Skyscrapers: An Upward Journey

Durability, convenience and beauty have no defined shape. That’s why skyscrapers are a medium for dreaming. Listen to the latest episode of Trailblazers and learn how far we’ve come. And where we’re going.
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As space on our planet comes at a premium, building “up” is the natural solution. But how high can we go?

From a century that saw buildings play out the dreams of titans and created extraordinary cityscapes, these towering columns were symbols of prosperity–or occasionally, bankruptcy.

If innovation is only inhibited by our imaginations, perhaps even the sky is not the limit. Skyscrapers are the monuments of human potential and we’re still building.

In this episode:

● The race for the tallest building in the world (0:00)

● A common object inspires steel framework technology (4:26)

● Boomtown, USA (7:05)

● Tall egos, tall buildings (9:45)

● Innovation and glass (13:55)

● The Middle East reaches the clouds (16:29)

● Records are meant to be broken (20:36)

● Architecture by software (21:04)

● The environmental impact of big buildings (23:05)

“With technology going hand in hand with the process of urbanization, we think of New York at the turn of the 20th century, of immigration with a gigantically expanding population. All of those kind of surging business interests express themselves in the value of land and the capitalization of the value of that land in tall buildings.”

— - Carol Willis founder of the Skyscraper Museum in New York City

Guest List

  • Carol Willis is the founder, director, and curator of the Skyscraper Museum, and an adjunct associate professor of Urban Studies at Columbia University.
  • Bill Baker is a structural engineer known for engineering the Burj Khalifa, the world's tallest building/man-made structure.
  • Scott Johnson is an architect, lecturer and the author of Performative Skyscraper: Tall Building Design Now.
  • Neal Bascomb is the author of Higher: A Historic Race to the Sky and the Making of a City.

Walter Isaacson: It’s October 23rd, 1929, the height of the Roaring Twenties in New York. And 900 feet above the streets of Manhattan, the Vertex is about to be unveiled to an unwitting public. Very few people know about the Vertex or even what a Vertex is. It’s a 125-foot-long metal spire and it’s been constructed in total secrecy inside the walls of the then still under construction Chrysler Building. An icon of the New York skyline today, the Chrysler Building was at the time a participant in a furious race to the heavens; its competitor, the Bank of Manhattan Trust Building at 40 Wall Street. The builders of each were determined that their skyscraper would be the tallest building in the world. And what made the competition even more heated was that the two visionary architects behind the buildings, William Van Alen for the Chrysler Building and H. Craig Severance for the Manhattan Bank Building, were former partners turned into bitter rivals.

Walter Isaacson: All of New York seem to be watching as the two men duked it out, altering their plans in mid-construction, each determined to triumph over the other by constructing a taller building. Van Alen kept his secret weapon under wraps until the Bank of Manhattan Building’s height at 927 feet was officially announced in the newspaper along with the claim that his archenemy Severance had won the competition. And then on October 23rd, in a feat of incredible engineering and daring, his workers removed the pieces of the Vertex from inside the Chrysler Building and assembled it in midair. The Chrysler Building was now the tallest building in the world, but Van Alen’s triumph would be bittersweet.

Walter Isaacson: As monumental as they were, the Bank of Manhattan Trust Building and the Chrysler Building couldn’t escape the fact that the very next day after the Vertex was raised, the stock market crashed. The Great Depression had begun. These monumental skyscrapers, soaring symbols of the Jazz Age, were about to nearly bankrupt their owners, but the impression that they left on the public would define cities for a century.

Walter Isaacson: I’m Walter Isaacson, and you’re listening to Trailblazers, an original podcast from Dell Technologies.

Speaker 2: Now America is a land of mighty cities.

Speaker 3: While things like housing, industrial development …

Speaker 4: … homes and schools, stores and theaters and palatial hotels …

Speaker 5: … such a scene suggests, too, the steady pulse of urban change.

Speaker 6: A monument to our passion for things big and great.

Walter Isaacson: Skyscrapers have always brought together cutting-edge technology, incredible feats of engineering, huge amounts of money, and at times even bigger egos. Ever since the first buildings of 10 stories or higher were built in the 19th century, they’ve captured the public’s imagination and have become icons of the cities whose skylines they dominate. This century has seen them reach even higher, with the first one-kilometer building scheduled to be completed next year. And while they’re still highly expensive trophies for cities like Dubai who want to show off their wealth to the world, the newest skyscrapers are more than just symbols. They’re the cutting edge of innovation, leading the way for sustainable technologies in an era when our cities keep getting bigger. And if you believe the story, the technology behind these giant buildings in the sky all began with a birdcage.

Walter Isaacson: There was a fundamental problem if you wanted to build a structure more than four or five stories tall, and that was walls. Up until the late 19th century, buildings were held up by their exterior masonry walls. That meant the taller the building, the thicker the walls had to be in order to carry the weight. When a Chicago architect by the name of William Le Baron Jenney was charged with designing the 10-story Home Insurance Building in 1884, he was eager to find a new, lighter way of construction. As the story has it, Jenney returned home from his labors one evening. His wife stood up to welcome him, laying down the book she was reading on top of a birdcage in the family salon. Jenney was immediately struck by how this light structure could easily support the weighty, hardcovered tome. And he cried out, “If this little cage can hold a heavy book, why can’t an iron or steel cage be the framework for a whole building?” The age of the steel-framed skyscraper had begun.

Carol Willis: Steel allows buildings to have very small points on which they come down into the ground, down into the foundations that stabilize them.

Walter Isaacson: Carol Willis is an architectural historian and the founder, director, and curator of the Skyscraper Museum in New York City.

Carol Willis: That point support of a metal grid instead of a big, thick bearing wall made of brick or stone is the way that buildings become not just taller but more open in the space and creating the interior floor space. So without steel skeleton technology, going higher than about 10 stories is really not feasible or economic, even though taller buildings than that existed, for example, in Chicago, the Monadnock Building, which was about 14, 15 stories tall, but at its base in 1891 had 12-foot thick masonry walls.

Walter Isaacson: The word skyscraper, which was originally coined in the 18th century to refer to particularly tall race horses, starts being used to refer to these high, steel-framed buildings. And although the first skyscrapers were built in Chicago, it’s in another American city that they truly took root. By the beginning of the 20th century, New York City was a boom town, and crucially its most coveted land was in Manhattan, an island of very limited dimensions.

Carol Willis: So with technology going hand in hand with the process of urbanization, we think of New York at the turn of the 20th century, immigration with a gigantically expanding population, all of those surging business interests expressed themselves in, well, the value of land and the capitalization of the value of that land in tall buildings.

Walter Isaacson: To make the land pay, as developers of the time said, they had to squeeze more office space out of relatively small footprints. There was nowhere to grow but up. By the 1920s, skyscrapers weren’t just a way for developers to squeeze out some extra dollars. In New York, they’re representative of a whole swinging post-World War I attitude. And they started to go up in droves.

Neal Bascomb: Right about the 1920s really came to fore, they exploded onto the scene.

Walter Isaacson: Neal Bascomb is the author of Higher: A Historic Race to the Sky and the Making of a City.

Neal Bascomb: Prior to that you would have, in New York at least, a new building go up every 10 years that would raise the height level, but it was only in the 1920s with America really coming into its own after World War I, this idea of American greatness, the stock market mania, real estate prices were shooting through the roof. There was all this mania over being faster and contests and gambits to go higher. And so in New York, that really became a focus. You have, almost on a weekly basis, developers announcing buildings that are going 800 feet, 1,000 feet, 1,500 feet high, even though many of them were just dreams and illusion. But there was this stir and momentum that came with the Roaring Twenties for New York in particular to put its mark on the world, and they were going to do that with skyscrapers.

Walter Isaacson: And while the motives were supposedly financial, there was always another element at play whenever someone set out to build the tallest building in the world.

Neal Bascomb: Building of them, yes, is a financial decision, but for the developers, for the builders like Walter Chrysler who were putting their names on these buildings, it was about a personal statement. It was about ego, it was about hubris. It was about making the world know what a success they were. And so that’s why you have the Chrysler Building. Walter Chrysler said very early in the construction of his building to his architect, William Van Alen, “I want to build a monument to me.”

Walter Isaacson: Add to that the rivalry between Van Alen and H. Craig Severance, his former partner and architect of the other tallest building in the world, and you have the makings of a very personal battle being waged on Manhattan’s streets. A dispute over who deserved credit for their buildings had split up the successful team years earlier, and there was no shortage of bad blood between them. Newspaper readers ate it up.

Neal Bascomb: The public could not help but be aware of this race, because almost on a daily basis, they were tracking the progress of these buildings. Sudden announcements from the architect saying that they were going to go higher, and ultimately at one point in October naming the Bank of Manhattan Building as the winner of this contest, only to be surpassed by first the Chrysler Building and then the Empire State.

Walter Isaacson: Ultimately, the Chrysler Building would only wear the crown of the world’s tallest for a little over a year before the upstart Empire State Building came along and surpassed it with startling speed. Ironically, while Van Alen’s Vertex spire edged it out over the Bank of Manhattan Building, it was a very of its time zeppelin docking station erected on top of the Empire State Building that caused it to surpass the Chrysler Building. The whole thing was as much of a stunt as the Vertex, and no airship ever actually docked there despite a widely circulated fake photo. When the stock market crashed, the economic hopes of these buildings crashed along with it. Famously, the Bank of Manhattan Trust Building, the bronze medalist in the New York City height wars, would be sold off for less than the cost of its high speed elevators. These days, it’s known by the name of the developer who bought it in the mid-nineties for, he claimed, only a million dollars. Its new name: the Trump Building.

Walter Isaacson: Whether they were financial successes or not, the skyscrapers of the early 20th century helped define and still do what a modern city looked and felt like.

Neal Bascomb: The building of these skyscrapers are integral not only to our vision of what New York is, so you can’t drive towards Manhattan without seeing these tall needles, and that’s your image or idea of New York, but the skyscrapers were also integral in the development of the culture of New York because they allowed for a density that had never been seen before. So you have these buildings 68 stories high, 72 stories high, filled with workers. It changed the way that people worked, it changed the density, it changed the vibrancy of the city. And so the skyscrapers are every bit as much a part of New York and what it is than anything else. It’s part of what makes these cities interesting, and you see it in New York today where developers are going higher and higher and higher, and people are still captivated by that.

Walter Isaacson: The art deco skyscrapers of the 1920s and ’30s still define Manhattan as we know it, but it wasn’t until after the Second World War that the truly modern skyscraper came into being as technological advances allowed for tremendous innovation in the way they were built and looked. The exterior of a building, called curtain walls, long removed from the duty of holding up the structure, started to be built with steel and glass. Carol Willis.

Carol Willis: A great advance came after World War II when welded steel, which is much stronger in its joints, makes more rigid joints, was able to allow architects and engineers to make those steel frames lighter than they had been when they were riveted by crews of riveters who had red hot steel rivets, like bolts, that they drove into the holes of the steel I-beams of the frame of the building. The advance of steel skeleton construction after World War II made buildings that were lighter and stronger, and they also allowed for the advancing technology of glass and glass curtain wall, which changed dramatically the appearance of buildings from the kind of stone mountains that you see in the 1920s and early ’30s in New York buildings, like the Chrysler Building or the Empire State Building. And then in the postwar period, these glass boxes where there’s, as we call it, a curtain wall of glass, like a membrane that just separates the inside and the outside so that the visual connection from the interior of the building is no longer through a fixed window.

Walter Isaacson: Some of the more famous buildings from that era are the headquarters of the United Nations and the Seagram Building in New York City. 60 years later, they still look remarkably modern. Over the second half of the 20th century, other prosperous cities began to follow New York’s lead. Hong Kong, an island city like Manhattan, underwent a building boom in the 1970s, leading to it having the world’s largest concentration of skyscrapers, with over 8,000 high rises in its greater urban area. When Dallas was flush with oil money in the 1980s, the glass and steel towers went up. And now it’s the oil-rich metropolises of the Middle East that are fueling the new skyscraper boom.

Bill Baker: When we were designing what was originally called the Burj Dubai, now called the Burj Khalifa, the remit from the client was the world’s tallest building.

Walter Isaacson: Bill Baker is a structural engineer at the Chicago firm Skidmore, Owings & Merrill. He’s best known for engineering the Burj Khalifa, which since its opening in 2010 has held the crown of the tallest skyscraper in the world. When Baker and his team took their original 518 meter design into their test wind tunnel, the structure couldn’t stand up to the high winds it would face in the desert. Wind is perhaps the biggest challenge tall buildings face. When high winds encounter tall buildings, the gusts create a swirling pattern called a vortex, which can be highly destabilizing.

Bill Baker: One of the things we like to do, which enables us to do these very, very tall buildings, is we like to do what we call confuse the wind. So if you have a building that’s of, say, a square plan that’s uniform from top to bottom, you can get fairly large vortex shedding forces, because the vortices will be organized from top to bottom. And the analogy I like to use is like a child on a swing. If you have a child on a swing and they kick their feet and they kick it at the harmonics of the swing, they go quite high, even though all they’re doing is moving their feet. But if you confuse the wind by changing the shape of the building, either what it looks like in plan or the width of it, or you put holes through the building, or many other things you can do, what you do is you confuse the wind. And so going back to the analogy of the child and the swing, it’s like instead of the child having two feet kicking at the same rate, the child has maybe a dozen feet and they’re all kicking at different rates. And you can imagine the swing would go nowhere. We call it confusing the wind.

Walter Isaacson: The innovation by Baker and his team was a new type of structure they called the buttress core. Over the decade, firms like Baker’s had iterated on William Le Baron Jenney’s birdcage-inspired steel skeleton. Chicago’s Willis Tower, formally known as the Sears Tower, is what’s known as a bundled tube skyscraper. Like it sounds, it’s built out of several enormous tubes bundled together to resist wind and seismic forces. To build the huge Burj Khalifa, Baker designed a new variation on the bundled tube, one that allowed him to build way higher than he had ever imagined.

Bill Baker: The middle of the building where the three wings come together is where all the elevators and some of the stairs are, and a lot of the utilities for the building are in that central area. We call that a core, and in the Burj, it’s a hexagonal shape. So we had this core in the middle, but the core in the middle around the elevators and like was great for torsion, but it was too slender to go to great heights, so it needed to be stiffened. So what we ended up doing, we put walls down the corridors coming off of this core, and on the three wings, to buttress it, just like the buttresses on a Gothic cathedral.

Walter Isaacson: In the end, thanks to this hyper-stable new structure, they were able to build the Burj Khalifa a whole thousand feet taller than the 1,700 originally planned. That’s approximately the size of one extra Eiffel Tower that they were able to add on. At 2,700 feet total, the Burj Khalifa was the tallest building in the world when it opened in 2010. And amazingly, it still holds that title nearly 10 years later, but that record may soon be broken. The tower most likely to steal away the crown is the Jeddah Tower, which if successful will be one kilometer high, over 3000 feet. It’s scheduled to rise over Saudi Arabia sometime next year. If Walter Chrysler saw the Chrysler Building as a monument to himself, one can only imagine what he would think of that.

Walter Isaacson: While technological advances have allowed buildings to grow taller, they’re making an impact in other, perhaps more important, ways as well. Software has completely reshaped the way architects approach design. In the early 1950s, the first computer-assisted drawing software came into being when an MIT scientist named Douglas T. Ross was inspired by the digital graphics on radar displays to create what became known as computer-aided design software, or CAD. CAD first took off in the automotive industry, but it quickly became clear that it had a place in architects’ offices as well. And while the early simple software was useful for drawing up blueprints, it’s allowed for increasingly sophisticated modeling, the kind that’s essential for designing modern, high-tech skyscrapers.

Scott Johnson: Structural design was really one of the first things where we use computers to track changes and stresses in, say, a steel frame and a tall building. And then in some cases, in our case, we applied computers to actually the formal development of architecture in aesthetics.

Walter Isaacson: Scott Johnson is a design partner and founder at the Los Angeles architectural firm Johnson Fain.

Scott Johnson: It was maybe three decades ago, and the architect figured out what he or she wanted to do, and once we figured that out, we sent it around to the engineers and specialty consultants and they applied their overlay on it. We went back and forth until we had a completed design. Today from day one when you begin a design process, you share software, usually three-dimensional software. Well, it’s algorithmic, so in theory you can develop formal languages for architecture in any way you want. A building does not have to be a rectangle. It doesn’t have to have a flat skin. It can be anything that you choose it will be.

Walter Isaacson: But beyond just the rippling, wave-shaped walls of steel and glass that can be created with computer-assisted design, the software also allows the construction of far more energy efficient and sustainable skyscrapers. Johnson calls these new types of buildings a formative.

Scott Johnson: You could be designing the skin of a tall building and you could measure as you design it how much solar radiation it would absorb, a lot or a little, affecting how much energy would be required to air condition and expel the heat or not. Most major buildings are trying to achieve higher levels of performance in terms of reducing the amount of energy they use, the amount of carbon they require. And now every little nuance in the design, you can now measure it as you’re designing in real time to diminish the amount of energy consumption, which on the whole is about 50% of the entire energy we use in the United States is used in the performance of buildings. So if we can take a meaningful hit on that, we can significantly reduce our appetite for energy.

Walter Isaacson: Some engineers are actually using skyscrapers’ impressive height to find novel ways to decrease its environmental impact. Bill Baker.

Bill Baker: I remember going up on the outside of the Burj Khalifa during construction, and it was July, and so you’re right on the Gulf, so it’s pretty hot, pretty humid, and then going up. And we’d go up on the outside in these man hoists, and around level 50, all of a sudden you started to notice, and then when we got up to level 160, it was pleasant. The temperature had dropped quite a bit. The humidity had dropped, the air had less dust in it, and it was really quite remarkable. And so sustainable engineers called it sky source sustainability, where they would actually try to pull in the fresher, cooler air from up high and use it for the operations of the buildings.

Bill Baker: And I think people will get more and more clever about that: as these buildings have a lot of surface area, can we use that to generate electricity? But certainly the operations, the internal energy use, is going way down with better lighting systems and better heating and cooling systems. There’s huge efficiencies starting to be realized there. And so can the outside of the building, through its height, we are grabbing … Perhaps you’ve heard of geothermal, maybe this is sky thermal, okay?

Walter Isaacson: Ultimately, tall buildings’ largest environmental impact may be in the way they draw people to live closer to each other and share resources. The closer together we live, the less fossil fuel we’ll need to burn to get around, and the more efficient the systems that keep us comfortable can be. Scott Johnson.

Scott Johnson: Sustainability is a very complex phenomenon, and to be meaningful, it really has to be discussed in its complexity. The amount of what we call embedded energy in a tall, high-rise building is probably greater than in a log cabin, meaning the amount of energy it takes to produce a highly specialized, very tall, let’s call it very heavy, building, is probably greater than a two-story log cabin. However, having said that, if you were in a city with a lot of tall buildings, your occupancy density would be higher. There would be more people living within walkable distances to the things they need. And in terms of a comprehensive understanding of sustainability, people would in theory be walking or taking public transit, and the transit cost or transportation costs, the use of energy, would be significantly less. So you have to look at sustainability in three dimension, really.

Walter Isaacson: Carol Willis calls this phenomenon vertical density, and she believes that, properly managed, it’s not only sustainable, but can increase a city dweller’s quality of life.

Carol Willis: It’s a virtuous circle, so long as the necessary companions of open space, which is public and available to all, and mass transit, which removes cars from the road and makes people’s lives better and the environment better.

Walter Isaacson: In 2018, the United Nations released a study predicting that by 2050, nearly 70% of the world’s population will live in urban areas, an increase from today’s 55%. While skyscrapers have long been symbols of wealth and ego, as we cluster together more tightly in cities, they may be our only option to survive the growth of big cities and the environmental impact of our growing global population. Ever since the legend of the Tower of Babel, humans have dreamed of reaching the heavens in manmade towers. Now we may find that our very survival as a species does in fact lie up there in the clouds.

Walter Isaacson: I’m Walter Isaacson, and you’ve been listening to Trailblazers, an original podcast from Dell Technologies. If you want to read more about any of the guests featured on today’s show, you can head to our website at Thanks for listening.