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#41
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In article , Paul F Austin
writes "Dave Eadsforth" wrote ... Jim Yanik wrote Any deep mine that had a nuclear explosion nearby deep underground would have it's shafts collapse,or become inaccessible,just as effective as destroying the WMD itself. They might even flood. At one point, it was feared that an exploding nuke could send a stream of VERY hot gasses along tunnels, thus spoiling everyone's day. However, later modelling (and maybe even testing) revealed that an underground nuclear explosion in an area containing shafts and tunnels tends to crush them flat, thus sealing them and saving the rest of the complex further damage. So, the lesson appeared to be; don't build caverns, stick to tunnels and shafts. That's interesting. Do you have a cite for that? I'm afraid not - it was described in a newspaper article many years ago, During the underground test era, in one test the blast doors failed. During a UGT, explosive-powered doors located a short distance from the bomb chamber close after the prompt radiation pulse drops off (a few hundred nanoseconds) and before the blast wave arrives, to preserve the down-hole equipment. In one test, the doors failed and the VERY hot gasses (and lots of fission fragments) both melted and contaminated the equipment in the test galleries quite far back from the bomb chamber. Was that because the blast hit the tunnel head on? If so, I could imagine the VERY hot gases etc going straight down the tube. However, if the complex were built of tunnels that zig-zagged sharply, the nuke would move enough rock to crush tunnels at 90 degrees to the explosion and any hot stuff entering a tunnel head on to begin with should be blocked when a section at 90 degrees to it collapsed. I still think that earth penetrating nuclear weapons is the triumph of "Wow, a NUKE" thinking over the realistic limits of what a nuclear weapon can do. Interesting point... Cheers, Dave -- Dave Eadsforth |
#42
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"Dave Eadsforth" wrote in message ... In article , Paul F Austin writes "Dave Eadsforth" wrote ... Jim Yanik wrote Any deep mine that had a nuclear explosion nearby deep underground would have it's shafts collapse,or become inaccessible,just as effective as destroying the WMD itself. They might even flood. At one point, it was feared that an exploding nuke could send a stream of VERY hot gasses along tunnels, thus spoiling everyone's day. However, later modelling (and maybe even testing) revealed that an underground nuclear explosion in an area containing shafts and tunnels tends to crush them flat, thus sealing them and saving the rest of the complex further damage. So, the lesson appeared to be; don't build caverns, stick to tunnels and shafts. That's interesting. Do you have a cite for that? I'm afraid not - it was described in a newspaper article many years ago, During the underground test era, in one test the blast doors failed. During a UGT, explosive-powered doors located a short distance from the bomb chamber close after the prompt radiation pulse drops off (a few hundred nanoseconds) and before the blast wave arrives, to preserve the down-hole equipment. In one test, the doors failed and the VERY hot gasses (and lots of fission fragments) both melted and contaminated the equipment in the test galleries quite far back from the bomb chamber. Was that because the blast hit the tunnel head on? If so, I could imagine the VERY hot gases etc going straight down the tube. However, if the complex were built of tunnels that zig-zagged sharply, the nuke would move enough rock to crush tunnels at 90 degrees to the explosion and any hot stuff entering a tunnel head on to begin with should be blocked when a section at 90 degrees to it collapsed. The test galleries for UGTs were layed out herringbone fashion along a main tunnel. Each test gallery could "see" the nuclear explosion so that the test articles could be exposed to both thermal and nuclear (the two blur together somewhat) radiation. The blast doors were build to withstand the overpressures that the bomb would generate. In the UGT where they failed, it was the closing mechanism that failed to operate rather than the doors being breached. As I understand it, the argument for building penetrating nuclear weapons is that the weapon will volatilize any agents (chemical or biological) that are present before they can leak out.. That seems iffy to me. As far as "crushing" tunnels, there won't be much crushing going on much outside the facture zone, which for a full yeild B61 (300KT) is about 900 feet radius. Any bunker more than a few multiples of that distance away will get a hellacious shock but if competently designed, should remain intact. Enthusiasts keep ignoring these unpleasant facts and suppose that ground-penetrating RADAR or some other MagicTech will give the attackers x-ray glasses so that they can see more or less where the bunkers really are. Fat chance. I mentioned up-thread that modern tunneling equipment can drive a shaft 200 feet a day. With a year to prepare, without superb HUMINT it's all going to be a mystery to the targeters, even with nukes at their disposal. |
#43
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In article , Paul F Austin
writes "Dave Eadsforth" wrote in message ... In article , Paul F Austin writes "Dave Eadsforth" wrote ... Jim Yanik wrote Any deep mine that had a nuclear explosion nearby deep underground would have it's shafts collapse,or become inaccessible,just as effective as destroying the WMD itself. They might even flood. At one point, it was feared that an exploding nuke could send a stream of VERY hot gasses along tunnels, thus spoiling everyone's day. However, later modelling (and maybe even testing) revealed that an underground nuclear explosion in an area containing shafts and tunnels tends to crush them flat, thus sealing them and saving the rest of the complex further damage. So, the lesson appeared to be; don't build caverns, stick to tunnels and shafts. That's interesting. Do you have a cite for that? I'm afraid not - it was described in a newspaper article many years ago, During the underground test era, in one test the blast doors failed. During a UGT, explosive-powered doors located a short distance from the bomb chamber close after the prompt radiation pulse drops off (a few hundred nanoseconds) and before the blast wave arrives, to preserve the down-hole equipment. In one test, the doors failed and the VERY hot gasses (and lots of fission fragments) both melted and contaminated the equipment in the test galleries quite far back from the bomb chamber. Was that because the blast hit the tunnel head on? If so, I could imagine the VERY hot gases etc going straight down the tube. However, if the complex were built of tunnels that zig-zagged sharply, the nuke would move enough rock to crush tunnels at 90 degrees to the explosion and any hot stuff entering a tunnel head on to begin with should be blocked when a section at 90 degrees to it collapsed. The test galleries for UGTs were layed out herringbone fashion along a main tunnel. Each test gallery could "see" the nuclear explosion so that the test articles could be exposed to both thermal and nuclear (the two blur together somewhat) radiation. So; exposed on purpose. If thin tunnels were zig-zagged like a WWI trench system with bulkheads between, I guess that might help a bit. The blast doors were build to withstand the overpressures that the bomb would generate. In the UGT where they failed, it was the closing mechanism that failed to operate rather than the doors being breached. Bet that annoyed some designer... As I understand it, the argument for building penetrating nuclear weapons is that the weapon will volatilize any agents (chemical or biological) that are present before they can leak out.. That seems iffy to me. As far as "crushing" tunnels, there won't be much crushing going on much outside the facture zone, which for a full yeild B61 (300KT) is about 900 feet radius. Any bunker more than a few multiples of that distance away will get a hellacious shock but if competently designed, should remain intact. Hmm, nuke has to be accurately targeted then - I suppose they might run to the cost of GPS guidance for this type of bomb... But the shock of the explosion would cause those bunkers safely beyond the fracture zone to rock and roll like hell. I read somewhere that the interior facilities at Cheyenne Mountain were resting on humungous sized springs - is that the only option for resilience? Enthusiasts keep ignoring these unpleasant facts and suppose that ground-penetrating RADAR or some other MagicTech will give the attackers x-ray glasses so that they can see more or less where the bunkers really are. Fat chance. I mentioned up-thread that modern tunneling equipment can drive a shaft 200 feet a day. With a year to prepare, without superb HUMINT it's all going to be a mystery to the targeters, even with nukes at their disposal. So, what to we conclude when a country orders a set of tunnelling equipment, ostensibly to build a metropolitan subway, and then gives up 'because the geology is all wrong' (um, wouldn't that have come out of the original survey?)? Is the kit sitting in a junkyard - or is it now underground, doing something else? Cheers, Dave -- Dave Eadsforth |
#44
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"Dave Eadsforth" wrote Paul F Austin writes "Dave Eadsforth" wrote Was that because the blast hit the tunnel head on? If so, I could imagine the VERY hot gases etc going straight down the tube. However, if the complex were built of tunnels that zig-zagged sharply, the nuke would move enough rock to crush tunnels at 90 degrees to the explosion and any hot stuff entering a tunnel head on to begin with should be blocked when a section at 90 degrees to it collapsed. The test galleries for UGTs were layed out herringbone fashion along a main tunnel. Each test gallery could "see" the nuclear explosion so that the test articles could be exposed to both thermal and nuclear (the two blur together somewhat) radiation. So; exposed on purpose. If thin tunnels were zig-zagged like a WWI trench system with bulkheads between, I guess that might help a bit. That's direct nuclear and thermal radiation, more or less direct line of sight. There's also the fireball, which can expand around corners. I think that if a nuke is _in_ the bunker with you, that you're in trouble. Blast doors may contain the effect but life's hard. The problem is to _get_ the nuke onto the target. Underground targeting is pretty much impossible. There are some signatures from shallow excavation but they're subject to spoofing and maskirovka. How many nuclear munitions are you going to be allowed to use in a hunt n' peck strategy? The blast doors were build to withstand the overpressures that the bomb would generate. In the UGT where they failed, it was the closing mechanism that failed to operate rather than the doors being breached. Bet that annoyed some designer... As I understand it, the argument for building penetrating nuclear weapons is that the weapon will volatilize any agents (chemical or biological) that are present before they can leak out.. That seems iffy to me. As far as "crushing" tunnels, there won't be much crushing going on much outside the facture zone, which for a full yeild B61 (300KT) is about 900 feet radius. Any bunker more than a few multiples of that distance away will get a hellacious shock but if competently designed, should remain intact. Hmm, nuke has to be accurately targeted then - I suppose they might run to the cost of GPS guidance for this type of bomb... No, it's not so much the accuracy required of the weapons as it is accuracy in target detection. From Glassstone, "relatively small, heavy, well designed structures" suffer light damage at 2 1/2 times the apparent crater radius (2200 feet in this case). This is damage to the bunker itself and not the contents. But the shock of the explosion would cause those bunkers safely beyond the fracture zone to rock and roll like hell. I read somewhere that the interior facilities at Cheyenne Mountain were resting on humungous sized springs - is that the only option for resilience? There will be two zones around a nuclear explosion: the area near the fracture zone where any bunker will collapse and and area around that where the contents of the bunker won't survive. The outside that, dust trickles out of the ceiling, everyone hunches their shoulders and then straightens up and carries on. Again, from Glasstone, internal equipment will be destroyed by a 7g shock if not shock mounted and about 60g if it is. The modelling of shocks on equipment is complex and outside a USENET discussion. Enthusiasts keep ignoring these unpleasant facts and suppose that ground-penetrating RADAR or some other MagicTech will give the attackers x-ray glasses so that they can see more or less where the bunkers really are. Fat chance. I mentioned up-thread that modern tunneling equipment can drive a shaft 200 feet a day. With a year to prepare, without superb HUMINT it's all going to be a mystery to the targeters, even with nukes at their disposal. So, what to we conclude when a country orders a set of tunnelling equipment, ostensibly to build a metropolitan subway, and then gives up 'because the geology is all wrong' (um, wouldn't that have come out of the original survey?)? Is the kit sitting in a junkyard - or is it now underground, doing something else? North Korea for instance doesn't even pretend to be building subways. They've been tunneling for fifty years and the area near the DMZ (and under it) is honeycombed with tunnels. This is a hard problem and one that the puissance of nuclear weapons doesn't solve. |
#45
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"Dave Eadsforth" wrote in message ... So, what to we conclude when a country orders a set of tunnelling equipment, ostensibly to build a metropolitan subway, and then gives up 'because the geology is all wrong' (um, wouldn't that have come out of the original survey?)? Is the kit sitting in a junkyard - or is it now underground, doing something else? For deep hard rock mining you use drilling and blasting techniques (commercial explosives and BIG drills). This is how the South African gold mines extract over 130 million tons of rock (and gold ore) every year from as deep as 4km (2.5 miles) - with plans to go deeper in future. Modern tunnelling equipement as you discuss only work in soft rock. So you would have to stop anyone who has access to simple commecial explosives - which is simple to manufacture. Da vid |
#46
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In article , "Paul F
Austin" wrote: North Korea for instance doesn't even pretend to be building subways. They've been tunneling for fifty years and the area near the DMZ (and under it) is honeycombed with tunnels. Perhaps if that part of the world calms down, and even reunifies, Korea will become the dominant world power in mushroom farming. |
#47
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"Who do you drop a nuclear bunker buster on?"
Any greasy, finger-eating Arab I can plop my thermonulear greeting card on. Tetherhorne P. Flutterblast |
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