Engineering excellence recognition for Melbourne’s iconic Swan Street Bridge

Melbourne’s iconic Swan Street bridge has won the 2019 Victoria Civil Contractors Federation (CCF) Earth Awards Category 5 (Projects between $30-70 million value) on 16 August 2019.

Swan Street Bridge, Melbourne, Victoria. Photo: John Gollings AM

The Victorian Government/Seymour Whyte project was a complex endeavour and included the design and construction of the bridge which included incorporating a cantilevered four-metre shared user path on either side of the bridge with protruding tapered steel fins, while also retaining the aesthetics of the heritage structure.

The bridge works also included the demolition of the existing outer beams, then reinstating them with stronger precast beams; introducing a water sensitive urban design drainage system to treat bridge run-off; the relocation of a major gas pipeline.

“It is huge honour to receive the Victoria CCF Earth Award for Engineering Excellence,” said Courtney Hoops, Seymour Whyte Operations Manager, Victoria.

“Our team introduced an innovative solution that mitigated a number of challenges to widen both sides of the original bridge structure.”

“Seymour Whyte’s tender winning alternative design involved demolishing the existing outer beams entirely; and replacing them with stronger precast beams. Our solution minimised reliance on the older structure, facilitating a faster, smoother construction phase and providing an opportunity to substantially enhance the visual appearance of the critical connection between the steel fins and the new outer beams – enhancing the architectural outcomes that were essential on such an iconic structure”, he said.

“In doing so, we were also able to perform most of the works from barges located on the river, minimising the need for traffic management and further disruption to the traffic network.”

Seymour Whyte’s ‘Streamlining Hoddle Street’ Stage 1 Project near Melbourne’s Eastern Freeway was also a finalist for the same award.

Courtney Hoops said, “I’d also like to recognise our Hoddle Street Project, itself a very complex project. Given that the Swan Street Bridge and the Hoddle Street projects are Seymour Whyte’s second and third projects to be completed in Victoria, to be recognised in this way is a remarkable achievement for which our teams should be very proud.”

“Thank you to our client, VicRoads (now MRPV); and our team of dedicated staff and industry partners for their technical expertise, support and commitment to the successful delivery of these iconic projects for Melbourne.”

Swan Street Bridge Engineering Excellence
Swan Street Bridge provides a vital connection, linking Melbourne’s CBD with its world-renowned sporting and recreation precincts.

Spanning the Yarra River, the iconic bridge opened in 1952 during the infrastructure surge leading up to the 1956 Melbourne Olympics. Sandwiched in its highly visible and constrained site, the bridge provides access to and from the city centre for upwards of 30,000 vehicles each day; a volume that was creating unsustainable bottlenecks. A desire for faster commute times, together with improved safety for vehicles, cyclists and pedestrians, were the key drivers for the necessary upgrade of the aging structure.

The concept design required the strengthening the existing beams and soffits for the construction of a new 300mm deck overlay on the existing bridge. The height of the overlay also necessitated that the existing abutment and surrounding infrastructure be raised to tie into the new levels.

In our alternative design, the new deck levels differed only marginally from the existing levels, thus removing requirement to strengthen existing beams, and significantly reducing the difficulty and volume of tie-in works for the abutments and surrounding infrastructure. Maintaining existing pavement levels either side of the bridge reduced the load on underlying silty geological conditions, and simplified the management of ongoing settlement in the design.

During the design phase, Seymour Whyte presented the innovative idea to demolish the existing outer beams, then reinstating them with stronger precast beams as well as designing bespoke connections for the steel fins, deviating from the proposed welding methodology in the concept design.

The alternative ‘keyed’ connection not only vastly enhanced safety by eliminating high-risk welding over water, it also reduced the installation time for each fin to just minutes.

Now complete, the upgraded Swan Street Bridge is wider, safer and more durable than ever enhancing the user experience. The finished structure is a visual success. Boldly accented by LED lighting and boasting just the right balance of arcs and angles.

The project has demonstrated that it’s feasible to upgrade and enhance ageing bridge infrastructure, as an alternative to building something new and demonstrates our capability to build complex projects through innovation and strong partnerships with our project stakeholders.

Seymour Whyte Project Manager Tom Yates said, “The project is a testament to what can be achieved through the engagement and alignment of the team – including the client, contractor and subcontractors all working together to overcome a number of complex unexpected issues collaboratively.”

“Ultimately, we have produced an end product in an extremely challenging environment, that will be there for years to come, that the whole team can be proud of.”

“On challenging projects, people may sometimes become only too keen to put the project behind them and forget about it. This project has produced something special, and I’m sure all of us involved will walk over the bridge and surrounding area for years to come and be proud to identify ourselves as being part of its creation.”