. The Metropolitan line ends at Amersham, where there are turnback sidings just beyond the platforms. The route continues to Aylesbury with Chiltern Railways trains only.
The fast lines between Wembley Park and Harrow on the Hill are signalled with LUL signalling, but using four-aspect Network Rail signal heads. The upper two lights are a two-aspect stop signal displaying either a green or red aspect, the lower two lights a repeater signal for the next stop signal ahead showing a green or yellow aspect, or no aspect when the stop signal shows a red aspect. Thus they are effectively four-light three-aspect signals with green/red/green/yellow lights from the top, danger being a single red light, caution the top green light over a yellow light, and clear two green lights.
The Metropolitan line's suburban rail character opposed to other London Underground lines is also shown by the long distances between stops. Eight of the top 10 furthest apart stations on the Underground are on the Metropolitan line. The section between Chalfont & Latimer and Chesham is the longest at, whilst the Finchley Road to Wembley Park section is the second longest, and Rickmansworth to Chorleywood the fourth longest overall.