New technology claimed to increase TBM boring speeds

27 April 2021


New geothermal energy technology to be tested by three companies who intend to drill the deepest borehole in Europe could also be used to speed-up the tunnelling process.

The new process comprises a pulse plasma drilling bit which does not require rotation and is claimed to disintegrate any material without direct contact. As it can be used both vertically and horizontally, it could also be applied to tunnelling. This is the attraction for Finnish company Finest Bay Area Development (FEBAY) which is leading the project to build the world’s longest underwater rail tunnel of 103km between Helsinki and the Estonian capital Tallin.

The three companies – Slovakia-based GA Drilling, FEBAY, and Finnish-owned development company Callio – have agreed to test and develop the ‘Plasmabit’ geothermal solution at the Pyhäsalmi mine in northern Finland. At over 1,400m deep, it is the deepest base-metals mine in Europe and has more than 100km of tunnels.

In drilling the deepest geothermal bore in Europe, the three aim to show how the Plasmabit solution developed by GA Drilling may allow carbon-free geothermal energy to become a ‘ubiquitous and affordable’ primary energy source.

According to a recent joint statement from the three companies, Plasmabit opens up the possibility of ultra-deep drilling, creating geothermal wells quickly and cost effectively up to 10km deep, generating not just heat but also electricity.

Plans are also in place to test the plasma drilling technology for use on TBMs boring through the tough bedrock of the Finnish mine. Like Elon Musk’s claims previously, these latest statements suggest that TBM boring speeds could be increased by up to ten times.

FEBAY co-founder Peter Vesterbacka said: “This is the kind of innovation that we have been talking about in connection with the [Helsinki-Tallin] tunnel project. Fantastic European tech and business coming together to change the world for [the] better on an innovation platform.”