Berry to Bomaderry stretch of the Princes Highway, New South Wales, Australia

A 10.6km stretch of the Princes Highway on the NSW South Coast has recently enjoyed a $450 million upgrade.

In Australia, the Berry to Bomaderry stretch of the Princes Highway on the NSW South Coast has seen two bridges constructed featuring long span trough girders manufactured from BlueScope’s REDCOR® weathering steel.

This newly upgraded, four-lane section of road runs between Mullers Lane in Berry, and the Cambewarra Road roundabout in Bomaderry, and includes two composite bridges constructed using weathering steel (with concrete decks). The bridges are Strongs Road, Jaspers Brush which is a 55m long single-span bridge, and Pestells Lane, Meroo Meadow which is a 100m total span length (30+40+30), three-span bridge.

Transport for NSW needed a solution that delivered rapid construction – particularly prompt erection, and engineering flexibility – for complex geometries, and to support long spans which can efficiently be achieved with steel girders. The client also required that the proposed solution needed to achieve a maximum design life, with minimal environmental impact to the area, and minimal ongoing maintenance costs.

Project team: 

The value weathering steel can offer for bridge design internationally is echoed in the learnings from the NSW South Coast Princes Highway upgrades including key benefits in the constructability and maintenance solutions offered using BlueScope’s REDCOR® weathering steel.

Success in the Princes Highway Upgrade

The Berry to Bomaderry upgrade of the Princes Highway demonstrates just how important the material selection is in the design stages of a project. Transport for NSW were able to deliver a successful project through consideration of REDCOR® weathering steel and research of the steel supply chain capability through to specification of REDCOR® weathering steel.

Overall the design delivered longer spans and a lighter structure providing savings in foundation and substructure costs. The steel was pre-fabricated off-site in a controlled environment resulting in safety benefits. Importantly the specification of REDCOR® weathering steel provided a critical advantage in significant whole-of-life cost savings with its 100 year design life capability, periodic inspection and cleaning should be the only maintenance required.

“This is the first time Transport for NSW has used weathering steel for a road bridge. I would be recommending its use in future projects. A weathering steel solution provides continuous network operation and overcomes the need for expensive routine paint work”. – Kumar Ponnampalam, Senior Bridge Engineer, Transport for NSW

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Designing bridges with weathering steel
Weathering steel has been used in bridge construction since the 1930s; it has been used extensively in North America, Europe and Japan for over 55 years and over the last 10 years in New Zealand.

Throughout the world, weathering steel has been widely adopted for bridges. It is estimated that up to 45% of steel bridges globally are constructed utilising some form of weathering steel.

Notable international projects include the Bay Gateway Bridge in the United Kingdom (that connects Heysham to the M6 in Lancashire) which opened in 20162, and in New Zealand where its use in the Karapiro Gully Viaduct (part of the Waikato Expressway) is projected to deliver a design life of over 100 years.


Images: BlueScope / Seymour Whyte | Full case study