Northern City Line

The Northern City Line is a railway line from Moorgate to Finsbury Park in London, once part of the Great Northern Electrics line. It should not be confused with the City branch of the Northern line, nor with the North London Line. The line is underground from Moorgate to just south of Drayton Park, and runs in a cutting from there until meeting the East Coast Main Line south of Finsbury Park.

The line was formerly part of London Underground, and during its history has been part of both the Metropolitan and Northern lines, although it is connected to neither. It is now part of the National Rail network and is owned by Network Rail. The line is served by London commuter trains run by First Capital Connect on the lines London Moorgate - Welwyn Garden City and London Moorgate - Hertford North - (Letchworth Garden City).

Connections

 * Finsbury Park – Piccadilly and Victoria lines
 * Highbury & Islington – North London Line and Victoria line
 * Old Street – Northern line
 * Moorgate – Circle, Hammersmith & City, Metropolitan and Northern lines

Rolling stock
The line is electrified &mdash; 25 kV overhead as far south as Drayton Park and 750 V third rail from there to Moorgate. Services are operated by Class 313 electric multiple units (EMUs), the only units certified for use on the line. In keeping with the UK regulations for trains operating in single track tunnels, they have emergency doors at each end of the train, and are also designed so that when operating on 750 V DC the two motor coaches are electrically separate as far as the traction supply goes - unlike other contemporary units, there are no DC traction supply jumper cables between carriages. All stations are long enough to accept two, 3 car EMUs.

History
The line was originally named the Great Northern & City Railway, and was intended to allow mainline trains of the Great Northern Railway to run from Finsbury Park directly into the City of London at Moorgate. Accordingly, the tubes were made large enough to take a main-line train, unlike those of the other tube railways being built in London at the time. The internal diameter was 16 feet (4.9 m), compared with less than 12 feet (3.7 m) for the Central London Railway and smaller still for the original City & South London Railway tunnels. However, the Great Northern was lukewarm about the scheme, and the GN&CR had to settle for a northern terminus in tube underneath Finsbury Park station. The line opened in 1904. It was originally electrified with an unusual fourth-rail system featuring a conductor rail outside each running rail. This was altered to the standard LT arrangement at a later date.

The GN&CR was bought in 1913 by the Metropolitan Railway, which operated today's Metropolitan and Hammersmith & City lines and the ex-East London line. The Met made various plans to link it to some point on the Circle line or to the Waterloo & City line, but these never came to fruition.

After the Metropolitan was nationalised (along with the other underground lines) in 1933, the line was renamed the Northern City Line and became part of the Edgware-Morden Line (which became the Northern line in 1937) for operational purposes. As part of London Underground's "New Works" programme, plans were made to connect the Northern City Line to the surface at Finsbury Park, and then join suburban branches to Alexandra Palace, High Barnet and Edgware. The Highgate branch of the Edgware-Morden Line would be connected to this network north of Highgate. By the time the Second World War started, the Highgate link and electrification of the Barnet branch were well under way, but work on the Northern City link was postponed.

This "Northern Heights" plan was dropped after the war, and 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 platforms at Finsbury Park (Low level). The former Piccadilly line platforms are now the northbound Piccadilly/Victoria line platforms, and the former Northern City Line platforms are the southbound Piccadilly and Victoria line ones (of course, today trains once more go from Drayton Park to Finsbury Park, but to the high level station). In 1970 the line was renamed Northern line (Highbury Branch). The following year, an agreement was made to transfer the line to British Rail and connect it (as was intended by its original promoters) to the main line at Finsbury Park. 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 run into Broad Street via the North London Line. These BR services used the name "Great Northern Electrics". The track is now owned by Network Rail. Services, provided on the line by First Capital Connect, run to Welwyn Garden City or are Hertford Loop Line services to Hertford North (some extending to Stevenage or Letchworth). The name "Northern City Line" has been revived to refer to the subsurface part of the route.

The former Northern City Line terminus at Finsbury Park is now used by Southbound Victoria and Picadilly line London Underground services, allowing cross platform interchange between the two lines. Northbound Victoria line trains use the former Southbound Picadilly platform, again providing cross platform interchange with the Northbound Picadilly. This change was made in 1968 when the Victoria line opened, with Northern City trains terminating at Drayton Park.

As part of the opening of the Victoria line, a further change was made at Highbury and 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, also providing cross platform interchange.

The Moorgate tube crash, the most serious railway accident on the London Underground system, occurred at Moorgate station 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.

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

Green Party proposal
The Green Party has proposed that the Northern City Line be connected to the Waterloo & City line to create a new cross-London route. The core section of the route would be from Finsbury Park to Clapham Junction via Moorgate, Bank and Waterloo, with a new connection at Blackfriars. Through services could then run from Welwyn Garden City and Hertford North to destinations like Hounslow, Richmond, Shepperton, Kingston and Weybridge, thus enabling much better use of the capacity offered by this part of the network, particularly outside city commuting hours. However, the Waterloo & City was designed and built as a deep tube line; were this to be connected to the Northern City line this would mean either a reversion to using deep tube stock along the whole length (as when the NCL was part of the Northern line), or converting the Waterloo & City for main line sized rolling stock. The latter would be made more difficult still because of the tight curves, which would not suit conventional carriages. It would therefore probably mean boring completely new tunnels for much of the length.