This paper presents original research on two historical developments in the field of thin-shell concrete structures in the United States, both at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts in the 1950s. The first topic is the design and construction of MIT’s Kresge Auditorium (1953-1955), enclosed by a concrete shell on three supports designed by architect Eero Saarinen (1910-1961). The second topic is a seminal conference on the architecture, engineering, and construction of thin concrete shells hosted by MIT in 1954, which included presentations by architect-engineer Felix Candela (1910-1997), engineer Anton Tedesko (1903-1994), architect Philip Johnson (1906-2005), among many important designers and scholars. Both the building and the conference are historically significant, and together, they mark the peak of a design era optimistic about the enduring value of thin-shell concrete structures. However, they also reflect the underlying tensions and contradictions of thin-shell concrete technology that contributed to its limited use in subsequent decades. The project therefore serves as an early example illustrating the limitations of thin-shell concrete applied to arbitrary formal ideas. The concurrent conference often related directly to the design and construction of Kresge Auditorium: both its structural engineer (Charles Whitney, Ammann and Whitney) and contractor (Douglas Bates, George A. Fuller Company) presented papers, and a proceedings summary notes that “this conference has…cantilevered out from Saarinen’s dome.” The conference highlights broad enthusiasm for thin-shell concrete structures, but also reveals disagreements between theoreticians and practitioners, architects and engineers, and designers and builders. This paper gives a critical review of the influential conference, based on conference proceedings and supporting historical documents. In summary, this paper contributes new knowledge on the history and significance of paired events in thin-shell concrete in the 1950s at MIT. In addition to detailed accounts of both the building and conference, the paper offers original insight about their contextual role in the rise and fall of thin-shell concrete technology in the design and construction community. 1 Building Technology Program Massachusetts Institute of Technology, 77 Massachusetts Avenue, 5-418, Cambridge, MA 02139, wplunket@mit.edu 2 Building Technology Program Massachusetts Institute of Technology, 77 Massachusetts Avenue, 5-418, Cambridge, MA 02139, caitlinm@mit.edu Thin Concrete Shells at MIT: Kresge Auditorium and the 1954 Conference 5th International Congress on Construction History HISTORICAL CONTEXT Thin-shell concrete is one of the most important developments in twentieth century construction history. Formalized in the 1920s in Germany by Franz Dischinger and Ulrich Finsterwalder (May 2012), this material and structural system have been used to achieve great spans, unprecedented material efficiency, and dizzying geometric complexity that captured the imagination of the modernist movement in architecture. But thin-shell concrete structures also embody a fundamental contradiction: on the one hand, they offer an infinite spectrum of possibilities for new structural shapes, as described by engineers like Heinz Isler (Chilton 2010). On the other hand, their success depends on a precise and sometimes intractable relationship between geometry and structural behavior; just because a shape is rendered in thin concrete does not mean it behaves as an efficient shell. This paper is about this fascinating contradiction, which lies at the root of the welldocumented rapid rise and subsequent decline of thin concrete shells in the post-war American architecture and engineering (Billington 1983). This paper examines this trajectory through the lens of a particular moment and place, 1954 and the campus of the Massachusetts Institute of Technology (MIT), a snapshot that reveals a critical shift for how thin-shell concrete structures in the United States would be perceived and constructed during the Post-War period. Three events in Massachusetts occur in June 1954, and each provides a different perspective on the nascent interest in thin-shell concrete as a means for architectural expression and structural efficiency. First, the construction of Eero Saarinen’s Kresge Auditorium, a shell shaped like one-eighth of a sphere and supported on only three points, on the MIT campus is underway (Figure 1). The concrete pour for the shell was completed in April 1954 (Boothby et al. 2005), and the removal of the supporting formwork led to substantial deflections at the free edges, much larger than anticipated. The contractor, George A. Fuller Company, and the engineers, Ammann & Whitney, developed a solution: strengthening nine of the vertical window mullions, originally designed for horizontal wind load only, to support the gravity load of the shell along its free edges, as shown in Figure 2. The existence of the supporting mullions was not publicly disclosed until September 1954, three months after the conference at MIT, in an article by Joseph Lacy of Eero Saarinen and Associates stating, “At a meeting of all interested parties it was decided to substitute three struts for the same number of window mullions at each edge beam, in order to fix the elevation of the edge beam” (Lacy 1954, Zakem 2006). Second, the 1954 Conference on Thin Concrete Shells is hosted at MIT on June 21-23, 1954 by the departments of Architecture and Civil Engineering. Two primary themes emerge: an optimism and intrigue in the possibilities that thin concrete shells could achieve, both in terms of architectural innovation and structural resiliency, and a vigorous debate on the best approach for engineering such forms, argued between those who favored rigorous calculations and those who preferred empirical approaches. The engineering firm and contractor responsible for Kresge Auditorium are present at the conference, and speak proudly about the project without mentioning the large deflections and necessary changes. Third, separate from the MIT conference, the 86th Convention of the American Institute of Architects also occurs in Boston in June 1954 with Saarinen, designer of Kresge Auditorium, featured as a speaker. In his speech, “The Changing Philosophy of Architectures” he outlines the specific approach he used for the design of Kresge, a view he reiterates and refines over the course of the decade. He states, “The Structural Principle: From as far as I can remember in modern architecture, structural integrity and structural clarity are basic principles. In recent J. W. Plunkett and C. T. Mueller 5th International Congress on Construction History years, these principles have received a new impetus…An example of what I mean is demonstrated in the domed auditorium we are building for MIT” (Saarinen 1954). Notably, any discussion of the flawed structural performance of the Kresge Auditorum is absent from this discussion.
