[40k] Calcing the LeMan Russ
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Winston Blake
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Connor MacLeod
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Well, as I mentioned, krak GRENADES (something either tossed by a man or fired from a grgenade launcher) cna arguably be in the gigajoule range as per the Soul Drinkers novels. We know other anti-tank weapons (meltaguns and multimeltas, but also possibly heavier plasma guns and lascannons) are also arguably gigajoule range as well, so having a shaped charge blast that punches out a large number of gigajoules is not entirely inconsistent.
I'm not sure I'd neccesarily call it "nuclear" yield, though I understand some smaller explosives (especially the closest to man portable) would have similar yields. However, we know 40K has some devices, explosives, and whatnot with extreme energy densities (Promethium, whatever they use in meltabombs, and meltaguns.) so I'm not really concerned about this (any more than I am about thermal detonators or protorps.)
As for the other idea that its a kinetic impactor of some kind, I already mentioned the idea that it could be rocket propelled (the idea of rocket propelled cannons is addressed in a number of sourcecs. With a little fudging it might allow for the sort of extreme velocity you talk about (though I'm not sure how efficient it would be in terms of energy usage.)
As for the HESH round, I think they have those but they might be a specialized/rare variant (due to Imperial Armour at least.) and I think they aren't "armor piercing" which is what the quote implies.
As for the "omnidirectional explosion" idea, the only way to work that out is probably to take the total force applied to the tank and divide it by the surface area of said tank (~4.4 meters tall and ~7 meters long, IIRC.)
Taking your 2.5e5 Ns figure from before, that might be at least 5 psi. I'm still digging for calcs that might allow something to be figured. I'm trying to work something from stuff on Mike's page (I was hoping th enuke effects calclatoru might help.)
One "quick and dirty" way to do it might be to work with 'detonation velocity" and the mass of explosive to be vaporized/accelerated. Assuming a ~8 km/s detonation velocity (about what TNT has, IIRC) divided by the momentum yields something around ~31.25 kg of "mass".
That yields ~ 1 GJ of energy (equal to about 250 kilos of TNT). Of course, ,the blast is "omni-directonal" so the blast is actually going to be no less than half the total, meaning its at least 2 GJ (and 500 kg of TNT, roughly) All in about ~60 kg shell, tops. Not quite as "insane" as your calcs, but still pretty nasty.
On the other hand (and I think this might be one reason why you initally ignored the idea - its one reason I do) I think that an omnidirectional blast is stretching the description. Moreover, the amount of collateral damage that might well be inflicted near a habitable area (like a town, or a forest) is probably a non-insignificant issue (and as I recall, there were also troops out in the open.)
Moreover, that would imply a fragmentation/HE shell, whcih are mainly against light vehicles and personnel, not an armoured tank.
I'm not sure I'd neccesarily call it "nuclear" yield, though I understand some smaller explosives (especially the closest to man portable) would have similar yields. However, we know 40K has some devices, explosives, and whatnot with extreme energy densities (Promethium, whatever they use in meltabombs, and meltaguns.) so I'm not really concerned about this (any more than I am about thermal detonators or protorps.)
As for the other idea that its a kinetic impactor of some kind, I already mentioned the idea that it could be rocket propelled (the idea of rocket propelled cannons is addressed in a number of sourcecs. With a little fudging it might allow for the sort of extreme velocity you talk about (though I'm not sure how efficient it would be in terms of energy usage.)
As for the HESH round, I think they have those but they might be a specialized/rare variant (due to Imperial Armour at least.) and I think they aren't "armor piercing" which is what the quote implies.
As for the "omnidirectional explosion" idea, the only way to work that out is probably to take the total force applied to the tank and divide it by the surface area of said tank (~4.4 meters tall and ~7 meters long, IIRC.)
Taking your 2.5e5 Ns figure from before, that might be at least 5 psi. I'm still digging for calcs that might allow something to be figured. I'm trying to work something from stuff on Mike's page (I was hoping th enuke effects calclatoru might help.)
One "quick and dirty" way to do it might be to work with 'detonation velocity" and the mass of explosive to be vaporized/accelerated. Assuming a ~8 km/s detonation velocity (about what TNT has, IIRC) divided by the momentum yields something around ~31.25 kg of "mass".
That yields ~ 1 GJ of energy (equal to about 250 kilos of TNT). Of course, ,the blast is "omni-directonal" so the blast is actually going to be no less than half the total, meaning its at least 2 GJ (and 500 kg of TNT, roughly) All in about ~60 kg shell, tops. Not quite as "insane" as your calcs, but still pretty nasty.
On the other hand (and I think this might be one reason why you initally ignored the idea - its one reason I do) I think that an omnidirectional blast is stretching the description. Moreover, the amount of collateral damage that might well be inflicted near a habitable area (like a town, or a forest) is probably a non-insignificant issue (and as I recall, there were also troops out in the open.)
Moreover, that would imply a fragmentation/HE shell, whcih are mainly against light vehicles and personnel, not an armoured tank.
