Barron River Bridge reduced to one lane as ‘planning study’ continues

Commuters’ patience will be tested today as the 59-year-old Barron River Bridge at Kuranda is cut to one lane again. Read what’s in store for the beleaguered crossing next.

Tablelands commuters will have their patience tested again with the 59-year-old Barron River Bridge returning to a one-lane snail trail from today 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 Barron River Bridge has been studied by the Department of Transport and Main Roads since 2015 and will again be reduced to one lane. Picture: Brendan Radke

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 it.

In April 2021, Federal MP for Kennedy Bob Katter released reports obtained under Right to Information rules showing engineers made recommendations back in 2015.

In February 2020 TMR imposed a load limit of 50.5 tonnes.

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 span length for bridges of its era.

The commuter crawl as the Barron River Bridge is reduced to one lane in October 2021. Picture: Brian Cassey

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”.

It stated theoretical fatigue life had been reached at some vulnerable locations as a consequence of 60 years of trucks crossing the bridge, an increase in the mass of trucks by around 50 per cent since the bridge was designed, and fatigue-sensitive rails incorporated in the bridge.

“Targeted inspections subsequently identified fatigue cracks in some welds,” a TMR website stated.

“Brittle fracture is initiated when a combination of brittle steel, stress and cracks exceed a threshold.

Investigations into the Barron River Bridge at Kuranda, which was built in 1963, have been ongoing since 2015. Picture: Stewart McLean

“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 a detailed testing and monitoring program to ensure the bridge remains safe.

The $1.6m Cairns to Northern Tablelands Access Strategy, widely criticised by community leaders, recommended no major upgrade of Kuranda Range Road was needed before 2051.

The report, released in January, states the Kuranda Range Road will not reach capacity until 2051, based on a 1 per cent growth rate.

However, critics of the glossy booklet say the road is at capacity now and the report is a stalling tactic to conceal a lack of enthusiasm to bankroll a costly long-term solution.

Originally published as Barron River Bridge reduced to one lane as ‘planning study’ continues