Wednesday, February 16, 2011

Velodrome, by Hopkins

The London 2012 cycling venue is the first to be completed at the Olympic Park, and it sets a high standard for its fellow sports facilities to reach.
Long-imagined in our collective consciousness, a vision constructed from glossy renderings and chirruping, animated fly-throughs, the Olympic Park is finally beginning to take shape. What once seemed a barely feasible image, brazenly Photoshopped across the side of an 11-mile fence in east London, is now nearing reality. A horizon of cranes has given way to a prospect of jaunty rooftops, their profiles variously pitching, swooping or squaring up as blank, uncompromising sheds. After five years of waiting, watching a complex choreography of JCBs through strategically gouged gaps in the plywood hoarding, the results are there to be seen: a collection of vast sporting vessels has somehow been magicked from the churning sea of mud. And it is a compelling sight.
As our minibus creaks though double-height wire mesh gates, ominously capped with “electric topping,” having already passed through two security checkpoints, it feels eerily like entering an architectural Jurassic Park. To the south, looking like a manta ray kept afloat with arm-bands, glowers Zaha Hadid’s Aquatics Centre; on an island at the heart of the park soars the majestic exoskeleton of the main stadium; along the western edge lies the boxy trio of John McAslan’s Energy CentreMake’s Handball Arena and Allies & Morrison’s Media Centre, gargantuan containers clad in variously brooding clothing.
To the east looms the Athletes’ Village, with the stony cliff face of an Eastern Bloc housing project, next to the inflated cream cake of Wilkinson Eyre’s Basketball Arena. It is a motley assemblage of object buildings, each a slightly awkward offspring of its original competition incarnation, together forming a disparate but intriguing whole.
In between, much is still mud. But there are the beginnings of what will eventually become Queen Elizabeth Olympic Park: fledgling strips of turf with benches and trees, sloping down to the perfectly sterile banks of the new-look River Lea. It is an unearthly funscape somewhere between Teletubbyland and the manicured verge of a business park.
Olympic Park site plan
Olympic Park site plan
Rising above all this, as if aloof on its own mound to the north, floats Hopkins’ Velodrome. A slightly oval timber bowl, flaring up along its longer northern and southern flanks, and sinking down along its eastern and western sides, it sits on a continuous glazed ring, surrounded by a soon-to-be-planted berm. From across the park, with its steeply raked hull and long, low-lying gait, it is strongly reminiscent of Hans Hollein’s famous 1964 collage of an aircraft carrier rising out of rolling fields. Its double-curved roofline – at once nicknamed the Pringle or bent bicycle wheel – appears to hover above the plateau with effortless grace, a quietly monumental presence in the landscape. It stands out as one of the simplest yet most powerful forms in this strange steroidal zoo.
But it is a matter of serendipity that it exists at all – and a matter of political will that its design has, in Olympic terms, been relatively uncompromised. Cycling enthusiasts will be thankful, for theirs is one of the few sports blessed with a permanent venue in the legacy plan of the London 2012 Austerity Games, originally won on the strict premise that no new venues would be built unless there was an identifiable need for the facilities after the games.
Not only is there enormous political will behind cycling – with the flurry of “Boris bikes” and “cycle superhighways” appearing across London, along with the fact that, after Beijing’s medal hoard, we’re apparently quite good at it – but an East End cycling institution had been on this very site for the past 30 years. The forced demolition of the aging Eastway Cycle Circuit, which had survived happily nestled between a caravan park and a mountain of fridges since 1975, had the Lycra lobby up in arms.
And what a vociferously vocal lobby they are, for the physical result of their campaigning now stands before us: the £105 million Velopark, whose permanent legacy package includes a BMX track, a 6km mountain bike trail and a 1 mile road racing circuit – and, of course, the 6,000-seat, £90 million Velodrome.
Veldrome track
Source: Richard Davies
Veldrome track
“I can’t wait to come back in 2013,” grins a breathless cyclist, fresh off a test-run around the track, barely believing his luck that this new facility will be his to use following the games. “The spaces at Manchester and Newport are good, but this is something else.” He has good reason to be pleased: of all the venues, the Velodrome is the one that will change the least between its games and legacy modes, retaining all 6,000 seats with only slight modifications to entrance sequences and the functions of ancillary spaces. Unlike its poor aquatic neighbour, which suffered several redesigns as costs ballooned and legacy plans tightened – and is sporting temporary bulky seating wings as a result – the Velodrome will remain intact.
“We see the games as a two-week party,” says Hopkins director and project architect, Mike Taylor. “It’s a bit like a housewarming.” Without the need to accommodate complex temporary structures, clip-on components and changing programmes, he makes the design process sound relatively straightforward.
“The bicycle is a model of efficiency,” he enthuses, as we stand inside the track watching streamlined flashes of blue Lycra and carbon fibre glide past. “We designed the building to be like a bicycle – not formally, as in Beijing’s wheel-like velodrome, but in the spirit of its engineering.”
He describes how the envelope has essentially been “shrink-wrapped” around the track, seating bowl and sight lines, with nothing going to waste: “It is a taut structure, with everything at its absolute minimum – just like a bike.”
For such an approach, it was essential to work as an integrated design team from the beginning, with Expedition Engineering and contractor ISG. As Sunand Prasad, one of the judges on the original design competition, said, with the finesse of an RIBA mantra, they were looking for a “winning team not a winning scheme”.
World champion cyclist Chris Hoy was also on the jury, and his comments are clearly evident in the completed project. He complained of the “wall of silence” you experience as you ride around the bend, due to the usual lack of seating at these steeper ends, and the problem of draughts lowering the temperature when people come in and out. The architect responded with continuous seating all the way around the track, squeezing in three rows at either bend, as well as heated air curtains in the airlocked lobbies to maintain the track temperature at 26°C. Hoy’s more prosaic requests – such as having a toilet near the track, apparently a rarity – were also accounted for.

Velodrome cross section
Velodrome cross section
But the architectural ambition is much grander. Taylor, himself a keen cyclist, talks of how the form of the building reflects “the dynamism and geometry of the track,” and “exudes the drama of the race”. And, for once, the clichés are true. They have taken the shape of the track, turned it by 90 degrees and exaggerated its flaring geometry so it dips down as the track swells up to bank, and rises up into the gods along the straights. The outer facade is clad in Canadian red cedar, which will weather to silvery grey, wrapping all the way around and curving into the building to form a seamless soffit – a detail the architect fought strongly to keep in the design-and-build contract.
This form floats like an enormous wooden fruit bowl above the grassy berm, which takes you up 4m, via an assortment of steps and ramps, to a fully glazed public concourse level – the entrance during events mode. Entering halfway up not only speeds up access, but provides panoramic views across the park, from the distant slab of the Media Centre, to the neighbouring ventilation mound, civilised ODA-style with a piece of public art – in this case a lurid colour-changing fence by Carsten Nicolai. At the other side of the concourse lies the BMX track, giving glimpses of flying bikes through the window, lined up to make the Velodrome’s soaring façade the backdrop for their televised stunts.
From this podium level, the seating has been cleverly split in two, with 3,000 seats directly around the track – where its timber hull overshoots to form a balustrade, giving a sense of immense proximity to the riders – and the remaining 3,000 raised up above in the roof. By dividing the seating, the idea is that the Velodrome will never seem echoingly empty, even at low capacity events.
Above the concourse, 48 steel trusses are arranged radially on concrete piers, linked to form a 130m-diameter monocoque structure, on which precast concrete elements hold the raked banks of seating. At the top, the trusses connect to what Taylor describes as a double “roller coaster ring beam” that dips and rises 12m along its undulating course, from which the cable net roof hangs. The 36mm-diameter cables, from Austrian contractor Pfeiffer, were laid out on the ground like the strings of a tennis racquet, with specially designed nodes then fixed at their intersections, and the whole thing raised up and tensioned into place from the ring beam. Individual timber roof cassettes, manufactured by Wood Newton in Nottinghamshire, were then craned into place and each fixed with one bolt to allow for movement, leaving longitudinal strips for the 2m-wide roof lights – the generous amount of natural daylight being another key part of the design. Heavily insulated, the whole thing was then covered in a standing seam Kalzip roof. All told, this structure used only 100 tonnes of steel – in comparison to the Aquatics Centre’s 3,000 tonnes to cover a similar area – and required minimal temporary works, unlike its neighbour’s forest of scaffolding.
Standing at the dizzying heights of the upper rows of seating, the wires, bolts and spigots of this high-tensile assembly are exposed for all to see, although the world of service ducts is partially baffled by expanses of stretched white webbing, which looks a little like muslin added hastily to hide the backstage workings. The steep angle of the ceiling, which dips 8m across its width and rises 4m along its length, means that your view is effectively blinkered downwards, focusing attention on the action below.
Down at ground level, the back of house has been equally carefully thought through, with multiple circulation routes segregating dirty cyclists from clean ones, Olympic Family from hoi polloi, and providing offices with a view out on to the finish line of the road track. A gabion retaining wall lines an exterior route underneath the public concourse, leading into changing rooms and a circulation passage that, with its exposed structure of the seating above, feels not unlike the hypogeum beneath a Roman amphitheatre, with lion’s cage and bear pit exchanged for doping room and warm-up gym.
While the budgets for building such monolithic imperial structures went with the ancients, the Velodrome shows all the signs of leaving an equally convincing legacy – if not such a long one.
As a diagram of lean engineering and integrated design, it is a model for venues of its type, and has come out of the compromised quagmire of Olympic bureaucracy relatively unscathed. As the first completed sports facility on the site, it sets the bar high for neighbouring venues.