Article Image

IPFS News Link • Science, Medicine and Technology

Earthgrid aims to re-wire the USA using super-cheap tunnel tech

• New Atlas

Most tunnels dug today are made by massive, mechanical rotary boring machines, which scratch cutting wheels against rock and evacuate the debris behind them, lining the tunnel walls as they go. It's painstakingly slow, hugely expensive, and the cutting heads and drill bits often need changing or maintenance.

But there's another way to get through the toughest rock – as we outlined in our January article about Petra's thermal drilling robot. Blasting rock with high temperatures can fracture and vaporize the stone in a process called spallation, and blasting this damaged rock with high pressures causes it to flake, chip and blow away.

You can do this without touching the rock walls at all, so the equipment can do entire tunnels without stopping if necessary. It can run entirely on electrical power, opening up the possibility of entirely emissions-free drilling, and both Petra and Earthgrid claim it's much, much faster and cheaper than doing things mechanically – to the point where previously unfeasible projects can become economically viable.

The contactless cutting discs have plasma torches mounted in a Fibonacci spiral pattern, such that they cover the entire area of the hole when the discs are rotated