Components of the TBM – some weighing as much as 174t – were transported by special trailer to storage from where they will be eventually taken to the worksite. Built by CREG in China, the 11m-diameter TBM has been designed to excavate the 9% gradient, 2.6km main access tunnel to the power plant located 1km underground.
Excavation of the MAT is expected to start by the end of 2020. Once the TBM has completed its drive, it will start to bore the 5.8km-long tailrace tunnel. Exploratory construction work has been underway for more than 12 months with about 500 workers already busy on the project.
Webuild (formerly Salini Impregilo) is building the tunnels on behalf of Snowy Hydro as part of the Future Generation joint venture with US subsidiary Lane and local partner Clough.
Strategically located between Sydney and Melbourne, Snowy 2.0 will provide 2,000MW of energy generation. It will link two existing dams (Talbingo and Tantangara) through 27km of tunnels which include headrace, tailrace, pressure, penstock, draft tube, distributor, collector and access tunnels.
The turbines are reversible to allow water to be pumped back up to the top reservoir when surplus (cheap) energy is available – and be stored to generate energy on demand. As water is recycled between existing storages, it uses no additional water and gives water management flexibility, especially in times of drought.
