World’s Most Extreme Bridges | Masters of Engineering | Free Documentary

[Music] reaching the world on the other side crossing the bay first a curiosity then a necessity one which has urged man from the dawn of his history to develop construction methods that enable him to cross barriers but bridges are more than just technological feats they are links between men [Music] leia bello is a geophysicist she'll be following in the footsteps of exceptional builders [Music] revealing the secrets behind the construction of iconic works [Music] and discovering the challenges faced by engineers who build even higher and even further [Music] no engineer in his right mind would have chosen this place to build a bridge unfortunately that was where a bridge was needed a scientific investigation to discover how men design and construct civil structures true expressions of human genius [Music] to bridge the gap [Applause] [Music] leia bello first heads to northeast india and the state of meghalaya to discover a hidden treasure located on the border with bangladesh a third of the state is covered by dense damp forest numerous streams wind through the valley representing obstacles for the movements of the villages for almost 500 years they have intelligently tamed nature by building bridges using the roots of living trees [Music] be careful it's very slippery slowly here is the bridge for you the living root breaks [Music] it's like something out of a fairy tale is the bridge still in use every day every day we have people living in the village on the top they come through this to go to their garden monsoon time it's so much water without this bridge they cannot cross this this kind of activity had been going on for many centuries in this area so it's been a common thing here this is microsticker it has got long stem roots it can sit on rocks and change roots into the stream bed so that's how they started using this it grows very well alongside streams and rivers and see the size of the roots this bridge is so strong it can carry 100 people abandoned in the 1980s in favor of new concrete bridges the living bridges have been the subject of a rehabilitation program launched 15 years ago today local inhabitants protect these wonders of nature in all the valley has about two dozen of these bridges some of which span 20 meters where we are going to show you the last but not the least and the best in this place there are two bridges very special bridge the only one of its the kind in the world is the unique double decker rule bridge unique in the world the living root bridges of meghalaya are also the only bridges to actually get stronger with age this exceptional example of bioengineering illustrates just how man can tame his environment to build footbridges to take him over natural obstacles the first bridges in history were all built using plants or plant-based materials vines rope wooden planks and so on primitive bridges which are still constructed and maintained in some parts of the world like in the foothills of the himalayas in less forested areas man turned to a more resistant material stone some of these prehistoric bridges still stand today [Music] during the final millennia before our era stone dominated the history of bridge building until the romans perfected the art [Music] for almost five centuries the roman empire reigned over europe and the mediterranean to expand their territory the romans developed an important network of roads and bridges this construction-minded people built numerous large-scale structures in stone some of which are still standing after two thousand years like the ponduga in the south of france which was constructed in the middle of the first century of our era its dimensions are impressive 47.6 metres high with a span of meters this iconic vestige is the highest elevated roman aqueduct bridge in the world from the bottom up its three tiers have 6 11 and 35 arches respectively vaulting has been used since the mesopotamian period but not all the time the solution discovered by the romans was to build semicircular arches with centering with the lateral thrust exerted on piles with very strong foundations this produced much wider arch spans from a few meters to 35 meters across once the piles were sunk into the riverbed the next task was to construct the archways the semicircular vaulting forms a structure which can span an empty space with successive arches to build the arches a solid support was needed known as a centering this constituted two wooden semicircles with the same form as the intended arch and served as the framework the blocks of stone were then laid on top of the wooden centering until the last one the keystone [Music] on the first tier of the bridge the arches were thus formed with three parallel sections of stones this form allowed the romans to build arches with unprecedented spans but it did have its limits if an arch were to span more than 40 meters the quantity of stone would be too heavy and the vaulting would collapse under its own weight it's often said that the romans were the greatest builders in antiquity but what do we know about the exact construction techniques and methods they used we know a huge number of things but not everything firstly their construction techniques were absolutely remarkable their level of engineering clearly surpassed that of the ancient greeks who were also great engineers and vitruvius the roman architect and engineer left us the only known book on the subject which we can now consult for all our studies of the archaeology of antiquity vitruvius was the author of the only surviving treaty on the architecture of antiquity it's an expose of the art of roman construction and it lists the tools and techniques employed by these master builders from a theoretical point of view we learn of their acute sense of proportion the lines of their buildings form harmonious dimensions and employ incommensurable numbers such as pi or the square roots of three and five the romans set out to construct for eternity their use of infinite numbers actually enabled them to obtain the absolute and also thanks to this geometrical system stone masons also knew the methods perfectly and so they could reproduce on the spot on a much larger scale of course the plans which had been drawn by the architect while the pond remains a model of aestheticism and architectural perfection it was actually constructed for a very precise purpose to bring fresh water to neem one of the largest cities in gaul with twenty thousand inhabitants [Music] the spring chosen was the fontender some fifty kilometers away from nime the distance wasn't a problem for the architects but something else was [Music] they had hoped to find a spring much higher up than the arrival but point the fontan duro was only 17 meters higher that meant the builders had to construct an aqueduct with an extremely gentle slope one of the gentlest in antiquity how gentle was it 24 centimeters per kilometer [Music] a gradient equivalent to only one millimeter every four meters and without expert calculations it was impossible to ensure a regular slope along the full 50 kilometers of the aqueduct especially across the pond that means that you have a channel with a slope like this fairly steep followed by a very gentle slope and then another steepish one so in the central part the bridge water flowed much more slowly so the result is the water rose in the channel and once the aqueduct was in service they realized that it overflowed from the pondoga so the original wall only came up to here and to stop the water overflowing they had to build up to here exactly this master work of antiquity supplied neem with water for almost 500 years until the fall of the roman empire the construction of immense architectural and engineering works disappeared with the dark ages and was only resumed 500 years later in around the year 1000 with the expansion of christendom and the power of the church the builders of the middle ages re-adopted the techniques and methods of roman architects over the following centuries some bridges were remarkable because houses and shots were constructed on them most of these have disappeared such as the old london bridge and notre dame bridge in paris but others have valiantly survived like the rialto bridge in venice and the ponte vecchio in florence but there was no true architectural evolution until the renaissance between the roman empire and the middle ages there was pretty much no progress from a technical viewpoint the real break came later in the late 17th century early 18th century with a noticeable lightning of the general line of bridges gradually semi-circular arches with centering were replaced by elliptic arches which offered a wider arch span consequently bridges became lighter and slenderer and this meant they could cross greater distances but it wasn't until the middle of the 18th century that the first big technological break came with genre dolph perroni considered to be the father of modern engineering he was also the first to understand the true mechanics of a stone-arched bridge [Music] he established that each arch was not freestanding from the others [Music] and that the thrust was shared between the spans this crucial observation meant that the thickness of a bridge's piles could be considerably reduced [Music] the thickness of the piles he developed an understanding somewhat systematic one could say today of how bridges functioned so he built bridges in a different way to traditional ones with his bridges the thrust of each span kept the others in equilibrium unlike the pond where if one arch collapsed others might yield the arches of the modern bridge were much more interlinked and the thrust went from arch to arch right to the abutments stone thus dominated the history of bridges until the industrial revolution [Music] in the late 18th century early 19th century the mastery of iron allowed engineers to design structures with new profiles iron was the great revolution for bridges it was about 60 times more resistant to pressure and thrust than stone and that would lead to considerably lighter structures iron resisted tensile strength as well as pressure that meant that architects could finally drop the arch which had been the dominant form of bridges since roman times iron enabled builders to construct bridges with triangular crossbars both lighter and more resistant bridges could span even greater distances [Music] the rapid development of the railways demanded new technological solutions to cross rivers and valleys engineers stopped at nothing like spanning the deepest gorges where no one had ever dreamed of taking on nature and bridging the gap [Music] the garabee viaduct is a striking example of this daring it was designed by gustav effel a visionary engineer and determined architect whose solid yet elegant bridges reached heights that gave his contemporaries vertigo located in the heart of the massive central the garabi viaduct crosses extremely undulating terrain 565 meters long and 120 meters high the rail bridge rests on seven piles and a single main arch with a span of 165 meters [Music] what was there here before the construction of the bridge nothing at garabee absolutely nothing they had to lay new roads just to get to the site then they had to construct accommodation for the men who would work on the viaduct why construct a bridge where nothing existed so that the train with its passengers and goods could reach the region as rail was developing everywhere in france there was still no line through the contal department linking paris directly with bezier without skirting around the massive central the gigantic work site began in 1880 the viaduct was erected in just four years an incredible technological feat for the time [Music] keep going almost there the garabee viaduct was the test bed for revolutionary technology and it was while constructing this bridge that gustav ethel patented his famous lattice girders used several years later for the eiffel tower the structure is mesmerizing totally fascinating and in the signature fl style with the open lace girders which allows the wind to pass through that's right it's a very airy structure how is it constructed was the whole thing just assembled here half of it was pre-assembled in the workshops in the valuaapere near paris the other half was hot riveted together here in gariby the wrought iron girders were assembled with rivets these small shafted iron fasteners inserted between each piece of the structure once heated to red or white hot and the tail of the rivet has been hammered flat they hold the pieces together when they cool once the bridge was finished it must have been a huge event for the region yes and not only for the region but the whole civil engineering world the bridge was marveled at due to its height as far as the united states it's one of the two most talked about works by a fell among the hundred he built around the world the garabee viaduct and the eiffel tower erected four years later are testaments to gustav eiffel's genius and perfect mastery of iron iron dominated the history of bridges in the late 19th century constructions multiply throughout europe and the united states but few engineers understood how iron a notably cast iron would react over time with the constant crossings of trains often hastily constructed bridges became the stage of some terrifying disasters [Music] in the united states almost 200 of them collapsed in the 1880s these repeat the end of the iron bridge engineers turned to a new much more resistant material steel an alloy of iron and carbon the development of which took metal work from the domain of craft work into that of science bless you one high quality steel has far superior mechanical qualities compared to iron so you can go much further with it two it had a big impact from the early 20th century on because unlike iron it could be welded and that would totally transform assembly technology today no one would even imagine building a large work of engineering without steel [Music] steel opened the door to rapid technological progress across the globe sleek looking bridges sprung up across rivers breaking records with spans of several hundred meters like the fourth bridge in firth scotland [Music] but back to the early 19th century another method of construction was born in the united states the suspension bridge bridges where the road deck is hung below wire suspension cables firmly anchored in abutments on the riverbanks the suspension bridge is a very simple idea and it's not that complex to construct the main thing back then was to make sure the steel used in wire cables was of good quality so they wouldn't snap there was a lot of debate because for a long time bridges were suspended by chains then by cables then by modern groups of cables with cables made of steel suspension bridges became all the rage but it was the daring of a german-born engineer which would give the united states one of the wonders of the modern world the brooklyn bridge in new york [Music] to better understand how this bridge changed the history of engineering and that of new york leia bellow joins dave frieda on the banks of the east river this photographer a specialist in bridges is a fountain of knowledge when it comes to the brooklyn bridge this legendary bridge 1825 metres across beat all span and height records construction started in 1870 giving rise to an era of ambition and sacrifice of an entire family the roblings john robling who designed the bridge unfortunately he didn't have a chance to see his bridge completed he was surveying the footings for the bridge on the south side of the brooklyn tower a ferry had come in he didn't see it and it crushed his foot and the only treatment he wanted was pouring water on it unfortunately he died of tetanus so his son washington robling then took over as chief engineer so washington was the one who actually built the bridge he went down into the caissons to help the men dig out the muck and the rocks below he wanted to be part of the team but they didn't know again about caisson disease about the change in air pressure he went up being laid up in his bed in his bedroom so his wife emily roebling then transferred all the information from him washington to all the workers so emily robling was very instrumental in helping of building the great brooklyn bridge she was one of the first woman civil engineers that really helped what she did was absolutely incredible i think without emily roebling you wouldn't have the brooklyn bridge today the construction of what was then the world's biggest suspension bridge was dotted with numerous problems and disasters starting with the most ambitious and dangerous stage in the project the sinking of the immense foundations in the bed of the east river the construction of the foundations employed an innovative process washington roebling had two giant wooden caissons made measuring 50 meters long by 30 meters wide the imposing blocks of granite for the towers were laid on top which gradually sank the caissons to the riverbed [Music] once there at a depth of 30 meters compressed air was injected into the giant boxes so they could resist water pressure in this damp cramped pressurized space laborers dug for several months in order to anchor the piles in the bedrock the rubble and mud rose to the surface via a central conduit and within only four years the two towers had begun to rise from the east river at the time little was known of the effects of pressure on the human body contractors and work men began to suffer from strange illnesses the caissons on the manhattan side were at 30 meters deep which means the pressure inside would have been three times more than surface pressure that must be what made it so dangerous for the men working inside when they returned to the surface yes i used to scuba dive so i know the dangers of decompressing if you come out to ambient pressure too fast it's like opening a soda bowl open the top too quick the gases come out too fast that's the same thing with the nitrogen in your blood it would come out it settles into the joints it's extremely painful so they now know you have to come out into ambient pressure very slowly they didn't know that back then so they called it caisson's disease because almost everyone that went into the caisson came out in extreme pain a lot of men died despite the numerous challenges the 90 meter tall towers were completed in 1875 and the installation of the cables could begin [Music] the four main cables these main cables is what holds up the road deck each cable contains wires like this 5434 wires make a 15 and three-quarter inch cable each cable can withstand the pull tension of 25 million pounds they've anchored in anchorages on both sides of the bridge [Music] the main cables are original some of the engineers i know worked on the bridge and the cables the tomato wire like this are in great condition they're galvanized this is the first suspension bridge in the world to use galvanized steel wires it's steel coated with zinc zinc oxidizes but it doesn't rust and it protects the steel underneath it so this could last for 2 300 years easily to prove the solidity of the cables master mechanic e f farrington crossed the east river suspended from them in all 23 000 kilometers of cables were installed after 13 years of work the bridge was finally completed its inauguration on may the 21st 1883 was a national event all of new york was invited the president was here the mayor was here it was called decoration day the entire city basically shut down to celebrate the opening of the brooklyn bridge a week later there was what's called the bridge stampede someone had tripped on decoration day a week later and people thought the bridge was collapsing and a lot of people were trampled to death unfortunately so to compensate for that washington robling had a whole herd of elephants to walk across the bridge and that proved to the public that the bridge was very safe i believe this bridge can last for centuries it is a marvel of engineering hopefully many future new yorkers and other people around the world will be able to see this great structure the roebling's brooklyn bridge is now known the world over and is one of new york's most iconic landmarks over 130 years later it's still standing a genuine work of prowess given the know-how of the time [Music] it inspired other famous large bridges like the washington bridge on the other side of manhattan and the golden gate in san francisco [Music] but other bridges have proved less long lasting the first tacoma narrows bridge in the state of washington would collapse under the effects of a suspension bridge's main enemy the wind last july the nation hailed the opening of the new six and a half million dollar tacoma narrows bridge over puget sound this is the opening of the tacoma narrows bridge right yes it was inaugurated on july 7th 1940 and the bridge started oscillating up and down from the outset during the summer of 1940 people visited the bridge just to see it swaying it became a tourist attraction and it became famous yes from the very beginning except that in november there was the first storm of the fall it wasn't a big storm but there were winds of 70 kilometers an hour through the strait and instead of oscillating up and down the deck started to twist from one side to the other it was an amplitude of almost nine meters and after an hour at about 11 o'clock in the morning the whole central section gave way and collapsed into the tacoma narrows oh yes there it goes which leaves us with a marvelous example of how not to build a suspension bridge one of america's finest structures fortunately the collapse of the bridge claimed no victims except for a terrified dog locked in the car in the middle of the bridge not a person was lost but it's a real tragedy [Music] when the wind blew on the tacoma narrows bridge air pressure was exerted on the edges of the deck transferring its energy into the structure itself and causing the roadway to bend and sway after the collapse of the bridge architects and engineers began to study much more deeply the impact of the wind on bridges but it wasn't until the 1970s that aerodynamics became a science in its own right from then on the decks of bridges were streamlined to facilitate the flow of air around the structure so as to prevent any risk of swaying with the invention and mastery of new materials during the 20th century man would be able to build longer higher bridges with even more impressive dimensions [Music] it was the age of concrete the king of bridge building and much cheaper than steel and it would benefit from a revolutionary process developed by french engineer urgent freshini which was perfect for civil engineering works pre-stressed concrete pre-stressed is concrete that has been compressed so that the traction exerted on it is more than compensated by the stress exerted on it for example if you make a beam out of sugar cubes it won't resist traction at all but if you compress the cubes you can then place a small object on them say an eraser and the sugar beam will hold firm because the disintegrating effect produced by the eraser's weight is nullified by the fact that the cubes are more tightly packed together [Music] this new material has been used on most of the bridges which stand today and it will be used in hybrid bridges such as cable stayed bridges constructed with a mixture of concrete and steel a cable-stayed bridge doesn't need the expensive anchoring of the suspension bridge because the deck is no longer suspended from a gigantic main cable but supported by series of individual cables running directly from the pylons [Music] this new model spread across the globe in the second half of the 20th century breaking all kinds of records like in 1995 with the pond normandy and its span of 856 metres nothing seemed able to halt the ambitions of architects and engineers not even the wrath of nature which has managed to destroy a number of their bridges like during the earthquake in kobe japan in 1995 [Music] across the gulf of corinth stretches the rio anterio bridge it links the peloponnese to mainland greece at a point where two and a half kilometers separate the two shores the region sits between two tectonic plates making it one of the most seismic in europe no engineer in his right mind would have chosen this place to build a bridge unfortunately that was where a bridge was needed project director jean-paul t sandier worked for over five years with overseeing engineer gilda moblong together they came up with unprecedented solutions the first difficulty was the depth of the water 65 meters that's no longer the field of bridge building but of offshore engineering secondly the seabed was of a very poor quality and thirdly there are faults that are constantly active meaning the distance changes between the two coastlines and during a strong earthquake there could be a sudden change of several meters [Music] when we discovered the scale of the work we were sorely tempted to close the file and refuse it at the same time we liked the idea of facing a massive challenge and we thought there must be a solution the bridge has to be capable of withstanding earthquakes of up to seven on the richter scale so the main challenge was to lay sufficiently solid foundations to ward off the wrath of the earth but preliminary studies showed the seabed to be particularly unstable with the poor quality of the sea bed our first idea was the classic one to dig down to find better quality ground but after detailed analysis we soon found out that the bedrock was at a depth of about a thousand meters so that was totally unfeasible and unrealistic then after doing a lot of research we came up with a totally innovative concept due to the extreme depth of the bedrock the engineers soon abandoned the idea of laying foundations under the seabed instead they decided to consolidate it using a brand new solution each of the four huge pylons rest on groups of 200 hollow steel pipes driven into the bed the pipes measure 25 to 30 meters long with a diameter of two meters these were then covered with a bed of gravel three meters thick on which the foundations called pier footings simply rest the dimensions of the footings are gigantic each is divided into 32 compartments and have a diameter of 90 meters they remain the biggest pier footings ever constructed the rio anterio bridge has another particularity rather than lower and upper pylons there are piles of a single block of concrete [Music] the suspended deck is continuous from one end to the other it passes between the pylons and is suspended by only 368 stays it's a genuine floating roadway so in case of an earthquake it can gently sway and to prevent the deck from hitting the pylons the engineers had to come up with an ingenious system to stabilize the bridge [Music] let's start with the big central tube it's a rigid tube which holds the structure transversely in high winds but for a major earthquake which can't be withstood by their rigid support there's a fuse inside which breaks allowing the small tube to enter the big one so one two three four shock absorbers come into play very similar to the shock absorbers in your car when you go into a hole they absorb the energy beneath each of the pylons the deck is maintained by this system of fuses and 10 meter long shock absorbers and over 400 different measuring instruments monitor the bridge's movements in real time on june the 8th 2008 the screen suddenly went berserk when an earthquake of 6.5 magnitude struck the south of greece during the 2008 quake things went according to plan the connections broke the shock absorbers absorbed the shocks and the deck was allowed to sway freely so it was a genuine life-sized test of whether our project was well founded or not thanks to the shock absorbers during an earthquake the deck can move laterally 3.5 meters without hitting the pylons rio anterior is an extraordinary bridge extraordinary because it's a bridge implanted in an extraordinary environment [Music] every bridge marks a victory over the elements earth water and air and a number of them are veritable feats due to the uniqueness of the terrain they cross in the majestic gorge valley of the river town in southern france the mio viaduct has become the new world record holder of bridges with its 2 460 meter cable stayed deck 275 meters in the air it was constructed to free mio of a curse it's constant traffic jams but to re-route the highway the new road would have to cross one of the deepest gorges in europe with a width of two and a half kilometers michelle via lauger is a graduate of france's top engineering school the echo de ponzi schusse he has worked on almost 200 bridges during his career he's known as the father of the pond normandy and participated in the design of the vasco de gama bridge in lisbon portugal at mio the complex geography of the valley was for a long time a real brain teaser for the engineer [Music] several routes were envisaged because we had to cross a large network of valleys at the outset the elevated solution going from plateau to plateau didn't come to mind because of the necessary height of the pylons and then an expert road construction engineer said to us why don't you stay up at the same level as the plateaus and we thought we're stupid that's what we have to do never had engineers built so high up once the route was decided the designer then had to imagine the profile best suited to the landscape [Music] my idea was to construct a cable stayed bridge with multiple spans why because for the bridge to be slender and transparent cable stays would be the best plus it's also the most effective structure to bear the load allow larger spans and thus fewer pylons with british architect norman foster michel villager's team worked on finalizing the plans for the viaduct for almost 10 years work finally began in 2001 a gigantic work site on which mark bonamo worked as the engineer who oversaw the building of the metallic roadway [Music] you feel tiny yes you do how many meters up is it from here to the top 245 meters 245 meters it's the tallest island in the world [Music] with its 2460 meter long deck the mio viaduct is one of the longest cable stayed bridges in the world it rests on seven pairs of piles and pylons 342 meters apart the bridge reaches a maximum height of 343 meters making it taller than the eiffel tower [Music] what's the width at the base of the pylon the base is the size of a tennis court and the concrete is five meters thick underneath there are four big piles 18 meters deep and four meters in diameter and all that anchors this pylon in the rock below during work the seven pylons were built at the same time to gain in speed each was given its own crane to pour in concrete the pylons grew four meters every three days in december 2003 two years after the construction began the pylons were complete each of these splits in two for the last 94 metres a characteristic shape that wasn't chosen by chance a bridge even when constructed to take limited deformations into account remains extremely supple so we had to choose a shape for the piles and pylons to give them the necessary rigidity to restrict deformations while also allowing longitudinal dilations of the deck due to variations in temperature it's to allow for deck movements that the piles and pylons divide into two slender shafts at the top the entire deck was constructed on the ground in workshops on the plateaus either side of the bridge a hundred and fifty men aided by robots carried out over a thousand kilometers of welding to assemble the steel roadway [Music] how did you manage to get the structure in place i came up with the idea of pushing it into position not a classic form of pushing because the pylons are so high the tallest is 245 meters plus they're very flexible so they wouldn't have resisted classic pushing so we invented a sliding system with wedge conveyors our famous wedges each conveyor was made up of two wedges which slide over each other with the use of jacks the first lifting wedge slid under the second supporting the roadway this second wedge was then raised two centimeters and as it was no longer resting on the piles it could advance once in position the first wedge slid again the conveyor was back to its original position and the cycle could recommence to advance the roadway 60 centimeters by 60 centimeters thanks to this system the only one of its kind in the world the north and south sections of the deck joined up in may 2004 after 15 months of sliding [Music] to get the pylons upright the engineers sought inspiration from ancient techniques and developed a tailor-made lifting system they basically copied the model invented by the egyptians to raise their obelisks at luxor [Music] constructors must know all the techniques used for at least the past 4 000 years whether they're egyptian roman 19th century 20th century when you mix all that together you can build great works of civil engineering that will be part of the long history of human construction so it's a blend of history and technology after only three years of work carried out by almost 600 people the completed bridge stood majestically above the gorge of the tan valley it was opened on december the 14th 2004 by then president jacques shirak a proud memory for misha and velozio what really touched me about the occasion was when president shirak got out of his car looked at it and went that was fantastic [Music] more than 10 years after its construction the mio viaduct still holds the record for the tallest pylon in the world but in the past decade other limits have been stretched recently engineers have broken new records with its pylons spaced 1 408 meters apart the cable stayed span record is held by the third bridge across the bosphorus designed by michel vellujo in istanbul and china has recently broken the height record with a bridge culminating at 565 metres above the baipan river so are there any boundaries that can't be crossed [Music] i don't know how far we can push the limits we could envisage wider and wider spans but we'd need a new kind of material traditional materials like concrete and steel will eventually become too heavy for exceptionally wide spans a suspension bridge with steel cables has its limits the moment it can no longer bear its own weight you have to stop things will continue to evolve but in the short term i don't foresee any major revolution before erecting ever bigger bridges engineers will undoubtedly develop new materials but they won't depart from the founding principles which form the singularity of these works of engineering art beauty and efficiency you need the two and that goes back to the principles of vitruvius 2000 years ago which are utilitas fermitas venestas utilitas is usefulness a bridge must have a purpose femitas is resistance a bridge must hold and it must be long lasting and finally venustas which is beauty and elegance [Music] [Music] you

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Keywords: Free Documentary, Documentaries, Full documentary, HD documentary, documentary - topic, documentary (tv genre), engineering, engineering documentary, tech, tech documentary, technology, technology documentary, dam engineering, dam construction, masters of engineering, megastructures, bridge construction, bridge engineering, Danyang–Kunshan Grand Bridge documentary, Danyang–Kunshan Grand Bridge, biggest bridge in the world, worlds biggest bridges, brooklyn bridge, Millau Viaduct

Id: g0WSPkdf1OE

Length: 52min 7sec (3127 seconds)

Published: Fri Nov 20 2020