After the terrorist attacks that brought down the twin towers in Manhattan, many said it was the end of an era for skyscrapers. New York City proved them wrong. The building constructed to replace the towers, 1 World Trade Center, has risen above 1,250 feet and surpassed the Empire State Building as the tallest in New York.
David Childs, the lead architect and designer of 1 World Trade Center, was involved in the construction of several megastructures around New York. "There was a real void in the sky that was formed when the buildings came down," he tells NPR's Neal Conan. "We have learned a lot from the lessons of 9/11 to make buildings better. But I think that as far as the image of the city, it's always been there. ...
"They're fascinating. And they really do make the image of a city, which we all, I think, respond well to."
From lower Manhattan to Dubai, Kuala Lumpur to Shanghai, buildings continue to reach ever higher. Originating in Chicago in the 1890s, skyscrapers push the limits of gravity and human ingenuity, and countries around the world battle for the rights to the tallest building.
Childs explains the challenges of constructing New York's tallest building, and why we're so fascinated by skyscrapers.
On why we love skyscrapers
"It's, I believe, in our DNA to want to congregate as people. People want to get together, whether it's for worship or marketplace or for business, commerce. And downtown certainly has had commerce and financial activities at its core ever since its beginning.
" ... And so you have to push buildings up to be able to get that density. As a result, it's actually one of the most efficient, environmentally sound constructions because you have so many people working and living exactly where all the infrastructure has been put."
On the design of skyscrapers
"The tall buildings really are unique ... They're not just high rises. They really are skyscrapers, and you have to design them very carefully ... The big force is wind, it's the overturning moment. If you think about a sailboat, it catches the wind and it wants — it leans over. That mast dips off of a perpendicular.
"... In a tall building, which is very slender, you can't sort of spread its legs like one human being would to withstand a horizontal force. So you have to design them, and in this case it's bolted down to actually the most wonderful base, which is that enormous great shift of granite that goes underneath all of New York. And so it's pretty firm and pretty fixed and very robust."
On constructing 1 World Trade Center
"All of the steel and the concrete that goes into it, let alone the skin and then finally the tenant and all the furniture that will be in there, it's an enormous, enormous load. There's about 80 feet between grade and the rock. And in that, interesting enough, right underneath these very tall buildings goes the PATH train, which is the train that takes commuters from New York to New Jersey. And it's not only going through, but it's curving at that point, so technically it was very difficult to do.
"But in that space, it was empty before because they had built what they called the bathtub to keep out the Hudson River. This building is in the Hudson River. It just happens to be, you know, decked over and fill put in place. But it was originally not till you got up to Greenwich Street that the lapping waves of the edge of the river occurred. So it was very, very complicated to be able to build it all, get down there, tie it to the base and then begin construction from grade up. That was relatively simple because it's quite repetitive as you go up."
NEAL CONAN, HOST:
Earlier this week, a new building took the mantle as New York's tallest, and One World Trade Center still has 500 feet to go. After 9/11, many predicted the demise of the skyscraper, but megastructures continue to rise around the world: national status symbols, testaments to human ingenuity. Was there one building, one moment that riveted your imagination?
Give us a call: 800-989-8255. Email us: email@example.com. You can also join the conversation on our website. That's at npr.org. Click on TALK OF THE NATION. David Childs is lead architect of One World Trade Center. He joins us from our bureau in New York. And congratulations.
DAVID CHILDS: Great. Thank you, Neal. Glad to be here.
CONAN: And I wonder, when you were growing up, was there one building, one moment that you said, wow?
CHILDS: Well, I suppose in my youth, I remember best that great station, Pennsylvania Station in New York, which we lost to demolition a number of years ago. But as tall buildings - no, not really. I grew up, in part, in Washington, and I always thought that the Washington Monument was pretty terrific. But, of course, it has no windows in it.
CONAN: It does not have any windows. Washington, interestingly, the city that mandates no tall structures, nothing taller than that Washington Monument.
CHILDS: Yes. In fact, when I was head of the planning commission down there, I was a greatest supporter of that, because it's ironic that Washington is a European town, but it is our nation's capital. And then the fact that it's distinguished, you know, singular like that, I think, is appropriate.
CONAN: You have designed - been involved in the construction of several megastructures. Why did you get interested in that?
CHILDS: Well, as an architect, and if you - you're either interested in smaller-scale rooms or even furnishings, or in the largest projects, airports or tall buildings. I just happened to be towards that other end, that one end that is interested in city building. And, of course, those elements are often large projects, large projects like the rebuilding of ground zero.
CONAN: And some people would call them grandiose. Do, you, too, call them that? Obviously, you probably come down more on the grand part.
(SOUNDBITE OF LAUGHTER)
CHILDS: Well, you're right there. No, I think the grand is certainly complicated. City buildings tend to be an enormous infrastructure, and all sorts of concerns about density and supplying services and so forth, but they're fascinating. And they really do make the image of a city, which we all, I think, respond well to.
CONAN: There is a special mission to One World Trade Center.
CHILDS: Yes. In the master plan, it called for that to be the tallest building down there. I chose to have the building - which is now being built and not yet topped out, but almost - to be exactly the same height as one of the towers that fell: 1,368 feet. The ceremony this week was to mark the, I guess, friendly competition between which one is the tallest, and the Empire State Building held that record until this time. But I tell you, Neal, that if you go up in the buildings and you look across the city, it's very hard to tell which one is taller at that height.
CONAN: Yet when the Trade Centers were there, it wasn't hard to tell that they were taller than the Empire State Building.
CHILDS: Well, you know, that's interesting. I think you're absolutely right, because they were a significant jump from the other buildings in the downtown, one of the great cores of our city here, the other being Midtown, where the Empire State Building is, along with Chrysler and other tall buildings. So you're right. There was a real void in the sky that was formed when the buildings came down, and that fact was mentioned to me often. So I was always a great proponent of rebuilding, and rebuilding a tall building downtown. And that's exactly what's happened now.
CONAN: That building makes a particular statement. But, in general, what statement do grand structures like One World Trade Center, the Empire State Building, the Chrysler Building or the old Sears Tower in Chicago. What do they say?
CHILDS: Well, they say something about our - it's, I believe, in our DNA to want to congregate as people. People want to get together, whether it's for worship or marketplace or for business, commerce. And downtown certainly has had commerce and financial activities at its core ever since its beginning. So that the density that you have - and New York is alone - frankly, like Hong Kong - in being a very tight island, Manhattan portion of it. And so you have to push buildings up to be able to get that density. As a result, it's actually one of the most efficient, environmentally sound constructions because you have so many people working and living exactly where all the infrastructure has been put. So I think that the, you know, cost per square foot in terms of energy and all its environmental matters is actually wonderfully low in New York City compare to suburban development.
CONAN: They also have to be visionary, yet in so many cases, certainly the case with the Empire State Building when it first opened, and now that world's tallest building in Dubai, a lot of unoccupied space.
CHILDS: Well, you do have the cyclical matters. When the Empire State Building was built, of course, it was right at the Depression. They built it in a record time. And it took a while to fill up and then fall, and then, of course, markets went down, emptier(ph) for a little while, so it's back and forth. But the signs are all good for major new infrastructure to come in, and a need for these new buildings that are technologically much better than they were even 10 years ago. And we do - we have learned a lot from the lessons of 9/11 to make buildings better. But I think that as far as the image of the city, it's always been there, the tallest buildings in the medieval or Gothic towns, of course, were the cathedral. And then there was other spires. Trinity Church right there at ground zero was the tallest building in America for a long, long time.
CONAN: Now dwarfed, of course.
CHILDS: Now absolutely dwarfed. But it's a wonderful graveyard space around. It's full of people having lunch there. And I believe that will be the case in the buildings at the memorial and the parks around it too. So it's designed for people at ground level just as much it is about what you see on the skyline.
CONAN: We're talking with David Childs, design partner at Skidmore, Owings and Merrill, chief architect and designer of One World Trade Center, which this past week rose to become the tallest building in New York City. 800-989-8255. Email us: firstname.lastname@example.org. Was there one building, one moment that riveted your imagination? We'll start with Anthony. Anthony is with us from Baton Rouge.
ANTHONY: Yes. How are you doing? First time calling, Neal. I'm a big fan of the show. And I just wanted to talk about - I'm from New Jersey originally, and I had the Empire State Building in my backyard, and of course I grew up around the World Trade Center. And I used to work right on 300 - 350 Hudson Street right when the towers came down. So that's a very personal thing for me. And then I lived in Chicago for a few years, and a building (unintelligible) me the most was the Hancock building. It really had more of effect - an effect for me, more so than the Sears Tower. I just like just that, you know, that dark building just in the middle of the town and just how, you know, how it's broad at the bottom and then gets narrow at the top. And then just about the history of, you know, of the building and how it swings.
I know this is less of a building. It's a monument, but the St. Louis Arch has always had an effect on me. Just how the, you know, the time - the short amount of time that it took for them to build it and just building it from the base and then meeting in the middle, you know? I know it's a monument, not a building but, you know, just for the engineering aspect of it, you know, what Eero Saarinen was able do with that design, you know, that's really, you know, what - how those things affected me.
CONAN: And, David Childs, I think it works primarily for that twist in the arch?
CHILDS: Well, yes, exactly. That's a beautiful symbol of the gateway that was opening from the East to the West, which, of course, is its purpose there. And it was very complicated to build that structure because, of course, it leans against each other and had to meet exactly in the middle. But it was beautifully done, and it's a real symbol all till today. Everybody knows exactly what it is.
CONAN: Anthony, thanks very much for the call, and thanks for the kind words.
ANTHONY: Thank you, Neal.
CONAN: Let's if we go next to - this is Gene. Gene with us from Fresno.
GENE: Hi, Neal. Great fan of your show. Thank God you're on the air because I wouldn't know what to listen to if you guys weren't there.
CONAN: Thank you very much. Go ahead, please.
GENE: Well, my big experience - my dad had a job putting antennas on big buildings. And I was on the World Trade Center on the very top looking straight down. And that for me was, I mean I've been on other tall buildings, and looking down, they're normally tapered. You don't get a clear shot to the ground.
But the World Trade Center, when I went to the edge, I laid down. I poked my head over to the side there. It was the first time I experienced fear. My dad had told about this. (Unintelligible) son, you better be careful with that because you're going to look over the edge one day and there's this fear that grips you that kind of immobilizes you. And I was like, what are you talking about, Pops, you know, I'm not going to worry about that. Well, sure enough, I looked over the edge. And when you look down, it looks like it's going underneath you. You could see straight down (unintelligible) describe. It's like, oh my gosh, and I was so scared for the moment, and that was pretty much, you know, my adventures of looking over the edge of a building.
(SOUNDBITE OF LAUGHTER)
GENE: After that - because I don't know what the term for that is, but it was amazing.
CONAN: I think it's called vertigo.
GENE: I think that's the word.
CONAN: Yeah. And I guess you're not going to be the next Philippe Petit.
GENE: No. No, no, no, I'm not crossing any buildings with ropes, I think is what you're referring to. But it just - when you look down, it looks like it goes under you, not exactly straight down. It's such a strange feeling. And I almost swore I could feel a little wobble. Maybe the fear was what was kicking in.
CONAN: Could have been your knees shaking, yes.
(SOUNDBITE OF LAUGHTER)
GENE: Yeah. Great(ph) fan of your show, and that was my experience with tall buildings and that was the end of it for me. And now I do paragliding, so I have something that holds me up.
(SOUNDBITE OF LAUGHTER)
CONAN: OK. Gene, thanks very much for the call.
GENE: Thank you too.
CONAN: David Childs, do you go to the edge and look over?
CHILDS: Well, I do. I'm one of those fortunate people that aren't so worried about it. But I think that Gene(ph) is just right. If you are attached to the building, you feel much more the sense of vertigo than if you were actually flying over it. Nobody has that same feeling when they're in airplanes. And buildings, of course, do wobble. They move back and forth, and we design them to be stiffer or less stiff, depending upon the occupancy. Residential buildings, you just don't want to have any movement that you can keep away. But in tall buildings, they do move back and forth in the wind. You can't resist everything. And, in fact, being supple is actually a feature of tall buildings.
CONAN: Was the greatest press agent for the skyscraper King Kong?
(SOUNDBITE OF LAUGHTER)
CHILDS: I suppose for the Empire State Building it was, although it comes back to haunt us in our thoughts about it. The tall buildings really are unique. They - they're not just high rises. They really are skyscrapers, and you have to design them very carefully to withstand - not gravity. You would think that would be the greatest force in a big, heavy building like that. But the big force is wind, it's the overturning moment. If you think about a sailboat, it catches the wind and it wants - it leans over. That mast dips off of a perpendicular.
So to be - and, of course, in a tall building, which is very slender, you can't sort of spread its legs like one human being would to withstand a horizontal force. So you have to design them, and in this case it's bolted down to actually the most wonderful base, which is that enormous great shift of granite that goes underneath all of New York. And so it's pretty firm and pretty fixed and very robust.
CONAN: We're talking with David Childs, design partner at Skidmore, Owings and Merrill, chief architect and designer of One World Trade Center. You're listening to TALK OF THE NATION from NPR news. And I've had the chance to be in downtown New York a couple of weekends over the past year, overlooking different parts of the construction site, the last one just a couple of weekends ago, overlooking the One World Trade Center and the new memorials. And as I looked at it, I was reminded of - can you give us some idea? You talked about being bolted down to that granite, but the amount - the weight of the material being excavated in relation to the weight of the building.
CHILDS: Well, actually, I don't know that. It's an interesting question. It's actually(ph) probably really quite minor when you think about a building that tall. You know, it's a very, very tall building and all of the steel and the concrete that goes into it, let alone the skin and then finally the tenant and all the furniture that will be in there, it's an enormous, enormous load. There's about 80 feet between grade and the rock. And in that, interesting enough, right underneath these very tall buildings goes the PATH train, which is the train that takes commuters from New York to New Jersey. And it's not only going through, but it's curving at that point, so technically it was very difficult to do.
But in that space it was empty before because they had built what they called the bathtub to keep out the Hudson River. This building is in the Hudson River. It just happens to be, you know, decked over and fill put in place. But it was originally not till you got up to Greenwich Street that the lapping waves of the edge of the river occurred. So it was very, very complicated to be able to build it all, get down there, tie it to the base and then begin construction from grade up. That was relatively simple because it's quite repetitive as you go up.
CONAN: Yeah. Let's go to John, John with us from Tulsa.
JOHN: Hi there. This is John in Tulsa. I wanted to tell you my - I went on a bicycle tour of England and France when I graduated college in 1985 before all the security measures. And I went up to the top of Notre Dame Cathedral, and I was able to go out and scramble up the 10 roofs up to that pole on the very top and hang on one arm and just lean out over the city. And when I think about my tour of England and France, I think that was my moment. Just seeing all the flying buttresses and all the architecture just was amazing. And just standing above the city on the top of Notre Dame was amazing. That was my - that was my moment.
CONAN: Anyone who does not have vertigo will envy you.
(SOUNDBITE OF LAUGHTER)
CONAN: Thanks, John, very much. And he mentioned the flying buttresses and those - the other architectural elements of the Gothic cathedral. We have come such a long way. Materials have made such a huge difference in how we construct our buildings these days.
CHILDS: Well, that's right because in the Gothic cathedrals it was just stones laid on top of each other, which they cannot take any horizontal force at all. They're great in taking gravity loads. But when you get it to be taller and the angle of the roof, the buttresses are there to push it back and hold it in place. And that's what we do today, but we do it by making welded connections that can resist that overturning moment because we just can't, frankly, put buttresses out. They'd go all the way across the streets to be able to support the very tall buildings.
CONAN: David Childs, again, congratulations. Thanks very much for your time.
CHILDS: Well, thank you. Glad to be with you.
CONAN: David Childs joined us from our bureau in New York. He's the lead architect on One World Trade Center, a partner at Skidmore, Owings and Merrill. Transcript provided by NPR, Copyright NPR.