On the north bank of Thames, and alongside the Tower of London, is a frequently photographed and written about structure, over what was the entrance to the Tower Subway, here with the ice cream van that seems to be there most days, selling to those visiting the Tower:

The story of the Tower Subway starts with an Act of Parliament which was passed in 1868 for the new tunnel at Tower Hill, urgently needed as the only route across the river to the east of London Bridge was the recently completed Thames Tunnel at Wapping (see this post), and during the latter half of the 19th century, the population of London, as well as the volume of trade passing through the city, the number of docks, and the amount of industry, was growing very rapidly.
People needed to cross the river. To get to work, to transport goods, for meetings and commerce, and with the expansion of London to the south of the river. There was a mile and a half gap between London Bridge and the new Thames Tunnel at Wapping, which, along with very busy streets, created a very considerable barrier.
It was estimated at the time that a million people lived on both sides of the river below London Bridge, and this population was continuing to grow.
The proposed tunnel would consist of shafts, between 50 and 70 feet deep on either side of the river. The north access point at Tower Hill and the southern alongside Vine Street.
A hydraulic lift would raise and lower up to ten passengers at a time, and at the bottom of the shaft there would be a small waiting area, with a cable pulled carriage transporting passengers between the north and south of the river.
It was estimated that the cost would be £16,000, it would take eight months to complete, and the engineer for the project was Peter William Barlow, who was also the engineer responsible for the first Lambeth Bridge..
Construction of the Tower Subway started in 1869.
Where today, there are plenty of photographs and video of major construction projects, in the 1860s, the only way to illustrate such a project was to lower an artist down to the tunnel, and in September 1869, an artist working for the Illustrated Times found himself in the tunnel, and reported that:
“After getting into the pail I was lowered some fifty feet, turning round and round like a joint of meat at the fire. A trolley was waiting at the bottom; I seated myself, and was propelled by a stalwart navvy. During my progress through the tube I heard the sounds on the water above; by candle light I could see the great strength and perfectness of the work, ribbed like the skeleton of some huge snake. Presently we stopped to allow a trolley laden with clay to pass; then we arrived at the telegraph station – a very complete arrangement, to enable men below to communicate with those above. While at the top of the shaft I had an opportunity of seeing it at work. Tinkle, tinkle goes a small bell. ‘More nuts’. Answer ‘All right’. Tinkle twice, tinkle three times. ‘Send down castings’. Answer, ‘All right’. Tinkle four times, ‘More air’, Answer. ‘Can’t have it yet; taking in lime’. And so on, saving a great amount of time.
The men having thrown out the clay in front of the shield, I saw them advance it. It was easily done with three or four men working the screws to the width of the casting; one of which is placed in the curve of the shield at the bottom, bolted it, and placed the side pieces, and finished with the top, screwing them all to the last ring of the tube. The clay through which they are passing is about the consistency of caked chocolate, the pick leaving a shining surface upon it. The men have plenty of air, but by candle light look weird and strange.”
The use of a shield was key to the success of the project, as was the use of iron for the rings forming the tunnel.
On completion of the tunnel in 1870, the speed and ease of construction supported the view that iron would allow considerably larger tunnels to be constructed, and some newspaper reports on the opening of the Tower Subway stated that: “Considering that a project has been recently discussed for carrying a subway from England to France, it would be ridiculous to go into raptures over the completion of a Tunnel from Tower Hill to Tooley Street”.
By the end of March 1870, the tunnel was being tested with invited guests. The mechanism for taking passengers between the two entrance shafts was described as a carriage, able to carry 14 persons, with a door at each end. A wire rope was attached to the carriage, and to cylinders at each end of the tunnel, with the cylinders being worked by steam power.
The tests though, demonstrated the limitations of the method, and the recurring problems that would result in the removal of the carriage, a short time after opening.
On one of the trials, the wire rope was unable to bear the strain, and snapped, with the carriage and passengers being left, midway through the tunnel. It took a while to repair the wire rope, the trial started again, but after a short distance, the wire again broke.
The trials ended soon after, with a stronger rope ordered for the opening of the tunnel.
The interior of a carriage in the Tower Subway:

Attribution and source: UnknownUnknown, Public domain, via Wikimedia Commons
The northern entrance to the Tower Subway as seen today:

The first commercial use of the Tower Subway, was late in the afternoon of Tuesday, April the 12th 1870, when paying freight was hauled through the tunnel, and the next day is was opened, with very little ceremony, for passengers.
By the end of 1870 though, London’s papers were starting to report on the Tower Subway as being a failure, with numerous problems with the lifts taking people up and down the shafts, and passengers often being stuck mid-way through the tunnel.
Such were the problems with the complexity and reliability of the lifts and the carriage, that the Tower Subway was soon converted to foot passenger use, and just over a year after first opening the following account is of a trip through the tunnel after conversion to a walk-way, by a correspondent of the London Daily Chronicle on the 30th of June, 1871. The account provides a view of what a walk through the tunnel would have been like (with the caveat that this was written by a journalist, so probably a bit of over emphasis on the poor conditions):
“I have just availed myself of my first opportunity of inspecting the work over which, not a great while ago, such a deal of enthusiasm was expended – the Tower Subway.
I found the City terminus under a conical little shed, planted in the midst of an expanse of rough flag stones, in very good keeping with the adjacent old Tower, and with the antiquated old gentlemen who strut around in medieval toggery within the Tower railings. I had made up my mind to descend luxuriously – in a sort of lift, comfortably fitted up – and after a railway rush under the river, to make a triumphant exit on the Surrey side. It appears, however, that the lift and the railway carriage didn’t pay, and so were of necessity abandoned. Instead of the lift I found a narrow, dimly-lighted spiral staircase, up which, as I descended, came an unsavoury odour.
The gas lights were most ingeniously placed exactly between the landings. At the bottom I found a turnstile, presided over by an unhappy little boy, condemned to spend in damp and gloom and foul air no less than fourteen hours and a half out of his twenty four, and that seven days a week. I commenced groping my way through what looks like a gigantic rats’ hole. lighted up at intervals with gas jets. The narrow rails on which the carriage ran at one time are still down, and serve admirably to trip up passengers and knock their heads against the girders whenever two have occasion to pass each other. Here and there the footpath is wet and sloppy. This is, perhaps, unavoidable, but it is certainly an unpleasant feature.
The safety of the structure is, no doubt, beyond question; but the leakage very forcibly suggests the idea of thousands upon thousands of tons of water overhead, and one is by no means sorry to reach the other turnstile, where another young unfortunate sits at the receipt of custom. Passengers are supposed to spend six minutes in performing the journey. This, I presume, doesn’t include the time which, on emerging into the open air, I, at least was compelled to spend in holding on to the nearest lamp-post.”
The following illustration shows the tunnel being used as a walk-way:

Attribution and source: Public Domain, https://commons.wikimedia.org/w/index.php?curid=298484
The tunnel continued in use as a walk-way, however in 1886, the project that would bring about the demise of the Tower Subway as a method for people to cross the river, was starting to appear just to the east, with the start of the construction of Tower Bridge.
When Tower Bridge opened on the 30th of June, 1894, use of the Tower Subway collapsed. With Tower Bridge, there were no shafts to descend and ascend, no damp, gas lit tunnel to walk through, and the new bridge was free.
The owners of the Tower Subway tried to sue the Corporation of the City of London for loss of tolls, and in September 1897, a shareholder meeting of the Tower Subway Company was held at 21 Great George Street, Westminster, when it was discussed and agreed that:
- The arbitrator between the Tower Subway Company and the Corporation of London had awarded the company compensation of £11,000;
- That the Tower Subway was to be sold to the London Hydraulic Power Company for £3,000;
- And that the Tower Subway Company was to be wound up.
The name of the London Hydraulic Power Company still circles the Tower Hill entrance today, which is not the original entrance building to the subway, but a 1926 construction over the shaft. At the time of the purchase of the subway, hydraulic power was used to power much of London’s infrastructure – cranes across the docks, lifts, even the curtains in theatres were power by hydraulic power.
The tunnel was also used for the water supply of the city, and in September 1898, workers were laying 20 inch diameter iron water main pipes through the tunnel, connecting a growing network on the southern and northern sides of the river.
Much of this work was aimed at fixing what was called the “East London Water Famine”, as there were insufficient supplies of water to service the rapidly growing population of east London.
Pipes through the tunnel connected to the network of the Southern and Vauxhall Water Company to the south of the river, and from the northern exit of the subway, the 20 inch pipes ran to Leman Street, where they connected with the mains network of the East London Waterworks Company.
The following image is from the 1961 book “London Beneath the Pavement” by Michael Harrison, and shows water pipes running through the old Tower Subway:

As a diversion, I have mentioned a number of times over the years, how I find the journey of books fascinating. This is my copy of London Beneath The Pavement, and in 1961 is was owned by Richard J. Waller, who wrote his name inside the cover:

I do not know whether it was the same owner, but 30 years later, in 1991, either Richard J. Waller, or a later owner had cut a notice of the death of the author from the Daily Telegraph, and pasted it inside the book:

A very small thing, but part of an individual book’s journey through multiple owners.
Part of the title to the post is “Mystery of the Southern Entrance”, and now I need to explain why.
From the round brick entrance at Tower Hill, the Tower Subway heads south, crossing the river towards the new developments on the south bank of the river:

Openstreetmap has the Tower Subway Access marked (in my red circle in the extract below © OpenStreetMap contributors):

And leaving Tooley Street, there is a small, square building where the map has the subway access. A photo of this structure is also shown on Wikipedia as the entrance to the subway:

The original entrance on the south bank was demolished in 1990, and this building does indeed look like an entrance to a place that would hold utility services:

However, I am not sure whether this is the site of the original entrance.
Firstly, it is a reasonable distance back from the banks of the Thames, further than the distance between river and northern entrance. Why would this extra distance have been necessary?
Secondly, newspaper reports often mentioned the southern entrance was next to the Vine public house in Vine Street, which the 1895 Post Office directory confirms:

In the following extract from the mid 1890s OS map, I have highlighted key features as follows:
- Green arrow, track of the Tower Subway
- Red arrow, small building next to the Vine which could have been the original entrance
- Yellow arrow, the Vine public house
- Blue arrow, location of the new building that today is often mentioned as the entrance to the Tower Subway

(Map ‘Reproduced with the permission of the National Library of Scotland)
As can be seen in the above map, the building at the blue arrow is a good distance from the banks of the river, and there is a small building next to the Vine, as mentioned in newspaper reports, and in the Post Office Directory.
Jump to the 1950 revision of the OS map, and we can see the track of the Tower Subway (green arrow) and although the Vine has gone, there is still a small building where the possible entrance next to the pub was located (red arrow), and at the point of the possible entrance building today (red circle), there is nothing marked:

(Map ‘Reproduced with the permission of the National Library of Scotland)
Looking at the location of the red arrow in the above map in more detail below, we can see the parallel dashed lines of the track of the Tower Subway terminate at the small building which was once next to the Vine public house – not at the location of the possible entrance today:

(Map ‘Reproduced with the permission of the National Library of Scotland)
To add to the confusion, there is a sign on the building that is the possible entrance today which states that the building is maintained by Jascom.
A couple of years ago, Vodafone published a video about the tunnel, and a Project Manager from Jascom is featured in the video, so based on this, the small building we see today must be the entrance to the Thames Subway.
This fascinating video is below, and shows the condition and use of the tunnel today:
But I still cannot get away from the references to the entrance being next to the Vine public house, and the track of the tunnel terminating at the small building closer to the Thames, which would also make sense as the work needed for the additional length of the tunnel to the building we see today, would have added to the overall cost of the project.
There is another option. The possible original location of the tunnel entrance today, would be at the south western end of the paved open space, to the south west of the old City Hall building, between Fire Station Square and More London Place. Is it possible that an additional length of tunnel was dug when this area was redeveloped to move the entrance away from the open space?
As the video states, the tunnel was purchased in the 1980s as part of the overall London Hydraulic Company pipe and duct network by Mercury, one of the 1980s challengers to British Telecom.
Mercury was taken over by Cable & Wireless, and then Vodafone took over part of the business which included the old Thames Subway, and as well as water pipes, the tunnel today now carries communications cables.
As is often the case, you start digging into a part of London’s history, and you are left with more questions.
I have messaged Jascom to see if they can clarify, however whether the small building is at the correct place, or whether it was further to the north, the Thames Subway is a fascinating story of one of the many methods of bringing the north and south banks of the river closer together, as London expanded, and the population, trade and commerce of the city grew.
The Tower Subway is also a story of how infrastructure evolves, from the original plan to carry passengers, then hydraulic power pipes and water supply pipes, and today communication cables have been added to the mix.
If you are interested in more history of Tower Hill, I have written a post on the Tiger Tavern at Tower Hill, click here for the post, how Tower Hill has changed over the years, click here, and for Johnny Eagle, the Tower Hill Escapologist and Strong Man, click here.