The Northern Heights Plan

The Grand Design

The Northern Heights plan was born of a particular moment in London's transport history — a moment when the new London Passenger Transport Board, created in 1933 under the visionary leadership of Frank Pick and the administrative genius of Lord Ashfield, was drawing together the fragmented railway and bus services of the capital into a unified system. The LPTB inherited not only the Underground railways and the bus and tram networks but also a number of surface railway lines that served the outer suburbs, and it was the fate of two of these lines — the Great Northern Railway branches to Edgware and to Alexandra Palace — that the Northern Heights plan was designed to determine.

The two branches ran northward from Finsbury Park through Stroud Green, Crouch End, and Highgate before diverging — one heading west through Muswell Hill to Alexandra Palace, the other continuing north through East Finchley to Edgware. Both lines were operated by the London and North Eastern Railway, which had inherited them from the Great Northern. They were steam-worked, lightly used, and financially struggling. The LPTB proposed to take over both branches, electrify them, and incorporate them into the Northern Line, creating a continuous tube service from Morden in the south to Edgware and Alexandra Palace in the north. It was an ambitious plan that would transform the transport geography of north London and open up large areas of suburban land for development.

The plan was formally announced in 1935 as part of the LPTB's New Works Programme, a comprehensive investment scheme that also included the extension of the Central Line to the east and west, the electrification of the Metropolitan Line's outer branches, and various station improvements and capacity enhancements across the network. The Northern Heights element of the programme was estimated to cost several million pounds — a vast sum in the 1930s — and was expected to take several years to complete. Work began almost immediately, with surveys, land acquisitions, and preliminary engineering taking place throughout 1936 and 1937.

The Highgate Connection

The key engineering challenge of the Northern Heights plan was the connection between the existing Northern Line tube tunnel at Archway and the surface railway at Highgate. The Northern Line ran in deep-level tube tunnels from its southern terminus to Archway, where it emerged into a sub-surface cutting before continuing to East Finchley. The surface railway, by contrast, ran at a higher level on the opposite side of the Highgate ridge. Connecting the two required a new section of tunnel that would climb from the deep-level tube alignment to the surface railway level — a gradient that pushed the limits of what was acceptable for electric traction.

The solution adopted by the LPTB's engineers was a new pair of tunnels that would diverge from the existing Northern Line alignment north of Archway station and climb steeply through the clay of the Highgate ridge to emerge at a new underground station beneath the existing Highgate station. This new station — Highgate (Underground) — would have platforms in the deep-level tunnels for the tube trains and would connect to the surface-level platforms above, where the LNER trains currently ran. Passengers would be able to transfer between the tube and the surface services, and the combined station would serve as a hub for the entire Northern Heights network.

The construction of these connecting tunnels was the most substantial piece of engineering in the entire Northern Heights programme. The tunnels were driven through London Clay using shield tunnelling methods — the same techniques that had been used to build the deep-level tube network since the 1890s — and they were lined with cast-iron segments bolted together to form watertight rings. The gradient of the tunnels, which climbed at a rate of about 1 in 50, was steep but manageable for the electric trains that would operate the service. The work progressed steadily through 1938 and 1939, and by the time war broke out in September 1939, the connecting tunnels were substantially complete.

Construction Begins and War Intervenes

Above ground, the Northern Heights programme was transforming the stations along the two branches. At East Finchley, a striking new station building designed by Charles Holden — the architect responsible for many of the finest stations on the Piccadilly and Northern lines — was nearing completion, its clean modernist lines and distinctive archer statue a dramatic contrast to the Victorian buildings it replaced. At Highgate, work had begun on the new underground station beneath the existing surface platforms. New platforms were being built at several intermediate stations, and the track was being relaid to accommodate the heavier electric trains.

The Alexandra Palace branch received less attention than the Edgware branch, partly because the LPTB considered it the less commercially promising of the two routes and partly because the engineering challenges of the branch — which included steep gradients and tight curves through the hilly terrain of Muswell Hill — were more formidable. New platforms were built at Cranley Gardens and Highgate, but the electrification work on this branch had barely begun when the war intervened. The stations at Stroud Green, Crouch End, and Muswell Hill were largely untouched by the modernisation programme.

The outbreak of war in September 1939 did not immediately halt the Northern Heights programme. Work continued through the autumn and winter of 1939-40, and the connecting tunnels between Archway and Highgate were completed in early 1940. The Edgware branch was electrified as far as High Barnet — a section that included East Finchley, with its new Holden station — and tube services began running to High Barnet in April 1940. But the Alexandra Palace branch and the section from Finsbury Park to Highgate remained unelectrified, and as the war intensified and resources were diverted to more urgent purposes, the LPTB was forced to suspend the remaining work indefinitely.

The Abandonment

The Northern Heights plan was never formally cancelled. It was simply deferred — first for the duration of the war, then for the post-war reconstruction period, and then, tacitly, for ever. The LPTB's successor, the London Transport Executive, reviewed the scheme in the late 1940s and concluded that the costs of completing the electrification — now substantially higher than the pre-war estimates, due to inflation and the deterioration of the unfinished works — could not be justified by the expected revenue. The suburbs served by the two branches were already developed, and the additional passenger traffic that electrification would generate was insufficient to cover the capital expenditure.

The decision to abandon the Northern Heights plan was taken piecemeal, station by station and section by section. The LNER — and, after nationalisation in 1948, British Railways — continued to operate steam services on the unelectrified sections, but the frequency and quality of these services steadily declined. The Muswell Hill branch, which had never been heavily used, saw its service reduced to a handful of trains per day. The section from Finsbury Park through Crouch End to Highgate fared little better. Passengers who had been promised fast, frequent electric trains found themselves waiting on draughty platforms for steam trains that ran late, infrequently, and to outdated timetables.

The closure of the unelectrified sections came in stages. The Alexandra Palace branch lost its passenger service in 1954, when British Railways withdrew the last steam trains. The section from Finsbury Park to Highgate closed to passengers on the same date. Freight services continued on some sections for a few more years, but by the early 1970s all traffic had ceased. The stations were boarded up, the track was lifted, and the cuttings and embankments were left to the slow encroachment of nature. The Northern Heights plan, which had been conceived as a great modernising project that would bring the benefits of electric traction to the suburbs of north London, had ended in abandonment and decay.

Highgate's Dual Existence

Highgate station occupies a unique position in the history of the Northern Heights plan. It is both a functioning station on the Northern Line — served by tube trains running through the deep-level tunnels completed in the late 1930s — and a derelict surface station whose platforms, built for the LNER services and prepared for electrification, have stood unused since 1954. The two stations occupy the same site but exist in different eras: the underground platforms belong to the modern transport network, while the surface platforms belong to the abandoned world of the Northern Heights plan.

The surface-level station at Highgate is one of the most atmospheric derelict sites in London. The platforms, though overgrown with birch and buddleia, retain their original infrastructure — the platform edges, the trackbed, the lamp posts, and the remains of the station buildings. The new platforms that were built as part of the Northern Heights programme, designed to accommodate the longer electric trains, are clearly distinguishable from the original Victorian platforms by their concrete construction and their slightly different alignment. The whole site has the quality of a place arrested in time — a station that was being prepared for a future that never arrived.

The underground station, by contrast, is very much alive. Trains on the Northern Line's High Barnet branch call at Highgate regularly, and the station handles a steady flow of commuters and visitors. The contrast between the busy underground platforms and the silent surface platforms above is one of the most striking and poignant juxtapositions in London's transport network. The two levels of Highgate station embody the two possible futures that confronted the area in the 1930s: the future that was realised, in which Highgate became a stop on the Northern Line, and the future that was abandoned, in which it would have been a junction for services to Alexandra Palace and beyond.

Ghost Platforms and Phantom Routes

The abandoned infrastructure of the Northern Heights plan extends well beyond Highgate station. The connecting tunnels between Archway and Highgate, built in the late 1930s and never used for passenger traffic, run empty beneath the streets of Highgate. These tunnels are structurally complete, lined with cast-iron segments and equipped with the basic infrastructure of a working railway — trackbed, drainage, and ventilation shafts — but they have never carried a train. They are among the longest and most complete disused tunnels in the London Underground network, and their existence has periodically prompted proposals for reuse as cycling routes, pedestrian walkways, or even underground farms.

The ghost platforms at several stations along the abandoned routes are another legacy of the plan. At Highgate, Cranley Gardens, and other stations, platforms that were built or extended for the Northern Heights electrification stand unused and decaying, their concrete surfaces cracked by frost and colonised by vegetation. These platforms are accessible, in some cases, from the functioning parts of the stations, and they are occasionally visited by authorised surveyors and engineers. But they are off-limits to the public, their entrances sealed with steel gates and warning signs.

The phantom routes of the Northern Heights plan can be traced on the ground by following the abandoned cuttings, embankments, and bridges that were built or prepared for the electrification. Between Highgate and Muswell Hill, the old trackbed runs through deep cuttings that were widened in the late 1930s to accommodate the planned double track. The bridges over roads were rebuilt to the heavier loading standards required for electric trains. The signalling equipment, though removed after closure, left its mark in the cable runs and signal box foundations that can still be found alongside the former track. The physical remains of the Northern Heights plan constitute a comprehensive and largely intact archaeological record of a transport project that was conceived, partially built, and abandoned within the space of twenty years.

The Parkland Walk as Legacy

The most visible and most loved legacy of the Northern Heights plan is the Parkland Walk — the linear park and nature reserve that follows the abandoned railway corridor from Finsbury Park to Highgate and from Cranley Gardens to Muswell Hill. The Walk was created in the 1980s, when Haringey Council, which had acquired the abandoned railway land, converted the trackbed into a public footpath and designated the surrounding woodland and scrub as a Local Nature Reserve. The Parkland Walk is now one of the most popular green spaces in north London, used by walkers, joggers, and cyclists throughout the year.

The Walk follows the route that the Northern Heights electric trains were intended to take, and much of the infrastructure that was built or prepared for the electrification is still visible along its length. The deep cuttings through the London Clay, widened in the 1930s, now shelter a rich woodland of oak, ash, and sycamore. The platforms of the closed stations — Stroud Green, Crouch End, and Cranley Gardens — survive as clearings in the vegetation, their concrete surfaces providing habitat for lichens and mosses. The bridges that carried the railway over roads retain their strengthened parapets and widened spans, mute evidence of the heavier trains that were expected to cross them.

The ecological value of the Parkland Walk is, in part, a consequence of the Northern Heights plan's abandonment. The railway corridor, left undisturbed for decades after closure, developed a rich and diverse ecosystem that included species rare in London — slow worms, muntjac deer, and over two hundred species of wildflower. The designation of the Walk as a nature reserve protected this ecosystem and ensured that any future use of the corridor would need to take account of its ecological importance. The irony is considerable: the Northern Heights plan, which was intended to bring modern transport to the suburbs of north London, has instead provided a corridor of wilderness through one of the most densely built-up areas of the city.

Unfinished Business

The Northern Heights plan remains, nearly ninety years after its announcement, a subject of debate and speculation. Proposals to complete the electrification and open the abandoned routes to passenger traffic have been made at regular intervals since the 1960s, and each time they have been rejected on grounds of cost. The most recent proposals have focused on light rail or tram-train services, which would require less infrastructure than conventional tube services and could potentially be built at lower cost. But even these scaled-down schemes face formidable obstacles — the ecological designation of the Parkland Walk, the residential development that has encroached on parts of the railway corridor, and the sheer cost of reinstating a railway on a route that has been abandoned for more than sixty years.

For the residents of Highgate, the Northern Heights plan is both a source of frustration and a badge of distinction. The frustration lies in the knowledge that their village was promised a comprehensive rail service that was never delivered — that the connecting tunnels beneath their streets, built at vast expense, have never carried a passenger. The distinction lies in the uniqueness of their situation: Highgate is perhaps the only place in London where you can stand on a functioning tube platform and look up at the ghost of a railway that was never completed, where the past and the future of London's transport system coexist in the same physical space.

The Northern Heights plan is, in the end, a story about the limits of planning and the unpredictability of history. The men who conceived the scheme in the 1930s — Frank Pick, Charles Holden, and the engineers and administrators of the LPTB — believed that they were building the transport system of the future, a system that would serve London for generations. They could not have foreseen the war that would interrupt their work, the post-war austerity that would prevent its completion, or the rise of the motor car that would undermine the economic case for suburban railways. Their plan, half-built and half-abandoned, stands as a monument to the ambition and the vulnerability of great civic enterprises, and as a reminder that the future is never as predictable as planners would like it to be.

*Published in the Hampstead Renovations Heritage Collection — exploring the architecture, history, and stories of London's most remarkable neighbourhoods.*