Margaret Court Arena

Margaret Court Arena is the latest addition to a precinct giddy with expansion. A joint venture design by NH Architecture and Populous, the project is an arresting variation from the polite, white modernity of over-arching steel tubing, tensioned columns and Miesian planes.

Key to this is a high-speed 'sun-roof' for the $183 million project that offers premium seating for 7500 spectators. The roof made from COLORBOND® steel in LYSAGHT KLIP-LOK 700 HI-STRENGTH® profile, is swathed in the luxurious custom colour Copper Penny™* in a Metallic finish to the last centimetre and is a signature element of the project.

While many rooftops are the repository of cluttered mechanical services, the 57m x 64m operable rooftop here handsomely caps a sleek entity. NH Architecture’s project team leader Wilko Doehring describes the high-speed roof – capable of opening or closing in less than five minutes – as “a Lamborghini”. Such speeds make the once wunderkind roof of Rod Laver Arena (25 minutes) appear sluggish.

But the new facility and its roof are much more than purely about speed. The project underwent an intensive weight-loss program from its conception and the result is a spectacularly slender sheath of metal barely one metre deep. Doehring says the design goal was to produce the most elegant, lightweight and streamlined solution. He explains how the engineering, fabrication and construction teams worked tirelessly to produce a roof barely half the height of a man or woman.

"It very much reflects this age and takes a micro view of the world, of incredible miniaturisation and slenderness not previously possible," Doehring says.

In engineering terms, the project's crowning glory is equivalent to an ultra-strong lily-pad. "Fold a piece of paper and it becomes stronger," he says. "That is essentially what we did with the COLORBOND® steel LYSAGHT KLIP-LOK 700 HI-STRENGTH® material used for the roof to provide a substantially stiffened, strengthened span."

Slenderising this roof by the elimination of the usual roof tracking system introduced one of the major engineering headaches. The answer came in the form of inline wheels integrated with the roof edges to help reduce its profile from 'hamburger' to 'sandwich'. Despite being unable to track with such precision, Aurecon structural engineer Mark Sheldon says they managed to streamline the forces and overcome the tendency for excessive roof flex, potentially causing one inline wheel set to shift minutely out of alignment.

Despite the instability of single-rail bogies, Sheldon says the Aurecon team managed to develop a system whereby the bogies and roof steelwork supported each other.

Combined, they needed to allow small rotations for humps in the rails and any non-parallel or rail misalignments, yet allow the roof to slide over the bogey during skewing, or thermal movements.

"Its complexity wasn't helped by the interface between the structure and pleated skin that could potentially foul," Sheldon adds. "As much as we want to keep everything in perfect alignment, we can't. Temperature changes and construction tolerances, for instance, also alter dimensions and alignment of the two roof planes that meet above centre court. Each of the leading edge trusses span some 50m and sit 17.5m above the playing surface."

From a structural viewpoint, the architects and engineers inverted and contained most of the gymnastics within the structure. The new superstructure also resulted in a reduced overall height of 4.6 metres for the steel structure – incorporating XLERPLATE® steel manufactured by BlueScope – much lower than Rod Laver Arena and providing a degree of intimacy with scale, without any sense of claustrophobia.

Whether this stunning roof is open or closed, and regardless of the spectacle taking place inside, Margaret Court Arena reminds us that architecture and engineering are much more than mere construction: they have the power to generate a convincing spark and become part of a song-line for the city.

*Copper Penny™ is a COLORBOND® steel Custom colour subject to enquiry.