Mile High City

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0:00:02 > 0:00:04- Welcome to the genius world - BOTH:- ..of monster engineering.

0:00:06 > 0:00:10'Each show, we are going to introduce you to three geniuses...'

0:00:11 > 0:00:12Whoa!

0:00:12 > 0:00:16'..whose ideas have quite literally built the world.

0:00:16 > 0:00:20'We put all their epic brilliance to the test...'

0:00:20 > 0:00:22Hit it! Hit it!

0:00:22 > 0:00:24'..when we tackle our own genius monster build.'

0:00:24 > 0:00:27- Don't you dare demolish this.- Aaah!

0:00:27 > 0:00:28'Going higher...'

0:00:28 > 0:00:31Why is it swinging?

0:00:31 > 0:00:33- '..faster...' - SCREAMING

0:00:33 > 0:00:35'..and scarier.'

0:00:35 > 0:00:36Oh, no!

0:00:36 > 0:00:38'All in the name of science.'

0:00:38 > 0:00:40That is a massive piece of construction.

0:00:40 > 0:00:42What could possibly go wrong?

0:00:48 > 0:00:51'This show takes us to the dizzying heights of the skyscraper.'

0:00:51 > 0:00:53It is so hot.

0:00:53 > 0:00:57'Getting up close to the scorching material that made them possible.

0:00:59 > 0:01:01'Finding out how some genius technology made

0:01:01 > 0:01:04'tall buildings feel a whole lot smaller.'

0:01:04 > 0:01:05You missed a bit.

0:01:05 > 0:01:09'And how current skyscrapers may soon be staring up at new rivals.'

0:01:09 > 0:01:12- This is...- Absolute Genius.

0:01:53 > 0:01:55We're here in the Big Apple, New York City,

0:01:55 > 0:01:58because this show is all about a monster of engineering,

0:01:58 > 0:01:59the skyscraper.

0:01:59 > 0:02:03We're going to be looking at the genius engineers and their ideas

0:02:03 > 0:02:05that have made all of this happen.

0:02:05 > 0:02:10We'll find out how over 150 years, buildings like this have gone from

0:02:10 > 0:02:13two to three storeys to giants like those.

0:02:13 > 0:02:16And whether in the future, we'll be building mile-high cities.

0:02:19 > 0:02:22Today's towns and cities are running out of space,

0:02:22 > 0:02:26so rather than build outwards, engineers are building upwards.

0:02:26 > 0:02:29The first true skyscraper as we know it was built in

0:02:29 > 0:02:34Chicago in 1885 and had ten floors.

0:02:34 > 0:02:37The current world's tallest - the Burj Khalifa, in Dubai -

0:02:37 > 0:02:41has a whopping 163.

0:02:41 > 0:02:44But wanting to build a big isn't a new idea.

0:02:44 > 0:02:48In the early days, tall structures like the pyramids or big churches

0:02:48 > 0:02:50were all about getting attention

0:02:50 > 0:02:53with incredible jaw-dropping structures.

0:02:53 > 0:02:54Basically, showing off.

0:02:56 > 0:02:59Skyscrapers may be a very modern idea but throughout history,

0:02:59 > 0:03:01people have always wanted to build big.

0:03:01 > 0:03:02But for hundreds of years,

0:03:02 > 0:03:05this place was the tallest building in the world.

0:03:05 > 0:03:07It is Lincoln Cathedral.

0:03:09 > 0:03:13The cathedral is a pretty big and pretty impressive building.

0:03:13 > 0:03:16But for a time, it was even taller.

0:03:16 > 0:03:17It once had a huge spire on top that

0:03:17 > 0:03:19made it the world's tallest building.

0:03:25 > 0:03:28The cathedral is built out of stone,

0:03:28 > 0:03:32which meant the higher they built it, the heavier it got.

0:03:32 > 0:03:33- Come on.- Oh.

0:03:33 > 0:03:36This meant there was a limit as to how high it could go.

0:03:36 > 0:03:41Heavy stone buildings like this physically couldn't go any higher.

0:03:41 > 0:03:43The weight would cause the building to sink or topple.

0:03:43 > 0:03:45Like the leaning Tower of Pisa.

0:03:46 > 0:03:50To build bigger than this, engineers needed to find a new material.

0:03:50 > 0:03:54So, in stepped genius number one, the man who gave us steel,

0:03:54 > 0:03:55Henry Bessemer.

0:03:55 > 0:03:57Help, I'm scared of heights.

0:03:57 > 0:03:58Join the club, mate.

0:04:01 > 0:04:03The start of the Industrial Revolution in

0:04:03 > 0:04:08the 18th and 19th centuries brought with it a need to use metal.

0:04:08 > 0:04:10Engineers used materials such as iron

0:04:10 > 0:04:13to build things like machines and bridges.

0:04:14 > 0:04:18But progress brought with it an ambition to build bigger and bigger

0:04:18 > 0:04:21and iron just wasn't strong enough.

0:04:21 > 0:04:24Then in stepped Henry Bessemer with a genius plan to

0:04:24 > 0:04:29turn iron into steel on an epic scale.

0:04:32 > 0:04:35Whoa-ho-ho.

0:04:35 > 0:04:37- It is so hot!- Ah!

0:04:37 > 0:04:40Now, steel completely transformed the way we could build.

0:04:40 > 0:04:43It was cheaper, stronger and more shapeable than

0:04:43 > 0:04:45materials previously available.

0:04:45 > 0:04:47I'm going to have to move out of the way.

0:04:48 > 0:04:51And steel was a must-have for all engineers.

0:04:51 > 0:04:54It enabled them to build bridges, skyscrapers, boats, you name it.

0:04:54 > 0:04:58It's still the material behind most of our big buildings today.

0:04:58 > 0:05:00Yeah, steel was a game changer.

0:05:00 > 0:05:01It's still hot!

0:05:02 > 0:05:07We're going to meet genius helper, materials engineer Mark Miodownik.

0:05:07 > 0:05:11He's going to explain exactly how Bessemer made his steel.

0:05:12 > 0:05:14- Hi, Mark.- Hi.- Mark, how are you doing? Good to see you.- You too.

0:05:14 > 0:05:17Now, when we saw you from back there, it looked like you were

0:05:17 > 0:05:20stood underneath a massive R2-D2 statue.

0:05:20 > 0:05:22But clearly it's not. What is it?

0:05:22 > 0:05:25This is a Bessemer converter. It's very close to my heart.

0:05:25 > 0:05:27This is the first way

0:05:27 > 0:05:30that Henry Bessemer found to mass-produce steel.

0:05:30 > 0:05:33So, what was his genius? What was Bessemer's genius?

0:05:33 > 0:05:35Steel existed for thousands of years before that

0:05:35 > 0:05:38but no-one could make very much of it, only tiny little bits of it,

0:05:38 > 0:05:40and he said, "I'm going to make it on a big scale,

0:05:40 > 0:05:43"so everyone can use it." And he produced this.

0:05:43 > 0:05:46Unfortunately, this doesn't work any more, but I will show you how

0:05:46 > 0:05:48it does work. Follow me.

0:05:49 > 0:05:50Could I come too?

0:05:50 > 0:05:53So, how did Bessemer do it?

0:05:53 > 0:05:55Well, Mark is taking us to Sheffield Uni

0:05:55 > 0:05:59to recreate Bessemer's superheated chemical reaction.

0:06:00 > 0:06:03- How does it fit, sir? - Well, it's absolutely massive.

0:06:03 > 0:06:06'This is going to be hot work, so we're putting on some

0:06:06 > 0:06:09'pretty nifty heat-resistant clothes.'

0:06:10 > 0:06:12Let's go and make some steel.

0:06:12 > 0:06:14Mark, what have we got here?

0:06:14 > 0:06:18This is iron. The problem with it is it's got too much carbon inside it.

0:06:18 > 0:06:19And that makes it weak and brittle.

0:06:19 > 0:06:23Iron was used to make things like steam engines and machinery,

0:06:23 > 0:06:26but because it's brittle, it's of limited use

0:06:26 > 0:06:28in building tall structures.

0:06:28 > 0:06:32So, in stepped Bessemer's process to refine the iron.

0:06:33 > 0:06:35We've got to get the carbon out and then

0:06:35 > 0:06:37we'll be left with steel.

0:06:37 > 0:06:40- How are we going to do that? - We're going to blow oxygen through

0:06:40 > 0:06:42the liquid iron and that's going to react with the carbon,

0:06:42 > 0:06:45creating a gas that is going to go...BOOM!

0:06:45 > 0:06:46And we'll be left with steel.

0:06:46 > 0:06:50Oh, right. Listen, just to recap, melt the iron,

0:06:50 > 0:06:54pump in some oxygen, the carbon comes out and steel.

0:06:54 > 0:06:57- That's it?- Yes.- Man, can't wait. - We'll need the visors down.

0:06:57 > 0:06:59All right, then.

0:06:59 > 0:07:05To melt iron, we need a temperature of over 1,500 degrees C.

0:07:05 > 0:07:10That's hundreds of degrees hotter than lava from a volcano.

0:07:10 > 0:07:13So this is the liquid iron. We need to measure how hot it is.

0:07:13 > 0:07:15This is a fancy thermometer.

0:07:15 > 0:07:18- Can you dip this in?- Dip it in? - Just dip that tip in there.

0:07:18 > 0:07:20Have a look at the temperature at the back.

0:07:20 > 0:07:2312, 13, 14, 15, 16...

0:07:23 > 0:07:261,610 degrees Centigrade.

0:07:26 > 0:07:28That is one hot liquid metal.

0:07:28 > 0:07:32- It's so bright, you can't even look at it.- Look at that.

0:07:32 > 0:07:34'Now the iron is hot enough, let's make some steel.'

0:07:34 > 0:07:36It's like bright orange water.

0:07:36 > 0:07:38Here it comes.

0:07:41 > 0:07:44- Look how bright that is. - Is that oxygen?

0:07:44 > 0:07:45'Now for the dangerous bit.

0:07:45 > 0:07:50'Mark's about to blast the liquid iron with oxygen.

0:07:50 > 0:07:53'The oxygen is reacting with carbon in the iron.

0:07:53 > 0:07:58'It's giving off carbon dioxide and the huge sparks you can see.'

0:07:58 > 0:08:00You can feel the heat from here.

0:08:00 > 0:08:04Now, imagine this happening on an industrial scale.

0:08:04 > 0:08:06Look at it bubbling.

0:08:06 > 0:08:08OK, so you're going to pour it into that crucible.

0:08:08 > 0:08:11'With most of the carbon removed,

0:08:11 > 0:08:14'the next stage is to pour the liquid metal into a ceramic mould

0:08:14 > 0:08:17'until it sets as a solid piece of steel.'

0:08:17 > 0:08:20Look at it. It pours like water, that's the amazing thing.

0:08:20 > 0:08:23- It really does. It's like cream, isn't it?- Yeah.

0:08:23 > 0:08:26Take your visor off, look how bright that is.

0:08:26 > 0:08:28Wow! That is bright.

0:08:30 > 0:08:32So, when that cools, you get this,

0:08:32 > 0:08:33which is one we did earlier.

0:08:33 > 0:08:35A piece of steel.

0:08:35 > 0:08:38- That is heavy. I didn't expect it to be that heavy.- Is it?

0:08:38 > 0:08:39HE GROANS

0:08:39 > 0:08:41Of course, that could be turned into a skyscraper,

0:08:41 > 0:08:43a boat, a plane, a car.

0:08:43 > 0:08:45Yeah, that process changed the world.

0:08:45 > 0:08:47Bessemer, you genius.

0:08:47 > 0:08:50Oh, stop it. You're making me blush.

0:08:50 > 0:08:53Bessemer had worked out how to manufacture steel

0:08:53 > 0:08:55on a truly mammoth scale.

0:08:55 > 0:08:59And by doing so, allowed the automobile industry to take off,

0:08:59 > 0:09:01for a boom in bridge building

0:09:01 > 0:09:05and for the construction of the first skyscrapers.

0:09:06 > 0:09:09'Still to come, Dick tests his fear of heights

0:09:09 > 0:09:11'on some pretty old technology.'

0:09:11 > 0:09:13- Are you ready? - Yes. Well, no, not really.

0:09:13 > 0:09:16'Dom gets a very high window washing assignment.'

0:09:18 > 0:09:20Why is it swinging?

0:09:20 > 0:09:24'And we attempt a truly unique monster tower build

0:09:24 > 0:09:25'of our very own.'

0:09:29 > 0:09:33We're back in New York City to find out how genius engineers

0:09:33 > 0:09:37took Bessemer's steel building blocks to the next level.

0:09:37 > 0:09:41Our first genius gave us the materials we need to build big.

0:09:41 > 0:09:44But for engineers to build this skyline, they would need

0:09:44 > 0:09:45more than just a strong material.

0:09:45 > 0:09:47Before we could have skyscrapers,

0:09:47 > 0:09:49we needed a way of getting up and down them.

0:09:52 > 0:09:55Thankfully, genius number two was here to help.

0:09:55 > 0:09:58Introducing the genius of Elisha Otis.

0:09:58 > 0:10:00Going up.

0:10:00 > 0:10:04The idea of lifts - or elevators as they're called in America -

0:10:04 > 0:10:05isn't a new one.

0:10:05 > 0:10:10In Roman times, the Coliseum had lift systems pulled by humans.

0:10:12 > 0:10:13A bit dangerous.

0:10:13 > 0:10:14But early lifts were dangerous.

0:10:14 > 0:10:16I know.

0:10:16 > 0:10:18- If the rope or cable were to snap... - Oh, dear.

0:10:18 > 0:10:21..the lift platform would plummet, injuring those travelling on it.

0:10:21 > 0:10:23Told you.

0:10:23 > 0:10:26All of this changed when Elisha Otis invented the safety lift.

0:10:26 > 0:10:30An ingenious system that would catch a lift if the cable broke.

0:10:30 > 0:10:31Oh, Bravo.

0:10:31 > 0:10:34Suddenly, stairs were so yesterday.

0:10:34 > 0:10:35Jolly good. Jolly good.

0:10:35 > 0:10:39- Otis' invention was hugely important.- We'll show you.

0:10:39 > 0:10:41Yes, heads or tails?

0:10:41 > 0:10:43- Tails.- Heads.

0:10:43 > 0:10:44Stairs for you.

0:10:53 > 0:10:54How much further?

0:10:56 > 0:10:59Lifts made the idea of a skyscraper practical.

0:11:03 > 0:11:06Before lifts were invented, the only way to get to the top of

0:11:06 > 0:11:09a building was by using the stairs and that's

0:11:09 > 0:11:11not the dream, I can tell you.

0:11:11 > 0:11:13HE PANTS

0:11:16 > 0:11:18But they meant it was possible to travel up buildings

0:11:18 > 0:11:20quickly and easily.

0:11:23 > 0:11:26That's it. Five floors is my limit.

0:11:26 > 0:11:29And that's why in the olden days before lifts,

0:11:29 > 0:11:32buildings were only five or six storeys tall

0:11:32 > 0:11:33because people get tired.

0:11:33 > 0:11:35Don't blame them, really.

0:11:38 > 0:11:40The lift a meant that engineers could test the limits

0:11:40 > 0:11:44of how high buildings could go. The skyscraper was born.

0:11:47 > 0:11:50To find out how Elisha Otis convinced the world that

0:11:50 > 0:11:52lifts could be safe for us to use,

0:11:52 > 0:11:56we're heading just out of New York to the Otis lift test centre.

0:11:58 > 0:12:00We're meeting genius helper Rick Pulling.

0:12:00 > 0:12:03He's been in the lift industry for 30 years.

0:12:04 > 0:12:07- Nice lift.- Yeah.- Hi, Rick. - Rick, how are you doing?

0:12:07 > 0:12:10- Lovely to meet you.- Dom, nice to meet you.- Very good to see you.

0:12:10 > 0:12:13We want to know more about Elisha's genius. What exactly did he do?

0:12:13 > 0:12:17Well, he invented a method to stop an elevator from falling.

0:12:17 > 0:12:18He invented the safety brake.

0:12:18 > 0:12:21He worked in a bed manufacturing company

0:12:21 > 0:12:23and every time the rope would break,

0:12:23 > 0:12:26the platform with the goods would fall to the bottom

0:12:26 > 0:12:27and the beds were damaged.

0:12:27 > 0:12:30Luckily for us, Rick has an exact replica

0:12:30 > 0:12:33of Otis' very first safety platform.

0:12:33 > 0:12:37If a person was on this platform, and that rope would break,

0:12:37 > 0:12:42the tension would be released and it would push these two arms out.

0:12:45 > 0:12:48When the rope snaps, it will release two pins,

0:12:48 > 0:12:50they should lock into metal grooves at the side,

0:12:50 > 0:12:54hopefully stopping the platform from falling.

0:12:54 > 0:12:55Do you mind showing us?

0:12:55 > 0:12:58- If you'll join me.- Ah, yes. - No, he'd love to join you.

0:12:58 > 0:13:00No, surely you need someone heavier to test

0:13:00 > 0:13:02- out the weight load, don't you?- Come on.

0:13:02 > 0:13:03I think it's you, my friend.

0:13:03 > 0:13:05'Well, as Dick's on the platform,

0:13:05 > 0:13:08'I think I'll do the honours and cut the rope.'

0:13:08 > 0:13:12- Right, up we go then, Rick. - I'm ready. Raise the platform.

0:13:13 > 0:13:16It's not that high.

0:13:16 > 0:13:19'It may not be high, but I'm still not 100% sure about this.'

0:13:22 > 0:13:24- Put on our glasses.- They're not going to help us, are they?

0:13:24 > 0:13:26- Are you ready?- Yes.

0:13:26 > 0:13:28- Well, no, not really. - Well, Dom, cut the rope.

0:13:30 > 0:13:33And then we'll find out whether 150-year-old plans

0:13:33 > 0:13:36still stand the test of time.

0:13:36 > 0:13:38If that did fall, it would hurt.

0:13:38 > 0:13:41Yeah. It wouldn't be very good on your back, would it?

0:13:41 > 0:13:44'I'm putting a lot of trust into some pretty old plans.

0:13:44 > 0:13:48'Especially when the only thing holding me up is this bit of rope.'

0:13:48 > 0:13:52- All right, Dom. On the count of three.- My heart's beating.

0:13:52 > 0:13:55Three, two, one... Cut the rope.

0:13:57 > 0:14:01HE SHRIEKS

0:14:01 > 0:14:04THEY LAUGH

0:14:04 > 0:14:06HE LAUGHS

0:14:06 > 0:14:07- There we are.- It works.

0:14:09 > 0:14:13'So, just moments after the rope was cut, the pins engaged,

0:14:13 > 0:14:16'which meant the platform fell just a few centimetres.

0:14:16 > 0:14:19'I don't know what I was worrying about.'

0:14:19 > 0:14:21Well, Rick, thank you very much indeed.

0:14:21 > 0:14:22- It's been brilliant. - Dom, it was great.

0:14:22 > 0:14:25- Cheers, Rick.- Richard, a pleasure, thank you.

0:14:25 > 0:14:27It was my idea. Thank me.

0:14:27 > 0:14:31By giving us safe lifts, Otis enabled the construction of

0:14:31 > 0:14:33buildings to go higher than ever.

0:14:33 > 0:14:38The skyscraper was born and the skylines of our cities

0:14:38 > 0:14:39were changed forever.

0:14:39 > 0:14:42Skyscraper dreams could at last become a reality,

0:14:42 > 0:14:46but not all tall buildings are created equal.

0:14:46 > 0:14:52It's time for some random genius-nessss.

0:14:54 > 0:14:56In Bangkok, some brainy so-and-so

0:14:56 > 0:14:59decided to mix his love for big buildings

0:14:59 > 0:15:02with his love for elephants. And this is the outcome.

0:15:02 > 0:15:05I'd rather have a room in the trunk than in the bottom,

0:15:05 > 0:15:06thank you very much.

0:15:06 > 0:15:10British architects also love their weird-shaped towers.

0:15:10 > 0:15:13In London, there's one in the shape of a walkie-talkie,

0:15:13 > 0:15:14a gherkin,

0:15:14 > 0:15:16and a cheese grater.

0:15:16 > 0:15:19But in Spain, they're still building this thing,

0:15:19 > 0:15:21the geniusly squiggly Sagrada Familia.

0:15:21 > 0:15:24Construction started in 1882

0:15:24 > 0:15:28and won't finish for at least another decade. Get a move on!

0:15:30 > 0:15:32We are here at the top of One World Trade Center,

0:15:32 > 0:15:35the tallest building in New York and America.

0:15:35 > 0:15:37With an amazing view.

0:15:37 > 0:15:40You can see the whole of New York. It is breathtaking. It's amazing.

0:15:40 > 0:15:43- It's terrifying.- It is terrifying. And for a very good reason.

0:15:43 > 0:15:47It's because right now, we are one third of a mile high

0:15:47 > 0:15:50- in the sky. - And our next genius not only

0:15:50 > 0:15:53inspired this building, he came up with a plan to go even higher.

0:15:53 > 0:15:55Surely that's not possible. Maybe it is.

0:15:55 > 0:15:58All thanks to one genius architect, Fazlur Khan.

0:15:58 > 0:16:00Higher and higher, baby.

0:16:00 > 0:16:04Sometimes referred to as the Einstein of structural engineering,

0:16:04 > 0:16:09American architect Fazlur Khan designed skyscrapers for a living.

0:16:09 > 0:16:13He created the Hancock and Sears Towers in Chicago.

0:16:13 > 0:16:14And in making them

0:16:14 > 0:16:18created an entirely new way of building skyscrapers.

0:16:18 > 0:16:21Khan took the normal way of building a skyscraper

0:16:21 > 0:16:23and turned it inside out.

0:16:23 > 0:16:27To find out more about Khan's genius idea, we've left New York

0:16:27 > 0:16:29and headed back to London

0:16:29 > 0:16:32to see a building built using his principles.

0:16:33 > 0:16:36We're going to meet genius helper Roma Agrawal.

0:16:36 > 0:16:39She designs skyscrapers for a living.

0:16:39 > 0:16:42- Hi, Roma.- Hi, Roma.- Lovely to meet you.- Lovely to meet you as well.

0:16:42 > 0:16:43And what a view. Look at this.

0:16:43 > 0:16:45So, Fazlur Khan, what did he do?

0:16:45 > 0:16:49So, Fazlur Khan came up with a totally different way

0:16:49 > 0:16:51of building skyscrapers. Before him,

0:16:51 > 0:16:54the skyscrapers had a spine, a bit like our body,

0:16:54 > 0:16:56which kept them strong.

0:16:56 > 0:16:58So the main construction that held it all together

0:16:58 > 0:17:01- went right in the middle?- That's it. - And then what did Fazlur Khan do?

0:17:01 > 0:17:04Fazlur Khan took that from the inside of the building

0:17:04 > 0:17:07and spread it all around the outside.

0:17:07 > 0:17:12- So it's a bit like a turtle shell, like an exoskeleton, perhaps.- Yeah.

0:17:12 > 0:17:15The old method of construction was to make a heavy

0:17:15 > 0:17:17steel frame in the middle of the building.

0:17:17 > 0:17:19Shall we go downstairs then, have a look at this turtle shell?

0:17:19 > 0:17:22Well, I'm not going to make things that easy for you.

0:17:22 > 0:17:25- I've got something special organised.- Special.

0:17:25 > 0:17:29Don't like special. Special is not good. Go on, then.

0:17:29 > 0:17:32'Roma doesn't seem to be taking us downstairs.

0:17:32 > 0:17:34'I'm getting a bad feeling about this.

0:17:34 > 0:17:36'What she got in mind for us?'

0:17:36 > 0:17:39- So...- Yes.- This is the surprise.

0:17:39 > 0:17:43Well, the plan is that one of you is going to get into this cradle

0:17:43 > 0:17:46and that way, you'll be able to dangle outside the building

0:17:46 > 0:17:50and see Fazlur Khan's genius work up-close and personal.

0:17:50 > 0:17:53So one of you is going to get into there,

0:17:53 > 0:17:56- lower yourselves down the outside of the building...- Yeah.

0:17:56 > 0:17:57And clean some windows.

0:17:57 > 0:17:59You clean the windows from the inside.

0:17:59 > 0:18:02Get rid of the grubby fingerprints and I'll be here with Andrew,

0:18:02 > 0:18:04having a better time. All right?

0:18:04 > 0:18:07'Yeah, I think I've been stitched up here.'

0:18:13 > 0:18:14Done.

0:18:14 > 0:18:18METAL CREAKING

0:18:18 > 0:18:20Why is it swinging?

0:18:22 > 0:18:27'Yeah, I've definitely picked the short straw here.'

0:18:27 > 0:18:29Stop making it wobble.

0:18:32 > 0:18:35Bye-bye, everybody. Bye-bye.

0:18:37 > 0:18:40That's it, nice and clean, please. You missed a bit.

0:18:46 > 0:18:49Roma, why am I doing this anyway? What's the point?

0:18:49 > 0:18:51'Roma is going to tell you.'

0:18:51 > 0:18:54The real reason is because you can see really clearly

0:18:54 > 0:18:57Fazlur Khan's genius,

0:18:57 > 0:18:59so those big huge bits of steel

0:18:59 > 0:19:02in front of you are the exoskeleton that he designed

0:19:02 > 0:19:04to make really tall buildings.

0:19:04 > 0:19:07Ah, I see. But I could see them from the inside.

0:19:10 > 0:19:13- It does look a bit streaky, I'm afraid.- Roger.

0:19:14 > 0:19:18- Right.- So these massive pieces of steel form the

0:19:18 > 0:19:20big exoskeleton around this building,

0:19:20 > 0:19:23which helps keep it nice and strong.

0:19:23 > 0:19:26'The exoskeleton design meant less steel would be needed

0:19:26 > 0:19:29'and buildings could be built lighter than was possible before.'

0:19:29 > 0:19:30Why is it so important?

0:19:30 > 0:19:34So, this system actually makes it much, much easier

0:19:34 > 0:19:36to go really tall with skyscrapers.

0:19:36 > 0:19:39- How tall?- Well, the Burj Khalifa in Dubai,

0:19:39 > 0:19:42which is the tallest building, is more than 800 metres tall.

0:19:42 > 0:19:44- Wow!- But I mean, you could go as tall as

0:19:44 > 0:19:46you wanted, really, in theory.

0:19:46 > 0:19:48The dream of a mile-high city could become reality?

0:19:48 > 0:19:51- It could. It absolutely could. - All because of Fazlur Khan.

0:19:51 > 0:19:52Yes, it could.

0:19:52 > 0:19:54Aim high, baby.

0:19:54 > 0:19:57Khan's amazing designs allowed for new shapes

0:19:57 > 0:19:59of skyscrapers to be made.

0:19:59 > 0:20:02Suddenly, far less steel was needed to build big

0:20:02 > 0:20:07and it meant that for engineers, the sky was now literally the limit.

0:20:08 > 0:20:10'So far, we've learnt how our first

0:20:10 > 0:20:13'genius gave us the material we needed to build big.'

0:20:13 > 0:20:15You can feel the heat from here.

0:20:16 > 0:20:19'How our second genius made it a lot easier to get

0:20:19 > 0:20:20'to the top of big buildings.'

0:20:20 > 0:20:22Cut the rope.

0:20:25 > 0:20:30'And how Khan's exoskeleton designs have pushed super tall buildings

0:20:30 > 0:20:31'to even greater heights.'

0:20:31 > 0:20:33Why is it swinging?

0:20:38 > 0:20:40Thanks to our three geniuses, super tall buildings

0:20:40 > 0:20:43have gone from being a dream to a skyscraping reality.

0:20:43 > 0:20:46And they are absolutely everywhere.

0:20:46 > 0:20:50Today's monster build challenge is to build our very own skyscraper.

0:20:50 > 0:20:54Out of a household object that I can guarantee has never been

0:20:54 > 0:20:56used to build a skyscraper before.

0:20:59 > 0:21:02Here's the plan. Our challenge is to create

0:21:02 > 0:21:05a scaled-down version of the world's tallest building,

0:21:05 > 0:21:07the Burj Khalifa in Dubai.

0:21:09 > 0:21:12Except our Burj will be made entirely out of drinking straws.

0:21:14 > 0:21:17Flimsy, bendy straws. Nothing else.

0:21:19 > 0:21:22It'll need to be at least five metres high

0:21:22 > 0:21:25and sturdy enough to support its own weight

0:21:25 > 0:21:29and then strong enough to be battered by huge wind machines.

0:21:30 > 0:21:32I think we're going to need some help.

0:21:35 > 0:21:37When structures get us scratching our heads,

0:21:37 > 0:21:41thankfully we have superstar engineer Yewande

0:21:41 > 0:21:42to call on for help.

0:21:42 > 0:21:44Aaaaah!

0:21:44 > 0:21:47- Yewande.- Hi.- We need your help. - OK.- Big-time.

0:21:47 > 0:21:49All right, you've come to the right place.

0:21:49 > 0:21:52We're trying to recreate the world's tallest building...

0:21:52 > 0:21:53- OK.- ..the Burj Khalifa.- Oh, good.

0:21:53 > 0:21:56- But we want to build it out of straws.- Out of straws?

0:21:56 > 0:21:57How do we do that?

0:21:57 > 0:21:59- Cos if you are putting straws one on top of another...- Yes.

0:21:59 > 0:22:01- ..five metres high...- OK.

0:22:01 > 0:22:03- ..it's just gone to fall over, isn't it?- Exactly right.

0:22:03 > 0:22:08We already know Fazlur Khan's amazing idea of actually putting

0:22:08 > 0:22:12the support mechanism of the building round the outside.

0:22:12 > 0:22:15Just like that. But he had another idea.

0:22:15 > 0:22:20Right, so his idea was pretty much bundling up structures together.

0:22:20 > 0:22:22Right, so what you're saying is that a straw on its own

0:22:22 > 0:22:25is only as strong as a straw, whereas if you bundle it together

0:22:25 > 0:22:27with ten, then you're going to make it

0:22:27 > 0:22:29more than ten times stronger than if it's on its own.

0:22:29 > 0:22:31And that makes sense, doesn't it?

0:22:31 > 0:22:35And this genius is behind lots of the world's tallest buildings today.

0:22:35 > 0:22:38Like the Burj Khalifa.

0:22:38 > 0:22:41- Yes, we're going to need some help. - We need a bundle expert.

0:22:41 > 0:22:43- Yes, yes.- Good.

0:22:43 > 0:22:44- Morning.- Morning.

0:22:44 > 0:22:47'Yewande is taking us to a workshop where they are more than used to

0:22:47 > 0:22:50'making all kinds of unusual structures.'

0:22:50 > 0:22:52- Look. Straws.- We have the straws.

0:22:52 > 0:22:54These are...

0:22:54 > 0:22:55Gosh. OK, guys.

0:22:55 > 0:22:58- Another bag of straws. - Look at the straws we've got.

0:22:58 > 0:22:59Now what?

0:22:59 > 0:23:02'So, we've got the straws but how do we make the structure?'

0:23:02 > 0:23:04Right, let's get a production line going.

0:23:04 > 0:23:05I'll pick up the straws.

0:23:05 > 0:23:08Have we not got people that can do this for us?

0:23:08 > 0:23:11Put that down. Pick up some straws.

0:23:11 > 0:23:14- Yes.- And see if we can get some consistency.

0:23:14 > 0:23:17'Somehow, we need to turn these thousands of straws

0:23:17 > 0:23:21'into the hundreds of bundles that will make our superstructure.'

0:23:21 > 0:23:23- Oh, you've got one.- Kind of.

0:23:23 > 0:23:26One down, about 299 to go.

0:23:26 > 0:23:28'At this rate, it's going to take forever.

0:23:28 > 0:23:30'It's all hands on deck.'

0:23:30 > 0:23:34- We've done most...- Yeah. - ..most...- Tiny...

0:23:34 > 0:23:37..most of the work. Just a bit for you to finish off now,

0:23:37 > 0:23:39- is that all right?- Yes, that's fine.

0:23:39 > 0:23:41'You little fibber.

0:23:43 > 0:23:46'Much bundling later and our straw-building helpers

0:23:46 > 0:23:48'have made quite a bit of progress.'

0:23:50 > 0:23:54- How many straws do we have here? - About 17,500.- What?!

0:23:54 > 0:23:56But where do we start? How do we put it together?

0:23:56 > 0:23:59Do you know what? I'm thinking we start right

0:23:59 > 0:24:00- in the middle.- In the middle?- Yes.

0:24:00 > 0:24:02- Tallest bit first. - The centre columns, yes.

0:24:02 > 0:24:04How about that?

0:24:04 > 0:24:06'Let's get started.'

0:24:06 > 0:24:08It's looking a bit floppy at the top at the moment. How are we going

0:24:08 > 0:24:11- to connect it together? More tape? - I think more tape.

0:24:11 > 0:24:13Gosh!

0:24:13 > 0:24:15'This isn't going well.'

0:24:15 > 0:24:16Hold on a minute, that's my leg.

0:24:16 > 0:24:18THEY LAUGH

0:24:18 > 0:24:19Quit messing around.

0:24:19 > 0:24:21Right, now what?

0:24:21 > 0:24:23'We need some height assistance.'

0:24:23 > 0:24:25- That's what we need.- Perfect.

0:24:25 > 0:24:27You need more than that.

0:24:27 > 0:24:29How do I...?

0:24:29 > 0:24:32- We've lost one here.- Ah!

0:24:32 > 0:24:33Breakage.

0:24:33 > 0:24:35You're making a mockery of my work.

0:24:42 > 0:24:45Oh, dear. Look, it's all snapped here in the middle.

0:24:45 > 0:24:46- It does, yeah.- Too much weight.

0:24:46 > 0:24:48He broke it.

0:24:48 > 0:24:50Now, now, boys. No arguing.

0:24:50 > 0:24:53'The columns are not strong enough to stand on their own.

0:24:55 > 0:24:58'So we're going to have to add more bundles

0:24:58 > 0:25:00'or this could be a floppy failure.

0:25:00 > 0:25:02'OK, let's get ready for round two.'

0:25:02 > 0:25:05This time, get it level on the bottom.

0:25:05 > 0:25:07I'm not uncutting anything else again.

0:25:09 > 0:25:11- Good.- Looks pretty solid, that one.

0:25:11 > 0:25:15Do you know what? Let's stand it. Let see if it actually stands up.

0:25:15 > 0:25:17- Yeah, let's try.- Are you ready?

0:25:17 > 0:25:20- Oh, yeah. Look at that. - Look at that.

0:25:20 > 0:25:22OK, well, we've got it standing up, so now what

0:25:22 > 0:25:24we're going to do is put it against the fan.

0:25:24 > 0:25:27- Oh, yes.- Yeah.- All right? - That would be a real test.

0:25:27 > 0:25:30'Our model is standing up at last but if this were a real building,

0:25:30 > 0:25:33'it would have high winds to contend with.

0:25:33 > 0:25:35'Where is our number one fan?'

0:25:35 > 0:25:38- Turn on the fan.- Full blast.

0:25:38 > 0:25:39Here it goes.

0:25:40 > 0:25:42Ahhh!

0:25:42 > 0:25:44- Yewande?- Yes.- It didn't work.

0:25:44 > 0:25:47- It fell over.- Yes, it did. - What can we do?

0:25:47 > 0:25:50- Right, so, just like a tree... - Yes.- ..we need to build a

0:25:50 > 0:25:53bigger base, right? So a tree has got roots that

0:25:53 > 0:25:56go out quite wide out, right? To get a nice firm base.

0:25:56 > 0:25:58And that's what we need to do.

0:25:58 > 0:26:00More bundles, please.

0:26:00 > 0:26:02It was never going to work.

0:26:02 > 0:26:03I'll go under.

0:26:03 > 0:26:06Right. Another one here, do you think? Two more bits.

0:26:06 > 0:26:08Look at that.

0:26:08 > 0:26:10- Some tape on this side, please. - A bit more.

0:26:12 > 0:26:15- There you are, solid.- It is.

0:26:15 > 0:26:19- Great. Yeah.- Good job. But final touch, the three genius flag.

0:26:19 > 0:26:21- Oh, yes.- All right?

0:26:21 > 0:26:25- That can go about there.- There. - Perfect.- Right. Let's admire it.

0:26:27 > 0:26:29- Look at that.- It looks good. Very good.

0:26:29 > 0:26:31'Standing at five metres tall,

0:26:31 > 0:26:34'our skyscraper is built from 20,000 straws,

0:26:34 > 0:26:38'but will it stand up to the wind machine?'

0:26:38 > 0:26:41Now, without the finishing touches, last time, that fell over with

0:26:41 > 0:26:45the force of the fan. Do you think this will stand the test of time,

0:26:45 > 0:26:46now we've reinforced it?

0:26:46 > 0:26:50We've got a bigger base, so it stands a chance, right?

0:26:50 > 0:26:52Yes. Turn on the fan.

0:26:54 > 0:26:56Fazlur Khan, are you an absolute genius?

0:26:58 > 0:27:03Oh, yeah. Look at that! Hey?

0:27:03 > 0:27:05Nothing. Solid.

0:27:05 > 0:27:06What?!

0:27:07 > 0:27:10'All right, then, not the most elegant of structures,

0:27:10 > 0:27:13'but we did it. We erected probably the

0:27:13 > 0:27:15'world's tallest tower of drinking straws.'

0:27:15 > 0:27:17Oh, yeah. Look at that.

0:27:19 > 0:27:22'On this show, we've learned how our three geniuses gave us

0:27:22 > 0:27:26'the material and the designs to build soaring skyscrapers.

0:27:27 > 0:27:30'Plus the means of getting up and down them.

0:27:30 > 0:27:34'City skylines is across the world are becoming super-sized.'

0:27:34 > 0:27:38All thanks to these three - Bessemer, Otis, and Khan,

0:27:38 > 0:27:40you're all absolute genius.

0:27:56 > 0:27:58He's loving it.

0:27:58 > 0:27:59I hate it.