By Kathy Krepps, Class of 2017, and Bobbi Pinkert, Class of 1999
All photographs from SOM unless noted
If the architect outlines the story of a building, it’s the engineers who bring the story to life. In the pantheon of engineers, one name stands above all the rest: Fazlur Kahn. This Einstein of Structural Engineering, along with architect and collaborator Bruce Graham, was responsible for some of the most iconic buildings in Chicago. How fitting, then, that the Council on Tall Buildings and Urban Design (CTBUH) commemorates their symbiotic relationship by awarding an annual Fazlur R. Khan Lifetime Award recognizing excellence in technical design, innovations, and breakthroughs in engineering systems.
The 2024 award winner, John Zils, joins two previous winners from the Chicago SOM office, Srinivasa ‘Hal’ Iyengar in 2006 and William F. Baker in 2008. It is no coincidence that each of these acclaimed engineers worked with the legendary namesake of this award, Fazlur Rahman Khan, who spawned a new generation of engineers, taking the practice to new heights, both aesthetically and structurally.
Witness John Zils, who will receive the 2024 Fazlur Kahn Lifetime Achievement Award this September at the CTBUH annual conference. Zils rejoined SOM in 1969 after a stint in the army and took over as the Sears Tower project engineer under Fazlur Kahn. There he learned the importance of “fostering an integrated process of work between architects and structural engineers” (Mas Context) that became the firm’s governing philosophy. For Zils, it was always about the art of the simple: how do you get 76,000 tons of steel to its exact location; how do you build a flower; and how do you curve a trellis?
While Kahn figured out how to use one half the proposed steel at Sears, Zils figured out how to get it in place without it having it touch the ground. This was accomplished by positioning cranes on the four sides of the building and lifting the steel directly into place from the delivery trucks.
In 1992, Frank Gehry designed a fish sculpture for the Barcelona Olympic Games and SOM built it. Which brought Gehry to ask Zils, “Now that you’ve done a fish, would you like to do a flower?” (Mas Context). The flower bloomed into the Guggenheim Museum in Bilbao, Spain. Zils’ influence in using steel rather than reinforced concrete, and thinking of the structure as a ship rather than a building, brought the structure to flawless fruition.
The art of the simple for Zils means integrating the work of architect and engineer with, “a design that is not only responsive to the architecture, but have a practical sense to them, that can be built and fabricated easily”. (ff Journal) He advocated adding the supplier into early design works. For Gehry’s Pritzker Pavilion trellis, Zils and the steel fabricator changed curving the pipe in two planes to curving it in one plane and reducing the number of joints, resulting in a simple solution that saved time and money.
Next, consider the brilliant achievements of 2006 award winner Hal Iyengar’s five-decade career at SOM. For Iyengar, it was all about structure. He describes flourishing under SOM’s collaborative approach to design which comes, “from the Miesian tradition that structure is important, and it forms the backbone and is the essence of architecture.” (Blum, 2008). Iyengar was Khan’s right-hand man as Khan and architect Bruce Graham developed the innovative framing structures for the X-braced John Hancock Center (now 875 N. Michigan Ave.) and for the Sears (now Willis) Tower (Kamin, 2019).
In the early 60’s, Iyengar partnered with Khan to introduce computers to SOM’s structural design. Using the early program-oriented language Fortran, they worked “day and night” (Blum, 2008) to write their own programs. Iyengar recalls that “The power of the computer still wasn’t enough when we were designing the Hancock Building or the Sears Tower. “We had to rely on our judgment first. Sears Tower could not be solved in any computer that we had, the structural analysis of it, but the computer improved the accuracy of what you were already thinking.’”
Following Khan’s death, Iyengar was named SOM Director of Structural Engineering and worked with Graham on the cable-stayed addition to McCormick Place North, later declared a structural masterpiece by Tribune architectural critic Paul Gapp (Kamin, 2019). In 1990, Iyengar created a story familiar to Chicagoans by using air rights to build the Broadgate Exchange House in London. The Exchange House—part bridge, part office building—spans working railroad tracks with the help of distinctive parabolic arches.
Iyengar consulted with Gehry on the Guggenheim and, with Zils was heavily involved in persuading Gehry to create a structure using steel instead of concrete. While Iyengar claimed less involvement with the Pritzker Pavilion, Gehry said otherwise. When questioned about the ability of the structure to handle Chicago’s wind and snow, Gehry declared, “I have one of the best structural engineers working on this project, Hal Iyengar of Skidmore, Owings & Merrill.”
Rounding out this trio of exceptional SOM Chicago office award winners is 2008 honoree William F. Baker, who joined SOM in 1981. Baker worked as a junior engineer under Kahn and as a senior engineer, “with John Zils and Stan Korista, and on several projects with Hal Iyengar.” (Structure Magazine)
Bill Baker adds “sustainability” to Zils’ “simplicity” and Iyengar’s “structural clarity” as the three attributes one would expect in an SOM building. The focus on sustainable solutions is Baker’s way of making buildings more efficient, and “enabling other designers to find the solutions easily.” “I remember hearing Khan give a talk where he said his goal was not to ‘patent, but to publish’ and then go on to the next idea before anyone else got there.” (Structure Magazine)
Baker partnered with SOM’s lead designer, Adrian Smith, on the Trump International Hotel and Tower and the Burj Khalifa. Speaking about the latter, Baker recalled Zils’ adage, “Always have at least one viable solution for every problem. Don’t draw a structure without having at least one idea of how it could be feasibly built”. (Structural Engineering Forum of India). That dictum led to the development of the buttressed structural system for the Burj and the core and outrigger system for the Trump International Hotel and Tower. These innovations “are all about the wind”, (New Atlas Magazine) he says, and Chicago will see Baker’s latest innovation up close and personal when his current engineering project, 400 N. Lake Shore Dr., opens.
In a WordPress interview from 2017, Baker said, “The John Hancock Center in Chicago is my favorite structure because of its clarity, the simplicity, and sophistication. The way it meets the ground, the way it tells its story.” Clearly, John Zils, Hal Iyengar, and Bill Baker, all CTBUH honorees from the Chicago SOM office, tell a sophisticated story about modern building systems. They have secured their place in structural engineering history and ensured that Chicago’s structural innovation continues to transform, advance, and sustain the world of architectural design.
Sources
Adriaenssens, Sigrid. “What I Am Thinking: Bill Baker at SOM.” Form Finding Lab, https://formfindinglab.wordpress.com/2017/03/15/what-i-am-thinking-an-interview-with-bill-baker/. Accessed 4 Sept. 2024.
Blum, Betty J. “ORAL HISTORY OF SRINIVASA (HAL) IYENGAR.” 2008. Art Institute of Chicago, Accessed 4 Sept. 2024.
Brunner, Lincoln. Roll with the Changes, 10 Nov. 2001, https://www.ffjournal.net/industry-news/1-uncategorized/6112-roll-with-the-changes.
Kamin, Blair. “Srinivasa ‘Hal’ Iyengar, Structural Engineer Who Helped Design Landmarks from Chicago to London to Spain, Dies at 85.” Chicagotribune.Com, Chicago Tribune, 10 July 2019. www.chicagotribune.com/2019/07/10/srinivasa-hal-iyengar-structural-Accessed 4 Sept. 2024.
Mas Context, “Building the Symbol of a Remarkable Transformation” Interview with John Zils, March, 2017.
Modern Steel Construction, “A Pioneer in Building-Tube Design, Construction, Willis Tower Turns 50”. May 24, 2023
New Atlas Magazine, “Interview with Bill Baker”, Adam Williams, September 2017
Structure Magazine, “Bill Baker”, June 2023
Subramanian, R. “William F. Baker of Skidmore, Owings & Merrill LLP (SOM).” STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI], 10 Feb. 2010, https://www.ffjournal.net/industry-news/1-uncategorized/6112-roll-with-the-changes.
“William Baker: Structural Engineer and Problem Solver.” Limitless Magazine, University of Illinois Urbana-Champaign – The Grainger College of Engineering , 25 Oct. 2023, grainger.illinois.edu/news/magazine/fall-2023/william-baker. Accessed 4 Sept. 2024.
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