Earthgrid Aims To Rewire the USA Using Super-Cheap Tunnel Tech - Slashdot

2022-07-22 17:37:34 By : Mr. Michael Hu

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That's a lot of energy concentrated into a small area. Presumably the rocks are going to get rather hot. How does that energy consumption compare to more traditional methods?

All that power in one spot - why doesn't it melt the plasma machine, and the support stuff behind it?

Don't worry, they will use AI to solve that problem.

Naw, I'd bet on Data Science!

Maybe I'd hedge and allow they might fix it with cryptocurrency.

I think you're on to something! They could take the energy they're burning to mine cryptocurrency and use THAT to melt the rocks.

This is basically super plasma cutters - also known as magic fire - which uses compressed air that has been ionized to transfer the energy to the object to melt. The air passing by pulls residual heat from the nozzle that it absorbs from the plasma radiant heat. As long as you have proper air flow for the for the amount of power you are dumping in the nozzles last just fine...

They likely will also have a heat sink/water cooling - but the big challenge will be ensuring the vaporized rock makes it to the outer wall to form a glass casing..

From a technical challenge aspect is how they are going to feed this think power - that amount of power sustained for any real amount of time will be a big challenge to deliver logistically..

That is for boring a 10-meter (33-feet) diameter tunnel.

This technology would make way more sense for really small bores, like boring a one-inch conduit between my house and the cable access point.

A fast and cheap boring machine would be way easier than trenching.

An impact mole or an horizontal drill/auger already goes through soil fast with minimum wear.

Soil isn't the problem, rocks are. If you have only soil to deal with you can hydrodrill your way under a road with nothing but a piece of PVC pipe fitted up to a water supply at around 80 psi or so. But it doesn't cut through rocks, even if you do it with a pressure washer (at over 1000 psi) so there remains an unsolved problem there. A 1" plasma tunneler could actually be massively useful. I imagine it would take a lot of jobs to pay for it, though. It makes more sense to start with wherever the peak cost

How to deal with the massive heat would seem to be a bigger issue than they are making it.

That is probably why this is in the funding stage. Lots of ideas that seem good at first glance on paper but have significant simple overwhelming defects get to the funding stage, and dumb investors give them money. Usually the designers either don't think the idea through, or they think that technology will be able to magically solve the basic massive issue with the idea. Something for the designer to work on and

It's obviously made from Unobtainium. /TheCore

But where is that much electric power coming from? What kind of extension cord can carry that wattage?

The highest voltage power line ever constructed was just 1,150 kV [wikipedia.org]. At that voltage, 1.38 gigawatts would be 1200 amperes. That would be three parallel 600 to 750 KCMil copper wires, each of which is, as the name implies 0.6 to 0.75 inches across.

The bigger problem is that the dielectric breakdown voltage of air is about 1 megavolt per meter. So without insulation, you'll need significantly more than one meter of air between that wire and anything that qualifies as a ground. And of course, with insulati

They would likely use multiple cables. For reference, the 350kW EV chargers that are widespread in Europe carry 500A on a water cooled cable that can be handled easily and safely by an untrained person.

The reason they are only 350kW is the battery voltage, which is nominally 800V but goes up to 960V when fully charged.

They would likely use multiple cables. For reference, the 350kW EV chargers that are widespread in Europe carry 500A on a water cooled cable that can be handled easily and safely by an untrained person. The reason they are only 350kW is the battery voltage, which is nominally 800V but goes up to 960V when fully charged.

They would likely use multiple cables. For reference, the 350kW EV chargers that are widespread in Europe carry 500A on a water cooled cable that can be handled easily and safely by an untrained person.

The reason they are only 350kW is the battery voltage, which is nominally 800V but goes up to 960V when fully charged.

I searched for a cable for a single plasma cutter, it looked about 3/4" thick. So for the 72 cutter model maybe the cable total diameter will be about 3 feet thick

That's WAY too thick a cable.

72x the current = 72x the cross sectional area = sqrt(72)x the diameter = 6.4 inches thick.

That's WAY too thick a cable. 72x the current = 72x the cross sectional area = sqrt(72)x the diameter = 6.4 inches thick.

That's WAY too thick a cable.

72x the current = 72x the cross sectional area = sqrt(72)x the diameter = 6.4 inches thick.

Because you are looking at low voltage cables.

"So how do you plan on keeping the voltage from overcoming the insulation and jumping to Earth"

You isolate the supply from the earth so its floating, Simple. You then have to worry about the insulation between the two (or more likely three) conductors. But you didn't ask that question.

The Soviets had a similar system for boring train tunnels through mountains. They would melt and glassify the rock and smoosh it into a tunnel with expanding mechanical arns/forms and then pair that rig with a standard track-laying train car so they could slowly but surely melt and lay track iteratively. The idea was to go fast by eliminating tailings and fumes - one of the cars on the construction train was a fission reactor.

It was sidelined when they ran out of money for new infrastructure (late 70's).

For that kind of power requirement I would guess they use either high voltage AC or DC, which keeps the cable down to a manageable size.

Any idea what voltage the thermal lance was powered by?

As far as cables moving (presumably due to their magnetic interaction - a conducting loop will try to push itself into a circle) - the force moving them is proportional only to the current. Deliver 1000x the power using the same current and 1000x the voltage, and the you could use the exact same cable, which would experience the exact same heating and magnetic forces. Only question is if the insulation could still prevent current flow at those voltages

I misread the name of the company as Earthgrind, not Earthgrid. Earthgrind is a better name, anyway!

> But it also hopes to put enough interlinking customer projects in place to create a subterranean network spanning the entire contiguous USA

Rat and cockroach super network, just what we need.

Come on, stop worrying about all those details, and get with the program!

You need to support the roof in unstable formations, seal against water leaks

You need to support the roof in unstable formations, seal against water leaks

The plasma torches are burning away at 27000 degrees. There is a good chance this means that the surrounding rock will become hot enough to become slightly molten. A similar drilling project [slashdot.org] stated that this effectively creates a solid pipe of rock and seals the tunnel while it's burning away rock. They may add an extra layer of material for safety but it won't need to be anything of great significance.

Quite possibly. At least these guys seem to have some novel technology, unlike the Boring Company that just dug completely normal tunnels and then put in a single lane road with all the associated bottlenecks.

What's happening, is some shyster came up with a cool-sounding idea that he hopes will deprive some rich idiots of their money, with big promises and charisma.

This would be ideal for both lunar and martian drilling.

This would be ideal for both lunar and martian drilling.

Runs on electricity. We don't have an extension cord that long.

The biggest challenge is not the cutting through the material; it's making sure the tunnel doesn't collapse. There are even multiple *types* of tunnel boring machines to deal with various ground compositions.

Assuming this machine actually works as advertised, all it will take is one pocket of sandy or loose material, or groundwater, and it's fucking done. =Smidge=

The biggest challenge is not the cutting through the material; it's making sure the tunnel doesn't collapse. There are even multiple *types* of tunnel boring machines to deal with various ground compositions. Assuming this machine actually works as advertised, all it will take is one pocket of sandy or loose material, or groundwater, and it's fucking done.

The biggest challenge is not the cutting through the material; it's making sure the tunnel doesn't collapse. There are even multiple *types* of tunnel boring machines to deal with various ground compositions.

Assuming this machine actually works as advertised, all it will take is one pocket of sandy or loose material, or groundwater, and it's fucking done.

Actually, I suspect it would work fine for sandy or loose material as long as you get it hot enough. Sand would turn into a layer of glass, and other loose material would turn into a layer of igneous rock.

Groundwater, however, would vaporize into steam, with quite possibly explosive results. I wouldn't want to be anywhere near it if that happened.

At that temperature, I suspect steam will dissociate into its components ie. H2 and O2. Yikes. I hope there won't be an open flame anywhere near. Now wait a minute...

Supersonic, superheated rock drill have been around awhile. The rocket drill [wikipedia.org], burning chemical fuel was invented in the 1940s, and plasma jet drills [wikipedia.org] at least on a demonstration basis have been around for a few decades as well. I remember Union Carbide using some kind of incandescent jet drill on taconite formations in the 1960s. I don't know why the technologies have not seen more adoption before now.

Probably because the huge amount of heat generated is a big problem for humans trying to dig a tunnel. If you have a robot that can survive in that environment it becomes practical.

And if your tunnel is through sandy soils below the water table, what then (other than a steam explosion, of course)?

Y'all also realize that tbms do more than drill, right? They line the tunnel walls with concrete, for one thing. This thing uses up a good sized power plant's output (a nuclear reactor outputs about 400MW) for a bore of questionable smoothness (pop! pop! crackle! crackle!) that's too small to get any workers in to install liners or utilities.

Fifty bucks says this thing exists in PowerPoint land only, with maybe a few kW laboratory experiment as a proof of concept. Possibly made out of a cots cutting torch.

Y'all also realize that tbms do more than drill, right?

Y'all also realize that tbms do more than drill, right?

Y'all do realize that not all tech has to work perfectly everywhere to be worth using, right?

This technology seems like it would be fairly worthless for anything other than digging a tunnel through solid rock. That's pretty cool, though, since that's not easy now.

Binary thinking is both your friend and your enemy.

It is your enemy when you only recognize "perfection" and "uselessness." There are degrees of applicability.

It is your friend when you recognize that if you have a gizmo whose physics-based limits confine it to solving a very small fraction of your problem, one that you can solve already, then your gizmo is not a game-changer and is probably not worth using.

First, this is not "100x faster" at all. Horizontal boring techniques for cables and pipes already do 100m per day and more. So this is, at best, 10x faster. Second, established horizontal boring techniques cost down to $30 per meter, depending on circumstances. So this is about 10x as expensive. It has the advantage that it can drill up to 1m in diameter (well, it "potentially" can), while traditional horizontal boring techniques only go up 60cm diameter, at least the ones I actually found on offer.

Now I just looked at very few websites to get this info, it may well be possible the supposed advantages over traditional, established, known and reliable techniques is even lower and may well be non-existent.

All in all, some people with a big mouth that like to lie by misdirection and a product that is flashy but probably has only very limited applicability.

They said "up to" so there's no lies. They're 100x faster than a guy with a shovel who takes a long lunch break, and 100x cheaper than the most overpriced project anywhere ever.

It is called "lie by misdirection". It is a favorite of scammers (and marketeers) because you cannot usually be sued for it.

Wonder why the Fibonacci spiral placement of the torches on the cutting head? Must be something like it concentrates the heat at the center and then helps flow the molten rock out to the edges for forming the tunnel walls, and the outer part of the arm will only pass by the walls once per rotation so as to give them time to cool(harden). Anyone an engineer that groks this stuff?

Even if it's only feasible for small bores, it would be great for putting power lines underground.

I live in a 30-year-old development where the power lines are underground. In the ... 26 years I've been here, we have rarely lost power for more than a minute. The DC area storms last week knocked nearby neighborhoods off for hours to days - the lights blinked here once or twice.

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