Erection of the Cable Net Roof for the London 2012 Olympic Stadium

Designed by Populous (architects) and Buro Happold (structural engineers) and fabricated and erected by Watson Steel Structures Ltd, the roof over the London 2012 Olympic Stadium covers an area of more than 24,500m². The construction of the cable net roof posed many complex engineering problems, culminating in the erection of the 14 lighting towers, perched on the leading edge of the roof and supported by a secondary cable net. The entire main cable net, including access gantries, was lifted in one operation involving the simultaneous operation of 28 pairs of strand jacks to lift and pre-stress the cable net roof structure. The design of the staged lifting procedure meant that no additional strand jacks were required for the connection of other cables. An innovative method of lifting the lighting towers into position, using a single crane, was developed to save time and avoid the use of a second crane in a tight location. This paper covers the fabrication of the roof elements, the staged erection and pre-stressing of the main cable net and also the erection of the stadium's signature lighting towers.