137. The Thames Tunnel

Welcome to episode 137 of the London History Podcast, where we share the stories of people, places, and events that have shaped our capital. I am Hazel Baker, CEO of London guidedwalks.co.uk. Today we are travelling beneath the surface, quite literally, into a story of extraordinary ambition, innovation and engineering genius.

Imagine Victorian London, the River Thames teeming with ships, and beneath it, a bold and unprecedented idea to dig the world's first tunnel under a river. This was no fantasy, but the work of a remarkable father and son team, Mark Isimbard Brunel and his son Isimbard Kingdom Brunel. Our guest today is Catherine McAlpine and she's the director of the Brunel Museum, which stands on the very site where this groundbreaking project took

shape. Many know that Isabel Kingdom Brunel was voted the second greatest Britain of all time in 2006, just behind Winston Churchill. But fewer realised that his father, Mark Brunel, the true architect of the Thames Tunnel, was French. Forced to flee his homeland during the Revolution, he made his way to New York before ultimately finding fame and fortune here in Britain. Will return to that remarkable journey in a moment. Catherine, welcome. It's a real pleasure to have you with us.

Thanks. For having me, I'm excited to be

here. Now we've got a lot of things that we need to cover today to absolutely jam pack it in, but with focus on 1st. I think the Thames Tunnel in itself, some people may have never even heard of it.

So what is it? So the Thames Tunnel was the very first tunnel under a river anywhere in the world and we take for granted now taking if you live in London, you're used to ping ponging from north-south under the river using the Underground. But actually 200 years ago in 1825, that was a complete novelty. People have tried to dig under the Thames to connect North and South and had failed. Unfortunately it hadn't worked.

So that's why the 10 panelists exciting and important because it was the world's first and we we take it for granted now. But actually there was no guarantee of success in 1825 that this tunnel would succeed, let alone it surviving 200 years later. Amazing, how long is the tunnel? Oh, it's not very long at all in terms of distance, in terms of

time. And to construct it, it took them 18 years, which was quite significantly longer than the three years that they had estimated because with no one having done it before, they sort of, you know, it was a great sort of finger in the air. Yeah. Three years, yeah, but ended up taking 18 to build and. Why did they choose that particular location then from Wapping to rather Hive? What was in it there?

Couple of reasons. One of the really important reasons is to do with the original purpose of the tunnel, which was to carry cargo from one side of the river to the

other. Rather high than whopping at that time was really important, kind of dot, lots of cargo coming in from across the world across the Empire coming into London, which was a huge port city and the only way at that point of crossing from north to South, the furthest east was London Bridge. There were plenty of bridges further up the river to the West, but the most easterly bridge was London Bridge. It would take a really long time

to get through traffic and nothing ever changes but to take things by load over the bridge, who could be a long time. And if you couldn't move your cargo, you had to run the ship through in the warehouses, which meant that it's much more to be susceptible to high risky and. Shrinkage. I think we call. It it's shrinking sprinkles exactly that that fantastic. So that was a real issue with sort of trying to get cargo from one side to put it in the dark, make it as convenient as possible.

The other reason is geology. And so one of the things that was really clever about the way that Mark Brunel designed the digging of the tunnel was he used the soft earth rocket hive to his advantage. They thunk and shaft into the ground and instead of digging, they built it onto the ground and let it think. So having that sort of accurate geology meant that they could supposedly meant that it would

be easier to dig this tunnel. So the location was one reason and then the sort of geology the other. And of course, this is going to be saving a lot of money, let alone the shrinkage. But of course, keeping anything in a warehouse rather than getting that product to market, it's going to cost money by just sitting there. So moving it as soon as you can was an advantage, which means they are saving money. So who was putting in the money

to build this tunnel? So it was definitely intended as

a commercial enterprise. It was meant to be this sort of toll tolled Rd. between the sort of the dock that you could move your cargo and you'd get lots of income from that. So lots of people saw the value of this from when Mark Brunel patented this cunning shield in 1818. In 1824, he gave a lecture to the Institute of Civil Engineers about this fantastic idea that he's had, and he got all these sorts of entrepreneurs, prime individuals, to invest in what became the Thames Tunnel Company.

So that's how they got their original funding. But unfortunately, because it was the first time they'd ever done it, it was not the most kind of plain sailing enterprise. It was really quite challenging and they kept running out of money. So they kept having to go back to the investors, getting new investors, getting more people in. They sold paper peak shows in order to generate income. They'd bring visitors to look at the tunnelling constructions, try and raise some of that money.

And actually at a point they they just completely ran out of money. I had to block up the tunnel. They're to stop construction. Construction stopped for about the 7-8 years at that point. Mark Brunel spent years petitioning, campaigning, writing letters. So anyone who would listen to say we need to finish this tunnel, we need to absolutely finish this tunnel. And then the Duke of Wellington eventually got involved and actually it was support from the government meant that they could

finally finish the project. So yeah, it had a, even though it was intended to be a sort of commercial project, it was really quite financially challenging the whole time of it, the whole 18 years of its construction. So what inspired Mark Brunel to undertake such an ambitious engineering project anyway? There was a real kind of commercial reason for wanting to dig, dig this tunnel to connect up the docks on either side of the river.

That was really important, and it made a lot of sense at that time. The thing that really made his project a success where others had failed was the tunnelling shield that he'd patented in 1818. And it was a way of protecting both the miners, the people doing the tunneling, but also protecting the tunnel itself as construction was happening. And the inspiration for that came from something called a shipworm, the humble Teredo Navales, which is not a worm at all, in fact it's a mollusk.

But Mark Brunel, before he came to London, was in Portsmouth. He was part of the Royal Navy and he saw first hand the kind of havoc that these sort of tiny mollusks would wrought on all the Royal Navy ships. So they would they'd dig hole using, using the kind of shells at the top of their heads to dig these holes in the Timbers of ship. But the really clever thing that they do is they then create a protective casing around themselves.

And that was the thing that previous attempts to dig a tunnel under a river had failed because there wasn't this sort of protective casing. So when Mark passages his tunneling Shields, it had this kind of wooden cover for miners to protect them for any kind of collapse from the soft earth. But behind them you'd have these brick layers come in and then they would line the tunnel with bricks, which meant it could withstand the pressure from sort of the water and the geology

above. So that was being inspired by nature is one of the great elements of the Thames Tunnel story. So his focus wasn't on really the the tunnelling as it were, because if we think of within working in the Navy and reinventing that block making system, his is actually the fixing a problem that no one else could. They could do the bit of the tunnelling, but it was the collapsing which they need some help with. You have a model in the Museum of this shield. Can you tell us a little bit

more about it please? It was made-up of 36 cells is what they were called. They're all, all about the size of a man. There were no women, as far as we know, involved in the construction of the Thames Tunnel, but you had sort of 12 cells along, so 12 men along and three levels, so bottom, middle and top. And each, each miner in front of them had a series of polling boards, so just wooden panels. And they'd remove each wooden panel, dig behind it by hand. This is all being done by hand

tools. There's no machinery. And all 36 of them would dig the width of a brick. And once they dug, they'd return the polling board, do the same with the next polling board. And by the time the whole thing had gone, they dug out the width of this brick. The whole thing would move forward on a sort of series of kind of cranks and screws and then the brick layers would come

in and do their level. So it's really painstaking work that they do. And yeah, if for the poor miners on the bottom, they're standing in Thames Water, which isn't that lovely to stand in now, but at this time it was, this is pre Basil Jet. This is, it's a, the Thames is an open sewer. But they were provided with boots by the Thames Tunnel Company. So that would that would help them.

The only thing is they did have to share those boots with all of the other miners, so you come into work and have to get into someone's stinky wet. Boots, I couldn't do that. Oh yeah, it's it's 100 times worse than bowling shoes. It's horrible. So these miners literally at the mud face, are these experienced miners? Are they nabbies? What's their skill set? So we think that they're sort of the miners and the tunnelers at the mud face. I really like that.

I'm stealing that. I'm going to use that. They were experienced miners from places like Somerset and they were employed for their skill in this work at the brick layers. I think were the most skilled employees. And then they were the ones that tried to go on strike because they weren't big paid enough. But you also had but lots of these, lots of labourers moving the spoil. So you had a bit of a sort of hierarchy, lots of different jobs, more, some more skilled,

some less skilled. When you're talking about skilled labour, did they have a little shanty town where all the workers live together? A lot of them lived quite lived locally. So the way that the kind of shift pattern works was the shield was always, it was always an operation, it was always going. So you have sort of eight hours on, 8 hours off. So you would finish your shift and then another miner would come and replace you and then you'd swap that way.

One of the things about the Brunels that some of the workers certainly appeared to appreciate is that they were very hands on employers. Isn't Bard King de Brunel. He was only 19 when the project started and he we've been talking about, you see the original sort of nepo baby because it was his dad got him the job and he then went on to be this incredible civil engineers. But he's really learned his craft under his dad on the

Thames Tunnel project. But he was, he was really, as far as we know, quite liked and quite well respected by a lot of the workers, not necessarily all of them because he was really hands on. He was a bit of a workaholic even then in the early days of his career. He'd sleep in the tunnel sometime. He just, he was like, I need to be back here in a couple of hours to check, so I'll just stay here. So yeah, it was a real, it was like a sort of mini town.

There were all these sorts of industries around the blacksmith forges, people making bricks, lots of things happening. It was very industrial and bustly. And if you come to the museum where the Thames Tunnel is, it's not like that today. It's like this sort of sleepy hidden London village. It's very quiet. But 200 years ago, it would not have been like that. You've had, you've had people shouting, swearing. Probably half of them were drunk.

They were given only. Yeah, the other half were asleep, presumably. But they, they were given whiskey as part of their sort of, presumably because the conditions were so hard. And it was, this is how you get people into work when it's such a kind of tough, challenging

job. Yeah. It's really interesting what you're saying about how some of the work has really appreciated IK being hands on because I was reading his obituary in the Engineer magazine and it was very picky saying he got too involved and too hands on. But of course written by people who wouldn't even think of being hands on. So you've got to keep the

workers happy. If you think 8 hour shift that is gruelling with the amount of stuff you're having to step through and work in. What about the air quality as well? Yeah, the air quality was not great. So if you think about it, the air's only coming from this sort of from this kind of shaft on the southern, on the Rotherhide side of the river. That's where your kind of air is coming in from. And the further under the Thames you go, the less good that air

quality becomes. Add to that the fact that you're stepping in Thames Water, which is basically human waste. And then also the other challenge that they had is as they were digging, they'd occasionally encounter sort of pockets of methane or other gases. And bearing in mind that this is entirely lit by gas lamp, that explosions were not uncommon. There were also times they'd encounter, I think certainly I think it was sulfuric acid.

It was certainly an acid. And we've got reports of people suffering from what was known as tunnel blindness, usually temporarily but sometimes not. So it's really not a this is Victorian health and safety at its best in in that it's completely non existent. And what were the Brunel's feelings? Thoughts on the kind of human cost? So that's, that's a really interesting question. Both Mark and Isenbard were worked very hard. They were very quite driven,

quite motivated people. And we have a there's an entry in Mark Brunel's diary from sort of Christmas one year quite early on in the project where he's I can't believe that they want Christmas off. I can't believe that they don't want. So he comes across as a real propest group, like a real sort of similarly was it's quite well documented. He was, he works incredibly hard ideas, modern ideas like self-care, very much not, not something that he would recognize.

But actually when the workers went on strike, this was a week into Isabad being resident engineer. So he's just been given his first pickle job by your dad. And then he's told, oh, now you've got to go and break this strike, which he does because that's his job and that's what he's been told to do. But in his sort of personal diary he write, I don't really understand why these people shouldn't be getting properly paid. They should be compensated for their work.

So it's quite interesting that kind of public, private persona as well. So yeah, they're quite, they were very involved certainly both Brunel's in the kind of day-to-day. But yeah, their attitude probably differed in the way that they responded to the people around them and. What about the public perception then with this tunnel evolving and they must have been seeing

adverts to invest et cetera? So I think like anything new and different and a bit novel and that there's an equal mix of kind of fascination and frightening. And I think people really saw that they, we've got reports of the local vicar in his weekly sermon after one of the floods saying that's what you get, but for digging towards the devil. And that there was this real sense that hell was down there,

why are you going down there? And so some people really were quite frightened by it. I thought it was really a bit beyond the pale. And other people were just completely fascinated. So that we've got some, we've got some amazing accounts of people coming to visit the Thames Tunnel because it was one of the ways that they generated income for the project. Mark Brunel didn't like it. He was worried. Interestingly, he was worried about the safety of the visitors.

He thought this is quite a risky project. I don't think we should be just letting you know, civilian down here. But the the actress Fanny Campbell came to visit and she was absolutely fascinated by by the engineering that was taking place. And another person that your listers might have heard of is Anne Lister. Gentleman Jack from the TV series tried to bring a date to the Thames Tunnel and the date

wasn't keen. I think the date never turned up but analyst that went on her own and has written about the the fascinating engineering that was happening. So there were lots of people who were really quite swept up in in this exciting project. And are there any particular artifacts or maybe stories in the museum that you feel really capture that spirit or drama of the Thames Tunnel project? So I think we've got some fantastic, we've got some fantastic kind of works on paper.

And one of the things that isn't on display yet, but will be is a this sort of beautiful cardboard model. It's handmade and it shows the tunnel in progress. It shows the tunneling shield, complete with little, absolutely tiny. It's about centimeter and a half miners and brick layers. And they're paper. They're absolutely, they're so delicate. And the one we have in our collection was Mark Brunell's.

But these were made and sold. There was a little guide book that went with them that is on display in the museum and they were sold to raise money for the project. They were, oh, look, we've made this lovely shiny the way that you might get a brochure now if you're thinking about investing in something instead, in the 1820s, you'd get this sort of beautiful little paper model. And I just think that sort of

captures. But it's also this sort of stylized view of what it was like that doesn't really capture the sort of grim reality. And I suppose that's one thing that all of the sort of images you get because of who produced them show this kind of relatively sanitized view. But we do have some amazing sketches as well that sort of show the tunnel after the floods that sort of give you a sense of some of the sort of danger that they were dealing with.

And how did the opening of this tunnel, if you've got this little shanty town, how did that turn and also wider area of London affect once the this tunnel was finally open? So I think the important thing with the sort of tunnel finally being open after after 18 years of construction and digging, unfortunately, even though it was always intended to be this kind of cargo tunnel to take horses and carts with cargo from one side of the river to the other.

In order to facilitate that, they needed to build what they referred to as the grand descent safts like we've got on the North and South side at the moment, but much bigger, which would have given you a much sort of a greater diameter for horse and carts to go down. By the time they'd finished the project 18 years later, there was neither the sort of finance available. That's the the lenders. The investors were just like, no, we're not giving you any

more money towards this project. It's already taken enough of my money and they there wasn't enough money to purchase the land to do those grander cents. But even if they had the money, the land had actually been sold. Don't ask me why they didn't at the beginning of the project, go, we need that land, let's buy it now. That was characteristic of the business decisions that they were making at that time. So because they didn't build those descents, which meant that

they could move cargo. When it opened in 1843, the Thames Tunnel opened as a pedestrian foot tunnel. So not the cargo tunnel it was meant to be. You paid a penny to go through it, which is much less than the sort of cargo tolls that they've been anticipating. So they needed to generate revenue some other way. So it opened huge fanfare in 1843.

It was really exciting. People had been waiting for this thing hugely popular, but actually they needed, they needed other ways of generating income. So it became this underwater shopping arcade that sort of you had people buying and selling wares. It became this just huge tourist attraction was really popular. And what about special events then? What was happening to get people down there?

The one of the other things that they did in order to make money and recoup these costs where they ran things for fancy fares. So they would have these sort of big extravaganza type events with all sorts of Victorian entertainment, including I think my there's two that are favourites for me. One is electricity. That was, see that was such a novelty at this point that was put on one of the posters as

something to come and see. And a woman, someone called the Mysterious Lady and she was a sort of mind reader type act. So she was a sort of proto Derren Brown in the Victorian era. So all sorts of interesting, interesting sort of Victorian entertainment you come and see in the tunnel. And what kind of inspiration did people take from this tunnel then? Did it have a knock on effect elsewhere in other engineering projects? In terms of tunnelling, one of

the things that we get asked at the museum is are you the Rotherhithe Tunnel? And we have to explain that the Thames Tunnel is now part of the Windrush line. It's actually part of the Overground network and the Rotherhithe Tunnel came later and is the road tunnel.

But what I think is really interesting about the different tunnel under the Thames, particularly in London, is they they took another generation for people to be ready to try to dig another tunnel onto the Thames. So there's quite a good chunk of time between the Thames Tunnel being started and finished and then people looking at the rather high tunnel, the Greenwich Foot tunnel, the Blackwall Tunnel, they were all completed within about 15 years of each other.

But it took a good sort of 50 years between the Thames Tunnel being completed to someone going, OK, I think we, I think we're ready for this again, because it was my take on it is that it was such a sort of undertaking and a bit of an ordeal that it took a long time for the next generation of tunnels to be dug. Today all tunneling projects have this that their foundation was laid by Mark Brunel 200

years ago. So the tunnel boring machines that made Crossrail possible, that are making HS2 possible, that made the Channel Tunnel possible, that's all a sort of modern version of Mark Brunel's tunneling shield. That's a really nice way to to put it. I remember reading a bit of a stat on a press release that we in Britain are leading the tunnelling engineering world and we have the only apprenticeships who tunnelling on offer. Go us. There you go. It's good. It's very important.

We would, if you, I hope that your listeners are after this thinking, start to notice actually when they go under the river a little bit more and actually there's sort of engineering that goes into that. Actually, that's a really good point. So you're talking about a Victorian tunnel, which how many trains on the Overground go through it a day? What about any restoration or anything that's been going on? Or are we really on borrowed time? Yeah, I think it is the sort of

last part of the story. So I always think of the sort of 10% of stories being so 3 chunks really. They're the construction. 1820s to 1843. There's it sort of shopping arcade and fantasy fairs kind of time sort of 1843 to the late 1860s. And then in the 1860s it was sold to the London Metropolitan Railway. It's got a second light as a train tunnel. This is this is in the very early days of the London Underground and steam trains. And so it was sold to the Metropolitan Railway.

It became the East London Line, which kind of ran from Whitechapel to New Cross. So it's not a very long line. And then in 2011 when the East London Line became part of the Overground, it all connected up and there's and it's now always the kind of Windrush on me. And I think something like 60,000 people go through it every single day, which is just a phenomenal amount in terms of restoration in the 1990s.

It was only in the 1990s, sorry, I state that it the tunnel itself was recognized as a sort of historically important feature that it's been, it had trains running through it for over 100 years by that point. But no one has really given it much thought. And there were plans to put shotcrete kind of concrete type material over the tunnel, over Mark Brunel's fantastic tunnel. And it was only at, I think the engineers were due on site at sort of 8:00 AM on the Monday

morning. And last thing on the Friday, the minister for Heritage signed a letter saying please don't put any shotcrete on Mark Brunel's tunnel. So I think it is shotcreted under the Thames in the section actually under the water. But the sections of the original tunnel on the sort of whopping and rather hide side are protective and you can if you stand up whopping. If you stand on the platform whopping and look back towards rather Hive, you can just about see the double arch of Marc

Brunel's original tunnel. I tell you what gave me goosebumps for 60,000 people a day going through the tunnel and one of them could be listening to this podcast. They might be on it now listening to it now. That would be amazing. If you are, just pop out on Brother Hype and come and say hi to her. Well, there you go. What aspect of the tunnel's

history fascinates you most? I just love that it's this story of adaptability and kind of perseverance and continuing against all odds because it was such a talented project. And then it took so much longer than they thought it would and but they completed it and they managed to make something really amazing. And unfortunately, both, both Mark and isn't bad died before before the tunnel was sold to the railways. They never saw it.

Kind of Second Life, there's a railway tunnel and I wonder how they would think 200 years later after they started construction that, oh, it's being used by 60,000 people every single day. This tunnel has survived and as it's adapted and it's become something else that's really genuinely useful.

And that's what I sort of love when people come into the museum and they we ask them how they got there and they're like, oh, I just got on the Windrush line and from, from white Tupperware, I'm like, you've been through the tunnel. You've already been through this fantastic tunnel and now find out about how it got there. So that's for me, I think is the story that I think is just so interesting about it. And what about a particular object or that really tells the

most powerful story? What is the to see other than the the shield model which I think is absolutely fantastic? Yeah, I love all the stuff to do with the construction. I love all the sort of drawings and the models, but I think what I also think is just so fantastic are these paper peep shows. And we've got one in our, one in our collection that and these are things that were sold to raise money for the construction itself and gave this idea of

what it was meant to look like. And we've got this absolutely brilliant one, which is quite rare because it's a double layered Peep Show and the top layer shows you the river. So it's showing you people on boats and some sort of ships, but then underneath you can see the tunnel itself. You can see the people walking through, having their conversations. And I just, I love that it gives you the full context of where the tunnel is, that it is under

the river. And sometimes you forget that, But just, yeah, the amount of kind of energy and effort and engineering that has to go into taking something for granted. I think it's quite lovely actually.

Your team are very busy at the moment with the creation of a brand new exhibit opening on the 12th of September. Can you tell us a little bit more about that? Yeah, absolutely. But we're really excited about this because we wanted to ask the question about how does Mark Grinnell, born and raised in front, has to leave, which is the French Revolution end up digging a tunnel in rather highs in southeast London? How do you get from Rouen in

Normandy to southeast London? And I think that I think that's such an interesting kind of premise. And it means that we get to put on display some of our most kind

of beautiful objects. And one of those objects which absolutely love is a pair of shoe buckles and a silver with jewels on. And they belonged to Mark Brunel. And I think they just give such an indication of his kind of personality and his character that this man who built this tunnel and this this really gritty engineering project loved a shiny shoe buckle. And it also really speaks to his political affiliations because

he was a royalist. It's one of the reasons why he had to leave France during the revolution. And the shoe buckles were a sort of sign of his political affiliation. And I and the fact that we have those and these tiny little objects can tell such a big story. I think it's just brilliant. I'm really excited to share those with with our visitors.

Oh fantastic. You have very kindly shared us some photos which we will be putting on the show notes in the video and of course on the transcript page of the website anyway. But of course, you can go and see these super shiny buckles with some really wonderful some of the oldest artifacts in the museum's collection in this exhibition, which is 12th of September to 15th of December 2025. We've also got some films that

we can enjoy. Yes, we're also doing a series of film screenings all about the French Revolution. So we've got Dangerous Liaisons, we've bought, we've got Marie Antoinette and Napoleon. So that's four weeks, Timber October every Wednesday. And the brilliant thing about that is we are screening them in our tunnel shop. So the big structure that was sunk into the ground that made the whole thing possible is now our major event space.

And you can come there and you can watch Marie Antoinette or Napoleon and understand just that amazing story of how did all these these events happening in a different country end up with kind of the world's first underwater tunnel in southeast London. And hopefully you're going to tell that the love story between Mark and Sophia.

Oh, absolutely, yes. So actually we will be doing some Valentine's Day events in 2026, all about the love story between Mark and Sophia. I think that's a whole other podcast their love. Story, I'm up for that.

All right, Catherine, thank you so much for joining us today. It just shows you, doesn't it, how important the tennis tunnel is and we don't really think about it, we just use it. Exactly. And if any of you lovely listeners would like to visit the Brunel Museum, then we have a treat for you. Catherine has kindly set up a super special discount code where you can use that when you book your tickets online and get 50% off museum tickets.

Simply go to their website thebrunelmuseum.com and click on Book Tickets and then enter this super secret code. Are you ready? LDNHI ST25LD NHIS T25. I'll put it in the show notes too. That's all for now, until next time.