By rosebell
In order to digging the portion of the 17km headrace tunnel that passes through the geologically challenging 850m Long Plain Fault Zone, the 12m-diameter TBM, named Monica, is due to be commissioned from the Marica worksite, near Kiandra, in the coming weeks.
Considering the challenging conditions the tunnel excavation required an additional machine, while it originally was to be completed solely by TBM Florence.
TBM Monica was named after Monica Brimmer, a Tumut High School student and winner of a First Nations art and storytelling competition. Attended by climate change and energy minister Chris Bowen, the on-site commissioning ceremony was done and Monica radioed in instructions for the cutterhead’s first rotation.
While the advance is being made across the project’s four worksites in the NSW Snowy Mountains, around 1km underground at the project’s Lobs Hole worksite, construction work is shifting from tunneling and excavation to preparing the fitout of a complex underground power plant the size of Sydney Opera House.
The number of completed permanent concrete pours in preparation phase is 46 so far and over than 733,000m3 of underground material has been excavated. Also using some techniques that were pioneered on the original Snowy Scheme; and drill-and-blast method the large subterranean caverns have been created.
Benefiting 450m3 of concrete, 160m2 of formwork 3.7m thick, as well as 80 tonnes of steel reinforcement, at Tantangara, principal Future Generation JV has completed the crown of the tunnel transition at the entrance to Snowy 2.0’s intake structure.
