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From: pierson@cimnet.dec.com
Newsgroups: sci.military
Subject: Re: Mortars & Tanks (and tracers)
Message-ID: <8033@cbnews.ATT.COM>
Date: 7 Jul 89 04:38:23 GMT
Sender: military@cbnews.ATT.COM
Organization: Digital Equipment Corporation
Lines: 44
Approved: military@att.att.com



From: pierson@cimnet.dec.com

In article <7986@cbnews.ATT.COM>, chris@ziebmef.uucp (Chris Graham) writes...
>  How effective are mortar rounds against tanks?  And what kinds of tanks/APCs
>would mortars be effective against.  I believe that tank armor is a lot lighter
>at the top than around the sides.
	Not very, I think.  Assuming conventional 60mm/80mm mortars, two reasons
	come to mind:

	1) The fire control problem.  If the tank/afv is in motion, it will
	be nearly impossible to hit with a high angle/long time of flight
	projectile.

	2) I don't know of any "armor piercing" mortar projectiles.
	Even "thin" armor (does 2" sound right, for top of hull?) will require
	an AP of some sort.  (OK, they could be built...).

	That said, hits on the engine compartment/external stores might be
	effective, however the fire control problem is still large.

Historical interlude: ca 1890/1900 "seacoast mortars", typically around 12",
were popular for coast defense.  The objective was to shells drop onto the
lightly (some times un) armored deck of battleships, etc.  The fire control
problems  were complex, and the targets less able to change direction rapidly
than modern AFV's.
===================
Someone inquired about tracers.  Small hollow in base of projectile (bullet
or shell, as appropriate.  First goes some illuminating mix, to make the 
visible trail.  This is lit off by a "dark fire" which delays ignition so the
round is clear of the gun, burns where its needed, and (for ground use)
avoids making the weapon position obvious.  This is topped off with "primer"
or "first fire", which is lit by the propellant gasses.  (The layers light
off in the reverse order from that that I have named.)  Mix of tracer was,
"variable" sometimes being loaded to suit the mission, sometimes fixed.
I believe one typical mix was one in five rounds were tracer.

thanks
dave pierson			|The facts, as accurately as I can manage.
Digital Equipment Corp		|The opinions, my own.
600 Nickerson Rd
Marlboro, Mass
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