Gridiron Comes To Sydney

Macquarie Bank's new headquarters at King Street Wharf in Sydney's CBD is shaping up as a striking showcase for the design capabilities of XLERPLATE® steel.

The King Street Wharf development consists of two blocks, an 11 floor and seven floor building, each supported by an innovative grid like outer structure made from XLERPLATE® steel, called an external diagrid. The floor area of the buildings is spread over 35,000 square metres and consists of a central courtyard.

This project has set a new benchmark for steel construction in Australia, where until now only 13 per cent of multi storey buildings have been made from steel.

Developer Multiplex engaged BlueScope Lysaght's Design and Construction to provide the entire structural package, following an original design concept by Fitzpatrick and Partners. XLERPLATE® steel has played a critical role in the construction process, the fabrication of the external grid was a painstaking and labour intensive process.

"The logistics of the operation provided an immense challenge," BlueScope Lysaght's Design and Construction National Manager Brent Poll said. "This project involved 342 crosses in the external lattice, each one different, so the crosses had to be constructed individually, numbered, craned up and then fitted in that same order."

Southern Steel Distribution supplied Grade 400 and 450 XLERPLATE® steel to fabricate the lattice like grid structure, which consists of universal columns, buttwelded together to form the diagrid. Each section is six metres long and had to undergo ultrasonic testing to ensure it met structural requirements.

Grade 450 XLERPLATE® steel was chosen to reduce the weight of the structure. It was also the best steel solution to fit within the tight dimensions specified by the designer. Other advantages of using steel included speed of construction, and off site fabrication (which allowed for less on site labour).

Construction commenced in October 2007. The building's structure was completed in February this year, with internal fit out commencing in March. Macquarie Bank is expected to move into the building in early 2009.