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00:00Who is the best in the world at engineering?
00:28Well, from steam engines to jet engines, from the train to the hovercraft, the list of British inventions is second to none.
00:36Look closely, and you'll find that the British were behind almost every big advance that shaped the modern world.
00:42In this series, some Premier League eggheads have steered me towards their favourite icon, which they feel best reflect our national engineering genius.
00:51My search for the best of British engineering has taken me the length and breadth of the country, and on my journey I've seen some pretty amazing stuff.
01:01But there's something about a bridge which is a bit special.
01:09These are among the biggest man-made structures in existence.
01:14And it's another branch of engineering in which Britain has led the world.
01:20So which ones have made it to our best of Britishness?
01:28I've come to London to see its most famous symbol, probably the most distinctive and celebrated river crossing in the world, Tower Bridge.
01:42This is the most fairy-tale bridge in the world.
01:45It looks like two tall castles sitting on neighbouring islands.
01:49The handsome prince from one falls in love with the beautiful princess from the other, and his ugly engineer uncle designs the drawbridges to meet in the middle.
02:00Tower Bridge was the answer to an apparently intractable problem.
02:05How do you get the horses and carriages across the river while still letting your tall ships into the world's busiest port?
02:12The ingenious solution was a massive bascule, or drawbridge, done up in Neo-Gothic to blend in with the Tower of London.
02:20When it was built in 1884, Tower Bridge was one of the engineering marvels of the world.
02:25No wonder the Americans wanted to buy it.
02:29First stop is the old control room, which sits on the south pier.
02:34Wow, look at this. It's this raised lower.
02:38I wonder what that does.
02:40Now today we're going to witness a very special event.
02:43The bridge is going to be opened fully.
02:45That happens very rarely nowadays.
02:47And they're doing this to let through a monster of a ship, a naval battleship, HMS Somerset.
02:53And all that's going to be done from the new control tower, which is a much more high-tech operation.
02:57And who's going to open the bridge?
02:59Me!
03:01But before they'll let me get my sweaty hands on the controls, I've been told I need a crash course on how Tower Bridge works.
03:08So the bridge master, Eric Suthers, is taking me into what looks like Jack the Ripper's wine cellar.
03:15Where are you taking me, Eric? It's getting spooky!
03:18This is our bascal chamber, Rory.
03:21Eric, you've brought me to the very bowels of the earth.
03:24Not quite the bowels of the earth, Rory. We're just below the water level.
03:27We're actually below the river now?
03:29Just about, yes.
03:30So where is the level of the river?
03:32Halfway up that line there.
03:34Good lord. So if we go down these steps, we're actually walking into the river.
03:38We are underwater, yes.
03:39This is an amazing place, this. It's called the bascal chamber, is it?
03:43This is the bascal chamber.
03:45So what I'm looking at now is actually the underneath of the road.
03:48We're underneath the road.
03:50So this bit is the bit that comes down, the bit of the sea soil that comes down.
03:54So how far does it come down? Because we're standing in a very, very dangerous position, it strikes me.
03:59If we did a full lift, it would come back just short of the wall.
04:03Can you actually stand here when the bridge comes down?
04:05You can do.
04:07And it will just about touch your shoulder as it stops.
04:11And what weight are we talking about that has to move?
04:13The bascal itself is 1,100 tonnes.
04:161,100, that's heavier than me.
04:22When Tower Bridge opens, this is the bit you never get to see.
04:26Down here you realise what a massive piece of engineering this is.
04:30It's like being inside a gigantic potato masher.
04:33And how did it work? Well, Tower Bridge went up in the age of the steam engine.
04:37So naturally, the engineers made it a kind of cross between a bridge and a train.
04:43Here we are in the engine room.
04:45Now, what's happened so far is fires have heated up water to make steam.
04:48That steam has been used to pump water into accumulators,
04:52and the weight of which, at the crucial moment, will be released to drive these pistons,
04:56which drive these wheels, which, as you can see, have a pinion on them.
04:59These pinions attach to other pinions and other crankshafts,
05:01and eventually it all engages with the rack on the actual bridge bascule itself,
05:06forcing it down and the bridge up.
05:08You see? Simple. Very simple. Deceptively simple.
05:12I mean, you think it's going to be really complicated,
05:14but it actually turns out to be very simple indeed.
05:16Don't know why I didn't think of it myself.
05:22Now for the fun bit, opening the bridge.
05:26Right, we're stopping the road traffic now by shutting the traffic lights.
05:29Southwest roadway, please. Southwest roadway, Brian.
05:31We're stopping the traffic. We're stopping the traffic.
05:33We've now got to get rid of the public.
05:35How are we getting rid of the public, Charlie?
05:37Well, the siren helped.
05:38And you must have got a rifle.
05:40No, no, no. Last resort rifle.
05:42And the gates. Are the gates shutting?
05:44Yes, we've just shut the last...
05:45Shutting the gates now, and the huge warship is approaching us.
05:49Now, how can I help you out here, Charlie?
05:51I want to be as much as possible...
05:54He's struggling with that gate.
05:56We've got a problem on the southwest gate.
05:58Southwest gate.
05:59We just have to stand in the middle of the road.
06:02The southwest gate is jammed.
06:06HMS Somerset. HMS Somerset.
06:08Can you just ease up, please?
06:10It's moving at some speed.
06:12We've asked it to slow down, please.
06:14Mr. McGrath is not ready yet.
06:17Gates are shut.
06:18It's a very, very exciting day.
06:20It is very tense.
06:22The public are clear, I think, Charlie.
06:24A few odd stragglers, but who cares about them?
06:26That warship was moving at some speed around the corner, wasn't it?
06:29That was a little bit discerning.
06:30It was indeed, yeah.
06:33So what we've done now, we've unlocked the pawls, which is the main locking device.
06:35Yes.
06:36Pawls are unlocked.
06:38And now we're withdrawing the nose bolts.
06:40That's the thing that holds the road together in the middle, isn't it?
06:42That's right, and four steel pins.
06:43Nose bolts retract.
06:45Okay, you can see it all happening on the screen.
06:47Yes, yes.
06:48I want you to grab hold of this lever.
06:49When I tell you to do so, just pull the lever fully back.
06:51Once you've got it back, keep it back.
06:53This is the most power I've ever had.
06:55Is that right?
06:56Yes, pull it back, and away we go.
06:57I am now opening Tower Bridge!
07:00Look at this!
07:02That's me.
07:03That is me, don't it?
07:04I've shifted about 2,000 tonnes of material there in one go.
07:08I'm used to that, aren't I?
07:10Goes up quite quickly, doesn't it?
07:11Yes, about 90 seconds from the ground.
07:13This is very exciting.
07:14I hope the Royal Navy appreciate what I'm doing.
07:16I hope so, too.
07:17It's obvious he's seen who's operating the bridge,
07:19and he's decided to slow down a bit, yeah.
07:21Private, can I just stop there, please, Rory?
07:23Just relax.
07:24Relax.
07:25Now, what's the etiquette about waving at the ships as they go past?
07:28There's more chance of you waving to her than her waving to you.
07:33I hope you notice how smooth that was.
07:34It's probably one of the smoothest bridge openings I've certainly ever appreciated.
07:39I wonder if they realise it was me who opened the bridge,
07:41that quirky individual style of mine.
07:46Now, do we salute this or will they think we're taking a risk?
07:49Yes, it is him off the telly.
07:51They are waving to someone.
07:54Yes, it was me.
07:58But now I'd like to show you how to close the bridge.
08:01Are we ready, Charlie?
08:02We're ready.
08:03OK, watch this.
08:05Nothing's happened.
08:07Nothing's happened.
08:09I think you're right.
08:11Oh, it is happening, yeah.
08:12Now we've got to put another 20p in and see if that'll help.
08:16This is wonderful.
08:17What power, what control I have.
08:21It's a bit slower going down, isn't it?
08:23I love the way it meets in the middle.
08:25I don't know why that should surprise me.
08:30Standby bridge crew, about to open road gates.
08:32Traffic, please wait for a green signal before moving off.
08:37Tower Bridge manages to pass itself off as a stone bridge, but it's not.
08:41It's really an iron bridge clad in stone.
08:43And that's the secret.
08:47Iron revolutionised bridge engineering.
08:49And guess what?
08:50It was us Brits what done it.
08:52As I'm about to discover as my arduous journey continues.
08:56What's the best pub around here then?
08:59The New Inn?
09:01Funny old things, Rivers.
09:02The arteries of economic life since the earliest days of human civilisation.
09:06And yet a complete pain to get across.
09:10When Isambard Kingdom Brunel and his chums decided to roll up their sleeves and build a modern world,
09:15high up on their to-do list was Better Bridges.
09:19To see how they did it, I've come to lovely Shropshire.
09:24Now listen.
09:25Have you got too much money?
09:27Would you like to get rid of some?
09:29Well, forget fast women and slow horses.
09:32Build a bridge.
09:33You will lose money.
09:34It's a cast-iron certainty.
09:36It's certainly true of this cast-iron bridge we're about to meet.
09:41This bridge was built in the days when engineers were called Iron Masters.
09:45And Iron Masters were called things like Abraham Darby III.
09:49The Abraham Darby III of whom I speak was a very rich Iron Master
09:53and decided to blow his pile on the best bridge in the world.
09:58And this is what Darby spent his money on.
10:01The biggest and most expensive Meccano set ever made.
10:07The Iron Bridge in Colebrookdale is all the more amazing when you realise when it was built.
10:13In 1777 it was fashionable for men to wear big white wigs.
10:17George III was still sensible and Mozart had only just learned the piano.
10:22Up till then bridges were made of stone.
10:25Nothing like this had ever been seen.
10:27It was like someone today building a house out of toothpaste.
10:31This was an engineering wonder.
10:33The world's very first Iron Bridge.
10:36Our hero Abraham III had a reputation with boilers.
10:40He'd be making them for the newfangled steam engines
10:43that were powering the emerging industrial revolution.
10:49Abraham turned from boilers to bridge building
10:52not because they needed a bridge in Colebrookdale
10:54but because he thought it would be a fantastic advert
10:57for a rather clever invention of Abraham Darby I.
11:01A cheap way of making cast iron.
11:04In 1709 Darby I discovered that if you mix up some iron ore, manganese and limestone
11:09shove it in an oven and heat it up to 1200 degrees centigrade
11:12you get this really useful runny stuff called molten iron.
11:16Wow, look at this.
11:18Why was this so useful?
11:20Well, for centuries if you needed something made of metal
11:22you had to pop round to the local blacksmith
11:24who would hammer some hot chunk of the stuff roughly into shape.
11:29But with Darby's new method you could pour liquid iron into moulds.
11:33This means you can quickly create elaborate shapes
11:36and reproduce them perfectly again and again.
11:40Goodbye blacksmith, hello the mass production
11:43of hundreds and thousands of identical metal parts.
11:46Got good gloves on.
11:48They're not woolen obviously.
11:52Darby III realised that cast iron was going to change the world forever
11:56but how could he prove it?
11:58Well, no one had ever considered building anything as daft as a metal bridge.
12:03So that's what Darby decided to do
12:05across the River Severn using 1737 pieces of cast iron.
12:12Now how about this, just one of these supporting arches
12:15weighs an incredible five and a quarter tonnes.
12:18That's heavy, that's five minis.
12:20That's 56 times heavier than me.
12:22Imagine that, 56 me's.
12:26Darby took a chance building the bridge out of cast iron
12:29but the shape of his bridge followed a tried and tested principle.
12:33To see what that was I'm off to meet Claire Barrett, our series engineer.
12:37Now iron bridge in Calbrookdale,
12:39very different from a suspension bridge, very different from a cantilever.
12:42It's an arch.
12:43It's perfectly simple and a very, very good bridge.
12:46But why is an arch so strong?
12:47That's what I understand.
12:48They look very flimsy to me
12:49and yet they're used all over the world in all times.
12:52Flimsy, I think I prefer the word elegant.
12:54Shall we just try and build this one?
12:55So we're building iron bridge in pieces.
12:59When you build an arch you have to have a load of scaffolding underneath.
13:03For iron bridge they would have had masses of scaffolding in the middle
13:06but we'll just use our hands here and the pair of us.
13:10Now that was very simple.
13:12So the arch just carries those horizontal and vertical forces
13:16all the way down to the foundations.
13:18I see, and this presumably, am I right, is the principle of the dome?
13:23Yes, yes.
13:24And it comes from all?
13:25Spin an arch in 360 degrees and you've got a dome.
13:28You can stand on that now.
13:29Can I?
13:30Go on.
13:31Now this I don't believe.
13:32Just in case.
13:33Okay, I'm here to catch you.
13:37Okay, move away.
13:39Look at that.
13:40I would never have thought that would support all 12 stone 3 of me.
13:4512 stone 3?
13:46Shut up.
13:47Now I'm very careful to keep my weight vertical.
13:50I'm sure if I started moving around we might have problems.
13:52Yeah, well we haven't got much connecting this one.
13:55Right, so presumably if a load came from the side that would happen.
14:00Yeah.
14:01Very good.
14:05So Clare thinks you need lots of scaffolding to build an arched bridge
14:09but Darby was even cleverer than Clare.
14:11How do we know?
14:12Well, 8 years ago in a Swedish museum buried under a pile of ABBA records
14:16and musty meatballs they discovered a watercolour
14:19showing Darby's iron bridge under construction.
14:22And what do you know? No scaffolding.
14:25Just a funny kind of improvised crane.
14:28But can you trust a watercolourist?
14:31David De Haan from the Iron Bridge Gorge Museum decided to find out for himself.
14:36David, this is fantastic. What is it?
14:39It's a half-size model of how we think the bridge was built.
14:44It gives us four points where you could attach block and tackle,
14:49raise things from boats directly underneath it
14:52and you could tilt this sort of goalpost thing over and do the next one.
14:57So it was useful, you actually did learn how they did it by building this.
15:00It's totally workable.
15:01And you've got this brilliant half-size River Severn here built.
15:04Half-size River Severn.
15:05Half-size River Severn is a river three and a half, isn't it?
15:09Nearly.
15:11Darby's bridge cost £6,000, which personally I think is pretty reasonable,
15:16but was enough in 1771 to push the Iron Master to the brink of financial ruin.
15:21But what a way to blow six grand.
15:23Here's a difficult question for you, Dave.
15:25If Abraham III were to come back here today, what do you think he'd think?
15:29He'd think, bloody hell, my bridge is still there.
15:31I think he'd be very pleased about the bridge.
15:33I think he'd be sorry to see that the industry's gone,
15:37that it's strange, it's become country.
15:40All these yuppies.
15:42But very proud that this is here. Fantastic.
15:46His advert still exists, like a big poster.
15:49Yes, AD was here.
15:54Darby's legacy is more than Iron Bridge.
15:57Thanks to him, a new era had dawned.
16:00Engineers could now imagine building bridges spanning huge distances.
16:04They had the material.
16:06If only they could think of a revolutionary design to go with it.
16:10Hugh Thomas Telford.
16:13The White Knight said to Alice,
16:15I heard him then, for I had just completed my design
16:20to keep the Menai Bridge from rust by boiling it in wine.
16:25Now, you may not have heard of the Menai Bridge,
16:27but in 1872 it was famous enough to feature in Lewis Carroll's Through the Looking Glass.
16:32And if you look on the back of the new pound coin, you'll see it there too.
16:40If Darby's Iron Bridge showed the world what could be done with cast iron,
16:43the revolutionary Menai Straits Bridge showed it a radically new way to build bridges.
16:49This is the first time anyone had tried to suspend a big road from towers using metal cable.
16:54A suspension bridge to you.
16:57The bold new design meant the bridge could span 177 metres of water,
17:01making it, in its day, the biggest bridge span in the world.
17:07The bridge was the solution to a potentially fatal problem.
17:10Before 1826, if you wanted to catch the Irish Ferry at Holyhead,
17:14you had to cross this stretch of tidal water,
17:16famous for its strong, fast and deadly currents.
17:25One stormy night in 1785,
17:2755 passengers were stranded on a sandbar when their boat ran aground.
17:32When the tide turned, all but one of them drowned.
17:39Everyone agreed the answer was a bridge.
17:42But how could one be built in such challenging conditions and across such a wide span?
17:47Well, in 1810, Thomas Telford became the fourth engineer in 25 years to rise to the challenge.
17:54And what a challenge it was.
17:56For a start, Telford was a stonemason rather than an ironmaster.
18:00Then there were the straits themselves, which even at their narrowest point are 550 feet wide.
18:06And as if that wasn't enough, the Admiralty insisted that any bridge had to be at least 100 feet above the water
18:12so that their warships could sail beneath it.
18:15So how would Telford do it?
18:17Well, he naturally began by thinking of an arch.
18:20To find out more, I'm meeting local consulting engineer William Day.
18:24Telford started off looking at his favourite structure.
18:27Bear in mind he started out as a mason, so the arch was a natural form to him.
18:32He wanted to build a cast iron arch here.
18:35In fact, it would have been a bridge too far.
18:38500 feet would not have stood given the materials they had.
18:42It would have actually collapsed.
18:45According to conventional engineering wisdom, it simply couldn't be done.
18:49But Telford was about to rewrite the rules.
18:53Very small suspension bridges, of course, had been built before from wood and rope.
18:57But would the same engineering logic work on a much bigger scale, using iron and stone?
19:03Telford built two huge supporting pylons.
19:06From these he hung two massive metal chains, each of them 590 feet long.
19:12Each chain had 935 pieces.
19:15Each chain weighed a hefty 23.5 tonnes.
19:18And it took 150 men with arms like Popeye to haul them into place using ropes and capstans.
19:26Of course, this has changed a lot since Telford's day.
19:29The traffic for a start would have been horse-drawn carriages in those days.
19:32These walkways wouldn't have been here. The walkway was in the middle.
19:35Not a dangerous place to be, I should imagine.
19:38Of course, this steel wasn't here then. This all comes from the 30s.
19:42Still a mighty piece of work, though.
19:45When the bridge opened in 1826, everyone was amazed and delighted.
19:49Everyone except Telford, who thought it might fall down.
19:53Although it was a great success, this bridge was also something that left Telford with great concerns.
20:00He never slept well after building this bridge.
20:05Three years after the Menai Straits Bridge opened,
20:07Telford was asked to judge a competition for an even bigger bridge to cross the Great Avon Gorge.
20:13Telford said it was impossible, but a young man called Isambard Kingdom Brunel proved him wrong.
20:22OK, I admit it, I'm biased. I was born and brought up in the West Country.
20:26So for me, there is only one bridge. Here in Bristol, the Clifton Suspension Bridge.
20:34Brunel wanted to build the biggest suspension bridge in the world, spanning the greatest distance.
20:40An elegant bridge that seemed almost to float across the sky.
20:46He borrowed Telford's idea, but pushed the engineering much further.
20:51The design was fantastically ambitious.
20:54Too ambitious for Thomas Telford, who rejected it as technically impossible,
20:58and chose instead his own design, which didn't span the whole gorge,
21:02but rather rested on two great towers rising from the riverbed.
21:06Mike Rowland, the guide at Clifton, thinks that Bristol's dignitaries were right to overrule Telford.
21:13I dread to think what they would have done to the river traffic,
21:16and of course with the tide, when the high tide came in, the ships would undoubtedly have gone into them.
21:21Bristol sacked Telford as judge and held a fresh contest.
21:26Brunel submitted four designs and went on a charm offensive.
21:29Well, this was his first major project, remember.
21:31He was only 23 years at the time when he won the competition.
21:34Although he did take the judges of the second competition and harangued them for two days,
21:39which was quite something for a young 23-year-old who's unknown,
21:42to take on the great and the good and say, look, this will work.
21:45But this wasn't Brunel's favourite design?
21:47No, it said that his favourite design was what he called the Giant's Hole design.
21:51Now, the cliffs on this side, you can see there's actually a cage just down there.
21:55Now, the cliffs on this side, you can see there's actually a cage just down there.
21:59And the idea was that he would build a tunnel to come out,
22:02straight onto the bridge, go straight across the gorge,
22:05and then into a tunnel on the other side.
22:07So, he wanted a bridge that would match the drama and the splendour of the gorge.
22:13The great, the good and the thrifty picked Brunel's second best design.
22:17Sadly, the bridge wasn't finally completed until after Brunel died,
22:21and the men who built it had the temerity to tinker slightly with the original plans.
22:25But even so, this is very much Brunel's bridge,
22:28and his genius can be seen in every detail.
22:34In fact, Brunel never ceases to amaze.
22:37Four years ago, while boring down through the pavement of one tower,
22:41construction engineers found, to their astonishment,
22:44that the great supporting pier was hollow.
22:48So, Brunel would have to take his top hat off to get through there.
22:51Oh, look at this. Baby stalactites.
22:55What do these faults do structurally for the bridge, then?
22:58Well, this is an abutment, we call it, which is the big square bit,
23:02and the Lee Woods Tower, or the Lee Woods Pier, stands on it.
23:05Brunel built it to bring the tower out, to reduce the length of the central span,
23:10and we'd always thought it was solid.
23:12So, you didn't know this was here until three years ago?
23:14No, until three years ago.
23:15It must have been a shock to you all.
23:16It was. Golly gosh. Yes, it really was.
23:19I think somebody said something like that.
23:26Bristol has long since forgotten the tussles over Brunel's bridge,
23:29and tonight, thousands of locals have gathered to celebrate
23:32the 200th anniversary of the great man's birth
23:34by lighting up what he called his little darling.
23:45It may not be quite the bridge he had in mind,
23:47but still, it's a fantastic memorial to his genius.
23:50Amazing. Everyone loves this bridge.
23:52Look at the crowds. Everyone worships it.
23:54Who cares that it wasn't exactly what Brunel intended?
23:57He was a practical man. He knew about adapting to circumstances.
24:00He would have gone with the flow. He'd have loved this.
24:04CROWD CHATTER
24:11My search for the best of British engineering has brought me to Scotland,
24:15and to a bridge whose story begins with a disaster.
24:21On the night of 28th December 1879,
24:24a Force 10 gale devastated the newly opened Tay Bridge.
24:28It took a train with 75 people to their graves.
24:32The sad irony is, without that disaster,
24:35our next icon wouldn't have been built.
24:38When Tay Bridge collapsed, its designer, Thomas Bouch,
24:41was working on the foundations of a new rail bridge
24:44across the nearby Firth of Forth.
24:47And here are those foundations, only partly finished
24:50because Bouch was blamed for the Tay Bridge disaster
24:53and was sacked from this project.
24:57Instead, a new design team was hired
24:59and given the task of creating a bridge so strong
25:02it couldn't possibly fall down.
25:06What was created was the greatest civil engineering project
25:09of the 19th century, a marvel of girder and rivet,
25:13the Forth Rail Bridge.
25:16MUSIC PLAYS
25:26The Forth Bridge is impressive enough from a distance,
25:29but when you get closer, you realise just how staggeringly massive it is.
25:33120 years after its construction,
25:35this remains the biggest rail bridge in the world.
25:39In its day, it was the biggest structure ever built of steel.
25:43An astounding 55,000 tonnes of the stuff.
25:46And it was also the second tallest structure in the world
25:49after the Eiffel Tower.
25:53I've got a date at the top of this colossus
25:55with the president of the Institute of Civil Engineers, Gordon Masterson.
26:00Wow, look at this. Wow, this is wonderful.
26:03Look at that. Isn't that stunning?
26:05You know what I like most is these sturdy railings around the top here.
26:08That's what I like to see.
26:10That's Edinburgh there, isn't it?
26:12And Arthur's Seat beyond.
26:14OK, a question from the heart now, Gordon.
26:17Why is this bridge such an icon? Why is it so important to you?
26:20Well, for me, I'm a local boy,
26:22so it's got affectionate memories for me as a youngster.
26:26But I think also it's a piece of Scotland's landscape now.
26:30We are standing on the top of our particular piece of world,
26:33and it's man-made, as opposed to Arthur's Seat.
26:36It's just an iconic use of engineering in its best sense.
26:41And it serves a useful purpose.
26:43It's not just a piece of architecture for tourists.
26:46And an achievement for its time in 1890, is it not?
26:49It really was.
26:51I mean, the vision of the engineers that conceived of this bridge
26:55and the constructors who built it is really quite awe-inspiring.
27:03Bridges have to be built on rock.
27:05To get to the rock, engineers on the Forth Bridge
27:08had to sink gigantic cylinders 70 feet in diameter
27:11through the silt on the riverbed.
27:14Once they laid the foundations,
27:16the massive superstructure started to go up.
27:20It took 4,600 men 7½ years to fit all the bits together,
27:25using no less than 6½ million rivets.
27:29The Forth Bridge is so big,
27:31there is a legend that by the time they finish painting it,
27:34it's time to start painting it again.
27:38I decided to see for myself if it's true.
27:40And what do you know? The painters are hard at work.
27:44As you can see from the unpainted bit,
27:46the steelwork's not in bad shape at all.
27:48What you can see peeling off is just the old paint.
27:51Because when it's finished, it'll look like that over there, that column.
27:54Lovely, that beautiful brown colour
27:57that makes us think of the Forth Rail Bridge.
28:00In fact, that colour is called Forth Bridge Red.
28:03How about that? It's got its own paint code, that colour.
28:07I've been told that painting this bridge
28:09costs an eye-watering £10 million a year.
28:12So I thought while I was here I'd lend a hand and save a few quid.
28:18Afternoon, Mick. How are you doing? Nice to meet you.
28:23But before Mick lets me loose, time to get booted and suited.
28:30I can't breathe and I can't speak.
28:33This man's in my Star Wars audition.
28:36Nearly read it all bit, innit?
28:38Just give me a brush, Mick.
28:40Navigating the Forth Bridge is like
28:42clambering around the ribs of a metal dinosaur.
28:45After a brisk five-mile hike, I arrive at the Coalface,
28:48only to find they're painting the thing banana-lemon.
28:53In fact, it's banana-lemon with black spots, just for a change.
28:57It would help if my glasses didn't keep steaming.
29:00Yeah.
29:01All this health and safety equipment makes it very, very dangerous.
29:05Oops, look at this.
29:07It's like North Paris, isn't it?
29:09Can you guess what it is yet?
29:13It's actually the Forth Bridge. Doesn't look like it yet.
29:18The Forth Bridge was one of the great industrial icons of its age.
29:22People who were excited about the modern world loved it.
29:25But the romantic, droopy hippie types,
29:27who painted fairies and wrote sad poems about clouds,
29:30hated the damn thing.
29:32The art critic William Morris described this bridge
29:35as the supremest specimen of all ugliness.
29:39But this is a bridge and he's an art critic.
29:41What does he know?
29:42He should keep his opinions to himself
29:44if he stood here where I'm standing today.
29:46He'd just be knocked out by the sheer size of this
29:50and the incredible skills those men who built this must have had.
29:54What I really love about this series
29:56is how we go and show you something really, really big,
29:59like the Forth Bridge,
30:01and just as you're picking up your jaw from the carpet
30:03and wiping your chin dry,
30:05we go and show you something really, really, really big.
30:09I'm heading 300 miles down the motorway
30:11and 100 years later in time
30:13to see an engineering Leviathan.
30:16Now, I'd like to say that size isn't everything,
30:18but with our next engineering marvel,
30:20size most definitely is everything.
30:23For 17 years, it was the biggest structure of its kind in the world.
30:28Ladies and gentlemen, the Humber Bridge.
30:47This bridge is over 2km long
30:49and is made up of 27,500 tonnes of steel
30:53and 480,000 tonnes of concrete.
30:57The steel cables alone weigh 11,000 tonnes
31:00and there are enough of them to wrap around the earth 2,500 times.
31:04Opened in 1981,
31:06I'm not entirely sure why they built the bridge.
31:08Perhaps Yorkshire ran out of women
31:10and heard there were some really pretty ones in Lincolnshire.
31:13The big question is, has the bridge made a difference?
31:16Well, the ferries used to carry over 90,000 vehicles a year
31:20across the river.
31:21The bridge carries that many cars in a week.
31:27Now, the amazing thing about these towers is they're so high
31:30that they're built 3.6cm further apart at the top than at the bottom
31:34and that is to allow for the curvature of the earth.
31:37Amazing.
31:38Amazing!
31:40But size brings its problems,
31:42as I discovered when I met up with Claire again.
31:45We're still talking about suspension bridges.
31:47Don't tell me it's a suspension bridge.
31:49Yeah, it's got all the bits there.
31:51So what happens is you lie down on the chains,
31:54I get the whip and...
31:56Oh, that's a different programme, sorry.
31:58Does it look anything like the Humber Bridge?
32:00Well, the thing about a suspension bridge
32:02is it's basically a road suspended from cables by other cables, isn't it?
32:06You can see that here, but the Humber Bridge looks absolutely solid.
32:09The Humber Bridge doesn't look as if it obeys the same principles.
32:12But it is exactly the same principles,
32:14and we've got the uprights and the ground anchors as well,
32:17so it's all four bits.
32:18And we need a carriageway, don't we?
32:20Shall I give you a hand with this?
32:22Shall I finish the job off?
32:23Right. I'm glad I'm not going across it.
32:25Well, we'll talk about that.
32:27Have you tested this anywhere else?
32:29Well, I had the dog walking across it.
32:31How heavy is your dog?
32:33It's only a spaniel.
32:34How heavy is your dog?
32:35It's only a spaniel.
32:36All right.
32:38I'm at least 20 spaniels, I'd imagine.
32:41Ow!
32:42Sorry. Now, go on.
32:44I didn't realise you were going to do that.
32:48Riveting.
32:49How are we doing? Is that enough clanky?
32:51Is that enough carriageway?
32:53I think so.
32:55Anchorages.
32:57Now, if it's going to fail, it will fail here.
33:00Because all the weight of the bridge has been taken.
33:02I know. At Humber Bridge, they support 300,000 tonnes, you know.
33:06And I don't weigh that much, but...
33:08So, these support the main chains.
33:10Yep. The chains carry the hangers.
33:12The chains go over the towers.
33:14The chains carry the hangers, which holds up the...
33:17Decking.
33:18Decking.
33:19Is this your first bridge, Claire?
33:21Well, I think we'll talk about that later, Rory.
33:23Why don't you try it out first?
33:24All right, then.
33:25Here goes.
33:27We're up.
33:29It's tilting rather frighteningly.
33:32What are the risks now?
33:33Well, luckily we're not over a ditch,
33:35but you could plummet 60 centimetres to the deck.
33:39A lot of what we call wobble.
33:42You know, we civil engineers.
33:44Oh, I see you're climbing in from the River Humber.
33:47Hey, look at this.
33:48There you are.
33:49We're together on the bridge.
33:54It might be a bit rickety,
33:56but Claire's bit of DIY brilliantly illustrates
33:58one of the most tricky features of a suspension bridge.
34:01It has a rather annoying tendency to wobble.
34:05And like an Englishman's beer gut,
34:07the bigger it is, the more frightening the wobble.
34:10I think you've done a very good job here.
34:12Well, it's showing all the right principles, isn't it?
34:15It is, yeah.
34:17Of course, the attractive wobble at the Humber
34:19came not from giant disco dancing TV presenters.
34:22It was the wind.
34:25The engineering solution was fantastically elegant and clever.
34:30The bridge deck is, in effect, a giant aeroplane wing.
34:42Isn't it a beautiful structure?
34:43I mean, we're rather privileged here
34:45because not many people get this view, do they?
34:47No, down underneath we get a pretty unique view here.
34:51It's nicely sleek, isn't it?
34:53And the aerodynamics, of course, is the big thing.
34:55The Humber Bridge, when it was first built,
34:57that was a unique element.
34:59Essentially, it's an upside-down wing.
35:01The shape of the deck, the wind travelling over the deck
35:04doesn't have to travel as far as under the deck.
35:07So it pulls it down.
35:09It stabilises it.
35:11It pulls it against the hangers.
35:13That was one of the unique parts about the Humber Bridge when it was built.
35:18If Tower Bridge is part bridge and part train,
35:20then this one is part bridge and part plane.
35:23This astonishing place is inside the wing itself,
35:26the streamlined hollow bridge deck.
35:28It's a surreal two-kilometre journey worthy of a sci-fi film.
35:34Peter, this is definitely, without a doubt,
35:36the weirdest place I've ever been.
35:38I've been to some weird places.
35:40I can't believe it.
35:41So where are we now?
35:42Well, we're inside the wing.
35:43We're inside the deck of the bridge.
35:45So that underside...
35:47That's it.
35:48That's it.
35:49That aerodynamic profile we're stood on.
35:51And we can hear the traffic above us.
35:54There is roadway there, 13 millimetres of steel above our heads.
35:58And about nine millimetres of steel below our feet
36:00before the Humber estuary.
36:02So we've got nine millimetres of steel.
36:05Don't do that.
36:08So that's less than a centimetre.
36:10It is, yes.
36:11Keeping us out of the river.
36:12Yes.
36:13How lovely, that's a great thought.
36:14We talked earlier about the movement of the bridge in the wind.
36:17The metal expands and contracts with the temperature going up and down.
36:20There is, yes.
36:21I think one of the most striking, perhaps, figures on that
36:24is the fact that the main cables themselves,
36:27with every one degree rise in temperature,
36:30they expand such that the deck sinks by 150 millimetres.
36:34So the bridge is shorter in winter, longer in summer.
36:36It is, yep.
36:38And during the day, it will expand.
36:41But for the full shock and awe of the Humber Bridge,
36:44there's nothing for it.
36:45I'm going to have to climb 155 metres to the top
36:48of one of its massive supporting towers.
36:56I say, isn't it high up here and scary?
37:01It's like being on top of the Humber Bridge.
37:06Fantastic view.
37:07See my house from here?
37:09Definitely.
37:12You can see Peter Crouch over there in Liverpool.
37:15This is quite stunning.
37:19That is the only time I'm going to do that, OK?
37:21I hope you got that shot.
37:24Right.
37:26Right, I'm going downstairs now.
37:28See you in the lavatory.
37:34Look at that nutcase.
37:35He must be crazy.
37:37That's one thing I'm definitely never going to do.
37:40That and getting off with Jennifer Lopez.
37:45The nutcase, it turns out, is John Williams,
37:47who's in charge of bridge maintenance.
37:52John, that was very, very impressive.
37:54Nice to meet you.
37:55Very scary watching you do that.
37:56Welcome to the top of the bridge.
37:58Not all my worst dreams are about being on high buildings.
38:00You obviously don't get dreams like that.
38:02No, that's not the type of dreams I have.
38:05Right now, you have to inspect all these cables.
38:07You actually abseil down them.
38:09I abseil the tower, the four tower legs, as it were,
38:12the concrete elements.
38:14Occasionally, we actually go down the hangers as well.
38:16That's the suspension cables.
38:18There's a lot of cable here.
38:20There is a lot of cable, yeah.
38:21I'll show you where the cables end up,
38:23and then you'll get a bit more appreciation of what the cables are.
38:25I'm going to have to walk out on there with you.
38:27I'm not doing that.
38:28I'll hold your hand.
38:29Where the cables end up, as John rather quaintly describes it,
38:33is another amazing bit of the Humber Bridge
38:35you never normally get to see.
38:37The only reason the massive towers don't get pulled together
38:40by the weight of the bridge
38:41is that there are cables holding them apart.
38:43Those cables are anchored securely into the ground
38:46on either side of the river.
38:48When I say anchored securely, I'm not kidding.
38:51This is what we call the anchorage block,
38:54and it's doing exactly what it says.
38:56Here we've got the 5mm cables banded together,
38:59anchored at the bottom here.
39:02They're anchored to 190,000 tonnes of concrete.
39:06This is just the tip of the iceberg.
39:08It goes way down.
39:09It goes way, way down.
39:10You can see that is ground level.
39:12Below that, there's another 41 metres of solid concrete.
39:16That's holding the bridge up.
39:17The bridge is held up by 5mm steel cables.
39:20That's amazing.
39:21That's right.
39:22The whole bridge is suspended off these cables.
39:24They're very important.
39:25It's an impressive piece of work.
39:26When you're here, you realise the simplicity
39:28of a suspension bridge structure, don't you?
39:30This is a big cable anchored very well
39:32so you can hang a roadway.
39:34Yes, and just hang the roadway off the suspended cables.
39:37Exactly.
39:38Very simple on a large scale, but very, very effective.
39:41Simple, but complicated.
39:49I think what I love about this bridge
39:50is its simplicity in a way.
39:52It is pure engineering.
39:53There are no architectural frills or extras.
39:56This is an engineer's bridge.
39:58You can see what it does.
39:59It is what it does.
40:01It's functional.
40:02Does that make sense?
40:03The big shame for me is, of course,
40:05that the water isn't blue.
40:07It would be so lovely if we stood up here
40:09sitting down at Aquamarine Blue Sea.
40:11But unfortunately, it's a sea of instant coffee.
40:16The Humber Bridge has taken my breath away.
40:18It's truly awe-inspiring.
40:20I think even Brunel would have been rather impressed.
40:22In fact, it makes you proud to think
40:24that the bold pioneering spirit of Derby,
40:26Telford and Brunel is alive and kicking.
40:30But which of the magnificent bridges I've seen
40:32on my journey is the best?
40:34It's an impossible task.
40:36Balance a pint of beer, flirt with a pretty engineer
40:38and at the same time choose the best bridge in Britain.
40:41In this film, we've been able to feature just a few.
40:44The magical, ingenious Tower Bridge.
40:47Look at this!
40:48The elegant Iron Bridge,
40:49the first ever bridge to be made of cast iron.
40:52Telford's revolutionary Menai Straits Bridge.
40:55Or Brunel's heavenly suspension bridge at Clifton.
40:59Amazing!
41:01The gigantic steel rail bridge across the Firth of Forth.
41:04The phrase, don't look down, springs to mind.
41:07And the even more gigantic Humber Bridge,
41:09until recently the biggest in the world.
41:13It's like being on top of the Humber Bridge.
41:19Let's talk about Tower Bridge.
41:21Very special.
41:22Special is a word. It's awful.
41:24You don't like it?
41:25Absolutely awful.
41:26It's a travesty of engineering.
41:28But it's just so over the top.
41:29It's over-engineered.
41:31It's silly.
41:32You think of it when it dates, for God's sake.
41:34It's got all that sort of false granite,
41:36those towers you don't like.
41:37It's so showy. That's my problem.
41:39But it's a symbol of London.
41:41It's got to be showy.
41:42They don't want naked engineering there.
41:44And it's practical.
41:45It opens up to let ships go through.
41:47OK, OK, OK.
41:48But a more elegant solution to crossing from A to B
41:53has got to be Iron Bridge.
41:55Very, very simple.
41:56Cast iron arch.
41:57Nothing showy about that.
41:59Well, you say there's nothing showy about it,
42:01but the whole thing was in fact an advert
42:03from Derby Steel Company, wasn't it?
42:05And it worked.
42:06It worked.
42:07And it still works to this day.
42:08It's been made by me.
42:09It looks too...
42:10In fact, it's too under-engineered, Iron Bridge, isn't it?
42:12It's just too naked.
42:13It looks like a cast iron arch.
42:14That's what it is.
42:15But if you're talking elegance,
42:16now we've got suspension bridges.
42:18We've got Humber, we've got Minnai and Clifton.
42:20I like the confidence of the Humber Bridge.
42:22Because when it was built,
42:23it's the longest span anywhere in the world, wasn't it?
42:25Well, it's 17 years I'm given to understand.
42:27And that's quite a record.
42:28And that's, you know,
42:29staking your professional reputation on building that.
42:31You've got to have some confidence.
42:32It's one of the things.
42:33It's elegant, it's simplicity.
42:34I mean, it looks like a bridge.
42:36So how can you like that and Tower Bridge at the same time?
42:39You know.
42:40And look, Tower Bridge,
42:41it has to split to let ships through.
42:44Fourth Bridge.
42:46If you're talking over-engineering a fourth bridge,
42:48it's a lot of metal, isn't it?
42:49Yeah, but it had to look strong after the Tate Bridge disaster.
42:52It doesn't move, unlike the Humber Bridge,
42:54which is swinging around in the wind all the time.
42:56No, I'm afraid I'm going to go with Humber Bridge.
42:58Iron Bridge for me.
43:00OK.
43:01Claire, we've built bridges between each other, haven't we, in this programme?
43:05You're going to make me cry in a minute, Rory.
43:07Goodbye.