A lot has been written over the years about the history of the Northern Heights plan. This is my own modest account.
By the time Harry Beck’s first diagrammatical map of the London Underground came out in 1933 much of today’s Northern Line had already been completed. The line had been created by amalgamating two different tube railways (what we know today as the Bank and Charing Cross branches) with junctions at Camden in the north and Kennington in the south. By 1926 it had already reached its current southern terminus: Morden and one of its northern ones: Edgware.
In fact, the only real differences with today were the fact that its north-eastern branch from Camden Town only went as far as Archway (then known as Highgate), and its name. Although the line was using its now-familiar black colour on the 1933 map, it was shown as the “Edgware, Highgate & Morden Line”. It also sometimes masqueraded as the Morden-Edgware Line”.
The “Northern” name was only adopted in 1937 and it was intended as a reference to the substantial new network of extensions to be completed as part of the 1935-40 new works programme.
The overall name given to these plans was “Northern Heights” which was a reference to the area of high ground in the north of London through which the lines passed.
The project involved linking the “Edgware, Highgate & Morden Line” with another tube line, some LNER steam-worked lines and then extending it for a few more miles further north using the route of a previously planned but unbuilt railway.
The Big Tube
The other tube line in the plan was also shown on the 1933 map; and was by then known as the “Great Northern & City Section” of the Metropolitan Line. It was coloured in the Metropolitan line’s purple but was hollowed out to keep a bit of a distinction. It stretched from Moorgate to Finsbury Park with just 4 intermediate stations.
The line had been built back in 1904 by the Great Northern & City Railway (GN&CR) and its original ambition had been to link to the main line operated by the Great Northern Railway (GNR) at Finsbury Park and provide stations along it with a better link to Moorgate in the city.
It was a tube railway but it was built to allow mainline size stock to use it in line with its original goal. Unfortunately a dispute meant that the GNR denied it connection with the surface lines at Finsbury park and forced it to terminate underneath the station. It passed into the ownership of the Metropolitan Railway in 1913 and then to the London Passenger Transport Board (LPTB) in 1933.
The Steam Lines
The LNER steam-worked lines that were to be incorporated into the new scheme led west from Finsbury Park and had their own interesting history.
The Edgware, Hampstead, and London Railway (EH&LR) planned a line from Finsbury Park to Edgware in the early 1860s but was purchased by the Great Northern Railway (GNR) before it opened in 1867. The line ran from Finsbury Park for almost 9 miles to Edgware passing through what was then rural Middlesex via Crouch End, Highgate, Finchley, and Mill Hill. The line was built on a double track formation but initially only a single line was laid.
It was doubled as far as what is now Finchley Central when a branch from there to High Barnet was opened in 1872. This branch benefited from local housing developments and quickly became the more popular route. The remaining part of the original line from Finchley to Edgware remained single track and was mostly operated by a shuttle service. Another branch from Highgate to Alexandra Palace was opened in 1873. Initially it was run by a separate company but it was eventually taken over by the GNR in 1911.
In general, these lines did well and by the early 1900s they were even experiencing overcrowding. There was also reasonable freight revenue from the transportation of coal, milk and building materials. The GNR was absorbed by the London North Eastern Railway (LNER) in 1923.
At the start of the 1930s, Finsbury Park was receiving around 50 trains daily from High Barnet, 40 from Alexandra Palace and a few through services from Edgware. From Finsbury Park these trains continued to either King’s Cross, Moorgate (via the Metropolitan line connection) or Broad Street.
The Extension
The Watford and Edgware Railway (W&ER) was established in the 1860s and had plans to build a railway north to Watford from the GNR line at Edgware. In the end, it was never able to attract sufficient funds for the project but the right of way that it had obtained eventually passed through the ownership of several other railway companies to the Underground Group (UERL) in 1922.
The UERL’s own line had just reached its own separate station at Edgware in 1924 and it now planned to build the extension from there instead. The idea stalled though, and no work had been started by the time the UERL was absorbed into the LPTB in 1933.
The Northern Heights Plan
The London Passenger Transport Board (LPTB) was formed in 1933 as a new public body to control transport in the capital. Under the strong leadership of its CEO Frank Pick, it soon embarked on ambitious plans to integrate and improve the transport system of the metropolis.
The New Works plan of 1935-40 included projects for several tube lines and among the most ambitious were plans for what would soon become known as the Northern Line. The main idea revolved around three sets of connections to link existing railways together.
The first connection would involve the old GN&CR line being linked to new platforms in front of the main line station at Finsbury Park. This line would then feed into directly into the LNER lines to Alexandra Palace, High Barnet, and Edgware, all of which would be electrified and transferred to the LPTB. The original tunnel terminus under the station at Finsbury Park would also be kept for extra traffic.
The second connection would involve a link from the existing LPTB Highgate (now Archway) station to a new tube station directly below the LNER Highgate station. The line would then continue to the surface and emerge into the open air just east of East Finchley station, thus connecting the existing tube with both the High Barnet and Edgware lines.
Finally at Edgware, the LNER station would be closed, and a new connection made into the LPTB station, from where the line would be extended a few miles northwards to terminate at Bushey Heath. There would be three new stations and a large new depot would be built at Aldenham (between the last two stations) to service all the new tube trains needed for the enlarged line.
Service Plan
All the work was scheduled for completion by 1941 and the initial proposed service pattern appears on Wikipedia. Although it would probably still have been amended before introduction of the services, it is useful as a guide to what might have been.
It suggests that there would have be 28 tube trains an hour in the peak from Moorgate (shown on the map below in blue) with 14 terminating in the original tunnel terminus at Finsbury Park and 14 continuing to the mainline station and onto the LNER line to Highgate. 7 would have served Alexandra Palace and 7 would have continued to East Finchley to terminate either at Finchley Central or continue to High Barnet.
On the tube line from Camden Town via Archway there would have been 21 trains an hour (shown above in red), 14 having come via the Charing Cross branch and 7 from the Bank branch. These 21 trains would emerge alongside the trains from Moorgate at East Finchley and continue to Finchley Central. 7 would have continued along the High Barnet branch and 7 would have continued via Edgware to the new terminus at Bushey Heath.
The Edgware branch would have retained its existing pattern of services (not shown) and it was not envisaged that any trains would run to Bushey Heath from it.
In addition to all the increased frequencies, it was planned that the line would be supplied with brand new 1938 tube stock (the first to have all equipment beneath the floor or under the seats) which would increase passenger carrying capacity on each train.
Construction Begins
In preparation for the completion of the scheme, the whole line (including the GN&CR line) was renamed Northern Line in 1937 and the planned routes began to appear as dotted lines on existing tube maps. Progress was relatively swift, and the plan to have the whole system opened by 1941 looked achievable. In July 1939 services began on the new tube line linking Archway (formerly Highgate) with East Finchley via the new station at Highgate (opened later in 1941).
Inevitably, work was soon interrupted by the Second World War. Although, some of it did continue, and tube trains were able to replace LNER steam trains on the High Barnet Branch in April 1940 and reached Mill Hill East in May 1941, effectively completing what is today’s Northern Line.
Elsewhere though, everything stopped. The conversion of the rest of the Edgware line and the Bushey Heath extension was postponed until after the war. Electrification of the tracks between Finsbury Park and Alexandra Palace was also put on hold and LNER steam trains continued to operate the line. Construction of the new platforms at Finsbury Park also ground to a halt.
Cancellation
After the war, work never started again as London Transport’s sparce funds were used for reconstruction of war damage and the completion of the western and eastern extensions of the Central line which were given higher priority.
In 1947 green belt legislation was introduced to limit the outward expansion of London into the surrounding countryside. This prevented the planned residential developments around Bushey Heath and thus the need for the extra stations was removed.
The project was postponed a few times and then cancelled in stages between 1950 and 1954.
Post War
The intended track bed between Edgware and Brockley Hill was eventually built on, further north the route was left as open countryside. The Aldenham bus works was built on the site the intended depot.
The line between Edgware and Mill Hill East was used for freight by BR until 1964 and then lifted with the track bed abandoned to nature or covered by housing developments.
The steam trains on the LNER branch which had been cut back just to serve the Alexandra Palace branch suffered from declining passenger numbers. The line was closed to passengers between Highgate and Alexandra Palace in 1954 and completely in 1956.
Freight traffic continued on the old LNER line between East Finchley and Finsbury Park until 1964, and then until 1970 it was used for occasional tube stock transfers using battery locomotives. The track was lifted in 1972 and eventually became part of the Parkland Walk.
Work to connect the old GN&CR line was abandoned and the line, now the Highbury branch of the Northern line, continued to be a shuttle from its Finsbury Park tunnel terminus to Moorgate. The part-completed platforms in front of Finsbury Park station were only finally demolished in the 1970s.
In 1964 the old GN&CR line was cut back to Drayton Park and its Finsbury Park tube platforms were used in connection with the construction of the new Victoria Line. When it opened in 1969, the new line provided a cross-platform interchange at Highbury and Islington.
Then finally in 1976 the line achieved the purpose for which it had been intended back in 1904: it was transferred to British Rail, a connection from Drayton Park to the main Finsbury Park station was finally made and trains began running to Hertford North and Welwyn Garden City. This pattern has continued until today.
Southern Heights
And finally….
After 70 years the Northern line is now being extended !
The new tube tunnel from Kennington to Battersea via Nine Elms is due to open soon.
This will add another two southern stations to a line that reaches the southernmost point on the whole underground system and already has the most stations south of the Thames of any line !
Links to Walks
Walk 1 – Moorgate to Finsbury Park (3.6 miles)
Walk 2 – Finsbury Park to Alexandra Palace (4.4 miles)
Walk 3 – Archway to High Barnet (8.3 miles)
Walk 4 – Finchley Central to Edgware (4.5 miles)
Walk 5 – Edgware to Elstree & Borehamwood (6.6 miles)
Sources / Further Reading
The following books are in my personal collection….
On the Northern Heights in particular
- Beard, Tony (2002). By Tube Beyond Edgware. Capital Transport. ISBN 978-1-85414-246-7.
On London Underground station architecture
- Menear, Laurence (1983) London’s Underground Stations. A Social and Architectural Study. ISBN 0 85936 124 1
On London’s transport history in general –
- Tailor, Shelia (2001) The Moving Metropolis. A History of London’s Transport since 1800. ISBN 1 85669326 0
- Green, Oliver (2013) Frank Pick’s London. Art, design and the modern city. ISBN 978 1 85177 757 0
- Barman, Christian (1979) The man who built London Transport. ISBN 0 7153 7753 1
- Wolmar, Christian (2004) The Subterranean Railway. How the London Underground was built and how it changed the city forever. ISBN 1 84354 023 1
- Martin, Andrew (2012) Underground Overground. A passenger’s history of the tube. ISBN 978 1 84668 477 7
Website Links (valid in 2021)
Clive’s Underground Line Guides contains a lot of fascinating information on London Underground’s history.
Disused Stations is an amazing website and an excellent way of finding out the history of many closed stations in the UK. I have provided links in the text to the site’s page on all the disused stations I have visited.
Modernism in Metroland provides a useful guide to Art Deco and Modernist buildings in London’s suburbs and includes images of some of the unbuilt Northern Heights stations.
YouTube Links (valid in 2021)
On the Northern Heights specifically
Cab View
Cab view from High Barnet – Ben’s Underground Trains – The first 15 minutes show the stations of the High Barnet branch and the entry into the 1939 tube tunnel link to Archway after East Finchley.
On Alexandra Palace
Trains To Beyond 
