The tripod features a 60m high vertical back leg and two 70m long splayed front legs, all triangular in section and formed from 100mm to 120mm thick sections, with a central hub, constructed from 100mm thick plates welded together, at the point where the legs meet.
The erection process involved hoisting the tripod up using a temporary mast and guy cables, with the tripod’s back leg positioned on a moving bogie, before it was bolted into place.
It also features a 20m diameter top ring, made from a circular section 1.6m in diameter and 40mm thick, which gathers the cables together.
The next phase will see the attachment of the cable net to the 20m diameter top ring. The latter is free to move on a series of struts, each positioned on two sets of bearings to reduce loading on the tripod. An ETFE cushion cladding, which will allow daylight into the tent as well as protect inhabitants from the harsh external climate, will then be clamped to the net using aluminium extrusions.
Architects Fosters + Partners and consultant Buro Happold were appointed by design and build contractor Sembol in late 2006 to jointly deliver the concept and the scheme design.