September's big wet delays temporary railway overpass bridge at Wallendbeen

It’s a race against time and tide as delays impede the construction of a temporary railway overpass bridge on Burley Griffin Way, at Wallendbeen, that was initially set to reopen in September 2021.

As the calendar ticked over to October, a recent dumping of 20mm of rain at nearby Cootamundra has mounted pressure with an impending harvest in the region.

A total of 69.8mm of rainfall in September was well above the district average of 50.6mm for the month.

Precipitation has been the bane of the railway bridge project. The replacement crossing was required after the existing 100-year-old rail overpass bridge was damaged by heavy rain earlier in 2021, requiring immediate demolition.

This resulted in Burley Griffin Way – a vital transport link to the Hume Highway – being closed to all traffic between Olympic Highway at Wallendbeen and Milvale Road at Temora since March.

It has also impacted passenger and freight rail services on the Main Southern Line between Sydney and Albury, and onwards to Melbourne.

Work started on construction of the temporary bridge in June, in what has been described as a carefully choreographed engineering challenge requiring the connection of modular, pre-engineered steel parts onsite.

The temporary bridge had to be transported from Sydney to Wallendbeen in 210 pieces for assembly by 20 workers on a gravel hardstand next to the site.

“Once this is done, a 650-tonne crane will lift the completed bridge into place across the rail corridor,” said Member for Cootamundra Steph Cooke.

This final stage will need to be completed in a timeframe of only four hours to avoid disrupting train services running on the rail line below.

The crane will be positioned on a large concrete slab and will lift the bridge onto the supports, allowing the construction of the road approaches to the bridge.

Once complete, a 30-metre-long, four-metre-wide, single-lane structure suitable for all vehicles, including PBS (2B) road trains, will extend over the rail line.

Ms Cooke has kept a close eye on developments and she likens the project to a giant Meccano set, with all the pieces snapped together for a perfect fit.

A 62-tonne piling rig drove in steel in-ground supports for the placement of the 210-piece temporary bridge, but prolonged wet weather and soft ground has delayed this work.

Ms Cooke said the less-than-ideal conditions required an additional steel support structure to be manufactured and installed.

As a consequence, the new temporary bridge is expected to open to traffic one month past its due date, in late October, weather permitting.

“We understand the significant impact the 40-minute detour is having on the community, motorists and freight operators, however this additional structure will ensure the crossing is safe,” said Ms Cooke.

During work, Burley Griffin Way will remain closed at the railway line.

Motorists should continue to use the detour via Olympic Highway and Goldfields Way during this time.

Motorists are advised to drive to the conditions, follow the directions of signs and traffic control, and allow up to five minutes’ extra travel time while work is underway.