Seventh International Congress on Construction History, Lisbon 12 - 16 July 2021

Susanne Brunner

Transparent acrylic constructions before and after 1950 - from the 1935 Opel Olympia to the 1972 Olympic roof

Keywords: acrylics, lightweight construction, propaganda, production processes, Olympic roof Munich

Abstract

Transparent acrylics are a relatively young, but nevertheless conflicting building material. The cultural meaning of the synthetic changed drastically before and after 1950. This discrepancy is nowhere more obvious than in Germany, where Röhm & Haas has been producing sheets of Polymethyl methacrylate (PMMA) since the first year of the National Socialist regime. Mass fabrication led to a wide use of transparent acrylics in the automobile and aircraft industry especially for military purposes. At the same time, transparent construction elements were used in the context of political propaganda, showcasing German technologies and technological progress. Just as the transparent, crystal like lectern made of PMMA for Adolf Hitler, the Opel Olympia exhibited at the international automobile congress 1937 in Berlin with its “glass” integral body is exemplary for the early fascination and stunning impression of a seemingly dematerialized substance.

In the postwar period, on the contrary, transparent PMMA became associated with democratic ideals and airiness and American values – not least because of the commercial success of Plexiglas® products by the American partner company. New production technologies for the thermoplastic material, especially extrusion and stretch forming, as well as additives enforced the material’s usage in the building industry. Transparent construction elements for roofs, skylights like cupolas, windows and balustrades allowed seemingly light structures that are contrary to the monumentality of buildings of the 1930s and 1940s. Most obviously, in the roofing of the Olympic sports facilities of 1972 in Munich transparent acrylic elements represented a new Germany to an international audience. In deliberate contrast to 1936, a friendly, open space was created for a jolly event in the green. With its high impact resistance and good fire protection qualities, biaxially stretched Plexiglas® was chosen as roofing material. Unfortunately, acrylic constructions were not foreseen to last for long and often altered over the years, when the glasslike PMMA became opaque, white and brittle under the influence of UV-light, gasses and water.

In the proposed paper, the history of transparent PMMA as construction element will be introduced in regard to its shifting cultural meaning. The paper is based on an ongoing research project at the Professorship of Recent Building Heritage Conservation in cooperation with the Deutsches Museum and the Bavarian State office for the Preservation of Historical Monuments and funded by the Deutsche Bundesstiftung Umwelt. The project deals with the conservation of outdoor transparent acrylics in cultural heritage objects in an interdisciplinary approach.