Tunnelling of the Snowy 2.0 headrace adit at Tantangara has restarted after a delay caused by soft ground conditions and the emergence of a sinkhole above TBM Florence.  

The NSW government approved for the project’s planning modification. 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.The modification approval extends the project’s western boundary above the TBM at Tantangara. This will enable close monitoring of surface conditions as TBM Florence advances. Surface monitoring will continue until there is at least 100 metres of overburden (distance from the TBM to the surface).  

TBM Florence’s initial advance commenced last week. Tunnelling is being conducted in closed (slurry) mode and progress is slow and steady. In preparation for the restart of tunnelling at Tantangara, extensive geotechnical investigations were carried out on the headrace adit alignment, along with ground improvement works.  

Elsewhere on the project:  

• At Talbingo, the Snowy 2.0 project continues to make good progress with excavation of the tailrace tunnel. TBM Lady Eileen Hudson has excavated approximately 1,000 m since its relaunch in July.   

• Manufacturing of Snowy 2.0’s six pumped-hydro units that will generate up to 2,200 megawatts of power for Australia’s electricity grid is in full swing.   

• Five of the six 153 t, 13 m long, 7.5 m  and almost 3m high spiral cases have been manufactured, along with four draft tube liners and cones, three main inlet valves and other major power station components, including the first turbine runner. A headcover was transported the weekend of 18 November, with the first spiral case transported over the weekend of 1 December.The second of six spiral cases for the Snowy 2.0 power station was transported 442 km from Port Kembla to Lobs Hole in the Snowy Mountains, starting its journey late on December 8th night and arriving at its destination early on December 11 st morning.The remaining four cases will be transported in early 2024.  

Click here for a video,  here and au/38 for further information in the tunnelbuilder archive. Also visit https://www.nsw.gov.au/ and https://www.snowyhydro.com.au/.  50/23.