One of the two tunnel boring machines (TBM) being used to create the new Perth Airport rail link has been temporarily shut down for more than a month after a number of “ground disturbances” were detected during the project.
TBM Grace was one of two machines which began boring out an eight kilometre long tunnel for the Forrestfield-Airport Link project in July last year.
On Monday a Perth Airport spokeswoman confirmed TBM Grace had been halted “due to some ground disturbance issues”.
The Public Transport Authority (PTA) confirmed the decision to stop TBM Grace had been taken on February 14, and it was waiting for international experts to return their report on the situation before resuming work.
When pressed, authorities including Premier Mark McGowan and Transport Minister Rita Saffioti would not clarify what type of “ground disturbance” issues had been detected in the project.
“Tunnelling work by TBM Grace for the Forrestfield-Airport Link — which has not yet reached any critical infrastructure — has been temporarily suspended,” the airport spokeswoman said.
“There has been no threat to public or worker safety.”
The two “disturbances” occurred on Perth Airport land, and the head contractor made the decision to stop the machine after discussions with Perth Airport and the Public Transport Authority.
A PTA spokesman said the nature of the terrain was always expected to present challenges to the project, but the PTA remained confident there would be no delays.
Mr McGowan said he had not received advice to say there had been any risk to the public or that the ground disturbances were “serious”.
“Whenever you do a major construction contract things happen but obviously, obviously we are not going to compromise anyone’s safety at the airport,” he said.
“We’re not going to take any risks. We’ll take the best advice in relation to these issues.”
Despite the machine sitting idle for almost five weeks, Mr McGowan said the timeframe for the project was not being disturbed because the tunnelling was ahead of schedule.