Going underground
Learn more about the reasons for tunnel boring and going underground as Dr. Kirsten and Manager Plant Engineer, Cameron head 366 metres underground to showcase Tumut 1 Power Station.
To get underground, there were many iterations of machinery. Currently, Snowy Hydro’s project Snowy 2.0 uses a few different Tunnel Boring Machines (TBMs).
It has been a long standing tradition, since the 1500s, for tunneling machines to be named after women. They also must be named before they are launched.
Key information
Learning area: STEM
Suitable for: year 5-8 classrooms
Topics: engineering, technology, physics
Duration: 30-45 minutes
Preparation: none
Materials: none
Resources
All teaching resources
This folder contains all teacher and student resources for this unit. By downloading this folder, you won’t need to download the individual files below.
Lesson guide
About our TBMs
Snowy 2.0’s newest Tunnel Boring Machine
This unit showcases our first three TBMs, but in late 2025, the fourth TBM on the Snowy 2.0 project has been named after a talented Tumut High School student who scooped top prize in an Indigenous art and storytelling competition.
Aspiring engineer Monica Brimmer, 15, wowed the judging panel with a stunning piece that reflected the spirit and purpose of Australia’s largest renewable energy project.
How TBM Monica is being transported
TBM Monica’s centre cutterhead piece was transported through Cooma en-route to the Marica worksite north of Kiandra.
What weighs more than 137 tonnes, is seven metres wide and is transported by 152 wheels?
An integral piece of Snowy 2.0’s new tunnel boring machine’s cutterhead!
At 73 metres long, the transfer was a sight to behold as it travelled up Sharp Street bound for the final leg of its journey on the Snowy Mountains Highway.
The cutterhead – which is the main excavation tool of a TBM – is too large to move in one piece and has been split into five. More than 140 big loads had been delivered to the Marica site from Port Kembla over the weeks preceding this big move.
More than 1500 people converged on Cooma on Sunday, October 12 to welcome the latest Snowy 2.0 big rig – one of the largest traffic loads ever transported in NSW.
The main drive of TBM Monica – an integral component of the project’s fourth mega borer – drew an excited crowd of onlookers to Cooma town centre.
Spectators also flanked driveways and homes between Bredbo and Adaminaby to catch a glimpse of the big rig.
The convoy tipped the scales at a mammoth weight of more than 450 tonnes – across five trucks and a trailer, driven by 210 wheels across 35 separate axles. Snowy Hydro Head of Social Impact and Community Sarah Norris described the transfer as a major milestone for both the project and the community.
“We were blown away by the attendance – it was a truly special evening, with an incredible atmosphere, as people lined the footpaths for the best vantage point to watch,” she said.
“It almost felt like a festival was taking place – we had free hot choccies and coffees and talented musician Leon Fallon on-hand to keep the crowd entertained
“Thanks to everyone who attended, we appreciate there were quite a few little people that stayed up past their bedtimes to witness a little piece of Snowy history.”
The mega transfer evoked memories for some community members of the mighty Thornycroft Antars hauling machinery and construction equipment through Cooma as part of the original Snowy Scheme decades ago.
There are 23 oversize loads being carefully planned and transported to Snowy 2.0 sites over the coming weeks associated with the assembly of TBM Monica.