The Marica shaft, as part of Snowy Hydro 2.0, is continuing to progress with it currently being over 80m deep.
The surge shaft has two key purposes for the operation of a hydro power station: as a water storage and vacuum relief when the power station starts up, and to absorb the momentum of water movement within the headrace when the power station is shut down.
Snowy Hydro is excavating the shaft with a number of excavation methods, including using 36-tonne excavators that place loads of material into kibbles.
Currently, an integrated work platform and personnel hoist is in the final stages of commissioning to provide worker access.
According to the latest project update, building in steep terrain was challenging and required specialised rope access workers to install ground support for safety and stability.
Over at Tantangara, drill and blast excavation to join the intake and gate shaft is underway from both structures. The transition from the intake changes shape as it is excavated to become the connection tunnel to the gate shaft.
At the same time, Snowy Hydro has started drilling and blasting from the gate shaft to merge into the headrace tunnel alignment excavated by TBM Florence.
When completed, water will enter the headrace tunnel from the intake, on its way to the power station.
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