Speaker 1: Brought to you by the all New Toyota Corolla. Welcome
Speaker 1: to you stuff you should know from House Stuff Works
Speaker 1: dot com. Hey, and welcome to the podcast. I'm Josh Clark.
Speaker 1: There's Charles W. Bryant. Noel is with us again. That's right. Really,
Speaker 1: it's just been a very short period of time since
Speaker 1: he was last with us. Well, who knows, we might
Speaker 1: release these weeks apart just to throw people, you know,
Speaker 1: it's possible. How you doing fine? How are you? I'm
Speaker 1: good man, I'm I'm great, I'm right. A tunnel through
Speaker 1: this show and get all up out of him. That's
Speaker 1: pretty lame. It was okay, Um, it worked though, because
Speaker 1: what we're talking about has to do with tunnels. Yes,
Speaker 1: I don't know if you caught that. Yeah, we covered
Speaker 1: a little bit of this in the Subways podcast. Yeah,
Speaker 1: cutt and cover, cut and cover, But this is this
Speaker 1: goes deep undercutting covering. You gotta stop. I don't know. Yeah,
Speaker 1: we're talking about underwater tunnel specifically. That's right, which, by
Speaker 1: the way, we should probably say for those of you
Speaker 1: who are into semantics, um, the word tunnel is applied
Speaker 1: only to something that is bored entirely underground. Yes, if
Speaker 1: if you say, like we talked about with cut and
Speaker 1: cover in subways, if you dig out a trench, put
Speaker 1: in your tunnel and then backfill over your tunnel, what
Speaker 1: you've created is a conduit. Yeah. And if you if
Speaker 1: you correct people when they talk about this kind of thing,
Speaker 1: you're so obnoxious or you're an engineer or sea. But
Speaker 1: engineers don't even do that because they still want to
Speaker 1: be liked, you know, they don't want to be that guy. Um. Yeah,
Speaker 1: So we're talking about how and I think a lot
Speaker 1: of people wonder how did you managed to get a
Speaker 1: tunnel under the water. We're gonna tell you it's really
Speaker 1: not that hard and there's a few ways. Yeah, I
Speaker 1: don't know if saying it's not that hard is correct. Well,
Speaker 1: not that um complicated in a engineering sense. Again, No,
Speaker 1: I think none of these Like I was like, what
Speaker 1: they bore a tunnel under a river? Right? But just
Speaker 1: the this is the the overview. I mean, you can't
Speaker 1: read this article ago building underwater railway tunnel? Is that
Speaker 1: what you thought I was saying. No, No No, I'm just
Speaker 1: saying like there's so much more to like just the details. Yeah,
Speaker 1: I mean, but you weren't saying that there's particle physics
Speaker 1: and there's digging a big hole under a river. You
Speaker 1: know what I'm saying, Man, we're going to hear from
Speaker 1: some angry civil engineer. No. I think it's great. I
Speaker 1: think it's modern, modern marvel is what it is. It is. Yeah,
Speaker 1: so chuck, Yes, it's not necessarily modern, and it's no.
Speaker 1: People have been digging under rivers um since the Babylonians. Yeah,
Speaker 1: I was quite surprised by this. They managed to build
Speaker 1: a three thousand foot bricklined, art supported tunnel twelve by
Speaker 1: fifteen feet under well, they diverted the Euphrates River and
Speaker 1: it was a pedestrian passageway. That's crazy, right, This is BC.
Speaker 1: And I think they diverted it temporarily. Well yeah, sure,
Speaker 1: but even still it's still a tunnel. And they still
Speaker 1: did this several thousand years ago, and they diverted a
Speaker 1: river which is in President's own. I'm impressed with them.
Speaker 1: I'm glad to hear you are too. Um. Over the years,
Speaker 1: people kind of I imagine, built and failed spectacularly and
Speaker 1: trying to build underwater. Um. It wasn't until the nineteenth
Speaker 1: century that people really kind of started to advance by
Speaker 1: leaps and bounds over say the Babylonian methods to come
Speaker 1: up with some techniques that are still in use today. Yeah,
Speaker 1: as far as underwater goes, I mean, they were tunneling
Speaker 1: all during the eighteenth and nineteen centuries. And in fact,
Speaker 1: the word undermine I thought it was fairly interesting. It
Speaker 1: came from the fact that there were miners who dug
Speaker 1: undercastle walls to collapse them. That's a pretty good idea. Yeah,
Speaker 1: it's a very good idea. And I don't think we
Speaker 1: covered that in our Castle podcast either. No, I wish
Speaker 1: we had. Yeah, that would have been complete. That that
Speaker 1: episode is incomplete. But like you said, it was eighteen
Speaker 1: hundreds when we finally said, hey, let's try this underwater
Speaker 1: thing again because we think we can do it now. Yeah,
Speaker 1: and they kind of had it licked. And again, like
Speaker 1: I said, some of the techniques that they came up
Speaker 1: with at this time are still in use today. Yeah.
Speaker 1: I got a question for you, though, If it's dangerous
Speaker 1: and it's uh pricey, why do you tunnel at all?
Speaker 1: Why not just build bridges? That's a fantastic question, and
Speaker 1: I happen to have some answers. Okay, all right, I
Speaker 1: still thinking about this. You build a bridge, it makes sense,
Speaker 1: it's beautiful bridge works. We know how to build bridges,
Speaker 1: We've been doing it forever. But what if you have
Speaker 1: a heavily trafficked shipping lane with ships that are taller
Speaker 1: than your bridge. You can build a drawbridge, but it's
Speaker 1: gonna be up and down, up and now and up
Speaker 1: and down all day. And don't fool yourself. A drawbridge
Speaker 1: is pretty expensive too. That's one all right. Uh. If
Speaker 1: you are um an enemy of the United States, your
Speaker 1: bridge could be a target from air strikes. Yeah, that's
Speaker 1: a problem for you if you I mean, if you
Speaker 1: want to build it again afterwards, it could be struck
Speaker 1: down again and then again. You want your bridges to
Speaker 1: remain intact. Yes, I'm gonna argue for tunnels here though,
Speaker 1: my friend and say that they will stand tides very
Speaker 1: well and currents and storms. It's not out in the
Speaker 1: open like a bridge is. Uh. You can go greater
Speaker 1: distances with the tunnel, and you can carry like almost
Speaker 1: virtually unlimited amounts of weight. So score one for tunnel
Speaker 1: and chuck yeah, because with the bridge you have to
Speaker 1: worry about it collapsing with the tunnel. It's like, no,
Speaker 1: you're probably pretty firm against some sort of bedrock or
Speaker 1: seabed or something like that. You're you're you can put
Speaker 1: as many trucks as you want on and it's not
Speaker 1: gonna break. Yeah, I guess we'd call seismic activity a draw.
Speaker 1: You have you ever seen? Why? Not good for either
Speaker 1: one the bridges? Yeah, that is nuts. Is that in
Speaker 1: Seattle or Washington? I don't know, man, but that's you
Speaker 1: look at that and think, how does that move like
Speaker 1: that without just completely breaking apart? It does pretty scary. So, um,
Speaker 1: we're going to call that a draw though, because earthquakes
Speaker 1: are not good for either. Um. Well, cost you said
Speaker 1: that the bridges are costly. Well, bridges are get costly
Speaker 1: or the bigger they are, whereas tunnels get cheaper the
Speaker 1: bigger they are. Yeah, the length. With the tunnel, it
Speaker 1: it starts, the cost starts to drop as it gets
Speaker 1: longer and longer. Not so with the bridge. So why
Speaker 1: then would city planners still use tunneling as a last
Speaker 1: uh sort of a last resort? I guess because they
Speaker 1: like bridges more. Okay, all right, so that wash and
Speaker 1: seen we were play acting. It's not very well either No,
Speaker 1: I thought it was pretty good. Oh, I thought was okay. So, uh,
Speaker 1: let's talk about some of the tunnels they've got going
Speaker 1: on these days that are pretty remarkable. Um, there's one
Speaker 1: that actually connects two islands in Japan. Um. It's called
Speaker 1: the Well, you're the resident Japanese expert, have you pronounced that?
Speaker 1: The Icon Tunnel, the Cicon Tunnel, And that is the
Speaker 1: one of those two holds the record for the longest
Speaker 1: and deepest underwater rail tunnel. Um. And they did that
Speaker 1: in the nineteen fifties after a typhoon sank some ferry
Speaker 1: boats and the cigar us straight and killed like over
Speaker 1: fo people. They said, you know what, maybe we should
Speaker 1: go underwater with this operation, and they did so. And
Speaker 1: it connects Hanshoe and Hokkaido, and Hokkaido is known for
Speaker 1: its uh sub factories. And you even have a tipit
Speaker 1: for me the Simpsons tidbit. Oh was that from the
Speaker 1: Mr Sparkle episode man one of the best ever. So
Speaker 1: in they completed the Icon Sikan Tunnel. Yeah, I'm gonna
Speaker 1: go with Sikan okay um and it stretches thirty three
Speaker 1: and a half miles. Yeah, the whole tunnel does. Yeah,
Speaker 1: that's impressive. It is, but then, um, only fourteen and
Speaker 1: a half miles of it, only fourteen and a half
Speaker 1: miles of it are under water. Yeah, but it goes
Speaker 1: close to eight hundred feet deep, which is that's sort
Speaker 1: of the remarkable part. That's a long way down. Yeah.
Speaker 1: You have to pop your ears when you're on that train. Oh,
Speaker 1: I'm sure. The Chunnel, which we were laughing about before
Speaker 1: we hit record. Just the name, and we should say
Speaker 1: it's called the tunnel because it's actually the Channel Tunnel.
Speaker 1: It goes under the English Channel to connect the UK
Speaker 1: in France. Yes, and that was finished in the mid
Speaker 1: nineties and uh, twenty four of its thirty one miles
Speaker 1: or underwater, but it only goes about two six ft down. Yes. Yeah,
Speaker 1: it's so funny to use words like only with stuff
Speaker 1: like this or just yea yeah. Um. And then the
Speaker 1: newest member to the underwater tunnel family is the Marmaray
Speaker 1: Tunnel that in Istanbul that connects the Asian portion of
Speaker 1: Istanbul and the European portion of Istanbul, which means it's
Speaker 1: the only underwater tunnel or the first to connect two continents.
Speaker 1: That's right, And The name comes from d c. Of
Speaker 1: Marmara and the word ray which is Turkish for rail,
Speaker 1: because it is another rail tunnel, meaning train. And uh,
Speaker 1: it's pretty cool when they were when they started digging it,
Speaker 1: this thing, this project went slow as molasses, not just
Speaker 1: because a construction, but because they came upon the port
Speaker 1: of Theodosius. Theodosius I think, is that right? Sounds good
Speaker 1: to me. So it was um it was a port
Speaker 1: in Istanbul. Back then it was constantinople Um for that
Speaker 1: was the busiest port in the world for about a
Speaker 1: thousand years, and it was lost and they came upon
Speaker 1: it while digging this tunnel, and the archaeologists were like, okay, stop, stop, stop, turn. Yeah,
Speaker 1: they found forty artifacts from this. They didn't turn, they
Speaker 1: went through it, but they documented everything and grabbed it
Speaker 1: for the museum. Well, if it hadn't been for the tunnel,
Speaker 1: maybe they would have never found that stuff, you know. Uh.
Speaker 1: So that was an immersion tunnel and it was the
Speaker 1: longest and deepest immersion tunnel ever built. Immersing tunnels are
Speaker 1: my favorite. Yeah, that's the one that I didn't think
Speaker 1: was super complicated. I saw a couple of videos and
Speaker 1: I'm telling you it is. There's a lot to it,
Speaker 1: just the pontoons alone or yeah, but it's like the
Speaker 1: kind of thing you can replicate in your bathtub, That's
Speaker 1: what I mean. But uh so we're gonna get into
Speaker 1: what that all means, because, um, there are quite a
Speaker 1: few ways to build tunnels and three. Yeah, and there
Speaker 1: wells three and use. I bet there's other dudes out
Speaker 1: there trying to figure new stuff out. Um, but one
Speaker 1: of the oldest that is still in use. It's called
Speaker 1: a tunneling shield thanks to a remarkable, remarkable dude, a
Speaker 1: Frenchman named Mark Isombard Brunel, who was eventually knighted for
Speaker 1: his work as inventing the tunnel shield. Understandably, so yeah,
Speaker 1: pretty amazing. He got the idea from watching a shipworm,
Speaker 1: which is like a naked clam because these little shells
Speaker 1: on one end. It's basically yah, it's like the termite
Speaker 1: of the sea is what they call it. Because this
Speaker 1: thing bores into docks and boats and basically tunnels into
Speaker 1: wood and uh leaves saw dust in his wake. And
Speaker 1: this guy saw this things like, hey, that's a pretty
Speaker 1: good idea. I think we'll make a tunneling feel exactly. Yeah,
Speaker 1: So he came up with the Brunell shield, which is
Speaker 1: actually rectangular, but the best way to think of what
Speaker 1: a modern tunneling shield looks like. Um, there's a description
Speaker 1: given in this article that makes sense if you add
Speaker 1: one extra sentence. You take a coffee can. Imagine a
Speaker 1: coffee can't without its lid, and the bottom part of
Speaker 1: the coffee can is pointed somewhat with some holes in it,
Speaker 1: And when you dig it into the ground and then
Speaker 1: turn it on its side to bore horizontally, what you
Speaker 1: have is something like a tunneling shield. So at the
Speaker 1: front end, what part did they miss? They're going straight
Speaker 1: down and it just completely confused me, the fact that
Speaker 1: it wasn't going to the side. Oh, I couldn't right
Speaker 1: at my head around until I finally was like, oh,
Speaker 1: I see what they're saying, So that that coffee can't
Speaker 1: imagine it jammed horizontally underground. Yeah, let's go in and
Speaker 1: explore it. Right in the front, there's holes and you
Speaker 1: have different kind of compartments where people stand there called
Speaker 1: muckers and they dig out the dirt in front of them, right. Yeah,
Speaker 1: And in Brunel's case. Um, they were cast iron shutters,
Speaker 1: and they would just open these shutters one at a
Speaker 1: time and just dig a few inches out. And back
Speaker 1: then they used screwjacks, but now they use hydraulics and
Speaker 1: just inch inch away forward a little by little, little
Speaker 1: by little, and the reinforcing them building the sides as
Speaker 1: you go right, And that coffee can in the meantime
Speaker 1: is holding that tunnel shape right, because it's the exact
Speaker 1: shape of the tunnel shield. While the guys in front
Speaker 1: are digging, the coffee can is giving them all support.
Speaker 1: And then right behind it are mac and steel workers
Speaker 1: who are reinforcing the tunnel. And then the the reinforced,
Speaker 1: finished concrete tunnel provides the stability for those hydraulic checks
Speaker 1: that slowly and little by a little inch the whole
Speaker 1: thing forward. Yeah, I mean, it's the It's like every tunnel,
Speaker 1: although actually the emergent tones aren't. But when you're digging
Speaker 1: a tunnel, it goes back to the Babylonians. You dig,
Speaker 1: support advance, dig support advance, just like Charles Bronson in
Speaker 1: The Great Escape? Oh yeah, was that his mantra? No,
Speaker 1: this was just I'm gonna go tunnel in this tunnel
Speaker 1: and build the frame. You're doing a good Bronson. Well
Speaker 1: it's sort of Bronson, but it's also sort that the
Speaker 1: guy from The Simpsons who was based on Bronson Pankas area.
Speaker 1: Is that who does that? Sure? Okay, sure, yeah, I
Speaker 1: don't know that for sure, but is it? Okay? Um,
Speaker 1: it's Simpsons reference number two. Oh yeah, nice. Uh but
Speaker 1: remember in The Great Escape too, they needed uh and
Speaker 1: of course we'll see this too. It's very dangerous job
Speaker 1: and they needed air. So they had them I think,
Speaker 1: uh fire billows, bellows, uh something pumping bellows, just to
Speaker 1: pump fresh air in there, because when you're hundred feet
Speaker 1: in a tunnel underground, especially the size of one the
Speaker 1: Great Escape, just like big enough for your body, you're
Speaker 1: gonna run out of air. Yeah, and well that's something
Speaker 1: that they ran into. We talked about. I don't remember
Speaker 1: what episode it was, but we were talking about building
Speaker 1: the Brooklyn Bridge. Um. They had these basically uh an
Speaker 1: upright coffee can that they dug the the the posts
Speaker 1: out of. Um. This is the same they ran in
Speaker 1: the same thing when they were building the the the
Speaker 1: tunnel underneath the Thames River. Thanks to Brunel, he built
Speaker 1: it with his son. Yeah, very shortet, but it took
Speaker 1: about eight or nine years. Um, and it was there
Speaker 1: was a shutdown for seven years because it ran out
Speaker 1: of money. But um, it was deep enough so that
Speaker 1: you had to pump compressed air in to keep the
Speaker 1: water out. And since there was compressed are you had
Speaker 1: to go through a series of airlocks or else you
Speaker 1: get the venture. And UM, I don't know if we've
Speaker 1: said this, it seems obvious, but the reason you're doing
Speaker 1: all of this is because digging into soft earth is
Speaker 1: problematic because you're leading edge is going to continually want
Speaker 1: to collapse on top of you unless you have pressurised
Speaker 1: there to keep the water at bay, and you have
Speaker 1: guys digging out through a support structure e g. A
Speaker 1: tunneling shield, sand hogs. That's messive method one, yes, and
Speaker 1: it's an old one and it's a good one. It's
Speaker 1: still in use today. Um. It has to be softer.
Speaker 1: You can't dig through bedrock because you know this thing
Speaker 1: moves through hydraulic jacks and there's guys digging. Um. If
Speaker 1: you run into like some serious rock, the best thing
Speaker 1: to use is called a tunnel boring machine. Yeah, if
Speaker 1: you've ever seen die Hard three? You get a good glimpse,
Speaker 1: Jeremy ir Yeah, which is a pretty good one. Um
Speaker 1: in fact, well actually yeah, one of only two good ones,
Speaker 1: Sam Jackson. Yeah, the first one and that one were
Speaker 1: pretty good. The second one and I didn't. All the
Speaker 1: other ones are just terrible. The second one, it wasn't
Speaker 1: so bad. It was all right. I like to see
Speaker 1: it was at the airport, Yeah, it was okay. I
Speaker 1: love any kind of airport disaster flick. Oh yeah, man,
Speaker 1: I'm crazy for those movies. Airport, airport, airport two, whatever, airplane.
Speaker 1: I love him. What about that bad Tom Hanks movie
Speaker 1: where he played the foreign guy that lived in the airport?
Speaker 1: I never saw that, But did you know Terminal? Yeah?
Speaker 1: Did you know that it's based on a real guy. Yeah,
Speaker 1: I didn't know that. I haven't seen the movie. That
Speaker 1: wasn't very good. The I think the fact that it
Speaker 1: was like kind of lighthearted and warm, that's not what
Speaker 1: the guy was like. Yeah. Well Spielberg plus Tom Hanks
Speaker 1: doing accents. Man, have you seen him doing Walt Disney? Yeah?
Speaker 1: I thought that It's okay in the preview, now I
Speaker 1: can't tell I did. I managed to get through only
Speaker 1: about twenty minutes of Cloud Atlas the other night. I
Speaker 1: just can't see Tom Hanks is like this Cockney rough ruffian. Well.
Speaker 1: I love the guy. He's an amazing actor. But it's
Speaker 1: just it didn't work. No, why did they do that?
Speaker 1: To know? Hodgman's got some good stories about Tom Hanks,
Speaker 1: by the way, I don't know if you should be
Speaker 1: telling people that. No, I'm not gonna tell the stories.
Speaker 1: I don't even know if you yes, all right man,
Speaker 1: that was a nice hank Sean sidebar. Tunnel boring machines
Speaker 1: Die Hard two three. Yeah, so these things are like
Speaker 1: a couple of stories tall. Yeah, they're amazing. They're they're
Speaker 1: tunnel boring machines is the right word for him. They're
Speaker 1: all inclusive machines. They cut, they support, and they build
Speaker 1: as they go along. They're magnificent as far as as
Speaker 1: mechanical engineering goes. Yeah, they have a spinning cutting head
Speaker 1: and he's basically huge giant steel wheels that twist and
Speaker 1: turn in different directions and then that whole thing turns
Speaker 1: and it's just a destructo mobile that goes straight ahead
Speaker 1: and uh lifts that pummels that rock and shoots it
Speaker 1: out on a conveyor behind. Yeah, just like a five
Speaker 1: valve a ship worm. And then uh, this is the
Speaker 1: part I didn't get that they're actually building it with
Speaker 1: an erector as it goes. Man, that's crazy. Yeah, it's
Speaker 1: all this one big machine that's you just basically pressed
Speaker 1: start and it goes forward. And they actually used tunnel
Speaker 1: boring machines, a pair of them for the chunnel construction,
Speaker 1: one from one side and one from the other side.
Speaker 1: And thanks to GPS, Yeah, good GPS um, they were
Speaker 1: able to keep them on a course for one another.
Speaker 1: First I thought missing, Yeah, the first thing I thought
Speaker 1: was I would end up like ten ft above. Oh man,
Speaker 1: I wouldn't even end up that close. Yeah, and you'd
Speaker 1: be screwed. You'd have to start all over. I would
Speaker 1: end up in Scotland. Well, it'd be great. We'd be
Speaker 1: like just tunnel up and get drunk distilleries. Uh. But
Speaker 1: luckily they had a lot smarter people than us working
Speaker 1: on the channel. Right. Um. They drive forward, Uh at
Speaker 1: a rate of about two and fifty per day. That's
Speaker 1: significant because we're talking like bedrock, you know, like if
Speaker 1: you if you were able to take away all of
Speaker 1: the Dirk and all of the water on Earth. What
Speaker 1: you would have is rock. That's the mantel, and that's
Speaker 1: what you're digging through. Is this rock it's made to
Speaker 1: support the earth exactly. Heck, it is the earth. Yeah,
Speaker 1: and um, this is what these machines dig through at
Speaker 1: a rate two fifty ft a day. That's impressive. Yeah,
Speaker 1: in they work, Apparently they're uh something this violent is
Speaker 1: prone to breaking down. So I guess when you have
Speaker 1: them up and running, that's a good thing. When they're down, then, um,
Speaker 1: you're obviously gonna be losing time. Did you see how
Speaker 1: the author of this article put it? I did. I
Speaker 1: didn't even want to comment. You want to go ahead? Well,
Speaker 1: he just says that they breakdown more often than he
Speaker 1: used jaguar, except he probably said jag earra jar. I
Speaker 1: didn't know that, or jaguars. Are they famous for not working? Yeah?
Speaker 1: Oh yeah, I really didn't know that. The older ones
Speaker 1: are well, that's like any old car, right, I think
Speaker 1: they they? And like if you w rabbits had like
Speaker 1: real bad track records. Remember the rabbit mhm or the cabriolet? Yeah,
Speaker 1: every story girl's favorite car, right? What else? Remember Looker? Yeah?
Speaker 1: It even said look car on the side. Yeah, it's
Speaker 1: French for the car, is it? Alright? So UM, did
Speaker 1: you know Josh that they are have been banning about
Speaker 1: the idea of a transit plant tunnel for decades. It's
Speaker 1: pretty awesome. I don't think it will ever happen though. No.
Speaker 1: They would be very costly because it would be the
Speaker 1: um It would be an immersion tube. But they wouldn't
Speaker 1: be able to go to the sea floor obviously, because
Speaker 1: that's just crazy. It would be tethered, floating essentially at
Speaker 1: about a hundred and fifty ft below the water, right
Speaker 1: dangling from a pontoon on the surface, and uh fifty
Speaker 1: four thousand football field side size sections. And that's how
Speaker 1: we're going to get into that in a minute. But
Speaker 1: that's how they work with these immersion tunnels. They do
Speaker 1: it one section at a time. It's just too much
Speaker 1: money and too much stuff. There's well, there's actually an
Speaker 1: immersion tube tunnel UM that's proposed in Norway across the
Speaker 1: Sogna Fiord. That sounds much more manageable than the Atlantic Ocean. Really,
Speaker 1: I mean, just the idea of this this ontoon getting
Speaker 1: pummeled by UM by cyclones and and just bad weather
Speaker 1: in general. Plus why do it these people who just
Speaker 1: want to drive to England from New York. I don't know.
Speaker 1: I don't know that the logic behind any advantage behind
Speaker 1: something like that. It just seems like it would just
Speaker 1: every every foot of it is a potential for it
Speaker 1: to just break and the whole thing's trashed. But the
Speaker 1: one in Norway is that an I T T an
Speaker 1: emerged tube tunnel. It is dangling from a pontoona bu
Speaker 1: that one's dangling, right, So that technology exists. Uh well,
Speaker 1: it's it's in proposal stage. And like the thing I saw,
Speaker 1: it was still probably kind of an overview, but they
Speaker 1: seemed pretty confident about it. They had like you know,
Speaker 1: titled charts and all that kind of stuff. But it's
Speaker 1: it's it's only something that's um like twenty kilometers or
Speaker 1: thirty kilometer or something like that. It's not all the
Speaker 1: way across the Atlantic Ocean, you know. All right, So
Speaker 1: I guess we should fully explain in the I T
Speaker 1: T then, which is our final way that you can
Speaker 1: tunnel underground and again my favorite, But before we get
Speaker 1: to it, let's do a message break and chuck now
Speaker 1: we finally get to talk about my favorite type of tunneling,
Speaker 1: the immersion tube tunnel. That's right. So these rubber seals
Speaker 1: have gina gaskets actually is what they're called. And you
Speaker 1: winch the two together and you pump the water out
Speaker 1: and these gaskets and seals the change and water pressure
Speaker 1: creates compresses them and creates an airtight seal. But it's underwater,
Speaker 1: so you would go in, say we want an underground
Speaker 1: tunnel going from this part of land that part of
Speaker 1: land under here, So we're just gonna go in. We're
Speaker 1: gonna dredge and dig and create a trench where we're
Speaker 1: gonna eventually put the tunnel. But we're gonna make the
Speaker 1: tunnel an individual piece of is here on dry land,
Speaker 1: usually at some sort of shipyard, and they're going to
Speaker 1: use the amount the equivalent of stealing concrete to make
Speaker 1: an average size ten story building. So just tip it
Speaker 1: on its side, and that's what your section looks like.
Speaker 1: That's one section um and then once the concrete cures
Speaker 1: after a month, we'll take it out to see in
Speaker 1: a pontoon crane, which is exactly what it sounds like
Speaker 1: that they're gigantic um. We seal it up first so
Speaker 1: that it floats and right. And then once we do
Speaker 1: get it over the site roughly where we want it,
Speaker 1: we will kind of start to sink it a little bit.
Speaker 1: Or I've also seen they'll weight it down, uh, and
Speaker 1: then they'll sink the thing and eventually they'll link it
Speaker 1: up to another segment, so they use winches to to
Speaker 1: pull one segment to another UM. And then these rubber
Speaker 1: gaskets hold the seal. And in this this bulkheads, these
Speaker 1: temporary bulkheads that are keeping the two um the two
Speaker 1: segments separate like inside the tunnel, you couldn't go through them.
Speaker 1: Yet you pump the water out, that changing air pressure
Speaker 1: compresses the rubber gaskets, forming a watertight seal. Then you
Speaker 1: remove the steel bulkheads. Bam, there's two connected segments of
Speaker 1: the tunnel. And you just keep adding and adding and
Speaker 1: adding and adding until you've created your prefab underwater tunnel.
Speaker 1: It's beautiful. Then you cover that up backfillet or something
Speaker 1: with rock. And we have a guy named W. J.
Speaker 1: Wilgas to thank for this because he invented it way
Speaker 1: back in the early nineteen hundreds. There's in early nineteen
Speaker 1: hundreds name w J. Wilgas look at my immerse tube
Speaker 1: tunnel where the world's fast, and everyone said, this is
Speaker 1: a pretty good idea. Yeah, and it um. He pioneered
Speaker 1: the technique when he built the Detroit River Railroad tunnel
Speaker 1: connecting uh Michigan to Canada. So technically the first immersed
Speaker 1: to tunnel is a sewer line in Boston in and
Speaker 1: when he built that railway line, that was like, Okay,
Speaker 1: this thing works because we've been shuttling poop in exactly
Speaker 1: and this is like, now we can do it with trains,
Speaker 1: and you are now the man of the hour, w J.
Speaker 1: Because what is a train except a lot of poop?
Speaker 1: You know, there's a similarity in but that has been
Speaker 1: the go to since then. Then there's been more than
Speaker 1: a hundred of these built in the twentieth century alone.
Speaker 1: Uh and that didn't even count the twenty first century.
Speaker 1: So I don't even know what's been going on the
Speaker 1: past thirteen years. I saw like an engineering thing that's
Speaker 1: that referred to him as rare. But I don't have
Speaker 1: the impression that they're rare at all, you know, I
Speaker 1: think they're kind of like the go to technique for
Speaker 1: any well as many as possible. Yeah. Well, the one
Speaker 1: advantage is, um, is that they you can make them
Speaker 1: any shape. You know. It's not like when you have
Speaker 1: a tunnel boring machine. Um, it's gonna have the shape
Speaker 1: of the tunnel borer or the same with the tunnel shields. Well, yeah,
Speaker 1: I guess it's the same. It's the size of the
Speaker 1: giant coffee can. But you can make a tunnel in
Speaker 1: the shape of a diamond if you wanted to. Well,
Speaker 1: maybe not diamond. Well you could be kind of crazy,
Speaker 1: be a big waste of money. But yeah, you can
Speaker 1: take any shape, and um, you will also have to
Speaker 1: use some of those other methods eventually, because this is
Speaker 1: just for the what's along the bottom. To get down
Speaker 1: to that section and then out the entrances and exits,
Speaker 1: you're gonna have to use some other methods, right, you
Speaker 1: might have to tunnel through through some sort of rock
Speaker 1: or whatever. But yeah, when you put these tunnel segments
Speaker 1: in and you pump the water out of the the
Speaker 1: the chamber that connects the two, you take the bulkheads off,
Speaker 1: Like there's your finished tunnel right there. I mean, you've
Speaker 1: got the floors, the walls, the ceiling roadway. You go
Speaker 1: in and put the wiring in and the lighting and
Speaker 1: all that stuff afterward. But your tunnels set. Yeah, I
Speaker 1: just think it's neat. I think it's very neat. Um
Speaker 1: what else you got? I got nothing else. There's one
Speaker 1: proposed right now that will be the long gus immersed
Speaker 1: tube tunnel in the world when it's finished in two
Speaker 1: thousand sixteen. There's a fifty kilometer bridge that connects or
Speaker 1: will connect Hong Kong to Macau, and part of it
Speaker 1: is a six point seven kilometer long immersed tube tunnel
Speaker 1: which will probably be real nice, awesome. Yeah, I guess
Speaker 1: that's it. All right, Go forth and build tunnels, Go
Speaker 1: forth and build underwater tunnels. Let's see. If you want
Speaker 1: to learn more about underwater tunnels, you can type that
Speaker 1: word into the search bar at how stuff works dot com. Uh.
Speaker 1: And since I said search part, that means it's time
Speaker 1: for listener mail. All right, I'm gonna call this another
Speaker 1: chess email, and this is gonna be it on the
Speaker 1: chess emails. But thank you to everyone who wrote in
Speaker 1: about your chess strategies and stuff. It's pretty great. Hey, guys,
Speaker 1: thanks for doing the podcast on chess. It's a great game.
Speaker 1: Here are a few things that you sort of missed jumping.
Speaker 1: Josh implied or maybe even outright said that a night
Speaker 1: only appears to jump over other pieces, it really just
Speaker 1: goes around them. Nights actually can jump over other pieces.
Speaker 1: For example, if you were so inclined on your very
Speaker 1: first move, you could jump your Night over your ponds
Speaker 1: and place it in front of the rest of your pieces.
Speaker 1: There aren't any empty spaces to take your Night around
Speaker 1: your islands in the stream, So that's jumping baby. A
Speaker 1: little more on castling a couple of things. As you said,
Speaker 1: you cannot castle if it either if either piece involved
Speaker 1: has moved during the game. You also can't do it
Speaker 1: if the king is in check or has to move
Speaker 1: through check to castle. So the opposition queen is attacking
Speaker 1: a square that the king has to go through the
Speaker 1: castle it it cannot be done. Yeah, yeah, you got that.
Speaker 1: You should probably all go back rewind that and listen
Speaker 1: to it again. That's right, and um that's from Matt
Speaker 1: in Pittsburgh. I'm sorry in l A via Pittsburgh, but
Speaker 1: I did want to point out someone else in in
Speaker 1: um another correction. I think we we got them pawn
Speaker 1: promotion right, like if you make get your pawn all
Speaker 1: the way to the other end of the table. But um,
Speaker 1: I don't think we pointed out that you can only
Speaker 1: promote it to a piece that you've already lost. Oh no,
Speaker 1: we definitely did not. In other words, you can't have
Speaker 1: two queens. But if you specifically said you have two queens,
Speaker 1: oh did Yeah, Okay, I genuinely didn't know that. I
Speaker 1: thought that. I didn't catch that. I knew that, but
Speaker 1: I didn't catch it. So that was from someone else.
Speaker 1: But thank you Matt in l A via Pittsburgh. Yeah,
Speaker 1: he also described on poissant, but I think we've already
Speaker 1: taken that up in another listener mail. So yeah, thanks
Speaker 1: for all the corrections on Chester. Yeah, everybody, thank you
Speaker 1: very much. If you want to get in touch with us,
Speaker 1: tweet to us. Our Twitter handle is s y s
Speaker 1: K Podcast, our Facebook dot com pages slash Stuff you
Speaker 1: Should Know. Ah, you can send us an email to
Speaker 1: Stuff Podcast at Discovery dot com and as always, joined
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