The Snowy 2.0 project continues to make significant strides with its Tunnel Boring Machines (TBMs) advancing the construction of critical infrastructure. Here is the latest update on the progress of TBMs Florence, Lady Eileen Hudson, and Kirsten. 

TBM Florence 

Florence, the TBM excavating the 16-kilometre headrace tunnel, has resumed operations following a seven-week hiatus. The TBM had encountered very hard and abrasive rock, necessitating the use of ultra-high-pressure water jetting to remove a section of it. Excavation resumed on Thursday, July 11. 

The Snowy delivery team anticipates Florence will continue to encounter highly variable ground conditions, which may impact progress, especially as the TBM navigates the curve leading to the main tunnel alignment. 

TBM Lady Eileen Hudson 

TBM Lady Eileen Hudson, which successfully completed the 2.8-kilometre main access tunnel to the power station, is now focused on excavating the 6-kilometre tailrace tunnel. This tunnel will connect the underground power station to the lower Talbingo reservoir. Currently, Lady Eileen Hudson has progressed approximately 3.0 kilometres into the tailrace tunnel. 

Recent modifications, including a conveyor belt extension and service updates, have been completed to facilitate the connection of the tailrace tunnel with the Talbingo intake excavation. 

TBM Kirsten 

Kirsten is tasked with excavating the 1.6-kilometre Inclined Pressure Shaft (IPS), which will link the underground power station to the headrace tunnel leading to the upper Tantangara reservoir. Kirsten has previously completed the 2.9-kilometre emergency, cable, and ventilation tunnel. 

To date, Kirsten has successfully installed 14 trial tunnel lining rings in the IPS using locally manufactured concrete segments. These segments are specially designed to withstand the high water pressures anticipated in the IPS. Tunnelling the IPS presents a pioneering engineering challenge due to the shaft’s steep 47 per cent incline.