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National Boards => General Highway Talk => Topic started by: kernals12 on January 02, 2021, 09:07:34 AM

Title: Tunneling with Heat
Post by: kernals12 on January 02, 2021, 09:07:34 AM
Digging a tunnel is a long, arduous, and costly process, whether it be done by men with steam shovels or by gigantic tunnel boring machines. But what if you could just melt or vaporize the rock?

https://youtu.be/TwA7c_rNbJE?t=135
Perhaps the most famous talk about this comes from Disney's Magic Highways from 1958 (go to 2:15)


(https://i.imgur.com/MhurSUc.jpg)
But in the early 70s, the people at Los Alamos decided to try making this dream into a reality with what they called a nuclear subterrene (https://www.osti.gov/servlets/purl/4687637). It worked by having a nuclear reactor circulate extremely hot liquid to the face of the borer which would cause the rock in front of it to melt. There were many advantages to this (https://www.nytimes.com/1971/12/25/archives/thermal-boring-device-melts-away-granite.html): it could dig much faster, the resulting tunnel would have smooth glassy walls that wouldn't need concrete lining, the subterrene didn't have the tendency to turn downward that conventional drills did, and the subterrene could be shaped in any arbitrary way; triangular, square, or hexagon, as it didn't need to be round.

I can't find much information on the exact fate of this project, but I assume it was doomed by the same problems as nuclear power in general: cost.

(https://i.imgur.com/ccMdgaM.jpg)
MIT Professor Paul Woskov holding a sample of rock with a hole made by his gyrotron.

But now interest in non-mechanical methods of making tunnels seems to be returning. A group of scientists at MIT are working on ways to use millimeter waves (https://spectrum.ieee.org/energy/renewables/altarock-energy-melts-rock-with-millimeter-waves-for-geothermal-wells) to break up rock. Their main ambition is for geothermal wells, but certainly that would work for any type of tunnel, including highway tunnels. And with extremely low cost solar power on the horizon, the problem that such a device would require a lot of energy could be rendered moot.

Title: Re: Tunneling with Heat
Post by: Road Hog on January 02, 2021, 08:47:31 PM
Anything with "nuclear" in its title these days is DOA out of hand.
Title: Re: Tunneling with Heat
Post by: kernals12 on January 02, 2021, 08:50:42 PM
Quote from: Road Hog on January 02, 2021, 08:47:31 PM
Anything with "nuclear" in its title these days is DOA out of hand.

Because it's way too expensive.
Title: Re: Tunneling with Heat
Post by: Roadgeek Adam on January 02, 2021, 09:10:09 PM
Too bad there's this thing called human lives who would be at risk for nuclear blasting.

Chernobyl and Fukushima wants a word with you.
Title: Re: Tunneling with Heat
Post by: Duke87 on January 02, 2021, 09:11:57 PM
Quote from: kernals12 on January 02, 2021, 08:50:42 PM
Quote from: Road Hog on January 02, 2021, 08:47:31 PM
Anything with "nuclear" in its title these days is DOA out of hand.

Because it's way too expensive.

Y'know, there's this other (https://en.wikipedia.org/wiki/Three_Mile_Island_accident) teensy little (https://en.wikipedia.org/wiki/Chernobyl_disaster) thing about (https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disaster) anything involving nuclear fission that tends to get in the way of it being implemented, regardless of cost.
Title: Re: Tunneling with Heat
Post by: cl94 on January 02, 2021, 09:13:51 PM
There's a reason this hasn't been talked about since the 1970s. Look up Project Plowshare.
Title: Re: Tunneling with Heat
Post by: kernals12 on January 02, 2021, 09:14:50 PM
Quote from: cl94 on January 02, 2021, 09:13:51 PM
There's a reason this hasn't been talked about since the 1970s. Look up Project Plowshare.

It's being talked about now as I explained in the OP.
Title: Re: Tunneling with Heat
Post by: vdeane on January 02, 2021, 10:00:42 PM
This sounds like The Core!
https://www.youtube.com/watch?v=ZkynnGqL7QM
Title: Re: Tunneling with Heat
Post by: Max Rockatansky on January 02, 2021, 11:57:03 PM
Disney visions of the urban future and nuclear anything should never mix.