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From: jonke@BRL.MIL (Patrick Jonke)
Newsgroups: sci.military
Subject: Reactive Armor
Message-ID: <1991Feb4.062819.19704@cbnews.att.com>
Date: 4 Feb 91 06:28:19 GMT
Sender: military@cbnews.att.com (William B. Thacker)
Organization: AT&T Bell Laboratories
Lines: 37
Approved: military@att.att.com



From:     Patrick Jonke <jonke@BRL.MIL>
(Note: This is my first submission to sci.military so please forgive me
if I do something incorrectly!



> From:     "Larry W. Jewell" <JEWELLLW@VM.CC.PURDUE.EDU>

> Footage from Sandy Arabia shown M-60's with large flat plates attached
> to the turret.  Is this reactive armour?

Yes.

> Any idea how it works and how much confidence the tankers have in it? 

First generation reactive armor consists of two thin metal plates sandwiched
around a slab of explosive.  When a shaped-charge jet penetrates the outer
plate, it detonates the explosive filler which then propels the outer metal
plate away from the vehicle and the inner metal plate towards the vehicle.
Because the plates are (hopefully) at an angle to the jet, new metal is
continuously placed in the path of the jet.  Here is a crude diagram to show
how this works:

						    		 __
                                                   /            |\
                                /                 +               \
              /                +                 +                 \
JET t=0 ----->      JET t+1 --+-->     JET t+2 -+--->           Direction of
            /                /                 /                 plate motion
           /                /
          /

The greater the angle of incidence, the more metal that is placed in the path
of the jet.  If the jet strikes perpendicular to the plate, the reactive
armor provides negligible additional resistance.