Jump to content
HerrTom

Vehicle protection from artillery shells

Recommended Posts

I found an interesting "scan" of a report from the 1960s about the protection steel plates provide against artillery shells. It can be found here:

http://tanks.mod16.org/2014/03/10/report-on-protection-from-fragments-from-he-ammunition/

Offers more... er.... ammunition on the debate on artillery's effectiveness against armored vehicles.

Also I believe @TheForwardObserver has posted the following article here before: ("Who Says Dumb Artillery Shells Can't Kill Armor?"

http://imgur.com/gallery/gIjCo

Perhaps also of interest is the STANAG 4569 standards for armor protection - though it's not clear immediately what "protection" means in their definition - does it mean unlikely to penetrate or impossible?  Usually these kinds of standards documents have definitions to deal with this kind of clarity problem, but I didn't see anything.

https://www.unops.org/ApplyBO/File.aspx/4569eed02.pdf?AttachmentID=52d5a7b6-37ad-49bc-b18c-c468ea81787a

----

I wanted to start this thread to build a fact-based argument on how artillery performs in Combat Mission so we can continue to strive for accuracy in simulation (or something like that!).  I haven't had time to read the first report in detail, but I realize it may be limited in utility for the discussion on armored vehicles since it talks about steel armor only.

The big thing I've gathered here is the importance of fragments - and especially the variability.  This seems to be one of the things that's missing from CM.  Using the fragmentation density, we could construct a probability function of a fragment hitting a given area at any radius, and using data from tests like above we can also generate a distribution of penetrations.  In my mind, this (as far as I know) relatively simple method may be a good way of "simulating" fragmentation in-game, especially compared to the brute-force approach of just shooting fragments everywhere!

I'm a little too busy/tired during the week to really pursue this further, but I'd love to see what else we can dig up.  Hopefully this weekend I can put together some plots to show what I'm talking about.

Share this post


Link to post
Share on other sites
10 hours ago, HerrTom said:

The big thing I've gathered here is the importance of fragments - and especially the variability.  This seems to be one of the things that's missing from CM.  Using the fragmentation density, we could construct a probability function of a fragment hitting a given area at any radius, and using data from tests like above we can also generate a distribution of penetrations.  In my mind, this (as far as I know) relatively simple method may be a good way of "simulating" fragmentation in-game, especially compared to the brute-force approach of just shooting fragments everywhere!

I'm not sure missing is really the right word. Yes, they do not track every fragment.  I believe we have established there is in fact a model for fragment dispersion and probability to hit. That's why you see sometimes see a solider unscathed 10m from a blast meanwhile their buddy 20m away goes down.

Feel free to discuss if what we have in game now matches reality etc. that's a noble goal.

Share this post


Link to post
Share on other sites

I'll try to find the link, but there's a British MoD study about artillery effectiveness which correlates fragment size to incapacitation/wounding/killing of infantry. The amount of fill (and type) has to be balanced with the shell thickness to produce the optimal sized fragments.

Too brittle of a shell and too thin, coupled with an overfill of HE results in many tiny fragments. They don't kill well enough. On the other side, too thick of a shell and too small of a filler makes just a few big chunky fragments. They'll kill...but the odds of hitting someone are too low. The British seemed to think their 25lber shells were just right.

WRT anti-armor effects, larger fragments seem to be needed for penetration or damage. Breaking out/determining the fragment sizes produced by the shells is important, as is the speed with which they are driven. Average numbers won't help. 10,000 1 gram fragments mixed among 100 1,000 gram fragments means an average weight of about 11 grams. It's pretty easy to shrug off 11 gram fragments. (If we just looked at average weights.) The 1 kg (1,000 gram) fragments would be far more dangerous to the vehicles.

There's a Ft. Sill/US Armor magazine pdf which discusses how a battery of 155mm howitzers can destroy a Soviet tank formation. The pictures were impressive, but it was a pro-artillery publication, after all.

My point to all this? Real world data of fragmentation would be a necessary first step. Finding that arcane data seems a bit difficult.

Share this post


Link to post
Share on other sites

Thanks Ian. I hadn't really noticed that. Good to know!

c3k, the Ft Sill publication should be the second link in my post. I would have linked to the pdf oh the army website but it's currently having routing issues I think. On the rest, I agree, a good model of this problem needs to be stochastic in some sense to capture the immense variability.

I seem to remember someone saying that explosives on this game were scaled down, at least for infantry, due to engine limitations with spacing. This presents a bit of a conundrum: Do we scale it's effect on vehicles to the same level? Do we present realistic effects for vehicles, but then be inconsistent in effect between target types?

Maybe the new engine's infantry behavior has mitigated the original problem?

Share this post


Link to post
Share on other sites

I have an anecdote for when CMBS was released. In the tutorial I ordered an ordinary HE strike against the 2K22 Tunguska. 6 rounds landed around, in an almost perfect hexagonal pattern with the vehicle being in the center, and all rounds roughly  8~12m away from the vehicle. For a vehicle so lightly armored, I hoped it would be neutralized, but at least thought it should be damaged, like the missile tubes. After action review showed it remained fully operational with zero damage to all components. By STANAG 4569 it must have had level 5/6 protection.

Share this post


Link to post
Share on other sites
3 hours ago, HerrTom said:

I seem to remember someone saying that explosives on this game were scaled down, at least for infantry, due to engine limitations with spacing. This presents a bit of a conundrum: Do we scale it's effect on vehicles to the same level? Do we present realistic effects for vehicles, but then be inconsistent in effect between target types?

Steve has mentioned this HE effect on infantry reduction in the past. Vehicles don't need any special treatment (other than by us players to remember not to bunch them up - that's on us). I don't see any reason why the game could not model the effects on vehicles one way and on infantry a bit different. The trick is to figure out what should happen and then see if that is happening in the game or not. I am curious to see what sources people find and what they say.

 

3 hours ago, HerrTom said:

Maybe the new engine's infantry behavior has mitigated the original problem?

v4 engine has not changed the infantry spacing that much. What the v4 engine changes did was stop guy from running in a conga line one after another but they are still slightly closer than typical for RL.

Share this post


Link to post
Share on other sites
10 minutes ago, Muzzleflash1990 said:

I have an anecdote for when CMBS was released. In the tutorial I ordered an ordinary HE strike against the 2K22 Tunguska. 6 rounds landed around, in an almost perfect hexagonal pattern with the vehicle being in the center, and all rounds roughly  8~12m away from the vehicle. For a vehicle so lightly armored, I hoped it would be neutralized, but at least thought it should be damaged, like the missile tubes. After action review showed it remained fully operational with zero damage to all components. By STANAG 4569 it must have had level 5/6 protection.

Wow that is some luck there. Are you talking 155mm artillery here or 120mm mortars?

I have dropped a lot of 155 on to BMPs, T90s and M1s. My general rule is this: if you want it dead the majority of the time, hit the BMP (Tungusak would be the same) with two precision shells, the T90 with three and the M1 with more than three if you can. Doing that leads to a dead vehicle the majority of the time and and useless vehicle a big chunk of the rest. True some times the buggers manage to get lucky and keep driving around but not often.

I have never seen a pretty little hex pattern around the vehicle. And I have never seen a BMP stay running if hit by a 155mm artillery shell not one. T90s and M1 can survive a direct hit but its not a sure thing that they will.

Share this post


Link to post
Share on other sites

I certainly felt it was lucky. I did not use precision, only ordinary 155mm HE fire since I wanted to see whether it would be effective. And yes the hex pattern was quite unusual. I just fired BS up again to try again. However, this time just two close shots - landing exactly same place, roughly 6-8m from the rear of the vehicle disabled - or rather the crew certainly felt safer outside the vehicle and dismounted. Because of that I could not see the damage. The second Tunguska got roughly 4 direct hits from 8 shots using ordinary point fire and was also not available for inspection.

Edited by Muzzleflash1990

Share this post


Link to post
Share on other sites
4 hours ago, c3k said:

There's a Ft. Sill/US Armor magazine pdf which discusses how a battery of 155mm howitzers can destroy a Soviet tank formation. The pictures were impressive, but it was a pro-artillery publication, after all

c3k,

The article references a series of live fire trials (Soviet Artillery Effectiveness) to establish the validity or lack thereof regarding Russian artillery norms to achieve a specified level of damage to various defined targets. The expectation going in was that the Russian numbers, based on three different US predictive models, were grossly overstated when it came to firing on armor, but look at what a mere 56 rounds, in a shoot conducted three times using Russian calculations and procedures, did vs M48 tanks. Bold mine.

"The first test was conducted in 1988. Researchers confirmed that the US 155-mm HE round was a reasonable surrogate for the Soviet 152-mm HE round. An M109 155-mm howitzer battery using Soviet fire direction and gun procedures fired the test. The targets were manikins placed in fighting positions, US trucks, M113 and M557 armored vehicles, and M-48 tanks. Several different computer models were used to predict results. The test was fired three times using 56 HE rounds with point-detonating (PD) and variable-time (VT) fuzes. The resulting effects on the trucks and personnel were close to model predictions. However, the effects on the armored vehicles and tanks were significantly higher than model predictions. The model predicted 30 percent damage to armored vehicles and tanks; however, 67 percent damage was achieved. Fragmentation from the HE rounds penetrated the armored vehicles, destroying critical components and injuring the manikin crews. (See an example of such damage in Figure 1.) In addition, the HE fragmentation damaged tracks, road wheels, and tank main gun sights and set one vehicle on fire. Interestingly enough, none of the damage to the armored vehicles or tanks was the result of direct hits—all the damage was caused by near hits. This test confirmed that US Army models did not accurately portray artillery effectiveness. Direct hits were not required to damage tanks and other armored targets."

The expectation going in was that the Russian norms to destroy armor (50% losses) were ridiculously low: that only the 30% (temporary neutralization level) was achievable, but no fewer than three iterations of the test showed it was the US artillery community which had been wrong all along. But wait. There's more.

"A direct hit with an HE round with a PD fuze consistently destroyed the various target vehicles. Near hits damaged or destroyed road wheels, tracks, main gun sights and vision blocks. Aerial bursts of HE rounds with VT fuzes damaged or destroyed gun barrels, vision blocks, antennas, sights and engines and destroyed anything stored on the outside of the vehicle. (See Figure 2.)"

A single direct hit by 155 mm HE PD (surrogate for Russian 152 mm HE PD) kills an M48 outright!  Near misses cause all sorts of havoc, and HE VT, largely ineffective in the game vs armor, was found in live fire to be able to generate partial or full F-Kills and M-Kills!

The article, which I've read, wasn't pro-artillery. Instead, it delivered a shattering blow to the long held individual and group perceptions of the Armor community. There was also some horrifying news for the Infantry community, too. Excerpts taken from below.

http://forums.eugensystems.com/viewtopic.php?t=59283

Regards,

John Kettler

Share this post


Link to post
Share on other sites

I would just like to quickly add that a test from the 1960s, or artillery tests done on vehicles from the 1960s (M48s/M60s/M113s) are very much out of date. Modern vehicles and armor are different, and essentially harder to kill. Just because a 155mm round to the turret of an M48 can knock that vehicle out, does not mean that same effect applies to every tank that has ever existed ever. 

I've stated my interpretation of the data in a few threads now. Essentially Combat Mission gets it right more than it doesn't. However if someone can post recent data (within the past 2 decades) using recent equipment (modern tanks/IFVs opposed to early Cold War vehicles) I am more than happy to revise my position. 

Edited by IICptMillerII

Share this post


Link to post
Share on other sites

The tests from the article were a 4-year-long study starting in 1988.

As for the 1960 study, which you seem to have confused, steel is steel. They ran tests on plates, not vehicles. Yes, modern vehicles have more complex armor in certain areas, but others are still just steel.

I'm trying to find more on NATO standards for testing armor as well as looking to see what the USSR let leak. Hopefully I can find something juicy.

Edit: You seem to know something we don't. By all means show us a source to back up what you say. I want to figure out how accurate the game is. My gut says something is wrong, but that doesn't mean anything in this kind of argument.

Edited by HerrTom

Share this post


Link to post
Share on other sites

@IICptMillerII  Can you provide at least one real experience you've had with field artillery or tanks or explosions for that matter which informs your opinions on what is and isn't realistic when it comes to artillery, tanks, and explosions?  If you're in a position where you're free to confidently discount findings that were at minimum considered relevant in 2002 and published in the USAFTC professional journal for Redlegs I would love to hear about the road you took to get there.

Share this post


Link to post
Share on other sites

IICptMillerII,

I meant to point out the M48s were devoid of the reactive armor overlay found even on much of the roof of Russian and Ukrainian tanks, nor had protective skirts of any sort. Additionally, though I'm not sure, I suspect the level of roof protection isn't as high on an M48 and it is on an Abrams. Does it have DU in the turret top, too? While I'm not at all certain any tank presently operational can survive a direct hit on the turret roof by 152 mm or 155 mm HE PD, especially since 122 mm Kitolov 2M is itself HE PD and officially State accepted as being able to kill any tank out there with a single hit, I do agree that many current AFVs in the game are significantly better protected than the target set covered in the SAE tests. 

Regards,

John Kettler

Edited by John Kettler

Share this post


Link to post
Share on other sites
2 hours ago, IICptMillerII said:

Just because a 155mm round to the turret of an M48 can knock that vehicle out, does not mean that same effect applies to every tank that has ever existed ever. 

 

3 hours ago, John Kettler said:

Interestingly enough, none of the damage to the armored vehicles or tanks was the result of direct hits—all the damage was caused by near hits

 

It was mostly not talking about direct hits.  But I guess is is tough to know how more modern armor might react differently.  but on the other hand a lot of it is still steel.

Edited by cool breeze

Share this post


Link to post
Share on other sites

Ceramics won't be happy, they'll fracture and pulverise under shock. I am not sure that that will significantly affect its ability to resist penetration though. CMCs would fare better than pure ceramics, but not much.

DU and tungsten have a similar problem in their lack of ductility, though they are significantly tougher.

Share this post


Link to post
Share on other sites

As already stated, a very good starting point to improve the modelling of artillery dammage  and shrapnel against vehicle is the Stanag 4569 : https://en.wikipedia.org/wiki/STANAG_4569

Most vehicles in the game have a STANAG rating that can be found easilly on internet. From there it should be possible to tweak the dammage model.

The Stryker for example, is amodified LAV III. The LAV III has a base all-around armour rated Level III and when applied appliqué armour can reach Level IV. Thus, Stryker ingame should have Level IV armour 14,5 proof, at least on the front, which means its armour cannot be penetrated by Shrapnel if the 155mm shell detonate at more than 30m distance. At less than 30m a 155mm shell shrapnel can penetrate and kill the crew/engine, etc.

That being said, all the external optics and weapons can probably be dammaged at further range. But I believe those also have a rating.

Edited by FoxZz

Share this post


Link to post
Share on other sites
On 4/5/2017 at 6:48 PM, TheForwardObserver said:

@IICptMillerII  Can you provide at least one real experience you've had with field artillery or tanks or explosions for that matter which informs your opinions on what is and isn't realistic when it comes to artillery, tanks, and explosions?  If you're in a position where you're free to confidently discount findings that were at minimum considered relevant in 2002 and published in the USAFTC professional journal for Redlegs I would love to hear about the road you took to get there.

Well the problem here isnt the reports, it is the generally inaccurate reading you guys are getting out of it. 

If you actually read the first report, the one on shrapnel, you will find that even 155 HE produced almost no penetrations of even relatively thin steel. That report is nothing but damning to this ridiculous notion that HE is especially effective against armor, in particular tanks. 

The only type of hit that "kills" a tank outright from artillery is a direct hit. Artillery fire can track tanks or otherwise cause external damage, but you need very large quantities of explosives to actually kill one. 

Tanks and other armored vehicles are designed specifically to be relatively immune to non-direct hits from HE. They would otherwise be completely pointless. Even direct he require large calibers in most cases. 

Edited by shift8

Share this post


Link to post
Share on other sites
Just now, Erwin said:

Does the blast effect of nearby HE hurt the crew?

No. 

The exception would be exceptionally large explosions, but at that point your entering the realm of something powerful enough to actually kill the vehicle outright. Like a near miss from a 1000lb bomb or battleship gun. 

Share this post


Link to post
Share on other sites

Page 13 of the Swedish-sourced study says " At 90 foot standoff distance, 100% protection cannot be obtained against... fragments from the 155-mm, HE, M107 projectile using thicknesses of rolled homogenous steel armor of both specification and modified hardness up to and including 1/2 inch."

 

Here's (the only such, oddly enough) image of the BMP-1's armor thickness (Plus a Marder for fun and profit!)

1451251337-marder-bmp-2-armor.jpg

The data in that study would mean that the rear and top armor are not thick enough to protect it from airbursts and groundbursts within 90 feet, or about 30 meters.  Now, not every shell would kill or even penetrate the vehicle - but there's a chance.

At any rate, I'm more inclined to believe the data presented in the real-world tests in the Soviet Artillery Effectiveness study compared to the almost 30-year prior study.  Both provide data, but a different type. :)

Share this post


Link to post
Share on other sites
1 hour ago, shift8 said:

Well the problem here isnt the reports, it is the generally inaccurate reading you guys are getting out of it. 

Interesting that you've been able to ascertain my reading of the article as I've not actually given any of my thoughts on the article.  

Share this post


Link to post
Share on other sites
6 hours ago, shift8 said:

Well the problem here isnt the reports, it is the generally inaccurate reading you guys are getting out of it. 

If you actually read the first report, the one on shrapnel, you will find that even 155 HE produced almost no penetrations of even relatively thin steel. That report is nothing but damning to this ridiculous notion that HE is especially effective against armor, in particular tanks. 

The only type of hit that "kills" a tank outright from artillery is a direct hit. Artillery fire can track tanks or otherwise cause external damage, but you need very large quantities of explosives to actually kill one. 

Tanks and other armored vehicles are designed specifically to be relatively immune to non-direct hits from HE. They would otherwise be completely pointless. Even direct he require large calibers in most cases. 

But since you've included me, maybe re-consider your own reading of the second story there ace, just to round out your perspective on the issue, before we continue and maybe consider providing whatever counter-point or rebuttal to the original findings that Sill's chosen to publish since then in your response.  If you can find one, I mean I assume there's one there right?
http://sill-www.army.mil/firesbulletin/archives/2002/NOV_DEC_2002/NOV_DEC_2002_FULL_EDITION.pdf

Now your argument, as compelling as it was, was actually no more than you stating that the opposite is true because you say so.  You sound like you have solid military experience, but really I don't care, because you don't sound like a FISTER, which would mean you're out of your lane, and which makes it exponentially more bizarre that you're so confident in your analysis and not actively including any caveats in your stated evaluation of the potential for effects-- because not too many folks besides FISTERs are dealing with the answers to these sorts of issues throughout their entire careers, not even Artillery Officers, isn't that funny, they have to go back to the battery, we don't, we're stuck watching the doom end forever!  And you know part of speaking truth to power is not making $h!t up.  But none of that is relevant, what it relevant is that the Army accepts and standardizes your targeting philosophy ASAP, I've seen a lot of variability of SOPs from Battalion to Battalion in my day, and if we just do it your way that'll stop today.

Now I've always tended to look at at the fight multi-laterally, meaning I like to leverage the effects of a variety of platforms with redundant and overlapping capabilities, in order to empower, not restrict the commander--- but your way is good too man!!

As an aside-- remarkably insightful explanation about what tanks and armored vehicles are specifically designed for, you're clearly very bright.  "Relative immunity to non-direct hits from HE," sounds very scientific!  I've never much understood myself what we put the armor there for.  I thought maybe it was for camouflage but woah really heavy camouflage man!

Share this post


Link to post
Share on other sites
13 hours ago, shift8 said:

No. 

The exception would be exceptionally large explosions, but at that point your entering the realm of something powerful enough to actually kill the vehicle outright. Like a near miss from a 1000lb bomb or battleship gun. 

Let's not play dumb please. You made your opinion rather clear when you chastised Miller for having and opinion contrary to what you perceive as correct. 

Share this post


Link to post
Share on other sites
5 hours ago, TheForwardObserver said:

But since you've included me, maybe re-consider your own reading of the second story there ace, just to round out your perspective on the issue, before we continue and maybe consider providing whatever counter-point or rebuttal to the original findings that Sill's chosen to publish since then in your response.  If you can find one, I mean I assume there's one there right?
http://sill-www.army.mil/firesbulletin/archives/2002/NOV_DEC_2002/NOV_DEC_2002_FULL_EDITION.pdf

Now your argument, as compelling as it was, was actually no more than you stating that the opposite is true because you say so.  You sound like you have solid military experience, but really I don't care, because you don't sound like a FISTER, which would mean you're out of your lane, and which makes it exponentially more bizarre that you're so confident in your analysis and not actively including any caveats in your stated evaluation of the potential for effects-- because not too many folks besides FISTERs are dealing with the answers to these sorts of issues throughout their entire careers, not even Artillery Officers, isn't that funny, they have to go back to the battery, we don't, we're stuck watching the doom end forever!  And you know part of speaking truth to power is not making $h!t up.  But none of that is relevant, what it relevant is that the Army accepts and standardizes your targeting philosophy ASAP, I've seen a lot of variability of SOPs from Battalion to Battalion in my day, and if we just do it your way that'll stop today.

Now I've always tended to look at at the fight multi-laterally, meaning I like to leverage the effects of a variety of platforms with redundant and overlapping capabilities, in order to empower, not restrict the commander--- but your way is good too man!!

As an aside-- remarkably insightful explanation about what tanks and armored vehicles are specifically designed for, you're clearly very bright.  "Relative immunity to non-direct hits from HE," sounds very scientific!  I've never much understood myself what we put the armor there for.  I thought maybe it was for camouflage but woah really heavy camouflage man!

Ah here we go with the pseudo appeals to authority in the absence of an actual arguement. 

I've read the pdf you posted years ago. It says nothing remarkable, or out of line with my opinion. But that does not stop people from reading into it what they want.

Additionally, said document was at least in part notable because of a perceived difference in its opinion from previous army standard opinion. Hence, clearly army opinion is not set in stone and subject to criticism. 

You accuse me of making a nonsensical argument, but you typed several paragraphs of arrogant drivel that essentially just spouted "shut up I'm artillery " without actually much else. What else you did say, I am not even certain what you meant. Some nonsense about multi layered perspectives to war. What?

I have no issue with the contents of the data. I take issue with the incorrect interpretation which is being used, as has been argued before, that arty in this game should be some kind of AOE anti tank doom barrage. 

Share this post


Link to post
Share on other sites
12 hours ago, HerrTom said:

Page 13 of the Swedish-sourced study says " At 90 foot standoff distance, 100% protection cannot be obtained against... fragments from the 155-mm, HE, M107 projectile using thicknesses of rolled homogenous steel armor of both specification and modified hardness up to and including 1/2 inch."

 

Here's (the only such, oddly enough) image of the BMP-1's armor thickness (Plus a Marder for fun and profit!)

1451251337-marder-bmp-2-armor.jpg

The data in that study would mean that the rear and top armor are not thick enough to protect it from airbursts and groundbursts within 90 feet, or about 30 meters.  Now, not every shell would kill or even penetrate the vehicle - but there's a chance.

At any rate, I'm more inclined to believe the data presented in the real-world tests in the Soviet Artillery Effectiveness study compared to the almost 30-year prior study.  Both provide data, but a different type. :)

Right but this doesn't mean much. If you read the hard data later in the document, the number of perforations per shell per square foot are measured in the .01 and similar. The chances of a penetration is so low as to be more or less assured for practical purposes. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×