By Lynda Myer
In order to housing power, water and fiber optic cable for communications across three of the Snowy 2.0 sites, boreholes are being drilled for the pipes using HDD drilling method at Lobs Hole on Australia’s Snowy 2.0 pumped hydro project.
The intended boreholes with 2.2km-long have been extended from Lobs Hole to Marica and are initially 300mm in diameter having an elevation difference of 650m.
From top and bottom, two drilling operations are under way and are due to join up to create a continuous borehole before being enlarged to 660mm in diameter.
According to Snowy 2.0 Lobs Hole construction manager Will Binsted: “The drilling required a high level of skill to maintain directional control while operating a drill string up to 1.8km long. Snowy 2.0 has contracted HDD company Michels for the project.”
The advantages of these boreholes are eliminating the require to construction of almost 5km of roads and digging up to 60m cuts in the steep terrain, helping minimize environmental impacts.
Additionally, for taking services beneath the Snowy Mountains Highway and waterways across the plateau through to the Tantangara worksite, HDD techniques will be used.
Considering that the current location of the 28m-diameter headrace surge shaft at Marica is one-fifth of the way to its final depth of 263m and drill and blast activities have commenced, two 25-tonne capacity hoisting buckets, or kibbles, are being used to load excavated rock.
The shaft now is placed at over than 50m deep, so an integrated work platform and personnel hoist is being installed to provide worker access, whereas ventilation ducts have also been installed.
Following that the tunneling process of the tailrace adit has been completed at Talbingo, currently TBM Lady Eileen Hudson is excavating the tailrace tunnel alignment and heading towards the power station complex, which is an indication of the start of the first power waterway on the Snowy 2.0 project.
“Excavation is ahead of schedule, with more than 26m recently excavated in a single day. The tailrace tunnel is 6km in length, with TBM excavation continuing through to mid-2025,” said Binsted.
Providing deep storage central to Australia’s renewable transition, Snowy 2.0 is the largest renewable energy project under construction in Australia and once completed, it is slated to deliver 2,200MW of dispatchable generation. The scheduled date for commercial operation of all units is December 2028, with first power expected in the second half of 2027.
