A source close to the Snowy 2.0 project believes issues with tunnel boring machine Monica, the project’s fourth TBM, raises serious questions about the machine’s performance.

The source told the Monaro Media Group they believe TBM Monica has experienced multiple issues with its screw conveyors since it was launched earlier this year. The problems the source said have led to unplanned maintenance stops and raise concerns about the TBM before it heads into the tough geographical terrain of the Long Plain fault zone.

“When the TBM gets into the Long Plain fault zone, due to the highly fractured ground, it has to advance continuously and can’t stop,” the source said.

“Hence, the machine has two screw conveyors, so when one is stopped for maintenance the other one is supposed to operate.”

TBM Monica was acquired for around $75 million as the project’s fourth TBM, in efforts to ensure the delivery of the nation’s largest committed renewable energy project.

When asked by this masthead if TBM Monica has experienced any issues with its screw conveyor or if Snowy Hydro has any concerns over the TBM’s performance, the company issued the following response.

“TBM Monica has been designed specifically to tackle the Long Plain fault zone,” a Snowy Hydro spokesperson said.

“Maintenance stops are important to ensure the TBM is set up for maximum performance and reliability as it approaches the complex geology of the fault zone.”