Bridge not up to speed
Study creating delays on Kuranda crossing
TABLELANDS commuters will have their patience tested again with the 59-year-old Barron River Bridge returning to a one-lane snail trail from Thursday as a result of an ongoing planning study.
A TMR spokesman said from November 20-27, there would be intermittent full closures of up to 10 minutes.
“We are undertaking a planning study to investigate long-term solutions for the Barron River Bridge near Kuranda,” he said.
The study was originally expected to be completed in late 2022, but will now conclude in early 2023, and will then progress to a business case.
“The business case will investigate the preferred options in more detail, including estimated costs,” he said.
“Drivers can be assured the bridge remains safe.”
The bridge was cut to one lane from January to March this year, and for 12 months from November 2020 to October 2021 as TMR investigated. In April 2021, Federal MP for Kennedy Bob Katter released reports obtained under Right to Information rules showing engineers made recommendations back in 2015.
The documents released by Mr Katter revealed the bridge, (built in 1963) was always going to be more susceptible to damage from heavier loads because it contained 45.7m spans – which were more than three times longer than the average for bridges of its era.
The documents revealed that retrofitted Macalloy bars – designed at increasing structural strength were “compromised through both pitting corrosion and wear of the stressing bars vibrating against the girders raising concerns of brittle failure in the bars”.
TMR information reveals structural assessments in 2020 identified locations of the 257m-long bridge “that were vulnerable to fatigue cracking, mainly associated with welds in steel girders”.
“Targeted inspections subsequently identified fatigue cracks in some welds,” the TMR stated.
“Brittle fracture is initiated when a combination of brittle steel, stress and cracks exceed a threshold.
“If cracks and loading on the bridge were left unmanaged, and a brittle fracture were to occur in a bridge girder, the chain of events that could follow is difficult to predict but could lead to the partial collapse or the collapse of a segment of the bridge.”
In March 2021, TMR announced the $2.1m planning project to assess options for rehabilitating and strengthening or replacing the bridge.
This week’s closure is part of that ongoing study.
The $1.6m Cairns to Northern Tablelands Access Strategy recommended no major upgrade of Kuranda Range Road was needed before 2051. The report states the Kuranda Range Road will not reach capacity until 2051, based on a 1 per cent growth rate.