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21 The Olympic Basketball Arena has been designed for international service beyond the 2012 Games, as Jess Unwin explains London s 42 million Olympic Basketball Arena could herald a revolution for the planet s biggest sporting event. Two-thirds of the materials in this extraordinary temporary venue can be reused after competition is over, which means it is possibly the first of many big tops that could make up a globetrotting Olympic circus. The 2012 Games already show a shift in Olympic thinking. No future competition is likely to get the same kind of massive funding as the 2008 venue Beijing, where the authorities are still trying to find viable future uses for specially built, permanent structures. In a world with economic woes and dwindling natural resources, the recyclable basketball arena has sustainability appeal. It can be used many times theoretically anywhere. Barclay Chalmers, managing director of Paisley-based main contractor Barr Construction, says: It was always in the brief that the structure should be temporary so it could be put up and then taken down fairly easily. It was certainly a challenge. The major difference was that a lot of work went into the steel frame of the building. We usually design something to stay there forever. In fact it has been suggested the 12,000-capacity basketball stadium might be part of the 2016 Games in Rio de Janeiro. Barr, which will likely take ownership of the arena once the Olympic Delivery Authority (ODA) has finished with it, will dismantle the venue and then begin looking for ways to reuse it. ODA project sponsor Richard Arnold says: We don t think an Olympics has ever built such a big temporary arena before. The International Olympic Committee and other Olympic bodies are quite keen on what we ve done here in London. This could well set a model for future Olympics, particularly with more developing countries looking to potentially Continued overleaf...
22 This could well set a model for future Olympics, particularly with more developing countries looking to potentially make bids Richard Arnold, ODA project sponsor make bids. Having the ability to move venues around the world is something that could be very appealing. It s affordable and sustainable. You build what you need to and then look at temporary structures and how they can be used afterwards. Versatility is the other main feature of the Basketball Arena, since it will be hosting not only the basketball tournament, but also the semi-finals and final matches of handball, as well as the wheelchair basketball and rugby championships for the Paralympics. During the Olympic Games there will be just 22 hours to transform the venue from basketball to handball use. This will include removing the basketball posts and installing the handball goals and field of play mat. Afterwards, during the Paralympic Games, there will be just 12 hours to get ready for wheelchair rugby after the wheelchair basketball finishes, with similar changes needed. Construction on the Basketball Arena began in October 2009, with work to erect the 1,000-tonne steel frame starting in March 2010. Construction was completed within budget in June 2011. Richard Arnold explains that the building s steel frame is wrapped in 20,000 sq m of recyclable white PVC membrane that is stretched over three different variations of arched panels. This outer structure forms an overall enclosure and its pattern of edges and planes has been likened to some sort of giant, sculpted mattress or cake! The exterior also becomes a kind of canvas for an innovative, changing night-time lighting display. In detail, the steel skeleton is a series of curved latticed steel roof trusses and tapered 23m-tall vertical legs forming a 35mhigh portal frame that spans 96m, which together with the 'lean-to' gable end portal frames results in an overall building length of 115m. Valley cables within each of the 6m-wide primary roof bays provide the tensioning system for the saw-tooth membrane cladding system. Façade designs were developed in conjunction with architect Wilkinson Eyre and resulted in sets of varying diagonal arch forms that create an apparent random series of barrel vaulted wall panels. Steel framing design and details were developed to incorporate and integrate the fabric tensioning systems, a high-level siphonic drainage perimeter gutter and louvres that provide the passive ventilation system. Inside, the seating bowl around the field of play is completely separate and is essentially a scaffolding structure. The back of this has PVC-based plastic wrap around it to create a near hermetically sealed space and create the right conditions for the passive ventilation system. Toilet facilities are under the seating and refreshments will be served in temporary facilities outside the arena.
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24 Events basketball, wheelchair basketball, wheelchair rugby and the final stages of the handball competition Cost: about 42 million One of the largest temporary venues ever built for the Olympic Games The main structure will occupy an area similar in size to two football pitches Fourth-largest venue on the Olympic Park To accommodate the basketball players, many of the venue s doors are required to be an above-average 2.4m high 12,000 seats in black and orange to represent the colours of a basketball The venue is 35m high (as high as the Tate Modern) 1,000-tonne steel frame wrapped in 20,000 sq m of recyclable white PVC membrane, stretched over three different variations of arched panels During the Games the exterior will act as a canvas for an artistic and innovative lighting design After the Games the venue will be dismantled, with the option of potentially reusing it at other UK and overseas events. Richard Arnold adds: The main element of innovation was around the fabric enclosure in terms of how the PVC was put up. In many ways it almost used sailing technology in that the sections were pulled up like big sails on a ship and this was done by abseilers pulling them up to the top of the structure. That was quite interesting to see! Then there s the stretching of the PVC fabric over the steel frame. It all has to be stretched and stressed into place. The different shapes you see in the fabric are formed specifically, not just to give it a look, but also for functional reasons to give the overall structure rigidity. It s the combination of fabric and steel that gives the structure its rigidity. Although we were largely working with existing technology, it was the scale of the project that was the challenge. Besides much of the arena being reusable, Arnold explains that other sustainability considerations included bringing building materials on-site by rail and boat and attempts to minimise construction waste. Some parts of the building also benefit from siphonic drainage a system of air-free pipes that make the dispersal of rainwater much more efficient. At any one time a maximum of 200 people were on-site, including contractors more used to working in the world of temporary events so there were health and safety challenges in bringing them onto such a large mainly permanent building site.
25 It almost used sailing technology in that the sections were pulled up like big sails on a ship, and this was done by abseilers pulling them up to the top of the structure Richard Arnold, ODA project sponsor Arnold adds: All works had to be sequenced so as not to have contractors working all over each other and we had to look at logistics on a park-wide basis. Deliveries had to be managed by central systems you couldn t just bring in things, they had to be booked at least 24 hours in advance and had to go through various security checks. During the peak of construction we were having a delivery on the site every 15 seconds so all of that had to be fully managed. On top of that the workforce couldn t come on-site in their own vehicles so public transport and our own bus system moved workers around. The Basketball Arena design team was led by Sinclair Knight Merz, which was also responsible for the new Wembley and the Eden Project. The other design companies were Wilkinson Eyre and KSS Design Group. Companies from across the UK were involved in the construction. ODA chief executive Dennis Hone describes it as a tribute to the companies from across the UK involved in its delivery. Ricky Burdett, chief adviser on architecture to the ODA, praises the arena design team s ability to integrate structural integrity with architectural expression, backed up with experience, capacity, creativity and a deep understanding of the complex brief. London 2012 Organising Committee chair Lord Seb Coe says: Basketball is one of the most popular Olympic sports and spectators will be able to see the game played out in spectacular surroundings. The Olympic Games is not just a chance for young athletes to break new records but also an opportunity for architects, specifiers and everyone connected with the UK construction industry to create amazing structures and showcase their skills to the rest of the world. Design: Sinclair Knight Merz; Wilkinson Eyre; and KSS Design Group Main contractor: Barr Construction Piling: Steel Pile Installations Stone columns: Keller Ground Engineering Foundation works: SJW Civil Engineering Structural steelwork: Fenton Holloway; Watson Steel Structures Civils framework: Galliford Try Infrastructure Exterior membrane cladding, infill fabric and cable structure: Base Structures Roof cladding: Fenland Flat Roofing Syphonic drainage: Fullflow Group Temporary accommodation: McAvoy Mechanical and electrical works: Mitie Seating: Slick Seating Wrapping for seats: Envirowrap Steelwork, internal fit-out (including lifts) and toilet blocks: Volker Fitzpatrick