Once too soft, now too hard: Snowy 2.0 tunnelling machine Florence comes to a stop again

The problem-plagued and controversial Snowy 2.0 pumped hydro project has hit yet another snag, with its tunnel boring machine Florence halted once again, this time because it has become wedged in hard rock.

The federal government owned Snowy Hydro – already facing massive delays and huge over-runs on costs for the project – announced this week that TBM Florence had halted operations a week ago, on Thursday, May 16.

It said TBM Florence had already slowed due to “very hard and abrasive rock” a day earlier, before “the project ceased excavation … on Thursday 16 May due to rock pinching on the machine’s shield.”

The TBM had been making slow progress in recent weeks as it cut through the hard rock at its Tantangara site, one of several drilling locations in Kosciuszko National Park.

According to ABC News, the problem arose because “Florence was mistakenly turned too sharply from a straight line into a curve, causing part of the cutting head to become wedged. Further boring compounded the problem, with the machine making only incremental movements since.”

Snowy Hydro said it had “sought immediate advice from a specialist contractor with experience at other Australian projects with the same TBM situation” and subsequently began using high pressure water jets in an effort to remove the rock “impinging on TBM Florence’s shield.”

The company says it is unsure when excavation will recommence saying only that it “will be determined on the successful removal of the rock.” It says it will provide an update next week.

The Snowy 2.0 project has blown out from an original cost estimate of around $2 billion to $12 billion – not including the cost of transmission to properly connect to the grid – and delays which have pushed the project completion out to the end of the decade.

Florence is supposed to be excavating some 16 kms of the headache tunnel but not even completed a single kilometre and has been slowed to a snail’s pace – even after finally restarting after getting bogged for months in soft soil.

ABC News suggested the situation is much more serious than has been publicly acknowledged by Snowy Hydro and could take weeks or even months before normal drilling resumes.

One source told ABC News that they had “wedged the thing in good and proper,” with another commenting somewhat more succinctly, “It’s f****d.”