Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!uxc!iuvax!rutgers!att!cbnews!anderer@vax1.acs.udel.edu From: anderer@vax1.acs.udel.edu (David G Anderer) Newsgroups: sci.military Subject: Re: USS Iowa explosion Message-ID: <5937@cbnews.ATT.COM> Date: 26 Apr 89 04:10:15 GMT References: <5789@cbnews.ATT.COM> <5838@cbnews.ATT.COM> <5890@cbnews.ATT.COM> Sender: military@cbnews.ATT.COM Organization: University of Delaware Lines: 41 Approved: military@att.att.com From: David G Anderer In article <5890@cbnews.ATT.COM> dave@viper.Lynx.MN.Org (David Messer) writes: >This is fine accept that the WWII vintage powder was found to not >burn consistently. I'm sure that the radar told them just how far >each round was going to miss by, but it doesn't help much once the >rounds are out of the tube. > I came across some more information on this over the weekend. Source is "Iowa Class Battleships, Their Design, Weapons and Equipment" (Robert Sumrall, 1988): Smokeless powder is basically unstable because it contains nitrocellulose and three volatiles, ether, alcohol, and water (water is considered a volatile because it promotes deterioration of the propellant). Even though it is stored under special conditions it deteriorates in time and some of the volatiles are lost. This is especially true of the grains stored near the top of the storage tanks or stacked near the outside surfaces of the bags. The deterioration affects the muzzle velocity of the projectile producing erratic range and dispersion of the shot. For example, when the D839 propellant was first produced in the 1940s, the original acceptance standards were +/- 10 ft/sec in initial velocity. The actual variation was less than +/- 5 ft/sec with the 2,700 pound projectile. During the Korean War is was about +/- 14 ft/sec with the 1,900 pound projectile. The New Jersey's Vietnam deployment recorded about +/- 23 ft/sec with the 1,900 pound shell and on station off Lebanon during 1984 it was about +/- 32 ft/sec using the 1,900 pound shell. ----- However, remixing the powder does help. Later in the book he cites a 1987 firing test by the Iowa: at 34,000 yards a pattern size of 219 yards. 14 of 15 rounds landed within 250 yds of the target; 8 of 15 landed within 150 yds. -- Dave Anderer Academic Computing and Instructional Technology University of Delaware