TALK Thinner Than Eggshells. Speaker: John Chilton

Heinz Isler’s shells for the former Norwich Sports Village The recently-listed, reinforced concrete shell roofs at the former Norwich Sports Village are unique examples in the UK of free-form shell architecture. First developed in Germany, in the 1920s, thin reinforced concrete shells are relatively thinner than eggshells. Early concrete shells were based on geometrically definable forms – domes, cylindrical vaults, conoids and hyperbolic paraboloids. However, in 1959, at the First Congress of the International Association for Shell Structures, the Swiss engineer Heinz Isler (1926-2009) astounded the international audience of eminent engineers and architects by presenting three ingenious methods for creating non-geometric, free-form shells. The most novel of these was the ‘hanging cloth reversed’. This was the technique he used to find the shape of the sports hall and swimming pool roofs of the Norwich Sports Village, opened officially by Princess Anne, on 8th September 1988 This talk will describe Heinz Isler’s formative years, including the design and construction of the former Norwich Sports Village swimming pool roof. John Chilton is Emeritus Professor of Architecture and Tectonics at the Department of Architecture and Built Environment, University of Nottingham, and Honorary Member of the International Association for Shell and Spatial Structures, based in Madrid. He was a long-standing friend of Heinz Isler and is author of the book The Engineer’s Contribution to Architecture: Heinz Isler (2000). He had the good fortune to witness the first day of concreting the Norwich swimming pool shell.