Great Eastern Main Line

The Great Eastern Main Line (GEML, sometimes referred to as the East Anglia Main Line) is a 212 Kilometre (133 mi) major railway line of the British railway system, which connects Liverpool Street in the City of London with destinations in east London and the East of England, including Chelmsford, Colchester, Ipswich, Norwich and several coastal resorts such as Clacton-on-Sea and Walton-on-the-Naze. It is primarily a commuter railway that also attracts business and leisure passengers, and a freight route.

History
The earliest section of the line operated between Devonshire Street railway station (Mile End) and Romford from 1839 and was built by the Eastern Counties Railway (ECR). The London terminus was then moved to Bishopsgate railway station (initially known as Shoreditch) on 1 July 1840 and the line was extended out to Brentwood in the same year. A further 51 miles of route was added to link London with Colchester by 1843. The original gauge for the line was 5 feet, but this was converted to Standard gauge (4′8½″) in 1844.

The section of line between Colchester and Ipswich was built by the Eastern Union Railway to Standard gauge and opened for passenger traffic on 15 June 1846 and the route to Norwich (Norwich Victoria railway station) opened in 1849.

Eastern Counties Railway and Eastern Union Railways and others were amalgamated to form the Great Eastern Railway in 1862.

The London terminus was again moved, this time to Liverpool Street on 2 February 1874.

The line was 'grouped' into the London and North Eastern Railway in 1923 and from 1948 formed part of the Eastern Region of British Railways.

In the 1930s a flyover was constructed just west of Ilford to switch the main and electric lines over, to enable main line trains to utilise Liverpool St's longer west side platforms without having to cross east side suburban traffic in the station throat. The new arrangement also facilitated cross-platform interchange with the Central line at Stratford, services commencing in 1946. Either side of Ilford Flyover, there are single-track connections between the slow and fast pairs of lines, with the westbound track extending to Manor Park railway station and just beyond. A short fifth platform face serves the track at Manor Park, but it sees no normal use. The eastbound track extends as far as Ilford, connecting with that station's fifth (bay) platform, which does see limited passenger operations. It was also envisaged that a flyover would be built at the country end of Gidea Park Carriage Sidings to switch Southend Victoria trains from the mains to the electrics, instead of at Shenfield London end junction as they do now.

Plans were drawn up in the 1930s to electrify the suburban lines from Liverpool Street to Shenfield at 1500 V DC and work was started on implementing this. However, the outbreak of the Second World War brought the project to a temporary halt and it was not until 1949 that the scheme was completed with electrification being extended to Chelmsford in 1956.

The British Railways 1955 Modernisation Plan called for overhead line systems in Great Britain to be standardised at 25 kV AC. However, due to low clearances under bridges the route was electrified at 6.25 kV AC. The section between Liverpool Street and Southend Victoria was completed in November 1960. Extensive testing showed that smaller electrical clearances could be tolerated for the 25 kV system than originally thought necessary. As a result it was now possible to increase the voltage without having to either raise bridges or lower the tracks along the route to obtain larger clearances. The route between Liverpool Street and Southend Victoria was converted to 25 kV AC between 1976 and 1980 Electrification was extended to Norwich by 1986.

In 1986 it became part of Network SouthEast. Between 5 January 1997 and 31 March 2004, suburban and medium distance services were operated by First Great Eastern, while fast mainline services were operated by Anglia Railways. All services are now operated by National Express East Anglia.

Liverpool Street IECC replaced signal boxes at Bethnal Green (closed 1997), Bow (closed 1996), Stratford (GE panel closed 1997), Ilford (closed 1996), Romford (closed 1998), Gidea Park (closed 1998), Shenfield (closed 1992) and Chelmsford (closed 1994). The system uses BR Mark 3 solid state interlockings, predominantly four-aspect signals and a combination of GEC-Alsthom HW2000 and Smiths clamp-lock point machines.

The first signalbox to be closed and transferred to Liverpool Street IECC was Shenfield, which had only opened in 1982. The last boxes to be transferred were at Romford and Gidea Park, and were the oldest of those being transferred, having been opened under the GER/LNER 1924 resignalling scheme.

Accidents

 * 1905 - Witham rail crash; 11 killed, 71 injured
 * 1915 - Ilford rail crash; 10 killed, 500 injured

Infrastructure
The line is owned and maintained by Network Rail. It is part of the Network Rail Strategic Route 7, is composed of SRS's 07.01, 07.02 and 07.03, and is classified as a primary line. The line has a loading gauge of W10 between Liverpool Street and Haughley junction and from there is W9 to Norwich. It has a line speed of between 80-105 mph.

The main line is electrified at 25 kV AC using overhead wires and comes under the control of Romford Electrical Control Room. The branches to Upminster, Southend Victoria, Southminster, Braintree, Clacton-on-Sea, Walton-on-the-Naze and Harwich Town are also electrified.

In between Romford and Chadwell Heath there is a small Network Rail OLE depot adjacent to the Jutsums Lane overbridge. In addition at the London end of the depot is Network Rail's Electrical Control Room that controls the supply and switching of the OHL system for the whole of the former Anglia Region.

Signalling is controlled by two main signalling centres, Liverpool Street IECC (opened in 1992) and Colchester PSB (opened in December 1983). Liverpool Street IECC controls signalling up to Marks Tey, where it fringes with Colchester PSB, which has control to Norwich. There are also several small signal boxes that control local infrastructure, such as Ingatestone box, which that has jurisdiction over several local level crossings.

Track layout
On leaving Liverpool Street, the route comprises two pairs of tracks, known as the Mains and the Electrics, with a further pair of tracks, the 'Suburbans', which carry the West Anglia Main Line alongside the GE to Bethnal Green Junction. It is possible for GE trains to use the 'Suburbans', but this is extremely rare because of the platform allocations at Liverpool Street.

From Bethnal Green the GE has four lines to Bow Junction, where there is a complex set of switches and crossings. A line from the LTS route joins the up electric and there are a further two lines, the up and down Temple Mills, giving access to the North London line and Temple Mills. The GE is six tracks up to the London end of Stratford and the junction to Temple Mills, and there are five lines through the station dropping to four at the country end.

A flyover just west of Ilford enables main line trains to utilise Liverpool St's longer west side platforms without having to cross east side suburban traffic in the station throat. This arrangement also facilitated cross-platform interchange with the Central line at Stratford. Either side of Ilford Flyover, there are single-track connections between the slow and fast pairs of lines, with the westbound track extending to Manor Park railway station and just beyond. A short fifth platform face serves the track at Manor Park, but it sees no normal use. The eastbound track extends as far as Ilford, connecting with that station's fifth (bay) platform, which does see limited passenger operations.

At Shenfield the line to Southend Victoria diverges and the main line route drops from four lines to two; this arrangement continues for the vast majority of the way to Norwich. There are several locations where the route has more than two lines, predominantly through stations such as Colchester and Ipswich, along with goods loops, such as at the London end of Ingatestone.

Stoke tunnel
The only railway tunnel on the Great Eastern Main Line is just to the south of the current Ipswich railway station. The 361 yd (330 m) long tunnel was built by Peter Bruff as part of the Ipswich to Ely Line. It was completed in 1846 and it is thought to be the earliest driven on a sharp continuous curve. During the excavation of the tunnel many important fossils were uncovered, including rhinoceros, lion, and, mammoth; the site was known as the 'Stoke Bone Beds'. The finds are considered important in understanding climate change during the Ice Age.

Rolling Stock
Electric locomotive-hauled inter-city trains on Norwich to London serivce. electric multiple units for inner and outer suburban passenger trains and diesel multiple units for non-electrified lines. Electric and diesel hauled freight services.


 * Class 315 - 320 seats across 4 cars. Maximum speed 75 mph (121 km/h)
 * Class 321 - 307 seats across 4 cars per trainset, 100 mph (161 km/h)
 * Class 360 (Desiro) - 4 cars per trainset, 100 mph (161 km/h)
 * Class 90 - InterCity express passenger trains, Maximum speed 110 mph, Running speed 100-105 mph
 * Class 170 - 3 cars per trainset, 100 mph (161 km/h) for London to Peterborough and Lowestoft services

2011 DLR extension
In February 2011, the DLR extension from to Stratford Regional and Stratford International is expected to be complete. It is using the former North London Line alignment that runs beside the Jubilee Line and will directly link Stratford Regional to its international counterpart, local stations to the south and existing DLR branches in the Royal Docks.

International services from Stratford
Eurostar trains may serve Stratford International station when the Docklands Light Railway (DLR) extension to the station is completed in autumn 2010 (see below). It may also be served by other cross channel operators currently looking at using the line (see High Speed 1 for details). This would provide, via a short walk, an interchange between the Great Eastern Main Line services and High Speed services to continental Europe.

Crossrail
In 2018, Crossrail will be completed which will take over the Shenfield metro service and take it via a tunnel through central London and link up with the Great Western Main Line as far as Maidenhead and Heathrow Airport. The Crossrail service will interchange with remaining Great Eastern Main Line services at (via new underground platforms),, Romford and Shenfield.

Proposed developments
The Greater Anglia RUS, published in December 2007 outlines a number of developments intended for the Great Eastern route. Other proposals have been announced separately.


 * 68 additional carriages to provide longer trains will be introduced between December 2009 and December 2011.
 * Extension of platform 10A at Stratford to increase peak flow and capacity during the period 2009-2014.
 * Additional path on the Colchester, Chelmsford and Southend routes during the period 2009-2014.
 * A turn-back facility at Chadwell Heath during the period 2009-2014.
 * A new station at Great Blakenham as part of the SnOasis development near Ipswich, which received its final go-ahead on 6 November 2008.
 * In 2017 the 'Shenfield Metro' service will be absorbed into Crossrail.

Services
Nearly all trains are operated by the National Express Group, using the National Express East Anglia brand name. The franchise began under the 'one' railway brand on 1 April 2004. As of May 2007 two c2c services operate during the late evening to Barking. This is a throwback to BR days when London Fenchurch Street closed early in the evening as a cost-saving exercise and all services operated from Liverpool Street.

Liverpool Street is the principal passenger destination, although Stratford, with connections to Canary Wharf, has grown in significance.

Main line
Outer suburban and inter-city services utilise the main lines between Liverpool Street and Shenfield. Branch lines diverge at Romford, Shenfield, Witham, Marks Tey, Colchester, Ipswich, Stowmarket and Norwich, with through services operating to some destinations. All services share the same tracks from Shenfield to Colchester.

Shenfield metro
A high-frequency service operates on the slow lines between Liverpool Street and Shenfield serving suburban stations. The off-peak service consists of six trains an hour. Some peak trains are scheduled to terminate at Ilford or Gidea Park. The line is mostly within Greater London, with two stations in the Brentwood borough of Essex.