Path: spln!rex!dex!extra.newsguy.com!lotsanews.com!nntp1.phx1.gblx.net!nntp.gblx.net!nntp.gblx.net!news.maxwell.syr.edu!news-out.visi.com!hermes.visi.com!gemini.tycho.net.POSTED!not-for-mail Approved: sci-military-moderated@retro.com Return-Path: news@google.com Delivery-Date: Tue Oct 30 16:45:10 2001 Delivery-Date: Tue, 30 Oct 2001 16:45:10 -0800 for <sci-military-moderated@retro.com>; Tue, 30 Oct 2001 16:45:09 -0800 (PST) for <sci-military-moderated@moderators.isc.org>; Tue, 30 Oct 2001 16:28:57 -0800 (PST) for <sci-military-moderated@moderators.isc.org>; Tue, 30 Oct 2001 16:28:57 -0800 for <sci-military-moderated@moderators.isc.org>; Tue, 30 Oct 2001 16:28:56 -0800 for sci-military-moderated@moderators.isc.org; Tue, 30 Oct 2001 16:28:56 -0800 To: sci-military-moderated@moderators.isc.org From: psl@interchange.ubc.ca (Paul Lakowski) Newsgroups: sci.military.moderated Subject: Re: WWII Armor types Date: 30 Oct 2001 16:28:56 -0800 Organization: http://groups.google.com/ Message-ID: <de5bf54f.0110301628.3de4685d@posting.google.com> References: <5dcb47db.0110260556.1019019@posting.google.com> <9rej52$7c8$1@thorium.cix.co.uk> <5dcb47db.0110271754.5bd4c309@posting.google.com> <de5bf54f.0110281446.2c24b883@posting.google.com> <5dcb47db.0110300524.50487c31@posting.google.com> X-NNTP-Posting-Host: 207.23.94.25 Content-type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Complaints-To: groups-abuse@google.com X-NNTP-Posting-Date: 31 Oct 2001 00:28:56 GMT Content-Length: 2369 Lines: 42 NNTP-Posting-Host: f0db9685.newsreader.tycho.net X-Trace: 1004549429 gemini.tycho.net 436 205.179.181.194 X-Complaints-To: abuse@tycho.net Xref: spln sci.military.moderated:39962 cray74@hotmail.com (Mike Miller) wrote in message news:<5dcb47db.0110300524.50487c31@posting.google.com>... > psl@interchange.ubc.ca (Paul Lakowski) wrote in message news:<de5bf54f.0110281446.2c24b883@posting.google.com>... > > > Looking at the anti heat theory the previously mentioned standoff > > penetration figures for steel liner shaped charges [ WW-II HEAT] > > suggest that since the PZfausts warhead standoff was only 0.4 to 0.6 > > cone diameters stand off.Which means that any amount of spaced plate > > should have increased the penetration substitally . These 'Schnerzen' > > plates offered standoff distance of about 66cm {Pz tracks #4} which is > > 4.4 cone diameters for a Pzfaust. At these standoffs the penetration > > should up 35-50% and not down at all. > > > The standoff on a bazzooka is ~ 2 cone diameters [J of Applied Phys > > 1948 Vol 19, pp575]and the penetration should be ~ 2 cone diameters > > penetration and any increase should reduce this penetration to 1.3 > > cone diameters @ 9:1 standoff ~ 51cm which is still a penetration of > > > 3.5 inches RHA. Still more than enough to penetrate the side armor of > > just about any tank in WW-II. > > Are you simply looking at standoff values for gauging the > effectiveness of HEAT when triggered a spaced distance from the > hull, or are you factoring in the effect on jet coherency > after penetrating the spaced skirts? > > It would seem that after penetrating a spaced armor skirt, the > jet from a HEAT munition would no longer be as coherent as > one that simply passed through additional free space. I know > penetrating the skirt would be trivial for the HEAT, but that > does not mean the HEAT's jet stays "pencil-thin" after penetrating > the skirt. High velocity impacts make matter do funny things. > > Mike Miller, Materials Engineer Yes at this point the effect is just standoff, but the effect of the plate is less than you suggest. Going on HD theory the plate will obstruct until a sufficently large enough hole is driven though, at which point the follow on jet material will continue on without interuption. The effect of straight steel plate is substantial 3-4 times the plate thickness from the tests I've seen.With layered plates [ steel aluminum] the disruption can be 7-10 times the plate thickness. But once that plate is cleared the jet will continue on.