dwells@fits.cx.nrao.edu (Don Wells) (10/24/90)
From: dwells@fits.cx.nrao.edu (Don Wells) In article <1990Oct19.033435.14863@cbnews.att.com> fmrco!curt@uunet.UU.NET (Curt Fennell) writes: ... As far as artillery is concerned, unless an artillery round lands directly on the tank, the tank armor will protect the crew against the primary effect of artillery, which is shrapnel (sp?). The odds on an unguided artillery round hitting a tank directly are very small, and remember that tanks can move out from under an artillery barrage fairly quickly. Most artillery is still of the HE variety and regular steel tank armor is more than sufficient for anything other than a direct hit. When I was a student at the armor school, they told us that our M60 tank armor was proof against the effects of 90% of the weapons on the battlefield. A misleading statistic, to be sure, but the point was made. Still, artillery can degrade the effectiveness of tank units by forcing the crew to 'button up' and by stripping off radio antennas and other outside equipment. But the actual destruction of tanks is best left to other tanks. ... Last summer, while on a trip, I was heading east on I10 in LA, and turned north at Slidell,LA, onto I59. Within a few miles I59 crosses into Mississippi, and just over the border one encounters an exit to the NASA John Stennis Spaceflight Center, which is NASA's rocket engine test facility. I decided to spend an hour touring NASA's museum at the center (it is fairly interesting; I didn't have time to tour the engine test stands and so can't comment on them). But, in the context of this newsgroup, the relevant item is that located on that NASA base is a US Army facility, an ammunition factory. You pass by it on the road from I59 to the NASA buildings. In the NASA museum there is a display about the Army factory. I was surprised to find that it is a highly automated factory whose function is to manufacture a particular kind of 155mm artillery shell. Sorry, I don't remember the model number. The shell contains small bomblets. My memory is that they were of order 40-50mm in diameter, perhaps 80-100mm long. They have a cloth "tail" on them, kind of like a kite tail. The bomblets, as I call them, are *shaped charges*. The 155mm shell body contains a considerable number of them, several dozen at least. The tip of the 155mm shell contains a modest explosive charge. The concept is that as the shell descends near the target area at a certain height (100m or so?) the charge is fired. The base of the shell (which is now the top of the descending shell, of course) pops open, and the charge pushes the swarm of bomblets backwards into the air, dispersing them radially to some extent, of course. They decelerate and their tails deploy, which quickly orients them vertically, with their shaped charges downward, and they fall to earth -- or armored things -- at a modest rate, and detonate when they touch something. The result is a shower of shaped charges covering a roughly circular area at some, presumably suitable, density. Note that this means that, compared to a direct hit on an armored vehicle by a conventional artillery shell, required aiming accuracy is less. There was some sort of claim on the display panel that the shaped charges are effective against various armored targets that the US Army cares about -- I don't recall the exact wording. But it seems likely to me that modern tank armor (e.g., Chobham) can't be pierced by shaped charges of such small diameter. Now, my questions: (1) Is there any truth to the Army assertion of effectiveness for this 155mm anti-armor ammunition? If so, against what targets? (2) My own guess was that this ammunition would be most effective against trucks and other logistical targets like ammo/fuel dumps; any validity to this guess? Don Wells [mod.note: I believe this sort of artillery round is referred to as ICM -- Improved Conventional Munitions. I would also be willing to bet that even those tanks carrying Chobham-style armor do not employ the expensive composite on horizontal (deck) surfaces; these probably are armored with about 30mm of steel only, and would still be vulnerable to small shaped charges. - Bill ] -- Donald C. Wells, Assoc. Scientist | dwells@nrao.edu Nat. Radio Astronomy Observatory | 6654::DWELLS Edgemont Road | +1-804-296-0277 38:02.2N Charlottesville, VA 22903-2475 USA | +1-804-296-0278(Fax) 78:31.1W
jwm@wdl76.wdl.fac.com (Jon W Meyer) (10/25/90)
From: jwm@wdl76.wdl.fac.com (Jon W Meyer) dwells@fits.cx.nrao.edu (Don Wells) writes: >The shell contains small bomblets. My memory is that they were of >order 40-50mm in diameter, perhaps 80-100mm long. They have a cloth >"tail" on them, kind of like a kite tail. The bomblets, as I call >them, are *shaped charges*. The 155mm shell body contains a >considerable number of them, several dozen at least. This is DPICM (Dual Purpose Improved Conventioanl Munition). >There was some sort of claim on the display panel that the shaped >charges are effective against various armored targets that the US Army >cares about -- I don't recall the exact wording. But it seems likely >to me that modern tank armor (e.g., Chobham) can't be pierced by >shaped charges of such small diameter. Now, my questions: >(1) Is there any truth to the Army assertion of effectiveness for this >155mm anti-armor ammunition? If so, against what targets? I've seen video tapes of tests of DPICM against armor, and the results were quite impressive. Can we kill the the latest or greatest tanks on the market with DPICM? The army says yes, but I don't know for sure. Can we kill the older tanks that (I believe) make up the bulk of Iraq's armor. No problem. >(2) My own guess was that this ammunition would be most effective >against trucks and other logistical targets like ammo/fuel dumps; any >validity to this guess? Trucks on the move might call for DPICM (the shotgun effect would increase the number of kills per round). Ammo/fuel dumps are better targets for "shake n' bake" missions - H.E. and W.P. (White Phosphorous). >Don Wells Jon ____________________________________________________________________________ Jon W. Meyer | "I'd travel 10,000 miles to smoke a camel" FA, CA ARNG | Caption from an (unofficial) desert shield tee-shirt. | | "If, when the battle's over, your infantry doesn't love you | you are a poor artillery man."
hsu@eng.umd.edu (Dave "bd" Hsu) (10/25/90)
From: hsu@eng.umd.edu (Dave "bd" Hsu) In article <1990Oct22.040305.18740@cbnews.att.com> dwells@fits.cx.nrao.edu (Don Wells) writes: >The shell contains small bomblets. My memory is that they were of >order 40-50mm in diameter, perhaps 80-100mm long. They have a cloth >"tail" on them, kind of like a kite tail. The bomblets, as I call >them, are *shaped charges*. The 155mm shell body contains a >considerable number of them, several dozen at least. This reminds me of an article in Scientific American about 9 years ago describing two column-killer projects, "Assault Breaker" and "MLRS". The former was described as a research testbed for dispensing multiple antitank and antipersonnel submunitions; the latter was described as a rocket, launchable from a 155's tube, which would dispense several antitank submunitions in hopes of disabling the front of an armor column. MLRS was to go into service in 1982 or 1983. What ever became of these programs? -dave -- Dave Hsu Systems Research Center, Building 115 (301) 405 6594 hsu@eng.umd.edu The Maryversity of Uniland, College Park, MD 20742-3311 "Wris woo chin dow fip ak," said one teaching assistant [who could not be reached for comment]. - UW-Madison Badger Herald
ab3o+@andrew.cmu.edu (Allan Bourdius) (10/29/90)
From: Allan Bourdius <ab3o+@andrew.cmu.edu> The MLRS (Multiple Launch Rocket System) is an independent system, using a tracked launcher based on the M2/M3 chassis that carries 12 ready rounds. The rockets are unguided in flight and can be fitted with conventional, cluster, smoke, incendiary, or chemical warheads. Allan