Northern City Line

Northern City Line
LNER Alexandra Palace branch (conversion started but abandoned) Alexandra Palace Muswell Hill Northern line via Finchley Central Cranley Gardens Highgate depot Highgate Northern line via Kentish Town Crouch End Stroud Green East Coast Main Line to Edinburgh Finsbury Park Holloway Junction Drayton Park East Coast Main Line to London King's Cross Victoria line to Walthamstow Central North London line to Richmond Highbury & Islington North London and East London Lines via Canonbury Victoria line to Brixton Essex Road Old Street Thameslink Moorgate Lothbury

The Northern City Line is a branch railway and commuter line in England, which runs from Moorgate to Finsbury Park in London with services running beyond. It is part of the Great Northern Route services and operates as the south-eastern branch of the East Coast Main Line (ECML). It is underground from Moorgate to Drayton Park in Highbury from which point it runs in a cutting until joining the ECML south of Finsbury Park. Its stations span northern inner districts of Greater London southwards to the City of London, the UK's main financial centre. Since December 2015 the service timetable has been extended to run into the late evenings and at weekends,^[2] meeting a new franchise commitment for a minimum of 6 trains per hour until 23:59 on weekdays and 4 trains per hour at weekends.^[3]

The official name for this line is the Moorgate Line,^[4][5] however it is rarely referred to as this because of the confusion with another line with the same name which runs between Kentish Town and Farringdon (and, until recently, Moorgate surface level station) on the London Midland Region.^[6][7] The Northern City Line's name is derived from the fact that it was formerly part of London Transport's Underground network where it was described or managed as part of both the Metropolitan and Northern lines (sometimes as the "Highbury Branch"), although never connected to either. Built as an isolated route with a northern terminus at Finsbury Park, reconstruction connected it to the British Rail network in 1976 and began its modern service pattern. It is now owned by Network Rail and served by commuter trains operated by Great Northern from Moorgate to Welwyn Garden City, Hertford North and Letchworth Garden City.

In 2016, it was proposed that all London rail services should be transferred to Transport for London to create a London Suburban Metro, bringing the line under the jurisdiction of TfL.^[8]

History

The Great Northern & City Railway (GN&CR) was planned to allow electrified trains to run from the Great Northern Railway (GNR, now the East Coast Main Line) at Finsbury Park to the City of London at Moorgate. Despite being built using similar methods to the tube network then under construction, the tunnels were built large enough to take a main-line train, with an internal diameter of 16 feet (4.9 m), compared with those of the Central London Railway with a diameter less than 12 feet (3.7 m). However, the GNR eventually opposed the scheme and cancelled its electrification plans, and the line opened in 1904 with the northern terminus in tunnels underneath Finsbury Park GNR station. It was originally electrified using an unusual fourth-rail system with a conductor rail outside both running rails.^[9]

The GN&CR was bought in 1913 by the Metropolitan Railway, which operated what are today the Metropolitan and Hammersmith & City lines and the former East London line. They had plans to link it to the Circle and Waterloo & City lines, but these were never fulfilled.^[9] During this period, the line remained an isolated branch, without through services to any other part of the rail network. Carriages were brought to it through a connection into a freight yard near Drayton Park station, where a small depot was built to service trains.

The GN&CR generating station closed when the Metropolitan Railway took over, and became the studio of Gainsborough Pictures. After lying derelict for many years, it became a temporary venue for the Almeida Theatre. It has since been redeveloped as apartments.

After the Metropolitan Railway amalgamated with the other Underground railways as part of the formation of the London Passenger Transport Board in 1933, the line was renamed the Northern City Line and became branded as part of the Edgware-Morden Line, which was renamed to the Northern line in 1937. As part of London Transport's New Works Programme, the Northern Heights plan would have connected the Northern City Line at Finsbury Park to existing main-line suburban branches to Alexandra Palace, High Barnet and Edgware, which would be taken over by London Transport and electrified. The Highgate branch of the Edgware-Morden Line would connect to this network north of Highgate. Only parts of this plan were completed: when the Second World War started, the Highgate link and electrification of the Barnet branch were well under way and ultimately completed, but the Northern City connection to Highgate was first postponed and finally cancelled after the war.

The planned 1930s Northern Heights extensions, showing the diversion of the Northern City Line to Alexandra Palace, Bushey Heath and High Barnet. Sections marked in solid green were ultimately taken over. The line from Highgate to Finsbury Park already existed but was to be absorbed by London Transport; this never happened and it closed to passengers in 1954. After being used to transfer tube trains from Highgate depot to the Northern City line, it closed permanently in 1970.

After the war there were proposals to extend the Northern City Line north and south. The London Plan Working Party Report of 1949 proposed several new lines and suburban electrification schemes for London, lettered from A to M. The lower-priority routes J and K would have seen the Northern City Line extended to Woolwich (Route J) and Crystal Palace (Route K), retaining the "Northern Heights" extensions to Edgware and Alexandra Palace. The lines would have run in small-diameter tube tunnels south from Moorgate to Bank and London Bridge.^[10] The "K" branch would have run under Peckham to Peckham Rye, joining the old Crystal Palace (High Level) branch (which was still open in 1949) near Lordship Lane. Nothing came of these proposals, and the Edgware, Alexandra Palace and Crystal Palace (High Level) branches were all closed to passengers in 1954. As a result, the Northern City Line remained isolated from the rest of the network.

Services were cut back from Finsbury Park to Drayton Park in 1964 to make room for the Victoria line to use the low-level platforms at Finsbury Park. The former Piccadilly line platforms became the northbound Piccadilly and Victoria lines' platforms, and the former Northern City Line platforms the southbound equivalents. At the same time a change was made at Highbury & Islington, with the northbound Northern City line diverted to a new platform alongside the northbound Victoria line, and the southbound Victoria using the former northbound Northern City platform, both providing cross platform interchange. Passengers from Moorgate to Finsbury Park took the Northern City line to Highbury & Islington and then changed onto the Victoria.

In 1970 the line was renamed Northern line (Highbury Branch) and the following year an agreement was made to transfer it to British Rail and connect it (as intended by its original promoters) to the mainline via surface platforms at Finsbury Park as part of a wider plan to electrify ECML suburban services. By running commuter trains to Moorgate instead of King's Cross, congestion at King's Cross was relieved.

The last London Underground services ran in October 1975 and British Rail services commenced in August 1976, replacing services to Broad Street via the city branch of the North London Line. These British Rail services used the name "Great Northern Electrics". The track and tunnels are now owned by Network Rail. Services are provided by Great Northern to Welwyn Garden City and, via the Hertford Loop Line, to Hertford North (with some extending to Stevenage, Hitchin or Letchworth). The name "Northern City Line" has been revived to refer to the underground part of the route.

Infrastructure

From Finsbury Park to Drayton Park traction current is supplied at 25 kV AC via overhead line, controlled by York Electrical Control Room.^[11]

Network SouthEast branding at Essex Road station.

From Drayton Park to Moorgate traction current is supplied at 750 V DC via third rail. There are two electrical sections,^[11] separated by a gap at Poole Street:

• Queensland Road to Poole Street
• Poole Street to Finsbury Circus

Trains change from AC to DC traction supply, or vice versa whilst standing at Drayton Park station.^[11] The platform starter signal on the Up platform at Drayton Park is held at danger (red) as the train approaches. This ensures that all trains stop and drop the pantograph before entering the tunnel.

Signalling is controlled from Kings Cross power box.^[11] Between Drayton Park and Moorgate there is no Automatic warning system or Train Protection & Warning System equipment provided, due to the position of the auxiliary return rail^[11]. All signals are multiple aspect colour light signals fitted with train stop arms.^[11]

Moorgate, Old Street, Essex Road and Highbury & Islington stations retain Network SouthEast branding on the platforms, which has largely disappeared from the rest of the network.

Operating procedures

NCL Start of Procedures sign & Up platform starter signal at Drayton Park

Because mainline trains operate over the infrastructure inherited from London underground there are some practices on the NCL which differ from Railway Rulebook instructions, and these are contained in an additional publication.^[11] These include:

Passing signals at danger

If a train is standing at a signal at danger inside a tunnel and the driver is unable to contact the signaller, he is permitted to pass that signal under his own authority. As soon as he starts to move, the tripcock on the train will operate and stop the train so he must reset that before continuing. He must then proceed with caution, be prepared to stop short of any obstruction, and travel no faster than 3 mph (4.8 km/h).^[11] When he reaches the next signal he must stop and attempt to contact the signaller to inform him of what has taken place.

Platform starter signals (which let the train into a tunnel) can only be passed at danger with the signaller's authority.^[11]

Assisting a failed train

Unlike surface lines, the driver of a train which fails on the NCL is not required to leave the train to lay detonators and then wait for the assisting train. The driver remains with the train and the signaller will authorise the driver of the assisting train to proceed to the rear of the failed train at a maximum speed of 3 mph (4.8 km/h).^[11] To ensure that the rear of the failed train is always visible, all trains working over the NCL are required to display three red lights at their rear: two tail lamps plus the red portion of the destination roller blind.^[11]

On reaching the failed train, the assisting driver will stop short then clip his tunnel telephone onto the tunnel wires so that he can discuss with the driver of the failed train how they will carry out the assistance in order to get the trains moving again. Then the two trains are coupled together and the drivers can talk to each other over the usual cab-to-cab handsets before proceeding.

Rolling stock

Services are operated by dual-voltage Class 313 electric multiple units (EMUs), the only rolling stock certified for use on the line. In keeping with regulations for trains operating in single-bore tunnels where there is not enough room for side egress, they have emergency doors at the end of each unit. When operating on 750 V DC the two motor coaches collect traction current from their own shoe gear only; there is no traction bus linking them together as found on most Electric Multiple Units. All Class 313 units operating over the NCL have their Driving Motor B vehicle at the London end, and whilst on 750 V DC are electronically limited to 30 mph (48 km/h),^[12] which is the maximum line speed.^[4] All stations are long enough to accept six-car trains.^[13]

The Class 313 units are amongst the oldest EMUs still operating on the National Rail network. As a consequence, when it took over the Thameslink/Great Northern franchise, Govia Thameslink Railway announced that it would procure a total of 150 new Class 717 carriages to completely replace the Class 313 fleet operating services to Moorgate.^[14]

Accidents and incidents

Moorgate tube crash

The Moorgate tube crash, the most serious accident on the London Underground, occurred at Moorgate on 28 February 1975, when a Highbury Branch train ran through the terminus at speed and crashed into the dead end of the tunnel beyond. The cause of the accident, which killed 43 people, was never determined: a report found that there was insufficient evidence to say if the accident was due to a deliberate act or a medical condition.

Tunnel penetration incident

On 8 March 2013, pile driving operations from a building site in East Road, Hackney, 13 m (43 ft) above the tunnel, penetrated and obstructed the line between Old Street and Essex Road stations. A serious accident was averted by the actions of an observant train driver, and the line was restricted for several days for repairs. A subsequent investigation by the Rail Accident Investigation Branch was highly critical of the lack of infrastructure protection by Network Rail and carelessness on the part of the site investigation contractor, the piling contractor, and the local planning authority.^[15]

Passenger volume

This is the number of passengers using stations on the line from the year beginning April 2002 to the year beginning April 2013.

See also

• Northern Heights plan

References

Bibliography

External links

Wikimedia Commons has media related to Northern City Line.

• Underground Line Guide – Northern line – comprehensive history of the Northern line and its branches