DELIVERING THE GAMES SUSTAINABILITY

The buildings are built to a BREAM level Most of the ODA’s work has been completed and I am four specification ensuring low energy and water use, while 200 apartments confident that next month London will be ready to host a are specifically designed for people with disabilities. truly unforgettable Games! In legacy mode, roughly half of the apartments will be sold as affordable homes with the remainder available for rent or especially on the Underground. A normal approach to programme control and change sale on the open market. The Village was day has in excess of three million journeys management, as well as strong assurance originally planned to be built by a private and the likely timing of those journeys has and risk management. sector developer and lent to LOCOG for the had to be taken into account relative to the I am glad to report that the ODA has Games. However, the financial crisis of 2008 start and finish times of the events. achieved a solid health and safety record. meant that funding was not available on The ODA has made an investment There have been in excess of 70 million hours sensible terms and too much risk would be of almost £900 million in transport worked with an accident frequency rate of left with the ODA. So it was decided to use improvements, with a total of £6.5 billion spent 0.17, well below the industry average. our contingency monies together with other by all bodies ahead of London 2012. These As part of its legacy, the ODA has savings to fund the construction and then have included expansion of the circulation published, in conjunction with various look to sell the village to recover the money. capacity of Stratford Regional Station, track professional organisations, about 300 This has now been successfully achieved layout changes to improve capacity, a new separate papers which identify lessons with the affordable homes bought by a Docklands Light Railway (DLR) station adjacent learned from the delivery of this major housing association and the market homes to Stratford International and co-funding programme. These can be found by a private sector consortium. In addition with Transport for London for the expansion on a dedicated public website, at to the housing, an 1,800-pupil academy has of the whole DLR service by the addition of www.london2012.com/learninglegacy been built along with a polyclinic for serving more carriages and longer platforms. Further With one month to go at the time of the legacy population. co-financing of improvements to the North writing, the Opening and Closing Ceremonies Extensive landscaping of the central London Line, with Network Rail, has increased have been planned and rehearsals are in open area of the Athletes’ Village includes capacity by 45%. progress. The broadcasters now have to the planning of a further 2,000 mature (up Park and ride services will also operate install their studios, cameras and miles of to 15 years old) trees and water courses around London, which, together with long cabling with 16,500 fixed telephones and that flow down to a wetlands bowl before distance coaches, will bring spectators to 7,000 internet stations across 894 locations. feeding into the River Lea. A further 8,000 a special transport mall being built on the In addition, 75,000 volunteers are being A view from trackside of the Olympic Velodrome on the first day of the UCI Track World Cup held in February 2012 © David Davies/PA Wire homes are planned for the Olympic Park Hackney Marsh playing fields adjacent to the recruited and trained and 65 hectares of tents during the next 20 years. A12 at the north of the Park. erected for retail, catering and back-of-house facilities. The security channels, similar to an airport, are being installed and temporary TRANSPORT TO SUM UP hired seating erected at locations such as Transport is a vital aspect of any Olympic The infrastructure for the 2012 Games has Greenwich Park for the equestrian events, Games, highlighted at the Atlanta Games been delivered on or ahead of time and Eton Dorney for the rowing and Horse Guards in 1996, when athletes missed their events under budget. The principal reasons for this Parade for beach volleyball. are that there has been cross-party political THE OLYMPIC because of transport problems. Transport is Most of the ODA’s work has been not only central to the athletes’ state of mind support, a fixed deadline, early attention completed and I am confident that next and preparation but also for the officials who to governance structures, a sensible month London will be ready to host a truly move around between different venues, in budget, clear client leadership, a rigorous unforgettable Games! addition to the hundreds of thousands of VELODROME spectators travelling every day of the Games. The whole transport operation has to BIOGRAPHY take place while keeping London and the Sir John Armitt CBE FREng FICE, was appointed Chairman of the Olympic Delivery UK moving. In line with the city’s aim of Authority in September 2007. Sir John was previously Chief Executive of Network Rail The 6,000 seat Velodrome is the most energy-efficient of the from October 2002 and Chief Executive of Railtrack plc from December 2001. He has hosting a ‘public transport’ Games the base extensive experience in the building, civil engineering and industrial construction permanent Olympic venues and, for many, the most beautiful planning assumption has been that 80% of markets. From 1986 to 1993 he was Chairman of the Laing International and Civil building in the Olympic Park. It has already won the Supreme spectators will choose rail as their preferred Engineering Divisions, a company he joined as a graduate in 1966. From 1993 mode of travel. The remainder will travel by to 1997 he was Chief Executive of Union Railways, the company responsible for Award of the Institution of Structural Engineers, and was the bus, coach, park and ride, water taxi and the development of the high speed Channel Tunnel Rail Link. In 1997 he was appointed most sustainable modes, those of walking as Chief Executive of Costain, a position he held until 2001. He was Chairman of the runaway winner of the ‘people’s poll’ for the RIBA Stirling Prize. and cycling. Engineering and Physical Sciences Research Council from 2007 until 2012. Ingenia reports on the engineering behind the design and The planning by the ODA of the construction of the Velodrome. transport requirements has had to recognise This article is based on the Lloyd’s Register Educational Trust lecture given by Sir John Armitt in the 800,000 extra journeys likely to be taken, December 2011 for The Royal Academy of Engineering

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Aluminium standing seam roof

300 mm insulation providing overall U value of 0.15 W/m2K

Vapour barrier

arearre stacked highest at than a conventional steel arch the rim of a rigid bowl, then the Timber roof cassette with birch- thet centre of the roof. This was partly thanks to bowl could help resist much of faced plywood soffit incorporating steel corner brackets straights. If a roof the amount of material saved by the tension, and the frame could is then ‘shrink using a cable-supported structure. be made much smaller.

wrapped’ over Despite a much longer lead-in This was the option chosen. Fabricated steel powder-coated the combined time for ordering the cables, it The 48 steel rib trusses of various receiver brackets with PFTE coating shape of track and would save time; and because lengths on which the roof to underside seating, the result the roof would be assembled on sits, and their associated cross is a double-curvature the ground before tensioning, it bracing, may appear to be doing Fabricated steel powder-coated connection plate with PFTE shape,shap highest over the would be safer to build. little more than supporting the coating to top. Combination of Steel powder- The starting point for the top seating and lowest over the roof and the tiers of seating, but fixed, slotted and oversized holes coated washers competition-winning design of apex of the bends. structurally they are working varies with location the Olympic Velodrome was, Expedition recognised STRUCTURAL exceptionally hard in transferring Nut appropriately enough, Victoria immediately that this shape SOLUTIONS as much as 75% of the load that Pendleton’s carbon fibre racing lent itself to a cable net design, would otherwise be carried by Galvanised forged steel The design presented Expedition top cable clamp bike. Built for speed, it has with the rising and falling cables with two enormous challenges. the ring beam down through everything trimmed down to the acting against one another The first was how to contain the the concrete substructure into minimum. The bicycle inspired to give a roof structure which tension in the cables. The roof is the foundations beneath. This the team tasked with designing remained stable and in tension a little like a giant warped tennis has saved a massive 2,000 tonnes and building the stadium and in all loading conditions. racket, and just as a tennis racket of steel from the structure and provided them with their guiding Despite uncertainties about needs a stiff frame to hold the means that the ring beam is all mantra: to ‘Do more with less’. the cost and risks of trying out a strings, so a traditional cable but invisible at the high points. Galvanised forged steel The build-team responsible technique that, though widely net roof requires a massive ring The second big challenge middle cable clamp with for the Velodrome at the used internationally, had rarely was movement of the roof. paired 36 mm diameter beam. But this beam would cables at 120 mm centres Galvanised forged steel Olympic Park in Stratford before been used successfully have been extremely heavy, and Cable nets need to move with bottom cable clamp were: Hopkins Architects; in the UK on such a high-profile would spoil the elegant lines of changing loading conditions, and structural engineers, Expedition; site, they were supported by the the top edge of the structure. this is relatively straightforward the contractors ISG and winning contractor who believed However, if the frame of the if the roof surface is a simple An exploded view of the cable connections to the roof. These connections An exploded view of the Velodrome showing key elements. From top: environmental services take into account the complex differential movements between the cable net the cable roof, the upper seating, the upper bowl, the lower bowl and the that the net would be cheaper tennis racket could be fixed to flexible membrane. However, the and roof cladding © Hopkins Architects foundations © Expedition engineers BDSP. The resulting building, with its distinctive double-curvature ‘Pringle’- Velodrome needed high levels of independently of its neighbour thus holding each panel in place or snow, or for the various stages shaped roof, has received insulation of the roof. Added to as the roof flexed? Allowing but allowing sufficient movement of the erection procedure. Also plaudits for creating a structure that, the ODA planners wanted also for tolerances and the in any direction. the roof, the steel structure and that has economised on the use an aluminium standing-seam vagaries of the roof’s geometry, With the panels in place, the concrete substructure could of materials, allowed minimal roof surface, which is attractive differential movements of up to 300 mm of insulation was added. not be analysed separately as interior volume for heating, and long-lasting but rigid with 30 mm in any direction had to Then the ‘Kalzip’ aluminium roof they all formed part of the same, created a shape that is suited large thermal movements. This be accommodated (the roof can was laid in strips up to 130 m connected structure, and a for natural ventilation and that required some very careful move/deflect by +/- 500 mm long: it is free to expand and change of loading on the roof was quick, economical and safe thought about the detailing. vertically, under wind and snow). contract along the length of the would affect everything else. to build. The net itself is made up The solution was an standing seam, with movement The design team was of pairs of 36 mm diameter ingenious detail at every point joints in the transverse direction. determined to keep materials DESIGN CONCEPTS spiral strand cables on a 3.6 m where the cables cross: a bracket, to a minimum, so each element The centrepiece is the oval grid, locked together with which sits on each of the forged of steel or concrete was made timber track (see The Cycle Track), forged steel nodes at each steel nodes and supports a CHECKING STRESSES to work extraordinarily hard. and the design team’s task was cable intersection. The roof is corner of each of four panels A further challenge for Furthermore, they could not be to wrap a building around it. built up from more than 1,000 independently. For each panel, Expedition was the sheer sure whether the Velodrome As with all velodromes, the seats plywood-faced panels matching one corner is fixed at the node, scale of the structural analysis would behave as a ‘stiff’ or a ‘soft’ are located predominantly along the size of the 3.6 m grid. But an adjacent corner has a slotted required. There was a large structure, so they modelled and Above: An early visualisation of the Velodrome with its ‘Pringle’-shaped roof, showing the VeloPark’s road track the straight sides of the track alongside © ODA Top: Victoria Pendleton’s competition racing bike, a masterpiece of minimalist design and inspiration how could each of these rigid connection, and the other two combination of different loading analysed both alternatives with where sight-lines are best, and for the Velodrome © Hopkins Architects panels be allowed to move corners have oversized holes, conditions, for example for wind many sensitivity tests.

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It is doubtful if any roof in history has been so The primary tool was Oasys completed structure. The node GSA finite element analysis clamps were fixed, creating the THE CYCLE TRACK thoroughly analysed. The result is a structure software, backed up by a series finished grid. With a safety net In complete contrast to the Velodrome structure, which has tight bends, some fatter and more oval shapes; some have steep of non-linear analyses and much fitted beneath, the cables were been designed using the most sophisticated modern analytical banking, some less steep. The ODA decided on a ‘Ron Webb’ as light as the design team dare go. post-processing of data to tensioned from the ends with techniques, the track design has something of the feel of track, and the former track cyclist and Australian champion who check, for example, the effect of electric winches and pulleys, early 19th century engineering about it, based on instinct designed tracks for both the Olympics and the Manchester movement on each and every gradually lifting the cable net and experience. Commonwealth Games was enticed out of retirement. component. It is doubtful if into place. The whole process The sport’s rules on track design are remarkably open: the track A Ron Webb track is on the ‘fat’ side, with radii of about 25 m any roof in history has been so took just eight weeks. The must be exactly 250 m long on the inside line and 7 m wide, and on the inside line, banking of 42° at the apexes of the curves and thoroughly analysed. The result cables were tensioned and then have a straight-ruled cross-section. Just about everything else 12° on the straights, and is surfaced in Siberian pine, laid in 40 mm is a structure as light as the the panels could be fitted one – the radii of the curves, the steepness of the banking, even the by 40 mm laths mounted on a substantial timber framework. The design team dare go. by one, working inwards from material of the surface – is up to the designer. ‘black art’ comes with the transition curves and the rate of change As the structure began to the edges. The final roof weight Were the track to be used for four-wheel vehicles travelling of banking, which differs considerably between the run in to the take shape, the cables were including cables, the slimline at a constant speed, the optimum shape would be calculable, curve and the run out. being manufactured in Germany. ring beam, timber cassettes, with the banking precisely countering the centrifugal forces. But The track was built in just eight weeks, under Webb’s close Each cable was cut to the insulation and finishes averages the competition cyclist is on two wheels, and the rider’s centre supervison, by PJ Lane from County Cork and his 25 carpenters, correct length and prestressed out at just 68 kg/m2. of gravity will be constantly changing, due to aggressive riding a team which Webb has worked with all over the world. Earlier, to its design loading in the At one stage, the design or sudden changes of direction within a field of riders. Speeds Webb had provided the Velodrome design team with the main factory, and the exact position team was under pressure will vary accordingly, with riders sometimes slowing to a virtual parameters of the design, sufficient to allow the seating to be laid of each node clamp marked to improve the structure’s standstill before sprinting off. out with proper sight lines to match the changes in grade of the (within 2 mm), before the load outwardly visible environmental Over the years several top designers have emerged, and each banking. To their great relief, the finished track was a close match was released and the cable credentials by adding a large has developed his own ‘signature’ design features to address and world records were established in the first World Cup match coiled and packed for shipping. array of photovoltaic cells on these requirements. Some prepare narrow-shaped tracks with held there in February 2012. At Stratford, tower cranes the roof. That would have were used to drape each added around 60 t to the roof The steel structure, awaiting the roof, showing the twin ring beam – the ‘warped’ tennis racket frame – with the ‘rigid bowl’ of the 48 rib trusses which helps to cable roughly into position load. Better, they reasoned, to strips of rooflights into the transfer the tension from the cables down to the foundations © London 2012 on the ground, over the part- save electricity by incorporating roof, with diffusing glass to avoid glare on the track (see Sustainability). For the Olympics (and a few other major events each year) high-intensity lighting is provided, but for training and minor events this natural lighting will suffice. BUILTIN FLEXIBILITY The full 6,000 seating capacity is only likely to be needed for these occasional major events. Hence the main banks of seating are separated into two tiers, with Cross section at the highest point of the roof, showing how the chimney effect promotes natural ventilation. Cables draped over the part-completed arena awaiting lifting and then later during the cable lifting sequence showing the node-connections and cable connections just the lower tiers used for more Cool air is pulled through low level louvres and exits at high level. These louvres form the distinctive pattern in © Expedition regular, minor events. the outer cladding © BDSP

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Heating and cooling were given careful treatment, partly SUSTAINABILITY to cope with the unusual The Velodrome is the Olympic Park’s flagship sustainable building, with the lowest level of embodied requirements of the venue and carbon per square metre of floor area – and far lower than most other stadiums, including the main Careers with energy partly to avoid waste. Cyclists stadium at the Beijing Olympics. require high temperatures – Much of this was achieved by minimising the amount of material used, and thereby reducing the 26°C or more – to reduce air embodied and operational energy. Also, ‘shrink wrapping’ the roof reduced the volume of air which resistance so that they can needed to be heated by 15% compared with the original design. Unleash yours. achieve record-breaking times. Designing for maximum daylight by incorporating rooflights, boosted during major events by But they also hate drafts; the energy-efficient artificial lighting linked to an intelligent control system, was found to offer far greater cyclists need warm, still air reduction in carbon emissions than ‘bolt-on’ technologies such as PV cells. without distractions if they are The main arena is highly insulated and fully naturally ventilated in mid-season and summer, reducing to achieve record speeds. The energy demand, and supplementary heating is carefully targeted. Rainwater is harvested from the roof, solution was to engineer three and is used for toilets and wash-down points as well as for irrigation of the VeloPark after the Olympics. Got ideas? Let them types of heating: underfloor Heating comes from the Olympic Park’s biomass boilers and combined heat and power (CHP), with heating in the infield, providing 2 electricity also from the CHP plant. Overall CO2 emissions of the building are just 67 kgCO2/m . background heating; underseat A quarter of all materials used in the building are recycled, including up to 76% recycled ÅV^OLYLHUK[OLPTWHJ[ heated air supply providing aggregate (using stent, a byproduct of the Cornish china clay industry) and 40% recycled cement extra heating and fresh air; and substitute (ground granulated blast furnace slag) in the concrete, 60% recycled content in the jetted heated air supply for quick interior blockwork, recycled glass in the wall insulation and recycled plastic for the seats. `V\JYLH[L^PSSOH]L[OL conditioning of the arena. In the summer and mid- season, the shape of the roof WV[LU[PHS[VILMLS[NSVIHSS` comes into its own, allowing the main arena to be fully naturally ventilated (there is no mechanical cooling in the main arena). The high-points of the roof are over the main seating Now that’s a career. areas, where the heat gain is greatest, so a chimney effect has been created by integrating With energy. outlet vents into the high points of the building façade, with inlet vents lower down. Leaving some of the concrete substructure exposed in critical places creates a thermal mass which helps to reduce heat build-up. The Velodrome is the centrepiece of a landscaped VeloPark which also includes the BMX track, and will later be joined The finished Velodrome has rainwater harvesting and low use fittings that reduce mains water demand by 75%. by a one-mile road cycle circuit A total of 5,500 m2 of Western Red Cedar timber was used for the cladding and 56 km of sustainably sourced Siberian pine timber was used for the cycle track. The structure involved the use of 28% recycled materials (WRAP) and 25% and mountain bike trails to create recycled aggregates © London 2012 a cycling legacy which will last for generations to come – however Ingenia would like to thank Rachel Thomas of +plus magazine for her original story on which this article is well the team based – see www.plus.maths.org and Hugh Ferguson for updating the online text performs in the Olympics. (UPU[LYUH[PVUHS See more articles on the There is an extra article on the temporary venues created for the Games at www.ingenia.org.uk LULYN`JVTWHU` Velodrome at http://tinyurl. It was written by Paul May, Head of Venue Development of the London Organising Committee for the com/cofbu73 Olympic and Paralympic Games and Steve Cardwell, lead project manager for London 2012 from Atkins ^P[OVWLYH[PVUZ

28 INGENIA ^VYSK^PKL