Snowy 2.0 sets new tunnel boring machine to work, completes 46 underground concrete pours

Snowy 2.0 has set to work a fourth tunnel boring machine, a $75 million piece of drilling equipment purpose built to complete excavation of the huge pumped hydro project’s “geologically challenging” 17 kilometre headrace tunnel.

The new machine made its ceremonial first rotation on Sunday, marking what Snowy Hydro and its federal government owners will be hoping is the beginning of a new run of productivity for the controversial project in the New South Wales Snowy Mountains.

In October, yet another major blowout in the costs for Snowy 2.0 was flagged by company executives, raising fresh questions over whether the already long-delayed project can meet its amended completion date of December 2028.

Snowy 2.0 was originally unveiled by the Turnbull Coalition government in 2017 with what was an absurdly low cost prediction of $2 billion.

After several cost blowouts, a reset in 2023 – after the departure of former CEO Paul Broad – put the costs at $12 billion. But energy experts have said repeatedly that the total bill will exceed $20 billion.

One of the biggest reasons for cost blowouts and project delays has been the staggeringly slow progress of the project’s tunnel boring machines (TBMs), and in particular TBM Florence, which has been confounded by a range of unforeseen challenges, ranging from rock too hard to penetrate to land too soft to drill.

Snowy Hydro hopes the new TBM, named Monica in honour Tumut High School student Monica Brimmer – the winner of a First Nations art and storytelling competition – will be better equipped for the job, with its purpose-built 12-metre cutterhead.

Snowy Hydro says TBM Monica will begin tunnelling in earnest in the coming weeks, launching from the project’s Marica worksite, just outside Kiandra – a former NSW gold mining town – to make its way through the geologically challenging Long Plain Fault Zone of the headrace tunnel.

The company also claims that significant progress is being made elsewhere in the project, including at the Lobs Hole worksite, where the focus is shifting from tunnelling and excavation to preparing the fitout of an underground power plant “the size of Sydney Opera House.”

“To prepare for this, 46 permanent concrete pours have already been completed,” Snowy Hydro says.

“More than 733,000m3 of underground excavation – equivalent to 293 Olympic-sized swimming pools of material – has taken place in the huge subterranean caverns that were created using drill-and-blast techniques, some of which were pioneered on the original Snowy Scheme.

“More than 5,200 workers are delivering Snowy 2.0 across four major project workfronts and in excess of $300 million has been invested in the local economy.”

All up, the company says the project is now more than 70 per cent complete and Snowy Hydro chief Dennis Barnes recently insisted the project remains on track to be delivered by the December 2029 deadline.

On costs, however, Barnes has said it could take nine months for independent experts to complete and verify a reassessment.

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