Lift off for Molonglo River Bridge project

Spanning 200 metres across the Molonglo River, the bridge is being constructed using four heavy-duty steel girders. Each girder is made up of five segments – including abutment pieces, pier segments and midspan components – carefully designed and assembled to support the load requirements and 100-year design life of the structure. In total, the girders contribute to a staggering 2430 tonnes of Australian weathering steel, fabricated over the past year by Civmec at their Tomago facility in New South Wales.

Transporting the segments from Tomago to the Australian Capital Territory is no small feat. Each piece takes three days to make the journey, before being unloaded onsite using two large cranes – a 250-tonne Sani tele-crawler and a 275-tonne Sumitomo pin jib crawler – working together in a coordinated lift.

Self-propelled modular transporters – slow-moving vehicles designed to carry heavy loads – move the steel girder segments from unloading to temporary trestles. Once two segments are in place, workers bolt them together using 384 bolts per splice to form a single, secure piece ready for lifting onto the bridge.

To perform the lifts, BMD enlisted Australia’s largest crawler crane, the CC8800-1 Demag. With a lifting capacity of 1600 tonnes, the giant machinery was transported from Perth on 120 separate loads and carries 640 tonnes of counterweight on its super lift tray alone. Only two cranes of its kind operate in Australia.

The successful lift of the first girder segments marks a major achievement for this vital project, as explained by BMD General Manager NSW/ACT John Vida.

“In the coming weeks, our team will undertake eight precision lifts, a complex engineering task that also involves relocating the Demag crane to complete the southern span. These works are laying the foundation for a critical new transport link that will replace the flood-prone Coppins Crossing and improve safety and reliability for people moving between Canberra’s growing suburbs.”

“When our work here is done, the Molonglo River Bridge will stand out as a significant civil engineering achievement in the heart of the ACT. As we deliver the bridge and surrounding infrastructure, we’re also contributing to the region’s future by strengthening local capability, enabling upskilling opportunities, and leaving a legacy that extends well beyond the life of the project,” he said.

Temporary road closures and traffic impacts are expected during crane operations, and BMD is working closely with authorities to minimise disruptions while maintaining safety for road users throughout construction. Once complete, the Molonglo River Bridge will significantly improve safety and reliability for the region.