this is the Milow Viaduct the tallest bridge in the world its highest tower stretches a staggering 343 M so high the bridge Glides above the clouds but this is a mega structure they said couldn't be built when I've shown first the drawing of this bridge they really thought I was crazy the team attempting to build this amazing freeway in the sky had to survive lands slides fight winds gusting at 130 km an hour and weather massive storms as the bridge simply hung in the balance it's a bridge that pushes the boundaries of engineering to the limits and then beyond [Music] [Music] imagine building a series of Eiffel Towers then slinging a four-lane highway between them all the way across one of the deepest valleys in France impossible though it sounds that pretty much describes the building of the Milow Viaduct from the start the construction team faced three daunting challenges one build the tallest bridge piers in the world two put a 36,000 ton freeway on top of them and three erect seven steel pylons each weighing 700 tons and once more they had to do this hundreds of meters above Solid Ground so high that if you were on top of the Eiffel Tower you'd still be looking up at this awesome Bridge October 2001 the team break ground they're required to build a bridge that will last for 100 20 years and to win the contract the teams promised to build it in record time less than 4 years by comparison the world's longest suspension bridge the Akashi Kyo and Japan took a full 10 years to build to up the ante any delay will cost them $30,000 a day in penalties there are seven peers that are numbered from the Northern end of the valley number one will pose problems because of the steep slope number two will be the biggest challenge since it's the tallest crossing the river number three is not much shorter then 4 5 6 and 7even climb the gentler slope to the South [Music] to begin the team had to bury the foundations deep in the bedrock in order to support the enormous weight the bridge will place on them but the forces of nature were stacked against them geologists have warned of the risks posed by the Region's fractured Limestone the rock is full of cavities cavities that are essential to the local cheese economy these cave systems close to meao are home to a unique bacteria responsible for the blue mold in the world famous rock for cheese but what's perfect for cheese could be disastrous for a mega structure the geologist diagnosis spelled one thing landslides this kind of catastrophe could jeopardize the entire project despite the warnings bill building went ahead as planned then well into construction as predicted a dramatic storm causes a landslide 4,000 cubic M of rock collapse around Pier 1 fortunately the Fallen Rock doesn't damage the pier but the warning is clear they're forced to divert precious Manpower and equipment to stabilize the slope and prevent a repeat collapse so if the area is prone to landslides why did they build the world's tallest bridge here in the first place the answer is simple in the 1980s France built a freeway linking Paris directly with Spain this major artery headed south across the French Countryside while from the Mediterranean the freeway headed north until they both hit one of the deepest valleys in France and stop [Music] dead welcome to milao France's least favorite bottleneck the town of milao is in the mountainous region of the m Mass sentral one of the most tranquil parts of France but in summer this poor medieval Town suffered traffic hell the locals couldn't take it anymore neither could their may this it was terrible for our reputation when you hear every day on the television and radio AV void Milow there's a traffic back up a 5H hour wait in malow and it's not just the people of malao two drivers jamaa and jamaa crossing the 30 odd kilm between the freeway on either side of malao reveal exactly why this bridge is needed Jamila in car 33 will cross the new bridge while in car 22 Jima will take the old road across the valley floor getting straight on the freeway car 33 approaches the malao bridge after just 18 minutes the only delay is the 30 seconds it takes to get through the toll then driving at 100 km an hour over the spectacular Bridge she takes just 32 minutes to get to the other side car 22 meanwhile is just beginning the crawl through the medieval streets of malao cyclists pedestrians people with dogs all need to be negotiated car 22 then has the long Hall up the other side of the valley the final timing is a staggering 1 hour and 35 minutes over an hour longer than Jam who took the freeway and Bridge it's clear exactly why the bridge was needed but it took the French government a very long time to get round to building it 12 years before construction began up in Paris the Ministry of Transport first came up with a plan their head bridge builder Michelle voger is no ordinary engineer he's a man who thinks big very big like the Normandy bridge in northern France the longest cable State Span in the world with this record-breaking structure completed vloer was on to his next milao his plan and another cable Stay Bridge but pushing the technology beyond anything previously attempted with peers four times higher than the Normandy Bridge the malao bridge would not only be the world's tallest it would be unlike any Bridge ever constructed when I've shown first the drawing of this bridge to to the convenient authorities they really thought I was crazy villager Normandy Bridge has two sets of cables supporting the deck but he wanted to up the stakes for malao by losing one row of cables so the remaining line would be forced to do twice the work more dramatically the 2.5 km Mala Bridge instead of having a single main span needed a whole series of peers to support it across the valley no Bridge Builders had ever attempted a multiple span single line cable Stay Bridge on this scale before the French authorities had a problem nervous about villager's groundbreaking scheme they held a competition inviting other engineers and Architects to compete with different designs the winner Lord Norman Foster is one of the world's Superstar architects in Hong Kong he built the world's largest Airport terminal in Barcelona offices literally hang from a mast on his Communications Tower this is a man who regularly contemplates The Impossible and delivers you know it's the challenges and it's one Challenge on top of another on top of another and with malao one of the biggest challenges was making it fit into the landscape given it just down the road from the famous Gorge dutan Fran is equivalent of the Grand Canyon how do you make something which has to be so immensely strong against the forces of nature look very gentle very delicate how do you weave something on that scale into the most unbelievable landscape ironically Foster's answer was to take villager's pioneering scheme then push it one stage further he turned An Elegant piece of engineering into a delicate work of art by boldly cutting out two of the nine original peers and seriously slimming down the remaining peers and Road deck fosto wanted the bridge to appear as delicate as a butterfly but this butterfly has to support the weight of five Eiffel Towers in gale force winds hundreds of meters above the river tan getting the design wrong would be a disaster then with malal still on the drawing board Fosters record as a bridge builder suffered a major setback his Millennium bridge in London is actually another record-breaking structure the lowest profile suspension bridge in the world but when this foot Bridge opened to the public in June 2000 it was a public relations disaster crowds walking over it set up a resonant fre frequency and the bridge began to sway as people adjusted their step to the small initial Wobble the effect was magnified though it didn't threaten the structure The Swinging motion became so dramatic the authorities closed the bridge for a refit that took 1 and a half years and ended up costing over $8 million it was a bad Omen for the Mala bridge where construction was soon to begin and at 15 times the height a design floor would be a catastroph [Music] December 2001 Fran's malao Viaduct the tallest bridge in the world is under construction everything about this project is supersized it'll need 200,000 tons of concrete so much that the team have to build a concrete Factory on site but there's nothing straightforward about this concrete the formula must be just right it needs structural strength to support the massive loads at have to bear but it can't set too quickly as it has to be hoisted into position and poured hundreds of meters in the air and it needs to be just the right color to suit Norman Foster's Vision in fact the architect's Vision has created a headache for the construction team he's designed each pair as a complicated geometric shape tapering the entire way up with vertical Groove set into them to create Shadows but what's just a line on paper for the architect was a major challenge to build the enormous Pier are built step by step by pouring concrete into a temporary mold to give the required strength the molds are filled with a frame of Steel reinforcing bars in total 16,000 tons of these steel bars are hoisted into place and secured laid end to end they stretched the 4,000 km from malal all the way to Central Africa the shape of each Pier is seriously complicated as a result each time they remove the sections of Red Steel shuttering they have to change the shape of the mold to fit the profile of the next 4 M section manhandling these steel panels weighing up to 15 Tons a piece is no picnic and with a combined height of the seven p totaling well over a kilometer they have to change the shape of the mold over 250 times every 3 days each team on each Pier went through this whole cycle then they repeated the process but it was a Race Against Time with a permanent threat of delay keeping the entire build on time and to budget was the daunting responsibility of one man Jean Pierre Martin if you said a three days we took four imagine that multiply by the number of castings we'd end up with a three or six month delay with a penalty of nearly a million dollar a month this isn't something mat wanted to contemplate and this schedule wasn't his only headache you have to be pinpoint accurate when you're Building the tallest bridge piers in the world get it wrong and the bridge simply won't fit together just 10 cm out about a hands width on each 4 M section and the tallest pair could be 6 M off at the top the width of a jumbo jet fuselage each team was aiming for a specific point in the sky for Pier 2 this was exactly 245 m above the ground 546 M from the north side and 1,914 M from the southern end there was no room for error the only chance they had to get it right was with GPS accurate to within 4 mm using signals from multiple satellites the team could pinpoint their position and make sure they're on target for that critical point in the sky they needed to hit month after month the p te climbed higher finally by November 2003 they reached their full height at 245 M Pier 2 becomes the highest bridge pier in the world but is this record-breaking pillar where it's supposed to be amazingly it's dead on target to within 2 cm champagne corks pop it's time for a major [Music] celebration against all the odds they were one month ahead of schedule but the team couldn't afford to relax the next stage of the project would be the most difficult part of the build phase two of building the world's tallest bridge involves putting a 2 and 1/2 km roadway weighing 36,000 tons on top of the piers a full 270 m above the river tar Bridge Builders know danger comes with the territory but working at these Heights can be lethal more than 34 died constructing New York's Brooklyn Bridge 35 died in 1970 on the Westgate bridge in Melbourne Australia and one year later 13 workers were killed when the Kenbridge in Germany collapsed into the [Music] Rind with these fatalities in mind the team decided to fabricate the entire Road deck on the safety of solid ground this meant building it in steel which in Theory would be much safer than lifting vast concrete sections hundreds of meters into position there's only one problem with this plan no one had ever put a road deck on Piers anything like this height before let alone over a 2 and 1/2 km Span in the end only one steel manufacturer had the courage to take on this colossal challenge Eiffel the steel firm set up by the great great French engineer Eiffel built what was once the tallest bridge in the world the Gabby viaduct in southern France before getting round to the framing for New York Statue of Liberty and of course his signature Tower in Paris but despite the company's experience eiffel's director Mark buano knew he was taking a serious risk it was a gamble for the company because if there had been a mistake if it hadn't worked it would have been the whole company they fabricated the massive sections that would make up the road deck in the company's steel factories this immense jigsaw puzzle involved manufacturing 2,200 separate sections when up to 90 tons and some of them 22 M long their accuracy is measured with a laser to within a fraction of a millimeter the huge Square tubes are the central spine that should make the deck rigid the Triangular side panels will be welded on either side to create the width for a four-lane highway to meet the punishing schedule buano or automated the manufacturing with a two-headed welding robot and a plasma cutting machine each cutting padn or template is programmed into the computer then the machine automatically blazes its way through the steel the torch reaches a scorching 28,000 de Centigrade that's five times the temperature of the Earth's inner core but cutting and Welding was the easy part the hard part was getting these monster sections the hundreds of kilometers from the factories to mow the routs had to be planned with Precision to avoid major damage the police coordinated safety and clearances even with that level of preparation some obstacles felt as if they're cutting it just too close for comfort [Music] and this was no one-off event to build the viaduct took over 2,000 of these extraordinary Road convoys the components arrived at assembly plant set up one on either side of the valley here the pieces of a massive jigsaw puzzle were welded together to form the two halves of the deck but getting these two halves to span the Val on top of the world's tallest bridge Piers would be a major challenge they'd be the first team to put a road deck on a pier taller than an 80 story skyscraper and pushing bridge building beyond anything attempted before they plan to slide the entire 2 and 1/2 km Road deck over in two colossal pieces the bridges chief engineer Jean Mari kemer was one of the few people who believed it could be done all the engineers who know this method who were in The know didn't believe it was possible if the team had got their calculations wrong the entire structure could collapse into the [Music] valley we found a solution for the construction which was to launch the bridge from the two sides one part on the larac plateau one on the Rouge plateau and to push them from the two sides and to make them come and meet here above the river tar smaller Bridges use a similar technique a powerful set of hydraulic ramps literally pumps the deck from one side to the other but Mila would be the longest launch ever attempted over the highest peers in the world and the results could spell disaster the deck is so slender it would bend and collapse if it were pushed out over the 342 M spans between each Pier the furthest anyone's previously managed is less than half that distance the first part of the solution was simple fit a pylon so its caes support the front of the deck as it goes out over the valley then construct temporary steel support towers that Harve the spans to a more manageable 171 M these steel Towers were a construction feet in themselves the largest over 170 M high is the tallest ever built and they needed to carry a massive load 7,000 tons as the Leading Edge of the deck together with the first 90 M pylon slide over and simply pushing this enormous weight over the top of the vulnerable pear would bring them crashing to the ground this was The Nightmare scenario if we'd done a conventional launch we would have knocked the peers over like the pins in a bowling [Music] alley someone needed to reinvent the way this type of bridge is built and it's Mark buano with Jean Mari Kremer who came up with a breakthrough the basic principle can be demonstrated with a heavy box and a wobbly table with a normal launch you knock over the peers I want to advance the deck over the pier but if I push the deck from here I'd knock over the peers because they're so tall the idea is to install a launching system on top of the pier and that way if I push the deck it has no effect on the stability of the peers and the peers won't fall over the trick is to use a series of these launching systems to jack up the deck and inch It Forward each system uses two wedge shaped blocks under each side of the deck the upper wedge is pulled forward by a hydraulic ram it slides up the slope of the lower wedge at the same time lifting the deck from its supports and advancing at 600 mm the lower wedge then retracts dropping the deck onto its supports the upper wedge returns to its original position and the whole cycle begins again four of these clever devices are placed on each pair all programmed to work at exactly the same time the result is that together they pick up the entire roadway and shunt it forward but if one fails or gets out of Step it could spell disaster the force could push the bridge Piers apart till they collapse when you're up there and you see Mal 300 M below you you asked yourself was this a good idea the future of the entire project was now hanging on a prototype and it had never been tested it's the morning of February 26th 2003 Do or Die day for the world's tallest bridge everything is about to be put to the test the flexibility of the deck the strength of the temporary peers and critically the pioneering hydraulic ram system even buano the man in charge of the launch had his doubts as it had never been done before I have to tell you I had fears that it wouldn't work the pumps kick in the Pistons start to push and the deck begins its huge journey across the valley the moment I heard the motor start I put my finger on the deck and I could feel my finger move every 4 minutes the deck Advanced 600 mm across the valley surveyors tracked its progress but it was still a nail-biting time as they watched the unsupported Deck Crossing the void eventually the deck reached the safety of the first Pier 204 M down only 2,256 to go the launching system seemed to be working as planned the engineers were feeling optimistic but as the deck advances into space it'll become more vulnerable to the wind which can reach 130 km an hour unfortunately the road deck has the shape of an upside down airplane wing and the team's greatest fear is that this Wing could simply take off the engineers kept a close eye on the wind and weather conditions when they were satisfied there was a 3-day weather window and the wind wouldn't exceed 85 km an hour they'd give the construction team the go-ahead and the deck launch could continue the reason for this precaution is simple strong winds can literally tear a bridge apart in 1940 Washington State built a suspension bridge across the Tacoma Narrows in the US Northwest it opened with a Grand ceremony on July the 1st but the celebrations were shortlived the bridge had a major problem the wind girders beneath the deck designed to make the bridge rigid actually blocked the wind causing the roadway to Ripple alarmingly locals soon dubbed it Galloping Gerty on the 7th of November with the wind less than 70 km an hour the bridge begins to twist violently at 11:00 a.m. time runs out for Galloping Gerty the wind sends the bridge crashing into the River Wind Tunnel testing is now standard procedure as a direct result of Galloping gerti for the malow Bridge they analyzed the wind in the tar Valley over 18 months then recreated those conditions in the Wind Tunnel wind engineer Olivier flamon was shocked by the results the average wind speed was relatively low but because the such strong turbulence it created very fast Peak winds the rugged terrain creates serious turbulance at the height of the road deck winds Peak at 130 kmph that's Hur Force they tested every aspect of the bridge to analyze the risks peers pylons and critically the deck but it's not just the aerodynamics of the finished Bridge they needed to find out how it would behave when it was most at risk during the launching of the deck Olivia and his team reached a chilling conclusion the winds they've measured are strong enough to blow the unsecured deck off its supports and send it crashing hundreds of feet to the valley [Music] floor and then the nightmare began on the 22nd of August 2003 6 months into the deck launch one of the launch systems failed leaving the deck hanging in the wind to make matters worse the weathermen were predicting storms so far these massive pumping machines had worked perfectly but the fact is they were prototypes and due to the Frantic schedule they'd never been tested the problem was that the non-stick Teflon between the sliding surfaces had ripped and the friction generated was too much for the hydraulic Rams to push against unfortunately no one had planned on replacing parts of this monster machine mid launch on the top of a massive concrete pillar this was very bad news for the man who staked his reputation on this system it was maximum stress like poison in your mouth you don't forget that re-examining their calculations they realized the cause of the problem they had underestimated the forces between sliding surfaces but they wouldn't be able to repair it without the necessary spare parts the Clock Was ticking and Mark buano needed a solution fast when Apollo 13 came back with that incident the NASA Engineers requested they did the inventory of everything there was on board to know how to fix it the malao team did an inventory they realized that the other launching machines not yet being used could be stripped provide the new Teflon Services they needed working all through the night the team extended the access platform this allowed them to take out the 5 m long 2 ton steel wedges replace the Teflon and reassemble the launching Machine by 8:00 a.m. the next morning it was ready to resume the launch the rest of the week the predicted storm arrived and another set of launching machines wore out so when the deck finally made it to the safety of the next Pier the team breathed a major sigh of relief you don't forget that I won't forget that for 4 hours I was really scared the two decks continued their journey across the valley day after day week after week for a full 14 months they approached each other millimeter by millimeter by May 2004 they' reached a critical phase from the Northern end the shorter deck had traveled 717 M into space to reach its final resting place from the south the longer deck extended over 1.5 km only the section over the river the one point where it was impossible to erect a temporary Pier divided them but would they meet as planned if they've got their calculations wrong they'll have built the biggest white elephant in Europe even The Man Behind the whole project had his doubts I was not convinced at all that the two parts of the deck could meet exactly with a perfect geometry the odds were against them calculating such a feat so precisely is a Herculean task firstly the two starting points on the northern and southern slopes of the valley are at different heights secondly the bridge has a subtle curve to it as a result each steel panel which makes up the road deck had to be cut and welded with extreme Precision it would be an engineering Triumph if they got these two sloping curves decks to meet as required the team checked the weather reports With the Wind inside safety limits they gave the go-ahead for the final push the Rams began to drive the deck's Leading Edge off the safety of Pier 3 towards its destination at this point a total of 21 launching systems needed to move at exactly the same moment to avoid disaster if anything were to go wrong now the man responsible would be Mark buano everyone asked me how can you be sure that it will go straight so to be sure that they were going to the right place I had a GPS put on the front so I could see the gap between the theoretical and the real position over the next two days and nights the deck advances 600 mm at a time towards its final resting place the world's media are watching the critical meeting of the decks and to add to the pressure the French prime minister is due to drop in to celebrate the event the deck pushes forward now with only cenm separating the two sections a magnum of champagne is hung between them to Mark the moment at last Union the two massive steel decks have traveled High over this Valley a total of 2.5 km and when they check they're aligned to within 1 cm that's accurate to within 99.9999% all the measuring all the calculations have paid off they've nailed [Music] it the meeting of the deck was a special moment news reports traveled around the world and in saltzburg Austria they reached Felix bomgardner AKA Felix the Conqueror Felix has made a career base jumping from some of the tallest structures on the planet and within 24 hours he driven to malao and was calculating the logistics for the jump factoring in his two main aims to avoid arrest and death Bal Gartner waited for darkness before arriving on site he found his way to the base of Pier 2 then climbed an access ladder the full 245 m to the top he entered the Steel Road deck and found a place to hide until Daybreak he had to remain concealed until the sun was high enough for his cameramen to record his world record attempt at 7 a.m. the following morning Felix the Conqueror emerged he took a cool backward flip off the tallest bridge in the world and entered the record [Music] books the tallest bridge in the world 250 M I did it and having evaded death he made sure he's not caught by the police [Music] the decks have been joined and the team have reached the final phase of the project but there was still a race to meet the schedule and their problems weren't over yet everyone could see the dramatic undulations in the flexible steel deck even some hardened Bridge Builders wondered about its structural Integrity it a huge surprise for everyone all the engineers said we knew steel was flexible but not that flexible the team were relying on the pylons and cables to pull the deck straight each massive pylon is 90 M high and weighs 700 tons the equivalent of 85 London buses placing them in position on the Slender deck high above the valley floor would go beyond anything ever attempted once again mark buano had a plan you know the first people to make vertical pylons were the Egyptians buano adapted a technique used in ancient Egypt to erect obelisks in the sands on top of the road deck the team put up two enormous steel Towers both of them secured by cables and equipped with a hydraulic system capable of raising 1,000 tons the 700 ton pylon is then lifted by the Hydraulics as it rises it pivots little by little until it's vertical it's then lowered safely onto its Anchorage Point Pano's 4,000-year-old technique worked to Perfection with all seven pylons in place the team could attach the cable stays that would straighten the Rippling deck and give it the strength to cope with full traffic loads they hope the weight of the roadway is now over 40,000 tons the equivalent of a cruise ship and the 154 cable stays should prevent it from sagging or collapsing the strongest stays are made up of 91 individual steel strands and have a breaking strength of 25,000 tons strong enough to hold back 25 jumbo Jets all at Full Throttle as the C stays attention true to plan the ripples in the road deck are pulled straight over the 2.5 km deck the ripples are now no larger than the size of a thumb they're finally on the home straight the road surface goes on adding a further 10,000 tons to the load that's like driving 153 battle tanks onto the deck but before it could open to the public the team needed to know the bridge is safe it would have to pass one crucial [Music] test after 3 years the construction team building France's malao Viaduct the world's tallest bridge are about to find out if they got their calculations right on a single span cable Stay Bridge like the Normandy Bridge a large load on the main section is no problem because the cables are attached to Solid Ground and can't give on the Mala Viaduct with its eight spans the cables are attached to the deck of the adjacent sections a load on one section will cause it to drop pulling the stays down as the pylons lean in the matching stays are pulled upwards lifting the neighboring decks and causing a dangerous Rippling effect it's right now the team put their bridge to the test these 28 trucks have a combined weight of over 900 tons they are now positioned in the critical point midspan the engineers hold their breath measurements are taken the span bends just 26 CM this is a trium for the engineers the bridge was designed to cope with more than double bat four weeks later on December the 14th 2004 president Jac Shirak officially opened the malao bridge a proud moment for the whole of [Music] [Applause] France just over 3 years of construction have produced the tallest bridge in the world designed to last at least 120 years and against the odds the project manager even brought the job in on time but that's not what he's most proud about what I remember because in construction sites there are of an accidents is that we had no serious accidents nothing more than a minor injury as soon as it opened to the public the bridge was an instant success but the real test is until its first Summer and the French all take their vacation no one ever expected anything like this numbers peaked at more than 50,000 Vehicles a day at over $7 per car that's great news for the construction company who are cloring back their $478 million investment in the project this was an epic bridge to build but it's just as epic to maintain tiar and Frank are assigned to P2 the world's tallest bridge Pier this structure is no solid concrete block it's a series of vast Hollow spaces their job today is to test the communication system and electric circuits on each of the seven structural floors this involves a 343 M climb going hand over hand up a ladder for the rest of the day by dusk when tieri finally reaches the summit of the pylon he may be exhausted but there is a payoff you get a fantastic View From Here a 360° [Music] Panorama the tallest bridge in the world has become an icon but this is creating problems no one had ever imagined locals have been taking over the bridge as a platform to get media attention for their causes this crowd was hoping that driving sheep over this freeway in the sky would help them get more farming subsidies Jose's job is to prevent this kind of incident from creating a danger and on this bridge the incidents keep on happening an alarm triggered by a motion detection system means there's a stopped vehicle on the bridge immediately Jose dispatches a colleague to deal with the situation the last thing anyone wants is a multi-car pile up on a 2 and a half kilometer Bridge quarter of a kilometer in the sky Jose Zooms in his camera to reveal the man has left his car and is sitting dangerously on the crash barrier the driver's probably only broken down but already one man who stopped climbed over the wind barrier and jumped to his death Bruno intervenes thankfully it's no more than an irresponsible photographer who sent on his way you could say the malao bridge is a victim of its own success it's definitely become a major tourist destination 700,000 visitors in the first 9 months fortunately most of them wait till they're off the bridge to take their photos it's magnificent I came 600 km today to see them allow vict there's only one thing to say it's extraordinary they're drawn because it's a world beating structure but also because it's incredibly beautiful delicate and minimal not what you'd expect from a structure that's nearly a third taller than any other bridge on the planet and architect Lord Norman Fosters achieved his aim to give the driver the sensation of soaring as you leave these plateaus you do fly you fly across this bridge literally you were above the clouds and the result certainly pleases the man who dreamt it all up to see erected this bridge which I imagine 15 years ago it's something magic this is the longest pure cable Stay Bridge in the world the tallest roadway in the world and of course at 343 M it is the tallest bridge ever constructed [Music]