- The Snowy Delivery team has completed 570,000 cubic metres of excavation of the Talbingo intake. The intake is where water will exit and enter the tailrace tunnel, connecting the lower Talbingo reservoir to the underground power station
- Excavation of the Marica surge shaft has reached 95 metres. Mechanical excavation including rock breakers and excavators continues, with drill and blast methods also being used. Once complete, the 28 metre-wide and 250 metre-deep surge shaft will be used for water storage and pressure relief when the power station starts up, and to absorb the momentum. The Marica surge shaft will be one of the largest shafts of its type in the world
- Excavation of the gate shaft at Tantangara is complete, with drill and blast work to excavate the transition tunnels linking it and the intake well advanced. The gate shaft is used to stop and start the flow of water into the headrace tunnel and power station for maintenance purposes or in the case of an emergency
Tunnel Boring Machines (TBMs)
Florence
Florence is the TBM excavating the 16 kilometre headrace tunnel, which will connect the underground power station to the upper Tantangara reservoir
Following a seven-week operation to use ultra high pressure water jetting to remove very hard rock preventing the TBM from progressing, TBM Florence restarted excavation on Thursday 11 July
The Snowy delivery team expects highly variable ground conditions to continue ahead of TBM Florence, which will mean progress will continue to vary, particularly as the TBM navigates the curve leading to the main tunnel alignment
Lady Eileen Hudson
TBM Lady Eileen Hudson, which has completed the 2.8 kilometre main access tunnel to the power station, is now excavating the 6 kilometre tailrace tunnel, which will connect the underground power station to the lower Talbingo reservoir
The machine is progressing well and is approximately 3.0 kilometres into the tailrace tunnel
A conveyor belt extension and service modifications have recently been carried out so excavations to join the tailrace tunnel with the Talbingo intake excavation can commence
Kirsten
Kirsten is the TBM excavating the 1.6km Inclined Pressure Shaft (IPS – connecting the underground power station to the headrace tunnel that leads to the upper Tantangara reservoir), having already completed the 2.9km emergency, cable and ventilation tunnel
TBM Kirsten has installed 14 trial tunnel lining rings in the IPS using locally manufactured concrete segments specifically designed for the high water pressures that will be experienced in the IPS
Tunnelling of the IPS will be a pioneering engineering challenge, with the shaft’s incline reaching a steep 47 percent