1 00:00:01,034 --> 00:00:02,912 [Male Narrator] What happens when 41 stories 2 00:00:02,936 --> 00:00:07,083 of radically futuristic design reshapes one of the world's most 3 00:00:07,107 --> 00:00:10,619 recognizable and historic skylines? 4 00:00:10,643 --> 00:00:14,523 I was described as public enemy number one. 5 00:00:14,547 --> 00:00:17,026 [Narrator] How do you build a record-breaking bridge 6 00:00:17,050 --> 00:00:18,828 without foundations? 7 00:00:18,852 --> 00:00:21,564 These are the kinds of problems that keep bridge engineers 8 00:00:21,588 --> 00:00:23,232 up at night. 9 00:00:23,256 --> 00:00:25,167 [Narrator] And where do you begin with a gravity defying 10 00:00:25,191 --> 00:00:28,070 cloud of glass and steel, 11 00:00:28,094 --> 00:00:31,741 described as architectural chaos? 12 00:00:31,765 --> 00:00:33,342 [Wolf] We can build everything 13 00:00:33,366 --> 00:00:38,204 and not in the stupid way of doing boxes. 14 00:00:40,540 --> 00:00:43,819 [music] 15 00:00:43,843 --> 00:00:48,848 [Narrator] This is the age of the extraordinary. 16 00:00:49,416 --> 00:00:51,761 [Haley] It's like one of those insect eating plants, 17 00:00:51,785 --> 00:00:54,296 only enormous and white. 18 00:00:54,320 --> 00:00:56,399 [Narrator] Where ingenious engineers have unleashed 19 00:00:56,423 --> 00:00:59,368 unchecked creativity. 20 00:00:59,392 --> 00:01:02,872 Now their secrets are revealed. 21 00:01:02,896 --> 00:01:07,276 As we discover the inside stories of their construction. 22 00:01:07,300 --> 00:01:12,071 This is an incredible feat of planning and engineering. 23 00:01:13,339 --> 00:01:16,318 [Narrator] To try and understand, 24 00:01:16,342 --> 00:01:18,611 "How Did They Build That?" 25 00:01:20,580 --> 00:01:23,392 For our first building we're heading to England where 26 00:01:23,416 --> 00:01:27,163 in 2001, one of the world's most celebrated architects 27 00:01:27,187 --> 00:01:29,165 set out to create an extraordinary building 28 00:01:29,189 --> 00:01:31,867 that would change the London skyline forever. 29 00:01:31,891 --> 00:01:34,303 With the address 30 St. Mary Axe 30 00:01:34,327 --> 00:01:38,908 it clearly needed a snappy nickname like the rocket. 31 00:01:38,932 --> 00:01:40,176 No, no, no. The cigar. 32 00:01:40,200 --> 00:01:43,045 No Jay. I know what we'll call it. 33 00:01:43,069 --> 00:01:44,871 The Gherkin. 34 00:01:47,540 --> 00:01:50,243 [Narrator] The City of London. 35 00:01:51,144 --> 00:01:54,323 Home to the Bank of England since 1694 36 00:01:54,347 --> 00:01:58,251 and a financial powerhouse ever since. 37 00:01:58,751 --> 00:02:01,030 It's known for its traditional values 38 00:02:01,054 --> 00:02:05,692 and until 20 odd years ago, its traditional architecture. 39 00:02:05,925 --> 00:02:08,437 It's really hard to imagine now, 40 00:02:08,461 --> 00:02:10,372 but apart from the Lloyds building 41 00:02:10,396 --> 00:02:13,976 that financial district of London was architecturally 42 00:02:14,000 --> 00:02:16,479 really quite dull. 43 00:02:16,503 --> 00:02:19,014 [Narrator] Then at the very end of the last century, 44 00:02:19,038 --> 00:02:22,418 the opportunity arose for a visionary architect 45 00:02:22,442 --> 00:02:25,612 to change all that 46 00:02:26,980 --> 00:02:30,159 with a building that would drag the city kicking and screaming 47 00:02:30,183 --> 00:02:32,886 into a new millennium. 48 00:02:33,253 --> 00:02:35,197 No one has ever seen a building this shape 49 00:02:35,221 --> 00:02:38,000 and size anywhere in the world. 50 00:02:38,024 --> 00:02:41,637 [Narrator] 41 stories of cutting-edge glass and steel 51 00:02:41,661 --> 00:02:44,039 that was ruffling feathers before it was even 52 00:02:44,063 --> 00:02:46,041 off the drawing board. 53 00:02:46,065 --> 00:02:49,512 [Lord Foster] In the opinion page of a prominent newspaper, 54 00:02:49,536 --> 00:02:53,506 I was described as public enemy number one. 55 00:02:54,040 --> 00:02:56,619 [Narrator] An extraordinary concept that forced engineers 56 00:02:56,643 --> 00:02:59,088 to use techniques never before tried 57 00:02:59,112 --> 00:03:02,057 in a building of this kind. 58 00:03:02,081 --> 00:03:05,528 This is 30 St Mary Axe. 59 00:03:05,552 --> 00:03:09,289 Controversial, iconic and one of a kind. 60 00:03:09,923 --> 00:03:12,868 It transformed the skyline of London forever 61 00:03:12,892 --> 00:03:16,596 and challenged engineers to redefine the possible. 62 00:03:17,497 --> 00:03:19,966 So how did they build it? 63 00:03:20,733 --> 00:03:23,612 It's 1992, and a terrorist attack in the heart of the 64 00:03:23,636 --> 00:03:29,442 city of London provides an unlikely catalyst for change. 65 00:03:30,343 --> 00:03:32,021 A bomb is set off by the provisional 66 00:03:32,045 --> 00:03:33,923 Irish Republican Army 67 00:03:33,947 --> 00:03:39,929 killing three people and injuring 91 others. 68 00:03:39,953 --> 00:03:42,131 It damages the Baltic Exchange, 69 00:03:42,155 --> 00:03:44,967 a trading hall that had been at the heart of the city 70 00:03:44,991 --> 00:03:47,970 for nearly 100 years. 71 00:03:47,994 --> 00:03:50,072 The decision is taken to allow something 72 00:03:50,096 --> 00:03:52,932 much bigger in its place. 73 00:03:55,802 --> 00:04:00,883 Norman Foster, one of the world's most famous architects. 74 00:04:00,907 --> 00:04:04,720 Responsible for the Millau viaduct in France, 75 00:04:04,744 --> 00:04:07,489 and the Hearst Tower in New York, 76 00:04:07,513 --> 00:04:11,985 takes up the challenge of redefining London's skyline. 77 00:04:12,685 --> 00:04:16,065 [Lord Foster] Can it give something back to the city 78 00:04:16,089 --> 00:04:19,134 of which it's a part? 79 00:04:19,158 --> 00:04:23,372 In each of these buildings. They interact with the city. 80 00:04:23,396 --> 00:04:26,976 They try to give something back to the public, 81 00:04:27,000 --> 00:04:30,446 as well as creating something very, very special 82 00:04:30,470 --> 00:04:33,515 for the private spaces within the building. 83 00:04:33,539 --> 00:04:35,751 [Narrator] What Lord Foster has planned for the site 84 00:04:35,775 --> 00:04:39,288 takes special to a whole new level. 85 00:04:39,312 --> 00:04:43,225 A 180-meter tall, 57-meter-wide tower 86 00:04:43,249 --> 00:04:45,527 completely in the round. 87 00:04:45,551 --> 00:04:48,030 In order to reduce the impact at the ground, 88 00:04:48,054 --> 00:04:49,932 it will get wider as it goes up 89 00:04:49,956 --> 00:04:53,836 before being topped with a dome of glass. 90 00:04:53,860 --> 00:04:57,272 An interlocking gridshell of two-story-high steel columns 91 00:04:57,296 --> 00:04:59,975 will interconnect at 18 different points 92 00:04:59,999 --> 00:05:02,544 every other floor. 93 00:05:02,568 --> 00:05:04,613 It will then be covered in an intricate skin 94 00:05:04,637 --> 00:05:09,809 made up of 7,492 panes of glass. 95 00:05:12,445 --> 00:05:14,323 In an incredibly high-tech world, 96 00:05:14,347 --> 00:05:18,694 here windows will simply open and close with the weather. 97 00:05:18,718 --> 00:05:21,030 The passive cooling system will circulate air 98 00:05:21,054 --> 00:05:22,898 through the building, 99 00:05:22,922 --> 00:05:25,634 cutting down on air conditioning, 100 00:05:25,658 --> 00:05:29,562 and giving it some seriously green credentials. 101 00:05:35,268 --> 00:05:39,448 The Gherkin was an object of derision. 102 00:05:39,472 --> 00:05:44,820 I think the name Gherkin originally was hostile. 103 00:05:44,844 --> 00:05:48,290 In the opinion page of a prominent newspaper, 104 00:05:48,314 --> 00:05:51,851 I was described as public enemy number one. 105 00:05:52,685 --> 00:05:54,963 [Narrator] Despite the press being against the building, 106 00:05:54,987 --> 00:05:57,966 in 2000 and with some trepidation, 107 00:05:57,990 --> 00:06:01,537 the planning committee grants permission to go ahead. 108 00:06:01,561 --> 00:06:02,805 A year later, 109 00:06:02,829 --> 00:06:06,099 the construction teams break ground. 110 00:06:07,266 --> 00:06:09,278 Arriving here and seeing the 111 00:06:09,302 --> 00:06:12,881 enormity of the task was inspiring. 112 00:06:12,905 --> 00:06:15,217 You really felt like you were getting involved 113 00:06:15,241 --> 00:06:19,021 with something that was going to be out of this world. 114 00:06:19,045 --> 00:06:23,492 [Narrator] The first challenge is to lay the foundations. 115 00:06:23,516 --> 00:06:26,795 [Ellie] The base of the Gherkin is remarkably small, 116 00:06:26,819 --> 00:06:29,098 but because it swells as it rises, 117 00:06:29,122 --> 00:06:33,602 what you get is a very large building with a very small 118 00:06:33,626 --> 00:06:36,505 ground-level impact. 119 00:06:36,529 --> 00:06:39,074 [Narrator] It also creates a serious challenge 120 00:06:39,098 --> 00:06:42,044 because it means the entire weight of the large building 121 00:06:42,068 --> 00:06:46,181 is concentrated onto the small footprint. 122 00:06:46,205 --> 00:06:48,183 Unable to spread the weight out, 123 00:06:48,207 --> 00:06:52,054 the engineers have to create some heavy-duty foundations to 124 00:06:52,078 --> 00:06:56,525 keep the building from sinking into the soft London clay. 125 00:06:56,549 --> 00:06:59,128 Here you want to make sure foundation's sound. 126 00:06:59,152 --> 00:07:00,863 People think that the building, 127 00:07:00,887 --> 00:07:03,766 that the bits they see of the building is complicated. 128 00:07:03,790 --> 00:07:05,801 There's an awful lot in the ground 129 00:07:05,825 --> 00:07:09,738 that's similarly complicated that you will never see. 130 00:07:09,762 --> 00:07:12,808 [Narrator] The team starts by drilling piles. 131 00:07:12,832 --> 00:07:15,043 These underground columns measuring about 132 00:07:15,067 --> 00:07:19,815 five and a half miles in total will hold the tower up. 133 00:07:19,839 --> 00:07:23,786 Each has to be engineered to within an inch of its life. 134 00:07:23,810 --> 00:07:28,690 The load was designed for 117 thousand tons. 135 00:07:28,714 --> 00:07:31,860 We drilled 333 piles into the ground. 136 00:07:31,884 --> 00:07:34,096 Collectively, that's nine kilometres 137 00:07:34,120 --> 00:07:35,798 of straight shaft digging. 138 00:07:35,822 --> 00:07:39,034 The London clay, it gets harder the further you go down. 139 00:07:39,058 --> 00:07:40,569 And when I say hard, 140 00:07:40,593 --> 00:07:42,437 it's like steel when you hit down on the bottom. 141 00:07:42,461 --> 00:07:45,407 It is that hard. 142 00:07:45,431 --> 00:07:46,975 [Narrator] With the piles drilled, 143 00:07:46,999 --> 00:07:50,212 the team plans to finish the foundations with a massive 144 00:07:50,236 --> 00:07:52,648 eight-feet deep concrete slab 145 00:07:52,672 --> 00:07:56,118 connecting all 333 piles together. 146 00:07:56,142 --> 00:07:58,754 It's absolutely crucial that the entire slab 147 00:07:58,778 --> 00:08:01,323 cures at the same time. 148 00:08:01,347 --> 00:08:05,861 No mean feat when you're pouring this much concrete. 149 00:08:05,885 --> 00:08:08,063 You could end up with the bottom of the pile cap 150 00:08:08,087 --> 00:08:13,035 curing before the top and it's not bonded together. 151 00:08:13,059 --> 00:08:14,970 And that's not good. 152 00:08:14,994 --> 00:08:18,540 [Narrator] The entire pour has to happen in one go. 153 00:08:18,564 --> 00:08:21,410 And the concrete is specially treated to make sure none of it 154 00:08:21,434 --> 00:08:25,480 cures till the last lot goes in. 155 00:08:25,504 --> 00:08:27,716 There's an additive added to it, 156 00:08:27,740 --> 00:08:30,219 which made sure that the first lot that got poured didn't 157 00:08:30,243 --> 00:08:33,188 harden until the top part has. 158 00:08:33,212 --> 00:08:36,225 So the whole lot could go off as one piece. 159 00:08:36,249 --> 00:08:39,628 We had three concrete pumps, delivery pumps 160 00:08:39,652 --> 00:08:41,830 situated on three of the corners 161 00:08:41,854 --> 00:08:45,200 and we had 27 concrete trucks on turn around, 162 00:08:45,224 --> 00:08:47,069 bringing this concrete in 163 00:08:47,093 --> 00:08:50,172 from three different depots around London. 164 00:08:50,196 --> 00:08:55,110 So it was a military maneuver that took just over 12 hours 165 00:08:55,134 --> 00:08:59,238 of one continuous pour. 166 00:09:00,072 --> 00:09:02,351 [Narrator] The crew pours over 63,000 167 00:09:02,375 --> 00:09:04,453 cubic feet of concrete. 168 00:09:04,477 --> 00:09:09,949 But with meticulous planning, it goes without a hitch. 169 00:09:11,651 --> 00:09:13,929 Now with a solid base to build from, 170 00:09:13,953 --> 00:09:16,932 the engineers get to work on the complex steel structure 171 00:09:16,956 --> 00:09:19,167 that will hold the building up. 172 00:09:19,191 --> 00:09:21,837 It's known as a diagrid. 173 00:09:21,861 --> 00:09:25,040 The diagrid frame is a network of triangles, 174 00:09:25,064 --> 00:09:27,609 which are also hugely strong and efficient, 175 00:09:27,633 --> 00:09:29,077 but it also gives the building 176 00:09:29,101 --> 00:09:32,981 that unmistakable trademark skin. 177 00:09:33,005 --> 00:09:36,385 [Lord Foster] The Gherkin and the Hearst Building in New York, 178 00:09:36,409 --> 00:09:40,722 when you look at them, they both have triangulated structures. 179 00:09:40,746 --> 00:09:45,827 Why? Because a triangulated structure is inherently 180 00:09:45,851 --> 00:09:49,331 more rigid with less material. 181 00:09:49,355 --> 00:09:51,967 [Narrator] Constructing it is the next challenge 182 00:09:51,991 --> 00:09:53,869 because this is one of the first times 183 00:09:53,893 --> 00:09:58,440 a diagrid structure has been used to build a skyscraper. 184 00:09:58,464 --> 00:10:01,710 [Rob Harrison] Everybody here really felt this is 185 00:10:01,734 --> 00:10:03,946 the proper start to the project. 186 00:10:03,970 --> 00:10:07,115 Everybody around the city, anybody who was coming past 187 00:10:07,139 --> 00:10:11,353 was going to view this building rising from the ground. 188 00:10:11,377 --> 00:10:14,990 [Narrator] The plan is to start with the core of the building, 189 00:10:15,014 --> 00:10:17,492 which will act like the spine. 190 00:10:17,516 --> 00:10:21,029 The steel diagrid structure will be built around it 191 00:10:21,053 --> 00:10:23,865 and connected back to the core through a series of nodes 192 00:10:23,889 --> 00:10:27,369 in the steel frame, like the spokes on a bicycle. 193 00:10:27,393 --> 00:10:31,330 All watched carefully by the building's detractors. 194 00:10:33,532 --> 00:10:37,679 [Paul Davies] The core itself was always six floors above 195 00:10:37,703 --> 00:10:40,248 building the outside structure. 196 00:10:40,272 --> 00:10:44,353 There were 18 of these frames per floor going around 197 00:10:44,377 --> 00:10:48,690 before the next set come on top. 198 00:10:48,714 --> 00:10:51,259 [Narrator] Then, as the building gets higher, 199 00:10:51,283 --> 00:10:54,096 something strange starts to happen 200 00:10:54,120 --> 00:10:57,432 that threatens the entire project. 201 00:10:57,456 --> 00:11:00,135 [Paul Davies] Our engineering team started noticing 202 00:11:00,159 --> 00:11:02,795 things weren't exactly where they should have been. 203 00:11:05,331 --> 00:11:09,378 [music] 204 00:11:09,402 --> 00:11:13,672 [Narrator] Next, the teams have to find out what's going on. 205 00:11:15,034 --> 00:11:17,279 [Narrator] It's 2001, and in London, England, 206 00:11:17,303 --> 00:11:21,149 work is underway to build a revolutionary new skyscraper, 207 00:11:21,173 --> 00:11:23,251 but it's hit a major problem. 208 00:11:23,275 --> 00:11:26,188 For some unknown reason, the structure is moving. 209 00:11:26,212 --> 00:11:28,357 They have to find out why. 210 00:11:28,381 --> 00:11:30,392 [Paul Davies] Our engineering team started noticing 211 00:11:30,416 --> 00:11:33,128 a constant pattern of errors. 212 00:11:33,152 --> 00:11:35,664 They did something in the afternoon, 213 00:11:35,688 --> 00:11:40,268 the following morning when they checked it again, 214 00:11:40,292 --> 00:11:44,196 things were out of where they... Out of plum. 215 00:11:44,597 --> 00:11:46,775 [Narrator] After some serious detective work, 216 00:11:46,799 --> 00:11:49,211 the team discovers the culprit. 217 00:11:49,235 --> 00:11:52,447 London's famously changeable weather. 218 00:11:52,471 --> 00:11:55,784 Steel changing its dimensions due to weather is a really 219 00:11:55,808 --> 00:11:58,553 big challenge in construction. 220 00:11:58,577 --> 00:12:00,789 [Narrator] When steel gets hot, it expands. 221 00:12:00,813 --> 00:12:02,557 In cold, it contracts. 222 00:12:02,581 --> 00:12:05,494 And that is exactly what's happening here. 223 00:12:05,518 --> 00:12:08,797 In summer, in London it can be freezing cold one day 224 00:12:08,821 --> 00:12:11,800 and then the next day you have blistering heat. 225 00:12:11,824 --> 00:12:15,670 So the challenge becomes how do you calculate for temperatures 226 00:12:15,694 --> 00:12:18,507 that you can't predict? 227 00:12:18,531 --> 00:12:20,475 [Paul] The only way we could correct it 228 00:12:20,499 --> 00:12:24,813 was getting the engineers to transfer working at night 229 00:12:24,837 --> 00:12:26,281 when it was cold. 230 00:12:26,305 --> 00:12:29,017 And by and large, not very windy. 231 00:12:29,041 --> 00:12:30,685 [Narrator] And by doing just that, 232 00:12:30,709 --> 00:12:33,054 they're able to get constant measurements 233 00:12:33,078 --> 00:12:35,247 that overcome the problem. 234 00:12:36,282 --> 00:12:38,460 But the challenges don't end there 235 00:12:38,484 --> 00:12:41,329 because the engineers need to somehow counteract the building 236 00:12:41,353 --> 00:12:44,733 moving under its own weight. 237 00:12:44,757 --> 00:12:48,603 You've got the two and a half thousand tons worth of steel, 238 00:12:48,627 --> 00:12:52,374 which gradually gets loaded. Each floor adds more weight. 239 00:12:52,398 --> 00:12:55,477 That weight obviously compresses down. 240 00:12:55,501 --> 00:12:59,314 And it's a bit like overeating. Your stomach comes out, yeah? 241 00:12:59,338 --> 00:13:02,350 And it's exactly the same with this structure. 242 00:13:02,374 --> 00:13:04,019 As the weight comes on 243 00:13:04,043 --> 00:13:06,555 the circumference of the building grew. 244 00:13:06,579 --> 00:13:11,860 And each level was designed to settle by 40mm. 245 00:13:11,884 --> 00:13:14,729 It did that to perfection. 246 00:13:14,753 --> 00:13:16,364 [Narrator] The frame is designed with an 247 00:13:16,388 --> 00:13:20,602 extra bolt on each connection, so floor by floor, 248 00:13:20,626 --> 00:13:23,138 once the building finishes settling, 249 00:13:23,162 --> 00:13:25,340 the construction crews tighten them, 250 00:13:25,364 --> 00:13:28,834 creating a completely rigid structure. 251 00:13:29,768 --> 00:13:31,546 [Corina] The engineers who designed these steel frames 252 00:13:31,570 --> 00:13:34,349 are getting so good at predicting deflection. 253 00:13:34,373 --> 00:13:35,984 They can keep tolerance to a minimum 254 00:13:36,008 --> 00:13:39,488 and so get narrower gaps in framework and the facades, 255 00:13:39,512 --> 00:13:42,057 so you end up with a slicker finish. 256 00:13:42,081 --> 00:13:45,694 [music] 257 00:13:45,718 --> 00:13:48,463 [Narrator] The next challenge is getting that perfect finish 258 00:13:48,487 --> 00:13:52,968 using almost 80,000 square feet of glass. 259 00:13:52,992 --> 00:13:56,037 To pull it off, the team turns to what is at the time, 260 00:13:56,061 --> 00:13:58,707 a revolutionary idea. 261 00:13:58,731 --> 00:14:03,211 They use cutting-edge computer technology for the design. 262 00:14:03,235 --> 00:14:08,917 The result is a pattern of 7,492 panes of glass, 263 00:14:08,941 --> 00:14:11,810 but they fit without a hitch. 264 00:14:12,211 --> 00:14:13,421 And somewhat strangely in a building 265 00:14:13,445 --> 00:14:15,624 that's all about its curves, 266 00:14:15,648 --> 00:14:20,629 7,491 of them are actually flat. 267 00:14:20,653 --> 00:14:23,765 So the very last piece of glass to go in is the lens at the top 268 00:14:23,789 --> 00:14:27,302 of the building, which was 2.4 meters in diameter, 269 00:14:27,326 --> 00:14:29,704 250 kilograms. 270 00:14:29,728 --> 00:14:32,874 And the actual capping piece of glass was lifted up 271 00:14:32,898 --> 00:14:36,511 by a tower crane with the rope access guides going around it, 272 00:14:36,535 --> 00:14:39,881 installing the pressure plates that hold it down. 273 00:14:39,905 --> 00:14:42,284 [Narrator] This building is different in so many ways 274 00:14:42,308 --> 00:14:44,786 from those that have come before it 275 00:14:44,810 --> 00:14:48,047 and most that have been built since. 276 00:14:48,714 --> 00:14:50,692 [Lord Foster] It's tighter at the base. 277 00:14:50,716 --> 00:14:56,665 It swells out in the middle and it reaches a point in the sky, 278 00:14:56,689 --> 00:15:02,170 which unusually is not devoted to mechanical equipment. 279 00:15:02,194 --> 00:15:05,040 [Narrator] Most buildings have their air-conditioning units 280 00:15:05,064 --> 00:15:07,509 on the roof. 281 00:15:07,533 --> 00:15:09,945 The reason they sit outside on a roof, 282 00:15:09,969 --> 00:15:13,081 it's so that they get free ventilation to them. 283 00:15:13,105 --> 00:15:18,653 So bringing that inside the building was a challenge. 284 00:15:18,677 --> 00:15:20,689 [Narrator] In order to pull this off, 285 00:15:20,713 --> 00:15:24,125 Lord Foster needs a system of cooling the building 286 00:15:24,149 --> 00:15:28,797 that does not completely rely on air conditioning. 287 00:15:28,821 --> 00:15:32,434 It's genius is in its simplicity. 288 00:15:32,458 --> 00:15:36,438 There's six triangular light wells on every floor. 289 00:15:36,462 --> 00:15:39,107 There's four windows at the end of that light well. 290 00:15:39,131 --> 00:15:40,542 They're triangular windows. 291 00:15:40,566 --> 00:15:45,780 And they open up when the weather conditions are right. 292 00:15:45,804 --> 00:15:47,816 [Narrator] If the building is getting too hot, 293 00:15:47,840 --> 00:15:51,886 the automated glass hatches open up. 294 00:15:51,910 --> 00:15:55,090 And if it's cold outside, the windows close 295 00:15:55,114 --> 00:15:57,158 to retain the heat. 296 00:15:57,182 --> 00:16:00,862 The pinecone, which opens and closes 297 00:16:00,886 --> 00:16:03,732 according to the weather, 298 00:16:03,756 --> 00:16:06,768 it's pulling air through the lungs of the building. 299 00:16:06,792 --> 00:16:09,371 It's making it more healthy, fresher 300 00:16:09,395 --> 00:16:12,574 and dramatically reducing the amount of energy. 301 00:16:12,598 --> 00:16:17,178 Up to 50% less energy compared 302 00:16:17,202 --> 00:16:21,182 with a convential building. 303 00:16:21,206 --> 00:16:26,287 [Narrator] In December 2003, the Gherkin is finally complete. 304 00:16:26,311 --> 00:16:28,657 Stunning on the outside 305 00:16:28,681 --> 00:16:32,127 and inside, thanks to reducing the need for air conditioning, 306 00:16:32,151 --> 00:16:36,464 there's a restaurant rather than a plant room at the top. 307 00:16:36,488 --> 00:16:39,134 [Lord Foster] In that sense it's almost unique 308 00:16:39,158 --> 00:16:43,038 because the top of the building is about the panaroma 309 00:16:43,062 --> 00:16:44,939 of the city, the region. 310 00:16:44,963 --> 00:16:47,909 It's for the people. It's not for the machinery. 311 00:16:47,933 --> 00:16:50,478 [Ellie] That continuous, glazed domed roof 312 00:16:50,502 --> 00:16:52,514 with those 360 views, 313 00:16:52,538 --> 00:16:55,550 it is an exquisite design vision 314 00:16:55,574 --> 00:16:59,154 only made possible by brilliant engineers. 315 00:16:59,178 --> 00:17:02,724 [Paul] My personal feelings when we actually completed 316 00:17:02,748 --> 00:17:05,627 was one of elation, pride. 317 00:17:05,651 --> 00:17:07,862 It was the best four years of my life. 318 00:17:07,886 --> 00:17:13,668 It's given an awful lot back to the city of London. 319 00:17:13,692 --> 00:17:15,603 [Rob] Anybody who was involved in this building has 320 00:17:15,627 --> 00:17:18,606 a huge amount of pride in it. 321 00:17:18,630 --> 00:17:21,109 And its legacy will withstand 322 00:17:21,133 --> 00:17:26,648 and will retain for many, many decades to come. 323 00:17:26,672 --> 00:17:28,783 [Narrator] Born out of an atrocity, 324 00:17:28,807 --> 00:17:31,286 and vilified before it was built, 325 00:17:31,310 --> 00:17:36,558 30 St. Mary Axe has become a symbol of a new city of London. 326 00:17:36,582 --> 00:17:40,962 A building that is as clever as it is beautiful. 327 00:17:40,986 --> 00:17:44,999 A structure that challenged traditional thinking. 328 00:17:45,023 --> 00:17:47,102 And one that has changed the skyline 329 00:17:47,126 --> 00:17:49,928 for a very long time to come. 330 00:17:51,263 --> 00:17:55,067 [music] 331 00:18:00,906 --> 00:18:03,418 If I said I was gonna build a road bridge across a lake 332 00:18:03,442 --> 00:18:04,786 a mile and a half wide, 333 00:18:04,810 --> 00:18:07,255 but instead of securing the bridge to the riverbed 334 00:18:07,279 --> 00:18:09,023 and supporting it with huge towers, 335 00:18:09,047 --> 00:18:10,992 it would just float on the lake's surface 336 00:18:11,016 --> 00:18:13,061 on 77 concrete pads. 337 00:18:13,085 --> 00:18:15,797 You'd probably think that was a crazy idea. 338 00:18:15,821 --> 00:18:17,799 The thing is, in Seattle, 339 00:18:17,823 --> 00:18:21,193 one thing they really love is crazy ideas. 340 00:18:23,228 --> 00:18:27,175 [Narrator] And on the surface, that's exactly how it sounds. 341 00:18:27,199 --> 00:18:30,478 The problem was that Seattle desperately needed a new bridge 342 00:18:30,502 --> 00:18:33,448 to get people in and out of the city. 343 00:18:33,472 --> 00:18:37,552 But Lake Washington is so deep and the lake bed so soft, 344 00:18:37,576 --> 00:18:41,013 that traditional bridge building is a no-no. 345 00:18:42,314 --> 00:18:44,559 So they decided to construct the world's longest 346 00:18:44,583 --> 00:18:47,162 and widest floating bridge. 347 00:18:47,186 --> 00:18:49,497 It had to hold up a rigid road, 348 00:18:49,521 --> 00:18:52,167 yet somehow move with the natural forces 349 00:18:52,191 --> 00:18:53,892 of the water below. 350 00:18:55,761 --> 00:18:57,539 Building it pushed engineers 351 00:18:57,563 --> 00:19:01,109 into some seriously choppy waters. 352 00:19:01,133 --> 00:19:03,545 These are the kinds of problems that keep bridge engineers 353 00:19:03,569 --> 00:19:05,880 up at night. 354 00:19:05,904 --> 00:19:08,883 [Narrator] They had to create a mega drydock from scratch 355 00:19:08,907 --> 00:19:11,352 where they could construct the 77 enormous 356 00:19:11,376 --> 00:19:13,988 concrete floating pontoons. 357 00:19:14,012 --> 00:19:16,991 Any imperfection could lead to the pontoon sinking 358 00:19:17,015 --> 00:19:19,761 to the bottom of Lake Washington. 359 00:19:19,785 --> 00:19:23,531 [Narrator] Every piece had to be transported over 200 miles 360 00:19:23,555 --> 00:19:26,491 through the Pacific Ocean. 361 00:19:27,192 --> 00:19:30,872 This is the Evergreen Point Floating Bridge, 362 00:19:30,896 --> 00:19:35,100 a record breaker that took world class engineering to realize. 363 00:19:35,567 --> 00:19:38,503 So, how did they build it? 364 00:19:41,302 --> 00:19:44,748 [Narrator] It's 1997, and in the pacific northwest, 365 00:19:44,772 --> 00:19:48,618 the city of Seattle is growing bigger by the day. 366 00:19:48,642 --> 00:19:51,755 A tech boom is attracting more and more people 367 00:19:51,779 --> 00:19:56,860 making it one of the fastest growing cities in the US. 368 00:19:56,884 --> 00:20:00,497 But its infrastructure is starting to creak. 369 00:20:00,521 --> 00:20:01,865 And in particular, 370 00:20:01,889 --> 00:20:04,668 an old bridge over Lake Washington, 371 00:20:04,692 --> 00:20:07,504 a vital link to the city built in the 60's, 372 00:20:07,528 --> 00:20:10,974 which can't cope with the volume of traffic. 373 00:20:10,998 --> 00:20:13,510 There are regular backups for miles 374 00:20:13,534 --> 00:20:17,238 and it's literally cracking under the weight. 375 00:20:18,139 --> 00:20:20,650 With the existing bridge at the end of its life, 376 00:20:20,674 --> 00:20:24,145 the designers find themselves in a race to replace it. 377 00:20:25,579 --> 00:20:29,326 The weather, the traffic, the levels of the lake changing. 378 00:20:29,350 --> 00:20:31,495 These are the kinds of problems that keep bridge engineers 379 00:20:31,519 --> 00:20:33,697 awake at night. 380 00:20:33,721 --> 00:20:35,766 [Narrator] Building this bridge over Lake Washington 381 00:20:35,790 --> 00:20:38,902 poses a unique set of challenges. 382 00:20:38,926 --> 00:20:42,639 Not only will it have to span over 1.4 miles, 383 00:20:42,663 --> 00:20:46,643 but solid ground is hundreds of feet below the surface. 384 00:20:46,667 --> 00:20:49,346 Don Oats is one of the design managers 385 00:20:49,370 --> 00:20:53,583 tasked with coming up with solutions. 386 00:20:53,607 --> 00:20:55,085 [Don] Lake Washington is a unique lake. 387 00:20:55,109 --> 00:20:57,687 It's very deep. It's about 200 feet to the mud line, 388 00:20:57,711 --> 00:21:00,223 because of the volcanic eruptions it's actually filled 389 00:21:00,247 --> 00:21:04,027 with very, very soft soil to a depth of about 80 feet. 390 00:21:04,051 --> 00:21:06,630 And then below that, you'd have to excavate down 391 00:21:06,654 --> 00:21:09,332 about another 100 feet to be able to get to dirt 392 00:21:09,356 --> 00:21:13,103 that you could actually build a structural foundation on. 393 00:21:13,127 --> 00:21:15,605 [Nehemiah] If you went with the traditional suspension bridge 394 00:21:15,629 --> 00:21:17,974 like, say, the Golden Gate Bridge, 395 00:21:17,998 --> 00:21:21,812 you would end up with towers that are about 400 feet tall 396 00:21:21,836 --> 00:21:24,748 before they even got out of the water. 397 00:21:24,772 --> 00:21:26,716 [Corina] Then add another 600 to support 398 00:21:26,740 --> 00:21:28,351 the suspension bridge roadway, 399 00:21:28,375 --> 00:21:30,987 that's a 1,000-foot tall tower. 400 00:21:31,011 --> 00:21:32,480 Not gonna happen. 401 00:21:34,715 --> 00:21:38,128 [Narrator] The team takes inspiration from the old bridge 402 00:21:38,152 --> 00:21:43,057 and decides to create a new supersized floating bridge. 403 00:21:45,259 --> 00:21:48,605 This new bridge will have an extra four lanes 404 00:21:48,629 --> 00:21:51,341 and room to expand to take a light railway 405 00:21:51,365 --> 00:21:54,001 if it needs it in the future. 406 00:21:57,838 --> 00:22:00,717 The road will be elevated above the pontoons 407 00:22:00,741 --> 00:22:03,620 and cushioned with shock absorbers to stop the vibrations 408 00:22:03,644 --> 00:22:07,314 from cracking the structure. 409 00:22:07,781 --> 00:22:09,259 And everything will be balanced on top 410 00:22:09,283 --> 00:22:15,265 of 77 floating concrete pontoons anchored to the lake bed below. 411 00:22:15,289 --> 00:22:16,967 Now the engineers just need 412 00:22:16,991 --> 00:22:21,629 to float hundreds of thousands of tons of concrete. 413 00:22:22,863 --> 00:22:25,375 Making something that floats out of concrete 414 00:22:25,399 --> 00:22:27,544 may seem quite unlikely, 415 00:22:27,568 --> 00:22:30,413 but actually it's just simple physics. 416 00:22:30,437 --> 00:22:32,239 Imagine this is concrete. 417 00:22:33,274 --> 00:22:35,218 Guess what? It sinks. 418 00:22:35,242 --> 00:22:37,787 But if I take the same amount of concrete 419 00:22:37,811 --> 00:22:40,624 and shape it into a cup. 420 00:22:40,648 --> 00:22:44,018 This time, it floats. 421 00:22:46,287 --> 00:22:48,331 [Narrator] Even though making the enormous concrete 422 00:22:48,355 --> 00:22:50,800 bridge float is possible, 423 00:22:50,824 --> 00:22:53,169 constructing the giant pontoons creates its 424 00:22:53,193 --> 00:22:55,272 own set of challenges. 425 00:22:55,296 --> 00:22:59,676 Firstly, they need a massive dry dock in order to build them. 426 00:22:59,700 --> 00:23:01,645 A dry dock helps you build a boat 427 00:23:01,669 --> 00:23:03,547 or in this case, our pontoon 428 00:23:03,571 --> 00:23:07,851 in what is essentially a giant empty bathtub. 429 00:23:07,875 --> 00:23:09,953 When the pontoon is ready to float, 430 00:23:09,977 --> 00:23:13,757 the dry dock is flooded by lowering a massive gate 431 00:23:13,781 --> 00:23:16,092 and the pontoon can float out. 432 00:23:16,116 --> 00:23:17,827 [Don] We figured out it needed a basin about 433 00:23:17,851 --> 00:23:20,997 900 feet long by 200 feet wide. 434 00:23:21,021 --> 00:23:22,799 [Narrator] It's a huge area, 435 00:23:22,823 --> 00:23:26,236 roughly the size of six soccer fields. 436 00:23:26,260 --> 00:23:30,941 Which is not exactly easy to come by in a busy bustling city. 437 00:23:30,965 --> 00:23:33,376 In the end, the team finds a disused lumber yard 438 00:23:33,400 --> 00:23:37,314 80 miles away in the coastal town of Aberdeen. 439 00:23:37,338 --> 00:23:38,882 Not exactly local, 440 00:23:38,906 --> 00:23:40,984 it proves to be one of the few places available 441 00:23:41,008 --> 00:23:44,345 to build the enormous dry dock. 442 00:23:44,912 --> 00:23:46,990 Overseeing construction of the pontoons 443 00:23:47,014 --> 00:23:52,753 and the brand new $367 million dry dock is Phil Wallace. 444 00:23:53,921 --> 00:23:56,900 This is our 55-acre casting basin that we had 445 00:23:56,924 --> 00:23:59,803 down in Aberdeen, Washington. 446 00:23:59,827 --> 00:24:04,674 This basin was built, so we could cast six pontoons. 447 00:24:04,698 --> 00:24:06,209 So four along two pontoons 448 00:24:06,233 --> 00:24:08,278 and two of the auxiliaries in the back. 449 00:24:08,302 --> 00:24:11,281 We put in a gate in this area here to allow the pontoons 450 00:24:11,305 --> 00:24:12,816 to float out. 451 00:24:12,840 --> 00:24:15,685 We had over 600 employees working there 452 00:24:15,709 --> 00:24:18,755 at different times a day, working days and nights. 453 00:24:18,779 --> 00:24:20,323 [Narrator] With the dry dock ready, 454 00:24:20,347 --> 00:24:22,859 work starts on building the pontoons, 455 00:24:22,883 --> 00:24:25,629 which will be cast using over half a billion pounds 456 00:24:25,653 --> 00:24:27,631 of concrete. 457 00:24:27,655 --> 00:24:29,666 To make the pontoons, the engineers built a 458 00:24:29,690 --> 00:24:32,736 massive mold known as formwork. 459 00:24:32,760 --> 00:24:36,706 Then they started pumping in concrete to fill it. 460 00:24:36,730 --> 00:24:39,809 This is a critical stage on any build. 461 00:24:39,833 --> 00:24:42,779 [Ellie] Any imperfection could lead to a fault, 462 00:24:42,803 --> 00:24:44,247 then a fracture. 463 00:24:44,271 --> 00:24:45,615 And then ultimately, 464 00:24:45,639 --> 00:24:49,185 to the pontoon sinking to the bottom of Lake Washington. 465 00:24:49,209 --> 00:24:53,823 They're like 200 tons a piece. Everything is big. 466 00:24:53,847 --> 00:24:57,694 The most critical pour that goes in is the wall form pour, 467 00:24:57,718 --> 00:25:00,397 the exterior wall of the pontoon. 468 00:25:00,421 --> 00:25:01,898 In that pour, 469 00:25:01,922 --> 00:25:05,835 you need to make sure you have a good joint at the bottom. 470 00:25:05,859 --> 00:25:06,970 [Narrator] Although the team strives 471 00:25:06,994 --> 00:25:09,506 to make each pontoon perfect, 472 00:25:09,530 --> 00:25:14,010 they're designed with the worst-case scenario in mind. 473 00:25:14,034 --> 00:25:16,780 Instead of being a single large space, 474 00:25:16,804 --> 00:25:19,516 they're divided into sealed compartments, 475 00:25:19,540 --> 00:25:21,284 so if one leaks, 476 00:25:21,308 --> 00:25:25,088 the others can still do their job. 477 00:25:25,112 --> 00:25:29,392 So we're currently inside one of the larger pontoon cells, 478 00:25:29,416 --> 00:25:33,063 and you see hatches to the adjacent cells. 479 00:25:33,087 --> 00:25:35,999 All of these hatches are watertight. 480 00:25:36,023 --> 00:25:40,437 So keeps the cells separated in case there's any water 481 00:25:40,461 --> 00:25:42,405 entering any of these cells. 482 00:25:42,429 --> 00:25:45,809 So all of that is connected to the pontoon-monitoring system. 483 00:25:45,833 --> 00:25:47,210 So there's alarms trigger 484 00:25:47,234 --> 00:25:50,738 in case any of these cells need to be pumped out. 485 00:25:52,339 --> 00:25:55,151 [Narrator] It takes months, but eventually, 486 00:25:55,175 --> 00:26:00,323 the pontoons are completed and moored at a nearby harbor. 487 00:26:00,347 --> 00:26:03,126 But before they can be transported to Seattle, 488 00:26:03,150 --> 00:26:05,795 the engineers need to create a system for anchoring them 489 00:26:05,819 --> 00:26:08,498 in place once they get them there. 490 00:26:08,522 --> 00:26:10,934 One that can cope with the varied lake bed 491 00:26:10,958 --> 00:26:15,004 and the forces of the water. 492 00:26:15,028 --> 00:26:16,272 [Don] There were three different types of anchors 493 00:26:16,296 --> 00:26:18,942 for the different soil conditions that we had. 494 00:26:18,966 --> 00:26:21,644 The shaft anchor, eight-foot diameter steel shafts 495 00:26:21,668 --> 00:26:25,315 that go into the ground filled with concrete and a steel cage. 496 00:26:25,339 --> 00:26:29,486 [Narrator] The next anchor type is nicknamed the box of rocks. 497 00:26:29,510 --> 00:26:32,422 That are literally 40 by 40 by 20 foot tall. 498 00:26:32,446 --> 00:26:35,325 They look a lot like pontoons, but they're open top. 499 00:26:35,349 --> 00:26:38,919 They are 600 tons with all the rock in them. 500 00:26:39,286 --> 00:26:41,097 [Narrator] The last are like a supersized, 501 00:26:41,121 --> 00:26:43,800 traditional ship's anchor. 502 00:26:43,824 --> 00:26:47,871 45 will be used on the bridge. 503 00:26:47,895 --> 00:26:49,939 [Don] All the anchors we had to test for loads 504 00:26:49,963 --> 00:26:52,509 up to about 570 tons. 505 00:26:52,533 --> 00:26:56,436 So it's a massive load that these anchors can take. 506 00:26:56,703 --> 00:26:58,481 [Narrator] The pontoons are cast. 507 00:26:58,505 --> 00:27:01,050 The anchors are set. 508 00:27:01,074 --> 00:27:04,387 It's now time to tow them the 260 nautical miles 509 00:27:04,411 --> 00:27:09,683 around the coast and into Lake Washington. 510 00:27:10,150 --> 00:27:13,296 But this means going out into the open sea. 511 00:27:13,320 --> 00:27:17,767 Here the 360 by 75 foot pontoons will be at the mercy 512 00:27:17,791 --> 00:27:20,360 of the Pacific Ocean. 513 00:27:24,334 --> 00:27:25,945 [Narrator] In the pacific northwest, 514 00:27:25,969 --> 00:27:28,715 engineers are planning to transport massive cement 515 00:27:28,739 --> 00:27:31,117 pontoons through open ocean 516 00:27:31,141 --> 00:27:35,588 to construct the world's longest floating bridge in Seattle. 517 00:27:35,612 --> 00:27:38,691 You got big tractor tugs that take them up the coast. 518 00:27:38,715 --> 00:27:40,893 We didn't float them until we knew we had a nice window 519 00:27:40,917 --> 00:27:42,762 where we weren't going to have any storm conditions. 520 00:27:42,786 --> 00:27:45,331 We generally could go four knots. 521 00:27:45,355 --> 00:27:49,102 That was probably the maximum speed those pontoons could take. 522 00:27:49,126 --> 00:27:53,639 So you're out there, you know, a couple of days in the ocean. 523 00:27:53,663 --> 00:27:57,143 [Narrator] Moving each pontoon takes around two days, 524 00:27:57,167 --> 00:28:01,080 but finally the 77 are in place. 525 00:28:01,104 --> 00:28:04,517 Now the engineers face their next challenge. 526 00:28:04,541 --> 00:28:06,586 Although the pontoons are anchored, 527 00:28:06,610 --> 00:28:09,522 they move with the water of the lake. 528 00:28:09,546 --> 00:28:10,857 Somehow, they have to figure out 529 00:28:10,881 --> 00:28:13,626 how to fix this constantly moving bridge 530 00:28:13,650 --> 00:28:18,164 to the rest of the highway, which is fixed on land. 531 00:28:18,188 --> 00:28:21,300 [Nehemiah] Fixing the stationary structure to a moving one 532 00:28:21,324 --> 00:28:23,102 is incredibly difficult. 533 00:28:23,126 --> 00:28:26,706 In this case, that structure is floating on a lake. 534 00:28:26,730 --> 00:28:30,810 All kinds of things can happen to make that structure move. 535 00:28:30,834 --> 00:28:32,645 [Don] The transition span was one of the more complicated 536 00:28:32,669 --> 00:28:34,714 pieces of infrastructure we had to build. 537 00:28:34,738 --> 00:28:36,482 The floating infrastructure moves, 538 00:28:36,506 --> 00:28:38,651 fixed structure hopefully, does not. 539 00:28:38,675 --> 00:28:41,654 And so you have to figure out how to connect that. 540 00:28:41,678 --> 00:28:43,923 [Narrator] They turn to automotive engineering 541 00:28:43,947 --> 00:28:46,058 for a solution. 542 00:28:46,082 --> 00:28:49,662 We put it on what we called a large trailer hitch. 543 00:28:49,686 --> 00:28:52,131 Just like a tow hitch, this has spherical bearings 544 00:28:52,155 --> 00:28:55,067 that let the floating section of the bridge move up and down 545 00:28:55,091 --> 00:28:56,836 and side to side. 546 00:28:56,860 --> 00:29:00,773 It's these that keep the bridge from tearing itself apart. 547 00:29:00,797 --> 00:29:02,241 [Narrator] With each pontoon connected 548 00:29:02,265 --> 00:29:05,178 by massive bolts and cables. 549 00:29:05,202 --> 00:29:08,972 A raised roadway is added to the top of the pontoons. 550 00:29:10,273 --> 00:29:11,918 To prevent it from cracking, 551 00:29:11,942 --> 00:29:16,889 the entire six lane wide road sits on special shock absorbers. 552 00:29:16,913 --> 00:29:20,593 So we're currently standing on one of the longer, 553 00:29:20,617 --> 00:29:22,295 longer channel pontoon. 554 00:29:22,319 --> 00:29:26,199 This is 360 feet, so about the length of a football field. 555 00:29:26,223 --> 00:29:30,002 This makes a majority of the foundation that's 556 00:29:30,026 --> 00:29:32,805 holding up the bridge structure above us. 557 00:29:32,829 --> 00:29:34,841 You can see on all the columns here, 558 00:29:34,865 --> 00:29:37,176 there is a bearing sitting on them, 559 00:29:37,200 --> 00:29:40,146 so it allows for a little bit of movement there in the road sway. 560 00:29:40,170 --> 00:29:45,318 Those are pretty much cushions that the roadway is sitting on. 561 00:29:45,342 --> 00:29:48,321 And so along the entire bridge, you can see there's 562 00:29:48,345 --> 00:29:52,225 hundreds of these holding up the bridge stacked 563 00:29:52,249 --> 00:29:55,886 on top of all the columns. 564 00:29:56,853 --> 00:29:59,031 [Narrator] Finally, after four years, 565 00:29:59,055 --> 00:30:02,535 this 1.4 mile long record-breaking floating bridge 566 00:30:02,559 --> 00:30:04,537 is in place. 567 00:30:04,561 --> 00:30:06,305 And the first people who get to use it, 568 00:30:06,329 --> 00:30:08,674 are the families of the dedicated men and women 569 00:30:08,698 --> 00:30:10,166 who helped build it. 570 00:30:11,902 --> 00:30:14,347 We actually had a family day where all the workers 571 00:30:14,371 --> 00:30:18,150 that had worked on the job were invited out to walk the bridge. 572 00:30:18,174 --> 00:30:19,585 So the people that built the bridge, 573 00:30:19,609 --> 00:30:21,454 actually get to see it first. 574 00:30:21,478 --> 00:30:24,690 And then a couple of days later the state had a big celebration 575 00:30:24,714 --> 00:30:29,719 and over 50,000 people showed up for that celebration. 576 00:30:31,555 --> 00:30:33,032 [Don] I mean, there were some hard times 577 00:30:33,056 --> 00:30:34,800 and we went through some really stressful events. 578 00:30:34,824 --> 00:30:36,736 And some ones that you kind of laugh at now 579 00:30:36,760 --> 00:30:38,337 when you kind of think back at them, 580 00:30:38,361 --> 00:30:41,641 but there's a lot of pride that we have from it. 581 00:30:41,665 --> 00:30:43,643 [Narrator] This simple ribbon of road 582 00:30:43,667 --> 00:30:47,880 hides its importance as a marvel of innovation and engineering. 583 00:30:47,904 --> 00:30:50,483 While for locals, it's a lifesaver, 584 00:30:50,507 --> 00:30:52,618 giving them back all those hours 585 00:30:52,642 --> 00:30:54,554 that would otherwise have been spent 586 00:30:54,578 --> 00:30:57,280 sitting in a traffic jam. 587 00:30:59,516 --> 00:31:04,020 [music] 588 00:31:09,426 --> 00:31:11,103 As in all fields of creativity, 589 00:31:11,127 --> 00:31:15,041 it's easy to think that surely by now everything possible 590 00:31:15,065 --> 00:31:16,676 in architecture has been done. 591 00:31:16,700 --> 00:31:20,880 I mean, there can't be any more genuinely original ideas, right? 592 00:31:20,904 --> 00:31:23,416 But back in 2001, a call went out 593 00:31:23,440 --> 00:31:26,419 to design a new museum of science and anthropology 594 00:31:26,443 --> 00:31:28,487 for the French city of Lyon. 595 00:31:28,511 --> 00:31:29,855 The opinion-splitting building 596 00:31:29,879 --> 00:31:32,458 which resulted was totally unlike anything 597 00:31:32,482 --> 00:31:33,826 that had gone before. 598 00:31:33,850 --> 00:31:37,029 Nor has there been anything else like it ever since. 599 00:31:37,053 --> 00:31:41,467 Mold-breaking design classic or just architectural chaos? 600 00:31:41,491 --> 00:31:43,326 You decide. 601 00:31:45,795 --> 00:31:48,407 [Narrator] Take one tiny spit of reclaimed land 602 00:31:48,431 --> 00:31:51,577 sitting where two rivers join. 603 00:31:51,601 --> 00:31:53,646 We said we should move it. 604 00:31:53,670 --> 00:31:56,949 The government said, no, no way. 605 00:31:56,973 --> 00:31:59,218 [Narrator] A French city that wanted to create a building 606 00:31:59,242 --> 00:32:01,821 for which it would be remembered. 607 00:32:01,845 --> 00:32:03,789 [Corina] A building that's a cloud 608 00:32:03,813 --> 00:32:06,192 with a whirlpool in its ceiling? 609 00:32:06,216 --> 00:32:09,462 Only in France. 610 00:32:09,486 --> 00:32:12,999 [Narrator] And an architect with a passion for the extraordinary, 611 00:32:13,023 --> 00:32:15,935 and a hatred of the ordinary. 612 00:32:15,959 --> 00:32:20,573 I basically, I hate columns. 613 00:32:20,597 --> 00:32:23,943 [Narrator] And what they got was a building so complex 614 00:32:23,967 --> 00:32:28,814 that even its designers couldn't predict the final result. 615 00:32:28,838 --> 00:32:32,451 And where, from the metallic cloud-like front 616 00:32:32,475 --> 00:32:34,320 to its crystalline back, 617 00:32:34,344 --> 00:32:38,991 every piece seemed more complicated than the last. 618 00:32:39,015 --> 00:32:43,720 [Marcus] Even for us architects is how will it really look like? 619 00:32:44,020 --> 00:32:46,032 [Narrator] Nicknamed the cloud, 620 00:32:46,056 --> 00:32:49,068 This is the Musée des Confluences, 621 00:32:49,092 --> 00:32:52,805 a gravity-defying, mercurial structure, 622 00:32:52,829 --> 00:32:55,508 which would push both architects and engineers 623 00:32:55,532 --> 00:32:58,411 to realize the impossible. 624 00:32:58,435 --> 00:33:01,037 So how did they build it? 625 00:33:02,939 --> 00:33:06,519 In 2001, the rather traditional city of Lyon 626 00:33:06,543 --> 00:33:09,789 decides that it's going to bring new life to a small, 627 00:33:09,813 --> 00:33:12,858 neglected part of the city. 628 00:33:12,882 --> 00:33:14,627 A thin spit of land 629 00:33:14,651 --> 00:33:16,962 that was created over 100 years ago 630 00:33:16,986 --> 00:33:20,700 and sits where the Saone and the Rhone rivers meet. 631 00:33:20,724 --> 00:33:22,234 Until now, 632 00:33:22,258 --> 00:33:24,904 it's been little more than a local picnic spot, 633 00:33:24,928 --> 00:33:29,041 but the city has bigger plans. 634 00:33:29,065 --> 00:33:31,477 They want a centerpiece to attract new investment 635 00:33:31,501 --> 00:33:35,214 to the city on both sides of the river. 636 00:33:35,238 --> 00:33:37,316 And decide on a new museum building 637 00:33:37,340 --> 00:33:40,386 to symbolise the coming together of the two rivers 638 00:33:40,410 --> 00:33:42,655 with a meeting of minds. 639 00:33:42,679 --> 00:33:46,425 Now all they need is a design. 640 00:33:46,449 --> 00:33:50,229 They turn to award-winning architect, Wolf Prix. 641 00:33:50,253 --> 00:33:52,364 Whose buildings are as extraordinary 642 00:33:52,388 --> 00:33:54,400 as they are beautiful. 643 00:33:54,424 --> 00:33:58,795 The Musée de Confluences is going to be no exception. 644 00:33:58,995 --> 00:34:00,740 We can build everything 645 00:34:00,764 --> 00:34:06,603 and not in the stupid way of doing boxes. 646 00:34:07,036 --> 00:34:10,015 We try to liberate space. 647 00:34:10,039 --> 00:34:12,284 It is not a museum. 648 00:34:12,308 --> 00:34:17,447 It's a cloud where knowledge is traded. 649 00:34:18,414 --> 00:34:21,994 [Narrator] The city only puts one constraint on the design. 650 00:34:22,018 --> 00:34:26,065 It mustn't block public access to the end of point. 651 00:34:26,089 --> 00:34:27,600 The land is so narrow, 652 00:34:27,624 --> 00:34:30,569 this could seriously restrict what they can build. 653 00:34:30,593 --> 00:34:34,097 But Wolf has an idea. 654 00:34:34,464 --> 00:34:37,042 [Wolf] The concept of the building was 655 00:34:37,066 --> 00:34:41,313 not only to organize the exhibition spaces, 656 00:34:41,337 --> 00:34:45,084 but to lift up the building so that people can walk 657 00:34:45,108 --> 00:34:50,189 to the point of confluence and the park here. 658 00:34:50,213 --> 00:34:53,325 [Narrator] The final design is a gravity-defying building 659 00:34:53,349 --> 00:34:57,129 that lays down the gauntlet to the engineers. 660 00:34:57,153 --> 00:34:59,198 How can we build it? 661 00:34:59,222 --> 00:35:03,068 Because it was like a flying building. 662 00:35:03,092 --> 00:35:06,906 You have no idea how you can work with the architect 663 00:35:06,930 --> 00:35:10,309 just to understand what is what is willing? 664 00:35:10,333 --> 00:35:14,971 What is the objective of the architect? 665 00:35:16,072 --> 00:35:17,316 [Narrator] It's clearly going to be 666 00:35:17,340 --> 00:35:19,885 an enormous challenge for the team. 667 00:35:19,909 --> 00:35:22,688 First, they will need to build a solid base 668 00:35:22,712 --> 00:35:26,792 that's strong enough to support the weight of the building, 669 00:35:26,816 --> 00:35:28,460 while holding up the huge columns 670 00:35:28,484 --> 00:35:31,997 that will make it appear to float. 671 00:35:32,021 --> 00:35:34,834 Next, they will have to construct a steel frame, 672 00:35:34,858 --> 00:35:36,502 which will rest on top 673 00:35:36,526 --> 00:35:39,071 and be covered in 64,000 square feet 674 00:35:39,095 --> 00:35:43,976 of stainless-steel sheets to create Wolf's cloud. 675 00:35:44,000 --> 00:35:46,679 Finally, they will build the crystal. 676 00:35:46,703 --> 00:35:50,216 A spectacular entrance made from flowing glass panels 677 00:35:50,240 --> 00:35:53,319 set into a thin steel frame. 678 00:35:53,343 --> 00:35:56,522 At its heart will be a whirlpool, 679 00:35:56,546 --> 00:35:58,224 108 feet high, 680 00:35:58,248 --> 00:36:00,826 and built of specially curved glass. 681 00:36:00,850 --> 00:36:04,420 It's known as the gravity well. 682 00:36:05,955 --> 00:36:08,500 In 2010, construction begins. 683 00:36:08,524 --> 00:36:11,804 And immediately the team faces a major challenge. 684 00:36:11,828 --> 00:36:14,907 They may have plans for an extraordinary modern building, 685 00:36:14,931 --> 00:36:19,402 but they're expected to build it on land that literally sucks. 686 00:36:19,769 --> 00:36:21,814 Building on reclaimed land can potentially run 687 00:36:21,838 --> 00:36:23,549 into all kinds of issues. 688 00:36:23,573 --> 00:36:25,584 That area may be more prone to flooding. 689 00:36:25,608 --> 00:36:27,653 And because that land may have once been a river, 690 00:36:27,677 --> 00:36:31,423 it might be more unstable and prone to subsidence. 691 00:36:31,447 --> 00:36:36,795 [music] 692 00:36:36,819 --> 00:36:38,130 [Narrator] Next, 693 00:36:38,154 --> 00:36:41,000 even the architect has second thoughts. 694 00:36:42,801 --> 00:36:45,747 [Narrator] In 2010, in Lyon, France, 695 00:36:45,771 --> 00:36:49,250 work is underway to build a magnificent new museum. 696 00:36:49,274 --> 00:36:52,387 The only problem is, it's on reclaimed land 697 00:36:52,411 --> 00:36:55,423 made up of loose sand. 698 00:36:55,447 --> 00:36:57,592 They said we should move it. 699 00:36:57,616 --> 00:37:00,295 The government said, no, no way. 700 00:37:00,319 --> 00:37:05,900 This is the most important point in this city. 701 00:37:05,924 --> 00:37:08,536 [Narrator] So engineers design foundations, 702 00:37:08,560 --> 00:37:12,273 which include 570 deep piles 703 00:37:12,297 --> 00:37:16,911 with a reinforced concrete slab sitting on top. 704 00:37:16,935 --> 00:37:18,446 Onto that, 705 00:37:18,470 --> 00:37:23,542 they plan to fix the columns to hold up the massive cloud. 706 00:37:24,877 --> 00:37:30,024 [Markus] We had to put a lot of piles in to reinforce the earth. 707 00:37:30,048 --> 00:37:32,861 We also lifted up, even the plinth, 708 00:37:32,885 --> 00:37:35,430 the concrete part of this building 709 00:37:35,454 --> 00:37:38,857 to be over the ground water. 710 00:37:40,459 --> 00:37:43,471 [Narrator] It takes time and an awful lot of concrete. 711 00:37:43,495 --> 00:37:46,908 But there are now solid foundations. 712 00:37:46,932 --> 00:37:49,477 The next big challenge is to work out how on earth 713 00:37:49,501 --> 00:37:54,282 they're going to build the enormous, show-stopping cloud. 714 00:37:54,306 --> 00:37:56,217 To make it appear to float, 715 00:37:56,241 --> 00:37:59,912 they take inspiration from an old-world engineering idea. 716 00:38:01,346 --> 00:38:07,228 Construction of the cloud is the construction of a bridge. 717 00:38:07,252 --> 00:38:10,165 [Ellie] A girder bridge is perhaps the most classic bridge 718 00:38:10,189 --> 00:38:12,267 design that you and I are most familiar with. 719 00:38:12,291 --> 00:38:16,838 The bridge deck is held up by huge iron or concrete girders 720 00:38:16,862 --> 00:38:21,342 that transfer the load to the supporting columns. 721 00:38:21,366 --> 00:38:24,078 [Narrator] At its heart, the complex floating structure 722 00:38:24,102 --> 00:38:28,550 is made up of a series of interconnecting steel beams. 723 00:38:28,574 --> 00:38:32,821 These allow the team to create the unique cloud-like shape. 724 00:38:32,845 --> 00:38:34,789 And just like a bridge, 725 00:38:34,813 --> 00:38:37,325 the forces from this are transferred to the ground 726 00:38:37,349 --> 00:38:39,561 through a series of columns. 727 00:38:39,585 --> 00:38:41,563 But its extraordinary irregular shape 728 00:38:41,587 --> 00:38:45,166 makes it difficult to calculate how the loads will work. 729 00:38:45,190 --> 00:38:48,870 A miscalculation could lead to the engineering failing 730 00:38:48,894 --> 00:38:51,697 and the building collapsing. 731 00:38:53,232 --> 00:38:57,078 The cloud is very hard to understand 732 00:38:57,102 --> 00:38:59,547 and to describe because it's a cloud. 733 00:38:59,571 --> 00:39:04,886 So how do you describe the shape of the cloud is not possible. 734 00:39:04,910 --> 00:39:07,655 [Narrator] Hoping to make the impossible, possible, 735 00:39:07,679 --> 00:39:09,991 the team tries to build a computer model, 736 00:39:10,015 --> 00:39:12,017 but even that's not easy. 737 00:39:13,552 --> 00:39:16,064 You let the computer working one day, 738 00:39:16,088 --> 00:39:18,900 you come back after one day, you look at it, 739 00:39:18,924 --> 00:39:20,568 and it doesn't function. 740 00:39:20,592 --> 00:39:22,470 You have to try another solution, 741 00:39:22,494 --> 00:39:24,873 but you wait always one day 742 00:39:24,897 --> 00:39:28,543 to have the response of your idea. 743 00:39:28,567 --> 00:39:32,080 [Narrator] Eventually, after some serious number crunching, 744 00:39:32,104 --> 00:39:35,383 the engineers arrive at a structure that is as stable 745 00:39:35,407 --> 00:39:38,710 as it is breathtaking. 746 00:39:39,244 --> 00:39:42,314 The construction crew gets to work building it. 747 00:39:43,048 --> 00:39:46,027 Here you have really complex connections of this different 748 00:39:46,051 --> 00:39:48,530 secondary steel structures. 749 00:39:48,554 --> 00:39:51,266 It worked well due to this really 750 00:39:51,290 --> 00:39:54,168 sophisticated 3D model. 751 00:39:54,192 --> 00:39:57,205 [Narrator] Once the main steel frame in place, 752 00:39:57,229 --> 00:40:00,008 the team then creates its irregular shape 753 00:40:00,032 --> 00:40:03,311 by constructing a smaller frame on top, 754 00:40:03,335 --> 00:40:05,847 which is clad in 64,000 square feet 755 00:40:05,871 --> 00:40:09,584 of stainless-steel paneling. 756 00:40:09,608 --> 00:40:11,286 The next challenge facing the team 757 00:40:11,310 --> 00:40:14,022 is how they're going to build the crystal, 758 00:40:14,046 --> 00:40:17,992 a massive glass atrium, which will go at the front. 759 00:40:18,016 --> 00:40:21,629 A challenge Wolf isn't making any easier. 760 00:40:21,653 --> 00:40:25,567 Basically, I hate columns. 761 00:40:25,591 --> 00:40:29,604 To solve a stupid column 762 00:40:29,628 --> 00:40:34,042 in many parts was the goal. 763 00:40:34,066 --> 00:40:36,711 [Narrator] Wolf wants to have an open space. 764 00:40:36,735 --> 00:40:41,950 But it's vast and they need to find a way to support the roof. 765 00:40:41,974 --> 00:40:46,554 Because of this interaction between all the elements, 766 00:40:46,578 --> 00:40:48,790 it was very hard to achieve 767 00:40:48,814 --> 00:40:52,517 the structural design of the crystal. 768 00:40:53,952 --> 00:40:56,998 [Narrator] The solution for how to support the roof 769 00:40:57,022 --> 00:41:02,194 lies in an extraordinary idea. 770 00:41:04,129 --> 00:41:08,676 Imagination comes from, from the turbulences 771 00:41:08,700 --> 00:41:11,446 when two rivers coming together. 772 00:41:11,470 --> 00:41:15,350 This is the experiment, we did in our office 773 00:41:15,374 --> 00:41:19,754 to see how a turbulence look like when two streams 774 00:41:19,778 --> 00:41:22,023 coming together. 775 00:41:22,047 --> 00:41:26,127 Then this is the plan. 776 00:41:26,151 --> 00:41:30,431 It's the columns not being a column. 777 00:41:30,455 --> 00:41:32,533 [Narrator] Wolf's idea is to create a support 778 00:41:32,557 --> 00:41:34,669 that doesn't look like a column. 779 00:41:34,693 --> 00:41:37,605 So they make a void in the middle of the atrium, 780 00:41:37,629 --> 00:41:41,342 almost as if a giant finger has pushed the roof down 781 00:41:41,366 --> 00:41:42,810 to touch the floor. 782 00:41:42,834 --> 00:41:46,214 Constructed from glass and steel it looks perfectly in place 783 00:41:46,238 --> 00:41:48,282 with the rest of the structure, 784 00:41:48,306 --> 00:41:52,053 but it's also supporting the entire roof. 785 00:41:52,077 --> 00:41:55,223 The extraordinary mix of sculpture and engineering 786 00:41:55,247 --> 00:41:59,293 is nicknamed the gravity well. 787 00:41:59,317 --> 00:42:01,529 If your structure contains a cone-like shape that's 788 00:42:01,553 --> 00:42:03,331 tapered to the ground, 789 00:42:03,355 --> 00:42:07,602 the forces will be transferred to the apex or tip of that cone. 790 00:42:07,626 --> 00:42:10,371 So this shape is not only interesting architecturally, 791 00:42:10,395 --> 00:42:14,575 it also serves a structural purpose. 792 00:42:14,599 --> 00:42:16,244 [Narrator] The next challenge, 793 00:42:16,268 --> 00:42:18,546 is making the structure strong enough to be able to deal 794 00:42:18,570 --> 00:42:21,049 with 15 feet of snow. 795 00:42:21,073 --> 00:42:22,417 They start with a cladding 796 00:42:22,441 --> 00:42:26,621 of specially reinforced glass panels. 797 00:42:26,645 --> 00:42:29,791 But the clever engineering doesn't stop there. 798 00:42:29,815 --> 00:42:32,260 [Marcus] We have in the lower parts, 799 00:42:32,284 --> 00:42:35,963 we have heated glass panels. 800 00:42:35,987 --> 00:42:38,766 And the drainage is also heated 801 00:42:38,790 --> 00:42:41,703 and the structure is strong enough 802 00:42:41,727 --> 00:42:44,639 to take the pressure of snow. 803 00:42:44,663 --> 00:42:50,211 [Narrator] Finally in 2014, after four years of construction 804 00:42:50,235 --> 00:42:53,347 the Musée de Confluences is complete, 805 00:42:53,371 --> 00:42:57,609 and the results are extraordinary. 806 00:42:58,243 --> 00:43:02,657 It's a very open special, 807 00:43:02,681 --> 00:43:04,892 not museum. 808 00:43:04,916 --> 00:43:09,921 It's a building for trading knowledge. 809 00:43:13,291 --> 00:43:16,104 [Marcus] I'm very, very, very proud. 810 00:43:16,128 --> 00:43:21,600 And it was really great to be part of this team. 811 00:43:23,235 --> 00:43:24,746 [Gabriel] Maybe one time in your life, 812 00:43:24,770 --> 00:43:26,514 you make this kind of project. 813 00:43:26,538 --> 00:43:28,282 So all your life, 814 00:43:28,306 --> 00:43:32,177 you will remember and you will remember this experience. 815 00:43:34,179 --> 00:43:36,924 [Narrator] This cutting-edge design transforms 816 00:43:36,948 --> 00:43:40,485 what a museum can be, 817 00:43:43,388 --> 00:43:48,160 creating an open, welcoming space that beckons people in. 818 00:43:50,162 --> 00:43:53,341 And just like the two rivers that surround it, 819 00:43:53,365 --> 00:43:57,369 it will bring people together for years to come.