0:00:02 > 0:00:05- Welcome to the genius world of... - BOTH:- Monster Engineering.
0:00:05 > 0:00:06THEY SCREAM
0:00:06 > 0:00:10Each show, we're going to introduce you to three geniuses...
0:00:10 > 0:00:12- Yeah, wow!- Oooh!
0:00:12 > 0:00:16..whose ideas have quite literally built the world.
0:00:16 > 0:00:20We put all their epic brilliance to the test...
0:00:20 > 0:00:21Hit it, hit it!
0:00:21 > 0:00:24..when we tackle our own genius Monster Build.
0:00:24 > 0:00:25Don't you dare demolish this!
0:00:27 > 0:00:29Going higher...
0:00:29 > 0:00:30Why is it swinging?
0:00:30 > 0:00:32..faster...
0:00:32 > 0:00:34..and scarier...
0:00:34 > 0:00:35Oh, no!
0:00:35 > 0:00:37..all in the name of science.
0:00:37 > 0:00:41That is a massive piece of construction.
0:00:41 > 0:00:42What could possibly go wrong?
0:00:46 > 0:00:49On today's show, we're going up...
0:00:49 > 0:00:51..down...
0:00:51 > 0:00:53It's unbelievably fast!
0:00:53 > 0:00:54..and across.
0:00:54 > 0:00:56- Go.- Come on! Run!
0:00:56 > 0:00:59..as we uncover the secrets of epic bridges.
0:00:59 > 0:01:03- Wow!- Look at that. It really is a Monster Build, that, isn't it, eh?
0:01:03 > 0:01:06- This is... - Absolute Genius!
0:01:42 > 0:01:45Here's a question for you. How do you get millions of people
0:01:45 > 0:01:48from the city over there to the other side of the bay?
0:01:48 > 0:01:50- Swim it.- What? No, there's sharks!
0:01:50 > 0:01:51- Tunnel it.- Don't be ridiculous!
0:01:51 > 0:01:53- Bridge it.- Who is she? - No, BRIDGE it!
0:01:53 > 0:01:55Oh, bridge it. Yes, I see.
0:01:56 > 0:02:00This is the Golden Gate Bridge in San Francisco.
0:02:00 > 0:02:03And today's show is all about, you guessed it...
0:02:03 > 0:02:04- BOTH:- Bridges!
0:02:05 > 0:02:08People have always needed to get from A to B,
0:02:08 > 0:02:10but sometimes, there's a big problem...
0:02:10 > 0:02:12This is a big problem.
0:02:12 > 0:02:14..which forces engineers to get thinking.
0:02:14 > 0:02:17- And the simplest solution, build a bridge.- Bravo!
0:02:17 > 0:02:21They are a brilliant fix whenever nature gets in our way.
0:02:21 > 0:02:24- Ooh, that's got it.- As we've become smarter, bridges have become longer,
0:02:24 > 0:02:26taller and stronger.
0:02:26 > 0:02:30Today, there is almost no gap too big to span.
0:02:32 > 0:02:34But let's rewind the clock.
0:02:34 > 0:02:36When it came to genius feats of engineering,
0:02:36 > 0:02:39the Ancient Romans were hard to beat.
0:02:39 > 0:02:42From amphitheatres to aqueducts,
0:02:42 > 0:02:46they knew a thing or two about building stuff that lasts.
0:02:46 > 0:02:49We've come to the south of France to see one of the biggest
0:02:49 > 0:02:52and most impressive examples of Roman engineering in the world.
0:02:52 > 0:02:54Yeah, it's such a popular tourist attraction,
0:02:54 > 0:02:58that it's even found its way onto the back of a five euro note.
0:02:58 > 0:03:00Pretty good, eh? Have a look. It's amazing.
0:03:00 > 0:03:04- This is the Pont du Gard. - The bridge over the River Gard.
0:03:07 > 0:03:10The Pont du Gard has stood in this valley
0:03:10 > 0:03:12since the first century AD.
0:03:12 > 0:03:15It survived everything, from floods to gale-force winds,
0:03:15 > 0:03:19and today, it's one of France's most famous landmarks.
0:03:20 > 0:03:22And there's only one way to visit
0:03:22 > 0:03:24this "magnifique" bit of construction.
0:03:24 > 0:03:26- See you later.- It's not a gondola.
0:03:26 > 0:03:28# Just one Cornetto... #
0:03:28 > 0:03:30It's not a gondola.
0:03:30 > 0:03:31Dom, just sit down.
0:03:34 > 0:03:36It's even more impressive from this angle.
0:03:38 > 0:03:41And if it wasn't for our first genius's massive brain,
0:03:41 > 0:03:44the secrets to the strength of the Pont du Gard would have been lost.
0:03:44 > 0:03:47Introducing author, architect, engineer
0:03:47 > 0:03:49and all-round Roman boffin,
0:03:49 > 0:03:52- it's... - BOTH:- Vitruvius!
0:03:52 > 0:03:54You've got my beard all wet.
0:03:54 > 0:03:57Yeah, but you've got a dry moustache.
0:03:57 > 0:03:59Genius helper Alejandro Mendez Graf
0:03:59 > 0:04:03has arranged access-all-areas to this Roman marvel.
0:04:04 > 0:04:07- Hi, Alejandro. How you doing? - Nice to see you.- Welcome.
0:04:07 > 0:04:09It'd be great to have a look around the bridge.
0:04:10 > 0:04:13And we're starting, where else, but right at the very top.
0:04:16 > 0:04:19Almost 50 metres above the valley floor.
0:04:23 > 0:04:25Alejandro, it's in really good nick, this place,
0:04:25 > 0:04:26but how many years old is it?
0:04:26 > 0:04:30- It's 2,000 years old.- 2,000?! - What was it built for, though?
0:04:30 > 0:04:34This aqueduct was built to have running water in the city of Nimes.
0:04:34 > 0:04:36So this whole construction was made
0:04:36 > 0:04:39to get water from that side of the river
0:04:39 > 0:04:42all the way through this... I suppose you'd call it a tunnel,
0:04:42 > 0:04:45over to the other side, so people there could get fresh water?
0:04:45 > 0:04:47- That's right.- Wow!
0:04:47 > 0:04:51The Pont du Gard's three layers of arches aren't just for show.
0:04:51 > 0:04:53This was the only way that the Romans
0:04:53 > 0:04:56could build high enough to keep the pipe carrying their fresh water
0:04:56 > 0:04:58level with the surrounding hills.
0:04:59 > 0:05:01We are inside the pipe.
0:05:01 > 0:05:04You have to imagine this place with water coming almost up to the roof.
0:05:04 > 0:05:06Is this tunnel all watertight?
0:05:06 > 0:05:09This tunnel is watertight, thanks to the mortar
0:05:09 > 0:05:10which was on the walls here.
0:05:12 > 0:05:16The Romans invented a super-strong mortar,
0:05:16 > 0:05:18made from crushed volcanic rock.
0:05:18 > 0:05:21When added to the walls of the pipe we've just seen,
0:05:21 > 0:05:25it stuck the stones together and stopped the water leaking out.
0:05:25 > 0:05:29Clever, but they didn't use it all over the bridge,
0:05:29 > 0:05:31as we are about to discover.
0:05:31 > 0:05:33So, obviously, it's been well put-together.
0:05:33 > 0:05:34How is it actually constructed?
0:05:34 > 0:05:36The stones which are the building,
0:05:36 > 0:05:40our stones are coming from a quarry at about 600 metres just downriver.
0:05:40 > 0:05:42They were transported up to here.
0:05:42 > 0:05:45All the big stones are held together without mortar.
0:05:45 > 0:05:48So there's no sand and cement, no bonding at all.
0:05:48 > 0:05:49Not at all, and mainly,
0:05:49 > 0:05:52that concerns the first and second level.
0:05:53 > 0:05:55Amazing! But also very strange.
0:05:56 > 0:06:02After all, this massive stone bridge weighs over 50,000 tonnes!
0:06:02 > 0:06:05So we understand that the top of the bridge, the aqueduct,
0:06:05 > 0:06:06is held together with mortar,
0:06:06 > 0:06:08but what about the rest of the bridge?
0:06:08 > 0:06:11How does it stay up? What's sticking the bricks together?
0:06:11 > 0:06:12There's only one way to find out.
0:06:12 > 0:06:14Le Fran!
0:06:16 > 0:06:18Meet Fran!
0:06:18 > 0:06:19- Our scientist friend...- Go!
0:06:19 > 0:06:24..who can explain things in a way that even we can understand.
0:06:24 > 0:06:25It worked!
0:06:25 > 0:06:28She loves a good experiment.
0:06:29 > 0:06:34- And best of all, she pops up... - Hello!- ..whenever we need her.
0:06:34 > 0:06:37Franny, everybody! Eh?
0:06:37 > 0:06:39Franny, we need your help!
0:06:39 > 0:06:42The Pont du Gard was beautiful.
0:06:42 > 0:06:45But the bottom part of it was stuck together with nothing,
0:06:45 > 0:06:46- not a saucisson!- Rien!
0:06:46 > 0:06:48You think it was stuck together with nothing?
0:06:48 > 0:06:51Well, in fact, it's stuck together with friction.
0:06:51 > 0:06:53- Friction.- Yeah, but friction slows moving objects down.
0:06:53 > 0:06:56It does, but friction can also stick objects together
0:06:56 > 0:06:59and stop them from moving completely.
0:06:59 > 0:07:01I want to show you with this stuff.
0:07:01 > 0:07:04Right, so what are you going to do, cook us a curry?
0:07:04 > 0:07:06- I've got a little bit of a challenge for you.- Yes.
0:07:06 > 0:07:09I want to see how much of this rice you can pick up
0:07:09 > 0:07:11- just using this stick.- What?!
0:07:11 > 0:07:13- Give it a try.- You go.
0:07:13 > 0:07:17- Go on. Challenge. - Just in different ways...
0:07:17 > 0:07:20- See how much rice you can pick up. - How much rice have you got?
0:07:20 > 0:07:22- Oh! Oh!- Ah-ah-ah-ah-ah!
0:07:22 > 0:07:24No, no, no!
0:07:24 > 0:07:26- Oh!- Aw!- Give up. Silly experiment!
0:07:26 > 0:07:28Fran, why you not use pasta?
0:07:28 > 0:07:31What if I told you that using friction,
0:07:31 > 0:07:33we could pick up the whole of this jar of rice.
0:07:33 > 0:07:35Not possible - you can't use that stick to pick up all that rice.
0:07:35 > 0:07:38- Well, we'll see.- No. - So, Dick, take this.
0:07:38 > 0:07:40Just jab the stick in a few times. Just try it.
0:07:40 > 0:07:42- Jab it?- Just jab it in.
0:07:42 > 0:07:45And lift it out and then put it in.
0:07:45 > 0:07:47And each time you are doing that,
0:07:47 > 0:07:49it's jiggling the rice about in such a way
0:07:49 > 0:07:53that more and more rice is touching the stick,
0:07:53 > 0:07:57and, eventually, there'll be enough rice touching the stick
0:07:57 > 0:07:59for the friction between them to be enough
0:07:59 > 0:08:01to lift up the whole of the jar.
0:08:01 > 0:08:02- I say no.- Let's see.
0:08:02 > 0:08:04Lift it. Lift it right out.
0:08:04 > 0:08:06So you've got to lift it right out
0:08:06 > 0:08:07and then put it right in
0:08:07 > 0:08:09and then lift it out
0:08:09 > 0:08:10and then put it in.
0:08:10 > 0:08:13Oh, oh, go on! Go on!
0:08:13 > 0:08:15Go on!
0:08:15 > 0:08:17THEY CHEER AND LAUGH
0:08:18 > 0:08:21Oh, look at that! Friction!
0:08:26 > 0:08:29FRAN SCREAMS, DICK GROANS
0:08:29 > 0:08:32Mamma mia, you make a big mess!
0:08:32 > 0:08:36But how does that relate to stones holding together a bridge?
0:08:36 > 0:08:38What the Roman engineers did,
0:08:38 > 0:08:42they cut the stones really precisely so they fitted perfectly together
0:08:42 > 0:08:45and that meant there was a lot of them touching each other
0:08:45 > 0:08:49and touching means more friction, which means the friction was enough
0:08:49 > 0:08:52to hold the bridge up without mortar.
0:08:52 > 0:08:54And the technique is called opus quadratum.
0:08:54 > 0:08:57- BOTH: Told you! - And the reason we know about it
0:08:57 > 0:08:59is because of the writings of Vitruvius.
0:08:59 > 0:09:00VITRUVIUS CHUCKLES
0:09:01 > 0:09:04Now we understand how it was made,
0:09:04 > 0:09:07the Pont du Gard is even more spectacular.
0:09:07 > 0:09:09It's amazing to think that, 2,000 years later,
0:09:09 > 0:09:11that bridge is still standing,
0:09:11 > 0:09:13thanks to the genius way it was built.
0:09:13 > 0:09:15And if it wasn't for this man,
0:09:15 > 0:09:16we wouldn't know how the Romans built it.
0:09:16 > 0:09:19Vitruvius, you are a rock-solid genius.
0:09:19 > 0:09:22Oh, yeah, boys! You can't knock me down!
0:09:22 > 0:09:24Ohh... Argh!
0:09:25 > 0:09:26Next!
0:09:29 > 0:09:31After the Romans,
0:09:31 > 0:09:34things went a bit quiet in the world of bridge building.
0:09:34 > 0:09:38In fact, they went A LOT quiet for nearly 2,000 years!
0:09:38 > 0:09:40But from the late 1700s,
0:09:40 > 0:09:43engineers had cast iron and then steel at their disposal.
0:09:43 > 0:09:47These new materials set off a golden age of bridge building.
0:09:47 > 0:09:51And nowhere went bigger on bridges than New York.
0:09:54 > 0:09:56That's the Brooklyn Bridge, crossing the East river,
0:09:56 > 0:09:58linking Manhattan to Brooklyn.
0:09:58 > 0:10:00Yeah, it's a suspension bridge
0:10:00 > 0:10:02and when it was first built in the late 1800s,
0:10:02 > 0:10:05it was the longest of its type in the world.
0:10:05 > 0:10:06But without our next genius,
0:10:06 > 0:10:09that incredible structure would never have been built.
0:10:09 > 0:10:12Well, who is it? Don't leave me hanging!
0:10:12 > 0:10:15That's exactly what we're doing.
0:10:15 > 0:10:19Introducing to you, the man who created twisted steel cable...
0:10:19 > 0:10:21- Twisted steel cable?- Yes,
0:10:21 > 0:10:25- it's the thing we're going to fly down in a minute at 100mph.- Great(!)
0:10:25 > 0:10:27..Wilhelm Albert!
0:10:27 > 0:10:29Happy flightings, Dick und Dom!
0:10:29 > 0:10:32- Oh, no!- Whoa!- Nooooo!
0:10:33 > 0:10:34HE SCREAMS
0:10:34 > 0:10:35Stop that. That's silly.
0:10:35 > 0:10:37We'll come back to that terrifying moment later.
0:10:39 > 0:10:42Wilhelm Albert was in charge of a German mine.
0:10:42 > 0:10:45He was fed up by the number of accidents caused
0:10:45 > 0:10:49when the iron link chains, used to haul heavy loads, snapped.
0:10:49 > 0:10:50His genius idea -
0:10:50 > 0:10:56a much stronger twisted steel cable, originally known as Albert Rope.
0:10:56 > 0:10:59Today, Albert's invention can be found
0:10:59 > 0:11:01on many of the world's most famous bridges,
0:11:01 > 0:11:03even ones that are still being constructed.
0:11:05 > 0:11:08- Wow!- Look at that. It really is a Monster Build, that, isn't it?
0:11:08 > 0:11:10This is the Queensferry Crossing,
0:11:10 > 0:11:12a new road bridge currently being built
0:11:12 > 0:11:15over the Firth of Forth near Edinburgh.
0:11:15 > 0:11:18When it opens, this 2.7km span
0:11:18 > 0:11:21will be the longest three-towered cable-stayed bridge
0:11:21 > 0:11:23in the entire world.
0:11:24 > 0:11:27That is a MASSIVE piece of construction.
0:11:27 > 0:11:30We've been given special permission to visit the deck
0:11:30 > 0:11:32where the road will be built once the bridge is finished.
0:11:32 > 0:11:34Wouldn't want his job! Look at him.
0:11:34 > 0:11:36Look at him up there, look at his job.
0:11:36 > 0:11:38He's just dangling!
0:11:38 > 0:11:40Right. Goodbye, everyone.
0:11:41 > 0:11:45The deck is suspended 55 metres above the water.
0:11:45 > 0:11:48That's about the height of 11 double-decker buses.
0:11:48 > 0:11:50- Whoa!- Whoa! Hey!- High!
0:11:53 > 0:11:56This is the THIRD bridge to cross the FORTH Estuary...
0:11:56 > 0:12:00Get it? ..joining the incredible 19th-century rail bridge
0:12:00 > 0:12:02and the 1960s road bridge.
0:12:04 > 0:12:08This project is too mammoth for just one genius helper, so we've got two.
0:12:10 > 0:12:14Gerard Kiely and Ralph Hildebrand!
0:12:16 > 0:12:19So, the cables on this bridge, what are they used for?
0:12:19 > 0:12:22So, what we're standing on right now is the road deck of the bridge
0:12:22 > 0:12:25and the cars will be driving across here in a couple of months' time.
0:12:25 > 0:12:28- Yeah.- So, to stop the cars falling into the river,
0:12:28 > 0:12:32these cables stop the deck and they keep it floating in the air.
0:12:32 > 0:12:34How much weight will these cables be taking?
0:12:34 > 0:12:39In total, all of the bridge deck is going to be close to 100,000 tonnes.
0:12:39 > 0:12:42- Unimaginable. - That's like 50,000 two-tonne cars.
0:12:42 > 0:12:45- What?- A lot.- And it's all thanks to the genius way
0:12:45 > 0:12:47that these cables are constructed, right?
0:12:47 > 0:12:50Correct. On each strand, what we have here,
0:12:50 > 0:12:51we have seven wires.
0:12:51 > 0:12:55We have one wire in the middle and you have six wires bent around
0:12:55 > 0:12:57and they are holding a lot of force together. Yeah?
0:12:57 > 0:13:02So in each one of the stay cables, we have between 55 and 109 pieces.
0:13:02 > 0:13:0735,000 miles of strength inside, so they can take a lot of load.
0:13:07 > 0:13:10But if that was just one central wire,
0:13:10 > 0:13:12and all the other wires around it were just running straight along,
0:13:12 > 0:13:15it wouldn't be able to carry as much weight, right?
0:13:15 > 0:13:16It's the fact that they are twisted,
0:13:16 > 0:13:18that enables to take the massive amount of weight.
0:13:18 > 0:13:21- Correct.- And this is all down to Wilhelm Albert's genius?
0:13:21 > 0:13:23Without him, there wouldn't be a bridge like this?
0:13:23 > 0:13:25Exactly. Without him, it would not exist.
0:13:27 > 0:13:31Suspension and cable-stayed bridges, like the one we've just seen,
0:13:31 > 0:13:35can safely carry massive loads over big gaps.
0:13:35 > 0:13:37Whilst vertical forces run up and down the towers,
0:13:37 > 0:13:41Wilhelm Albert's twisted steel cables are being stretched
0:13:41 > 0:13:45between the deck and tower, creating a rigid structure.
0:13:45 > 0:13:48That means the roadway which carries vehicles
0:13:48 > 0:13:50is locked securely in place.
0:13:50 > 0:13:55- There's no denying Albert's genius, but what better...- Or scarier!
0:13:55 > 0:13:57..way to put his invention to the test than this -
0:13:57 > 0:14:03a mile-long zip wire, suspended more than 150 metres above a quarry?!
0:14:07 > 0:14:10- No!- Whoa!
0:14:17 > 0:14:20So fast!
0:14:21 > 0:14:23It's unbelievably fast!
0:14:23 > 0:14:25Aaargh!
0:14:25 > 0:14:27Oh, isn't he brave?! I'm fine, though,
0:14:27 > 0:14:29because this stuff is strong enough
0:14:29 > 0:14:33to hold up to 100,000 tonnes of bridge, remember!
0:14:33 > 0:14:34Wey-hey!
0:14:34 > 0:14:35Oh, wow, ow!
0:14:35 > 0:14:37Urgh...
0:14:37 > 0:14:39What?! DOM LAUGHS
0:14:39 > 0:14:41- That was amazing! - Not doing it again.
0:14:41 > 0:14:43- It was brilliant!- It was fast.
0:14:43 > 0:14:46- It's like you're flying.- Just fast. I just remember it being fast.
0:14:46 > 0:14:49Just to think that twisted steel cable was the one thing
0:14:49 > 0:14:51that was responsible for you not dropping.
0:14:51 > 0:14:55All day my lovely cable will keep you in the air!
0:14:55 > 0:14:57Up to the top again. Come on!
0:14:59 > 0:15:02- Coming up...- Go! - We are put through our paces...
0:15:02 > 0:15:03Oh, it's hard work, this.
0:15:03 > 0:15:05..in a military Monster Build.
0:15:05 > 0:15:07PEOPLE SHOUT
0:15:07 > 0:15:09Push it, push it.
0:15:11 > 0:15:12But now it's time for some...
0:15:15 > 0:15:17This London Bridge isn't falling down.
0:15:17 > 0:15:19In fact, it's gently unrolling.
0:15:19 > 0:15:21Thanks to nifty hydraulics,
0:15:21 > 0:15:23this link across the Grand Union Canal
0:15:23 > 0:15:26can be rolled and unrolled to allow boats to pass.
0:15:28 > 0:15:30This suspension bridge in China
0:15:30 > 0:15:34is paved with 99 panes of extra-thick glass.
0:15:34 > 0:15:38It's 300 metres above the ground, so, in case of emergency...
0:15:39 > 0:15:41..definitely don't break here!
0:15:42 > 0:15:45It looks like something you'd see at a funfair,
0:15:45 > 0:15:49but this is the Tees Transporter Bridge in Middlesbrough.
0:15:49 > 0:15:53This moving gondola can carry up to 200 people, or 9 cars.
0:15:53 > 0:15:55Scream if you want to go faster!
0:15:55 > 0:15:57SCREAMING
0:15:57 > 0:15:59We've seen how genius ideas from the past
0:15:59 > 0:16:02have helped create some truly breathtaking bridges.
0:16:02 > 0:16:04That's the past, but what about the future?
0:16:04 > 0:16:06Well, let's meet our next genius.
0:16:06 > 0:16:07Mr Chuck Hull.
0:16:07 > 0:16:09Hey, how you doing, boys?
0:16:09 > 0:16:12- Yes, very well, thank you. - Yes, thank you very much, very nice.
0:16:15 > 0:16:18Back in the 1980s, Charles "Chuck" Hull
0:16:18 > 0:16:22was working for a company that put thin plastic coverings on furniture.
0:16:22 > 0:16:24In a spark of genius,
0:16:24 > 0:16:27Chuck tried putting thousands of thin layers of plastic
0:16:27 > 0:16:30on top of each other, before using light to etch the blocks
0:16:30 > 0:16:33into simple three-dimensional shapes.
0:16:33 > 0:16:34Mmm! Smells ready!
0:16:34 > 0:16:373-D printing was born and now, over 30 years later,
0:16:37 > 0:16:40it's beginning to revolutionise the way we build.
0:16:40 > 0:16:42Whee! Gnarly!
0:16:47 > 0:16:50The Dutch city of Amsterdam is famous for its canals
0:16:50 > 0:16:54and is already home to over 1,000 bridges.
0:16:54 > 0:16:56Look, there's one. See, told you!
0:16:56 > 0:16:59Beginning to take shape in this warehouse behind us
0:16:59 > 0:17:01is one of the newest and strangest of the lot.
0:17:01 > 0:17:07Welcome to the home of the world's first-ever 3-D printed bridge.
0:17:07 > 0:17:10- What?- What? 3-D printed bridge? - Is it?- Go figure.
0:17:13 > 0:17:15- What is it?- Bridges.- Bridges.
0:17:21 > 0:17:25To find out more, we're meeting Tim Geurtjens.
0:17:25 > 0:17:27He works for the company who are making the bridge.
0:17:29 > 0:17:32- Tim, hi. Lovely to meet you. - Hi, Tim.- Hi, welcome.
0:17:32 > 0:17:34Could you tell us what 3D printing is?
0:17:34 > 0:17:36How is this machine working behind us?
0:17:36 > 0:17:39We have a robotic arm which can move freely in the air
0:17:39 > 0:17:42and it squeezes out a little bit of molten metal at the same time.
0:17:42 > 0:17:45It's almost like drawing in midair. You can just draw lines in the air.
0:17:45 > 0:17:47It can move any direction - left, right, up, down?
0:17:47 > 0:17:48Anywhere. Yeah.
0:17:48 > 0:17:52And so it ejects layers and layers and layers of liquid metal
0:17:52 > 0:17:55into any shape that you programme on a computer?
0:17:55 > 0:17:56Yeah, exactly.
0:17:59 > 0:18:01Mind-blowing!
0:18:01 > 0:18:06Tim and his robots have even managed to 3D print a bike frame.
0:18:06 > 0:18:09So that whole frame is 3D printed?
0:18:09 > 0:18:11- It is completely 3-D printed, out of stainless steel.- What?!
0:18:11 > 0:18:14- Right, can I have a ride? - Sure. Give it a go.- OK.
0:18:14 > 0:18:17- Oh, it's pretty heavy! - Is it heavy?- Yeah.
0:18:17 > 0:18:21- No brakes.- No, no brakes. No, we couldn't print those.
0:18:21 > 0:18:24- Let's see what happens.- So, what are you going to do?- Cycle it!
0:18:24 > 0:18:26- You've never ridden it before! - My legs are too short!
0:18:26 > 0:18:29- Look at that.- It's going very well.- Absolutely.
0:18:29 > 0:18:31- Solid as a rock.- Yeah.
0:18:31 > 0:18:34# I like to ride my bicycle! #
0:18:34 > 0:18:36- BIKE BELL RINGS - Very sturdy.
0:18:36 > 0:18:38I mean, it's like any other bike.
0:18:38 > 0:18:41Is it? Works a treat!
0:18:41 > 0:18:43- There's no brakes!- Stop!
0:18:43 > 0:18:45Aaargh!
0:18:45 > 0:18:48But it's bridges we are interested in, not bikes.
0:18:48 > 0:18:51Of course, your big project is building a bridge.
0:18:51 > 0:18:54- How do you go about that? - Well, I mean, obviously,
0:18:54 > 0:18:56the robot is not big enough to build a full bridge.
0:18:56 > 0:18:57So when the robot goes out of reach,
0:18:57 > 0:18:59we just move the robot a little bit further,
0:18:59 > 0:19:01and then we continue printing.
0:19:01 > 0:19:04So by doing that, we can print... unlimited in size, almost.
0:19:06 > 0:19:08So, this is a bridge that we printed before.
0:19:08 > 0:19:10It's a miniature version of the bridge we're going to print.
0:19:10 > 0:19:13It doesn't look strong enough to be able to take the weight of a person.
0:19:13 > 0:19:16- May we?- Yeah, sure, sure, sure. Be my guest.
0:19:18 > 0:19:21- It's really sturdy! - Is it not bending under your feet?
0:19:21 > 0:19:23- No, it's perfect. - Can two of us go on it?
0:19:23 > 0:19:25- Sure. Yeah, you can... - Oh, it's fine. It's really bizarre.
0:19:25 > 0:19:29It looks really thin and flimsy, but it's actually as strong as anything.
0:19:29 > 0:19:31- You can even jump up and down on it. - Don't do that!- All right.
0:19:31 > 0:19:33So, what are the ambitions for this?
0:19:33 > 0:19:36This is a small bridge. What about the big one?
0:19:36 > 0:19:38Well, the big one is going to be, obviously, a lot bigger,
0:19:38 > 0:19:39it will be about eight metres.
0:19:39 > 0:19:43It's going to be able to support bicycles, pedestrians.
0:19:43 > 0:19:46In the future, do you think we'd see 3-D printed bridges
0:19:46 > 0:19:49spanning big rivers? You can put lorries on there and cars?
0:19:49 > 0:19:50Yeah, I mean, yeah, as I said,
0:19:50 > 0:19:53it's just as strong as any other stainless steel,
0:19:53 > 0:19:56so you could print it, theoretically, as big as you want.
0:19:56 > 0:19:59We think your imagination should be your only limitation,
0:19:59 > 0:20:01so, with 3-D printing, you can print anything.
0:20:01 > 0:20:04The full-size bridge is still a work in progress,
0:20:04 > 0:20:05but when it's finished,
0:20:05 > 0:20:08it will span a canal in central Amsterdam.
0:20:08 > 0:20:12It's been a real eye-opener, looking at the future of bridge building.
0:20:12 > 0:20:14And none of this would have been possible
0:20:14 > 0:20:16without the 3D mind of Chuck Hull.
0:20:16 > 0:20:19Shucks, you're making me blush!
0:20:19 > 0:20:22- A 3-D printed... - BOTH:- Absolute Genius!
0:20:27 > 0:20:30Thanks to the three geniuses we've met in this show...
0:20:30 > 0:20:33That is a MASSIVE piece of construction.
0:20:33 > 0:20:36..bridging gaps that WERE impossible...
0:20:36 > 0:20:38Look at it! Wow!
0:20:38 > 0:20:40..now feel like a hop and a step.
0:20:43 > 0:20:45It's time for our Genius Monster Build Challenge.
0:20:45 > 0:20:48And we're joining forces with the real deal.
0:20:48 > 0:20:50The British Army's Royal Engineers.
0:20:56 > 0:20:59Engineers have played an important role in armies
0:20:59 > 0:21:02ever since Roman times, and the Royal Engineers
0:21:02 > 0:21:06have been a key part of the British Army for 300 years.
0:21:06 > 0:21:07We've come to the home of
0:21:07 > 0:21:103 Royal School of Military Engineering in Surrey.
0:21:10 > 0:21:132,000 soldiers are trained here every year
0:21:13 > 0:21:17and they use their skills all over the world. We'd better behave,
0:21:17 > 0:21:20because we're under the command of Captain Luke Parker.
0:21:23 > 0:21:25- Captain Parker!- Captain Parker, sir!
0:21:25 > 0:21:27What exactly do engineers do in the Army?
0:21:27 > 0:21:31The engineers allow the Army to live, to move and to fight.
0:21:31 > 0:21:34They learn how to build bridges, create obstacles, breach minefields.
0:21:34 > 0:21:35You mentioned bridges.
0:21:35 > 0:21:38What kind of conditions would they have to build a bridge under?
0:21:38 > 0:21:40In almost any conceivable conditions.
0:21:40 > 0:21:43What? I take it they're not exactly light, these bridges, as well?
0:21:43 > 0:21:46No, the bridges are extremely heavy and it takes a soldier
0:21:46 > 0:21:48ten weeks to learn how to build all these bridges.
0:21:48 > 0:21:50- We haven't got that long. - You've not got that long.
0:21:50 > 0:21:53However, what we do have is a lake that needs crossing.
0:21:53 > 0:21:56We've got a bridge that needs building and not much time to do it.
0:21:56 > 0:21:59- To the bridge! - To this bridge build.- All right.
0:22:00 > 0:22:03Get ready for Team Dick versus Team Dom
0:22:03 > 0:22:06in a frantic race to cross a lake.
0:22:06 > 0:22:09Working alongside a highly trained team of Royal Engineers,
0:22:09 > 0:22:12we must each build a 22 metre-long footbridge.
0:22:12 > 0:22:14The first team to finish their bridge and use it
0:22:14 > 0:22:16to move a casualty on a stretcher
0:22:16 > 0:22:18from one bank of the lake to the other
0:22:18 > 0:22:20will be crowned the winners.
0:22:20 > 0:22:22Hooray, I've won!
0:22:23 > 0:22:27There's just time for a few last-minute preparations.
0:22:31 > 0:22:32Perfect.
0:22:35 > 0:22:37We certainly look the part...
0:22:40 > 0:22:43..but will we be able to act it?
0:22:43 > 0:22:45A friendly callsign has been in contact with the enemy
0:22:45 > 0:22:47across the other side of the river.
0:22:47 > 0:22:50We have been tasked to retrieve the casualties across the river
0:22:50 > 0:22:52using the infantry assault bridge
0:22:52 > 0:22:54and extract them to the casualty post.
0:22:54 > 0:22:58The team that gets their casualty to the Land Rover first wins!
0:22:58 > 0:23:00Go!
0:23:00 > 0:23:01'And we're off!'
0:23:01 > 0:23:03Right, here we go! Faster!
0:23:05 > 0:23:09This infantry assault bridge is a favourite of the British Army.
0:23:09 > 0:23:10Its brilliantly simple design
0:23:10 > 0:23:15means it can be built and dismantled quickly in virtually any conditions.
0:23:15 > 0:23:17Go, go, go, go, go!
0:23:17 > 0:23:18Cor, it's heavy!
0:23:18 > 0:23:21Come on, sweaty, put your back into it!
0:23:21 > 0:23:24SOLDIERS SHOUT My legs!
0:23:24 > 0:23:26Get the next piece! Dick! Next piece!
0:23:26 > 0:23:28All right! It's hard work, this.
0:23:31 > 0:23:33Each of these aluminium bridge sections
0:23:33 > 0:23:37is around four and a half metres long and weighs 55kg.
0:23:37 > 0:23:39I don't know if this can last, though.
0:23:39 > 0:23:41My legs are starting to give way.
0:23:41 > 0:23:42- It's neck and neck.- Come on, Dom!
0:23:42 > 0:23:44No slacking, Dominici, keep going.
0:23:44 > 0:23:46Urgh!
0:23:46 > 0:23:48I could never be in the Army.
0:23:48 > 0:23:50It's not for me. I'll stick with TV!
0:23:52 > 0:23:55The joined-up sections are pushed out across the water
0:23:55 > 0:23:57and rested on floats.
0:24:02 > 0:24:05We're halfway across and Team Dom have opened up a small lead!
0:24:05 > 0:24:08BREATHLESSLY: We've got one more piece there.
0:24:08 > 0:24:10Nice work, team.
0:24:10 > 0:24:12Final piece, final piece.
0:24:13 > 0:24:16Dom is still in front, but McCourt's no quitter!
0:24:19 > 0:24:21Good! Next piece, next piece!
0:24:22 > 0:24:26Come on, they're catching up. Come on!
0:24:26 > 0:24:29This is where we test out how strong the bridge actually is.
0:24:29 > 0:24:33The completed bridge weighs a hefty 278kg,
0:24:33 > 0:24:38which is nearly 2,000 ham sandwiches with the crusts on.
0:24:38 > 0:24:42- Shattered.- A stretcher can now be slotted on to the handrails
0:24:42 > 0:24:45to allow our casualty to be moved safely across.
0:24:46 > 0:24:49My team are first to try out a finished bridge.
0:24:49 > 0:24:51It's wobbly. Oh, it's wobbly!
0:24:51 > 0:24:53Wow! Wobbly!
0:24:53 > 0:24:54Really wobbly!
0:24:59 > 0:25:04I'm off. 'I'll have to give it everything to get back in the race.'
0:25:04 > 0:25:05- PANTING:- Right, cross.
0:25:12 > 0:25:15Three, two, one, go!
0:25:16 > 0:25:17Now for the real test.
0:25:19 > 0:25:22That really is a real soldier on the stretcher!
0:25:22 > 0:25:26- Nearly there... - Come on, McCourt! Run!
0:25:27 > 0:25:29Coming! We're coming!
0:25:32 > 0:25:34Push him!
0:25:34 > 0:25:37- I'm pushing.- Push it, push it(!)
0:25:37 > 0:25:38We're on the home straight -
0:25:38 > 0:25:41a 20-metre dash to a waiting four by four.
0:25:44 > 0:25:47And now there's clear daylight between us and Team Dick.
0:25:51 > 0:25:53We did it, everyone!
0:25:53 > 0:25:55It's victory for Team Dom!
0:25:55 > 0:25:57I'm absolutely done.
0:25:57 > 0:25:58We've lost, we've lost!
0:26:00 > 0:26:02Oopsie!
0:26:03 > 0:26:05We nearly lost the casualty!
0:26:05 > 0:26:07Tell you what, that is the fastest bit of bridge building
0:26:07 > 0:26:09I've ever seen.
0:26:09 > 0:26:12Literally from pieces of bridge to a whole bridge
0:26:12 > 0:26:14that can take the weight of about three or four people,
0:26:14 > 0:26:16all in a few minutes.
0:26:16 > 0:26:18Now, THAT was a Monster Build.
0:26:18 > 0:26:21Right, you can get up now, Jay, come on.
0:26:21 > 0:26:23Cheers.
0:26:24 > 0:26:26The bridges might be built
0:26:26 > 0:26:30but the Royal Engineers haven't finished with us quite yet.
0:26:30 > 0:26:33Congratulations, Wood. You got your casualty across first.
0:26:33 > 0:26:37McCourt, unfortunately, your team came last,
0:26:37 > 0:26:39so they will be a forfeit for you. Dom, your team is dismissed.
0:26:39 > 0:26:42- Off you go.- Everyone, all the teams are dismissed!
0:26:42 > 0:26:45McCourt, for you, it's 20 of your finest press-ups.
0:26:45 > 0:26:48- I can't do press-ups! - Let's go, stop whingeing
0:26:48 > 0:26:50- and let's get them done. Come on. - I can only do four.
0:26:50 > 0:26:54Let's go. One. All the way down! Come on, McCourt. Let's go.
0:26:54 > 0:26:57- Aargh!- Two. Come on, McCourt. I want more effort than that.
0:26:57 > 0:27:01Let's go. Come on. McCourt, my mum can do better press-ups than that!
0:27:01 > 0:27:04Ohhh... Can we go home now?
0:27:07 > 0:27:14So, thank you to our three geniuses for some truly epic bridges.
0:27:14 > 0:27:17Vitruvius, Albert, Hull, you are all Absolute Genius.
0:27:17 > 0:27:18We salute you.
0:27:18 > 0:27:21SQUAD...FALL OUT!
0:27:24 > 0:27:26My idea was the best.
0:27:26 > 0:27:27No, mine was.
0:27:27 > 0:27:30You've got to be kidding! It was mine!
0:27:46 > 0:27:47He's loving it!
0:27:47 > 0:27:49I hate this!