London 2012 Aquatics Centre roof reaches half-way point

New images from the London 2012 Olympic Delivery Authority (ODA) show the wave-shaped roof of the Zaha Hadid designed Aquatics Centre has reached the half way point.

Lifting the 160 m long, 90 m wide 2800 tonne roof started three months ago and is considered one of the most complex engineering and construction challenges of the Olympic Park ‘big build'.

When complete the column-free roof will rest on two concrete supports at the northern end and a 28 m long and 5 m wide, supporting ‘wall' at its southern end.

A 30 m steel truss weighing over 70 tonnes has been lifted into place on top of the southern wall and this been connected to ten steel trusses each made up of four sections each which in total will span up to 120 m to the two northern roof supports.

Steel trusses fabricated in Newport, Wales from plate rolled in Gateshead and Scunthorpe in England and Motherwell in Scotland, are being assembled on the Aquatics Centre site and connected together 20 m off the ground on three rows of temporary support trestles.

Twenty six trusses are in place and once the steel roof frame is complete this summer it will be lifted up to 2 m at its southern end, turning on rotating joints in the northern roof supports. The temporary trestles will be removed and the 160 m long roof frame lowered on to its three permanent roof supports, which have been built with over 20000 tonnes of concrete.

As the full weight of the roof rests on its supports it will slide approximately 200 mm into its joints on the southern wall. The roof has been designed, through wind tunnel testing and computer modelling, to stretch, twist and contract in response to the effects of snow, wind and changing temperatures.

Once the roof is in place work will begin on the aluminium roof covering. Installation will then start in 2010 on the timber cladding of the ceiling, which will "sweep outside" to cover the northern roof supports.

The foundations of the permanent venue are complete and work will begin on the pool structure once the steel roof is complete.

The Aquatics Centre will be the gateway to the Olympic Park and in legacy will provide two 50m swimming pools, a diving pool and dry diving area - facilities London does not have at present.

Construction of the venues and infrastructure of the London 2012 Games is funded by the UK's National Lottery through the Olympic Lottery Distributor, The Department for Culture, Media and Sport, the Mayor of London and the London Development Agency.