Cluster munitions question.

[Bahnzo]

Still learning the game. In the NTC campaign I was given some arty with cluster bombs. I placed it in an area I scouted in which the enemy had a lot of command vehicles parked. 

What I'm curious about is if I should've used a small radius? What I did was simply place a large circle over the area. But I noticed that seemed to space out the cluster bombs and didn't do as much damage as I had hoped. I wonder if I had used a smaller area if it would've concentrated the bombs and made them more lethal? 

[The_Capt]

16 hours ago, Bahnzo said:

Still learning the game. In the NTC campaign I was given some arty with cluster bombs. I placed it in an area I scouted in which the enemy had a lot of command vehicles parked. 

What I'm curious about is if I should've used a small radius? What I did was simply place a large circle over the area. But I noticed that seemed to space out the cluster bombs and didn't do as much damage as I had hoped. I wonder if I had used a smaller area if it would've concentrated the bombs and made them more lethal? 

Short answer is “yes”.  Cluster munitions need high density to get the most out of them.  So targeting needs to be at choke points or enemy troop concentrations.  And drops should be multiple rounds in as tight an area as you can get.  I personally find linear shots work better.  Also remember that cluster munitions do more damage than you may see, especially for tanks.  They are really designed to take out APCs and strip infantry away from armour, but for tanks they will cause systems damage (guns, sights, engines).  The best target is dismounted infantry, especially for US DPICM.  If you can catch a Soviet company dismounted in the open a single cluster salvo can wipe it out.

[Bahnzo]

I like the idea to use linear, I can see how that would work well. I guess what I don't understand is if the dispersal pattern of the bomblets changes with the size of the area, or if that's a set spacing and using a smaller area simply puts more shells in that area? I guess I need to learn how to set a test range so I can run experiments like this. 

[The_Capt]

1 minute ago, Bahnzo said:

I like the idea to use linear, I can see how that would work well. I guess what I don't understand is if the dispersal pattern of the bomblets changes with the size of the area, or if that's a set spacing and using a smaller area simply puts more shells in that area? I guess I need to learn how to set a test range so I can run experiments like this. 

It changes with area size and number of rounds fired.  So if you  draw a big target circle with a few rounds, the strikes get pretty tepid - even with traditional HE. It is all about balancing to the target.  Running some tests is a really good way to learn the game.

[A Canadian Cat]

35 minutes ago, Bahnzo said:

I guess what I don't understand is if the dispersal pattern of the bomblets changes with the size of the area, or if that's a set spacing and using a smaller area simply puts more shells in that area

It's the second thing. Each individual round will have a similar dispersal pattern for its bomblets. If your target area is wide then the rounds will be spaced wide apart and there can be areas that never get effected by a single bomblet. Make the area tighter and you have overlap from the dispersal from multiple rounds and no area goes without seeing an effect from multiple bomblets.

[MikeyD]

I searched old 2020 Beta board discussions of anti-tank cluster munitions and found an extract of an official paper on the topic (sorry, I've forgotten what the source was). The paper asserted that DPCIM needs something like ten (randomly placed) hits on a tank to guarantee a kill. Its not quite that bad in-game but successful use of cluster munitions seems to rely heavy on luck.

Quote

Based on the placing, size and distribution of such components, it may be stated that an armoured vehicle needs of the order of 10 hits with a DPICM in order to inflict a kill. For vehicles not containing large amounts of ammunition, the number will be even higher. Against modern tanks and modern howitzers, with adequate roof protection, the number may be still higher. 36 FFI-rapport/2007/02345 This view can be supported by a report based on the experience of the Russian army in Chechnya in 1994[11]. This report presents the vulnerability of armoured vehicles. However, it can also be seen as an indication on how invulnerable such vehicles are, as three to six shots by shoulder fired RPGs were needed to inflict a lethal damage to the vehicles. The warheads of RPGs are at least three times better in terms of penetration capacity than a typical DPICM bomblet. In order to achieve 10 hits, an armoured vehicle has to be inside the footprint of an M483A1 155 mm DPICM11 around 200 times, which clearly shows the futility of defeating large armour formation with this kind of munition unless when there are a high number of targets within the footprint area. Other kinds of DPICM, containing a smaller number of bomblets are even less effective.

 

[The_Capt]

5 hours ago, MikeyD said:

I searched old 2020 Beta board discussions of anti-tank cluster munitions and found an extract of an official paper on the topic (sorry, I've forgotten what the source was). The paper asserted that DPCIM needs something like ten (randomly placed) hits on a tank to guarantee a kill. Its not quite that bad in-game but successful use of cluster munitions seems to rely heavy on luck.

 

I never bought that paper to be honest.  I dug up artillery studies that determined DPICM was 2-3 times more effective than HE on armour for equal salvos.  Further, what constitutes a “kill”? A single DPICM round can take out a gun (gun kill), or damage the engine (mobility kill), or sensors/sights.  In game, test showed pretty realistic behaviours.  The main victims of ICM are APCs/IFVs and dismounted infantry.  This makes sense as the ammo is designed to strip infantry support away from armour leaving them vulnerable to ATGMs.  DPICM will damage armour, significantly in some cases but was never a magic wand, except in the heaviest densities.

For a “lucky strike” munition, western doctrine had 15-20% of total artillery ammunition inventories as DPICM, and likely would have taken more.

Edited June 20 by The_Capt

[Anthony P.]

Considering that an M483 shell contains 88 submunitions, that sounds very high (200 x 88 = 17 600 submunitions). Granted, that assumes that the tank would have to be hit 10 times... but still, one single hit per every 1 760 submunitions?

And as per above, I guess the kill definition may play a role here. "Destroyed" in CM can range from everything from "it brewed up and tossed the turret way into a whole other AO" to "not one actual component was destroyed, but the crew was spooked enough by it to refuse mounting up again".

Mainly though I would take issue with the methodology used. It states that on average three to six RPG hits were required to destroy a tank in Chechnya, and thus draws the conclusion that since DPICM submunitions have only a third the penetration capacity of an RPG warhead, 10 DPICM hits would be required to kill a tank. There are a lot of potential variables at play here which do not seem to be covered. How many of those RPG hits struck thicker frontal armour, ERA or unimportant parts like wheels which DPICM submunitions are much less likely to hit due to hitting from on top? How many of the RPGs scored poor hits because the operator was suppressed or stressed due to being involved in a firefight (factors which DPICM submunitions won't be affected by)?

[The_Capt]

On 6/20/2024 at 10:28 AM, Anthony P. said:

Considering that an M483 shell contains 88 submunitions, that sounds very high (200 x 88 = 17 600 submunitions). Granted, that assumes that the tank would have to be hit 10 times... but still, one single hit per every 1 760 submunitions?

And as per above, I guess the kill definition may play a role here. "Destroyed" in CM can range from everything from "it brewed up and tossed the turret way into a whole other AO" to "not one actual component was destroyed, but the crew was spooked enough by it to refuse mounting up again".

Mainly though I would take issue with the methodology used. It states that on average three to six RPG hits were required to destroy a tank in Chechnya, and thus draws the conclusion that since DPICM submunitions have only a third the penetration capacity of an RPG warhead, 10 DPICM hits would be required to kill a tank. There are a lot of potential variables at play here which do not seem to be covered. How many of those RPG hits struck thicker frontal armour, ERA or unimportant parts like wheels which DPICM submunitions are much less likely to hit due to hitting from on top? How many of the RPGs scored poor hits because the operator was suppressed or stressed due to being involved in a firefight (factors which DPICM submunitions won't be affected by)?

Here is where I wish we had actual data from Ukraine.  A lot of those drones are armed with RPG rounds.  I wonder what the Pk rate is for them as they are hitting from all angles?

I feel like we have all had this conversation before:

https://www.globalsecurity.org/military/systems/munitions/m483.htm. M483 can penetrate about 2.5 inches or roughly 60mm

https://thesovietarmourblog.blogspot.com/2017/12/t-72-part-2.html  Back deck of T72 is only about 20mm and I doubt the turret roof is much thicker.  So we know that from a top attack for DPICM they can very likely penetrate.

Now as to damage. Off the bat, were the tests run on empty hulls or fully loaded tanks?  A back deck hit on a tank fully loaded has high probability of lighting off fuel and starting a fire.  A top turret strike can kill crew but also knock out sights and controls.  The bottom line is that tank armor is made for direct fire (kinetic and explosive) threats.  Offsets are rear and top.  They cannot up armor those without making the tank too heavy.  ERA will work but again it was normally mounted forward. So the reality is that a single well placed M483 can destroy a tank, it is just a probability game.

If anything tanks in CM are too robust. We have already seen a lot of evidence of the effect of HE artillery on modern armor and it isn’t pretty.

[Anthony P.]

Quite agreed. Chechnya does have its reputation for RPG attacks from balconies and roof tops but even so, I'd be surprised if those weren't simply more common than usual, as opposed to consituted a majority of attacks. Even in the best of circumstances, Chechnyan RPG attacks certainly weren't entirely comprised of attacks from above, whereas DPICM attacks are.

I guess that there's potentially another variable specific to Chechnya which isn't applicable to DPICM: the higher need to score a catastrophic kill against a tank which you are in direct combat with in a city as opposed to when targeting a tank with indirect fires. A T-72 across the street in Grozny might have its optics smashed and one or even two crewmen out of action... but if it's still able to traverse and fire its 125mm gun, it'll be a potent threat (and you likely won't even know about the optics or the casualties inside the tank) and so you'll keep shooting RPGs at it until it stops shooting 125mm HE shells at everything in sight. That T-72 might even have its radio, sights and weapons all destroyed, but simply seeing the 44t monster still moving within a hundred meters of you is likely still terrifying, so you'll keep shooting RPGs at it until it stops moving. The tank might be immobilised and you'll know it, but if it can still traverse and fire, you'll definitely keep shooting RPGs at it because both you and its crew know that they can't expect any mercy if they bail out, so they'll fight until dead or rescued.

Things won't be quite so dramatic if a DPICM bomblet has destroyed even just the gunner's sights when the T-72 got caught in the middle of a field as the battalion was forming up for an attack: unless it's a "Centurions on the Golan heights in 1973" kind of situation, that tank's probably gonna be pulled out of the attack without any further discussion.