02/04/2026
Swan River Crossings: Brady takes on the challenge of Australia’s first extradosed bridge
At Fremantle, in Western Australia, Brady Marine & Civil has contributed to one of the country’s most landmark infrastructure projects: the construction of the new Swan River bridge, Australia’s first ever extradosed structure.
An exceptional project
Commissioned by Laing O’Rourke on behalf of WA Main Roads as part of the Fremantle Bridge Alliance, the project aims to replace a timber bridge dating back to 1939 with a modern four-lane structure. Its extradosed design — combining both cantilevers and cable support — makes it a national first.
Brady was involved in the project from June 2024 to June 2025, under an Early Contractor Involvement (ECI) target cost contract, a collaborative approach that allowed us to bring our expertise into the project from the earliest design stages.
A technically demanding scope
Brady’s core mission focused on the design and delivery of temporary works and permanent bridge foundations, in a constrained marine environment.
Key achievements include:
- Temporary works: design, procurement and installation of four temporary steel jetties, totalling 1,200 tonnes of structural steelwork and spanning 240 linear metres. These platforms, capable of supporting 320t and 480t crawler cranes, were constructed from the riverbank without the use of barges or heavy marine equipment.
- Pile driving and drilling: installation of 45 temporary piles of 1,000mm diameter and 28 permanent steel piles of 1,500mm diameter, up to 60 metres in length, followed by internal drilling using a fly drill.
- Precast pile cap shells: placement of four 120-tonne precast concrete pile cap shells, sealed underwater to achieve a temporary watertight seal, before permanent welding to the steel piles.
Innovation at the heart of the solution
Due to site space constraints, the use of floating marine vessels was not possible. Brady developed a bespoke solution: piled temporary steel jetties, built from the riverbank, with no need for heavy marine equipment.
This approach offered several key advantages. Components were fabricated in sizes and weights suitable for transportation as standard loads, with no abnormal load movements required. All connections are bolted, allowing the structure to be dismantled and reused. The integrated steel deck is compatible with Self-Propelled Modular Transporter (SPMTs) and heavy load lowbed trailers.
Designed with the long term in mind: Brady’s teams will return to site in April 2026 to dismantle and remove all temporary works elements.
A project that showcases our expertise
This project demonstrates Brady Marine & Civil’s ability to deliver on complex structures in constrained environments, with an integrated approach spanning from temporary works design through to permanent foundation construction. It also highlights the value of early ECI involvement, enabling construction challenges to be anticipated and innovative solutions to be developed before works even begin.
ForSHORE: driving Soletanche Bachy’s maritime expertise
This project perfectly illustrates the momentum generated by the ForSHORE brand, which brings together all of Soletanche Bachy’s expertise and know-how in the field of maritime works.
