Sydney Opera House (Sydney Ooperimaja)
years. The project was not helped by the changes to the brief. Construction of the shells was
one of the most difficult engineering tasks ever to be attempted. The revolutionary concept
demanded equally revolutionary engineering and building techniques.
From 1957 to 1963, the design team went through at least twelve iterations of the form of the
shells trying to find an economically acceptable form (including schemes with parabolas,
circular ribs and ellipsoids) before a workable solution was completed. The design work on
the shells involved one of the earliest uses of computers in structural analysis, in order to
understand the complex forces to which the shells would be subjected. In mid-1961, the
design team found a solution to the problem: the shells all being created as sections from a
sphere. This solution allows arches of varying length to be cast in a common mould, and a
annaabi.ee 
