VIDEO: London 2012: Aquatics Centre roof lift

Work is under way lifting the 2800-tonne wave-shaped roof of the Zaha Hadid designed London 2012 Aquatics Centre.

The lift is considered one of the most complex engineering and construction challenges of the Olympic Park ‘big build'.

Raising the roof

When complete the 160 m long column-free and up to 90 m wide 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 huge 30 m steel truss weighing over 70 tonnes has been lifted into place on top of the southern wall. This has already been connected with the first sections of 15 steel trusses which will span up to 120 m to the two northern roof supports.

Steel trusses fabricated in Newport from plate rolled in Gateshead, Motherwell and Scunthorpe, will be assembled on the Aquatics Centre site and connected 20 m above ground on three rows of temporary support trestles.

Once the huge steel roof frame is complete it will be lifted up to two metres at its southern end, turning on complex 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 at 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 steel frame is in place work will start on the aluminium roof covering. Installation will then start next year 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.

Aquatics Centre fast facts

• The Zaha Hadid designed Aquatics Centre is located in the south of the Olympic Park and will be the main ‘Gateway into the Games', hosting Swimming, Diving, Synchronised Swimming, Water Polo finals and the swimming discipline of the Modern Pentathlon
• The Aquatics Centre will have a capacity of 17500 during the Games, reducing to a maximum of 2500 in legacy, with the ability to add 1000 for major events, and provide two 50 m swimming pools, a diving pool and dry diving area - facilities London does not have at present
• Eleven industrial buildings have been demolished on the 55000 m2 site.
• Around 160000 tonnes of soil have been dug out of what was one of the more challenging and complex areas of the Olympic Park, contaminated with pollutants including petrol, oil, tar, solvents and heavy metals such as arsenic and lead
• Four skeletons were discovered and removed from a prehistoric settlement discovered on the site of the Aquatics Centre.
• 140000 tonnes of clean soil has been brought from other areas of the Olympic Park to prepare for construction to start.
• Planning permission has been achieved and Balfour Beatty is building the Aquatics Centre and huge land-bridge that forms the roof of the training pool and the main pedestrian access to the Olympic Park. Construction work will be complete in 2011 for test events ahead of the Games.
• The Aquatics Centre has been designed by Zaha Hadid Architects working with Arup and S&P Pool architects.
• The river that runs alongside the venue has been widened by eight metre by building 550m of new river walls.
• The huge completed southern roof support is 9m high, 28m long, over 5m wide, using 850m³ of concrete.
• A 3000 tonne concrete ‘bridge' has been built spanning and protecting the tunnels which have been dug to run powerlines beneath the site. The northwest roof support is being built on top of this base.
• Construction is well under way on the north-east roof support, with 8m high of concrete already poured.