The Snowy 2.0 project has achieved two important milestones this month with Factory Acceptance Testing (FAT) for TBM 4 as well as 25 new Auxiliary Transformers for pumping operations.

TBM 4

The fourth Tunnel Boring Machine (TBM 4) required to tunnel through a challenging geological fault zone has got the green light after passing the factory acceptance testing.

The TBM was assembled for extensive testing of its critical functions to verify the machine meets all technical and operational specifications before it is delivered to site.

The cutterhead, drive motors, thrust cylinders and other critical machine functions required to advance and operate the machine were all tested in the factory and demonstrated at a special ceremony to mark the completion of the FAT.

Snowy Hydro’s 2.0 Project Director Dave Evans and FGJV Project Director Fabrizio Lazzarin attended the ceremony in China, along with Senior Underground Engineer Vikum Chathuranga and Senior Tunnel Engineer Nick Chapman.

TBM 4 has been specially designed to meet the unique geological and environmental challenges. It is a multi-mode TBM capable of operating in EPB and slurry mode through variable ground conditions, including the Long Plain Fault Zone, along the headrace tunnel alignment. It requires robust mechanical systems capable of handling hard rock conditions, fractured rock conditions, high water pressures, and remote operations. It has a 12m diameter cutterhead and the TBM integrates advanced slurry treatment and grouting systems to ensure continuous excavation and environmental compliance.

Now the FAT testing has been completed, TBM 4 will be disassembled and transported to Marica, where it will be assembled and ready to start excavating later this year.

Auxiliary transformers

Newly manufactured Auxiliary Transformers recently passed the Factory Acceptance Testing (FAT) in China.

The 25 new transformers have been custom made for each specific area where they will be located – in the hydraulic structures of the intakes at Tantangara and Talbingo, GIS, MAT and in the Transformer Hall of the powerhouse complex at Lobs Hole.

Each auxiliary transformer will play a crucial role in providing power for the pumped hydro operations. The transformers adjust the voltage of the electricity generated by the turbines in the Machine Hall so it may travel through the transmission lines of the electrical grid.

The transformers can generate up to 20,000 KVA which is significantly higher than generation from the auxiliary transformers of the existing Snowy Scheme.

The auxiliary transformers have been engineered to use no oil during operation that will reduce the risk of fire and oil spill. They feature special alarms and protection systems installed for efficient operations and maintenance.

All components of each transformer were successfully tested in the factory to ensure the transformers' safety features and performance capabilities comply with the specification

and Australian standards.

Green light for Factory Acceptance Tests