Singapore's Marina Bay Sands is one of the world's most complicated construction projects engineers have to build not one but three skyscrapers that will shoulder a sky park as big as an aircraft carrier worst case scenario we get stuck they have to devise ingenious solutions to assemble a 60 meter tall Museum of impractical dimensions install giant artworks and erect seemingly floating pavilions for shopping and entertainment if engineers succeed they will create a virtual city unto itself Singapore the Southeast Asian country is smaller than New York City the lack of space forces it to build its largest leisure and entertainment hub to date on a small tract of reclaimed waterfront land the Marina Bay Sands it's not one mega-structure but many serious challenges lie in the array of buildings that form the unique complex 3:57 story hotel towers slope at such great angles they're in danger of buckling under their own weight an even bigger problem is the hotel's roof the 340 meter sky Park spans its length containing Gardens outdoor pools and the world's largest cantilevered observation deck but how do you build something as big as an aircraft carrier 200 metres in the air in the hotel's atrium mammoth works of art have to be somehow incorporated into the architecture it's challenging centerpiece a 15 tonne mass of steel by a renegade artist from Britain a 16 metre tall art science museum is designed for maximum visual impact it will be to Singapore what the Opera House is to Sydney only one problem it seems too impractical to construct and a set of dramatic glass encased pavilions while themselves pose little challenge have to be built in water the man behind the Marina Bay project understands the risks but he believes that anything short of astounding will fail sheldon adelson one of the world's richest men and CEO of Las Vegas Sands corporation what we hope to accomplish is to change the face of Singapore tourism so we expect a very successful development that is by far the largest most expensive single project we've ever undertaken it'll cost about five to 5.5 billion US dollars it's a lot of money now I know a billion dollars doesn't buy what it used to but by any measurement it's a lot of money today Adelson believes his huge investment is safe in the hands of Moshe Safdie a world-renowned architect Safdie is recognized for his use of dramatic curves and geometric patterns the Marina Bay complex will be his largest and most difficult project yet I think that the architecture has to be timeless therefore what it espouses what it provides needs to be something that has a long life what you think about Marina Bay is all the pieces coming together you can't think about it as individual buildings they've got to think about it as a piece of City it's much more a symphony than it is a Sinatra on the ground engineers are more concerned about the reality of building Safety's vision this is the North retail section area 30-year veteran John Downes is in charge of overseeing the entire project the design is very very diverse and each component of the project is totally different from the others the project of this size you'd expect with the planning with a design with a construction buicks be expecting somewhere between six to seven years here is basic a three-year turnaround the first and most critical construction task is to secure the footprint though this normally straightforward job proves otherwise since the site was originally allocated for boats the complex sits on 560 thousand square meters of reclaimed land part of a decade-long plan to revamp Marina Bay a former saltwater history that's now a freshwater reservoir beneath the reclaimed land which is essentially a seabed is a dangerous layer of marine clay sometimes called black toothpaste marine clay has very poor structural properties if not given complete respect the unstable marine clay is potentially fatal in 2004 Singaporeans discovered the lethal consequences firsthand a routine excavation in an underground tunnel for the mass rapid transit network causes a collapse creating a gaping hole in the nickel highway killing four workers the ground conditions in which they were building the nickel Highway were not dissimilar to those in which we are encountering here they had also soft clay that they had similar depth of excavation between twenty and thirty seven meters one of the big things that was learnt in the nickel Highway collapse was the importance of monitoring movements and the control of quality as the construction proceeds Marine clay is an old foe of engineer Mike Barton he's defeated it in the past by understanding how it behaves the big problem with marine clay is that it is so soft that when you dig out the inside that walls will move and potentially collapse and allow all the surrounding water in the bay into the excavation so before work can begin the unstable building site needs major fortification to combat marine clay engineers decide to build giant concrete walls to create stabilizing perimeters for the larger buildings known as diaphragm walls up to 1.5 meters thick diaphragm walls are steel reinforced concrete sections found at 50 meters into the ground they form watertight enclosures for men and machines to work round the clock in just one year over 4,000 metres of diaphragm walls help produce a rock-solid foundation the diaphragm walls that we constructed in a formation which we called a peanut formation which is two circles joined together and a donut formation which is circular is that they are able to withstand very very large forces from the marine clay without any movement they encapsulate an area that's bigger than a football pitch that enables us to excavate very quickly and to build structure up very quickly securing the footprint of the Marina Bay project has already taken a year out of John down schedule he now faces the difficult task of erecting the resort's many buildings in a space of just two years just managing the whole logistics of that including the construction methodology is very very challenging for us to meet his tight deadlines Downs chooses the most direct solution the highest 16,500 workers to construct every single building simultaneously it's like leading a small army so organizational excellence is key we're just on the edge of Singapore and the CBD here so rather than lose the contractors and the workforce to go off-site we've built our own three-story project office we have all of our contractors or subcontractors here we have our resident site staff we have our project management team we have our construction management team their design management team and the logistics here the tight schedule also creates problems at the hotel towers where engineers are already struggling with a congested site the important thing to do is to make sure that they come in and deliver the goods straight away and then get out again we don't want too many vehicles on site at the same time to speed up construction and alleviate traffic congestion engineers turned to a method that's proven itself countless times in the field in situ concrete casting hotel walls are made on-site in the thousands and workers laying the floors are so proficient they produce one floor per four-day cycle it's an impressive display for a conventional solution but the structure they're attempting is anything but conventional the key challenge of building the hotel Towers is his unusual design unlike other skyscrapers part of the towers sloped at incredible inclines like a set of collapsing dominoes the towers could buckle under their own weight if a practical building solution is not found it's a major concern for engineer Craig Glover I've been in the industry for 25 years done a wide range of projects in many different countries but nothing compares to this whatsoever there was nothing we could take reference from across the street on the next high rise or across town this is a new frontier costing is staggering 5.5 billion dollars to build the Marina Bay Sands could be one of the world's most expensive mistakes if engineers can't solve the towers problematic structure engineer vici Chong leads the design team and their solution comes out of left field if you look at a configuration it's not a strict our is if it's nothing like so all this flopping neck actually is you know inducing a very huge external force onto the structure we kind of built it we've done in the support so we actually formulate absolution to prop up the sloping edge using a technique they've never employed before engineers build large temporary struts made of strong structural steel they prop up the sloping towers as they rise like a suspension bridge high tensile steel tendons also known as tension cables give an added layer of support inside the walls in theory both the struts and the tension cables are temporary then will be removed once join link trusses connect the towers at the 23rd floor the sheer weight in concrete is enough to topple the towers at level 8 if the engineers calculations are wrong to reduce the chances of failure Glover and his team make a radical decision instead of removing the temporary tension cables in the tower walls they make them permanent supports I feel good it's in there because it's added strength it's added support we have a twined a network here of high-strength steel and what we do is we bundle these up so they form a cord with multiple strands inside this conjurer we place this conduit inside the walls try to Casting the concrete so what we then do is once the concrete is cast we anchor one end into the concrete so we then put a very high strength pneumatic jack onto the collar and one by one pull these strands through and tension them up what that does is basically pull the building back and hold in place if these cables were to suddenly break or if they weren't in place we wouldn't be able to control the self-weight as we build more and more of the building up despite the team's quick thinking the true test of their engineering decisions will only happen once the main support struts are removed and the massive link truss is installed linked trusses a huge reinforced steel brackets that bind the towers at the 23rd floor once the installation is complete they transfer the sloping towers weight completely away from its temporary struts hydraulic cranes in bestop this mandala struts got a lot of time pressure so we're just got to make sure that these things keep moving as the last pieces of support struts leave the site Glover and his team can finally breathe a sigh of relief the link trusses are holding the building load so far so good not all the structures have ended up according to plan the 60 meter high art Science Museum is facing a major design overhaul planned as a venue for blockbuster exhibitions on the arts and sciences its bowl-shaped roof doubles as a 3,000 seat amphitheater unfortunately for engineers eager to start its construction architect Moshe Safdie isn't happy with its current shape somebody looked at them and said there looks like a bunch of bananas in fact mr. Adelson said looks like a bunch of bananas I said well if they looked like a bunch of bananas we're not there yet it's terrible news for safdie's design team especially its principal Jean Dyer there are times that motion will come in with an idea we think it's quite exciting we'll pursue the idea for weeks or even months he'll come back and say I want to change the idea and we've already bought into the idea what's bit frustrating to rework the unique geometry and dimensions of the art Science Museum daya and his team turned to advanced 3d modeling programs it not only makes navigating the museum's complex geometric patterns easier it shortens the process to a matter of days the model is dynamic and it can be moved by just changing one or two elements motion could experiment they can make rapid judgments in very short period of time about which way he wanted to take the project this is a process that was impossible to do ten years ago without the computer this would take years and years and years after months of refining the design safty is finally happy with the result its mathematical precision that we gave them made them even more beautiful it led some people to say well hand of welcome other said is added Lotus and the more ambiguously associations the closer I thought we were getting to our target because I think the least exciting building are those which have overt symbolic association armed with the new design engineers begin work on the museum 16 meter high superstructure a staggering 5,600 steel elements weighing some 5200 tons a prefabricated to exact specifications they are then trapped onto site and assembled it's like putting together a giant jigsaw puzzle each element has to be installed with pinpoint accuracy if it's even a few millimeters off engineers will have to start from scratch engineers of the massive atrium at the base of the towers are facing an equally tough construction process Safdie has come up with a challenging design he wants to inject art into the atriums architecture so that visitors will feel like they're walking through a grand Gothic cathedral in medieval times if you think of a Gothic cathedral does the architecture there's the stained glass windows visitor sculptures on the pinnacles you cannot draw a line and say arts and architecture art and architecture are wander singular experiences and I think what we try to do is come back to this integrative mode to create the centerpiece of his vision for the atrium Safdie commissions renowned British sculptor Antony Gormley famous for his unusual approach to art Gormley is the brains behind the angel of the north sculpture in northern England what he's about to attempt is proving to be more of a construction challenge than an artistic one a cloud-like sculpture some 40 meters long made up of 15 tons of high-grade stainless steel hung 12 stories above the atrium the Angel of the North is in a way making a very traditional public sculpture because it's isolated in space at the edge of a valley you can see it for miles and miles it's very much about occupying space this is about activating space but just as they're about to begin construction a bombshell drops September 2008 a global financial crisis wrecks havoc on markets the flow of the hundreds of millions of dollars that keep the Marina Bay project going every month suddenly stops for engineer Matthew Pryor it's a massive blow I feel devastated which couldn't be worse probably the worst day of my life professionally there's no more money coming through so unless we put some funding in place or there's something we're gonna have to shut the jobs down there's a tough decision tonight and we don't know what we're gonna do just at this point in time with the future of the multi-billion dollar project plunged into doubt all eyes turned to the man behind it sheldon adelson the next move of one of the world's richest men will determine the fate of the mega construction site the 2008 global financial meltdown is a haunting echo of the 1990s Asian crisis back then progress on Shanghai's world financial center came to a complete halt for five years for Adelson that's simply not an option for the high-profile Marina Bay Resort his vision of changing the face of Singapore tourism is at stake and so are billions of dollars of investment from his Las Vegas Sands corporation he prefers finding a stopgap solution to weather the storm throughout history there has never been a trend that went straight up no trend there one straight down so it goes up and down at Sonia it's only a matter of time when things will be done in a bold move Adelson pledges his vast personal wealth to the completion of the project effectively ending any speculation of failure it's a massive sense of relief in the company of anyone pleasantly surprised how quickly we've got through this and the fact we could hold it together and get either going again so before is probably the best best way to describe this with the crisis averted construction on the 357 story hotel towers the casino theaters and Convention Center resumes it pace everywhere you turn steel is being installed it's vital reinforcement for every concrete structure on the 15.5 hectare site for one project at the tower's atrium steel is more than just reinforcement to construct the 15-ton drift sculpture by British artist Antony Gormley engineers had to first laborious leap refabricate it into over 70 segments the segments are then welded into 8 slices and will ultimately form the sculpture it's a tricky operation but engineers are able to complete it swiftly due to a system of codes and numbers that enable them to quickly identify what goes where once all eight slices of drift are fully assembled its lifted up into position by a temporary lifting frame a massive box trusts on the atrium ceiling then takes over the load in theory the box trusts will support the weight of the lifting frame as it's being lowered down it will be a hard stopping moment especially for engineer Graham Stevenson the lifting frame is about nine and a half tons so when it picks up and gets some momentum there's a potential that it just wants to flick over and I'm rotate through it's full 90 degrees and we won't have it under control Stephenson's solution for powerful automated hoisting drones located at the four corners of the frame they allow workers to control the strength and speed of the operation with high tensile steel cables a spotter at the top determines the pace of the procedure and marshals the team the entire operation is estimated to take up to ten hours to complete as soon as the frame is in motion there's no turning back midway through the lift Stevenson receives reports of a potential problem when we do story number seven temporary kappa scaffolding to achieve a cable that definitely cable-less into the transfer is it just the end with you yeah you can just come true yeah problem solved but what was previously an estimated ten hour procedure now turns out to be a 24 hour marathon lift at 6:00 a.m. the following morning they complete the job absolutely fantastic the gum is now finally in its final position so really an end of a long and exhausting day and big thanks to everybody but it's finally done while the drift settles into its new home at the hotel atrium elsewhere attention is focused on one of the project's key features the Crystal pavilions the - glass encased buildings by the promenade are set to be the resort's premier shopping and entertainment complexes but before engineers can make them a reality they have to secure their footprint and already a major obstacle threatens to sink their objective the Crystal pavilions are situated within the confines of Marina Bay so to found it Engineers have to find a way to build in six meters of water the responsibility of tackling the problem falls on the shoulders of engineer Kurt feller I'm from Sydney the underlying the foundation in Sydney is this sandstone it's it's rock all's you need to do is just dust off the surface and you can build skyscrapers on it here is very different all the structures have to be heavily founded to keep water out of the construction site only one solution seems viable for Vella and his team a waterproof steel structure called a cofferdam this temporary formation surrounds the work site with a circle of steel sheet piles creating an impenetrable shield that locks out the water keeping the workers safe within for the job they rope in a 12 tone vibro hammer it punches the sheet piles deep into the earth making the cofferdam rock solid and resistant to movement with a cofferdam secured Engineers deploy powerful diesel pumps and run them 24 hours a day ejecting any water that remains within the walls this last step comes with inherent dangers the force of the water outside creates what engineers call hydrostatic pressure in theory it's powerful enough to force water through any gaps in the cofferdam it's something that valour praise will not happen there's a bit of hesitancy and concern because only we've got a bilbies building in the middle of Marina Bay everybody can see what we're doing so if it leaks it's a problem that it fails if it moves if it collapses it'll be an absolute catastrophe after a day of pumping Valis worst fear comes true parts of the cofferdam are leaking to rectify the problem in valor orders a team of eight divers into the water on 10-hour shifts their mission find out where the water is being forced in and plug them shut with epoxy resin Anson Lee is an eight-year diving veterans power Joe is going - the V jerky is foyer is totally zero across the interior you know I stopped that by peeling here the suction and HBO you have to overcome on the field I can see under the water but yeah I feel proud will be one of this team to do this thing our after two weeks of hard work by divers and the pump crew the job is finally complete after two years of battling the elements and overcoming difficult construction milestones the three sloping towers of Marina Bay Sands can finally celebrate their topping off ceremony and move on to the next phase but a destructive force of nature threatens to throw a spanner with climate change predicted to effect the pattern of Southeast Asia's typhoons Singapore may one day experience the destructive tropical storms plaguing as northern neighbours in the Philippines and Taiwan when that happens typhoon force winds could spell disaster for the hotel towers especially the 340 meter sky park sitting on top of it the force of the wind can make both buildings sway dangerously causing irreparable damage to the structures the sky park offering 360 degree views of Singapore the visionary design will have enough surface area to park four-and-a-half Airbus a380s but when architect Moshe Safdie first mooted it it stemmed from a purely functional need luxury hotels as we think of them always have lots of open space around them Gardens at least in the kind of tradition but we didn't have much space left and at that point I figured well if we cut out of a extrusion of foam they kind of slab that goes over those three towers and we placed it there with him what are we having it my god that's some power and so that's where the idea was born that's what makes us a resort safdie's revolutionary idea scores points for ingenuity but it clearly isn't what nature intended typhoon force winds threatened to rock the towers and it's SkyPark causing unimaginable damage if engineers are to make the building a reality they'll need a rock-solid solution engineer Tony McKee has little time to make things happen at the moment we're running a couple of weeks behind what we'd originally planned we're not entirely happy about it but at the end of the day we've got to do this safe and we've got to do it properly to fight the enemy McKee knows he has to first understand the enemy he hires leading us wind engineers cpp to carry out extensive testing on the towers and SkyPark their mission find out how Singapore's potential wind forces affect the building's wind engineer Roy denoon oversees the process at their state-of-the-art wind tunnel in Fort Collins Colorado the thing that makes this really special is the fact that we have the sky part running across the top linking all the terrors together so whereas normally with a normal terror we'd measure the loads on the terror in isolation with this one what we're needing to do is to measure the loads and all three of the terrors at exactly the same time so that way we can know how the towers are going to move relative to each other so we can make sure that they're not going to put excessive strains or movements into the sky part during the tests a scale model of the Marina Bay Towers is blasted with 40 kilometer per hour winds to simulate faster typhoon winds in reality over a thousand pressure measuring instruments inside the model register how the winds affect the buildings at the end of the tests engineers confirm that the three towers can deform by some 200 millimeters during the fiercest storm engineers quickly figure out a solution movement joints inspired by bridge engineering philosophy movement joints are essentially gaps located between the concrete towers the huge gaps allow for movements of up to 250 millimeters aluminum and stainless steel plates act as sliding components they can move back and forward over each other a little bit like you'd see in a flexible bus where you have that articulation happening in the middle it's it's a similar concept to that to accommodate the differing movements of the three towers engineers install multi-directional steel bearings below the sky Park armed with the final results McKee can now safely begin construction of the sky park consisting of some 10,000 tons of steel the SkyPark is as big as an aircraft carrier the most practical way for engineers to construct it is to break it into 14 segments on the ground before assembling it at the top of the towers there's no room for miscalculation at 200 meters in the air each segment is carefully prefabricated and tested by steel specialists young-nam and then trucked to the site independently from the very beginning McKee and his team anticipate that their biggest challenge will be lifting the two largest segments of the sky pop the box girders measuring eighty meters long their combined weight is a staggering 1400 tons how do we feel a little bit of apprehension you know it's it's a significant lift that hasn't been done before if something goes wrong it could be really significant for us to reduce risks McKee turns once again to proven bridge-building technology in a process known as strand jackin giant temporary lifting gantries made of strong structural steel will use powerful hydraulic jacks to lift the box girders up to the top of the towers before sliding them into place it will be the longest and largest lift of its kind in the world and the key needs the best in the business he puts a pioneer in the field in charge Swiss French company fee is healthy engineer Eddie King and his team have successfully raised bridges stadium roofs and even Ferris wheels the toughest work of my work is you have to plan it everything very precisely because everything to setup in millimeters so we have to leap up and slide it in and position it in five or ten millimeter accuracy we don't do properly or don't do safely here was the biggest hazard if the thing can fall down to the ground other factors further complicate the lifting process due to an increasingly tight schedule the team is forced to conduct the lift during Singapore's annual monsoon season it's almost impossible to predict when a tropical storm will hit when it does the accompanying lightning strikes can endanger lives and because the whole operation takes place meters from a jam-packed highway curious onlookers will be able to see any mistakes the engineers make it's a potential public relations nightmare during an estimated 16 hour lift the box girders will move at a cautious 14 metres per hour Eddie King and his team constantly checked their weather gauges for any incoming storms the hydraulic jacks are also inspected regularly for overheating no one wants the operation to stall in midair other one that this one here despite the team's best efforts mother nature catches them by surprise hey guys rains coming and approaching downpour threatens to grow into a lightning storm yeah underneath Appa and surrounding building is quite far away there's a chance of the I think striking on the high point like this we gotta stop and wait until the weather getting better before we continually Maki's worst fear comes true if the girders remain stuck at Midway for too long he will have to order them down okay laughter attends three hours the Lightning threat passes and the operation cranks back to life by the time the box girders slide into position it's past midnight we hope tomorrow we can with the lessons learned from the box girder lift the rest of the segments go up smoothly as the final piece Rises into place Singapore is already marveling at the team effort behind one of the world's most ambitious building projects in just three years engineers overcame seemingly impossible construction challenges defeated marine clay engineered ingenious design solutions and survived the most debilitating financial crisis since the 1930s as the finishing touches are put on the resort the stage is set for an opening party Singapore style those involved reflect on the project that has already far surpassed their expectation it's a bit kind of overwhelming you know what I'm in the process of disconnecting the umbilical cords very not easy for an architect this type of project Koby any comes around every 25 years or so so it's it's been a lot of hard work extremely challenging I really can't imagine I couldn't list the number of challenges we've overcome along the way to get to today everybody is saying this is kind of a miracle huh you know never seen anything like it and it's rewarding it's nice the Marina Bay Sands Singapore proof that with visionary design and engineering know-how megastructures can still defy the odds and fulfill the wildest dreams
