Snowy Hydro says high-pressure water jetting continues to be used to remove rock impinging on the shield of Snowy 2.0 TBM Florence at Tantangara, New South Wales.
The TBM was halted by the project team in extremely hard and abrasive rock conditions on May 16, and specialist contractors started work on May 21 to try to free the machine.
“The high-pressure water jetting technique to remove the rock is ongoing and working well,” Snowy Hydro said in a statement.
“We expect highly variable ground conditions to continue ahead of TBM Florence in the headrace tunnel.”
Prior to the TBM stopping, Snowy Hydro had said Florence had been ramping up excavating the headrace tunnel, advancing 12m per day.
This is the second time the TBM has been stopped on the Australian pumped hydro project. In December 2022, excavation of the headrace tunnel was halted after a surface depression developed while the machine was transitioning from soft material into harder rock conditions. TBM Florence restarted in December 2023 following ground stabilisation works.
Snowy 2.0 is Australia’s largest renewable energy project. It will link Tantangara Reservoir with Talbingo Reservoir through 27km of tunnels and a power station with pumping capabilities.
Water jetting device mounted on the TBM cutterhead, with the machine’s shield on the left of the image and the rock on the right. The device directs a high-pressure water stream at the rock, causing the rock to break apart
