AP rounds fired by arty

[loktarr]

Made some test (I love doing tests with SPMBT...):
the poor English were the target, firing unit was US paladin.
Target were grouped by 8 (vehicles or team), with two paladin firing at each target group. Target were immobile...
Here are the losses ratio[%], with (20)= roof anti-heat armor:
Challenger 2 (20) [50%]
Warrior II (5) [90%]
Spartan (1) [90%]
LandRover (0) [35%]
Medium Truck (0) [35%]
Infantery (-) [15%]

(I got these figures after 5 tests)
I may have the reason why there is a lowest ratio of destroyed unarmored vehicle: the ammo are AP and it seem that unarmored vehicle are easily destroyed by HE but not by
AP...
A test with MRL confirms it: for MRL cluster ammo are HE ammo and it's able to destroy easily unarmored vehicles...
Does anybody know more about how SP deals with unarmored vehicles hit by AP rounds?

[PlasmaKrab]

I didn't do any test on that, but I'm beginning to wonder if it isn't smothing related to the way soft vehicles are dealt damage (any damage).

Try firing against trucks or such with a tank or any heavy direct-fire weapon, and you'll have chances of seeing the truck losing crew members, but still technically running between two shots.

Just my 2c, I don't know if there is any relation with what you saw. If there is, you may want to check non-lethal damage done to the trucks, maybe several of them are technically "ready" but have suffered several damage points.

P.S. just another idea popping up: how about unit size? Tanks tend to have a high size ratio, and seeing how cluster rounds work, I'd find totally logical that 'smaller' units get less hits.

[Mobhack]

Soft vehicles take crew casualties. If they are not located by the firer at the time that will not be reported to him in your testing. They will tend to debuss any passengers when hit, and the supression levels will go up as well - they may be in retreat status. Again - your test may not show this if the potential targets are over a hill say. Only total kills will be shown in such a test (to test arty it is best to have a spotter close to and overlooking the impact zone)

Cheers
Andy

[loktarr]

In fact, I made my test with human control for both players, so I was able to know everything about casulties...
However, your answer gives a very clear explanation: theses ammo are not very effective against crew, and then it's slower to kill soft vehicles: if one wants to kill soft vehicles, I suppose one has to use the HE rounds.

[whdonnelly]

The only thing I can think of is a story an Abrams gunner told me. At long range a dark smudge on the horizon can be a tank, a truck, or a camel, so they have engaged some questionable targets more than once. Once they were engaging a target that turned out to be a land rover. After 4 hits which tore away the canvas, the windshield, and various fenders, the land rover still drove. Maybe the shock of a hit isn't absorbed by the whole vehicle, unlike an AFV. Following this reasoning, softer targets would have less critical hits than an AFV.
Would this apply to the arty rounds? Not my area of expertise, but it seems logical.
Will

[pdoktar]

Yeah, 5kg sabot dart traveling at 1500 m/s isn�t going to expend any enrgy going through a canvas or a windshield or some regular car bonnet. The HEAT ammo may not even detonate going through thin objects, and will appear to detonate, but only behind the vehicle hitting ground. But a HEAT or a SABOT through the engine, that�s another story.

Hail for the real comeback of 120mm HE rounds!

[Marcello]

Yah, 5kg sabot dart traveling at 1500 m/s isn�t going to expend any enrgy going through a canvas or a windshield or some regular car bonnet.

Pretty much.Most of the mechanisms that an APFSDS uses to inflict damage on a tank, from spalling to thermal effects, don't work well against thin skinned vehicles (bar hits on the engine and similar of course).Artillery cluster munitions should be a different matter however, as these use explosive bomblets.
Against tank fired HEAT rounds it should boil down to how much the fuze is sensitive and if it impacts something hard enough to trigger it.If that happens then you have a very dead Land Rover.

[PlasmaKrab]

Regarding the sensitivity of HEAT fuzes, I'm not sure that the material hit is very relevant at the impact velocities considered.
Think about the "necklace" of the Merkava Mk3/4: there are simple weighted chains dangling from the turret basket, and they are supposed to (and I guess reliably tested to do so) detonate RPG rounds at a standoff from the turret.

I'm out on a limb with my physics here, but I'd say that the inertia of the chains (in this example) prevents them from being significantly displaced before the fuze fires.
The same thing can probably be said of any unarmored vehicle bonnet, given the material is hard enough.
Admittedly, a canvas top has a chance of folding around the fuze probe, or ripping open, letting the fuze tip through, and stop only the thin and conductive warhead cover,making the round a dud. As far as I know that was how RPG fences worked back in Vietnam.

Just my 2c, don't ask me to back that up with calculation!