Opened in 1907 just off Piccadilly in Mayfair, Down Street station only operated as an Underground station for 25 years, closing in 1932 due to low passenger numbers. By that time, most Piccadilly line trains were already skipping the stop, which was only about 500 metres from each of the adjacent stations on the same line.
Wartime conversion
After its closure, the station’s two lifts were removed and the lift shaft was repurposed as ventilation for the railway. However, with the looming threat of war, the abandoned station was in 1939 selected by the Government for conversion in to a secret underground bunker for use by the Railway Executive Committee, to ensure continuity of railway operations.
Toilets and bathing facilities were installed in the passage leading away from the stairs while offices and meeting rooms were fitted in to the larger passage below, which previously linked the base of the lifts to the platforms. The lift-turned-ventilation shaft was sealed to protect against bombing and a new two-person lift was installed within the spiral staircase.
Walls were constructed along the platform edges in order to convert the platforms in to more usable space, while trains continued to run along the adjacent tracks. The eastbound platform was converted in to cooking and dining areas (two mess rooms with waiting staff) and a telephone exchange while the westbound platform hosted more meeting rooms and offices.
Sleeping quarters were installed on both platforms in order to reduce footfall arriving and departing the site, which could have attracted unwanted attention, and a small section of each platform was kept available for the forty employees to covertly board and alight from the drivers’ cab of passing Piccadilly line trains (while other passengers were none the wiser).
Churchill himself took shelter in this bunker at the height of the Blitz, in November and December 1940, as the purpose-built Cabinet War Rooms under Whitehall were neither deep nor fortified enough to survive a direct bomb drop. He slept on a camp bed in one of the mess rooms and most of the on-site personnel were not aware of his presence.
Post-war
After the war, most of the wartime fittings were removed, although the telecommunications equipment was deemed too bulky to extract, along with some of the bathroom fittings. There is still evidence of wartime signage on the walls, which were painted yellow to brighten the place up.
The station has now been returned to its role as a ventilation shaft for the Piccadilly line and can also be used as a passenger evacuation route (hence the modern signage). But most Londoners will only ever catch a fleeting glance of it, if they peer in to the darkness very carefully as they trundle past on the Underground, between Green Park and Hyde Park Corner.
Video tour
My short video montage of the tour includes footage of an Underground train thundering past us as we explore the abandoned platforms.