The Preston River Bridge Now Has Beams!
The Preston River bridge on the Willinge Drive extension, as part of the Bunbury Outer Ring Road (BORR) project, has reached its next milestone with the beams now installed and in place. But what does it take to get super-long bridge beams craned into place over a river?
Published: 09 July 2024, Updated: 09 July 2024
With the piles for the bridge adjacent to Preston River already bored into the ground, the bridge beam installation was next. The four bridge beams required for the bridge measured 44 metres, which is the longest beam length on the project. Despite this, each beam weighed ‘only’ 185 tonnes making them some of the lighter beams on BORR.
To lift the beams into place, an LG-1750-tonne crane with a super lift attachment was used. This crane features what is called a lattice boom. The internal lattice structure of the crane’s boom gives it superior strength and stability, even when lifting heavy beams high into the air and far out over a river.
At the Preston River site, a 42-metre lift-and-install radius was required due to the restrictions around getting too close to the abutment pile caps. These are the structural elements used to help distribute the load from the bridge’s superstructure down to the piles, deeply embedded in the ground below.
The significant size of this radius necessitated the type and size of crane to reach the bridge span.
During the bridge beam installation itself, the crane utilised 530 tonnes of counterweights, with 170 tonnes directly on the crane and an additional 360 tonnes on the super-lift tray. This was to ensure stability and enable precise positioning of the beams.
The LG-1750-ton crane
Site of the Preston River bridge prior to beam installation
Beam installation in progress at Preston River
Page last reviewed: | Last updated: