Tunnel Boring Machines / Technology

Although very sketchy info is on the net regarding these nuclear powered machines. Was wondering if any one on here can shed more light on this technology, which is supposedly only with the us and probably Russian military.

a reply to: Nochzwei

There is actually quite a bit of info if you just Google it.
The tech is pretty fascinating to research.

originally posted by: nugget1
a reply to: Nochzwei

There is actually quite a bit of info if you just Google it.
The tech is pretty fascinating to research.

Ive seen but no schematics of any sort and what keeps the nuclear reactor cool

They're nuclear powered? My girlfriend's dad is an engineer who has helped design tunnel boring machines but I've never heard of them being nuclear powered. Maybe I'll ask him a few questions about it.

There are many reports of mysterious humming sounds that seem to be emanating from the ground. Underground tunneling seems like a plausible explanation.
en.wikipedia.org...

Last i read. Up on that was like 8or 10 years ago. Seem like they use the stuff they bore through melt it and create nice solid glass / melted rock walls at the back as they go forward. Will we ever realy know the truth.

originally posted by: Aldakoopa
They're nuclear powered? My girlfriend's dad is an engineer who has helped design tunnel boring machines but I've never heard of them being nuclear powered. Maybe I'll ask him a few questions about it.

I think you misunderstood, regular TBM:s is not nuclear powered, regular TBM:s just bore its way into the bedrock or whatever medium it is drilling into, the nuclear powered on the other hand is rumored to melt rock instead of drilling it.

originally posted by: neversaynever
Last i read. Up on that was like 8or 10 years ago. Seem like they use the stuff they bore through melt it and create nice solid glass / melted rock walls at the back as they go forward. Will we ever realy know the truth.

These tunnel boring machines had a nuclear reactor on board. The cooling system for the reactor used liquid sodium to transport the heat to the cutting end, but the other advantage of using sodium was that it would be hot enough for rock to melt as well. So the machine could melt rock where it would resolidify into glassy pebbles or slabs and they could be transported back out. All fissures and cracks in the rock are sealed, leaving a perfectly smooth glassy tunnel with no need for concrete.

originally posted by: stormcell

originally posted by: neversaynever
Last i read. Up on that was like 8or 10 years ago. Seem like they use the stuff they bore through melt it and create nice solid glass / melted rock walls at the back as they go forward. Will we ever realy know the truth.

These tunnel boring machines had a nuclear reactor on board. The cooling system for the reactor used liquid sodium to transport the heat to the cutting end, but the other advantage of using sodium was that it would be hot enough for rock to melt as well. So the machine could melt rock where it would resolidify into glassy pebbles or slabs and they could be transported back out. All fissures and cracks in the rock are sealed, leaving a perfectly smooth glassy tunnel with no need for concrete.

That's definitely a cool idea and I'm not doubting the possibility, has anyone actually "ran the numbers" so to speak on if such a thing is even possible? I have no doubt a TBM could be built that would melt rock, but what I doubt is that it would be as easy as melting it and then just having a nice slick tunnel wall.

For example, a cutting head hot enough to melt rock is going to cause serious steam explosions underground whenever they hit a decent pocket of groundwater or water saturated rock. I'm imagining large fractures opening up in the rock getting pried open by expanding steam. Although if the gov was making these things without normal care, they might do it anyway knowing a certain percent of drillers will die, and that could explain the sinkhole situations around the country.

There is also variations in the rock itself, which would change the composition and properties of the "glass wall" the tunnel is lined with. It would be like building a bridge and not knowing what type of steel you are using.

Additionally, this would be impossible in ground with limestone, as limestone doesn't melt, it just off-gasses and turns into powder, so there would be no glassy walls to begin with. So basically you'd probably be required to find a completely pure, huge, homogeneous layer of non-limestone rock that spans for hundreds and hundreds of miles without variations. No saying it's impossible, but overall there just seems to be so many limiting factors that it seems a bit unrealistic.

I'm also thinking of cooling. The process described is basically casting stone in a way, and to avoid cracking and to get the properties of the solid material right they need to control the cooling. It would seem a logistical nightmare to control the cooling of such a large mass and size.

Plus there is still the issue of waste. All that molten rock will still have to be removed from the tunnel, as melting it doesn't get rid of it, just changes it's form. So instead of disposing of tons and tons of normal rock, which nobody would think twice about, they have to dispose of tons and tons of glass beads, or glass sheets, or liquid magma, keeping the pipes hot enough to keep magma flowing up to the surface would be a logistical nightmare too, assuming you want any living people down in the tunnel, or any functioning electronics.

I'm really not trying to poo poo the idea, I'm very open to it being possible, I'm just curious if there has been any "nuts and bolts" attempts at figuring out the logistics of such a thing.

There are three nuclear tunnel boring machine going 'Full Bore' right now over in Japan.

It'll be a little while before they'll be ready for people to actually use.

so the reactor is full of liquid sodium in which this nuclear reaction takes place?
a reply to: stormcell

You have brought up some really cool points.
a reply to: James1982

These two threads are reasonably old but, they do give some reasons why this tech will never be released to you and I. The elite want to survive.

www.abovetopsecret.com...


www.abovetopsecret.com...

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Granite explodes when heated before it melts.

Limestone breaks down into powder and very large amounts of CO2.

calcium carbonate+heat = quicklime (calcium oxide, CaO)+water =hydrated lime (calcium hydroxide, Ca(OH)2).

How do they hide the billions of tons of excess materiel.

In mining the rule is you get 1/3 expansion of materiel as its removed

broken rock takes up 1/3 more space then solid rock.

a reply to: ANNED

Yes, and excavating any form of cavern or tunnel without supporting the surroundings often results in collapse or subsidence.

I have been in hard rock mines, and have been told stories of how basically the dust, in the wrong situation, does burn. A 'secret' operation using the described system would not be all that secret. Not when you are carrying down tons of concrete/rock bolts.

So the melting rock scenario is not feasible and likewise these alleged nuclear boring machines are a myth.
a reply to: ANNED

originally posted by: Nochzwei
So the melting rock scenario is not feasible and likewise these alleged nuclear boring machines are a myth.
a reply to: ANNED

A regular TBM would work just as fast or faster in limestone.

Plus why put a reactor IN a TBM a reactor could follow a TBM on its own carriage 500 feet to a mile behind.

A liquid sodium reactor could not get hot enough to melt rock without melting its self.

It would take over 8000 degrees over the face of the tunnel to melt a tunnel in rock with any speed.

I worked on a TBM crew on the Superconducting Super Collider (SSC) tunneling job in Texas.
I know a little about tunneling.
en.wikipedia.org...
www.amusingplanet.com...

a reply to: ANNED


Yeah that is a good point, as you need heat transfer and the easiest driver of heat transfer is a temperature differential. so to heat rock, you would need the source to be a good deal hotter in order to get a reasonable rate of heat transfer to keep the rock melting at a steady pace.

The concept of heat transfer, and energy requirements for various processes are not a strong point here i must warn you. Spent 2 pages of a thread explaining some extremely simple concepts before.

Then you would have the heat that you build up cutting the tunnel that would heat the surrounding rock.

It would take days for this heat to dissipate turning the tunnel into a giant high temperature oven.

There is no way a person could survive in these temperature and no way to make repairs on equipment.

Lubrication on equipment wound burn off.

a reply to: ANNED

Not finishing the super collider was a huge bit of short sightedness
You are absolutely correct Anned,

The heat generated would take days to dissipate.

On a related side note, I had a customer that was a Lt. Cmnd USN, and a PhD in mechanical engineering. He was one of the lead engineers on a set of TBM's built for the navy. They were huge, I think they were each 600' long, they were built in tx, and shipped overseas out of Houston. It 6 months to disassemble and another to reassemble at the destination, and he wouldn't tell me where they were shipped to.
And so about 7-8 years ago there was a thread on odd seismic activity in Antarctica, someone posted an actual seismograph, and when I showed it to my customer his reaction was , someone is drilling a tunnel.