HB steel giant wins award for Waikato River arch

The steel archway formed by Napier company Eastbridge on the Cambridge Pipe Bridge. Photo / Supplied

A wastewater pipe bridge has become the latest award-winner for Napier structural steel contractor Eastbridge.

The company won the $1.5 million to $3 million project category at the Steel Construction New Zealand (SCNZ) Excellence in Steel Awards in Wellington on Friday, for its work on the Cambridge Pipe Bridge spanning 75 metres over the Waikato River.

Judges made special mention of the seamless completion of the project, upgrading services with previous infrastructure no longer able to meet the needs of a growing Cambridge community without disruption to the existing services.

The judges also noted a design aimed at minimising impact from such events as earthquakes.

The bridge uses a network arch design, an efficient and lightweight bridging form the judges said "looks slender and visually appealing".

Constructed off site, the new 75-tonne steel bridge took approximately 10 weeks to move into position, and and a skyline of five cranes, including a 400-tonne crawler crane, to assemble the steel network arch across the river.

An SCNZ statement said the innovative "floating" bridge foundations, constructed without piles, means the pipe services and the bridge remain flexible, and in an earthquake would "move and settle together", requiring minimal re-levelling to reinstate the critical sewer service post-event.

The judges were impressed by the elegant design and innovative solution for a piece of prosaic infrastructure, noting that it was a "really smart alternative solution that ticked all of the boxes – it was cost effective, seismicly resilient, sustainable and structurally adaptable".

With origins back to the 1960s but known as Eastbridge since 1996, the company has grown to employ about 120 people across two sites in the Napier industrial districts of Pandora and Onekawa, said general manager Andre van Heerden.

The Cambridge project is dwarfed by some of its other work, including the recent completion of work on two bridges in the new Transmission Gully State Highway 1 route in and out of Wellington, and its biggest-ever project, ongoing and involving two viaducts on the SH1 route around Tuhoi, north of Auckland — involving about 4000 tonnes of steel and costing about $14 million.