Re: [SGII] Fire of AT Missiles at disperesed tagets

Ryan Gill wrote:

>>Other than directly ahead of the ATGM, even a small mortar round has a

>>considerably greater lethal effect.
>
>I had always thought the HE was focused towards the shaped charge, but 
>that there was a secondary annular blast that was still not to be
shrugged at.

The secondary blast is nasty enough to cause concern for the gunner at
very 
short firing ranges - ie., if you fire enough of them at short ranges
(eg. 
in training) you run a non-negligible risk of getting hit by shrapnel
from 
your own weapon at some point in your life.

It isn't enough - that is to say, the "lethal radius" is too small - to
be 
consistently useful against dispersed targets (and you don't have enough

missiles to fire them at such targets hoping that it *might* work).
Pretty 
much any SGII squad not inside a vehicle or building, even if all the 
figures are in base-to-base contact, is effectively a dispersed target 
since each figure's base is some 5 - 10 meters across in the SGII ground
scale.

Because the users want to be able to use our products at ever shorter 
ranges, and also because any energy that isn't going towards the primary

target is wasted in an anti-armour weapon, there's a *lot* of work going
on 
to minimize the amount of blast and shrapnel that goes anywhere else
than 
into the primary target.

>To modern Shaped charges have any kind of restricting material around
the 
>HE component to optimize the blast towards the cone?

Yes. In HEAT rounds this casing is usually designed to form as few, as 
large and as slow fragments as possible in order to maximize the amount
of 
energy that goes into the armoured target. In HEDP rounds it is
frangible, 
but HEDP rounds give up a quite significant proportion of their armour 
penetration in order to play second-rate HEF - generally speaking HEDP 
warheads are effective against lightly armoured targets like light APCs
or 
aircraft, but don't try to use them against tanks.

>Granted there generally isn't any fragmentation component on them but
even 
>something like IPDSM is nasty to be near as they have an area frag
effect 
>and a shaped charge piercing effect.

I suspect that you mean "DPICM" rather than "IPDSM" - not least because
I 
couldn't find the latter acronym in any of the databases I searched :-/
The 
DPICM is a HEDP warhead with a lethal radius of 5-10 meters against 
unarmoured infantry (depending on who you ask); but unlike an ATGM the 
DPICM has neither a rocket engine nor a fin assembly (or other steering 
equipment, eg. small attitude rockets) which blocks much of the outgoing

shrapnel. The DPICM also falls roughly vertically (ie., with the 
shaped-charge cone pointing straight down), so it doesn't send a third
or 
so of its "secondary" shrapnel straight down into the ground the way 
horisontally-flying ATGMs tend to do. (Dive-attack missiles like the 
Javelin attack more or less vertically just like the DPICM, of course.)

All in all I'd rate the DPICM as considerably nastier to anyone not 
directly in front of its shaped-charge than most ATGMs are, even though
the 
DPICM is far smaller.

>Could a man portable ATGM with enough diameter to it's shaped charge
have 
>a secondary Frag effect in it's blast radius?

You could build it that way, but then it loses a lot of its anti-armour 
capability.

>Gosh, thinking about the general cone shaped effect of old WWII style 
>artillery (HE rounds) is there a similar effect with lower velocity
ATGMs?

If you're thinking of the "butterfly-shaped" shrapnel distribution
patterns 
typical for WW2 HE rounds, there is a similar effect with ATGMs but with
a 
quite different shape to the pattern.

>So where those TOW missiles I saw being fired down streets in Fallujah 
>being fired at individuals or masses? ;-)

They were fired at buildings, not at people out in the open.

>The footage I see from Fallujah and its environs
>seems to be about destroying the ability of the
>enemy to fight. In fact theres an E5 Marine in
>Tikrit that's wanting something more effective
>than a 40mm grenade launcher when dealing with
>walls and such where Haji's are shooting from
>behind.

If they're behind walls, they're not out in the open. A wall is a hard 
point target.

>Overall, you're putting the round on a point, not on a trooper (more or

>less). In that case, I'd expect the GMS/P guidance system to have a
second 
>mode for engaging a given point of ground as opposed to a heat 
>source/contrasting object.

Unless you want to guide the GMS/P all the way to the target (like you
do 
with Saggers or TOWs - and you don't want that, since it makes you a
nice 
target for the return fire; that's why fire-and-forget missiles are so
hot 
nowadays), there needs to be something for the GMS/P to lock on to...
ie., 
a contrasting object of some sort. Whether the contrast is in shape,
heat, 
reflected light or even magnetic properties doesn't matter that much
(all 
of these contrasts are used in target seekers today), but there has to
be 
*some* sort of contrast.

Later,

Oerjan
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."
-Hen3ry