Tantangara adit with the TBM conveyor belt stacker in the foreground and the western boundary behind the adit face. Images courtesy of Snowy Hydro

Tunnelling has resumed at the Snowy 2.0 project’s Tantangara site following the approval of a planning modification by the New South Wales (NSW) government. The project faced a temporary halt due to soft ground conditions and the emergence of a sinkhole above the tunnel boring machine (TBM) Florence.

The restart saw TBM Florence making its initial advance last week, utilizing closed (slurry) mode for the slow and steady progress. The project has deployed specialized and experienced personnel to oversee the tunnelling process.

Dennis Barnes, CEO of Snowy Hydro, expressed satisfaction at reaching this milestone and emphasized the importance of the green light for the Tantangara tunnelling to recommence. 

“The conditions of approval were developed through the extensive review, public consultation and determination process, and will be strictly adhered to as we get back underway with excavation of the tunnel,” Barnes said. “The Snowy 2.0 delivery team is acutely aware of its responsibilities working in the sensitive environment of Kosciuszko National Park. We are focused on achieving excellent environmental outcomes throughout construction of this pumped-hydro expansion of the Snowy Scheme and critical infrastructure for Australia’s transition to renewable energy.”

The modification approval extends the project's western boundary above the TBM at Tantangara, allowing for close monitoring of surface conditions as TBM Florence advances. Surface monitoring will persist until there is at least 100m of overburden between the TBM and the surface.

Preparations for the restart included comprehensive geotechnical investigations along the headrace adit alignment and ground improvement works.

In parallel developments:

  • At Talbingo, the Snowy 2.0 project is making strides with the excavation of the tailrace tunnel. TBM Lady Eileen Hudson has covered approximately 1000m since its relaunch in July.
  • Manufacturing of the project's six pumped-hydro units, set to generate up to 2200MW of power for Australia's electricity grid, is in full swing. Notably, five of the six 153-tonne spiral cases have been manufactured, along with other major power station components, including the first turbine runner. One of the 13m-long, 7.5m-wide spiral cases recently completed a 442km night-time journey from Port Kembla to Lobs Hole in the Snowy Mountains.

Snowy 2.0 spiral cases and other components at the Voith Hydro Shanghai factory