Look up at a modern skyscraper.The higher the building rises, the more extraordinary it seems. Hundreds of metres above the ground, thousands of tonnes of steel and concrete are exposed to something that cannot be seen: wind. For centuries, people learned how to build wider, stronger and more massive structures. But the skyscraper created a different problem. The taller a building became, the more important it was to control the forces pushing against it from the side. A structure could be strong enough to carry its own weight and still face enormous engineering challenges from wind.By the middle of the twentieth century, engineers were searching for better answers.One of the people who transformed that search was a young engineer born in Dhaka in 1929.
His name was Fazlur Rahman Khan. He would eventually become one of the most influential structural engineers of the twentieth century—a man whose ideas helped make the modern skyscraper economically and structurally practical. His work helped shape Chicago’s John Hancock Center and Sears Tower, now known as Willis Tower, and his structural concepts continue to influence tall-building design decades after his death. The Council on Tall Buildings and Urban Habitat later described Khan as one of the engineers whose work helped redefine the skyscraper.
But Khan’s story is much bigger than two famous towers.
He was a mathematician who loved practical problems, an engineer fascinated by architecture, an early advocate of using computers in structural design, a Bangladeshi who became an American citizen, and an internationally respected professional who remained deeply connected to his homeland.During Bangladesh’s Liberation War in 1971, he also used his position and network in the United States to support the cause of Bangladesh.
His life therefore tells several stories at once:
the story of a boy from Bengal, the story of an immigrant engineer, the story of a technological revolution, and the story of a Bangladeshi whose ideas reached the world’s tallest buildings.
1. A Boy from Dhaka
Fazlur Rahman Khan was born on 3 April 1929 in Dhaka, then part of British India. Today, the city is the capital of Bangladesh.Although he was born in Dhaka, his family had roots in Bhandarikandi, in present-day Shibchar of Madaripur. His father, Khan Bahadur Abdur Rahman Khan, was an educationist and senior government education official. He had begun his career as a mathematics teacher and textbook writer and eventually served as Bengal’s Director of Public Instruction. After retiring from government service, he became the first principal of Jagannath College in Dhaka.That background mattered.
Fazlur Rahman Khan did not grow up in a family where education was simply encouraged; he grew up around a father whose professional life was deeply connected with teaching, mathematics and education.The young Fazlur was particularly comfortable with mathematics and practical problems. Later recollections of his life describe him as someone who enjoyed understanding how things worked rather than merely memorising formulas.That combination would eventually become one of his greatest strengths.He could think like a mathematician.But he wanted his mathematics to do something in the real world.That distinction would become crucial.
2. From Bengal to Engineering
Khan’s education took place during a period when the Indian subcontinent itself was changing rapidly.He attended school in Dhaka and eventually pursued civil engineering. Sources differ somewhat in their descriptions of the exact sequence of his early education, but they agree on the central fact: he emerged as an exceptionally talented civil engineering student and completed his bachelor’s degree at Ahsanullah Engineering College, the institution that later became part of today’s Bangladesh University of Engineering and Technology (BUET).
At Ahsanullah Engineering College, he stood out academically.He completed his Bachelor of Civil Engineering degree in 1950, graduating with outstanding results. BUET’s Department of Civil Engineering records that he later served as a lecturer at the institution before leaving for the United States for advanced study.There was, however, an important turning point ahead.Khan had already demonstrated that he could excel academically in South Asia. The next question was what he would do with that ability.The answer came in the form of scholarships.
3. Three Degrees in Three Years
In 1952, Fazlur Rahman Khan travelled to the United States for graduate study at the University of Illinois at Urbana-Champaign.He had received scholarship support that included a Fulbright scholarship and government assistance.What happened next was extraordinary.
In only three years, Khan earned:
- a master’s degree in Structural Engineering;
- a master’s degree in Theoretical and Applied Mechanics; and
- a PhD in Structural Engineering.
The University of Illinois records his degrees as an MS in Structural Engineering in 1952, an MS in Theoretical and Applied Mechanics in 1955, and a PhD in Structural Engineering in 1955.His doctoral research was highly technical, focusing on relationships among different design criteria for rectangular prestressed-concrete beams.To a general reader, that subject might sound far removed from skyscrapers.In retrospect, however, it reveals something important about Khan’s approach to engineering.
He was interested in finding relationships between theory, materials, forces and efficient design.That habit of looking for the underlying system would later become the foundation of his skyscraper revolution.And there was another thing happening.America was about to become the place where Khan would turn his mathematical and engineering ability into ideas that would change the world’s cities.
4. Chicago: The City That Changed His Life
After completing his doctorate, Khan joined the Chicago-based architectural and engineering firm Skidmore, Owings & Merrill (SOM) in 1955.Chicago was an extraordinary place for an engineer interested in tall buildings.The city had helped give birth to the skyscraper in the late nineteenth century. By the middle of the twentieth century, however, building ever higher was no longer simply a matter of adding more floors.The engineering problem was becoming increasingly severe.A tall building must carry its own weight.
But as it grows taller, wind becomes a dominant structural problem.Imagine holding a thin ruler upright.Push it gently from the side. Now imagine making that ruler hundreds of metres tall.The taller it becomes, the more important its ability to resist sideways movement becomes.That was the problem Khan wanted to solve.And he approached it differently from many engineers before him.Instead of thinking primarily about a skyscraper as a collection of vertical columns supporting floors, Khan began thinking about the building’s entire outer structure as a kind of tube.This simple conceptual shift would change skyscraper engineering.
5. The Idea That Changed the Skyscraper
Before Khan’s innovations, very tall buildings often depended heavily on large internal structural frames. As buildings became taller, however, increasingly large amounts of structural material could be required simply to resist lateral forces. That could make very tall buildings expensive and inefficient. Khan’s insight was that the exterior of a building could participate much more actively in resisting those forces. The building could behave structurally more like a tube. The idea sounds simple today. It was revolutionary at the time.
Khan developed a family of structural systems that became known collectively with the term tubular structures. These included the framed tube, trussed tube and bundled tube systems. His innovations allowed engineers and architects to construct taller buildings with greater structural efficiency and more usable interior space. BUET describes the tubular structural system he developed in the 1960s as a breakthrough that made super-tall buildings more feasible and economical. This is why Khan is so often remembered as the “father of tubular designs.”
But the phrase can obscure just how radical his contribution was. He did not simply invent one formula. He developed a way of thinking about tall buildings. Different heights and different building types required different structural systems. Khan’s work helped establish the idea that engineers should select the most efficient structural system according to the building’s height and requirements. A later CTBUH analysis describes this systems-based approach as one of his greatest contributions to twentieth-century high-rise technology.
In other words, Khan was not asking only:
“How can we make this building stand?”
He was asking:
“What is the smartest structural system for this building?”
That question changed everything.
6. Dewitt-Chestnut: The Experiment Before the Revolution
One of the important steps in Khan’s development of tubular design came before his most famous towers. For the DeWitt-Chestnut apartment building in Chicago, Khan developed a structural system in which closely spaced columns around the building’s perimeter worked together like a thin-walled tube. The result was significant. The exterior structure could take much of the wind-related loading, allowing greater freedom inside the building. SOM describes the project as an important precursor to the system later used at the John Hancock Center. Khan had found a way to make the skin of a skyscraper part of its strength.
7. The Building with the Giant X
In Chicago, a new tower was being conceived that would eventually become one of the most recognizable skyscrapers in the world. It is now known as 875 North Michigan Avenue. For decades, however, most people knew it as the John Hancock Center. The building was the product of a remarkable partnership between architect Bruce Graham and structural engineer Fazlur Rahman Khan at SOM. SOM describes their collaboration as a defining example of the integration of architecture and structural engineering.
The project posed an unusual challenge. The developers wanted multiple functions in a single tower: offices, apartments, shops and other uses. One proposal involved separate towers for different functions. But that would consume too much of the available site and create problems involving privacy and daylight. The solution was to combine the functions in one very tall building. Khan’s structural idea made that possible. Instead of hiding the structural system inside the building, he and Graham allowed the structure to become part of the building’s visual identity. The tower’s famous diagonal braces form enormous X-shaped patterns across its dark exterior. Those X’s are not decoration.
They are structure.
The diagonal bracing forms a highly efficient external trussed tube, allowing the building to resist lateral forces while using structural material efficiently. SOM identifies the building as the first major application of its exterior diagonalized tube system. The tower reached an architectural height of approximately 1,128 feet (344 metres) and was completed in 1970.
The result was something rare in architecture:
Engineering became architecture.
The structure that made the building possible also became the thing that made the building beautiful. That was one of Khan’s great gifts. He did not believe engineering had to be hidden.
8. Then Came the Tower That Changed the World
The John Hancock Center demonstrated what Khan’s ideas could do. But his most famous structural breakthrough was still ahead. Chicago’s Sears, Roebuck & Co. wanted a headquarters large enough to bring together thousands of employees. The project would become the Sears Tower, now known as Willis Tower. And it would be enormous. At 1,450 feet (442 metres), the tower would become the world’s tallest building when completed in 1973. It remained the world’s tallest building until 1998. But how could anyone make such a huge building structurally efficient?
Khan’s answer was one of his most famous innovations:
The bundled tube.
Imagine several strong square tubes standing side by side. Now imagine connecting them into a single structural system. Instead of treating the skyscraper as one enormous slender frame, the building could behave as a group of interconnected tubes working together. That was the basic concept behind the Sears Tower’s structural system. SOM describes the tower as nine separate structural tubes that rise together and then step back at different heights, creating its distinctive form. The idea had another important advantage. The shape of the structure itself became the architecture. The building did not need an elaborate decorative skin to tell people how it worked. You could look at the tower and see the engineering. That was Khan’s philosophy at its most powerful.
9. He Was Not Just Designing Buildings—He Was Changing the Rules
It would be easy to look at the John Hancock Center and Willis Tower and conclude that Khan was simply an exceptionally talented engineer who helped design two famous skyscrapers. That would underestimate him. His real contribution was a new structural vocabulary for tall buildings. The tubular concept could be adapted. Different variations could be used depending on the building’s height, materials and function. The approach reduced the amount of structural material required compared with less efficient systems while maintaining the stiffness necessary for very tall buildings. The impact was enormous.
Modern skyscraper engineering would continue to develop beyond Khan’s specific systems, but his ideas became part of the foundation upon which later generations of supertall buildings were developed. SOM itself notes that Khan’s tube systems remain fundamental to modern supertall structural engineering. His influence therefore reaches far beyond Chicago. It reaches upward.
10. The Engineer Who Embraced Computers Before They Were Everywhere
There is another part of Khan’s story that deserves much more attention. He was not only innovating in structural engineering. He was also interested in computers. In the early 1960s, computers were nothing like the laptops and smartphones people know today. They were expensive, enormous machines that could seem like an extraordinary investment for an architecture and engineering firm. Khan encouraged SOM to embrace computer technology for structural analysis and design.
SOM records that, at Khan’s urging, the firm installed an IBM 1620 in 1963 and began exploring the use of computers in structural design. This was remarkably forward-looking. The engineer who was changing the physical structure of skyscrapers was also helping change the way engineers thought about and calculated those structures. That combination—structural intuition, mathematics and emerging computing technology—gave Khan an unusual advantage. He could imagine a structural system conceptually and increasingly use computers to explore and analyse it. The skyscraper was becoming not just a physical object. It was becoming a system that could be modelled, calculated and optimized.
11. Beyond the Skyscraper
Despite becoming famous for tall buildings, Khan did not limit himself to skyscrapers. His work extended into several different kinds of structures. One of the most remarkable was the Hajj Terminal at King Abdulaziz International Airport in Jeddah, Saudi Arabia.
The terminal was completed in 1981 and was designed by SOM with Fazlur Rahman Khan. The project used enormous fabric structures suspended from steel pylons, creating a roof inspired by tent forms associated with the region. The Aga Khan Trust for Culture lists Khan/SOM as the architect for the award-winning project.
The Hajj Terminal presented a completely different structural challenge from the John Hancock Center or Sears Tower. There was no need to build upward. Instead, the challenge was to create vast areas of shelter while maintaining openness and responding to the needs of millions of pilgrims passing through the airport. The result demonstrated another side of Khan’s imagination. He could work with steel and concrete. But he could also work with fabric, tension and space.
The project later received the Aga Khan Award for Architecture, and its structural and architectural qualities became internationally recognized. Khan’s career therefore cannot accurately be reduced to one sentence such as “the engineer who designed the Sears Tower.” He was a structural innovator whose work ranged from supertall towers to large-span structures and other specialized buildings. The Institution of Engineers, Bangladesh notes his work on projects including the Hajj Terminal, McMath-Pierce Solar Telescope and stadium structures.
12. The Bangladeshi Behind the American Skyline
There is something deeply striking about Khan’s biography. He was working in Chicago, helping shape buildings that would become symbols of American economic power and technological ambition. Yet his story began in Bengal. The world would come to know him as an American engineer. Bangladesh would remember him as one of its greatest sons. Both descriptions are true. Khan became a United States citizen in 1967, but he never simply erased the place from which he came. His professional identity became international. His personal story remained rooted in South Asia. And in 1971, that connection became especially important.
13. When Bangladesh Needed a Voice
When the Liberation War began in 1971, Bangladesh was thousands of kilometres away from Chicago. Khan, however, was not a passive observer. He became involved in efforts to mobilize support among Bangladeshis living in the United States and to generate support for the independence struggle. Sources from the Institution of Engineers, Bangladesh and other biographical accounts describe his efforts during the Liberation War, including mobilizing support among Bangladeshis in the United States.
This chapter of his life deserves special attention because it reveals something that the photographs of skyscrapers cannot show. The man who spent his professional life thinking about structures was also thinking about a nation. He had achieved extraordinary professional success in America. But when the country of his birth was fighting for independence, his expertise, reputation and network became tools he could use in another kind of struggle. His story was no longer only about steel and concrete. It was about belonging.
14. The Human Being Behind the Engineering
Khan’s professional achievements can make him seem almost larger than life. But people who knew him remembered something more human. He had the rare ability to discuss complicated engineering concepts in language that ordinary people could understand. A retrospective study of his life and work noted his ability to explain intricate structural problems simply, even to people without technical backgrounds. That quality is important. Great innovators are not necessarily the people who know the most complicated equations. Sometimes they are the people who can take a complicated problem and see its simplest underlying idea. Khan’s tubular structures were mathematically sophisticated. But the underlying intuition could be expressed simply: Make the whole building work together. That idea changed the skyline.
15. A Career That Ended Too Soon
By the late 1970s and early 1980s, Khan had become one of the most respected structural engineers in the world. He had risen through the ranks at SOM, becoming a full partner in 1970. The University of Illinois records his professional progression and describes his work as involving innovative structural systems for steel and concrete high-rise buildings. He also served as chairman of the Council on Tall Buildings and Urban Habitat from 1979 to 1982. But his career was cut tragically short. On 27 March 1982, just seven days before his 53rd birthday, Fazlur Rahman Khan died in Jeddah, Saudi Arabia, during a business trip in the Middle East. The National Academy of Engineering memorial described his sudden death as a major loss to the field of tall-building engineering.
He was only 52 years old. He had spent less than three decades in professional practice. Yet in that relatively short period, he had helped change one of the most technically demanding areas of modern construction. His buildings would continue to rise. His ideas would continue to spread. And his influence would outlive him by generations.
16. Why the World Still Remembers Fazlur Rahman Khan
The easiest way to understand Khan’s legacy is to look at the modern city. Skyscrapers today are everywhere. They rise in Dubai, Shanghai, Singapore, Kuala Lumpur, New York, Seoul, Hong Kong and dozens of other cities. Their structural systems have continued to evolve.
But the central question remains the same:
How do you make a very tall building strong, efficient, economical and usable?
Fazlur Rahman Khan helped change the answer. His innovations showed that the structure of a tall building could be integrated with its architecture rather than treated as something separate and hidden. His work demonstrated that structural efficiency could make extreme height more economically practical. And his systems became part of the technological foundation of the modern supertall. That is why SOM describes him as an engineer whose influence extended far beyond the individual buildings he worked on. His legacy is not simply a tower in Chicago.
It is an entire way of thinking.
17. A Name That Became Part of Chicago
Khan’s adopted city did not forget him. A sculpture honoring him was installed in the lobby of the Sears Tower, now Willis Tower. And in 1998, the City of Chicago named the intersection of Jackson and Franklin Streets, near the foot of the tower, “Fazlur R. Khan Way.” There is something poetic about that. At one end of his story stands a young boy from Dhaka. At the other stands one of the world’s great cities, giving a street corner the name of the engineer who helped change its skyline.
18. More Than the “Father of Tubular Designs”
The title “Father of Tubular Designs” is deserved. But it is not enough. Fazlur Rahman Khan was: a structural engineer who transformed skyscraper design; an innovator who embraced computer technology early; a collaborator who understood that engineering and architecture could reinforce each other; an educator and thinker who could make difficult ideas understandable; a Bangladeshi who became an important American professional; and a man who used his international position to support Bangladesh during its Liberation War. His greatest achievement may therefore not be any single building. It may be the fact that he changed the question engineers asked. Before Khan, the question was increasingly:
“How can we build this tall?”
After Khan, it became:
“What is the most efficient structural system for building this tall?”
That is a much more powerful question. And sometimes, changing the question is how you change the world.
Fazlur Rahman Khan — Quick Facts
| Fact | Detail |
| Full name | Fazlur Rahman Khan |
| Born | 3 April 1929 |
| Birthplace | Dhaka, British India |
| Family roots | Bhandarikandi, present-day Shibchar, Madaripur |
| Profession | Structural Engineer; Architect |
| Higher education | University of Illinois at Urbana-Champaign |
| Major employer | Skidmore, Owings & Merrill (SOM) |
| Famous structural innovations | Framed tube, trussed tube, bundled tube |
| Most famous buildings | John Hancock Center; Sears Tower/Willis Tower |
| Major non-skyscraper work | Hajj Terminal, Jeddah |
| U.S. citizenship | 1967 |
| CTBUH leadership | Chairman, 1979–1982 |
| Died | 27 March 1982 |
| Age at death | 52 |
| Major posthumous legacy | Fazlur Khan Lifetime Achievement Medal, Chicago’s Fazlur R. Khan Way |
The Story Is Not Over
The buildings are perhaps the easiest part of Fazlur Rahman Khan’s story to see. The harder—and more fascinating—part lies underneath them.
Why did he think differently?
How exactly did he develop the tubular concept? What happened inside the SOM offices when Khan and Bruce Graham began experimenting with the John Hancock Center? How did the Sears Tower’s bundled-tube idea emerge? Why did Khan believe architecture and engineering should not be separated? What was his relationship with Bangladesh after moving to America? What exactly did he do during the 1971 Liberation War? What did his colleagues say about him? What did he believe about the future of cities? And how did the ideas of a Bangladeshi engineer eventually influence skyscrapers that would rise decades after his death? Those questions take us beyond the famous photographs. And that is where the real story of Fazlur Rahman Khan begins.
19. The Man Behind the Mathematics
A photograph of Fazlur Rahman Khan can be slightly misleading. In many of the surviving photographs, he appears beside a model of a skyscraper, surrounded by architects and engineers, or seated behind a desk covered with drawings. It is easy to see only the engineer. But people who knew him remembered a much broader personality. Khan was deeply interested in music, literature, philosophy and the arts. He loved classical music, particularly Bach and Brahms, and enjoyed singing Rabindranath Tagore’s songs in Bengali with family and friends. Later tributes described him not simply as a structural engineer but as a philosopher, visionary, educator and humanist.
That combination helps explain something important about his professional work. Khan did not see a building as merely a machine for carrying loads. He believed that engineering could contribute to beauty. A structural system could be efficient and elegant at the same time. A column, a brace or a structural tube did not necessarily have to disappear behind an architectural façade. It could become part of the architecture itself. That philosophy became particularly visible in the John Hancock Center.
20. The Partnership That Changed Chicago
The story of Fazlur Rahman Khan cannot be told properly without Bruce Graham. Graham was an architect. Khan was a structural engineer. Their partnership at Skidmore, Owings & Merrill became one of the most important architect-engineer collaborations in twentieth-century American architecture. They were different kinds of thinkers. Graham was concerned with architectural form, space, urban presence and how people experienced a building. Khan was concerned with forces, materials, structural efficiency and the invisible mathematics that allowed the building to stand. But instead of treating those concerns as separate, they worked together. That collaboration was especially important because SOM operated differently from many conventional architecture practices. Architects and engineers worked within the same organization, allowing structural ideas to influence architectural design from the beginning.
The John Hancock Center became the great demonstration of what could happen when the two disciplines were genuinely integrated. Princeton University’s study of the project notes that the design team was led by Graham and Khan and initially included roughly 60 architects and engineers. This was not simply an architect handing a finished design to an engineer and asking:
“Can you make this stand?”
The structure was part of the design from the beginning.
21. The Problem That Nearly Killed the Idea
The John Hancock project presented a brutal engineering challenge. The developers wanted a huge mixed-use building containing offices and residences. The amount of floor space required was enormous. An early proposal considered separate towers: one for offices and another for apartments. But the project had a major problem. The site was constrained, and the economic realities of the development made a conventional approach difficult. More importantly, the height being considered created structural demands that traditional systems could not satisfy economically. Princeton’s research into the project records that the initial structural analysis showed that the required height would be economically unfeasible using conventional structural solutions. This was precisely the kind of problem Khan loved. Instead of asking how to make the conventional system stronger, he asked whether the building should use a completely different structural system. The answer became the trussed tube.
22. Why the Giant X’s Matter
Walk along Michigan Avenue in Chicago and look up at the tower. The first thing many people notice is the giant black X-pattern running across its exterior. For someone unfamiliar with engineering, those X’s might look like a stylistic decision. They are not. They are the building’s structural logic made visible. The diagonal braces connect the exterior structural frame so that the entire building can act much more effectively against lateral forces. Instead of asking the interior columns to do all the work, Khan moved much of the structural action toward the perimeter.
The result was a kind of structural tube strengthened with diagonal bracing. This became known as the trussed tube. The building was completed in 1969/1970, and its 100-story form became one of the most recognizable silhouettes in Chicago. Khan had achieved something more important than making a tall building stand. He had made the building’s strength visible.
23. A New Way of Thinking About Materials
There was another reason Khan’s work mattered. Tall buildings require enormous quantities of structural material. If an engineer simply adds more steel whenever a building becomes taller, the structure can eventually become so heavy and expensive that the project stops making economic sense. Khan’s approach was different. He wanted to understand where the material was actually needed. Then he wanted the structure to put that material to work as efficiently as possible. This was an engineer’s version of a simple principle:
Don’t make the structure stronger everywhere. Make it stronger where the forces demand it.
The tubular system allowed a building’s perimeter to become a major part of its lateral-force-resisting structure. The result was more structural efficiency. That efficiency was one of the reasons the modern skyscraper could become economically viable at heights that had previously been extraordinarily difficult to achieve. The National Academy of Engineering’s memorial described Khan’s bundled-tube system as a way of reducing the structural steel or concrete required for very large towers and thereby making them economically feasible. That is perhaps the best way to understand the scale of his contribution. Khan did not merely help buildings become taller. He helped make height economical.
24. Sears Tower: When the Tube Became a Bundle
If the John Hancock Center demonstrated the power of the trussed tube, the Sears Tower demonstrated what happened when Khan pushed the tubular concept further. The problem was now extraordinary. Sears, Roebuck & Co. wanted a headquarters that would contain an enormous amount of office space. The tower would need to be taller than anything previously built. The answer was not one giant tube. It was a collection of tubes working together. Khan developed the bundled tube concept. Imagine nine vertical structural tubes arranged together.
Each tube could behave structurally, but the tubes could also work together as one enormous system. This allowed the tower to achieve enormous height without requiring the same structural inefficiency that a conventional frame would have created.
The National Academy of Engineering described the bundled tube as Khan’s signature innovation and noted that it was first used in the Sears Tower. The tower’s architecture made the concept visible. Instead of rising as one perfectly uniform shaft, the building’s tubes terminate at different heights. That creates the familiar stepped profile of the tower. Once again, the structural system generated the architecture.
25. The Tallest Building in the World
When the Sears Tower was completed, it stood approximately 1,450 feet (442 metres) tall. For a time, it was the tallest building in the world. That distinction lasted for roughly a quarter of a century, until the Petronas Towers in Kuala Lumpur surpassed it in height in the late 1990s. But the numerical record is not the most important part of the story. The more important question is:
Why could such a tower exist at all?
The answer lies in the structural system. The Sears Tower showed the world that a building could be extraordinarily tall without simply becoming an enormous pile of structural material. It could be tall and efficient. That was the breakthrough.
26. Khan Was Already Thinking About the Future
Khan’s thinking was not limited to the buildings immediately in front of him. He was interested in what would happen to cities as populations grew. If millions more people were going to live and work in cities, urban land would become increasingly valuable. Building upward could become one solution. But simply building taller was not enough.
Tall buildings had to be:
- structurally efficient,
- economically practical,
- adaptable,
- architecturally meaningful,
- and comfortable for people.
Khan therefore viewed structural engineering as part of a larger urban problem. The skyscraper was not an isolated object. It was part of the future of the city. That is one reason his influence extended beyond individual projects.
27. The Engineer Who Became a Mentor
Khan’s influence was not transmitted only through buildings. It was also transmitted through people. His colleagues remembered him as someone who encouraged younger engineers and gave them responsibility.
The Oxford Research Encyclopedia’s biographical treatment of Khan specifically identifies “Fazlur Khan as a Colleague and a Collaborative Team Builder” and “Dr. Fazlur Khan as a Mentor” as important aspects of his career.
That is significant. A great engineer can leave behind a building. A great mentor can leave behind an entire generation. Khan helped create an environment in which structural engineers could think creatively rather than simply execute calculations handed down by others. He wanted engineers to participate in architectural thinking. That attitude helped elevate structural engineering from a supporting technical discipline into an important part of architectural creativity.
28. He Did Not Believe Engineers Should Hide
There was an old tendency in architecture to think of structure as something that should disappear. The architect created the visible building. The engineer made sure it did not collapse. Khan challenged that separation. His buildings suggested another possibility:
What if the structure itself became architecture?
The diagonal braces of the John Hancock Center are the obvious example. The bundled form of Sears Tower is another. In both cases, the structural system is inseparable from the visual identity of the building. This was not structural engineering competing with architecture. It was structural engineering creating architecture.
29. The Computer in the Office
Khan’s willingness to embrace technology was another indication of how far ahead he was thinking. In 1963, SOM installed an IBM 1620 after Khan encouraged the firm to explore computer-based structural analysis and design. Today, engineers routinely use sophisticated software to model enormous buildings. But in the early 1960s, this was still a relatively new idea.
Khan understood that computers could allow engineers to analyse increasingly complicated structures more efficiently. This did not replace engineering intuition. It enhanced it. His approach combined three things: physical intuition + mathematical understanding + computational analysis. That combination became increasingly important as buildings grew more complex. In this sense, Khan was not merely an innovator in structural systems. He was also an early participant in the digital transformation of engineering.