Pavilion 12 – with outside dimensions 120x120 m – has a free-spanning cable suspended steel roof structure without internal columns. 32 cables span over a length of 112 m between a circular primary steel ring which is supported by composite columns. A 3D system consisting of ring beams, radial lattice girders and polygonal purlins perform this wide spanned roof structure. Waagner Biro Steel and Glass´s scope covers the optimization of the weight of the steel structure (1,400 t), the basic design and the delivery and installation of the steel cables.