Leaves the competition standing
On 20 and 21 October the first race of the year will take place at Kuala Lumpur's new Formula 1 Grand Prix circuit. The circuit has a dramatically placed grandstand in a finger of land jutting into its centre, offering views of straights on either side and a dramatic position against a hairpin at one end.
To take advantage of this, the 650m long grandstand has two multi-layered circular viewing platforms sitting within the hairpin, the most desirable spots of all, particularly for those who gain some pleasure from the mishaps of motor racing. The entire grandstand is, claims the client, the largest in the world and the only one to be double-fronted.
Engineers Modus and Sinclair Knight Merz worked with fabricator Westbury Tubular on the stadium, to realise the vision of architect Tilke for the fabric roof. Stephen Morley, design principal with Modus and Sinclair Knight Merz, is confident that the solution reflects the architect's vision while being achievable within the cost constraints typical of Malaysian projects. 'Design and build is often seen as a bad thing, as a compromise, ' Morley said. 'I like to think here that with Westbury Tubular and ourselves, we ended up with something very satisfactory.'
The original concept of the architect was for what it described as a series of banana leaves, but would actually have been more like a series of holly leaves. These faceted structures, with concavely curved edges, would join their neighbours at their points.Glazing would fill the interstices.The leaves would run perpendicular to the facade of the stadium, breaking up its tremendous length. Just as important, this would be a distinctive solution, an essential requirement for stadia. 'This is an area where nobody ever wants to do what has been done before, ' says Morley.'It has to be original.'As well as their primary function, stadia are often used to market a town, a region, even an entire country.
The engineers managed to fulfil both the architect's primary objectives, despite having to make some changes from the original. The first thing to go was the use of glazing between the leaves. 'The glazing was a casualty of technology and affordability, ' says Morley. Although the value of the canopy project was £7.5 million, this was modest considering its size.
The engineers looked at the possibility of using a translucent fabric to create a distinctive look, but the reduced number of fibres needed to achieve translucency also makes the fabric weaker.
Instead, the practice opted for inserting pieces of darker fabric between the 'leaves' to achieve the separation. The result is not only to break up the long line of the roof; it also provides a rich effect, like a slashed Elizabethan sleeve with some sumptuous stuff peeping through the cuts.
The supporting structure is ingenious rather than original.A variation on the structure used at Don Valley in Sheffield, it changes the size of the structural members, so that they are thicker at the base of the columns, and more slender at the top of the arches. The members consist of circular hollow sections with a plate attached, so it is only the dimensions of the plate that vary. The structure is suspended from masts that soar above the canopy.
The steel arch members act effectively like the stem of the leaf, joining into branches that go down into concrete columns which act as the trunks of the trees. Also forming part of these stems are the rainwater outlets which have to accommodate the heavy storms that can afflict Malaysia. This detail was relatively simple to resolve but a greater challenge came from the circular elements of the stand, where the canopy supports and the rainwater drainage come together with much larger bending moments to a single central point.
The fabric itself is a PVC polyester fabric which has a translucency of 15-20 per cent. It is coated with PVDF (polyvinylidene fluoride) which helps to keep it clean. Without this coating, the PVC dirt.
Morley, who spends his working life globetrotting, is impressed by the international nature of the project. The fundamental engineering was done in Sydney, the project was drawn in Kuala Lumpur, and the shop drawings were carried out in Kuala Lumpur. He is also pleased with the result but, asked if he believes this is a design that will be much imitated, says no.
'Next time somebody might modify the basic concept of fabric and arches again. This is a business where you try to create something unique every time.'
CLIENT Malaysian Airports Berhad
MAIN CONTRACTOR Ahmad Zaki Sdn Bhd: Murray & Roberts (Malaysia) and WCT Engineering Joint Venture
GRANDSTAND CANOPY STRUCTURE Westbury Tubular (Malaysia) and Sinclair Knight Merz (Australia) design-build team
CANOPY FABRIC Alom Industries (Sarawak)