Concrete segment production completed for Snowy hydro dry access tunnels11 August 2022
Australia’s Snowy 2.0 precast factory has completed manufacture of all concrete segments for the hydro scheme’s 5.6km of dry access tunnels.
The factory at Polo Flat, Cooma, operated by the principal contractor Future Generation Joint Venture, has produced more than 25,000 of the seven-tonne segments that will line the main access tunnel and emergency, cable and ventilation tunnel at Lobs Hole.
In total, 36,000 or 27% of the 130,000-plus segments needed to line all of the Snowy 2.0 tunnels have now come off the Polo Flat production line, said Snowy Hydro managing director and CEO Paul Broad.
The factory supports the operation of the three TBMs, which are excavating 27km of tunnels from Tantangara Reservoir to Talbingo Reservoir for the Snowy 2.0 pumped-hydro expansion of the Snowy Scheme.
The Polo Flat facility includes a concrete batching plant and segment manufacturing from two automated carousels, producing up to 24 rings, each one made of nine segments, per day.
Many of the raw materials, such as aggregates and sand, are sourced from the local Schmidt Quarries at Mt Mary and Nimmitabel, which is reducing transport time and costs. Concrete is mixed within the batching plant, which is then transferred into the factory and poured into the moulds. Robotics are used to progress the moulds along the carousel as the segments cure and finish.
In March the third and final TBM was commissioned for Snowy 2.0, which is Australia’s largest renewable energy project.
Snowy 2.0 will significantly expand Australia’s pumped-hydro electricity generation and involves linking two existing dams, Tantangara and Talbingo, through 27km of tunnels. A new underground power station is also being built. When complete in 2026 Snowy 2.0 will deliver 2,000 megawatts of pumping and generating capacity and 175 hours of storage – enough to power 500,000 homes simultaneously – which will underpin thousands of megawatts of intermittent renewables.
In April 2019, the then Salini Impregilo (Webuild) won the AU$5.1bn (approx. US$3.59bn) contract as leader of the Future Generation JV which includes Webuild’s US subsidiary Lane, and Clough (Australia).
FAST FACTS – DRY TUNNEL SEGMENTS
- Number produced = 25,210
- Distance if all these segments were placed side-by-side = 86.3 kilometres
- Tonnes of concrete used = 151,260
- Equivalent rings (nine segments per ring) = 2,802
- These segments – designed to provide durability under extreme fire loads – have been laboratory tested for fire loads of 1,350 degrees Celsius for up to 120 minutes.
Snowy 2.0 project background: Snowy 2.0 is a nation-building project that will underpin thousands of megawatts of renewables and will continue to keep the lights on for generations to come.Snowy 2.0 will link two existing Snowy Scheme reservoirs, Tantangara and Talbingo, and its new power station with six pump-turbines will be located about 800m underground. Water in the top storage will be released for energy generation at times of peak demand and pumped back at times when there is excess renewable energy in the grid, so Snowy 2.0 is ready to meet demand when needed.