[sci.military] Mortars & Tanks

chris@ziebmef.uucp (Chris Graham) (07/06/89)

From: chris@ziebmef.uucp (Chris Graham)
  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.

pierson@cimnet.dec.com (07/07/89)

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
01742

gahooten@ames.arc.nasa.gov (Greg A. Hooten) (07/08/89)

From: gahooten@ames.arc.nasa.gov (Greg A. Hooten)

There is some work being done on what are called brilliant
mortor rounds for anti tank work.  They are essentially a
shell with a target distinguishing system in the nose, and
control veins along the sides.  The Mortor is fired at an on
coming column.  The round gets to altitude and starts
attempting to track a tank.  If it finds one, then it homes on
the radar reflection (supposedly ignoring ground clutter) and
hits the top of the tank.  Apparently, successful tests have
been completed, but the rounds are expensive. 

GAH!

allen%codon1.Berkeley.EDU@ucbvax.Berkeley.EDU (Edward Allen;345 Mulford;x2-9025) (07/11/89)

From: allen%codon1.Berkeley.EDU@ucbvax.Berkeley.EDU (Edward Allen;345 Mulford;x2-9025)



I think mortars are probably more effective vs armor than the posting by
Dave Pierson about armor penetrating ability would suggest.  He
concentrates on what happens to a tank if a mortar round lands diectly on
the top armor.  Whether or not this will penetrate, having it explode
against the outside of the relatively thin top armor may do damage on the
inside by spalling and concussion, particularly in the case of the larger
mortars, 120mm +. You'll get the kind of effect that HESH shells are
optimized for, although to a lesser degree.  But that is probably not the
primary damage that mortar shelling is likely to do to tanks.  You're
going to see some tracks knocked off, and casualties to exposed crews.  I
remember reading that most casualties to tankers in WWII occured when they
weren't protected by armor, with crewmembers caught by shelling 
in the majority of the time when they are eating, sleeping, doing
maintainance, just waiting around, etc.
Then there are hits on the gratings over the engine compartment with the
possibility of an engine kill, and on vision
blocks and periscopes, antennas, external MGs, and things like that which
will cause the tank problems without knocking it out.  There's good reason
to target mortars at tanks if you don't have more vulnerable targets to
hit or if the mortars are the heaviest thing available.  It will at least
keep the tankers uncomfortable.

Ed Allen (allen@enzyme.berkeley.edu)

military@cbnews.UUCP (08/15/89)

From: ssc-vax!shuksan!major@beaver.cs.washington.edu (Mike Schmitt)

In article <8129@cbnews.ATT.COM>, allen%codon1.Berkeley.EDU@ucbvax.Berkeley.EDU (Edward Allen;345 Mulford;x2-9025) writes:
> 
> From: allen%codon1.Berkeley.EDU@ucbvax.Berkeley.EDU (Edward Allen;345 Mulford;x2-9025)
> 
  (much about engaging tanks with mortars:)


  Ed, technically I agree with you on the use of mortars vs tanks.  At
  least it will keep the crews buttoned up (limit visibility) and destroy
  their sleeping bags and MRE cases (C-rations) in the bustle rack - knock
  off antennas (antenni?) and give the crews headaches.  And if that's all
  you've got - then fire away (throw in a few rounds of smoke and white
  phosphorous, too).  

[mod.note: "Antennas" or "antennae" are both correct.  - Bill ]

  Tactically, however, I would think that the tanks are accompanied by
  infantry (they should be) and the mortars should engage them (infantry,
  AFVs, thin-skin vehicles) first.  And, if the mortars are part of a
  'combined arms team' there should be some Direct Support Artillery
  around (155mm) that can engage the tanks with Dual-Purpose ICM (improved
  conventional munition), that are tank-defeating rounds.  Then, of course,
  there's always the TOW-Cobras and A-10s loitering around waiting for 
  targets. 

  Personally, I wouldn't engage tanks with mortars - it might make them
  very angry at me.  But, if all I had to engage tanks with were mortars,
  I shouldn't be there in the first place.    :-)  :-)


  mms
 
  

davecb@nexus.yorku.ca (David Collier-Brown) (09/06/89)

From: davecb@nexus.yorku.ca (David Collier-Brown)
Mike Schmitt probably writes:
|  Personally, I wouldn't engage tanks with mortars - it might make them
|  very angry at me.  But, if all I had to engage tanks with were mortars,
|  I shouldn't be there in the first place.    :-)  :-)

   Once upon a time, I was a lowly lance-corporal in the canajan farces,
being taught about the 60mm mortar.  The instructor commented that they
were also used as a flat-trajectory weapon mounted in the turret of a
then-current british scout car....

   When we got to the range to actually fire the little creature at a very
dead ex-tank, it became obvious that at the short ranges we were firing
at (150-250m) it was "too easy" to hit the tank using vertical trajectory.
So we asked the instructor if we could try firing flat trajectory.  After
being **real** sure we had the spade base well dug in, he handed us three
bombs with all the boosters still attached, and told us to try and
hit the tracks.
   After bouncing several rounds across the ground (!) and making dust
clouds in front of the tank, we  got the third bomb to fly all the way
to the tracks... and watched the track split.  
   We had a very productive afternoon of blowing the tracks up: about
two out of three people could break a link within three bombs.  Of course,
we were shooting at the **side** of the tank, not the front of the track.

   Tactically, this amounted to disabling a tank that was either right on
your lines or just inside them: a serious annoyance to the people that
the tank was parked amoung.  Not to mention that they probably wouldn't 
like their own troops firing mortars three feet over their heads!

--dave

ps: the 60 mm is fired by pushing a little lever on the side, not merely
    dropping a bomb down the barrel.  Presumably the scout-car version
    had some sort of breech-loading scheme as well.
-- 
David Collier-Brown,  | davecb@yunexus, ...!yunexus!davecb or
72 Abitibi Ave.,      | {toronto area...}lethe!dave 
Willowdale, Ontario,  | Joyce C-B:
CANADA. 223-8968      |    He's so smart he's dumb.