Work progresses at Snowy 2.0

The main access tunnel portal has been finished at Lobs Hole, ready for drilling to begin in the coming months.

Construction continues at Lobs Hole and Polo Flat on Snowy 2.0, with work underway to prepare a cradle for the Tunnel Boring Machine (TBM), a communications fibre optic cable being laid through Talbingo Reservoir and a portal prepared to start excavation for the main access tunnel.

Talbingo residents may have seen the barge being used to lay the communications cable, which will provide communications from the Tumut 3 Power Station to the main access tunnel (MAT) at Lobs Hole.

Snowy Hydro said the MAT portal has been finished and within the coming months, the first of three TBMs will begin drilling the 2.7 kilometre tunnel down to the power station cavern, which lies “hundreds of kilometres” underground.

The cradle for the TBM is being prepared at the port site, while a water treatment plant is being constructed to treat and recycle the water which will be used by the TBM.  

In order to assemble the TBM’s “massive” 11m-diameter cutterhead, main drive and front shield, a 750-tonne crawler crane is being built onsite. The feat in itself requires a 300-tonne crane to build the crawler crane. The 300-tonne crane is also being used to install the TBM tailskin. 

“To deliver power to the TBMs, worker accommodation camps and other construction activities at Lobs Hole and Tantangara, an onsite electricity substation is being built,” said Snowy Hydro representatives.

A barge installs a communications fibre optic cable at Talbingo Reservoir.

Two large, green transformers have also been delivered to the site, to convert electricity to a lower voltage. The transformers weigh approximately 85 tonnes each and were transported through the mountains on trailers with prime movers at each end.  

At Polo Flat in Cooma, the concrete segment factory is under construction, with Snowy Hydro projecting it will start operations by the end of the year and manufacture about 130,500 concrete segments to line Snowy 2.0 waterway and access tunnels.