So let's go ahead and get started. First off, a disclaimer, this talk is not about skyscrapers. So, I know you're probably thinking, but the very first slide, it said how to build

a skyscraper, but I promise you this talk is not about skyscrapers. And it's really important that we remember this as we go through the talk. So for those of you who are on time, you're gonna be like really confusing the other people that come in late because we have an exercise to do here. Anytime you see this slide, I'd like you to read it out loud. We're gonna try that right now.

This talk is not about skyscrapers. All right, but when I first started researching for this talk, I did find it really interesting when I started to read the descriptions of the considerations that you have whenever you do skyscraper design and construction. I think it's interesting anyway. So, first skyscraper we're gonna talk about.

Doesn't even technically qualify as a skyscraper, it's the equitable life building built in 1870. But, to be fair, skyscraper is also a term that we've used for very tall horses, very tall men, and even very tall hats. So, I think we can probably give a seven story, 130 foot tall building a pass. Now, the equitable life building was the tallest in the world from 1870 to 1884.

And it was the headquarters of the Equitable Life Assurance Society of the United States, but that's a mouthful, so I'm just gonna call them equitable. Now, they were a life assurance society. They were a life insurance company, is what that really is. So, them being a life insurance company, they were experts at assessing risk.

Now, they had determined that their building was fireproof. We'll come back to that a little bit later. So, its basement housed safes and vaults that were filled with several billions, and I do mean billions in 1870s era money, of securities, stocks, and bonds. So, put simply, this equitable building

was the center of most of the wealth of New York. In the New York financial district, specifically. And it really showed us, this building is gorgeous. And tenants in their building included bankers and lawyers, and it even had an exclusive lawyer's club, which is what you see here. And really, it only had one problem. Can you spot it? It had stairs.

And a lawyer on the seventh floor of the building was not gonna have very many clients if they had to climb up six flights to get to him. So, thankfully, a solution to this problem did exist. A guy by the name of Elisha Otis was a tinkerer. He and his sons, actually. And at age 40, in 1851, he was managing the process

of converting an abandoned sawmill into a bed frame factory. Now, while cleaning up, he had a reason that he needed to get all of his debris up to the upper floors of this factory. And hoists and elevators existed, but they had one really important flaw, which was that if the rope broke, then anything that was on this hoist

was likely broken or dead. Kind of an issue. So, he and his sons designed what they called a safety hoist, and it wouldn't fall to the ground if the rope broke. And he didn't think too much of it. He didn't patent it, he didn't try to sell it, and he didn't even ask for a bonus for designing it. But three years later, the bed frame business was declining, and he was looking to try something new.

So he formed a company to sell his elevators, and he got no business for several months. Now, the neat thing about these elevators is these teeth, right, on the side of the elevators, whenever the rope would break, the spring would release its tension, and these pegs would shoot out into these teeth to stop the elevator from falling. So again, no business for several months.

And then came the 1854 New York World's Fair. Now, he had a great opportunity to demonstrate the elevator in a really dramatic way, and he was a bit of a showman. So he gets up on one of these hoists, and he has an assistant cut the rope, and he's fine. Everybody, it's kind of like NASCAR. Everybody's waiting to see the disaster, right, that's gonna happen, but everything's fine.

And I'd like to point out, too, that this is a charcoal drawing, but there's a photobomb in it. I'm not exactly, I'm not sure what that's all about. So these elevators weren't perfect. They ran on steam engines back in that day, and so that meant somebody had to keep them constantly fueled. But even though it would be a while before they were updated to run on electricity, it was a big deal.

You gotta think about equitable here. It used to be that when you had an office building, because people didn't want to climb stairs, if you owned the building, you made the most money on that investment by renting out the lower floors. So a company would lease the space in the lower floors, and then make all of its employees go up, you know, climb, end up sweaty and a mess

whenever they get up there. Speaking of which, how are those showers this morning, huh? So, now there's a safe way to travel easily to and from these higher floors. And you know, the highest floors also happen to have the perks of being the most well-lit, the most well-ventilated,

the furthest away from road noise. So this literally turned the value proposition for buildings upside down on their head. And all of this was the result of something Elisha Otis didn't even think was that big a deal. I'm just glad he shared it. But anyway, we were talking about the equitable building. You know, the one that was fireproof, and it had billions of dollars in its basement.

This is the Cafe Sauvignon. It was a really fancy cafe in the equitable building. Now, picture that it's January 9th, 1912, and it's just after 5 a.m. And the wind is howling with gusts over 68 miles per hour. And it's making the below freezing temperatures even cooler.

And Philip O'Brien, who was the timekeeper at the Cafe Sauvignon at the time, had started his day by lighting the gas in his small office. And he distractedly throws the still lit match into the garbage can. By 5 18 a.m., the office is engulfed in flames. And the flames spread to the elevators and the dumbwaiter system,

and quickly engulfed the entire building. And the fire department arrived, but as you can see here, it was so cold outside that as they're spraying the building down with water, it's freezing on the building. They literally can't put the fire out because it's turning to ice before it gets to the fire. So the building was completely ruined. And so it was that the building built us.

And so it was that the building built as fireproof was lost in a fire. And history buffs out there might also remember that 1912 was a year that an unsinkable ship struck an iceberg and sank as well. You know, you'd think two disasters in one year would be enough to teach us, maybe we shouldn't be making these grandiose statements anymore.

But again, next skyscraper we're gonna talk about is the Home Insurance Building. It was built in 1885. The architect was William LeBaron Genny. The story goes that Genny left work unusually early one day.

And his wife thought perhaps he was sick, and she rushed to meet him at the door. And she took this heavy book that she had, and she sat it on a bird cage. And inspiration struck Genny when he got there, and he said, if so frail a frame of wire would sustain so great a weight without yielding, would not a cage of iron or steel serve as a frame for a building? I'm not quite sure why it kind of sort of rhymed.

That's very poetic if he really did say that. But we're gonna go with it. So the Home Insurance Building is considered the father of the skyscraper by most, and it was the tallest in the world until 1889. It was built from cast iron columns and rolled iron beams for the framework up to the sixth floor. And then from that floor up, it was steel beams.

Now, the majority of the masonry that was used was actually hung from the framework like a curtain. So in construction like this, the masonry was there to look pretty, to keep the weather out, to keep the people in, that sort of thing. But the heavy lifting was done by the framework. And this made the building drastically lighter and to the tune of about one third the weight of a typical load-bearing masonry building.

So something as simple as a bird cage led to an idea that was gonna revolutionize everything about how we went on to build tall buildings from this point forward. But you may have noticed I said that the majority of the masonry wasn't load-bearing, and since there was still some load-bearing masonry in the building, it left things open to debate.

And so the end result was that if you were from New York, you said, well, you know, the home insurance building really isn't the first skyscraper. But if you were from Chicago, you certainly did think that this building was the first skyscraper. But you know, the interesting thing about this is here are these people in Chicago and they've built this awesome building upon an iron and steel framework, and it's clearly a technical accomplishment.

And more importantly, it's serving needs of their occupants, but it was so easy for people to come along after the fact and sort of debate, well, you know, it's not really that impressive. So this is Leroy Buffington. He doesn't look very happy, does he? Maybe that's because he claimed he had the same idea for this framework sort of design in 1881,

except he didn't build it. He did, however, apply for a patent for it in November of 1887, and it was granted in May of 1888. Now, by this point, the technique's already in wide use. But still, Buffington started a company he called the Iron Building Company for the express purpose of pursuing lawsuits.

Now, this is a flax mill that used iron framing. This was built in 1797. It sort of sounds like prior art to me. But that didn't really stop Buffington from trying to extract money from anyone who was gonna pay. But again, I like, you know, for post-lunch,

this is impressive. I love you people. So the next building we're gonna talk about is the Monatnock Building, built in 1891 in Chicago, Illinois. So there were these two brothers, wealthy brothers. I could only find a picture of one of them, Peter Brooks. But Peter and Shepherd Brooks believed Chicago was gonna be America's largest city.

And you can tell Peter was rich because they don't do oil paintings of people that aren't rich, I find. They hired this guy on the right, O.N.F. Aldis, to be their property manager. And Peter only ever visited Chicago one time. The brothers relied on Aldis to do all of the heavy lifting, figure out what they were gonna do. So Aldis recommended that they retain Daniel Burnham and John Root

of the very imaginatively named Burnham and Root to design this building. Now, Burnham was a pragmatic businessman, but Root was a bit of an artist. He had a flair for the artistic. This is a sketch from 1885 that was drawn by Root. This was, at this time, the building was planned to be 13 stories.

And it had this sort of Egyptian-inspired ornamentation that you can see up here. Now, Peter Brooks was known not only for being very wealthy, but also for being very stingy. And he preferred simplicity. And in fact, he insisted that the artist refrain from any kind of elaborate ornamentation. He said, in fact, he didn't want anything to protrude at all because it was just gonna create a place

for pigeons to nest. He really had a problem with pigeons. So when Root goes on vacation, Burnham, the business guy, has another, just a draftsman, create a simpler drawing. You might imagine that when Root came back from vacation, he wasn't terribly pleased. Here was this artistic work that he had done that was being gutted, essentially.

Now, he did eventually, however, decide to throw himself into the design. And he found a way to kind of get invested. He declared that the heavy lines of the Egyptian pyramids had captured his imagination and that he would throw the thing up without a single ornament. So by embracing this constraint that Brooks had provided, instead of fighting it, he was able to find a way to remain invested

and passionate about his work. So this is the sketch four years later in 1889. You can see Root really, he can't quite give up entirely on a little bit of ornamentation, but he has these little protrusions that stick out along the way, these little bumps that you can see. But Aldus was able to sell Brooks on the idea because these protruding windows

would increase the square footage they could rent. So in fact, the height of the building was calculated by determining how high can we actually get away with building this thing while still having enough room to rent because this was load-bearing masonry. So by the time you got down to the bottom of the walls, these walls were six feet thick. So imagine you keep going higher,

you lose rentable space, you can run it through an equation, figure out how to optimize. So Chicago also had soft soil, so they had to devise a special raft system that kind of floats the building on top of the soil. So this is the finished product. It's 215 feet tall, 17 stories. It was the tallest of any commercial structure

in the world at the time. Now they knew that the building was gonna settle. They designed it to settle eight inches, but by 1905 it had settled that much and quite a bit more they ended up having to reconstruct the first floor. By 1948, it had settled 20 inches, and so they actually had to put a step down. So to get into the building now, you step down to go in because it's gradually sinking.

And guess what? It's found to be sinking in 1967. They forgot it already was, I guess. So profitability's a really important factor to consider, but it can't be the only thing that you consider while you're building your building. Again, the next skyscraper we're gonna talk about

is the Fuller Flatiron, 1902. So during the construction of the monotonic, John Root passed away. Daniel Burnham was still in business. He had DH Burnham in company, and he partnered with a guy by the name of Frederick Dinkelberg to build or to design

the Fuller Flatiron building. The Fuller Flatiron was originally supposed to be called just the Fuller Building after the recently deceased George A. Fuller. He was kind of a big deal in the architecture community. But locals called it the Flatiron. Now, I assumed, oh, it's because it's like iron. It's made out of iron or something to that effect. But as it turns out, it was much simpler than that.

The building looked like a flatiron. And at the tip, it was only six and a half feet wide. The shape of the plot of land they had, this triangular plot of land, it necessitated a different kind of shape for the building. And if the monotonic required walls that were six feet wide at the base, you might imagine that's not gonna work whenever you're six and a half feet wide

for the entire building at the tip. And it was only 16 stories tall, so this is even a taller building. So at this point, that's obviously not the case. You can see that they're not six feet wide, they're not six feet wide walls. So since it was better to have an oddly shaped building than half a building, Burnham and Dinkelberg had adapted their approach

so that they could fit the space that they were given. And this meant choosing some new materials, and in this case, it was all steel. It was not masonry at all. So the flatiron was built on an all-steel frame. Now, if you look at these photos, you might not be terribly surprised to hear that the locals were calling this building Burnham's Folly.

And in fact, they were actually taking bets on how far the building's debris was going to blow when the building toppled over during the windstorms that would hit. So, but you know, there was an engineer, his name was Corden Purdy, and he was involved in this project, and he had designed bracing that had already been tested to withstand four times the wind this building was ever gonna encounter.

And so it was after this building went up during the first windstorm that hit very shortly after, it was 60 mile per hour winds, and the tenants were saying they couldn't feel the slightest vibration in the building, and not only that, one even said that the filament in his light bulb didn't even quiver whenever they had this windstorm. So this didn't surprise the engineers one bit, they had run their tests, they knew what was going on,

but it really blew everybody else away. But again, so this is a twofer, we're gonna talk about two skyscrapers at once, they both went up in New York, and we're gonna talk about 40 Wall Street and the Chrysler Building. Now, H. Craig Severance and William Van Allen were formerly partners at another architecture firm,

and they were very different personalities. Van Allen was, again, an artist, he was the type of guy that liked to hang out with other architects and discuss the finer points of design. And Root was very much like him, there's this pattern you see of these kind of pairings of a business person and an artist.

But Severance, on the other hand, he spent his time with the business folks, and he was drumming up sales. You might be able to tell here, humility wasn't exactly his strong suit. And he didn't really have a particular passion for architecture as art. But still, whenever the trade magazines would all refer to Van Allen as this great designer,

this very impressive person, and they didn't really mention Severance at all for the buildings that they designed together, he took it personally, and their partnership, as you might imagine, ended badly. And then, to make things worse, they found themselves in competition with one another. So, Severance had been commissioned to design 40 Wall Street, but Van Allen was commissioned

to design the Chrysler Building at the same time. Now, you're probably already familiar with the Chrysler Building, but I talk to people regularly that don't know what I'm talking about when I say 40 Wall Street, so maybe this will actually help. We call this the Trump Building today. Back then, it was known as the Bank of Manhattan Trust Building.

So, Severance had assembled a bit of a dream team. It consisted of his associate, Yasuo Matsui, and consulting architects, Shriven Lam, to design 40 Wall Street. Now, Walter Chrysler had Van Allen design the Chrysler Building for his car company, but he paid for it all himself because he wanted to leave the building to his children one day. And he was obsessed of every single detail

of this building because he later referred to it as a monument to me. So, the Chrysler Building was announced a month earlier than the building Severance was working on, so you might not be terribly surprised, then, that the 40 Wall was announced as a bit higher, right? So, in October of 1929,

Severance is visiting the site of his construction, and his building's just about to catch up with the Chrysler Building, and he's feeling pretty good about things because Chrysler Building's slowing down now. They're putting these domes on the top that you probably would recognize, and they can't go much higher. Now, Chrysler was already in the process

of drumming up press for his building, so he was announcing that the steel work was complete, which would have made the Chrysler Building the tallest one in the world at the time at a revised height of 850 feet. But Severance wasn't really worried. He had already put in motion plans to build higher than announced, and this was once. So, the month was filled with all sorts of announcements from other builders, and everyone was claiming

that they would build something larger. In fact, there were people saying, well, there's nothing really stopping us from building a building that was two miles tall. So, Van Allen was silent. He, Chrysler, and a very few other people knew that they were gonna build a lot higher than anyone was expecting. So, in the third week of October, Severance hears about the sighting of a 60-foot flagpole

at the top of the Chrysler Building, and so he raises his plans again. And this was enough when they leaked this information to the press to declare that the Bank of Manhattan Trust Building was, in fact, going to be the one that would top out the tallest. And then, you know, it just, it made sense, right, because the Chrysler Building couldn't go much higher. And so, they knew that the Chrysler, or the Manhattan Trust Building was gonna be 925 feet.

Chrysler Building would be 905 feet. And this was all including that flagpole, only the flagpole wasn't a flagpole. The flagpole was just one part of a five-part, 185-foot, 27-ton steel spire that Van Allen named the Vertex.

And he had had it built in the off-site in all these five pieces, and then he shipped each part separately to the building, and then they hoisted them into the dome's fire tower on the 65th floor. So, then they partially assembled them, hoist the base up, rivet all the rest of the pieces in place in about 90 minutes. So, Van Allen and Chrysler go to bed this evening knowing they have the tallest building in the world.

But, the best part is nobody else actually noticed, because from the ground, this stuff kinda just looked like a really tall crane or something attached to the building. And so, they just kept quiet, because, you know, severance can keep on going if you want, so let's just keep it quiet for a little while. And so, when 40 Wall Street tops out in November, the New York World runs with this headline,

and they aren't talking about the Chrysler Building, but they're talking about 40 Wall. And four days later, this kind of uninteresting trade magazine called the Daily Building Report from the Dow Service, it's normally running things like what are the costs of building materials all around the country, so you can optimize for that kind of stuff. They break this news, this dramatic news,

that the Chrysler Building's over 238 feet taller than anybody really knew they were building. And so, after all was said and done, the Chrysler Building was towering over 40 Wall Street by over 100 feet, and it became the tallest man-made structure that was ever built. This beat out even the Eiffel Tower, which had been the tallest man-made structure up to this point. But both of these buildings cost a fortune.

I mean, you got 13 mil on one side, 14 mil on the other. Think for a moment about how much extra expense was incurred on these buildings, and just because they were trying to win against a rival. To make things worse for the winner, Chrysler refused to pay Van Allen his 6% design fee after they finished this work.

That would have $840,000 that he stiffs this architect, because the architect hadn't quite been bright enough to enter into a legally binding contract when he received the commission to build the Chrysler Building. And you know, Chrysler would have paid anything up until the point this building was completed and he had won the title to reach this height, but after that it just didn't really seem like it was worth it.

Van Allen had to sue him to get paid, which ended up making him a bit of a cautionary tale to other architects. And in fact, no major studies have really been devoted to the state, to Van Allen's work, and he's little known in the history of architecture. On his death, the New York Times didn't even publish his obit. Again, so another neat skyscraper

is the Empire State Building. Again, we're talking about New York here. Back in August of 1929, this is during the construction of the two buildings we just discussed, rumors started circulating that a new developer was gonna take ownership of the site of the Waldorf Astoria Hotel.

Now Al Smith was the former New York governor that was running against Herbert Hoover for the presidency and he had invited John Raskob to chair the Democratic National Convention after Raskob had been running his campaign. Well, Raskob was VP of finance for GM and until 1928 when he got ousted by a guy by the name of Al Sloan,

who was a supporter of Hoover and claimed there was a conflict of interest here, so we ousted him out of the company. Well, Raskob's like, okay, fine, whatever. He sells his GM stock. He wants to finance a building. He creates the Empire State Company and he hires Al Smith to be the president of it. So Al Smith is a politician, right? He has a flair for the dramatic.

This is how he announced that he was gonna be the president of the company and that he was gonna build this building and of course, he announced that it was gonna be an 80 story skyscraper, the tallest in the world. But again, this is around the same time that everybody else is making these grand claims of like two mile tall buildings, so nobody's paying attention. So speaking of these months, remember Shreve and Lamb,

they were the consulting architects that were brought on to work on 40 Wall Street. During the same time, they teamed up with another guy by the name of Arthur Loomis Harman and by, I think it was October 2nd, 1929, they were already showing scale models of this new building, the Empire State Building, to Raskob.

And I think that's really interesting because these other buildings hadn't even been done so they sort of had some insider information about what was going on. Now Lamb was, again, Lamb was an artist, very much like Van Allen and John Root before him. And his partnership with Shreve was very much, Shreve was the business guy.

Now, the thing about this is, he was also pragmatic enough to know that there were certain concessions he was gonna have to make, even though he had a flair for the artistic. And you know, he had a tight deadline and that was gonna be the primary constraint that he was gonna have to deal with. Now, initial drawings for this building

were created within two weeks and final design was region four, this is like really fast. And one of the things they did that was really interesting is instead of designing from the bottom up, they designed from the top down. They set a standard for light in the interiors and this was the thing that they said they weren't gonna compromise on. They wanted to place a standard on how pleasant it would be to work in the spaces

that they were building. And you know, Lamb had his priorities straight. He understood that certain things had to be constants and everything else was gonna have to shift around those things. He wasn't willing to sacrifice lighting, ventilation, anything else that was gonna make the property valuable and appreciated by those people who mattered. Well, who matters?

They're the present and the future occupants of your building. They're people like her, they're people like him, they're people like this guy because if the building can't be maintained, it's not gonna be very good for very long. Occupants can come in all shapes and sizes. But one thing is for sure, just because someone is big, strong, loud,

and they wanna use your building to make themselves bigger and stronger and louder, that doesn't mean that you should put their needs above the greater good. So one reason the building's designs took shape so quickly was that they were able to use parts of designs that had been done before. This is the Reynolds Building in Winston-Salem, North Carolina. It was designed by Sreevan Lamb previously.

And this is Carew Tower in Cincinnati, Ohio, designed by another firm. If you look at the scale models side by side, you can see that there were aspects of the design that were sort of swiped from both of these other pre-existing designs. And it's great to be able to reuse previous work because it can make your work go much faster. So fast forward to November of 1929.

Al Smith has just announced that they've also bought the adjoining land to the Waldorf Astoria, which of course the news people are now recognizing, well, this means they're building higher. Now, Sreevan Lamb and Harmon, they all wanted to keep the height down to be practical because the higher you went, eventually, you even had to have people get out and change elevators, right?

They can't just ride one elevator up to the top. They have to get out, walk around, and change elevators. That's fine and good, but Raskob's the guy that's paying for this and he wants to add more height to Empire State. And so the next day, Al Smith, in his typical fashion, announces that they're gonna add five more floors. He announces the new title, the new total's gonna be 85 stories and 1100 feet.

That's an overestimate by about 50 feet, but you know, he's not the tech guy, it's okay. All right, so I love this, though. I love that this is what the actual architects are saying. We wanna do sound development of usable space. So John Raskob, he's sitting in his office and he's looking at this scale model that they've provided

and like every client ever in the history of ever, he decides he knows exactly how to solve this problem. And what he reportedly said at the time is that this building needs a hat. Now, he didn't mean a literal hat. What he meant was a mooring post for zeppelins to be able to dock above the streets of New York City and let passengers off at the top of Empire State

so that they can then go down the building. And it was gonna be so much better than the Chrysler building spire because this had a good purpose and it was gonna need another 200 feet. And you know, this is gonna let them stay true to Shreve's promise that we're gonna do the sound design of usable space. But you'll notice how Al Smith just happens to mention the final height of the building in his announcement

about this new development. Now, nevermind the feasibility of docking a zeppelin at this height above New York City or what was gonna happen when the zeppelin got caught by some wind gusts and needed to maintain even keel by dumping several hundred gallons of water on the people below. I wanna remind you now, if you don't remember this from physics,

water weighs about eight pounds a gallon. And so we're talking about well over a ton of water being dumped on citizens below the building. But Raskov had to build the tallest building, none of this mattered. Now, this plan was going to add $750,000 to the cost of this building. But because it had marketing appeal and because everybody was so enamored

with flight at this era, the architects had really no say on it at all. Raskov and Smith were determined it was gonna happen and so this frustrated Shreve, he wanted things to be practical. But in the end, they still had to go with it. Now with the designs completed, it was time to start building and the interesting thing about building is I don't care if you design from the top down,

but you definitely need to build from the bottom up. When you build, everything that you build has to sit on top of something else. Now, your definition of bottom might change depending on what you're building on top of. But the only way to make sure that the structure is going to be sound is that it's sitting on something else that's already sound.

But it's important to be honest with yourself. If you've built an entire ecosystem and your own building as well on the top of another person's building while considering that person's building the bottom of yours, you can't really complain when the bottom gets yanked out from under you. By the way, during the act of building

the Empire State Building, the real heroes are the steel workers that were putting in work. The ways in which they had to do their work were extremely dangerous, extremely stressful. They were always operating under tight schedules and they didn't even always have time to put in proper safety nets. And sometimes, even the supports that they could build

didn't seem terribly fit for purpose. Now, you know, sure they got to have lunch but they sometimes had to have the lunch in the office, as it were. And you know, construction of the Empire State Building, it started on March 17th, 1930 and it went for 14 months. This building was rising at a rate of four and a half stories per week

which was a record speed. So 14 months after construction began, building opens. And it was gonna have the world record for tallest skyscraper for the next 40 years. So notice how short-lived Van Allen's record was after all the work and the effort that they had put into it. Now, they completed this monumental feat

with only five deaths. And you know, five deaths on record when you look at the conditions these people were working in seems pretty low, like really. But even one life lost is too many. Next one we're gonna talk about is the United Nations Headquarters.

Again, we're in New York. Now the interesting thing about this building is compare this building to the height of the previous building and this building is actually like half the height. And yet it took longer to build. It was constructed from 1948 to 1952. That gives you some idea how quickly things moved on the Empire State. Now the big thing about this building is

it's all windows. They had decided they wanted lots of light and so everything had to be sealed windows. But you know what else is built with lots of sealed windows? A greenhouse, right? So the problem is that with light comes heat and if you want the light but you don't want the heat you have to figure something out. Because it really doesn't matter if your building is super pretty

if nobody can actually stand to be in it. So the solution to this had started earlier and it started in response to a problem that was encountered by a printing company in Brooklyn. Now the printing company was actually having a problem with their paper getting wrinkled by humidity. And so then when they would ink the paper there would be wrinkles and they would cause the ink to come out and misalign.

So a fellow had already come up with a solution for this his name was Willis Carrier. He was an engineer that had worked to basically come up with a way to remove the humidity from the air and happened to have the side effect of also cooling the air. And it worked by blowing air over a set of coils filled with coolant. So he called it the apparatus for treating air but we later came to call it air conditioning.

Apparatus for treating air. So the first space to use a similar kind of technique to cool for human comfort was actually the New York Stock Exchange. And the guy that had designed that system was Alfred Wolf. The thing about the system that was used there was first off it was very expensive and it was also very heavy.

This device actually weighed 300 tons. So in 1922 Carrier had improved on his original design. He had added a centrifugal chiller. And what this meant was that it was simpler, it was smaller and it was most importantly way more cost effective. So without this a building like the UNHQ wasn't gonna be able to exist.

And this is really important because yes the technology existed before but it's a big difference between it existing and being accessible. But again, now we're gonna talk about the Willis or we may have known it as the Sears Tower at one point in Chicago. Fazlur Rahman Khan was the architect for this building.

And he was actually a structural engineer tasked with building an office complex for Sears Roebuck & Company. And they wanted to host all Chicago employees in one building. So this was gonna have to be a very tall building. Now Chicago's known as the Windy City and it's not really known as the Windy City because of the gusts off Lake Michigan but the gusts from Lake Michigan

can batter the city with winds of over 55 miles per hour. Now the taller a steel skeleton building gets the more susceptible it is to bending in high winds. And so this, it creates a swaying motion that gives you a sensation not unlike seasickness. You can get seasick on the top of a very tall building. So Khan had developed something he called

a tube structural system which doesn't look much like a tube but in theory it really was. It took the skeleton that we were used to, the steel skeleton, turned it into an exoskeleton pushing everything out to the edges. And not only did this give you better resistance against wind but it also reduced the building's weight even further and it opened up more use of the floor.

You had to have these large floors like open office floor plans for instance. We all love those. And the thing about this is unlike this lobster who's exoskeletons not winning him any beauty contests, Khan's exoskeletons opened up new avenues for design of buildings that frankly turned buildings into art and you were able, evolutions of this design were able to become very, very impressive over time.

And the important thing here is that it wouldn't have been possible to build this high if we hadn't built up a thick shell to guard against the wind. Now the Sears Tower was built using Khan's bundled tube structure. It's exactly what it sounds like. It's the same kind of tube construction but a big bundle of them.

This was nine separate buildings of various height and it used the same construction bundled together. The end result was that even with wind speeds of over 55 miles per hour, the top of the Sears Tower only sways six inches. So it's interesting how multiple small structures working together can be more resilient than a single large building.

But we're almost done, two more. First one we're gonna talk about of these two is Taipei 101. It was completed in 2004. It's built in Taipei, Taiwan which you probably would know from the name. Taipei sits near the Pacific Ring of Fire which is the most seismically active area on Earth.

It gets hit by an earthquake about twice a year and earthquakes are very different than wind shear. Earthquakes, they have a very strong effect because they affect the foundation of a building. So an earthquake can literally break a large building and this means it's pretty important to test against breakage before you erect a large building on a foundation.

It turns out that spaghetti models, like you might have built in science class at one point, they're actually, they model steel very nicely. They bend and break under similar conditions, similar characteristics. And so this is how they test them. This is so awesome, like I wish this was my job. Seriously, you get to play with these models all day?

Now look, the structure seems mostly intact, right? But if this had been a real building, that top floor would have fallen down and killed everybody inside. The structure was too rigid and it transferred too much of that vibration to the top floors. The industry, by the way, has a term for this kind of failure. So this is fun.

It turns out that the only way that you can actually assure a lack of failure is to test for all modes. But the only way to know of all modes is to learn from a failure that actually happens. And so it's not possible to be absolutely sure that any given structure is gonna resist any loading that could cause a failure. All we're really doing is figuring out that it's acceptably unlikely.

Think about that the next time you're on the 30th floor of a building. Someone's in charge of deciding what's acceptable. So it's really important that we test to ensure catastrophic failure is acceptably unlikely. And hopefully set a good bar for that. Right. So the designers of Taipei 101,

they made it rigid where it had to be and flexible where they could afford to be. And this is a floor plan, a typical floor plan for 101. You can see these yellow dots on the map here. They represent 36 rigid steel tubes including eight mega columns in red. These are all pumped full of concrete.

And then every eight floors, there are these outrigger trusses that are essentially like big rubber bands around the building that allow the building to shake, essentially. Now on March 31st, 2002, a 6.8 magnitude earthquake hit Taipei. And Taipei 101 was still under construction. It destroyed smaller buildings, it toppled two cranes from the tops of this building.

But the construction ended up resuming without incident after an inspection said everything was fine, there was no structural damage. In fact, the engineers said, during a quake, Taipei 101 is the safest place in town. So you'd be surprised how flexible it turns out you can afford to be. Now that flexibility is great for withstanding a quake,

but you might imagine that making a building that's kind of strapped together with rubber bands has negative effects in the way that you can resist wind. So if every time the wind gusted, everybody got sick, you probably wouldn't have any tenants. So it actually has three tuned mass dampers. And this is the biggest one. It's suspended from the 92nd to the 87th floor, and it weighs 728 tons.

And what happens is, this is during a typhoon last year, what happens is it swings in the opposite direction to sort of maintain against the wind so that when the building is swaying, it's kind of pulling back in the opposite direction. And you know, it's really good when winds pick up to have something at the top that's pulling for you.

This talk? Right. And most importantly, I want to talk about the Burj Khalifa. It was built in 2010. And everything that we've learned so far has been refined and improved and applied to make this building possible. But that's not actually what I want to talk about when it comes to the Burj Khalifa.

So after the attack of September 11th, it was actually discussed that maybe we wouldn't be able to build any super tall buildings anymore because the problem becomes one of evacuation. In an evacuation situation, stairs are really the only option. And it turns out that walking down stairs

is almost as difficult as walking up them. And at twice the height of the former One World Trade Center, Burj Khalifa, they needed a plan to ensure the safety of people that were gonna be inside in the event of any kind of accident, really. And you know, the building had a naturally fire-resistant concrete core, which, you know, it helps. But even so, as you build higher and higher,

more and more people need to walk further and further to get to safety. So the big question then is how do the people that are in the Burj Khalifa get out in an emergency? And the answer that surprised me is they don't. Turns out that it's not just enough to give only one option to people who are in danger to leave the building.

So what was done is that refuge rooms were built on the mechanical floors of the Burj Khalifa. They were built from layers of reinforced concrete. And they had fireproof sheathing. And the walls of these rooms, they can withstand the heat of a fire for up to two hours. And each room has a dedicated supply of air that's pumped in from fire-resistant pipes.

And by creating these safe spaces that the people in danger are able to go, the architects make it more likely that people are gonna survive a catastrophe. These spaces are every 25 floors or so. And that's important because it doesn't matter if the safe spaces exist if they're too inaccessible

or if they're too risky to get to. Now, in a fire, you probably have heard that it's not usually the fire that kills you. It's the smoke inhalation. Well, if the route to a refuge room is blocked by smoke, then that room is no good. So the Burj Khalifa, if anything activates a fire detector,

a heat sensor, a water sprinkler, a network of high-powered fans kick in, and they force clean, cool air through these ducts into these rooms to push the toxic smoke out of the stairwell so that the route to the safe room is clear. And it's important not to just provide the fresh air and the safe space, but to actively work to push out toxic elements in your building.

And of course, none of this is a substitute for rescue workers. The rescue workers still need to come to the aid of those people who are in the refuge rooms. Safe place is just a place for people to go while there are people actively working to resolve the issue and resolve the emergency. Because anything worth building is only worth building

because of how it impacts people. Thanks, this was not a talk about skyscrapers.