The deepest bunker of them all

[Purple]

Alright SF fans, here is an interesting question for you. Say I wanted to use advanced technology of the future TM to build a bunker as deep as I possibly could on a planet. How far could I reasonably go before it ends up sounding idiotic? I assume that the limit is where the crust ends, or perhaps somewhere down in the mantle but I have no idea really.

The design goal would be a bunker that can survive a BDZ operation without issues.

[Mr Bean]

Alright SF fans, here is an interesting question for you. Say I wanted to use advanced technology of the future TM to build a bunker as deep as I possibly could on a planet. How far could I reasonably go before it ends up sounding idiotic? I assume that the limit is where the crust ends, or perhaps somewhere down in the mantle but I have no idea really.

The design goal would be a bunker that can survive a BDZ operation without issues.

The short answer is "on a different planet entirely"
But yes even with super advance science your going to talk about anything deeper than the crust is silly since anything strong enough to survive under the crust in the mantel you might as well want to make a planetoid out of in space somewhere. Anything deeper than 2 KM's means your going to boil alive if your super bunker losing heat shielding. And yes the crust is over 40 KM's thick in some places so you want to find a nice old mountain range and dig down from there about three kilometers then dig up for as much armor as you want to place, say you want to put in 100 meter thick shielding of SpaceSteel(tm). Your bunker should be year round at around 90*F that far down which means its survivable but not conformable without active cooling. Every KM after the first one increases your heat factor by over 70*F or 25*C per Kilometer.

The problem is that a BDZ SW event is designed to crack the crust on the planet and cause massive earthquakes/deadly outgassing and generally cover the entire planet in super hot magma. If your bunker survives this even it's literally going to need to dig itself out, unless the entrance is itself as reinforced as the bunker itself it's going to fail and you'll be left in a deep underground bunker with millions of tons of rock above your head.

So in essence you need a bunker that's also has the ability move underground IE a ship of some sort. In short for a BDZ event you can build kilometer deep shelters and hope for the best that people might be able to survive for a few weeks underground in the even of a BDZ but then die anyway trapped alone underground.

[Purple]

Thanks for the reply. Now to start off with quoting it and hopefully collaborate my way to a solution.

The short answer is "on a different planet entirely"
But yes even with super advance science your going to talk about anything deeper than the crust is silly since anything strong enough to survive under the crust in the mantel you might as well want to make a planetoid out of in space somewhere.

That is in a way what happens. The bunker would have at least 1-2 kilometers worth of solid armor material, the kind SW uses for starships and it will be completely sealed so that it can survive if the planet is blown up around it.

In fact, the original design idea I had was for a bunker that would survive a planetary destruction (not Death Star type, but the much less energetic kinds) and remain standing. Than it would use FTL engines to escape.

Anything deeper than 2 KM's means your going to boil alive if your super bunker losing heat shielding. And yes the crust is over 40 KM's thick in some places so you want to find a nice old mountain range and dig down from there about three kilometers then dig up for as much armor as you want to place, say you want to put in 100 meter thick shielding of SpaceSteel(tm). Your bunker should be year round at around 90*F that far down which means its survivable but not conformable without active cooling. Every KM after the first one increases your heat factor by over 70*F or 25*C per Kilometer.

So add massive cooling plants got it. This said, here is an idea. What if the bunker was so huge that it encompasses it's own aquifer that is kept frozen during normal operation but in cases of emergency can be used as backup cooling fluid?

The problem is that a BDZ SW event is designed to crack the crust on the planet and cause massive earthquakes/deadly outgassing and generally cover the entire planet in super hot magma. If your bunker survives this even it's literally going to need to dig itself out, unless the entrance is itself as reinforced as the bunker itself it's going to fail and you'll be left in a deep underground bunker with millions of tons of rock above your head.

Well as said above. The idea is that it just waits for allies or the enemy to blow the world away around them and jumps away on it's own power. In theory at least.

So in essence you need a bunker that's also has the ability move underground IE a ship of some sort. In short for a BDZ event you can build kilometer deep shelters and hope for the best that people might be able to survive for a few weeks underground in the even of a BDZ but then die anyway trapped alone underground.

So make my bunker into a proper buried starship. That does not sound too hard to justify.

[Sarevok]

Easy solution ?

Take an Accamalator assault ship.

Dig a deep tunnel with HTLs, then bury said ship into the tunnel.

Keep reactor running and divert all power to shields.

The ship was built to take direct hits from HTLs so it should be able to weather a BDZ operation just fine.

[Serafina]

The idea of actually making the bunker mobile (as in "can dig itself out and fly away") is very viable - as Mr. Bean said, you really don't want to hang around on a planet that has suffered a BDZ.

At the very least the bunker should be one solid complex that can be dug out of the crust, by external help if necessary.

[Eulogy]

If you have Super Science, it'd be better to move the entire surface of the planet plus atmosphere somewhere else like another dimension or planet. It's hard to get your shit ruined if you're not there.

[Whiskey144]

Easy solution ?

Take an Accamalator assault ship.

Dig a deep tunnel with HTLs, then bury said ship into the tunnel.

Keep reactor running and divert all power to shields.

The ship was built to take direct hits from HTLs so it should be able to weather a BDZ operation just fine.

While the OP does mention "BDZ", I assume that he meant, oh, BDZ-like, not actual SW BDZ. Which makes your whole post kinda useless, and not a little bit ridiculous. It also sounds rather implausible in the context of even SW.

In response to the OP, I'd say that everything you've said so far seems pretty good to go.

[Sea Skimmer]

8-12,000 deep deep has actually been proposed in real life. No possible depth of rock will protect you from a sustained 200 gigaton bombardment. Bean is right, you basically would need a shielded ship that can move underground to avoid repeated hits on the same spot or else a planet made of tungsten.

[Purple]

Alright, plan B than. I will post a short description of what I made up based on your input so far and you tell me how you think it will perform.

The bunker is a massive self contained entity buried about 10-12 kilometers under the surface. It's protection include heavy duty shielding and about 80% of said dept (in all directions) being filled not by dirt and rock but by SW style armoring materials. The bunker has complete internal life support in the form of an internal minimal ecosystem (trees and a lake) to produce oxygen and a massive power generator to supply cooling and power to the shields and run emergency oxygen recycling plants. The internal space is several kilometers wide in all directions and almost a kilometer tall.

How does that sound?

[lordofchange13]

Just build a forerunner shield world. There a partially hollowed out planet, that holds a pocket reality, you have now survived a BDZ, and possibly a Death Star blast!

[Mr Bean]

Alright, plan B than. I will post a short description of what I made up based on your input so far and you tell me how you think it will perform.

The bunker is a massive self contained entity buried about 10-12 kilometers under the surface. It's protection include heavy duty shielding and about 80% of said dept (in all directions) being filled not by dirt and rock but by SW style armoring materials. The bunker has complete internal life support in the form of an internal minimal ecosystem (trees and a lake) to produce oxygen and a massive power generator to supply cooling and power to the shields and run emergency oxygen recycling plants. The internal space is several kilometers wide in all directions and almost a kilometer tall.

How does that sound?

Like you need internal dampeners something fierce. Also it's going to sink. You can't put a super massive giant egg into the ear and not expect it to sink. In fact at that depth the constant interaction between the water table flash into steam is going to very quickly(In weeks) weaken the surrounding rock and your entire bunker is going to start listing. Made worse by the super dense and super heavy SW style shielding materials. Before you bunker is even done being constructed it's going to start sinking like a brick. Trying to do some back of the napkin calculations that results in a weight over over 94,164,000,000 kilograms or over 103 million tons if you were using something as heavy as steel (And SW materials weigh more) and that's only back of the napkin, going with your predicted armoring value ups that by three full magnitudes or over ninety billion plus tons worth of armoring contained in one area. And I might be off by as much as 2000% depending on the materials used and the internal construction of the bunker.

What's going to happen is your bunker is going to break up the surrounding rock and sink before it's even constructed or within a week or two assuming a standard earth gravity.

[Purple]

Oh... wow. I was expecting some stuff but not this. Well, than off to plan C. Well, as soon as I figure something out for plan C.

[Sea Skimmer]

Alright, plan B than. I will post a short description of what I made up based on your input so far and you tell me how you think it will perform.

The bunker is a massive self contained entity buried about 10-12 kilometers under the surface. It's protection include heavy duty shielding and about 80% of said dept (in all directions) being filled not by dirt and rock but by SW style armoring materials. The bunker has complete internal life support in the form of an internal minimal ecosystem (trees and a lake) to produce oxygen and a massive power generator to supply cooling and power to the shields and run emergency oxygen recycling plants. The internal space is several kilometers wide in all directions and almost a kilometer tall.

How does that sound?

WTF is the point of burying it in a planet at all if it has 8km of armor plate all around it? Just build an orbital battle station for FAR LESS effort and superior protection because the rock will actively tamp blast against you, while the void of space does not. The bunker sinking can be solved with enough anti grav, and frankly that's a minor problem compared to the effort required to build the thing in the first place. If you really really want, then at least find a nickel-iron asteroid of some size and bury the bunker inside of that. Or even squish chunks of iron asteroid around the battle station.

[SpaceMarine93]

Why waste resources on a bunker when you can simply flee to another planet? And even if the bunker survives the BDZ operation, which is essentially a Star Wars version of an Exterminatus, how do its occupants get off the planet afterwards when its crust is molten?

First, If you have to build a bunker that could survive a BDZ, build it somewhere the attackers would not consider to be a center of resistance or a major strategic site. Given the scale of the attack, you would not want to have a massive orbital blast landing directly on your head. Even it denoted the most severe of several levels of destruction that could be directed against a center of resistance and kill everyone, they would still first target areas of high strategic value like any good bombardment sortie, so build your bunker away from areas such as resistance strongholds, planetary infrastructure, industries, high population areas, natural resource areas etc. Probably at a mountain range in a part of the planet which nobody goes anyways.

Second, remember that this BDZ involves laying waste to an entire planet by orbital bombardment, reducing the upper crust of a planet to molten slag. Like every previous replies by other people, put as much crap on top of you as possible. Consider the Russians at Yamanatu - they build their Cold War Doomsday Bunker BENEATH a mountain, with over 6,000 feet of naturally hardened quartz-laced granite on top. In this case, build it underneath the tallest mountain range composed of the hardest of substances, and build as deep as the lower crust.

Third, Hoth strategy - prevent the attacker from doing so in the first place. In "The Empire Strikes Back", the Rebel Alliance prevented the Imperials from using orbital bombardment by a combination of a massive Planetary Defense Shield and Ion cannons. Since the Imperials on Hoth deployed troops to remove both obstacles, modify the shield a bit so that instead of one installation the devices are spread out across the planet in well hidden / well defended places. And make sure the planet, or at least those areas of the planet, are totally inhospitable places with horrible terrain and weather that would severely limit the attackers advantages.

Fourth, if point 3 didn't work, put as much shields in form of deflector shields or armor on top of your bunker as possible, with the most advanced armor technology available. Also, make sure you have some ways to leave the planet after the bombardment is over.

By the way, why BDZ when the attacker could simply Death Star you?

[Sarevok]

While the OP does mention "BDZ", I assume that he meant, oh, BDZ-like, not actual SW BDZ. Which makes your whole post kinda useless, and not a little bit ridiculous. It also sounds rather implausible in the context of even SW.

In response to the OP, I'd say that everything you've said so far seems pretty good to go.

Dude surviving energies involved in melting a planets surface is small cake for any ship built to take hits from such weapons. Just replace the Accamalator with any in-atmo capable shielded starship. Heck even a Covenant CCS Battlecruiser if you like because that too could pull off the job of surviving a planetary slagging operation by hiding deep. It might be able to weather it even while sitting on the surface because sustainted direct hits are required to bring down the shields. Distant bomardment that is heating up the planet would bare inconvenience the shield generators.

[madd0ct0r]

you could try a tectonically dead world. less issue from heat and magma as you go down.

presumably a BDZ dosen't work either as there's no magma to spill beneath the crust.

[Raxmei]

By the time you're talking about riding out a BDZ you aren't so much using the planet's crust for protection as for concealment. BDZ's going to wreck the rock around you but unless they know there's a hardened structure there they won't know to put extra fire on you to take you out.

[Purple]

By the time you're talking about riding out a BDZ you aren't so much using the planet's crust for protection as for concealment. BDZ's going to wreck the rock around you but unless they know there's a hardened structure there they won't know to put extra fire on you to take you out.

That is a good point. As for the others, sadly I am unable to put this thing under a mountain and stuff like that. This is becouse it is supposed to be a panic room for my government and therefore has to be within shouting distance of the capital city that is in a plain. So I will just make it the equivalent of a super armored starship and just conceal it inside the planet and hope for the best.

[Jawawithagun]

By the time you're talking about riding out a BDZ you aren't so much using the planet's crust for protection as for concealment. BDZ's going to wreck the rock around you but unless they know there's a hardened structure there they won't know to put extra fire on you to take you out.

Any glance at the seismics will tell you it is there.

[keen320]

From the size you were talking earlier...

Alright, plan B than. I will post a short description of what I made up based on your input so far and you tell me how you think it will perform.

The bunker is a massive self contained entity buried about 10-12 kilometers under the surface. It's protection include heavy duty shielding and about 80% of said dept (in all directions) being filled not by dirt and rock but by SW style armoring materials. The bunker has complete internal life support in the form of an internal minimal ecosystem (trees and a lake) to produce oxygen and a massive power generator to supply cooling and power to the shields and run emergency oxygen recycling plants. The internal space is several kilometers wide in all directions and almost a kilometer tall.

How does that sound?

Like you need internal dampeners something fierce. Also it's going to sink. You can't put a super massive giant egg into the ear and not expect it to sink. In fact at that depth the constant interaction between the water table flash into steam is going to very quickly(In weeks) weaken the surrounding rock and your entire bunker is going to start listing. Made worse by the super dense and super heavy SW style shielding materials. Before you bunker is even done being constructed it's going to start sinking like a brick. Trying to do some back of the napkin calculations that results in a weight over over 94,164,000,000 kilograms or over 103 million tons if you were using something as heavy as steel (And SW materials weigh more) and that's only back of the napkin, going with your predicted armoring value ups that by three full magnitudes or over ninety billion plus tons worth of armoring contained in one area. And I might be off by as much as 2000% depending on the materials used and the internal construction of the bunker.

What's going to happen is your bunker is going to break up the surrounding rock and sink before it's even constructed or within a week or two assuming a standard earth gravity.

Would that be big enough to show up as an anomaly on gravitic sensors? Doesn't GFFA have stuff like that?

[Whiskey144]

Dude surviving energies involved in melting a planets surface is small cake for any ship built to take hits from such weapons. Just replace the Accamalator with any in-atmo capable shielded starship. Heck even a Covenant CCS Battlecruiser if you like because that too could pull off the job of surviving a planetary slagging operation by hiding deep. It might be able to weather it even while sitting on the surface because sustainted direct hits are required to bring down the shields. Distant bomardment that is heating up the planet would bare inconvenience the shield generators.

Completely Missing the Point

I wish the original version of that page was still around, as it'd make more sense. Anyways, my point was that Purple isn't talking about Star Wars, he's talking about a setting he's working on himself. Hence, you completely missed the point by suggesting Star Wars solutions to a problem that, while probably shared by SW, is not being discussed in relation to SW.

Further, as is quite possible in SW, ships may be using far lower power shots in combat than their guns can fire, in order to have a useful combat endurance under normal conditions, especially considering some of the fuel consumption rates given in the ICSes (40,000 tonnes/second for a Venator!). This could similarly apply to other settings/series, though more likely to be for different reason, such as maintenance or ammunition supply.

I will also note that I dislike all things Halo.

Would that be big enough to show up as an anomaly on gravitic sensors? Doesn't GFFA have stuff like that?

As above. Purple is not talking about Star Wars in particular, but rather his own setting.

[Sarevok]

It might even be big enough to be detectable via real world analysis of mass concentrations. The lunar mascons were detected using 1960s satellite technology. Today we have satellites so sensitive that their mission is to prove the very existence of gravitational waves.

[Simon_Jester]

Many of the components of the Star Wars soft-SF setting are available in other settings. Lots of settings, very likely including Purple's, will have things like shields, gigaton-range weapons capable of laying down a very devastating carpet-bombing of a planetary surface in a short time, and sensors easily capable of picking out billion-ton masses of metal from a planetary crust, not like that's difficult.

Moreover, it's not like Purple has actually supplied us with the details of his own setting, so describing the possible measures and countermeasures available in terms of a known setting is about the best we're going to be able to do. Translating that into concepts feasible in his setting, with whatever technology he thinks should be available, is very much his job.

[khursed]

My point of view.

I assume a civilisation facing a possible DBZ operation has got to be on par technologically speaking.

In this case, lets work on the assumption that you are using similar capacity against a potentially devastating attack that you only have moments to react to.

First of all, I would think in such a case, your best protection would be secrecy, I know people will not give it much thought, but I believe that the best defense is hidden ability, however puny they are, for the unknown is always the most dangerous factor in any battle.

So, assuming your planet manages to construct in secret such a defensive position, the fact that the ennemy is unaware of it would probably be its greatest strength.

Case in point, Cheyenne mountain, heres a lot of info that may help you. http://en.wikipedia.org/wiki/Cheyenne_mountain

The military planners first figured the accuracy of soviets icbm would be such that the base was virtually indestructible. However, further intel presented the military with the evidence that their assesment had been overly optimistic.

The truth of the matter is, if your ennemy know about your base, it might be impracticle to expect to build a liferaft-bunker that will escape destruction. You might survive the innitial blast, however something tells me the ennemy would having leveled your planet, simply take the time to dig you out, to do otherwise knowing you are there would be pretty stupid.

So, assuming you manage to build it in total secrecy, then we can begin the hard work, for next comes stealths.

Hidding a spaceship in space, or a heavily fortified battle station around your planet is next to impossible unless you use some form of "cloaking technology" a la star trek. Or if ya do SW style, it is my understanding that cloaking makes you blind.

This doesn't mean you can't use various natural features of your planet to hide your bunker, also of great importance is to best use whats available, for instance on a terraformed planet with no active core, no plate tectonics, no melted interrior, you could possibly dig extremely deep.

The entrance to your bunker, one of them anyway, might be close to your leader's capital, however it doesn't mean you can't include super fast underground travel, I was reading about hyper-fast trains in deep underground tunnel traveling in airless tubes. I'm sure if our current models say we could in theory build mach 8-10 fast trains in those conditions, then your highly advance civilization could probably do even better by an order of magnitude or better. I don't know about you, but going at mach 100 has got to get anywhere mighty fast on any planet. That's close to 20 miles per seconds, so given a single minutes drive, you are 1200 miles away, which should provide for a good way to hide your actual bunker far from prying eyes.

If it were me, I would probably build it a mile or so under a deep oceanic trench, that way the water above can act as a huge shock absorber for the devastation unleashed, hopping they don't vaporise the ocean, I'll leave it up to your preference, and according to the "enemy's" capacity. If they can actually vaporize oceans, then you will probably need some huge mountain range and dig deep.

Something to consider, using really advanced building material, if you can make a bunker able to withstand the sheer pressure of the weight above it, and use a system to resist shock waves, then what you really need, is simply some good inertia compensating device, like they seem to have on all advance ships, to survive the pounding, and a method of escape after said pounding.

You can also nullify a lot of the shock wave with current technology, added with advanced material you could conceivably build a bunker really deep, built to withstand incredible weight that could offer very high odds of survival, depending on what you want to survive.

The main thing will be to figure out exactly what it is you are trying to survive, for example if they simply blanket the planet with 200 gigatons bombs every square kilometer, that's a viable way of killing about everything. Next would they actually use burrowing bombs? I would imagine air blast would be best to destroy land building, however if they suspect a lot of heavy building buried deep underground, they might use weapons that actually penetrate deep to destroy those.

Before you build the bunker, you will need to face all those questions.

Good luck.

[Mr Bean]

Note khursed, it's BDZ not DBZ, BDZ is a SW term for "Base Delta Zero" a Naval code word for the destruction of a planets crust to expose the mantel. Depending on the serverity your talking about a total extinction event for a few hundred years or a few million. Focusing high energy weaponry into a worlds fault lines and existing weak points to trigger massive earthquakes plate disruption, world wide firestorms. The higher level forms of BDZ seek to liquidate the entire crust.