Think for a moment about the world's tallest buildings.
For many, one that comes to mind is New York City's Empire State Building. The Empire State Building became the world's tallest building once it wrapped up construction in 1931. It also became one of America's most iconic structures in subsequent decades. However, few thought anything would surpass the Empire State Building.
The idea of building taller structures seemed dangerous and inefficient. Without one man's innovation, incredible structures like the Burj Kalifa and other notable skyscrapers might not exist as we know them today.
Engineer Fazlur Rahman Khan is to thank for the new generation of skyscrapers creating stunning focal points in hundreds of city skylines.
Fazlur Rahman Khan's High-Rise to Success
Born in 1929, Khan grew up in Dacca, India or what is now called Dhaka, Bangladesh. He earned a Bachelor's Degree in Engineering from the University of Dacca in 1950. Shortly after his graduation, Khan went to work as an assistant engineer for the India Highway Department.
He earned a scholarship to travel to the United States in 1952 and study at the University of Illinois in Chicago. That city would see some of Khan's greatest innovations; two of his most famous buildings have become Chicago staples.
During his time at the University of Illinois, Khan earned two Master's Degrees, one in Applied Mechanics and the other in Structural Engineering. He continued on to earn his Ph.D. in Structural Engineering as well.
He left the U.S. for a short time to go to Pakistan. He'd earned a job as the executive engineer for the prestigious Karachi Development Authority. However, he became frustrated by restrictions with the position, and he wanted more time to design.
He returned to the U.S. in 1955 and joined Skidmore, Owings & Merrill in Chicago.
Building His Innovation
While at Skidmore, Owings & Merrill, Khan had a breakthrough.
He created a building not held up by central supports of steel but by an exterior frame. The vertical tubing would protect against structural damage from high winds while freeing up room in the building's interior normally used for central supports.
In the 'Windy City' of Chicago, structural integrity seems even more crucial than other major cities like New York. Probably more difficult than the city's chilly breezes, however, is its swampy foundation. While New York City boasts bedrock to build upon, Chicago projects were often 'doomed' to fail because of the inconsistent ground.
"It became a proven new structural concept waiting to be tested on a real building," Khan once said. "John Hancock Center offered that opportunity."
Khan tested his theory on the DeWitt-Chestnut building in Chicago. While it didn't surpass the Empire State Building in height, it won in terms of efficiency. The building used 145kg of steel per square meter, significantly less than the Empire State Building's 206kg per square meter.
Khan then designed the World Trade Center, a building that finally broke the record as the world's tallest building, when it opened in 1972.
Two years later, another Khan design took the title. Chicago's Sears Tower served as the world's tallest building for 24 years.
The Sears Tower (now the Willis Tower) became the first skyscraper to use the bundled tube system, which clusters narrow cylinders to form a thicker column. It both minimized steel usage and removed the need for internal wind braces.
Remembering His Legacy
Khan died in 1982, and he left behind an international legacy of innovation and engineering brilliance. He's often referred to as the "Einstein of Structural Engineering". The title is incredibly impressive given that the man never saw a skyscraper until he was 21 years old.
Mark Sarkisian, director of Structural and Seismic Engineering at SOM said, "Khan was a visionary who transformed skyscrapers into sky cities while staying firmly grounded in the fundamentals of engineering."
His tube structures can be seen in many of the skyscrapers found atop lists of the world's tallest. This is due, in part, to what Khan called "structural empathy," or the idea that buildings should act like the human body and absorb stresses in a more natural way.
"I put myself in the place of a whole building, feeling every part," Khan said. "In my mind, I visualize the stresses and twisting a building undergoes."
Mentalfloss's Nick Greene explained it further: "If someone pushes you in the chest, your ribs alone don't prevent you from falling-- your stomach clenches, your calves brace, and your heels dig into the ground. The pieces work in tandem. The same went for skyscrapers."
Not only was he a structural genius; Khan championed the usage of computer-aided designs for precise calculations. He brought on two young computer programmers to verify his calculations on the John Hancock Center.
— Chicago Architecture (@chiarchitecture) April 3, 2017
Plenty of Chicago-area groups are posting their gratitude to one of the most influential architects of the modern era:
— ChicagoHistoryMuseum (@ChicagoMuseum) February 17, 2017
Wise Words from Khan
Khan, a man that could have been so engrossed in his own work, never lost sight of what was important -- the people found within the structures he built. He offered humanitarian assistance during Bangladesh's war of independence. His daughter Yasmin Sabina Khan noted that "He was inspired by the belief that his work had a positive impact and he encouraged other engineers not to lose track of the purpose of their profession."
And what was that purpose? Khan explained it beautifully after being named Construction's Man of the Year in 1972:
"The technical man must not be lost in his own technology; he must be able to appreciate life, and life is art, drama, music, and most importantly, people."