man's ambition to tame water has led to some incredible construction projects dams canals and even poers to reclaim huge tracks of land from the [Music] sea Frederick Rano is a physicist an expert in fluid dynamics and a researcher at the cnrs he's going to take look at the work of Engineers who have marked our planet's history every single day there was something to resolve now when you look back you're like wow we overcome a lot but you learn these Visionaries tackled immense projects to protect themselves from the often devastating effects of water everything had to be invented nowhere in the world had a structure like this ever been [Music] built and also to harness its tremendous power our scientific investigation will help understand how these extraordinary technical challenges have redrawn the Landscapes of the planet it's the story of Tenacious Engineers who in just a few centuries became the masters of water [Music] [Music] it was here in Corinth almost 3,000 years ago that the idea of building a major canal was first moted the Corinth Canal viewed from the sky it's a trench of more than 6 km long a line between two Seas a spectacular etching of man's desire to master time it's a godsend for the 11,000 boats that use the Corinth Canal each year this Rocky Corridor dug into the narrow strip of land known as an ismos avoids a 400 km detour around the pelan after the failure of projects dating back to Greek and Roman Antiquity the idea of the Corinth Canal fell by the wayside for almost 2,000 years but the development of shipping traffic and world trade in the 19th century reawakened the Ambitions of the Greek people Governor decided that he wanted Greece to develop the opening of the swest canal in 1869 was another ringing Bell for for Greece to move forward and uh well the works began in 1982 after quite an ordeal with studies um Financial issues how much Earth and rock would need to be dug out to produce a trench like this between the panese and Greece that's more than 12 million cubic meters of Earth that has been excavated here and we're talking more than 2,000 workers that were involved in the project also dynamite and nitroglycerin what one of the first projects of uh construction like the canal that has been used here but nitroglycerine is really dangerous it is but um they've tried it so you can see the results the maritime Canal was completed in just 10 years the Corinth Canal's simple construction is called a sea level Canal meaning that it's heun out at the level of the two C's it connects which feed it constantly with saltwater [Music] the technical challenge becomes much greater when fluvial channels have to be bored over long distances rivers and water courses must be diverted to supply these artificial Channels with fresh water and force them through the landscape how to guide a ship up a significant gradient in the 16th century an invention came along that revolutionized the science of canals the lock in addition to its emblematic River the sen since the 19th Century Paris has boasted three lock canals with a total length of 130 km the canal sandini the canal dor and the shortest but most famous the canal samata it's nine locks allow boats to travel in both directions and negotiate an elevation of almost 26 M between the the artificial water course and the river the waterfall at each of these locks is something like 3 m or one story each lock acts like a boat [Music] lift when a boat takes a reach and enters the lock chamber a set of miter Gates form an angle pointing Upstream so that the water tends to close the gates and divert the pressure onto the banks once closed the lock is then emptied Downstream to the lower level thanks to a paddle a small sliding hatch on the Gate of the lock that acts as a valve its role is to fill or empty the lock to balance the water level and therefore the pressure on each side of the gate to facilitate opening initially built of modest size to facilitate Irrigation in the 19th century the development of large canal became vital for both National and international trade by reducing the distances traveled in transporting [Music] goods huge projects began to see the light of day such as the Suez Canal and the Panama Canal The Man Behind both of these humongous projects was the very knowledgeable Ferdinand delps the construction of the seiz canal began in 1859 plans drawn up by the ambitious DPS involve digging a 162 km trench through the desert to connect Europe with Asia without bypassing Africa and the treacherous Seas of the Cape of Good Hope tens of thousands of Egyptian laborers began the work by hand excavators and pickaxes were replaced a few years later by dredging machines such inventions resulting from the Advent of steam significantly reduced the need for Manpower [Music] on November the 17th 1869 the new Waterway was solemnly opened the channel was admired by the whole world for its creator the Canal's completion was a crowning Glory FPS Ferdinand leps achieved a level of Glory which is unimaginable today he went on to tackle international relations and the construction of the Statue of Liberty although he wasn't a writer he was even invited to join the academy Franz his success led to his skills being somewhat overestimated and DPS was convinced that he was the best man to oversee the construction of the Panama Canal this project though proved to be a far more complex one [Music] frederi Rano went to Panama to trace the nightmarish story of the construction of this canal this small Central American country a strip of 725 km of land between Latin America and North America separates the Atlantic from the Pacific in the narrowest area of the ismos covered by dense humid jungle The Man known as the great French man embarked upon the construction of his new inter Oceanic Maritime Canal but the Diplomat blinded by Glory underestimated the climatic geological and economic hurdles that would have to be overcome and despite the reluctance of certain advisers work began in [Music] 1882 as well as discovering a dense tropical forest flooded by torrential rains workers faced another major difficulty a mountainous area the kbra which Rises to 95 m above sea [Music] level they had the geography figured out but not the geology they thought they could carve their way through the mountain a little like the Corinth Canal this turned out to be very crumbly Rock and digging it triggered landslides and those landslides facilitated by the heavy rains destroyed all the sites so they kept having to start again it really was a sopian task before long the workers were suffering from unfamiliar diseases the truth was that the area was infested with mosquitoes carrying yellow fever and malaria death was cutting them down one by one under the helpless gaze of the doctors back then Physicians simply didn't have the scientific knowledge to fight these diseases h s as an example they thought that putting a basin of water at the foot of the bed prevented ants from climbing up to the patient what actually happened was that the mosquitoes were laying their eggs in the water so hospitals were propagating the diseases they were trying to fight [Music] tens of thousands of workers died was a major factor in Ferdinand Lep's downfall unable to stem the epidemic the entrepreneur agreed to review his project backed by Gustav eel he adopted the solution of a canal with locks better suited to the landscape of the region but the turnaround changed nothing after 7 years a billion Franks had been squandered with very little to show on February the 4th 1889 the company went bankrupt when the Panama Scandal broke 85,000 small investors were left [Music] peniles now 88 years old the illustrious DPS was found guilty and only his Advanced age spared him a 5-year prison term while the French lick their wounds the Americans began their move to gain the upper hand in the region Theodore Rosevelt wanted the canal regarding it as the centerpiece of a future world Empire the United States thus redeemed the French concession making the area around the canal US Territory the first priority of Roosevelt's men was to tackle the health issues on in 1903 before continuing the construction work more than a year we spent killing all the mosquitoes in Panama because in the meantime it had been discovered that yellow fever and malaria were carried by mosquitoes the US president then entrusted his army with the mission of finishing one of the largest engineering projects of all time confronted with the same geological difficulties as their predecessors the Americans took the aborted French idea of building a canal with locks to supply them with water they created a dam on the Rio chages flooding a good part of the area and producing a huge artificial lake lake [Music] gatun located 26 M above sea level it allowed the ismos to be crossed without having to excavate the mountain access was by two sets of locks each of size to match the scale of the project boasting 25 M High Gates and 320 M long [Music] locks to stabilize the ships during the passage an Innovative system of locomotives acted as tugs on August the 15th 1914 after a 30-year construction project that claimed the lives of 27,000 men men the gates to this new inter Oceanic Highway were opened the 77 km Canal connecting the Pacific and Atlantic was regarded as the fourth wonder of the world the voyage from San Francisco to New York previously 22,500 km was now only 9,500 km while Europe went to war the young American nation became the world's leading military power and seized control of the region more than 100 years after the first ship sailed along the Canal Panama entered a new era on January the 1st 2000 after some tough negotiations with the USA the country took over the Canal Zone a forest of skyscrapers has grown around old Panama City which is now a major financial center for the canal such commercial success is nothing new together with its Associated activities it represents 40% of the country's economy now the soul Master's in charge the panamanians recently carried out some major Works to provide cargo ships with a brand new canal with [Music] locks it's [Music] incredible hello the Titanic project was supervised by Ilia marota this Panamanian engineer has dedicated 9 years of her life to the canal we needed new logs because shipping uh industry was getting bigger the the vessels were getting bigger and bigger and bigger and we were maxed out so we needed more capacity for more vessels and then we needed to attract bigger vessels that couldn't fit through the existing Panama Canal otherwise we would lose market share and we wouldn't be a world Canal which lock size did you choose so the width is 55 M and the length of this chamber is 427 M and the biggest vessel we can put in is 366 m in length and so far if 49 and a half meter vessel can come in the amazing thing is that it means that you can now fit an Eiffel Tower lengthways in the locks we actually we could have built 19 Eiffel Towers with the amount of Steel that was used to reinforce these concrete walls 19 of them so it's pretty big project yes it's a gigantic project this new project began in January 2007 responding to competition from the suiz Canal Panama is expanding its shipping channels transforming the legendary kbra into a giant Minefield the biggest challenge though lay in the construction of a third set of locks to accommodate even larger ships the new reinforced concrete Chambers have 16 sliding Gates each over 57 M [Music] high after 9 years of work Panama opened its new locks tripling the capacity of cargo ships which can now Embark nearly 14,000 [Music] containers what did you include in the specifications when you decided to build the new locks in the old locks we have locomotives which help position The Vessel in the middle of the chamber here we did not use locomotives why because it was too expensive the walls would have to been heavier to sustain the weight of the locomotives more equipment more people also the locomotives and the cables will have to be too big for these type vessels other than that the gates they're very different the engineers decided on an innovation replacing miter gates with sliding ones The Gaze range from 2,400 tons to 4,200 tons but only 15% of the weight is what gets moved with the motors uh 85% of it is floating because each gate has a floating compartment that allows the gate to be like a ship so it's not that heavy to move it basically you can't mess with Archimedes principle yes the last challenge of this project was to preserve the Water of Lake gon which supplies the canal and its locks each giant container vessel passing through drives no less than 197 million L of water to the ocean gradually emptying this indispensable reserve of fresh water water is key for the Panama Canal because it's also the lake where most of our population drinks water from in the main cities so we have to protect water save water so we decided to implement the water saving basins what they do is all this gravity fed with different elevations of water were're able to recycle 60% of the water per chamber and uh overall these locks use 7% less water than the existing lcks so it's just a recycling system Wars becoming one of the great leaders of the Panama Canal a childhood dream um this is a dream job for any engineer it's uh this project like this doesn't get built every day and it's very unique the locks the gates everything everything the physical systems every single day there was something to resolve now when you look back you're like wow we overcome a lot but you learn that's the beauty so it was more good than bad this technical prowess is also a financial success for the canal Authority every cargo ship passing through pays a colossal sum between 500,000 and $1 million [Music] in an era where 90% of global trade is Seaborn the canal has become the economic heart of Panama and one of the world's leading Trade Centers but the country is already considering a fourth set of even larger locks to accommodate cargo ships over 400 m [Music] long the idea was prompted by China's plan to open a canal in Nicaragua allowing through cargo ships carrying 25,000 containers and in anticipation of the Arctic route opening up as a result of climate change water is a major concern for mankind and Engineers have come up with some brilliant ways to diverted in order to create waterways that considerably reduce travel distances in their attempts to master it some have even managed to redraw the landscape and recover territories from the sea the venetians put some bold strategies into practice when they built a city that should never have existed Venice sprung up in a huge Lagoon dotted with marshy Islands the Hostile site was specifically chosen by the venetians to escape the Barbarian invasions and protect themselves [Music] today it's an architectural treasure a UNESCO world heritage site with its countless canals and palaces Venice is testimony to Mankind's genius for mastering water when the first inhabitants arrived here they learned a specific technique to build houses on this uh uh unstable ground on muddy on a very muddy ground first of all with the technique of bonification and wooden pole they created a basis and below that surface we have millions of poles that have been put to make a stable ground in SAR Square there are possibly 200 300,000 poles and when you are walking through Venice possibly you are walking uh on top of the largest forest fossile forest in Italy it's a very nice example of the way in which V is Master the waters for centuries Masters maybe but still subject to the rhythm of the water aquala uh conditioning very much life for venetians and when it happens everyone is obliged to go into the pasarella also for people uh living in the houses it's very unsafe uh to live uh on the ground floor and uh it's better to stay on the Upper Floor the aqua alter is caused by many factors making it very difficult to predict in Venice tidal phenomena account for only 20 to 30% of the aqua alter during the highest Tides the water rises a maximum of 50 cm [Music] sea level is also affected by atmospheric pressure high pressure above 13 hectopascals forces the sea down while depressions cause it to rise a big depression then can thus raise the Water by up to 30 cm it's often accompanied by heavy rains which make the situation worse finally a strong constant wind blowing towards land can cause a significant rise in the water level LEL of up to 1 [Music] M more and more frequently the Venetian Republic is coming under threat from the Adriatic [Music] Sea every Autumn increasingly high waters flood the city [Music] the worst was probably the aqua Grande of November the 4th 1966 driven by a storm and a strong southeasterly wind the water Rose to 194 CM above the reference [Music] level 5,000 venetians lost their homes concerned that Venice might be swallowed up entirely spread across the [Music] world in the 1970s to save the city a unique barrage was designed in the form of the mo project after 15 years of massive construction works this ingenious system of floating Gates attached to the bottom of the Lagoon is entering its Final [Music] Phase the system is managed from a control center since 2011 whenever floods threaten computers can close the barriers virtually simulating an [Music] emergency on these screens we see the information that the operator will consult when deciding whether or not to operate the gates they arrive directly from each opening and give the status of each slle there is also marine weather data so when do you decide to close an entry the Italian state has defined the rules to put these mobile Gates into operation the water must rise to 1.10 m above the reference level when we decide to lift the gates air is injected they pivot around the hinges to a position of 45° the operational angle to lower them we inject water instead of air and then they sink returning to a horizontal position on the bottom why not tilt the gates at 90° we don't place them vertically because at 90 degrees it would be very difficult to get them back in position on the bottom from 45 degrees Gates can reposition themselves naturally thanks to the force of gravity it's really clever it takes 30 minutes to fill the 78 valves with air and another 30 minutes to bring the gates to operational level the movable barrier is designed to hold back up to 3 m of rising water was global warming taken into account in the mo project yes the mo system is one of the first at the Italian state has carried out taking this problem into account a hypothetical rise in sea levels of up to 6 centers in 100 years has been factored in a high price has been paid by the Italians for this bold technology an estimated 5.5 billion EUR not counting cases of corruption this is the main grievance for the Project's many detractors they complain that the system does nothing to ease the main threat to the city with Venice subsiding by several mm every [Music] year further north in Europe in the Netherlands a whole nation has made the control of water its speciality over the centuries the Dutch have become formidable hydraulic Engineers reclaiming huge tracks of land from the sea more than 20% of their country is built on previously submerged land reclaimed from the sea known as [Music] poers several centuries ago in order to create poers the Dutch first surrounded the area they wanted to build on isolating the marshes to be drained then they planted Reeds to absorb the water but this technique proved to be insufficent ient they went on to cover the area with canals to drain away the water the Dutch then built windmills with a screw to pump the water away discharging it into a channel Upstream towards the rivers or the [Music] sea the Netherlands use more than 10,000 windmills to drain the land in the 20th century Reclamation has intensified complete redrawing the map of the country on January the 1st 1986 a new Province was born called foland the new land was formed by merging two existing poers with an area of 25,000 Square km it's the largest poer in the world and the biggest dewatering project ever [Music] undertaken since the Middle Ages the Dutch have reclaimed an area of 220,000 th000 hectar from the sea but the conquest has not been without consequences 1/3 of the country is below sea level and 60% of the population lives in flood prone [Music] areas in 1953 a devastating storm forever changed the face of the country on February the 1st a very high tide coupled with a depression and roaring 150 kmph winds rose up against the North Sea dkes with phenomenal force in the middle of the night in the south of the country 89 barriers gave way allowing 4 and 1/2 M of glacial water into an area of 200,000 hectar the result was devastating 47,000 buildings were destroyed tens of thousands of animals drowned and most tragically of all 1,835 people died as a result of this unprecedented disas Master the Netherlands set about the largest civil engineering project ever undertaken the Delta plan over a period of 30 years the project aimed to build the most powerful ramparts ever imagined dkes and indestructible dams to lock out almost every arm of the sea and river estery in the south of the territory near Rotterdam stands the Keystone of the Delta plan the Eastern Shelt storm storm surge barrier completed after an extremely complex 10-year construction project this Innovative barrier is several kilom long dozens of 42 M wide 5 m thick steel Gates allow the strong currents of the North Sea to pass through or repel them when the elements go wild I imagine that building such a dam required many Innovations yes everything had to be invented no structure had ever been built like it anywhere in the world the original design of the Delta plan provided for the construction of a conventional closed Dam and work began in 1974 however environmentalists and fishermen protested because the oyster and muscle beds would not have survived it would also have been a disaster for plants and other living organisms so they stopped the procedure and the government decided to build an open Dam instead the engineers had to invent a completely new type of barrier able to support a flow of 2 cubic M of water per second a fix to the seabed are 65 enormous concrete pillars each weighing 18,000 tons between them are sliding steel Gates moved into position from the control room as soon as the water reaches 3 m above the reference level it takes 75 minutes to complete this North Sea Inlet with this Delta plan the Netherlands has become one of the safest Coastal territories in the world thanks to its innumerable dkes and more recently its Mobile water defenses over the centuries the Dutch have been become specialists in mastering water the expertise of their 2500 companies and Laboratories working on the issue is recognized [Music] worldwide in Del Frederick restano an expert in fluid mechanics visited one of the most important hydraulic research centers in the country to find out about the work being carried out by his Dutch colleagues in their quest to develop increasingly effective Coastal Protection Systems [Music] it's really big it is Big yeah 75 M long almost 9 M width in this kind of wave basins we do research on dkes ports storms barrier like a project in Venice the mosa project stormson Beres have been tested in this facility what's special about this Basin yeah this is the Atlantic Basin where we can generate not only waste but also a current so we have waves from that side but we can have currents also from that side and that is important uh if you have for instance U material that is being steered up by the waves and transported by the curs all the experiments here deal with an unpredictable element water in order to simulate Its Behavior and collect accurate data each pool is equipped with one or more wave generators the waves here don't have a very regular form no like in the reality not each wave is the same so when you look to a storm you have higher waves and you have lower waves you have longer waves and you have shorter [Music] waves depending where we are in the world the frequency of the W uh might be different we know how to program that uh to the wave generator uh and that is very essential it's a tool that allows scientists to study the resistance of dkes in the long term as well as in extreme situations for analysis purposes researchers have built a 300 M long Canal this is the distance required to reproduce the gradual formation of waves and allow 4.5 M high waves to be generated giant basins are also also essential for large scale study of how to protect increasingly threatened coastlines has global warming increased demand of course so it is one of the aspects that we deal with in each project we need to construct dkes that we can easily adapt if the sea level rise will be more than what we expect now but if your expectations is is wrong and it's not one meter but it's 2 m or 3 m met then you still should be able to adapt the structure to a different sea level rise here in Holland such tests must be particularly important yes in the Netherlands it's very important that we have facilities like this to investigate if you make an error the consequences are much larger in the Netherlands than in other countries The increased risks led the Dutch government to launch a new Delta plan in 2015 to strengthen and heighten many of the country's surge [Music] barriers a rise in sea level of between 65 and 130 cm is predicted by 2100 and up to 4 M by 2200 aggravated by subsidence of the soil and significant erosion of the coastline in order to limit greenhouse gas emissions Engineers increasingly harness the tremendous power of [Music] water the impressive nature of hydroelectric dams means that they produce almost 80% of the world's renewable energies compared to 12% for wind 7% for biomass 1% for geo thermals and 3% for solar in the 20th century 70 dams in 14 different countries are the work of brilliant French engineer Andre coin the Undisputed Master of the arch Dam his creativity has inspired generations of Builders what characterized Andre Co was his desire to experiment and work things out in the best possible way he made a range of Innovations spillways for example whenever floods occur it is important to protect the foot of the dam from damage by The increased flow he invented what became known as the ski jump which projects the water far enough away to ensure that damage is inconsequential he also pioneered the incorporation of measuring equipment into the concrete the calculations he came up with paved the way for further develop vment of the arch Dam he also insisted that it had to be [Music] beautiful it was Andre coin's philosophy that nature must Prevail we do not impose on nature we take a rather immodest step of barring a river and we need to understand it he was of the view that some kind of empathy must exist with the rock the river the concrete and the Earth putting oneself in Nature's shoes is not being arrogant on the contrary it's a way of submitting to it completely while coin became famous for Arch vaults often built in steep areas there are other types of dams built in rivers such as the gravity Dam all share a common feature to build them Engineers must interrupt the natural water course to build such a structure it's first necessary to drain the area chosen for construction the water course must thus be diverted into the banks through a temporary Channel or in more rugged regions through huge diversion tunnels the excavated rocks are then used to build Coffer dams dkes and temporary barriers that help drain the area once the Watercourse bed is dry excavation can begin the solid it of the support is ensured through intensive studies and high strength concrete is used on any ground deemed unfit for the [Music] foundations once the site is finished the Coffer dams are dismantled to put the dam in water and create its vast Reservoir the quality of the rock is essential in building a dam the moment when a dam is first put in water is one that no engineer not even Andre coin experiences with serenity of all the edifices built by man said coin dams are potentially the deadliest his words were [Music] prophetic in 1954 Andre coin completed the malp arch dam in the south of France the reservoir allowed the farms around fres to be irrigated it was built in the Ron Valley a water course that runs dry in summer and floods in Winter the weight went on for sever several years until the water filled it completely 1955 56 57 and there were no checks there was nobody on the spot since there is no Electric Plant the construction was there purely to collect water there was no monitoring and warning sides went unheeded noises water dripping in some places on the Left Bank the water had infiltrated the rock which caused cracks and faults then on December 2nd 1959 the sandburst at around 9:00 p.m. 40 m high wave rushed into the narrow Valley at a speed of 70 km an hour sweeping away everything in its path breaking on Frasier's 20 minutes later before flowing into the sea the damage was catastrophic claiming more than 423 victims France was in shock Andre coin took full responsibility for the [Music] tragedy when everything was checked there was not a single miscalculation in fact the arch was welld designed it wasn't a design fault it was a geological fault the Malpass tragedy prompted a rethink with Engineers all over the world they realized they didn't understand what was happening in the Rock something we have learned is that The Rock must be allowed to drain by drilling into it and tunneling to ensure there's no buildup of pressure inside the rock much of what we know about drainage and rock mechanics stems from alpas but that doesn't mean it wasn't a dreadful tragedy the biggest civil engineering disaster of the 20th century has significantly improved the safet of dams all are now equipped with drainage [Music] systems with ever large constructions being erected security is an essential element and the energy potential is [Music] immense water is an asset widely exploited in South America particularly in Paraguay which is one of the few countries in the world that is 100% hydroelectric Frederic Rano went to this small state sandwiched between Argentina Bolivia and Brazil although landlocked the country is crossed by one of the largest rivers in Latin America the Parana river which forms a natural border between Brazil and Paraguay driven by several water Force such as salus Delon it drains an immense volume of water with unparalleled power a few kilometers away this resource has allowed Paraguay and Brazil to jointly build the bational [Music] itam it's the most powerful hydroelectric plant in the world and one of the largest dams on [Music] Earth it's a really amazing place it's gigantic how big is it exactly the dam measures nearly 7.5 km it's total height is 225 M 225 m above sea level exactly how high is the waterfall it falls 120 M Water hits each turbine producing 700 megaw so each turbine is roughly the same power as a nuclear reactor the typu has a capacity of 14,000 megaw so compare that with a nuclear plant producing 1,000 megawatts that's the equivalent of 14 nuclear power plants it's really amazing this monster supplies almost 90% of the electricity consumed in Paraguay and 50% of its Brazilian neighbors electrical power thanks to an architecture and location that was thoroughly studied by Engineers what kind of dam is the IU Dam it's a gravity Dam built on very Solid basaltic Rock the same as can be found along the river it was built on the piranha River Canyon the site of the E Taio power station was chosen by Engineers because this was where it was possible to extract the most electrical energy from the flow of water into the power plant they have achieved the best possible rate of productivity so It's a combination of water flow and geology that makes this the optimum location yes completed in 1991 the structure forms a gigantic 1,350 km Reservoir but the sacrifices demanded by this incredible Dam are commensurate with its height to create the lake the authorities had to displace 10,000 families and drown the rainforest beneath 100 m of water the first Dam construction site with an animal rescue plan the site is now classified as a UNESCO biosphere Reserve plant and dams stand on exceptionally strong foundations capable of holding back 29 million cubic M of water [Music] it's gigantic yes it is and so this is the bottom of the Pana River are we really on the river bed that's right these are the foundations it's actually the base the lowest level of the main Dam as you can see here all this rock dates from the time of construction is the toughness of basal important for theu Dam absolutely so the dam is just standing on rock in concrete terms yes but the strength of the dam rests on 81 billion tons of reinforced concrete it's an impressive weight to save concrete and not unduly burden the structure which could damage the bottom of the river the builders designed a Hollow Dam supported by buttresses the architecture redirects forces to the bottom and thanks to its wider base allows it to better withstand the enormous pressure of water the dam thus stabilized the engineers equipped it with 20 gigantic pen stocks creating a drop height of nearly 120 M which discharges 700 cubic M of water per second directly into each turbine [Music] electricity is produced at the foot of the structure in the largest hydroelectric plant in the world this is the big machine room below all these red covers are all the [Music] generators it's crazy to think that this uses a simple principle of physics which is the Dynamo only in absolutely gigantic dimensions all physics is here electricity fluid mechanics electromagnetism everything pretty much everything here we apply practically all the Sciences of engineering but despite their ability to provide clean energy even larger dams involve sacrifices with populations displaced and hydrological regimes and water ecosystems modified [Music] any cost that building this Dam might have had on the environment I can ensure You Are outweighed by the benefits starting by the huge amount of energy produced which is clean and if we look what you would need to do to create the same amount of energy our calculation is about 500,000 barrels of oil per day eost production allows us us to avoid about 85 million tons of CO2 controlling water is first of all about using it in the best way possible but it's also about really understanding the water cycle treating it as well as possible and not spoiling it at any time [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 [Music] men leab Bello is a geophysicist she be following in the footsteps of exceptional [Music] Builders revealing the secrets behind the construction of iconic works and discovering the challenges faced by Engineers who build even higher and even [Music] further 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 to bridge the gap [Music] [Applause] [Music] Leia Bellow first heads to Northeast India and the state of meala 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 tained Nature by Building Bridges using the roots of living [Music] trees B be careful it's very slippery slowly here is the bridge for you the living rout [Music] Bridge see the roots 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 through this to go to the 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 Fus Elastica it has got long stem Roots it can sit on rocks and CH 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 M while we are going to show you the last but not the least and the best in this place there are two es we have the double very special Bridge the only one of its the kind in the world is the unique double decker root Bridge unique in the world the Living Root bridges of meala 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 foot Bridges 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 during the final Millennia before our era Stone dominated the history of bridge building until the Romans perfected the art for almost 5 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 constructionmarch in the middle of the first century of our era its dimensions are impressive 47.6 M high with a span of 275 M this iconic Vesti is the highest elevated Roman aqueduct bridge in in the world from the bottom up its three tiers have 6 11 and 35 arches respectively vating has been used since the Mesopotamian period but not all the time the solution discovered by the Romans was to build semicircular archers with cing with the lateral thrust exerted on piles with very strong foundations this produced much wider arch spans from a few met to 35 M 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 centring 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 Archers were thus formed with three parallel sections of [Music] 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 m 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 pugar remains a model of aestheticism and Architectural Perfection it was actually constructed for a very precise purpose to bring fresh water to neim one of the largest cities in Gaul with 20,000 [Music] inhabitants the spring chosen was the font dur some 50 km away from neem 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 point but unfortunately the Fontan dur was only 17 M 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 cm per kilometer a gradient equivalent to only 1 mm every 4 M and without expert calculations it was impossible to ensure a regular slope along the full 50 km of the aqueduct especially across the pondar 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 pondar so the original wall only came up to here and to stop the water overflowing they had to build up to here exactly this Masterwork 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 1 000 with the expansion of Christendom and the power of the church the Builders of the Middle Ages reopt the techniques and methods of Roman Architects over the following centuries some bridges were remarkable because houses and shops were constructed on them most of these have disappeared such as the old London Bridge a nraam bridge in Paris but others have valiantly survived like the Rialto Bridge in Venice and the ponio 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 semicircular 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 Jean Rolf Hy considered to be the father of modern engineering he was also the first to understand the true mechanics of a stone arched Bridge he established that each Arch was not freestanding from the others 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] P hared 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 P where if one Arch collapsed others might yield the arches of the modern Bridge were much more interl and the thrust went from Arch to Arch right to the abutments stone thus dominated the history of bridges until the Industrial [Music] Revolution 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 the rapid development of the railways demanded new technological solutions to cross rivers and [Music] valleys Engineers stopped at nothing like spanning the deepest Gorges where no one had ever dreamed of taking on nature and bridg the Gap the gab Viaduct is a striking example of this daring it was designed by Gustaf eel a Visionary engineer and determined architect whose solid yet elegant Bridges reached Heights that gave his contempories vertigo located in the heart of the massive sentral the garabi viaduct crosses extremely undulating Terrain 565 M long and 120 M High the rail Bridge rests on seven piles and a single main arch with a span of 165 M what was there here before the construction of the bridge nothing at gab absolutely nothing they had to lay New Roads just to get to the site then they had to construct a accomodation 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 sentral here it is wow the gigantic work site began in 1880 the viaduct was erected in Just 4 years an incredible technological feat for the [Music] time keep going almost there the gab Viaduct was the test bed for revolutionary technology and it was while constructing this bridge that Gustaf eel patented his famous latis girders used several years later for the Eiffel Tower the structure is mesmerizing totally fascinating and in the signature eel Style with the open lace girs which allows the wind to pass through that's right it's a very airy structure how was it constructed was the whole thing just assembled here half of it was pre-assembled in the workshops in lala near Paris the other half was hot riveted together here in garab B the rot 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 call 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 AEL among the hundred he built around the world the Gabi Viaduct and the Eiffel Tower erected four years later a Testaments to Gustaf ael's genius and perfect Mastery of iron iron dominated the history of bridges in the late 19th century constructions multiplied 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 [Music] disasters 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 last year 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 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 F Scotland [Music] [Music] but back to the early 19th century another method of construction was born in the United States the suspension bridge brid bries where the road deck is hung below wire suspension cables firmly anchored in abutments on the river banks 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 leab Bellow joins Dave Freda 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 1,825 M 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 robings John robling who designed the bridge unfortunately he didn't have a chance to see his Bridge completed if 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 tetus 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 kons 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 Quan's disase about the change in air pressure he wind up being laid up in his bed in his bedroom so his wife Emily robling then transferred all the information from him Washington to all the workers so Emily robling was very instrumental in helping of building the brook great Brooklyn Bridge she she was one of the first woman civil engineers that really helped what she did was absolutely incredible I think without Emily robling 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 [Music] River the construction of the foundations employed an Innovative process Washington robling had two giant wood Wen kons made measuring 50 m long by 30 m wide the imposing blocks of granite for the towers were laid on top which gradually sank the kons to the [Music] riverbed once there at a depth of 30 m 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 condu and within only 4 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 workmen began to suffer from strange illnesses the queson on the Manhattan side were at 30 m 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 return 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 bowel 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 quon's disease because almost everyone that went into the quesan came out in extreme pain a lot of men died despite the numerous challenges the 90 M tall towers were completed in 1875 and the in installation of the cables could begin the four main cables these main cables is what holds up the road deck each cable contains wires like this 5,434 wires make a 15 and 3/4 in cable each cable can withstand the pull tension of 25 million PBS they were 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 that's are made of 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 idity of the cables Master Mechanic EF farington crossed the East River suspended from them in all 23,000 km of cables were [Music] 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 May was here it was called Decoration Day the entire city basically shut down to celebrate the opening of the Crooklyn 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 uh hopefully many future New Yorkers and other people around the world will be able to see this great structure the robings 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 knowhow of the time it inspired other famous large bridges like the Washington Bridge on the other side of Manhattan and the Golden Gate in San Francisco 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 $6.5 million Tacoma Narrows Bridge over pitam this is the opening of the Tacoma Naro 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 19 40 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 km an hour through the straight and instead of oscillating up and down the deck started to twist from one side to the the other there was an amplitude of almost 9 M and after an hour at about 11:00 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 suion Bridge one of America's Finest structur 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 [Music] tragedy 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 streamline 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 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 uren frini 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 weight is nullified by the fact that the cubes are more tightly packed together this new material has been used on most of the bridges which stand today and it would 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 this new models spread across the globe in the second half of the 20th century breaking all kinds of Records like in 1995 with the Ponda normandi and its span of 856 M 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 pones to Mainland Greece at a point where 2 and A2 kilometers separate the two Shores the region sits between two tectonic plates making it one of the most seasic 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 Tessier worked for over 5 years with overseeing engineer Jil de moan together they came up with unprecedented Solutions the first difficulty was the depth of the water 65 M 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 when we discovered the scale of the work we were sorely tempted to close the file and refuse it at the same time we like 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 RoR 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 seabed 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 1,000 M 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 measured 25 to 30 m long with a diameter of 2 m these were then covered with a bed of gravel 3 m thick on which the foundations called peer footings simply rest the dimensions of the footings are gigantic each is divided into 32 compartments and have a diameter of 90 M they Remain the biggest Pier footings ever constructed the Rio anterior Bridge has another particularity rather than lower and upper pylons there are pylons of a single block of concrete 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 let's start with the big Central tube it's a rigid tube which holds the structure transversally 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 m 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-size test of whether our project was well founded or not thanks to the shock absorbers during an earthquake the debt can move laterally 3.5 m without hitting the pylons Rio anterio is an extraordinary Bridge extraordinary because it's a bridge implanted in an extraordinary [Music] environment 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 Tan in southern France the Mio Viaduct has become the new world record holder of bridges with its 2,460 M cable stay deck 275 m in the air it was constructed to free Mio of a curse it's constant traffic jams but to rout the highway the new road would have to cross one of the deepest Gorges in Europe with a width of 2 and 1/2 [Music] km Michelle V is a graduate of France's top engineering school the deoni he has worked on almost 200 Bridges during his career he's known as the father of the pond normandi and participated in the design of the Vasco de gamma bridge in Lisbon Portugal at Mi the complex geography of the valley was for a long time a real brain teaser for the engineer 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 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 beer the load allow larger spans and thus fewer pylons with British architect Norman Foster Michelle 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 bamore worked as the engineer who oversaw the building of the metallic roadway you feel tiny yes you do how many meters up is it from here to the top 245 M 245 M it's the tallest pylon in the [Music] world with its 2,460 M 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 M apart the bridge reaches a maximum height of 343 M making it taller than the Eiffel [Music] Tower what's the width at the base of the pylon the base is the size of a tennis court and the concrete is 5 m thick mhm underneath there are four big piles 18 M deep and 4 m 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 4 M every 3 days in December 2003 2 years after the construction began the pylons were complete each of these splits in two for the last 94 m 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 [Music] top the entire deck was constructed on the ground in workshops on the plateau's either side of the bridge 150 men aided by robots carried out over a th000 km of welding to assemble the steel roadway 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 M 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 2 cm and as it was no longer resting on the piles it could Advance while 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 cm x 60 cm 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 tailormade lifting system they basically copied the model invented by the Egyptians to raise their obelisks at [Music] Luxor 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 3 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 ja Shak a proud memory for m v what really touched me about the occasion was when President sha got out of his car looked at it and went that was fantastic 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 [Music] recently Engineers have broken new records with its pylon spaced 1,48 M apart the cable stage span record is held by the third Bridge across the Bosphorus designed by Michel Viller in eastanbul and China has recently broken the height record with a bridge culminating at 565 m above the bipen [Music] 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 as suspension bridge with steel cables has its limits the moment it can no longer bear its own wait 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 vrus 2,000 years ago which are utilitas fermitas venas utilitas is usefulness a bridge must have a purpose fitas is resistance a bridge must hold and it must be longlasting and finally venas which is Beauty and elegance [Music] today the world has three Mega skyscrapers reaching over 600 M physical representations of man's Eternal desire to conquer the sky from the Tower of Babel to the birge Khalifa in Dubai the creation of high-rise constructions has been unceasing Richard taer is a physicist he went around the world to research the subject ask the expertise of Engineers and scientists driven by their desire to reach for the [Music] sky how were the Egyptians able to build pyramids that dominated the world for nearly four Millennia what were the methods of Cathedral Builders how did engineers make use of scientific models to design emblematic monuments [Music] Richard T takes us on a vertical journey in the footsteps of those who set out to conquer the sky to understand how over the centuries men have been able to defy and then Master the laws of physics as they build higher and higher [Music] [Music] his investigation of man's race for elevation took Richard T to Egypt [Music] [Music] at the edge of Cairo on the Giza Plateau stand the [Music] pyramids the Pyramid of kufu the largest remained the tallest structure in the world for nearly four Millennia what expertise was available to the Egyptians when they built built these monuments it's a mystery that continues to Fascinate scientists and egyptologists such as Pier t with him Richard T visited the pyramids the last remaining Monument of the Seven Wonders of the World hello Mr T hello so thank you for meeting me here to help me understand the pyramids it's my first time seeing them in real life can you tell me a little bit more about what we see here these are the three Pyramids of Giza the most famous pyramids they're in chronological order the Pyramid of kufu which is the farthest then CF and finally the last one which is much smaller Menor they were built around 2500 BC and how tall is the tallest the tallest kufu is over 146 M High a height never reached by any subsequent pyramid what's really amazing is it steep slope it must be a 45° angle the kufu has a 51° slope with the base of 230 M so it's very Steep and we're a little bit far away but even from here I can see that the blocks are huge how did they move them do we know the question of the physical construction of these pyramids remains open for debate archaeologists believe there were different models of ramps that would have allowed the blocks to be transported these ramps were used with sleds so an inclin plane was used to raise the blocks they're heavy 2 and A2 tons on average really and it is estimated that for the largest of these pyramids kufu it would have taken about 2.3 million blocks to build the whole Monument should we take a closer look of course when observing the pyramids all in a row a striking detail appears their slopes are parallel this is obviously not an accident but a mathematical concept proportion a case study examined by the historian of science Evelyn barban on certain sites it's very easy to see that all the pyramids have the same slope you can see this just by noticing that the edges are parallel so it means that it was planned and we know how based on the idea of proportionality thanks to the ren Papyrus we understand how the Egyptians were able to build the pyramids so that their slopes were identical [Music] we know that the Egyptians had the idea of proportion and used a small triangle using that small triangle told them where to place the next Stone the small triangle and the pyramid were similar triangles as we say today and this similarity is found in all of the pyramid slopes [Music] how can we not wonder what methods were used to build these colossal Stone constructions from the foot of the pyramid we can really see the blocks I mean they're huge people have an image in their head of armies of slaves working on the pyramids is this impression correct not really certain films have popularized the idea of Slave people working on pyramids nothing is further from reality the more documents we find the more we realize that the work was remarkably well organized by the Egyptian monarchy and that the workers were Craftsmen chosen by the king they were well fed well paid and employed on a yearly basis for their skills and according to the American archaeologist Mark Leonard since it took 2.3 million blocks to build the Pyramid of kufu we can estimate that they made an average of 350 blocks a day over the 27 years of kufu Reign a team of 800 men is capable over such a long period 27 years of carving all the blocks that made up the pyramid by making these extrapolations we've concluded that a team of about 5,000 at the most would have been perfectly sufficient to construct the entire building okay that's still quite a large [Music] team the pyramids dominated the world until the middle ages but it was on another continent in Europe that the symbolic 150 M Bar would be crossed when Church belt Towers began reaching for the sky around the year 1000 Christianity's development led to an architectural movement with Romanesque art the desire for height was as much the expression of Faith as a show of power [Music] but the race toward the skies Advanced with the appearance of the gothic style with its broken arches in less than two centuries more than 80 Cathedrals were built in France what challenges did the cathedral Builders face what were their methods to find out Richard T went to notam Dam a remarkable structure in many respects with the greatest interior volume of any french Cathedral hello Risha I know nice to meet you so you're a medievalist historian engineer that's right I don't know if after all these years you're still as a struck as I am but I find it amazing uh never fails to impress each time you look you always discover a detail you've never noticed [Music] so they started construction around 1220 they began erecting a huge Foundation of over 7 meters high it covers the whole surface under our feet and then the Nave was built very quickly all right Advanced Techniques were used to a a this especially the advances brought about by medieval industry with serialization a sort of assembly line approach and you don't necessarily realize when you're inside but it's tall how high is it about 42.3 M so 15 floors yes notam dam was a wildly ambitious project unrivaled at the time one that holds great Fascination for Richard [Music] [Music] T as a physicist when I see the columns the mass that is above us I try to reason in terms of force and mechanics but I imagine that in the 13th century these Notions were not very well known exactly what kind of theoretical tools do they have at the the time for constructing these cathedrals in terms of theoretical tools they didn't have much Mastery of the compass the set Square the ruler very good drafting methods and the right materials they used the right Stone in the right place empirically very empirically just by weighing a stone they knew its density and they put the heaviest stones on the bottom the lighter ones on the top when we make sophisticated calculations today we realize that these structures oversized from today's Viewpoint because they didn't calculate the size at all but pillars like this could beer maybe 20 or 30 times the load they currently carry few or no theoretical tools as for the construction tools like the plum line or the arithmetic rope they remain astonishingly simple in light of the scale and the complexity of these Stone constructions [Music] well let's try one of these so-called rudimentary tools we're going to make a right angle with this rope that has 13 knots 13 knots we're going to make a triangle with one side that's three units 1 2 3 four units here 1 2 3 4 so if we calculate this on paper using geometry a triangle with these proportions should have a right angle here it's the Pythagorean theorem but the medieval Constructors didn't know this theorem however they knew that when a triangle has one side that's three units another four and another five it's a straight line so that gives us a right angle and it can also help to make horizontal [Music] lines if the vertical line here is aligned with this side it means that the bottom is horizontal yes let's try I'm a little intimidated it's my first time using this medieval tool here we go I'm putting it on the surface and yes it's horizontal it's remarkable so I tested the horizontality of this part of the cathedral the builders did a good job we can see that they managed to build something massive and durable using a relatively simple toour and that 800 years later with maintenance it has remained sound but not all cathedrals have been so lucky a few kilometers away sad de B has had a turbulent [Music] history it should have been the high highest cathedral in the world but the Builder's plans were foiled by the laws of physics leaving it unfinished Jean Lucian G is the Heritage officer who watches over it today so we're entering the Cathedral at what should have been the main entrance if the Nave had been built and we can see the size of the aisle and the choir with its Gothic architecture in front of us the bishop of B who decided to rebuild the cathedral in 1225 wanted it to be the most magnificent tallest and largest cathedral in Christendom so the vault is 48 m 50 High the tallest Vault ever built at the time s De B benefited from advanced technology it was reinforced with iron its arches were supported and bound together with metal tie rods but this precaution would prove insufficient the choir suffered some unforeseen events it was completed in 1270 50 years of construction and in 1284 some external flying but es broke causing certain arches to fall it didn't completely collapse but nevertheless as a precaution the Reconstruction included a new column in each span and that's why it's a very small space so three new columns were added in between the 13th century columns all right each Arch is therefore divided in two and supported by an additional column [Music] we're going to see the upper parts of the church now and look at the tie rods more closely the stairs are very steep here we are okay we have a good view here of the cathedral's 13th century architecture and the differences between the original structure and the Reconstruction that took place in the 14th century so we can see this buttress column that is very streamlined but has a large surface area for the wind and then a column here in a cruciform shape that's a little less wide but offers protection in this direction it's really reinforced in all directions so more solid less wind vulnerability more stable yes more stable and if we move forward we see the structure of the ti rods they're iron bars that crisscross they're iron bars that connect everything so that the structure is held together if there's movement okay it keeps everything in place the continuity of the chain is the important thing one wouldn't be enough the evolution of Gothic architecture with its unprecedented successes and spectacular catastrophes is studied in many universities including the United States [Music] Richard T headed to New York he went to meet with researchers from Columbia University who are studying French Cathedrals using modern scientific tools and have created an index of all of them [Music] Steven Murray and Rory O'Neal have developed digital tools to better understand Gothic architecture first off with a huge database called mapping Gothic what's particularly interesting is here it's arranged by Nave height but we can also arrange by approximate construction start okay this shows the height so here we are in the year thousand one can look at the heights of building changing and you don't see a huge amount of difference in them the great great breakthrough of all the cathedrals is not and it was the first building in northern Europe that goes beyond 100 feet in height 1220 and here comes B 1225 why did it happen at that particular moment ex I would suggest the answer is not simple and what you're dealing with um is a period when the clergy the bishop receiving huge amounts of money from agrarian production and industrial production in the cities and mertile exchange so to make a building very tall like Amia or Bo so in other words the technology was possible only uh because they had the resources to do it to experience in real time the challenges of the cathedral Builders Rory O'Neal developed a digital simulation a sort of scientific construction game yeah the relevance here is to build an appreciation uh an intuitive sense of what the builders were uh challenged with uh they wouldn't be sure of how the blocks would behave until they put them up there and so we can put them up there more quickly in this simulation because each block is behaving as it would uh so we have the ability to vary the sizes of the blocks and their configuration in real time as we try to make this structure taller we've got the same outward Force with this trying to fall and pushing these out but because these are taller it's got more leverage to push these things apart okay and so height the Quest for height here is limited to some extent by the ability to Vault the space so what we can do is certainly add more support on the sides more buttressing this holds and this holds okay but this is expensive here we've got a lot more Stone has to be quarried it has to be brought well somewhere in Islamic Builders Came Upon the idea of breaking the arch a broken Arch an and whether or not this was done for aesthetic reasons or structural reasons we don't know however it does help it works because it's bringing the load more directly to the ground and certainly because of the structural benefits we can start going a little higher and try to make this taller and taller at some point this will also failure so everybody stand back uh so here we've got uh a failure of the structure in static loading but as we get larger to hold more congregants a growing city uh we need to come up with some other solution here um what we know as flying buttresses so I think maybe even you could give it a try okay let's go okay it's Richard's turn to try by his hand at cathedral building and to experience The Humbling challenges of the Quest for height I don't want to brag mine's holding ah okay I spoke too quickly it didn't last very long even seismic Engineers today are still learning from these masonary structures because their simulations are not as accurate as the buildings themselves so for the most part seismic Engineers are uh looking at these medieval masonry buildings to learn how to build better [Music] today for several centuries the race for height remained the domain of the Sacred the highest cathedrals in the world M at 161 M and cologne at 157 M both in Germany would only be completed in the 19th century at the beginning of the Industrial Revolution the concept of technical prowess surpassed that of religious will giving new momentum to the conquest for the sky the engineers performed what were miracles for that time exploiting new materials the steel industry was rapidly developing first Iron and cast iron then steel would become the primary Metals used in construction soon the first skyscrapers were born thanks to a tragic incident [Music] in 1871 Chicago was a prosperous city of nearly a million inhabitants when what was later called The Great Fire broke out from October 8th to 10th Flames ravaged the wooden buildings of nearly the entire city 300 people were killed and 100,000 left homeless as terrible as it was the episode paved the way for Chicago's technological Revolution since wooden buildings were now forbidden Architects turned to new materials such as metal and so the first Skys ER was born the home insurance building designed by the architect William learon Jenny he said that his goal was a height to rival the Tower of Babel but apart from the height it was the construction technique that was truly Innovative in traditional masonry the load of the structure is supported by the walls the more height the greater the forces that are exerted hence the need to build thick walls for example a 16-story building in Chicago has walls that are 1.8 m thick at its base but thanks to the invention of the metallic structure buildings were able to become lighter and therefore higher traditional masonry was replaced by a skeleton of metal girds with the framework connected by rivets this supports the weight of the building and allows the entire structure to be lightened considerably [Music] thanks to this new technique man would be able to set new records in its conquest of height there was much new terrain to conquer and soon a rivalry began in the United [Music] States none of this would have been possible without a crucial invention the elevator Alicia Otis an engineer made the discovery around 1850 here it is the test Tower T Tower to find out just how revolutionary his methods were Richard T went to the Odis Research Center in Connecticut 28th floor where he had a historical experience welcome mer I am Rick okay um you'll need to wear a hard hat okay safety glasses how do I look you wonderful well I didn't expect to see a wooden device like this here so that's actually an elevator this is an actual lift in 1853 elevators were used for Freight Goods okay and if the Rope broke the platform with the goods would fall damaging materials being manufactured Elijah Otis who was the building engineer said there has to be a better way how can we prevent the platform from falling so if you look here you can see the spring that came from a wagon okay so he took something that already existed the mechanism that has been used in trains yes and what he developed was an ability to stop immediately the platform falling down if the Rope broke would you like to try yeah let's go here there you go okay so let's raise the platform right so that's pulled these two [Music] in okay here we are we say Cut the Rope the tension will be released it'll push the Paws into the ratchets and we're going to come to an immediate stop 3 2 1 Cut the Rope whoa yeah absolutely so in 1853 when Elijah Otis had his assistant Cut the Rope he daed his hat and said all safe gentlemen all safe four years after this impressive demonstration the first passengers would confidently ride in the elevator that Alicia Otis installed in New York elevators Remain the subject of intense research today but they have allowed since their invention the true conquest of the sky to begin a bitter competition where science clashes with pride [Music] 5 years before the World's Fair which was to Mark the Centenary of the French Revolution Gustav AEL and his Engineers had the idea for a 300 met tower that would represent the country's rediscovered power and demonstrate its technical prowess [Music] hello missan hello Richard it's nice to meet you likewise so you're a specialist of the iron lady here's this beautiful Tower shining under a blue sky on this clear and sunny day which brings out its graphic lines its lightness the structure is 300 M High making it the tallest building in the world when it was built in 1889 it was really a visible marker of the technical and scientific accomplishment of the 19th century and how is the Eiffel Tower designed was it an idea that came from Eiffel or was it a commission made for the exhibition the tower was conceived by two Engineers Emil n and Maurice Klan who brought the idea for a 300 meter Tower to Eiffel in 1884 based on the bridge columns that the company already knew how to build this would of course be both the highlight of the universal exhibition of 1889 and also the great achievement of his [Music] career so now we're at the square Under The Columns we can see that they're leaning inwards how did it stand up before the first floor was built the challenge was to start the tower they began by building foundations and then the slanted columns to hold them up they just used wooden scaffolds the same that were used when building Cathedrals they started with four columns and it Rose from there the critical point was reaching the platform area on the first [Music] floor we shouldn't forget that they were assembling sheets of metal pierced with holes which to be adjusted precisely before putting in the nails down to the millimeter from there it was a kind of giant mechano that could be gradually [Music] assembled in less than two years the tower was built to everyone's [Music] surprise let's go and take a look from above let's go up [Music] here we see the structure really well a view of a void we're in between the second and third floor about 250 M high and we see that there's not much holding the top of the tower there are open work girds in Total the towerway 7,500 tons it's very lightweight for a structure of 300 M but it has been strategically designed to withstand the wind the wind creates pressure several hundred kilos per square meter which could topple the tower so they gave it a slightly curved form which causes the horizontal force of the wind to combine with the vertical force of the tower's weight giving a resulting Force exactly in the axis of the columns so the shape doesn't come from the architect's imagination but from a mathematical calculation the shape comes from mathematics but that's what gives the tower its visual identity precisely because it's inspired by scientific studies and not by the classic rules of architectural composition okay from June 1889 visitors to the tower could safely reach the top thanks to elevators a real technical feat at the time here we go we're going all the way to the top from the second to the third [Music] [Music] floor we have an incredible panoramic view from here to 40 km away it is stunning so in 1889 parisians could come here and see the very same view for the first time they had the chance to go up 300 meters in the sky and it was a real novelty and it wasn't just a small group of people who came but 2 million people and they weren't afraid to climb to the top of this great iron Tower it was a very unusual opportunity they weren't familiar with mountains or altitude a lot of people must have had vertigo but it was also perhaps a way of warding Off Their Fear saying to themselves I'm 300 meters high and I'm safe on this small platform it showed that one believed in the idea of progress which was strongly valued at the time by all of the citizens in any case I feel safe on this platform no problem I'm not afraid of falling [Music] on the other side of the Atlantic with a dream of becoming the capital of the Western World New York began its own race for height it started in 1894 with the Manhattan life insurance building at 100 m high the first real New York skyscraper in a long series that continues to this day [Music] what trials did the engineers overcome to erect these buildings what new techniques did they use Richard T explored New York along with historian mosette broadrick and stopped at one of the city's iconic landmarks the flat iron building it's a very unusual show it's a triangle it's where the Bedrock of Broadway meets the fashion of Fifth Avenue and because of its funny location it got to be known as the flat iron building so it's a building that comes to a point like a ladies iron iron although we might call it a piece of cake yeah a very tall piece of cake but I guess it's not a piece of cake to build up no no no that was a nightmare for engineers to work on the problem they had was the site trying to get the flanges to work in this narrow corner but this is a skeleton steel construction with terracotta fireproof design and cladding so this is a full skyscraper it has all the characteristics that are needed to make what we come to call after the 1880s a full Skyscraper from the early 20th century every Bank newspaper and insurance company wanted its own skyscraper it was a way of gaining exposure for their brand and asserting their reputation with a powerful symbol buildings of greater and greater Heights sprung from the ground until one of them came to dominate the world for quite some time we're on Fifth Avenue 34th Street is here and right up there is the Empire State Building the projected world tallest building for many decades [Music] wow what a beautiful Lobby and what about this picture here W this is wonderful a big image of the building itself there it is a building that sets back under the zoning law of 1916 in a very dramatic fashion in 1916 after 20 years of people arguing about how big these buildings are New York City passed a Zony law which basically says that the building starts with a base sets back at a certain mathematical formula goes up and allows people to still be bathed in light and not feel that they're down in An Elevator Shaft the Empire State Building with its distinctive silhouette is the Ultimate model of the 1916 law and it was built at the Frantic pace of 4 and a half floors per week it was a construction Nightmare and you know it involved riveting huge girds in the middle of the sky looking out on nothing now I don't know whether you've ever seen the oh pictures of the construction workers the thought of it terrifies [Music] me but the special people who do it are Mohawk Indians from Canada and they were able to get out on those girs and do it and this building was finished in 18 months it was finished May 1st the traditional Moving Day in New York City the building was ready on Mayday 1931 the building flopped that initial commercial failure did not however prevent the 381 M High Empire State Building from remaining the tallest skyscraper in the world for four [Music] decades one of the defining features of the Empire State Building is that it is mainly constructed from concrete a 19th century Innovation that gradually came to replace brick and terracotta this material made it possible to reach Heights that were unimaginable even a few years prior along with steel concrete Remains the primary material used in the construction of high-rise buildings today the higher a tower Rises the more it is subject to external forces compression traction bending twisting and shearing exerted mostly by the weight of the structure on itself or by winds exceeding 200 kmph when subject to pressures that are too great Towers can bend to one side swinging back and forth twist in on themselves and end up collapsing so they have to be constructed with materials that can absorb these movements when used alone concrete has considerable compression strength but its T cile strength is low steel is very resistant to traction and compression its physical and mechanical characteristics are the same in all directions it twists elastically Until It Breaks predictably always under the same conditions manufacturers had the idea of adding reinforcements to concrete in order to give it flexion strength so the tensile forces will be carried by the framework thus reinforced concrete was born to make it concrete is poured directly into molds containing steel bars the laders support the concrete and allow it to effectively withstand the forces that act upon it thanks to the advances made in the strength of concrete and also lighter materials and increasingly efficient engineering the race for height gain new momentum in the [Music] 60s the United States popularize the skyscrape but the records They set were soon surpassed by Asia and the Middle East in Asia Shanghai Singapore Taiwan and quala lumur new highrises were erected each day with Hong Kong holding the record with over 1,250 skyscrapers new records were constantly being set the number of skyscrapers grew exponentially it took 135 years to develop 50 super tall buildings uh and super tall we Define as 300 M or above and then the next 50 super tall buildings happened in less than a decade so the pace of development is absolutely rapid and and and massive however we were seen such extremes of height that super tall no longer caught the essence of the extreme height that we were seeing being proposed so that's why we introduced the term megatall which is 600 M and above and right now there are three Mega tall buildings complete around the world the final step of his investigation LED Richard T to Dubai here he visited the tallest building ever made by man the Burge Khalifa 828 M of concrete steel and glass built in just 6 [Music] years what scientific model did the engineers use to design this emblematic Monument this Showcase of modern science Richard T received special permission to witness the internal workings of the skyscraper to discover its [Music] Secrets hello Mr neib I'm very pleased to meet you and have a lot of questions for you obviously in such a large structure I'd imagine that the elevators must play a very important role definitely Richard we have elevator which is the highest travel in world 504 M traveling so let's have this great unique experience traveling at 10 m/ second please be my [Music] guest this is a double deck so double deck elevator is like two cabin on top of each other this is the lower deck and we have the upper deck oh this one here this one here the lower one here correct so we're going to take it up to the 123d floor okay some please [Applause] there are two buttons yeah so button 123rd floor correct so and we'll be traveling around 442 M I can feel the acceleration yes and the total travel takes around a minute until you reach for 442 [Music] M I've never gone as high as 123 flaws in my life please thank you it took less than 1 minute to reach an altitude of 460 [Music] M the highest skyscraper in the world is truly at the Forefront of Technology it is permanently under surveillance from an underground control room that Richard T visited this is the brain of our building the brain okay the Sero from here we get to manage and control and Overlook all the operation of our equipment within BJ Khalifa all the systems that we have in BJ Khalifa are linked to these screens power supply air conditioning the structures movements a close eye is kept on every element to ensure the safety of this vertical City I'm especially interested in this one with the small oscillations khif is the world's tallest building and it is acting like a big sail and we need to always monitor its movement so what you see here is the actual building movement as we speak now as a physicist I'm interested because I see acceleration marked here so these are sensors that measure the acceleration of the tower I imagine you can convert this acceleration into motion into distance that is traveled beyond the equilibrium position uh yes the system has uh the capability to convert this into millimet currently although it's a bit windy outside you can see there is a spikes here and that is in Micron so it is hardly moving abortion of a millimeter it is that St the building is that stable due to wind the building can tolerate a building movement to approximately 2 m to any direction building a skyscraper over 800 M high that can guarantee the comfort and safety of its occupants is a technological achievement its designers had to find solutions to problems that up to that point had only been theoretical when you're designing these very tall towers the main load you have to contend with is wind it's not no dead load which is the weight of the building it's not live load which is the load of the people in the building and the furniture they put [Applause] in people don't realize is and wind goes past an object and if that pulsing matches the natural harmonics of the building you can get quite large forces one of our goals of shaping the building was to get the shape which confuses the wind and the shape of the building at the bottom you'll be going into two wings and by the time you to the top it morphs into a nose like the front of a boat and through this shaping the the wind forces went way way way down the unique layout of the bur Khalifa allows it to divert wind but in structures with more classical shapes there is another way to resist movement even from earthquakes to limit oscillation these skyscrapers have dampers whose principle is simple it's a mass that moves mechanically to the frequency of the Tower with a certain time delay thus helping to stabilize the building there are different kinds of dampers some are made from an enormous concrete block which must weigh at least 100th the mass of the building placed at the top of the tower on a layer of oil and connected to the Walls by Springs the m follows the movement of the building but with a delay due to the oil in the case of the Comcast Center in Philadelphia there is a hydraulic damper containing 1,100 tons of water that moves from one reservoir to another thanks to a motion sensor but one of the most surprising dampers is found at taipe 101 in Taiwan a 508 M High Tower located in a seismic Zone it's a gigantic steel pendulum measuring 5.5 m in diameter weighing 660 tons which can sway up to 1.5 M reducing the building's oscillation by 40% the wind was not the only difficulty the Burge Khalifa had to overcome with construction projects of this scope even when they're extremely well thought out there are always surprises in store and the most unexpected sprung from an unlikely Source the building's own backers the initial design was only 10 m taller than the world's tallest building at the time so it was only 518 M tall but during the design process it grew by 310 M the structure was already up in 35 floors the Emar management heard that some other developers in the area were going to build another tower that was going to be higher than 700 M so everything was kept very quiet but they instructed us to raise the tower height to 8820 m so we all came to the conclusion yes we can increase at way 20 M so the design was changed and um from that period we went on and finished the tower 20 [Music] M on January 4th 2010 Dubai revealed a secret that had been fiercely guarded until then that the Burge Khalifa's final height would be 8 28 M they celebrated the achievement with a spectacular inauguration everybody involved in was very proud and I can say you know a large measure of relief yeah it's like you know there's a big burden taken off your shoulders you can say wow I can relax now and now it's [Music] finished the Burge Khalifa is a skyscraper that has beaten all the records but if it holds the title of highest building in the world for for the moment this will no doubt one day be stolen by another building already the Kingdom tower which is expected to reach 1 kilm is under construction in jeda Saudi Arabia and if man strives to reach even greater Heights will there be physical constraints insurmountable limits the only limit on height until we get to almost unimaginable Heights like several miles stratosphere is financial there is no technological limit to height the Quest for height means ego and attention mankind has this desire to go to the next level to push the limit and the Quest for the world's tallest building has always been a part of that when you go hiking you want to go to the top of the hill to see what's on the other side you know you're walking down the street you want to see what's around the corner uh and so this desire to go high is just it's it's somehow it's in our mythology it's just in our culture why go climb a mountain well we do it's just part of part of Being Human at the end of his journey through space and time tracing the foot steps of those who set out to conquer height Richard T wonders since over the centuries science and engineering have allowed us to constantly push the boundaries of what's physically possible will nothing be able to limit man's Eternal longing to reach for the sky [Music] [Music]
