The Square Kilometre Array (SKA) Africa project's radio antennae positioner took top honours at this year’s Southern African Institute of Steel Construction Steel Awards, which took place on Thursday night at Emperor’s Palace, in Ekurhuleni.

This year marked the second in a row that the overall winner also took first prize in the Association of Steel Tube and Pipe Manufacturers Tubular category.

The judges noted that the SKA project’s use of tubular steelwork for the 64 antennae that will be required “shows off the attributes of tubular construction and represents excellence in the use of tubular steelwork”.

The judges further highlighted that the geometrical complexity of the antennae competes with last year’s overall winner, the Malapa project, which, though complex, was built with the luxury of "normal" 2 mm structural tolerances.

They explained that the antennae positioner allows for a vertical tilt range of between 15° and 88°, and an azimuth range of 360° to an accuracy of within 1.4-thousandths of a degree under optimal conditions, and seven-thousandths of a degree during normal operational conditions.

“That’s a degree of accuracy that is hard to grasp for structural engineers, given the fact that we normally work to the nearest 2 mm,” they said.

Further, the largely tubular antennae support structure, was, by choice of the fabrication team, constructed with zero-tolerance targets. “The engineering, detailing, jig fabrication and construction put these structures into a different league from run-of-the-mill tubular truss-type projects,” they said, adding that the accuracy of dimensions after erection is critical to give the radio telescope “maximum chance of achieving its unimaginable expected accuracy”.

The judges concluded that a scientific project of this nature, which challenges the skills of South African engineers and scientists to rise above the challenges and to “make it work”, is especially a triumph in the use of steelwork and is “truly deserving” of being the overall winner of the 2015 Steel Awards.

Project-managed by satellite and communications products and services provider General Dynamics SATCOM Technologies, the SKA project is an international effort to build the world's largest radio telescope. When operational, it will provide astronomers with unprecedented detail, thousands of times faster than currently and to a resolution 50 times that of the Hubble space telescope.

Part of South Africa’s technical capability displayed in the bid for the SKA was supported by the design and build of the seven dishes for the SKA Africa telescope. This ‘mini-SKA’ has already delivered images of the galaxy Centaurus A, which is 13-million light years away.

The SKA Africa programme aims to complete the assembly of 64 antennae positioners by late 2016 – on a site 90 km from Carnarvon, in the Northern Cape and, thus, far from engineering resources – so that by mid-2017 the SKA will already be conducting scientific work.

Steel Awards 2015 was held simultaneously in Johannesburg, Cape Town and Durban.

Some of the other category winners included the air-cooled condenser at State-owned power utility Eskom’s Medupi power station in the Mining and Industrial category; JSE-listed Value Logistics’ Western Cape-based distribution centre in the B&T Steel Factory and Warehouse category; and the cladding work for Multichoice City, which took first prize in the Global Roofing Solutions Metal Cladding category.