London’s mysterious Tower Subway, which opened in August 1870 and was the site for the city’s very first tube railway even though that was a small narrow gauge line with just one carriage carrying a few passengers a time under the Thames, has been the subject of curiosity for decades because many spot its circular brick building at its entrance in Tower Hill, but no-one knows what’s down there these days apart from one picture that can be seen on Subterranea Britannica. About two weeks ago when there was snow the Urbex explorers The Secret Vault (who have a You Tube channel) and who are no stranger to many tunnels and other historical or industrial sites in the UK, managed to get down there and film the entire works. That was possible only because some worker left the main entrance in Tower Hill unlocked!
The circular brick building at Tower Hill is in fact a later addition during the 1920s after the facility was taken over by the London Hydraulic Power Company. The original entrances were cast iron structures, and the access to the subway itself was by means of lifts, later replaced by stairs. Like a lot of Londoners I have always wondered what exactly was concealed within that circular brick building. Was it a flight of stairs for example? We know now its a series of ladders that goes down a shaft around sixty feet in depth.
Its thanks to the Secret Vault we now have a comprehensive 21st century idea of how this 150 year old tunnel (its anniversary was last year) looks, for there’s been just that one photograph which showed us how it looked in the 1930s. One thing that struck me was how the downward shaft at Tower Hill was built about a third of the distance with cast iron segments but then the remainder to the bottom of the shaft was brick lined. Presumably the same technique would have been employed for the Tower Subway’s now missing southern shaft. I imagine this was a cost saving exercise, just as the waiting area at the bottom of the shaft, also constructed in brick, would have been too.
This view shows the remains of the waiting area that was in use when the subway carried a small train. (Compare with drawing below.) Screencap from The Secret Vault video.
According to the original description of the Tower Subway there was in fact a large space at the bottom of the Tower Hill shaft – a cavern which doubled as a waiting room and work area for the staff who operated the subway. That space is still evident at the bottom of the shaft and what a small area it must have been! Illustrations (such as that below) do give a sense of a larger space but when one sees the video its evident the actual tunnel was very small!
How the waiting area seen in the previous picture would have looked when the subway first opened in 1870. People are seen boarding the small ‘tube’ train which was operational for just a few months.
Its clear from the video the Tower Subway still retains the cast iron pipes that were installed for the London Hydraulic Power Company however these smaller pipes are now totally unused. Indeed at the far end of the tunnel one of the Secret Vault explorers shows the inside of one of these pipes, possible because the pipe itself has been severed and one can look into its bore. The tunnel still carry water mains (there are the the larger pair of pipes) as well as carrying cables for broadband or telecommunications.
The main tunnel under the Thames. The larger pipes are water mains and the smaller one was for the hydraulic power. Screencap from The Secret Vault video.
From the video its evident the tunnel itself under the river has needed strengthening in some places and more modern steel tunnel segments have been used. One surprise regarding this work to strengthen the tunnel (probably mid 1930s) has seen the use of tunnel segments with the initials LPTB on them! Clearly the newly formed London Passenger Transport Board allowed a number of its steel segments – intended for the extension of its tube lines – to be used in the Tower Subway. One wonders about the extent of involvement the LPTB had in regards to the Tower Subway…
LPTB tunnel segments used in the Tower Subway. The initials HPC stands for Hydraulic Power Company. Screencap from The Secret Vault video.
The modern section of tunnel that passes below More London en route to the shaft/headhouse in Vine Lane, just off Tooley Street. Screencap from The Secret Vault video.
At the far end of the original tunnel (on the south side of the river beneath More London just to the south west of City Hall – the site itself is marked by a tall lighting tower) there’s no trace at all of the former shaft that emerged into Vine Lane behind a public house. As expected, the tunnel does indeed continue on a new alignment and emerges into what is a low flat roofed utility building at the rear of the Unicorn Theatre near the top end of the current Vine lane.
The Tower Subway’s headhouse just off Vine Lane. Author’s photograph.
As well as the extant circular building at Tower Hill, the other end of the subway emerged roughly where the tall lighting mast can be seen on the other side of the river. Author’s photograph.
Looking up the shaft leading to the newer headhouse behind the Unicorn Theatre in Tooley Street. Screencap from The Secret Vault video.
The Secret Vault Explorers were stopped by the police when they emerged from the subway at Tower Hill. Both explorers had known the police were waiting at the top of the shaft because one of the guys had gone up to see the exit was clear. He decided to retreat and try and leave the tunnel by the other entrance just off Tooley Street! The main guy however decided to ‘face the muzak’ and he demonstrated to the waiting officers that there had been no ill-intent (such as terrorism etc.) As quoted on their You Tube channel, he says ‘I encountered Police on the way out who thought I might be a terrorist trying to get into the Tower Of London or the City Hall Of London. Thankfully they were polite and friendly and accepted that I was a youtube content creator and let me go…’
The Secret Vault’s latest video is certainly fascinating and it has answered several questions I have about the Tower Subway as well as giving me new insight about it too. Clearly there will be others too who will now have to update their histories of the Tower Subway! The video surely shows for the first time a complete view of the entire tunnel and its access shafts and how the whole thing looks today – most of it quite decrepit and definitely showing its age I must add. It does however show us, that despite this very tunnel being the location of London’s first ever ‘tube railway’ (a short lived line that worked for just a few months – the tunnel was ultimately used for pedestrians until the nearby Tower Bridge opened.) No doubt it was a considerably claustrophobic subterranean passage – and one that was much smaller that those pedestrian under river thoroughfares at Greenwich and Woolwich!
The full video from the Secret Vault is shown below. If you prefer you can always watch it on You Tube itself – I’m not that fussy!
There’s a good history and pictures of the Tower Subway on Subterranea Britannica.
Brief update 26 February 2021
The entrance to the Tower Subway has been reinforced with additional measures, these being a pair of padlocks at the top and bottom of the door. Clearly the authorities thought one old style keyhole lock wasn’t secure enough as maintenance staff could have simply closed the door and left the site not realising they had not done that one lock.
The doorway at Tower Hill is now secured by an additional pair of padlocks. Author’s photograph.
In essence I think maintenance staff will now have to secure the site by means of all three locks. I would also think the new padlocks serve to provide a visual deterrent of some sort. These locks are exactly the same as that pair of Master padlocks which are used to secure the entrance to the southern end of Tower Subway. These locks have been present possibly since that headhouse was first constructed. The new pair of locks for the northern entrance cost around £26 (Screwfix at £12.99 each) and the hasp and staple latch, evidently a generic make, somewhere between £4.99 and £9.99.
Close up of the bottom padlock on the Tower Hill doorway. Author’s photograph.