Advanced geometry: engineering architecture at the Olympics

The Fabwin system divided the surface of the membrane into a collection of node points, connected by triangles. Each triangle pulled on its three nodes with a constant force, which moved the nodes around. After iterating this process over and over again, the system reached a point where every node was being pulled on with an equal force, meaning they stopped moving and entered a stable shape. Altering the weight of the rings and ballast on the membrane, and the amount of stress, changed the stable form and allowed Kapoor to sculpt the shape he wanted.

Balmond’s team then had to install the sculpture, and settled on using the overhead gantries that support the Turbine Hall’s cranes. The sections of tubular steel that formed the lattice were formed into the huge rings using induction bending, and the rings suspended from the gantries at either end of the building. The concrete floor of the gallery took some of the weight, and two additional sections of steel tube for each ring passed some of the load onto the former power station’s roof structure.