The Snowy 2.0 pumped-hydro megaproject has marked a significant milestone, with one of three TBMs, Lady Eileen Hudson, now two-thirds of the way through its second tunnel excavation.

The TBM is approximately 4 km into the 6 km tailrace tunnel, which will link the lower Talbingo Reservoir with the massive 20-storey underground power station. TBM Lady Eileen Hudson previously completed a 2.85 km main access tunnel, which is now being used by construction teams to reach the underground power station site.

 Drill and blast works are also advancing at the Talbingo water intake, creating a new 700-m tunnel between the intake structure and the tailrace tunnel. The Talbingo intake is located in very steep terrain and following excavation of 570,000 cubic metres of material over two years, the rock face is now 110 m high.

 Snowy 2.0 will have a generating capacity of 2,200 megawatts and an unmatched 160-hour storage capability, meaning it will be able to power around 3 million homes for a week. Overall the Snowy 2.0 project is around 60 percent complete and it's on track to be delivered within the $12 billion budget and be complete by the end of 2028.

Across the project, more progress is being made:

• In the underground power station complex, the caverns are more than 27% excavated.
• At Marica, the 28-m wide surge shaft is excavated to 123 m, or half of its final depth. The shaft will provide water storage when the power station starts up and pressure relief in the headrace tunnel when it shuts down.
• TBM Florence is progressing well, excavating the 17-km long ‘headrace’ tunnel that will link the upper Tantangara water reservoir to the underground power station, with more than 1,600 m excavated. TBM Kirsten is performing to plan and is now excavating the 1.6-km, very steep tunnel that will link the headrace tunnel to the underground power station. Ground conditions ahead of all TBMs are expected to be inconsistent and the performance of the machines will vary as a result.
• The NSW Department of Planning, Infrastructure and Housing is currently assessing the planning modification to enable a fourth project TBM, which is required to tunnel through a challenging geological fault zone.

Click here for a video,  here and au/38 for further information in the tunnelbuilder archive. Visit https://www.snowyhydro.com.au/.  45/24.