From: utzoo!decvax!ucbvax!C70:arms-d Newsgroups: fa.arms-d Title: Arms-Discussion Digest V0 #136 Article-I.D.: ucb.1458 Posted: Fri Jul 2 13:44:38 1982 Received: Sat Jul 3 05:18:14 1982 >From HGA@MIT-MC Thu Jul 1 22:29:20 1982 Arms-Discussion Digest Volume 0 : Issue 136 Today's Topics: Spare Parts & Maint The Utility of Big Carriers US defenses ---------------------------------------------------------------------- Date: 1 Jul 82 17:05:23-EDT (Thu) From: Earl Weaver (VLD/VMB)Subject: Spare Parts & Maint These comments are to shed a little light on the spare parts/maintenance problem the armed forces have. First of all, the decision of what parts to keep for spares depends on whether or not combat is involved. Most of the data base for such things is based upon peace time wearout. We know how many hours an aircraft engine is capable of functioning before it is considered unsafe without overhaul. Likewise we know how often to change oil and change spark plugs, etc. (BTW, the average battle tank can go 6000 miles before a complete overhaul is needed. The average soviet tank cannot go as far before similar repair is needed; that is why they haul their tanks around on tank carriers.) [I cannot site references other than discussions with tankers and maintenance personnel whom I believe because of their experience.] I once heard that combat commanders requisition spares based upon five times the normal peacetime wearout. Obviously, the problem with that approach is that in combat, things not only wear out, but get shot off. Many components of weapons systems really don't wear out, thus there is no need for too many spares for such parts. An other problem is that some parts age; if stockpiled they'll just go to waste. The Army has been attemping to get a good handle on the spare parts problem as well as the maintenance problem. The sample is relatively small for combat damage. The Israeli conflicts have been valuable (?!) in this regard since US M-60s were involved. The problem boils down to solving the problem: given a scenario in which we expect some munition to be used against a set of given materiel, what is the probability of damage to a specified part, given a hit. Vulnerability analysis (analytical) is being used to attack the problem, but the path is not simple. The maintenance problem is also related to vulnerability. Unfortunately, ease of maintenance and the vulnerability of materiel are related in that usually if a piece of equipment is easy to maintain (repair) it is usually easy kill (or disable to the point of not being able to complete its mission). Design goals include exercises of placing 'critical' components in positions such that they are shielded by non-critical components; it is impractical to armor every component in a weapon system--it would be so heavy it could not move! Thus, by making the materiel less vulnerable the penalty is often a mechanic's nightmare. War machines are not like commercial vehicles [although from some of the ones I've worked on you'd think the engineers placed components expecting combat!]. The idea of bolting armor on a tank sounds good, but in today's battle field, the armor would just get blasted off (possibly by munitions that would otherwise not affect the tank). Blast and shock from high energy projectiles are really destructive. I saw a picture once of an M-48 tank that was hit in the turret (without blowing it up) and the shock was so fierce the main gun tube [those military types don't call it a barrel] broke off about a foot out from the turret. ------------------------------ Date: 1 Jul 82 14:36:51 EDT (Thu) From: Steve Bellovin Subject: Re: The Utility of Big Carriers What's the range of a modern anti-ship cruise missle? 300 miles? Whatever the figure is, it's sure to improve dramatically in the near future, especially if it's equipped with a satellite-based navigation system. My feeling is that the total cost of a carrier battle group -- the destroyers, the submarines, the copters, everything else -- is far too high to be worthwhile. As you point out, almost all of its resources are devoted to protecting the offensive power of *one* ship. For the same money and crew, we could probably deliver more military power with other configurations. Furthermore, such a battle group would have far greater survivability -- it wouldn't be helpless if it lost the carrier. ------------------------------ Date: 1 Jul 1982 1851-PDT From: Jim McGrath Subject: Re: US defenses I don't think Canada will literally go the way of Cuba - but there is real danger of fragmentation and extremists seizing power in that nation. I don't think absorbing Mexico would adversely affect our security - as long as such absorbtions were gradual, I feel sure that our good old federal government would "level" the new territory, making it richer and politically more stable. A different perspective is perhaps involved here - it might seem strange to people in the northeast that we could absorb Mexico, but from the Southwest the situation is different. Ultimately I think the US should expand simply because we have the best system of government currently available on any respectable scale. I am sure that South Americans would generally appreciate the wealth and stability they would secure if only they were treated as equal partners in governing. Jim ------------------------------ End of Arms-D Digest ********************