TfL Explores New Northern Line Depot at Historic Totteridge & Whetstone Site

Transport for London (TfL) is considering a new depot on the site of a former railway horse hospital in North London as part of a long-term plan to run more trains on the Northern line.

The Northern line currently faces capacity constraints during peak periods. TfL aims to increase train frequencies to 36 per hour, which would require 45 additional stabling berths to accommodate the extra trains. Feasibility studies indicate that at least two new depots—one on each branch of the Northern line—would be needed. A potential site has been identified at Totteridge & Whetstone station on the High Barnet branch.

The location offers a unique mix of available land and historic significance. Originally opened by the Great Northern Railway in 1872, Totteridge & Whetstone station was later operated by LNER before being incorporated into London Underground in 1940. Adjacent to the station was a purpose-built horse hospital, designed to house up to 55 horses used for luggage transport, small freight movements, and horse-drawn buses in central London. The facility, which even featured a Turkish bath for treating the animals, opened in 1884 as a response to outbreaks of Glanders disease in urban stables.

The horse hospital eventually became obsolete and was converted into a Soft Drinks Works, later the Planston Works, before being cleared in 2017–2018. Nearby, a goods yard with a single siding operated until 1962, when it was replaced by a station car park.

TfL’s concept study proposes using the site for stabling 15 additional Northern line trains. One innovative approach under consideration would see the trains housed beneath new housing development. By excavating and leveling the site slightly, a podium slab could be constructed over the trains, allowing residential units to be built at street level. Early concepts suggest a mix of houses and low-rise flats around a central courtyard, with higher buildings along the railway edge to act as a sound barrier. Depending on design and land acquisition, the project could provide between 200 and 600 homes.

Although the idea remains at a conceptual stage, a Freedom of Information request notes that since the feasibility study in 2021, planning policies, legislation, and market conditions have shifted, meaning the housing element may not proceed as initially envisioned. At the same time, proposed relaxations of planning restrictions and prioritization of housing near stations could help future development.

Any new depot would likely include step-free access improvements to Totteridge & Whetstone station, providing a tangible benefit to passengers. The housing, if delivered, would act primarily as a subsidy for the depot construction, which remains essential to increasing Northern line capacity.

Another factor is rolling stock. Northern line trains are currently part of a PFI deal with Alstom, with units expected to reach 35 years of service by 2033. Although replacement is technically possible under national rail standards, London Underground typically extends train life by another decade before approving full replacement, which could affect the timing of depot use and the number of additional trains introduced.

TfL has emphasized that nothing is confirmed at this stage. The depot proposal represents a strategic option for meeting future demand while making use of a historically significant and strategically located site. Should it go ahead, the project could deliver both enhanced transport capacity and potential housing benefits for the Totteridge & Whetstone community.