How The Channel Tunnel Works

Let's dive into the engineering and construction of the Channel Tunnel on its 30th anniversary.
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It is a challenging endeavor to put any tunnel below the sea, and this monumental project faced some monumental hurdles. From complex cretaceous geology, to managing air pressure, water pressure, and even financial pressure, there are so many technical details I think are so interesting about this project.
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[@PracticalEngineeringChannel]

🚆 Have you ridden through the Channel Tunnel? What was your experience? 💡 Don't forget to claim your free trial at brilliant.org/PracticalEngineering

[@gus473]

Haven't been, although one of our subsidiaries made parts for the Tunnel Boring Machines! Seems like ancient history now! 😎✌️

[@MrLexhoya]

Once, with the family. I didn't expect it to be that fast. I would do it again, if I travel to UK by car.

[@startide]

Been on it several time, not much to see. I remember when it first opened and I was traveling to the UK people asked me if I could see the fishes :D

[@robertheinrich2994]

no, I haven't, I would like to. but I had a ride on the hovercrafts. that was quite impressive 😀

[@cda32]

I've taken my car through "Le Tunnel" as its now known. It's an expensive option on the surface, but I prefer it for convenience since you have your car on the other side, and it is very fast. Only 20 minutes really if you exclude the boarding process which is surprisingly fast and efficient (ferry is like 2 hours depending which route). You drive onto a double story train, the train cars seal off between each other, there's 100 safety announcements, and you're on your way. You do not leave your car ever. I think what's more fascinating is that you're going between a right hand drive country to a left hand drive country, you could do a video on the associated road infrastructure which transitions you between the two so seamlessly.

[@Ven100]

As someone who's taken the Eurostar several times, I can assure you it's far better than flying. There's a reason why those fights have to be cheap because they have to undercut the price of the train. The train will offer far more comfort, space, and amenities than those typical short haul airliners. Being able to leave downtown London and be in downtown Paris within 2 hours is amazing. Depending on the price of the ferry, the automobile driver can choose to take the train all the ferry. I once traveled from London to Munich all by train. First leg was the Eurostar to Paris and then I took a TGV from Paris to Munich. Sure, I could have saved time by flying straight from London to Munich, but the train trip was far better. During my stopover in Paris, I was able to explore the city before catching the next train.

[@FirmCat]

I agree on the flying bit. But when traveling by car, the ferry is far superior to the shuttle. It is often cheaper, takes about the same time,including wait times, loading and unloading, and on the ferry you can walk about and have lunch.

[@-slasht]

When driving, the tunnel may be a bit more expensive than a ferry but if the sea is a bit rough on the day you travel you get to spend a good hour or so wishing you'd taken the train :P

[@MonkeyJedi99]

Also, both the planes and the ferries are petroleum-powered. The electricity that runs the trains COULD be from petroleum, but it could also be from other sources, particularly wind. And the electricity doesn't care if and when it comes from another source. So, if we find out tomorrow that putting a Ficus and a house cat in a room with an aluminum floor generates massive amounts of electricity without harm to the plant or the cat? That will be powering those trains.

[@Marco-rx4cg]

Just took the Eurostar from Paris to London a week ago. It's absolutely great, no doubt about that. However, with the cheapest available one-way fare for that day being 120€ and flights starting at 27€, it's certainly not competitive price wise.

[@JohnADoe-pg1qk]

@@-slasht 🤮😁

[@startide]

One thing we can see in the video (well if you looked in the background) is that the service vehicles actually have dual cabins for driving. Since they can't possibly turn around in the service tunnel, crew members simply change cabin and drive the other way.

[@ChiSa123]

If they could it would probably end up like the Austin Powers scene where he turns around in the tunnel! 😂 This one: kzbin.info/www/bejne/f3jMgoJ5jZ6ImK8si=-deIcM8cXPF4C-rG

[@s.i.m.c.a]

it coz there were no tech of rotating front and back wheels ..i.e. crab turn or how it's called

[@PizzaPowerXYZ]

​@@ChiSa123KZbin didn't auto remove that link? Crazy

[@ChiSa123]

@@PizzaPowerXYZ Probably, because it is a KZbin link to a KZbin video. If it was something else, maybe they might have.

[@NavinF]

@@ChiSa123 People post links to their own videos on random comment sections all the time. That's why youtube usually hides any comment that contain links, even if it's a youtube link. You got lucky with the spam filter

[@rennaaa6667]

I wish we'd see more mega infrastructure projects like that. The moment they met in the middle and drilled trough to the other tunnel must have been such an amazing moment for the people that built it.

[@mmckenzie9367]

I wonder if there was a pressure differential in the two tunnels. Was there a puff --or a blast-- of French air in the face of the Brit when they broke thru? Just asking.

[@HDL_CinC_Dragon]

@@mmckenzie9367 To me, it looks like there was a pressure differential. In some of the shots you can see clothing fluttering, such as at 9:38.

[@KyrilPG]

A few megaprojects in France right now : There's the Lyon - Torino line currently being built, with a gigantic base tunnel between France and Italy (duh). There's parallel digging and there will be deep "meeting" too, at a point located close to the vertical of the mountain peak. The base tunnel will be slightly longer than the Brenner Base Tunnel. And also the Grand Paris Express, a humongous metro expansion (200km, 68 new grandiose stations, 4 new fully automated lines including a circle one that is the longest fully underground line, plus 2 extended lines). Some stations have more than 50 escalators, about 9 kilometers linear of platform screen doors on the circle line only... First bits are set to open this spring 2024, first section of the huge circular line in autumn 2025, then one or more sections every year till 2030 or 2032. And there are also the recently relaunched high-speed line developments, especially in the South, like the Southwest triangle from Bordeaux to Toulouse and to Spain on the Western side of the Pyrenees. As for the question : when they pierced the hole at the meeting point there was no blast or sudden rush, but a constant rush of air as the tunnel acted as pipes. You can see it on archive footage with the flags at the meeting point.

[@raffriff42]

Imagine that scene playing out in the many aqueduct tunnels of ancient Rome.

[@bordershader]

In my school they wheeled in a big telly so we could watch the moment it happened and they met and shook hands. It was amazing!

[@billymcmedic4221]

Another nice detail about the channel tunnel is that it allows new built trains to be transported from mainland Europe to the UK without needing to be loaded onto a boat and floated across, resulting in lots of faffing around to get them on and off, simply hook the train to be delivered to one of the tunnel freight locomotives and they can be pulled through. It’s how the new Mersey rail and Tyne and Wear metro trains are being delivered from stadler in Switzerland, they get pulled by train to Calais, transported through the tunnel, and hooked onto another train for final delivery (usually a pair of Down geared HST powercars)

[@INCDZONE]

wow that is interesting, i thought that rails tracks where different in size from UK to EU or was it thinking the power issue. Still makes total sense and saves time as you say.

[@MarioFanGamer659]

@@INCDZONE You're thinking of the loading gauge which causes British trains to be narrower than their Europen equivalents. Rail gauge is only an issue in Iberia (unless the tracks are high-speed), Finnland and East Europe which use a wider gauge than standard gauge. Power is a legitimate issue but only within South England and HS1 provides a connection to the rest of the UK even then, modern locomotives are built to be multimodal.

[@stewarthome3729]

​@@MarioFanGamer659⁰

[@neatodd]

Good video. I used to work for Eurotunnel. I could leave my flat in Folkestone in the morning, go through the tunnel to France for a meeting and be back in my office in the UK by lunchtime (sometimes taking the opportunity to buy a few bottles of French wine in a local supermarket before returning). It's amazing to me that the tunnel has made it possible for freight trains to run all the way from China to London.

[@user-zw5jj2uf1p]

>China to London omg that's true. That's crazy. Instead of "there's a person who traveled from London to Beijing" in the first millennium, this millennium sees "there's a train that traveled from Beijing to London"

[@gus473]

Possible, true, but do they, actually? Regularly? 🤔 (This possibility never even crossed my mind! 🤦)

[@aidandillon9520]

You can take a train from London all the way to Singapore! It takes about 40 days and is 10,855km. To travel by train from London in the United Kingdom to Singapore, the main route leads via France, Germany, Poland, Russia, China, Vietnam, Cambodia, Thailand and Malaysia.

[@Abrothers12]

@@aidandillon9520a marvel of our interconnected world

[@fullnuclearbreakfast]

@@gus473 Yes, I'm not sure how regularly but it has been done. It runs from Yiwu, which is not far from Shanghai, there's a route to London which is 12,000km and one to Madrid which is 13,000km (the longest rail route in the world). They do have to change gauge a couple times though.

[@ianp1986]

When I was a kid, I was devastated when I found out it wasn’t a glass or Perspex tunnel laying on the sea floor so you could see out. Still am, to be honest!

[@gert-janbonnema]

I had the same thought about the metro of Rotterda that goes under a large river, but without the glass. More like a very long submarine with glass windows. I know better now. But you can still see the change in the walls when you go under the river.

[@greentravels2850]

I went on the Eurostar a few years ago. Using what I remember was the official app and/or website; there was a VR type feature available when you were in the tunnel. It basically showed what you were thinking about: traveling through a glass tunnel with water all around you and even fishing swimming by! It was pretty cool.

[@CJizzleJ]

I remember asking my parents if we would see any sharks on our journey. I was so disappointed.

[@skylined5534]

As a kid I also assumed it would be like a huge underground aquarium of sorts 😂

[@baptistebauer99]

That's an idea right there!! In the middle of the channel it would be completely unfeasible due to the pressure, no transparent material would sustaint it and it would be almost completely dark anyway. But at both ends of the tunnel, going into the sea... that would be so so awesome

[@ryanm.191]

I’m from the U.K. and am right now currently skiing in Austria having taken the channel tunnel here and will use it to return. I have used it twice a year for twelve years and the logistics behind it all is immeasurable. The trains are very punctual, they’ll load more than 100 cars in 15-20 minutes and provide this service four times an hour in off seasons and six to eight times an hour in peak holiday seasons. And even though it was designed now almost 40 years ago, the trains and every looks modern still

[@Kabodanki]

Don't forget to respect people in the countries you go through, don't act all englishy over there

[@ElusiveTy]

​@@Kabodanki While you have a half point, this applies to every single person from any country visiting any other country, not simply Brits. Also, they said they're from the UK... Not England. They may be from England but you've made an assumption. To highlight how abrasive your comment is, let's swap out the words. 'Don't act all Chinese-y over there' 'Don't act all French-y over there' 'Don't act all American-y over there' 'Don't act all Middle Eastern-y over there' Again, you have a point only in so far that EVERYONE should respect the people and customs of wherever they're travelling. You've assumed someone is English and tried to single that out, also going on to assume that this person is not only English but would somehow be too 'English-y', whatever that is. And no, I'm not English or from anywhere else in the UK. Not that that should invalidate an opinion.

[@Maximilz]

Mine was 40 minutes late last week

[@richardprice5978]

wishing car-passenger-train services would be easier to access in the USA between major cities in the USA 🇺🇸 as it would be nice to have a option to ride instead of driving ( cramped up ect ) 12 hours one-way ect uk 🇬🇧 and Florida showcase what's possible

[@benkai343434]

@@Kabodanki I understand there's always a temptation to judge your brothers and your sisters, but it's better to refrain from such judgments if you can, lest the devil take control of your tongue.

[@gjwdavies]

My father was a Civil engineer on this project. Still one of his favourites. He has a lot of great stories about the construction. Can't wait to show him the video.

[@reneeantwi-boasiako3974]

Amazing!

[@scottbelter1972]

I would love to hear his responses to the video.

[@fonkbadonk5370]

I once took a weekend trip from Germany to London with a travel agency. They just drove their big coach into one MASSIVE train, and then into the tunnel we went. Absolutely incredible. And the ride was suuuuper smooth. There was just one spot where we felt an ever so slight bump, the rest not a single vibration. It was also cool to get off the coach and walk around in that huge rail car, meeting people from other coaches.

[@bwhog]

That bump, I bet was the stated piston effect when you passed a train going in the other direction.

[@becauseimafan]

That is so cool! I've always been interested how our underground Metro system (subway) works here in Montreal, Canada, and the idea of travelling the channel tunnel sounds so cool!! Does coach mean travelling by bus? When talking about travel in English, I usually see coach as a category of ticket and seating (like first class is most expensive for more comfort and features, and coach is least expensive for the least features and comfort). Unless it's about _historical_ travel by horse pulling a carriage or buggy, then I see it often referred to as coach! But unless it was a _very unique_ travel agency, I don't think that's what you meant, haha 😁 But if it was I need to know the agency's name immediately because that would be _fascinating_ to look up!

[@hydrolifetech7911]

​@@becauseimafancoach is bus in this case

[@Jablicek]

@@becauseimafan I've done this trip a few times (maybe 30?) in the last 20 years, and all but one has crossed the Channel through the tunnel. (In the UK, we call it "the Tunnel" not the "Chunnel" - there's no better way to look like a tourist :D ) The coach is simply a long-haul bus but with an onboard loo, USB charge points, better seating (usually - I've had some Flixbus journeys that wouldn't have been legal), curtains on the windows, more luggage room, and infrequent stops. The bus generally leaves and arrives on time, there's no passport control when you board (that's taken care of in Folkestone or Calais before you go through the tunnel), drivers only want to see your ticket and ID to show it's yours, so boarding is MUCH faster than on a plane. Sometimes there's luggage scanning when you go through customs. The bus takes longer than a plane, and is often around the same price, not including luggage, and around the same level of comfort. But if you don't want to fly or drive, this is the way to do it.

[@TheNapalmFTW]

​@@becauseimafanin the US they're officially called Motor Coaches but I don't know that anyone uses that term.

[@sarkybugger5009]

I am proud to say that I contributed to its construction, in a small way. I worked there as a loco driver for a couple of years, with the hand tunnelling gangs that dug the cross-passages and piston relief ducts on the land drives. Made a few trips to the marine TBMs, delivering ring segments and grout. Quite intimidating machines, the first time you drive inside one. They're huge. The crossovers were even bigger before they put the doors in. I still have my tallies, a TML t-shirt that still fits, and my breakthrough medal. Oh, and a 5lb ammonite that I pulled off the conveyor belt, before it disappeared for another few million years. 😁 Best wages this part of the country had ever seen, which was a bonus... The disadvantage was that now that HS1 is open, people from London have moved to Folkestone in large numbers, pushing house prices through the roof.

[@gjwdavies]

My father still has his TML helmet! Not sure what happened to his wellies 😅

[@fatman3785]

The whole of Kent suffers from London proximity. Only any use if you work inn the city (i don't and don't want to)

[@jakobrebeki]

I worked on the channel tunnel and for me the best part was working in the cathedral (the crossovers in the middle). I was lucky enough to be at the break thru party as well. what a great job to be on....

[@mmckenzie9367]

Any details about the breakthrough would be appreciated.

[@MazHem]

Thank you for your hard work

[@uzijn]

Please share more about the breakthrough party.

[@jakobrebeki]

@@uzijn we were on standby to cover any electrical breakdowns as the last thing was for at the moment of truth the lights would go out. When it broke thru there was a loud cheer and lots of clapping and whistling. The no booze in the tunnel rule was broken and I had a glass of white wine. There was no food as such but I remember being given a plate with choc gatau cake and as I ate it it had a small amount of grit/sand from the workings had found its way in so crunchy cake it was. The thing I remember the most is that there was not enough toilets to supply all the extra guests and crew. Cannot remember much more then that. Such a happy day....

[@uzijn]

Wow, what a great and hilarious story. I bet that cake was still delicious, shame they didn't bring any champagne though! I hope you weren't too troubled by the lack of loos. Great once in a lifetime moment and now you have an amazing story to share. Thank you for sharing it.@@jakobrebeki

[@ZeroN1neZero]

Hi, I’m from Cincinnati, Ohio, where our railway revitalization was sabotaged and then buried like it never happened. The fact that two separate countries built an underwater railway that still functions well to this day is both thrilling and discouraging. I feel like Cincinnati could easily have a decent rail system but year after year, it just continues to decay under the ground.

[@smvwees]

I hope they run some light rail tram through there (Ohio) one day that can also run on streetlevel in rural areas. You see all these trams popup so i hope they do that one day.

[@ZeroN1neZero]

@@smvwees so we do have a tram service that operates in the downtown area and it IS completely free to use, both great things for events and stuff. I just think we need options for travel. We like to joke that I-75 is always under construction but it’s true! And with Cincinnati already having a big train industry, it just doesn’t make sense to me that we don’t have passenger rail like other cities.

[@arcan762]

that's car addiction for you

[@WiseWik]

@@arcan762 that's US for you. If some fat cat can't stuff his pockets, then it's not worth it. And that attitude has spread now sadly...

[@ZeroN1neZero]

@@WiseWik it’s probably a little of column A and a little of column B. We have one of the largest car malls in the midwest here so it wouldn’t surprise me if shithole car dealers had something to do with the “tunnels being built too small so no train UwU”. I was a teen when I heard about that and instantly smelled the bs.

[@MCP53]

Nice one Grady! I'm a Brit and I've used the Chunnel twice so far. We were relocating the whole family from Vaasa in Finland to Devon in the SW of England. That involved one car, and a big van driven by myself. The route was 'simple' enough, drive from Vaasa to Turku, a ferry from Turku to Stockholm, drive across the big bridge from Sweden to Denmark, keep driving and the Chunnel awaited. Drive onto the train, twiddle thumbs and get off in Dover - then a big drive west. The second was returning the van!

[@caeruleusvm7621]

It sounds like an interesting odyssey. Thanks for sharing.

[@JP_TaVeryMuch]

My two favourite civil engineering wonders of Europe! I hope that you're enjoying being in the "sunny" South West. As for the epic journey, well... Proper Job!

[@SoupMagoosh]

Sounds like an epic journey, my family migrated from Athens, Greece to Newcastle, England a few decades ago, it involved a ferry to Italy, a very long drive across 2 countries then another ferry across the channel. This was before the Chunnel was built so my family didn’t get the chance to use it.

[@BnORailFan]

I have traveled through the Channel Tunnel twice, first by car on the train, second as strictly a passenger. When going by car I was standing next to it waiting to start moving and said out loud when will be be going, then I looked out the small window and saw that we were already moving. That was the smoothest train ride I have ever been on. Very impressive.

[@4RILDIGITAL]

An impressively informative video, truly brings to life the sheer scale and daring of this mega project. It's astounding to comprehend the amount of engineering knowledge and expertise it took to bring the Chunnel into reality.

[@mirskym]

By the way, I bought your book and my grandchildren aged 8 - 10 love it! They think the hard hatted engineer is funny but they are really learning. A source of pleasure for me as I am a retired Electrical Engineer (Power Systems).

[@estelle8457]

are you reading it to them, or is it really accessible ? I have a teenager who is interested in engineering but not so much in reading :D

[@mirskym]

​@@estelle8457They are young so I read it to them and they look at the pictures

[@ce1834]

This project was the reaching of centuries of ambition, even today, one of the most iconic engineering marvels - you get on a high speed train city centre to centre up to 300km/h on other sections, or drive your car onto a train! A second Channel crossing would be great imo

[@vcokltfre]

The sheer number of tunnel puns in this video is incredible, 10/10

[@Hans-gb4mv]

I guess you dig those.

[@Clyde__Frog]

I found them quite boring tbh

[@JJGeneral1]

Took me a while to excavate them from the video, but once I found them, I really dug them.

[@JSMCPN]

This video sent me down the biggest... rabbit-hole ever! I'll never get... bored

[@RCAvhstape]

This is a very deep discussion.

[@tottiamus]

Excellent content as always! :) One point about the comparison with flights is that their prices are kept artificially cheap by not reflecting the huge external costs due to a lack of kerosene and CO2 taxation - predatory budget airlines are really not a great reason to doubt the merits of this awesome infrastructure project. Looking forward to the next video!

[@RCAvhstape]

Taxation is a cost, lack of taxation is not, despite all the nonsense they're teaching people nowadays.

[@RCAvhstape]

@@cmmartti Yeah sure.

[@thepedrothethethe6151]

@@RCAvhstape If your grandparents need to be hospitalized due to respiratories issues, agravated from the burning of fuel, is it a cost created by the people who burn it, to you?

[@RCAvhstape]

@@thepedrothethethe6151 Yeah, sure

[@Brian-L]

I’m heading to Europe in June. Having a childhood love of trains, I’m so looking forward to my ride in the Chunnel!

[@kozmaz87]

This is my favourite way of travelling to the continent. Especially the car shuttle service. I like that one. The whole thing is weird and wonderful and I love it. The cool thing about the pricing is that if your car is full of people it still costs 1 car to cross not 4-5 people. It is by far one of the cheapest ways to travel in some cases even with budget airlines.

[@thoughtful_criticiser]

You can now travel by high speed train from London to Amsterdam, Brussels and Paris. The tunnel did mean the end of a more amazing means of crossing the channel, the massive hovercraft that did the trip in about 20 minutes with or without your car.

[@skylined5534]

Oh man, I wish I'd got to go on one of those! Remember the really old design of hovercraft with the huge exposed props too? Really interesting!

[@ChrisHalls1]

There was also a hydrofoil, which I travelled on once in 1991. You could take your car on, and it would get you across way quicker than a ferry.

[@MeteorMark]

Those massive Hovercrafts were a feat of engineering as well! Only seen a couple when on a highschool trip to London in the 80's when we were crossing by ferry from Calais. Most impressive was in Dover where they came into port and "floated" in to "land" wit all the noise from the engines and propellers!

[@vilemeister]

@@skylined5534 Not as big, but there is still a regular scheduled passenger hovercraft service from Portsmouth to the Isle of Wight (south coast of England). I intend to go on it this summer as I've never been and have only lived an hour away all my life. There is one of these hovercraft in the museum in Gosport, not far. Doesn't work now, but its still there and you can go on it.

[@user-fj7df3ng7z]

Twenty minutes to cross by hovercraft? Are you sure? I took that trip in 1991 and I think it took somewhere between an hour and a half and two hours....

[@freebirdofreason1994]

I was 27 when i started working during construction of this tunnel, i worked underground for most of the construction. A very Dangerous job but a very memorable experience as a young lad, a dirty hot and dusty environment. I then went on to drive the trains through for Eurotunnel for many years. Now retired , the tunnel paid my mortgage, although we must remember all that lost their lives during construction, about 14 I seem to remember.

[@greentravels2850]

Great overview video; I didn't know about the "tube" bridge idea that was proposed! As a kid I remember watching the construction of the Chunnel on the news. Several years ago on my first trip out of the country I went to London, with a planned day trip to Paris. I just HAD to take the Eurostar, the thought of taking a train underneath the channel was too good to pass up. The whole trip definitely didn't disappoint. Much easier than taking a plane too; center of city to center of city with minimal lines and passing through customs before you even get on the train. I would definitely do the trip again.

[@mfaizsyahmi]

Might be a bit more hassle with customs and immigration today after Brexit.

[@shigekax]

​@@mfaizsyahmi yeah but the same extra hassle is also in airports, it's still a better experience

[@PainterVierax]

@@mfaizsyahmi TBH, Brexit doesn't really change anything for customs and immigration since UK never was part of the Schengen area in the first place.

[@Nihilimus]

My first time traveling to England I took the tunnel because I found it fascinating. You sit inside your car or stand next to your motorcycle, inside a train car and wait for half an hour or so. There's nothing to see. Still glad I did it, but the ferry feels nicer. You can stand outside on the deck and have a look at the cliffs of Dover.

[@roblonsdale8927]

I agree, the ferry is a much more pleasant experience and cheaper too

[@ProfessorPesca]

I remember being about 10 years old at school in England when the tunnel broke through. It was so exciting and to be honest even now the feeling of driving one’s car along inside a train before looking up and thinking of all the water over your head is exhilarating. Wonderful video as always Grady.

[@Pr3stag3]

Thank you for showing UK engineering some love.

[@MRrwmac]

Thank you for another very interesting AND informative video! I’m 73 and several wonderful engineering accomplishments have happened in my short lifetime. I wish I could live much longer and see us evolving in space and on earth! Hopefully reducing crime! Thanks again!

[@dascandy]

Been in the chunnel quite a few times since it opened. First in 1994 as a kid, then in the 2015-2023 timespan to go to conferences. The Eurostar is a great and comfortable train. One of the conferences was *in* Folkestone, and the passenger train only stops in London (requiring at least 2 hours of additional travel), so I brought my car along as a ticket to get off in Folkestone. The Shuttle service is pretty fast, but I will choose the Eurostar if they are otherwise equal. Shuttle has longer delays and wait times before you can board, and everybody's carrying their car onboard so boarding takes a long time.

[@Hans-gb4mv]

I always check in my car at the counter instead of carrying it on board, you waste some time at reclaim after arrival, but still, so much more convenient.

[@gordon1545]

@@Hans-gb4mv I've got a small car so I can fit it in the overhead compartment.

[@aesthetic_coconut_is_here]

@@gordon1545these comments 😭 did not expect such good humour from a “geek” video!

[@concretebadger]

Such a well-presented and informative video! Learning about the construction of the tunnel as a kid was fascinating, but I still learned a few things from this. Even today, it's such a comfortable and convenient way to travel: in recent years I've gone from my home in the north of England to Paris, Frankfurt and Vienna without needing to get on a plane. It's probably better for the environment than flying too!

[@gordon1545]

It's *vastly* better for the environment that flying, as it's on electric trains. The GB grid is pretty low carbon but the French is much lower, as it mostly comes from nuclear power. That adds up to flying having TEN TIMES the emissions per passenger km, as aviation fuel is pretty dirty and it's even worse when you inject it high into the atmosphere. Really, flights between London, Paris, Brussels and Amsterdam should be banned now. But the train needs to be cheaper too.

[@GeneralThargor]

Hi Grady. I love your videos, and can't get enough of them. You mentioned in this about the new connector being installed in the tunnel. You should do a video on the UK and Europe's plans for the electrical grid they are building. Plans include new islands, thousands of windmills and untold undersea cables to connect it all together, all in the North Sea, east of the UK and north of the Netherlands.

[@Joe-ep9jg]

In 2004 I took an overnight bus from London to Paris via a ferry. It was absolutely miserable!! A few years later I did the same trip via highspeed rail through the Chunnel. It was a quick, comfortable trip. That being said, seeing the white cliffs of Dover from a ship is pretty awe inspiring!

[@user-fj7df3ng7z]

I took the conventional ferry across the Channel on a beautiful sunny August day in 1983 in the middle of the day and it was absolutely fine. The Channel was as smooth as glass. I'd been worried about nausea/seasickness and had dramamine but didn't have a moment of difficulty. I wish I could remember the duration of the crossing - and the endpoints for the ferry - but I *think* it was about 3 hours. The next time I crossed the Channel was in 1991, this time by hover ferry. Again, I don't remember the crossing time but I *think* it was about 90 minutes. This was also a totally trouble-free crossing. I would happily take either trip again. I haven't taken the Eurostar yet so maybe I'd like that even better :-)

[@TheJf89]

Thanks Grady! Literally learn or understand something better everytime I watch one of your videos

[@FrankstaPasta]

I've travelled on the channel tunnel many times in my life. Most recently I boarded it on my motorcycle! I got on my bike at my house in the south of England and rode 800 miles to the Mosel Valley in Germany (not in one day). The tunnel was by far the easiest part of the trip. Its definitely hotter in there than you'd think! Nice to be able to take your own vehicle and the ride is smooth so you dont have to lash the bike down. Theres nowhere to sit down if youre on a bike though, other than the rail car floor 😂

[@piraterubberduck6056]

I have crossed through the tunnel, on a ferry and by plane to France. The tunnel is the most comfortable, and is often the most convenient if your destination or origin is near the service.

[@JulianShagworthy]

Ferries are the better choice if you're travelling from the South/Southwest of England to the North/Northwest of France. To travel from Portsmouth to Ouistreham, for instance, takes 5-6 hrs on the ferry versus a 7 hr + drive via the tunnel. Plymouth to Roscoff is a 13 hr, 735 mile drive via the tunnel, or a 9 hr, 120 mile ferry crossing. Depends on lots of things including preference, cost of fuel and so on!

[@HappyDaysNI]

Hi Grady. Greeting from Ireland. Travelled from Paris to London a few years ago via the tunnel. Looked forward to the experience immensely but it was a bit of a disappointment. No announcement or anything. The scenery suddenly disappeared and about 10 minutes later it reappeared! I suppose in 30 years, most people who were going for the experience had already done so! Still, I enjoyed it! Hope you get to some day too. Love the channel, items in plain sight still amaze me!

[@scallywag1716]

I rode it in 2000 and honestly it was pretty epic. For someone that’s been on only a few trains and most of those going about 60 mph max it was a very different experience. I wonder what it would feel like to me now…very interesting!

[@alexturlais8558]

I've gone through the tunnel about 60 times in my life, and it's incredibly cool and convenient. A marvel of engineering and even if it isn't as profitable as expected, its a source of national pride and despite the low cost of flying, has completely disrupted the london-paris travel route.

[@wraithcadmus]

3:09 - Fun fact/correction: Like our cars, UK trains run on the left. You'd think this would cause an issue with France, but they run on the left too because their railways started later and used a lot of British expertise. To stan the National Railway Museum in York again, they have one of the Channel Tunnel construction locomotives as an exhibit and yeah the thing absolutely looks like it spent several years working hard in a salty environment.

[@squeaksvids5886]

Not all of France’s trains run on the left. Parts of SNCF in eastern France run on the right, a legacy of being once part of Germany.

[@Baxtexx]

Would love to see a similar video about the Öresund bridge between Sweden and Denmark and the Malmö City Tunnel.

[@thany3]

I suppose the Seikan Tunnel, connecting Tohoku and Hokkaido in Japan, must've faced similar challenges. I'm not sure how long it is, but it's definitely one of the longest undersea tunnels.

[@five-toedslothbear4051]

Seikan is the longest undersea tunnel by overall length, while the Channel Tunnel is the tunnel with the longest undersea segment. I definitely want to ride the Seikan tunnel on the Shinkansen.

[@waka630]

I am so glad to see some people mention about Seikan Tunnel, built with enormous effort, challenge, and sacrifice from my hometown. My grandfather also joined in the construction and a memorial rock (it is from real undersea-underground!) is displayed in my parents' home.

[@thany3]

@@five-toedslothbear4051 I've done so only once yet, and they do make it into a bit of a happening. They're clearly very proud of the tunnel. Actually I have been through the tunnel more than once, but by normal trains before the Hokkaido Shinkansen was realised. Back then the same Shinkansen only went as far as Shin-Aomori and you would have to change there. Now that the Shinkansen goes through it, its terminal is Shin-Hakodate-Hokuto, which sadly isn't really almost anyone's destination. I'm looking forward to when they extend the line all the way to Sapporo 😍

[@TheClunkingFist]

When I lived in London, I loved taking Eurostar to Paris for a weekend, including once to watch a game of rugby at Stade de France. Magic. This was pre-HS1 days, so from Waterloo through towns and little villages in the south of England.

[@aidanf2610]

France: let’s just pump the spoils into this area over here England: *_more England_*

[@aidanf2610]

aye this was funny asf bro 👍

[@mattsoutherden]

I've been through the tunnel a number of ways. The simple crossing from Folkestone to Calais is good, but where it really shines is when it's part of the wider rail network. The simplicity of city centre to city centre travel with room to move and no painful airport parking and terminal experience is great. Sadly after Brexit and Covid the number of destinations available direct from London has been cut to only Brussels, Amsterdam, and Paris. It used to be possible to get a direct 'Snow Train' to the French Alps during the ski season. That was a fantastic way to go skiing when we had a tiny baby. Obviously it's still possible to cross the channel and then change trains, but that loses some of the appeal when you're traveling with luggage and small kids.

[@martinstent5339]

Just want to mention here, that by the time you have driven across half Europe, it's really nice to relax on the boat, take a meal and maybe a nap. Watching the white cliffs of Dover come over the horizon is also a lovely sight! I've taken the tunnel, but the boat ride is just a pleasant break in a long and hard journey.

[@jonathanleach3914]

Used the tunnel many times. My favourite is getting the train from London to Paris or Brussels. The other “fun fact” is that at St Pancras station in London is the country’s longest champagne bar as it runs alongside where the trains are. Thanks for your films. Always interesting and informative.

[@tayloreverard2039]

This particular video is a testament to the broad accessibility of your channel, the channel tunnel is something I've thought was cool from a historical/geopolitical perspective, but never thought to look into the bricks and mortar of it. What a wonderful way to resurrect a random curiosity

[@marsgal42]

I've been through the Channel Tunnel several times. You have no idea how far underground you are, nor do you have any feeling that you're under water. The train just whirrs along for a while then pops up at the other end. The longest tunnel on the London Underground, BTW, is 28 km. Northern Line, East Finchley to Morden via Bank. In its day it was the longest railway tunnel in the world.

[@Tiger351]

Great video on the subject, it was big news worldwide at the time and I was fascinated by the project having just started high school. It's a little ironic that the previous record holder for longest undersea tunnel (Japan's Seikan tunnel) wrapped up the year the Chunnel project started, if you haven't previously covered that on the channel I'm going to suggest making a video on it in future.

[@BilgeDweller]

One of the engineers that I worked with at MEMCO Barge Line had been involved with the Chunnel, and he maintained that it was far and away the most interesting thing that he had ever done.

[@r25limousine]

That thing is always busy and so much faster. It has been a massive success

[@BirdbrainEngineer]

Hey! A video idea that has to do with electrical grids, that would be nice if you covered... Soon (next year) the Baltic states are going to disconnect from the Russian electric grid, and connect up to the European electric grid. This feat is meant to be achieved with no disruption to industries and everyday life - a task seemingly simple, but under the surface, has some nuance to it. Maybe there's enough substance for a video!

[@donaldneill4419]

Back in the summer of 2001, I took my mom from Brussels to London on the Eurostar. It was positively amazing and yet, at the same time, completely unremarkable, because millions of other people have done it. Any way you look at it, the Chunnel was an epic feat of engineering - though as an historian, I can't help recall what Lord St. Vincent once said about the risk of invasion from Napoleon's fleet of flat-bottomed boats: "I do not say they cannot come; I only say that they cannot come by sea." Well, now they don't have to.

[@adrien5834]

It's rumored that the British government planted a nuke somewhere at the British end of the Chunnel, just in case.

[@emmajacobs5575]

@@adrien5834when you think about it, that sounds more and more like an urban myth - why would they risk contamination by fallout at the British end rather than planting it at the French end? In fact why risk contamination at all instead of just using conventional explosives? And there are so many people working on the tunnel from both sides that it’d be impossible to keep something like that a secret and when it inevitably got out, would cause a huge diplomatic problem between the two countries.

[@adrien5834]

@@emmajacobs5575 Oh, I'm not insisting that it's true, it's just a rumor. As for not planting it at the French end of the tunnel well it makes sense if you want to make sure that you remain in control of your booby trap.

[@Eagle3302PL]

@@adrien5834 Using any explosives makes no sense at all, all you have to do to defend the tunnel is set up a few gunner positions and concrete barriers at the entrance, no sane military leader would try using the tunnel to invade if they can just send a bunch of boats.

[@adrien5834]

@@Eagle3302PL Hmm. Okay?

[@KyouRein]

I did a bit of research about the chunnel when it was announced that the HRBT here in Virginia USA was getting an upgrade. We now have several bits of the equipment used then and some upgrades for that project. It is absolutely hell traffic with the construction, but it was bad before. I tried to understand the science and math on my own but this cleared most of it up, thank you

[@SecretSquirrelFun]

Absolutely fascinating, thank you for this. I was blown away that they were only out by around 2 feet 😳That’s impressive isn’t it. This makes our 2.3 km Sydney Harbour Tunnel seem tiny in comparison 😳 The part about tunnel digging that I hadn’t considered until relatively recently was what they did to get rid of and remove all of the soil and debris. Finding out about the different ways that this is managed during big tunnel projects was fascinating. It becomes a whole project of its own that involves transferring the spoil in an environmentally responsible manner, keeping dust levels down with water spraying as well as managing any residential concerns when relevant. And then there is all of the vehicles required, both inside and then outside the tunnel to transport the spoil away. The infrastructure necessary to keep both workers and equipment on site and ultimately where the spoil goes etcetera Anyway, thanks for sharing this video with me. Much appreciated as always. Take care. 🙂🐿🌈❤️ [sydney australia]

[@mrsdiss]

now i'd like to see a comparison between the chunnel and the gotthard base tunnel. both are huge engineering projects, they face many similar problems, but also some very different challenges

[@zachbrenner9959]

It would be awesome if you did a breakdown of the Chesapeake Bay Bridge Tunnel and the ongoing project to add more tunnels to it

[@DrummingDrummer15]

I cross it every day and traffic is miserable.

[@djtaylorutube]

I remember watching the breakthrough on TV when i was much younger. Finally got to take the car through for the first time last year. Loved it! Been again a couple of months ago and already booked up for another trip in May.

[@AndrewMann205]

Your channel is one of the best highlighting engineering projects. Thank you and keep up the good work.

[@shaider1982]

The nice thing about this compared to ferries or airlines is that it can be powered by power sources apart from fossil fuels. Especially considering how France has lots of nuclear power plants.

[@RadekSimko]

As a Londoner, I can't help but notice that the station shown in the time lapse at 16:42 is King's Cross which may be interesting for Harry Potter fans who come there to take pictures of the platform 9 3/4 but all trains from there would only take you to UK destinations, mostly north (i.e. you cannot get to France from there). It is the other station nearby, St. Pancras [International] which has southern connections to Folkestone, France and mainland Europe. Most people refer to both stations together as "King's Cross & St. Pancras" but they are two separate buildings with entirely different set of platforms, barriers, (lack of) border control etc. (sic connected through some long pedestrian tunnels)

[@TheDarrenJones]

I've used the channel tunnel many times to go from the UK to France, mostly on family holidays, with 6 of us in my van. It's cheaper than flying, and lower on emissions. Yes, it's a bit slower (particularly as I have to drive 180 miles to get to the tunnel in the first place, but live in a town where I could get straight on a ferry), but if you want to take a lot with you, then it's difficult to beat. It's an amazing thing getting in the train in the UK, and being in France half an hour later, and just driving off into a foreign country. Ferries are generally more expensive than the tunnel, and while we did it once, it was an underwhelming experience. Great look into the project, quite a bit I didn't know about it in there. Thanks!

[@wonderfultigger6620]

Great video as always, brady. Your enthusiasm is shared by many that love big projects that make our world just a little more connected.

[@joshlikescola]

This is less of an issue with the Chunnel itself, but I think the reason it has been relatively poorly utilised is that the UK hasn't really tried to expand the reach of service much. St Pancras is a huge bottleneck now, not because of the platforms, but because it simply doesn't have the amount of space an airport does to process passengers. Track access charges are very high for HS1 and limited effort has been made to expand service northward, or try to connect up HS1 with our other mainlines and what is left of HS2. I'm glad you mentioned this in your video, that frustratingly, Eurostar is not an economical option for many outside of London. You are paying full price for a ticket into London and because of your more limited journey times, are unable to take advantage of off peak fares on Eurostar, which is surprisingly expensive!

[@colinnich]

I was in London with the family for a week (4 of us) and fancied going to France for the day. We were looking at about £900 to go by train, or £80 to take the car from Folkestone. I'd say the passenger train is just a little overpriced, like every other train in the UK.

[@seanbrockest3888]

30 years since the opening? NO way. I remember when that happened... that means I'm ..... Old....

[@BenPass12]

Happens to the best of us

[@ericshelley1463]

Another awesome video Grady! I remember hearing about the Chunnel being built as a kid and was totally fascinated by the entire project!

[@einstein0808]

Wow. The complexity. Thank you!

[@Kostchei]

Thanks for all the handy illustrations! I have to question one point though: The numbers at 13:00 seem highly unrealistic to me, some quick googling later I found a figure quoting a factory worker at one of these cooling plants. They gave 7°C or 44°F, which I find way more believable for one of Europes biggest cooling system ^^

[@jmonsted]

Yeah, i was just typing this as i glanced down and saw your comment. Good video anyway. Also, i just got the "engineering in plain sight" book and enjoying it :)

[@PracticalEngineeringChannel]

Sorry for the confusion. That could have been worded better. The refrigerant temperature is indeed much cooler than the numbers quoted, but the maximum design temperature for the tunnel itself was 35C, 95F.

[@rvrrunner]

Several months ago we took the train between Paris and London and going through the tunnel was one of the high points. Even more after watching this video. Thank You

[@JohnADoe-pg1qk]

Strictly speaking, it was the lowest point. 🤔😁

[@beeble2003]

Nice video! Please come visit, one day! A couple of minor corrections. 1. Folkestone sounds like "folk" and "yolk", not like James Polk. 2. It was possible to take the train from London to Paris from the day the tunnel opened for business. But until High Speed 1 opened, the trains were sharing track with London's commuter rail network, so were puttering along at under 100mph. HS1 allows them to run at 300km/h (186mph). 3. These days, the ferries exist primarily for freight, though they do still carry cars and passengers. There are significant restrictions on taking hazardous material through the tunnel.

[@Vaultdorr]

I've always wondered how they navigate when digging tunnels. I'd love a detailed video on how it works.

[@arwynbrock7591]

I actually prefer taking the ferry to europe instead of the train, despite being a big rail fan. I'm over 3 hours of driving away from the south coast, and having an hour and a half on the boat to get food, get some fresh air and even just to take in the coastline before you arrive is a really nice pause, and allows your brain to reset before continuing your drive on the "wrong" side of the road. Plus it's about half the cost of the train, which is nice.

[@banksarenotyourfriends]

From the North of England, the high cost of rail tickets in the UK makes the Channel Tunnel fairly expensive to get to - taking the ferry takes much longer, but the extra time is spent relaxing in comfort, and not in traffic or on a crowded train.

[@cjplay2]

Going through this tunnel is on my bucket list... Thank you for the video!

[@lemster101]

This is one of those projects that deserve to exist even if they don't make absolute financial sense, especially in the short term. It has had a profound impact on how the UK and Europe developed.

[@jensschroder8214]

There is also a high-voltage DC line in the Euro Tunnel. This connects the high-voltage AC network on the mainland with the high-voltage AC network in England. It allows electricity to be transmitted in both directions, as needed. In continental Europe there is the connected power grid and in England, Wales and Scotland there is the English grid. Both networks sell and buy electricity from each other on the European electricity exchange. This leads to a high level of reliability because many power plants are networked.

[@dewiz9596]

Wow! You really “killed it” with this one, Grady. By the way, I’ve loaned your book to a friend of mine. . . an engineer. I’m awaiting feedback! And I’ve shared this video with him, too.

[@alexkotenko1737]

I've travelled the Chunnel many times, living in London and spending summer vacation at the French Mediterranean coast. I love driving and car trips, so for me it's always a drive from London down South to the sea. We took a ferry once or twice, but then realised the benefits of the Chunnel and not looked back. Price-wise they are comparable, especially if you book Chunnel well in advance as I usually do, and time-wise tunnel is much better. Euroshuttle (FolkestoneCalais car-ferrying train service) takes about 30 min vs 90 min of a ferry sail, and loading/unloading cycle is much faster on the Chunnel train as well, so overall arrival-departure cycle is 60-90 minutes total on a train vs 120-180 min on a ferry. This makes a difference between getting from London down to Medi within one day, vs having to make a stopover on the way.

[@williamthethespian]

Your use of subtly is wonderful and your channel is amazing. Thank you for both.

[@Twikkilol]

Cool! Also, we are building a tunnel from Denmark to Germany, can you also have a look at that? I think that will be awesome too!

[@--Paws--]

11:30 Does the piston-effect also happen in an elevator shaft or any similar tunnel like structure?

[@scbond]

Not really in elevator shafts as they aren’t travelling fast enough and for long enough distances to noticeably generate enough air pressure. In other tunnels with trains though it happens.

[@--Paws--]

@@scbond That's true, elevators are slower. Thanks.

[@ToTiredForMore]

THIS WAS GREAT! YOU SHOULD DO A VIDEO ON "THE BIG DIG" OF BOSTON. love the way this relates to what may be a video on that.

[@phildevan]

Thank you for another fascinating and excellent (as always) dive into engineering, Grady!

[@apveening]

The one thing I really regret about this tunnel is that it killed off the hovercraft service across the Channel.

[@gbcb8853]

⁠@@ithecasticAnd the NOISE unfortunately. Took it across in 1982, never wanted to do it again. Eurostar completely different.

[@apveening]

@@ithecastic I agree with most, but that oil shock had worn off by the time the tunnel opened and the hovercraft were withdrawn from service.

[@murk1e]

Hovercraft are still in service at the Isle of Wight (not the same as a channel crossing, I know) I took a channel hovercraft back in the day…. Rough crossing. Went over every wave! (Not through, like a ferry)

[@JevonWright]

I've travelled through the tunnel four times and it is by far one of my favourite transport modes of all time!!!

[@To.Die.Alone.UnLoved.]

You know! It’s soo nice seeing Less Nessman of WKRP in Cincinnati still working after all these years! Thanks Less! 👍 great report

[@Gregdotgreg]

Or as we say in the UK 'The Channel Tunnel'. That's what it's called here

[@samwalker2367]

Look at the title

[@Gregdotgreg]

@@samwalker2367 listen to the intro

[@sparqqling]

You have to give to Brits and the Frenchies, this tunnel and the Concorde.

[@startide]

We hate each other but sometimes the stars align and we can do great things together :D

[@Eagle3302PL]

@@startide Yeas, but it's a different type of hate, it's not like e.g. the sort of hate that some Asian or African countries share. It's more of a playful brotherly hate, like some brothers can't stand each other but they will show up when the other is in need.

[@startide]

@@Eagle3302PL very true ! Cheers

[@roryfiler214]

A very enjoyable edition, thank you for producing it!

[@flagger2020]

Great video, my father who sadly passed 2022 would have loved it, and im sure probably offered up lots of additional extra details. One of the topics you touched on was a real worry for him as he was a tbm driver. In previous surveys of the channel they did not originally fill in with concrete after taking core samples, so those holes would slowly silt up. If they had ever hit one of those it would have cost them a tbm or three, but they had very beefy emergency pumps to prevent total losses. After the job and then the jubilee line extension, he eventually worked for euroscan, so the tunnel was really a major part of his life.

[@jeremiahreilly9739]

Great presentation Brady. I'd quibble a bit with your offhand comments on the benefits of a projects. Benefits are very hard to value and measure. How do you include passenger satisfaction or carbon avoidance or cost-of-stress-flying a discount airline. Personally I love taking the Eurostar from London to my home in Switzerland. I stop for a 3 hour lunch in Paris. Now, that's a real pleasure.

[@user-tn1vc1xz5d]

The earlier tunnel planned in the 1800s was a similar size and was to use the same rock layer. The designer used to dive to the channel bed from a boat to collect rocks (he held his breath, weighed down with bags of stones, got his samples, released the ballast then came up). His geological map was very good. Today, the French end is round, the UK end is square due to a cut n cover box section through a nature reserve. Large loops of track on each side allow for the direction change and ensure equal distance of L and R turns to balance wheel flange wear on the rolling stock. Train cabs have limited side vision to reduce "segment flicker".

[@andriisnihyr6497]

Thank you for the video! It is amazing that they were able to dig a tunnel from both sides and meet within 2ft of each other!

[@kiwihigh]

In NZ we have a train tunnel in our alps that goes from Arthurs Pass to Otira that was built in 1908...It is 8.5km long, basically hand built/dug drops and winds down 300ish mtrs, was also dug from both ends and meet in the middle with similar accuracy.. Always found it massively impressive and even more so now!

[@AndrewJonkers]

It is still being used by tens of thousands of people and heaps of freight per year, so the term white elephant is a bit much. Then again, I am an engineer. Accountants be damned - some things are more interesting than money.

[@benjaminschacht92]

I had to look up definition of white elephant, never heard that before -.-

[@SkeledroMan]

I thought the seikan tunnel in japan was still bigger than the channel tunnel, and underwater.

[@milanreyniers2399]

It is by 3 km

[@christhompson2006]

The underwater section is roughly half the length of the channel tunnel.

[@ce1834]

the Channel Tunnel has a longer undersea section - 23.5 miles in Channel Tunnel vs 14.3 miles in the Seikan Tunnel

[@danial1635]

Kudos and thank you for the very helpful and descriptive visuals. They were extremely helpful in understanding how the TBMs worked.

[@liveinthesunshine3018]

great video. We live about 20 mins from the tunnel (UK). We use it all the time. It is so convenient and an efficient way of crossing the channel. After it opened we used to regularly pop over to France for dinner after work on a Friday eve with the car and come back later that evening. We used to get a return crossing for £1 then! Now it's more like several hundred pounds. The ferry is cheaper but we still use the tunnel. All these years on and the engineering is still impressive.