By Max Maddison
Construction on the $3.1 billion M6 stage one motorway will be paused indefinitely after hundreds of tunnel workers were ordered to stop work in a dramatic escalation of the dispute between the government and its contractor, throwing the already three-year-delayed project into disarray.
Thirteen months after two large sinkholes emerged at Rockdale, pausing work on the 244-metre section of the tunnel, contractor CGU – a joint venture between construction companies CPB and Ghella, and engineering firm UGL – has suspended all below-ground work on the project from Anzac Day.
M6 stage one construction alongside President Avenue, Rockdale, in Sydney.Credit: Janie Barrett
The pause compounds the project’s existing woes. The sinkholes, including one 10 metres wide, have pushed the project’s completion to 2028 – three years later than initially planned, Transport for NSW has stated.
A geotechnical report obtained by Transport for NSW (TfNSW) laid blame for the sinkholes with the construction of the tunnel, leaving liability for the remediation with CGU. But, with neither party willing to yield, the contractor has taken the extreme step of pausing work indefinitely.
Work on the affected area, estimated to be around 10 per cent of the project, has been on pause since March last year. However, the fresh pause will impact all work taking place below ground, affecting up to 400 workers, a source not authorised to speak publicly said.
Surface work along President Avenue will continue as planned.
Transport for NSW acting deputy secretary Glen Mace said it had been advised CGU intended to defer “some work” and was working to “understand this approach and the potential impacts on the overall project”, including the 2028 delivery time.
“This is an independent commercial decision … to manage their costs,” Mace said. “Transport remains committed to this critical project and will work through the technical and commercial issues raised by [the joint venture].”
“Elements of tunnelling have been suspended after subsidence occurred to ensure safety and enable redesign work. Transport has sought a revised design from the [joint venture]. There is ongoing dialogue between the department and the [joint venture] on all aspects of design, operations and safety.”
Roads Minister Jenny Aitchison said: “The NSW government’s priority remains working towards delivering this project safely and in-line with the 2028 timeline.”
Lead contractor CPB declined to comment.
An April 15 email from the joint venture’s project director to staff acknowledged there had been “some significant challenges to date” with sinkholes, soft ground and geological issues and discussions between the parties had so far been unsuccessful.
“Despite all efforts, we have not been able to agree with TfNSW on some key issues,” the project director wrote.
“In accordance with our contractual obligations, and having notified TfNSW, we have made the difficult decision to resequence certain non-time-critical delivery activities in order to mitigate impacts to the project.
“We remain committed to engaging with TfNSW to resolve these issues and are hopeful that things will improve in the future.”
The email outlined a number of activities that would be paused “from May”, including tunnel excavations, mechanical and electrical activities in tunnels. Other activities, including roadworks, quality assurance for completed works and designers on site, would continue.
However, contractors had been told all below-ground work will stop and be decommissioned after Anzac Day, while work at street level would continue until August.
Government sources said CGU’s decision to down tools needed to be seen in light of the ongoing negotiations.
Workers have not been provided with a resumption date. Many were concerned the protracted dispute could lead to widespread redundancies, with little other tunnelling work available.
The M6 stage one has been plagued by problems. In March, the Herald revealed 13 tunnelling workers, including a 32-year-old, who worked on the site had been diagnosed with silicosis, an incurable lung disease.
Regulator SafeWork NSW has begun an investigation into the workers’ firm, CPB.
Opposition transport spokeswoman Natalie Ward said: “With more information to come, it is disappointing if this leaves Sydney with fewer jobs and an unfinished tunnel that taxpayers have already invested significantly in.”
In February, TfNSW deputy secretary Camilla Drover could not provide an estimated cost for the delays to the M6, saying the department was still in discussions with the contractor about required works and “who bears those costs”.
Drover said there had been a redesign of the section of tunnel affected by the sinkholes, and tunnelling on the areas affected would restart by the end of 2025. In September, she said 86 per cent of the tunnelling for the entire M6 project was complete.
“We’re targeting opening the full project to traffic by the end of 2028. The balance of the project is still progressing well, but of course, we can’t open the full motorway tunnel until we’ve obviously finished tunnelling it out in the subsidence area,” she said.
Motorists using West Botany Street near Bicentennial Park, an arterial roadway near the main sinkhole, will face slower journey times for 18 months when the road’s southern section is reduced to one lane while ground stabilisation works are carried out.
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