david@randvax.UUCP (David Shlapak) (10/05/84)
------- A question has been raised about just what it takes to "destroy" a city with nuclear weapons. While the answer to this query is highly dependent upon what one means by "destroy," there are some reasonable outlines of an answer that can be provided. The city of Leningrad, for example, has an area of ~193 square miles. A 40-kt weapon exerts an overpressure of 5 psi over an area ~2.25 square miles, 5 psi being the commonly accepted value for destruction of a normal non-reinforced structure. Thus, ~10 40-kt airbursts would be needed to achieve a high level of damage. "The Day After Midnight," a popular tome based upon an OTA report, has a good exposition of this very case. David Rubin's assessment that "a single 250 kiloton weapon would level any city"is patently absurd. A 250-kt bomb detonated over, for example, Wall Street, would have virtually no direct effect on Brooklyn. If Wrigley Field were targeted by some irate Padres fan on opening day next year, customers at Comisky Park on the South Side might not even notice until they left the game and found that some CTA trains weren't running... Also, Rubin's point that "one 40 kiloton bomb will end any city's economic and military usefullness (sic)" is off target in several ways. First, if we're talking about "city-busting" we're no longer in the realm of worrying about the military utility of the target; we are in the business of inflicting pain and punishment (cf Thomas Schelling's "Arms and Influence"). Thus, we want to do more than knock down power lines and break gas and water mains...we're looking for destruction. As outlined above, it takes a lot more than 40 kt to destroy a city of any size. If, however, you're talking about attacking a city because it happens to be co-located with a military target of some interest in a counterforce strike of some type, larger and more numerous weapons will e needed simply because such targets tend to be harder and demand a much higher level of destruction in order to be neutralized. Either way, "one 40 kiloton bombs" will not suffice for the task. Rubin also states: >Two 40 kiloton bombs, placed at >opposite ends of town, can do more damage than a single 250 kiloton >bomb (though admittedly would not produce as much fallout). Well, it all depends...weapons' effects is not as exact an art as you appear to believe. The amount of "damage" caused by two 40-kt weapons compared to a single one of 250-kt will depend, among other things, upon: 1. The size of the city 2. The architecture and terrain of the city. 3. The reason you're attacking the city 4. The weather 5. Whether the weapons are ground- or air-burst 6. The accuracy of the weapons 7. The reliability of the weapons 8. What you mean by "damage." The amount of fallout produced is almost entirely a function of point five. Two 40-kt weapons ground-burst will produce much more fallout than a single 250-kt air-burst. All in all, this flat assertion is a tad simplistic. Again, "The Day After Midnight" would not be a bad place to start to pick up a little more weaponeering; if you're ambitious, the Department of Energy's volume "The Effects of Nuclear Weapons" (available at any GPO bookstore) is even better. >Thus, it is apporpriate to divide the number of >Poseiden warheads by two rather than six to twenty in calculating how >many cities would be destroyed. I hope that the above makes clear that this statement is spurious. Now, a comment from another keyboard, that of Milo Medin: >6 bombs detonated at the same spot and the same time??? >Come on now, I realize you are familiar with fuzing mechanisms >but common sense should tell you something is wrong with that >idea. Since my heading of "Strategic Arms: Reply to Tim Sevener" is being used to cover a multitude of sins, I don't know who precisely this passage is addressed to. However, I will respond to wit: timing of detonations over cities is hardly critical. Fuzing mechanisms really have nothing to do with it. The need for precise coordination and timing in a "first-strike" type counter-force attack is extremely high, for a variety of reasons, none of which will I go into (although I recall a "Scientific American" piece earlier this year that did a not-bad job of explaining some of them); when it comes down to cities, however, those requirements disappear. You can detonate those suckers tens of minutes apart (an eternity in terms of the timing reqiuirement for, say, silo attacks) without any appreciable loss in effectiveness. Also note that, as the preceding argument should make clear, in attacking a city one would not necessarily be detonating a number of weapons "at the same spot;" in fact, such targeting would be counterproductive. To destroy a big city one would NEED to explode the weapons miles apart. Yours in the interest of informed discoures, --- das
medin@ucbvax.ARPA (Milo Medin) (10/14/84)
Of course you are entirely correct, I was not advocating such a strategy, but merely stating that Rubin's method of attack is unlikely to succeed. All your points regarding countervalue attack are very valid. 40kt is just not enough to do the job. Milo