"A Convention Hall. A Co-operative Project" (MS 1954)

Advisor: Ludwig Mies van der Rohe and Ludwig Hilberseimer
Others acknowledged: Reginald Malcolmson and Frank Kornacker

Material: Steel
Structural system: Two-way truss roof system with diagonalized perimeter and wind bracing system, supported on twenty four (24) perimeter piers.
Maximum span: 720 ft.

“Since structure in our philosophy of architecture and in this technological era, is the very essence of form, its orderly discipline must not be violated. The clarity of the structure, maintained by the proper placement and usage of materials, can enhance to a greater degree the monumental proportions of this structure.”

In November 1953, Mies van der Rohe presented his proposal for a new convention center for the city of Chicago, which he worked on together with Frank Kornacker as structural engineer and three graduate students from IIT. After this collaborative work, the students continued working on the proposal that they submitted as a joint master thesis in June 1954. As they explained in the preface: “This thesis was the result of an extensive group study on a project proposed by Mies van der Rohe for a convention hall in the City of Chicago. The background research was undertaken as a group, structural problems were furthered by Miwa, the architectural problems by Kanazawa, and the enclosure problems by Chang.”

“Engineering solutions are often based on minimums. Architecture can not disregard the economy of means towards the fulfillment of an idea, for this is a law of nature. However, by economy is not meant the economics of book-keeping. Economy implies a balance - order, clarity and harmony - in the totality of interdependent elements, each element weighed against the others never alone as a matter of economics nor of minimums. Architectural solutions should be concerned with the optimum. The cathedral of the Middle Ages embodies economy of means in its structure of forces. It is not a structure arrived at with the aid of differential calculus but with intuitive sense of forces and counterforces, qualities more necessary indeed to a real architect than a full knowledge of mathematical intricacies.”

The type of the structure finally chosen by the students was a seven hundred twenty foot span two-way truss system, thirty feet deep with members spaced thirty feet center to center each way. The system is supported by five columns on each side of the structure and having a cantilever of one-hundred-twenty feet on both ends of the truss. “From the standpoint of structure, it is clear and is simple to fabricate and erect. After much study of the proportions of all the elements of the structure in model form, it was considered the best solution from the standpoint of architecture.”

“There are two types of bracing: one is in the horizontal plane and the other is in the vertical plane. The horizontal bracings are located at two different levels. One is in the plane of the lower chord of the two-way truss system; the other is a thirty feet deep horizontal flat Pratt truss, its outside chord connected to the columns and its inside chord suspended from the roof structure, sixty feet above, by a steel plate at each panel point. The vertical bracing is located in the plane of the columns at a forty-five degree angle.”

For the connection between the perimeter supports and the foundation, a steel column system and concrete pier system were both studied as possibilities. The section of the column member remains uniform, the steel column system extends down continuously to the base plate, but the steel column of the concrete pier system is terminated at the top of the concrete pier twenty feet high above the ground level. This last solution was finally chosen.

“A large space completely free of interior columns is feasible from an engineering, architectural, and aesthetic standpoint. The freedom and flexibility of the created space must not be destroyed by the improper placement of the required physical elements.”

Once the structure is determined, the problem of enclosing the space still remains. After trying different materials - marble, granite and metal - and several colors of each. Finally, the proposal based on two colors of metal-panel was chosen. These panels would be between the structural elements, allowing the hall to have the same expression from the outside as from the inside. “The building itself is a metal structure of vast dimension, and a metal enclosing surface seemed to bear a close relation to the metallic quality of the building.”