Circle line (London Underground)

Circle

Colour on map	Yellow
Year opened	1884
Line type	Sub-Surface
Rolling stock	C Stock 6 cars per trainset
Stations served	36
Length	27 km (17 mi)
Depots	Hammersmith
Journeys made	68.485 million (2009)
Rail lines of Transport for London  London Underground lines   Bakerloo   Central   Circle   District   Hammersmith & City   Jubilee   Metropolitan   Northern   Piccadilly   Victoria   Waterloo & City Other lines   Docklands Light Railway   Tramlink   Overground

The Circle line, coloured yellow on the tube map, is the eighth-busiest line on the London Underground. It forms a loop line around the centre of London on the north side of the River Thames with, since 13 December 2009, an extension to Hammersmith on its north-western side.

History

Main articles: Metropolitan Railway and Metropolitan District Railway

The route now known as the Circle line was authorised when Acts of Parliament in 1853 and 1854 empowered the Metropolitan Railway (MR) and the Metropolitan District Railway (MDR) to construct the world's first underground railway in central London. From an initial section between Farringdon and Paddington, the route was gradually extended at each end. Financial difficulties in the construction of the section through the City of London and animosity between the two railway companies delayed completion of the full circuit until 6 October 1884, although it had been known as the Inner Circle since the 1870s.

Trains were originally hauled by steam engines, but electrification was started with an experimental section in 1900. A disagreement between the two companies over the method of electrification delayed the exercise, so that the first electric trains were introduced gradually over the 11 days to 24 September 1905.

The Circle took over many parts of the Metropolitan line, confining the latter to the north-west and limiting its interchanges with the District line. The Uxbridge branch of the Metropolitan last shared track with the District in 1933, when Piccadilly line services replaced the latter. In the east, the Barking service of the Metropolitan, also sharing track with the District, was designated part of the Hammersmith & City line in 1988, though in practice the Hammersmith & City service had already been run as a separate operation for many years.

Other circle routes

The Inner Circle and other circular routes

The success of the Inner Circle led to the operation of three other "circular" routes within the capital, over existing main-line routes and sections of the Inner Circle. Like the Inner Circle at the time they were established, none of them was actually a complete circle:

• Middle Circle: Aldgate to Mansion House via Addison Road (now Kensington Olympia)
• Outer Circle: Broad Street to Mansion House via Willesden Junction
• Super Outer Circle: St Pancras to Earl's Court via Cricklewood and South Acton.

These routes failed to attract the passenger numbers hoped for. The Super Outer Circle ran for only two years; the other two routes lasted longer, but were eventually cut back and finally ended (see the map for details). Other services on the lines continued. Today parts of the Outer Circle and Super Outer Circle routes are operated by London Overground trains on the North London Line. Plans to complete an outer rail loop have been relaunched under the name Orbirail.

7 July 2005 terrorist attack

Main article: 7 July 2005 London bombings

On 7 July 2005 two Circle line trains were bombed. The blasts occurred almost simultaneously at 08:50 BST, one between Liverpool Street and Aldgate and the other at Edgware Road.

Following the attacks, the whole of the Circle line was closed. While most other lines re-opened on 8 July, the Circle remained closed for several weeks, reopening a little less than a month after the attacks, on 4 August. Thirteen people were killed by the blasts on the Circle line trains. A third attack occurred on the Piccadilly line between King's Cross St Pancras and Russell Square.

Pre 13 December 2009

Prior to 13 December 2009, the Circle line formed a simple loop with 27 stations and 14.5 miles (23.3 km) of track, as shown below:

The Circle line before extension to Hammersmith

The route

The Circle line became known as such in 1949, when it was designated separately from its parent Metropolitan line and District lines, although it had been shown on Underground maps since 1947 (see history above). It is a "route" rather than a separate "line": it does not have any stations for its sole use and only two short sections of track over which it operates exclusively: the chords between High Street Kensington and Gloucester Road, and between Tower Hill and Aldgate.

A complete journey around the line took approximately 55 minutes, but timetabling constraints meant that each train had scheduled two-minute stops at High Street Kensington and Aldgate, extending the time required to about 59 minutes. This meant the service was operated with seven trains in each direction, providing an 8.5-minute service interval (but a shorter service interval in combination with other lines operating on the same tracks).

Since 13 December 2009, the name of the line has been misleading: it now has a "lassoo" shape, with 35 stations and 17 mi (27 km) of track.

In the north, east and west of central London, the loop part of the Circle line roughly follows the boundary of Travelcard Zone 1, but in the south a substantial portion of the zone is outside the Circle. With the extension on 13 December 2009, it ceased to be one of the two lines operated completely within Zone 1 (the other being the two-stop shuttle Waterloo & City line). Of the 35 stations, a substantial number have Circle line platforms wholly or almost wholly underground, while those at Edgware Road, Farringdon, Barbican, Aldgate, Sloane Square, South Kensington, High Street Kensington, Bayswater, Notting Hill Gate and Paddington are in cuttings or under train sheds. They are all below street level, albeit only by a few feet, whereas all the stations on the Hammersmith extension are above ground: most is an elevated railway, largely on brick arches.

Post 13 December 2009

Circle line since 13 December 2009

Extension

The Circle line extension extended the route from Edgware Road to Hammersmith.

The idea had been in discussion for some years: at one point diagrams were drawn up, for internal use only, bearing the provisional name "Hammersmith & Circle Line", the implication being that the two lines would be merged into one. This idea was abandoned in favour of the 'extension' to the Circle and retention of the Hammersmith & City route as a separate identity.

The extension was announced in March 2009 and introduced on 13 December 2009, when the Circle was extended from Edgware Road to Hammersmith, sharing tracks with the Hammersmith & City line (see station list above). Clockwise, the new service runs from Hammersmith to Edgware Road, and then makes a full loop of the circle to arrive at Edgware Road a second time, where trains terminate. Anticlockwise, trains leave Edgware Road, travel round the circle and pass through Edgware Road a second time, and continue to Hammersmith. This means it is no longer possible to travel between certain stations on the original Circle either side of Edgware Road (such as Baker Street and Bayswater) without either changing trains there or going the long way round. However, London Underground has said that giving the line fixed termini improves reliability. At the same time the day-time service interval on both the Circle and Hammersmith & City lines was increased from 8.5 to 10 minutes, between them providing a train every five minutes between Hammersmith and Liverpool Street. This increased the frequency on the Hammersmith branch by 70%, but slightly reduced it on the loop. Despite its new spiral shape, the Circle line has retained its name.

No new track was required as this was solely a change in route pattern, using existing lines. It now shares the tracks previously used only by the Hammersmith & City line, although movements were regularly made over this section to and from Hammersmith depot as the two lines already shared a common fleet of trains.

The extension was intended to reduce overcrowding on Hammersmith & City line trains between Hammersmith and Edgware Road by improving the frequency of trains on that section. It was also designed to bring about improved reliability, not only for the Circle line but also for the District, Hammersmith & City and Metropolitan lines, by slightly reducing the number of trains on the loop.^{[citation needed]}

Orbital routes

Orbital routes have an intrinsic problem of timetabling robustness. The trains are constantly in service and so there is little scope for "recovery time" if they are delayed. A single delay can have long-lasting knock-on effects and be much more disruptive than on a non-orbital railway. Recovery time can be created by timetabling longer stops at some stations, but this increases journey times. The current spiral route supposedly removed this problem because of the recovery time at both ends of the route.

Technical information

Trains

Main article: London Underground rolling stock

The 6-car C stock trains used on the Circle line are in the distinctive London Underground livery of red, white and blue. They were introduced 1969–70, with a further batch in 1978.

LUL says these 40-year-old trains, part of the same fleet that also operates the Hammersmith & City line, are "in an increasingly poor state", and they are to be replaced with new 7-car S stock air-conditioned trains from Bombardier Transportation, with delivery scheduled to begin in 2012 for completion by the end of 2014. In combination with new signalling (see below), this is expected to produce an eventual overall increase in the capacity of the route of up to 65%.

To accommodate these longer trains (117 metres (384 ft) long as opposed to 93 metres (305 ft) for C stock), station platforms are currently being lengthened.

Depots

The principal depot for the Circle line is at Hammersmith, but there are also sidings at Barking, Triangle Sidings (in Kensington) and Farringdon. Sidings at Edgware Road have been decommissioned.

Signalling

LUL intends to award a contract in 2012 to build a single signal control centre for the whole of the sub-surface network (Circle, District, Metropolitan, and Hammersmith & City lines). Some of the existing signalling dates from before the Second World War and it has become unreliable, with replacement components often unavailable. A new system will be installed with automatic train operation (ATO), which it is hoped will be fully working by 2018, increasing frequency in the central area from 27 to 32 trains per hour.

Stations

Circle line

Legend District line Hammersmith Goldhawk Road Hammersmith depot Shepherd's Bush Market Wood Lane Joint route section with Latimer Road Hammersmith & City line Ladbroke Grove Westbourne Park District line Royal Oak High Street Kensington Crossrail Gloucester Road Notting Hill Gate Bayswater South Kensington Paddington Praed Street Junction Sloane Square Edgware Road Victoria Metropolitan line Baker Street St James's Park Great Portland Street Westminster Euston Square (Euston) Embankment Thameslink (Charing Cross) King's Cross St. Pancras Temple Farringdon Blackfriars City Thameslink (Tube station closed until 2011) Mansion House Barbican Cannon Street Monument Tower Hill Moorgate (Fenchurch Street) Liverpool Street Aldgate Crossrail District line Hammersmith & City line

Station	Image	Opened	Additional information
Hammersmith		1 December 1868	Hammersmith & City. This is the terminus for trains travelling anticlockwise.
Goldhawk Road		13 June 1864
Shepherd's Bush Market		13 June 1864
Wood Lane		12 October 2008
Latimer Road		16 December 1868
Ladbroke Grove		13 June 1864
Westbourne Park		30 October 1871
Royal Oak		30 October 1871
Paddington		10 January 1863	Bakerloo, District, Hammersmith & City, Great Western Main Line
Edgware Road		1 October 1863	District, Hammersmith & City, Bakerloo (150 m (490 ft)). This is the terminus for trains travelling clockwise.
Baker Street		10 January 1863	Bakerloo, Jubilee, Metropolitan
Great Portland Street		10 January 1863
Euston Square		10 January 1863	Euston and West Coast Main Line
King's Cross St Pancras		10 January 1863	Northern, Piccadilly, Victoria. Main line stations: St Pancras for Eurostar, Southeastern Highspeed (High Speed 1), East Midlands Trains (Midland Main Line) and First Capital Connect (Thameslink) King's Cross for East Coast, First Hull Trains, Grand Central and First Capital Connect (East Coast Main Line/Fen Line)
Farringdon		10 January 1863	First Capital Connect (Thameslink)
Barbican		23 December 1865
Moorgate		23 December 1865	Northern, First Capital Connect (Northern City Line)
Liverpool Street		12 July 1874	Central, National Express East Anglia, c2c
Aldgate		18 November 1876	Metropolitan
Tower Hill		25 September 1882	District
Monument		6 October 1884	Central, Northern, Waterloo & City, DLR (all via escalator connection to Bank station)
Cannon Street		6 October 1884	Southeastern
Mansion House		3 July 1871
Blackfriars (closed until February 2012)		30 May 1870	First Capital Connect / Southeastern (Thameslink)
Temple		30 May 1870
Embankment		30 May 1870	Bakerloo, Northern
Westminster		24 December 1868	Jubilee
St James's Park		24 December 1868
Victoria		24 December 1868	Victoria, Southeastern, Southern
Sloane Square		24 December 1868
South Kensington		24 December 1868	Piccadilly
Gloucester Road		1 October 1868	Piccadilly
High Street Kensington		1 October 1868	District
Notting Hill Gate		1 October 1868	Central
Bayswater		1 October 1868
Paddington		1 October 1868	Bakerloo, District, Hammersmith & City, Great Western Main Line

The line then continues to Edgware Road where trains terminate, then reverse to traverse the loop in an anticlockwise direction to Hammersmith.

Circle line parties

The Circle line suspended due to a May 2008 party

Circle-line parties have gained in popularity in the 21st century, similar to subway parties in the United States. These involve large groups of people boarding a train and holding an impromptu party in the carriages, often dressing in costume.

A high-profile Circle-line party took place on 31 May 2008 to celebrate the last night of legal alcohol drinking on public transport in London. Thousands of people attended and 17 were arrested by police due to disorderly behaviour, eventually causing the entire line to be suspended for the rest of the night.

Maps

• ^map 1 Hammersmith – 51°29′39″N 000°13′30″W
• ^map 2 Goldhawk Road – 51°30′07″N 000°13′37″W
• ^map 3 Shepherd's Bush Market – 51°30′21″N 000°13′35″W
• ^map 4 Wood Lane – 51°30′35″N 000°13′27″W
• ^map 5 Latimer Road – 51°30′50″N 000°13′02″W
• ^map 6 Ladbroke Grove – 51°31′02″N 000°12′38″W
• ^map 7 Westbourne Park – 51°31′16″N 000°12′04″W
• ^map 8 Royal Oak – 51°31′09″N 000°11′17″W
• ^map 9 Paddington – 51°31′02″N 000°10′39″W
• ^map 10 Edgware Road – 51°31′12″N 000°10′04″W
• ^map 11 Baker Street – 51°31′19″N 000°09′25″W
• ^map 12 Great Portland Street – 51°31′26″N 000°08′38″W
• ^map 13 Euston Square – 51°31′33″N 000°08′09″W
• ^map 14 King's Cross St Pancras – 51°31′49″N 000°07′27″W
• ^map 15 Farringdon – 51°31′12″N 000°06′19″W
• ^map 16 Barbican – 51°31′13″N 000°05′52″W
• ^map 17 Moorgate – 51°31′07″N 000°05′19″W
• ^map 18 Liverpool Street – 51°31′07″N 000°04′53″W

• ^map 19 Aldgate – 51°30′50″N 000°04′34″W
• ^map 20 Tower Hill – 51°30′36″N 000°04′34″W
• ^map 21 Monument – 51°30′47″N 000°05′17″W
• ^map 22 Cannon Street – 51°30′37″N 000°05′27″W
• ^map 23 Mansion House – 51°30′44″N 000°05′39″W
• ^map 24 Blackfriars – 51°30′42″N 000°06′11″W
• ^map 25 Temple – 51°30′40″N 000°06′52″W
• ^map 26 Embankment – 51°30′25″N 000°07′19″W
• ^map 27 Westminster – 51°30′04″N 000°07′30″W
• ^map 28 St James's Park – 51°29′58″N 000°08′04″W
• ^map 29 Victoria – 51°29′48″N 000°08′41″W
• ^map 30 Sloane Square – 51°29′33″N 000°09′24″W
• ^map 31 South Kensington – 51°29′39″N 000°10′26″W
• ^map 32 Gloucester Road – 51°29′41″N 000°10′59″W
• ^map 33 High Street Kensington – 51°30′03″N 000°11′33″W
• ^map 34 Notting Hill Gate – 51°30′32″N 000°11′49″W
• ^map 35 Bayswater – 51°30′43″N 000°11′17″W
• ^map 36 Hammersmith Depot – 51°29′52″N 000°13′31″W

See also

• Cromwell Curve

External links

• "Circle line facts". Transport for London. http://www.tfl.gov.uk/tfl/corporate/modesoftransport/tube/linefacts/?line=circle. Retrieved 11 July 2008. 
• Subsurface network (SSL) upgrade information at alwaystouchout.com
• "Proposals for the Upgrade of the Sub-surface Lines". Tube Prune. 9 December 2003. http://www.trainweb.org/tubeprune/SSL%20PPP%20Upgrade.htm. Retrieved 11 July 2008.