jkmedcal%uokmax@uokmax.uucp (Jeff Medcalf) (05/06/89)
From: Jeff Medcalf <jkmedcal%uokmax@uokmax.uucp> It might not be practical to actually shoot something at an incoming torpedo, but whether or not it is, the Navy has some torpedo defenses. The major one is called Nixie. It is a towed decoy which imitates the sounds of the ship, only louder, in order to attract acoustic torpedos. I have heard of a system called Prarie or some such, which essentially consists of two loops around the hull underwater. These rings have holes in the back side of them through which air is bled, the bubbles apparently masking the ships engine noises quite well and thus reducing their acoustic signatures. If anyone has any more info on this, I would like to see it. Is it Navy doctrine that the 20mm and 30mm guns fitted in singles to the bridge wings of some ships would attempt to take out torpedos? -- jkmedcal@uokmax.UUCP | "Open the pod bay doors, Hal." jkmedcal@uokmax.ecn.uoknor.edu | "I'm afraid I can't do that, Dave." Jeff Medcalf | -2001 [mod.note: In the realm of antitorpedo defenses, would it be feasible to link a Phalanx system to sonar, rather than radar, for firing at shallow-running torps ? It should be effective to a reasonable depth, and a single hit should disable a torpedo. I don't know much about sonar capability, though. - Bill ]
royf@roxanne.StPaul.GOV (Roy Forsstrom) (05/10/89)
From: royf@roxanne.StPaul.GOV (Roy Forsstrom) In article <6318@cbnews.ATT.COM> jkmedcal%uokmax@uokmax.uucp (Jeff Medcalf) writes: > > >From: Jeff Medcalf <jkmedcal%uokmax@uokmax.uucp> >It might not be practical to actually shoot something at an incoming torpedo, >but whether or not it is, the Navy has some torpedo defenses. > >Is it Navy doctrine that the 20mm and 30mm guns fitted in singles to the bridge >wings of some ships would attempt to take out torpedos? They must be there to shoot at something, but you need someone who can aim! Story follows... The California, CGN-36, had 50 caliber guns mounted on the bridge just before we sailed back to our second visit to Gonzo Station, just outside the Straits of Hormuzk, in '81. We were supposed to go through the Suez, and had made it to Italy, when we were denied permission and had to sail all the way around Africa. The America and escorts were permitted through the canal. We were told the 50 cal guns were to protect the ship against ground fire from the shore while transiting the canal. However, after we arrived on station, we were told the guns were to shoot at incoming missles, ala Phalanx close-in-support. The America already had her cannons by then. One morning the guns were put to the test. We rescued several crewman from a burning Greek freighter who were in a liferaft about 40 south of the fire. Instead of pulling up the raft (you don't leave empty life rafts floating around) the OOD decided to sink it to get some target practice for his boson's with the 50 cals. After nearly 1 hour of shooting at the raft at ranges from 100 yrds to 1/4 mile, the raft was still afloat. It suffered only a couple of hits. A boat was put over the side to retrieve the raft. The combination of poor training, motion of the ship and motion of the raft resulted in a rather disappointing demonstration. A missile or torpedo with only a 1 square foot presentation makes a terribly difficult target for a manually aimed gun. =============================================================================== Roy Forsstrom uucp: pwcs!royf Public Works Computer Services internet: royf@pwcs.StPaul.GOV 25 W. 4th Street rboc: 612-298-5569 St. Paul, MN 56102 ===============================================================================
military@att.att.com (Bill Thacker) (05/12/89)
From: military@att.att.com (Bill Thacker) >They must be there to shoot at something, but you need someone who can aim! >... >After nearly 1 hour of shooting at the raft at ranges from 100 yrds to 1/4 >mile, the raft was still afloat. It suffered only a couple of hits... >The combination of poor training, motion of the ship and motion of the >raft resulted in a rather disappointing demonstration... Tsk tsk, one would hope that the "gunnery revolution" of the beginning of the century hadn't been forgotten *quite* so completely! :-) For those who don't know what I'm referring to, the standard of naval gunnery circa 1900 was abysmal. In particular, standard practice was to point the gun more or less correctly and then wait for the ship to roll into the right position to line up the sights. This sounds okay in theory but works very poorly in practice. The "gunnery revolution" was started by a Royal Navy captain (whose name I have forgotten, dammit) who happened to observe a natural "gunlaying genius" practicing in weather rough enough that everyone else had long since given up. The trick is to correct for wave motion instead of waiting for it, so that the gun is stable with respect to the horizon. This requires a fair amount of exertion with a heavy gun (we aren't talking about 50-cal here, but about hefty naval guns) and considerable practice, but the results are spectacular. The accuracy of naval gunnery improved by (literally) several orders of magnitude within a few years. (Well, I should admit that compensation techniques weren't the only factor involved. Another was a massive shift in emphasis away from the polish of the paint and towards the accuracy of the gunnery.) Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu