9 Comments

Great article! We also have different shapes of TBM these days like the "double O" and square designs!

https://en.wikipedia.org/wiki/Tunnelling_shield#/media/File:Shielded-machine.JPG

Expand full comment

I recently came across a very nice exploration of modern tunnel construction here: https://www.youtube.com/watch?v=6AV2NcyX7pk

Expand full comment

See also

https://petra.cc/

Petra has invented the first green trenchless multi-tool to bore through all geologies - including nightmare geologies like hard rock - at a variety of diameters, unlocking the ability to bore utility tunnels at scale.

Also

https://www.quaise.energy/

Expand full comment

An awesome article, thank you for all the time and effort you put into it! In Vancouver we currently have two tunnel-boring machines excavating twin subway tunnels (cut-and-cover was judged to be too disruptive), but I didn't know anything at all about the history of tunnel-boring machines. https://www.broadwaysubway.ca/construction/current-work/

Expand full comment

You'd need a lot of energy to heat the rock to melt it and to evaporate any water. You'd have to deal with various released volatiles and combustion side products. You'd need a tunneling machine that could work with molten rock. You'd have to pump out lava which means keeping it hot until can be dumped somewhere. You wouldn't want any humans near the cutting face. You'd have to come up with a shutdown procedure that doesn't leave the machine embedded in frozen rock.

Expand full comment

Great piece. Can you point me to the source for the 25% decompression deaths? Thanks!

Expand full comment

Typo -- subsistence should be subsidence.

Expand full comment

Why not melt the rock or soil?

Expand full comment