0 00:00:08,378 --> 00:00:11,586 - So now, we're going to look at the second mentor 1 00:00:11,586 --> 00:00:14,867 that I mentioned, Gustav Lindenthal, and who was he 2 00:00:14,867 --> 00:00:18,746 because he also played an important role for Ammann. 3 00:00:18,746 --> 00:00:22,249 So Lindenthal came from Austria to the US 4 00:00:22,249 --> 00:00:26,196 and his mentoring, the teachings that he had with Ammann 5 00:00:26,196 --> 00:00:28,520 was more of a practical experience 6 00:00:28,520 --> 00:00:30,551 and the politics of bridge design, 7 00:00:30,551 --> 00:00:32,570 two very important aspects. 8 00:00:32,570 --> 00:00:35,876 So Ammann, actually in 1902, came to the US, 9 00:00:35,876 --> 00:00:38,373 he found the US a great opportunity to become 10 00:00:38,373 --> 00:00:40,948 a bridge designer, not unlike John Roebling, 11 00:00:40,948 --> 00:00:43,619 when we talked about the Brooklyn Bridge. 12 00:00:43,619 --> 00:00:46,245 So in 1902 Ammann came to the US, 13 00:00:46,245 --> 00:00:50,588 and in 1912, Gustav Lindenthal hired Ammann. 14 00:00:50,588 --> 00:00:53,203 And the project that Ammann worked on with Lindenthal 15 00:00:53,203 --> 00:00:56,421 would be his first real major bridge design, 16 00:00:56,421 --> 00:00:59,334 was for the Hell Gate Bridge on the East River. 17 00:00:59,334 --> 00:01:01,139 And this is the East River, the same river 18 00:01:01,139 --> 00:01:04,703 as the Brooklyn Bridge, but much further north. 19 00:01:04,703 --> 00:01:07,778 So two proposals were put forward for this bridge, 20 00:01:07,778 --> 00:01:09,996 one was a crescent arch shape, 21 00:01:09,996 --> 00:01:13,394 and the other was called a spandrel braced arch. 22 00:01:13,394 --> 00:01:16,552 So Lindenthal looked at both of these proposals 23 00:01:16,552 --> 00:01:20,625 and considered both of them, but he liked very much 24 00:01:20,625 --> 00:01:24,750 the towers, so those large towers are really what influenced 25 00:01:24,750 --> 00:01:28,333 Lindenthal to choose the spandrel braced arch, 26 00:01:28,333 --> 00:01:32,357 the design where the arch spreads and gets deeper 27 00:01:32,357 --> 00:01:34,399 when it gets to that abutment. 28 00:01:34,399 --> 00:01:37,350 Because this was Lindenthal's aesthetic, he really preferred 29 00:01:37,350 --> 00:01:41,005 the massive to the light, he liked massive structures, 30 00:01:41,005 --> 00:01:43,292 that was his aesthetic. 31 00:01:43,292 --> 00:01:46,757 So the bridge was completed in 1916 and it was a bridge 32 00:01:46,757 --> 00:01:49,144 for railroad loads, it wasn't for automobiles, 33 00:01:49,144 --> 00:01:52,176 in 1916 we're still talking about the railroad 34 00:01:52,176 --> 00:01:55,086 and this is what Lindenthal was designing, he was a famous 35 00:01:55,086 --> 00:01:58,176 bridge designer for railroad bridges. 36 00:01:58,176 --> 00:02:01,435 So the Hell Gate Bridge, aesthetically, you could look at it 37 00:02:01,435 --> 00:02:04,636 and make a judgement for yourself, the elegance of it. 38 00:02:04,636 --> 00:02:06,645 We're gonna look at it also from the efficiency 39 00:02:06,645 --> 00:02:09,331 and economy point of view, so if you look at an image 40 00:02:09,331 --> 00:02:12,474 of this bridge under construction, what you see is that 41 00:02:12,474 --> 00:02:16,592 the top cord is not connected to that abutment structure 42 00:02:16,592 --> 00:02:20,150 on the two ends, which means that all the load comes down 43 00:02:20,150 --> 00:02:22,849 just to the bottom cord, that top cord there, 44 00:02:22,849 --> 00:02:26,000 near the abutment, isn't doing any work. 45 00:02:26,000 --> 00:02:28,817 So in a way, it's a little bit of a dishonest bridge 46 00:02:28,817 --> 00:02:31,624 because when you look at it, it gives you that impression 47 00:02:31,624 --> 00:02:34,335 that the bridge truss needs to get deeper 48 00:02:34,335 --> 00:02:36,851 towards the abutment, but it actually doesn't. 49 00:02:36,851 --> 00:02:40,795 That was an aesthetic choice that Lindenthal made. 50 00:02:40,795 --> 00:02:43,196 So again, if you look at Lindenthal's aesthetic, 51 00:02:43,196 --> 00:02:46,135 he tended to separate aesthetic from structure. 52 00:02:46,135 --> 00:02:48,626 It wasn't a real honest expression 53 00:02:48,626 --> 00:02:50,344 of what the structure was doing, 54 00:02:50,344 --> 00:02:53,793 and he preferred the massive to the light as well. 55 00:02:53,793 --> 00:02:57,400 But regardless, Lindenthal is an important engineer 56 00:02:57,400 --> 00:02:59,821 that should be regarded as a great engineer, 57 00:02:59,821 --> 00:03:02,720 in particular of railroad bridges. 58 00:03:02,720 --> 00:03:05,483 We look at an image of it after it was completed, 59 00:03:05,483 --> 00:03:09,030 the construction, and in this old photograph, you can see 60 00:03:09,030 --> 00:03:12,554 Lindenthal and Ammann, so you see the relative size 61 00:03:12,554 --> 00:03:14,471 of the scale of the two men. 62 00:03:14,471 --> 00:03:16,585 David Billington would say that Lindenthal was 63 00:03:16,585 --> 00:03:20,879 a very large man, and he was symbolic of the railroad age, 64 00:03:20,879 --> 00:03:24,635 whereas Ammann was a very small-framed man, 65 00:03:24,635 --> 00:03:27,548 and symbolic of the automobile age. 66 00:03:27,548 --> 00:03:30,057 And we're gonna see that Ammann is gonna go on 67 00:03:30,057 --> 00:03:34,025 to design, really, automobile bridges, not railroad bridges. 68 00:03:34,025 --> 00:03:36,383 If we compare this old image after the completion 69 00:03:36,383 --> 00:03:40,921 of the Hell Gate Bridge in 1916 to a more modern photograph 70 00:03:40,921 --> 00:03:44,632 of the Hell Gate, you can see that the bridge remains 71 00:03:44,632 --> 00:03:48,562 exactly the same, but the context, the culture surrounding 72 00:03:48,562 --> 00:03:52,111 it has changed, very similar to that idea that I showed you 73 00:03:52,111 --> 00:03:55,566 with the Brooklyn Bridge, contrasting the two images. 74 00:03:55,566 --> 00:03:58,616 So on the right, you see the men in suits and top hats, 75 00:03:58,616 --> 00:04:01,850 and on the left, you see an image of the bridge 76 00:04:01,850 --> 00:04:04,688 as it looks like today, people are sunning in bikinis 77 00:04:04,688 --> 00:04:07,793 and the men with no shirts, again it's a different culture, 78 00:04:07,793 --> 00:04:10,161 the culture surrounding these bridges have changed 79 00:04:10,161 --> 00:04:14,340 dramatically but the bridges remain exactly the same. 80 00:04:14,340 --> 00:04:16,805 You can see this bridge, actually, if you're traveling 81 00:04:16,805 --> 00:04:19,245 from train from New York to Boston. 82 00:04:19,245 --> 00:04:22,102 You won't see it as you go under the bridge, 83 00:04:22,102 --> 00:04:24,393 because if the train is under it, 84 00:04:24,393 --> 00:04:26,997 you don't see it, it's right above you, but as the train 85 00:04:26,997 --> 00:04:30,183 actually turns a corner, if you grab your camera quickly 86 00:04:30,183 --> 00:04:33,046 you'll catch a sight of the Hell Gate Bridge 87 00:04:33,046 --> 00:04:35,501 and I had that opportunity as I was traveling 88 00:04:35,501 --> 00:04:38,299 to a conference with my colleague, Branko Glisic. 89 00:04:38,299 --> 00:04:40,547 He and I were going to a conference in Boston, 90 00:04:40,547 --> 00:04:42,795 I grabbed the camera, and there's Branko 91 00:04:42,795 --> 00:04:47,086 with the Hell Gate Bridge in the background.