Due South: The Northern Line Extension 1926

A poster advertising the Morden extension. Image from London Transport Museum Collection.

Charles Holden’s work on the Piccadilly Line for London Transport produced some of the first and finest public modernist buildings in Britain. From the early stations at Ealing Common and Hounslow West, through to his first ‘box’ at Sudbury Town and onto his work along the Cockfosters extensions, Holden redefined the tube station bringing modernity to the suburbs. Holden had been recruited in the early 1920s by Frank Pick, at that point with the Underground Electric Railways of London (UERL), to design a new set of stations for the extension of what would become the Northern Line to Morden. At the time the line was part of the City and South London railway, one of the lines bought up by the UERL in its expansionist period, and earmarked for extension to try and increase passenger numbers. 

A poster showing the building of the new line. Image from London Transport Museum Collection.

An Act of Parliament was passed in 1923 to extend the line from Clapham Common to Morden, with an additional plan to build a surface rail to connect Morden with Sutton. This section was cancelled after an agreement couldn't be found with Southern Railways who had the rights to the train services there. Holden was tasked with designing seven new stations and a depot at Morden. Tunnelling for the 5 mile extension began on 31st December 1923 and took until September 1926. When completed, this section was the longest underground railway in the world. The stations for this stretch of line were Holden’s first complete group, although he had designed new entrances for Westminster and Clapham Common previously. Taking influence from the ideas of earlier tube architect Leslie Green, who had used a standard design that could be replicated at various sites, Holden devised a facade in three sections that could be adapted to any plot. Holden had the facade to be used at Clapham South built as a mock up in timber for inspection by the UERL directors at Earl’s Court exhibition centre.

The mock up station entrance to Clapham South, built at Earls Court. Image from London Transport Museum.

Unlike most of the later stations on the Piccadilly Line extensions, these new station buildings had to fit into an already existing urban fabric. Clapham South became part of the street parade along Balham Hill, initially as a standalone station, with an apartment block, Westbury Court, appearing over and around the station a few years later. This concept of selling the air rights to a building for development was common with a number of early tube stations, especially along the Central London Railway, at stations like Queensway, and was used at Morden on this extension. The next two stations on the line, Balham and Tooting Bec (opened as Trinity Road), each have two separate entrances, allowing access to passengers at busy road junctions. Tooting Broadway and South Wimbledon both have curved facades that fit into their respective street parades, a contrast to the other stations where the three part screens are angled. Colliers Wood has an angled facade with one street entrance. ​

An early sketch by Charles Holden for South Wimbledon station. Image from RIBApix.

The stations were built in brick with Portland Stone facades, all with large central windows to allow light into the ticket hall. These windows were decorated with coloured roundels, with all signage in the stations in Johnston font, a first step in harmonizing the visual identity of the underground, or UndergrounD as the station signs had it. Inside, the ticket halls were illuminated by ironwork art deco chandeliers, and were spacious and finished in a simple palette. Illumination was a large part of the new design. The stations were to act as adverts for the underground service at night, with light projectioning through the ticket hall windows with the roundel in the centre.The passageways and platform areas had tilework designed by Harold Stabler, with a mixture of white, green, grey and mauve.

One entrance at Trinity Road station (later renamed Tooting Bec). Image from RIBApix.

The modernity and clean lines of the Morden extension stations presented a clear contrast with those built for the other end of this railway, between Brent Cross and Edgware. These had been opened in 1923, only 3 years before the extension from Clapham Common, but were very different in approach, designed by the company's in-house architect Stanley Heaps in a quietly suburban manner, with pantiled roofs and colonnaded entrances. Indeed, Heaps’ department produced some designs for the Morden extension, very much in the vein of the Edgware section, with Neo-Georgian frontages. The UERL decided to go with the new spirit of the age, and the Morden extension stations opened on 13th September 1926 (apart from Balham which did not open until 6th December due to a labour dispute). Holden would go on to refine this station design at Hounslow West and Ealing Common, before moving onto to his Sudbury Box and then to the Cockfosters extension stations, and the Morden extension stations go on carrying passengers 100 years after they first headed south for the first time.