Vehicle protection from artillery shells

[HerrTom]

11 hours ago, John Kettler said:

TheForwardObserver,

Do you by any chance have any sort of frag size and weight breakdown for when 155 mm HE PD detonates? Haidul talks about a heavy fragment ripping through the side of a BMP and setting it ablaze, which I got me curious. Also, I recall an incident (during the SAE, maybe) in which a large frag from 155 mm HE PD, much to the surprise of the testers, speared right through the turret side (didn't go clean into it, but stuck partially into the interior, causing spall for sure) of what I recall as being an M60, though that may well have been a M46 or M47.  Any idea how I can get a copy of the full SAE? Would love to read it.

Regards,

John Kettler

 

I've looked in vain for the SAE results. My guess is the detailed results may still be classified, though it's curious the artillery article uses images and data from it. Maybe it's a FOIA request away...

I also found a breakdown of fragment weight and velocity by angle somewhere. I'll post it when I find it.

Edited April 14, 2017 by HerrTom

[HerrTom]

@John Kettler I found the document:

WARHEAD PERFORMANCE CALCULATIONS FOR THREAT HAZARD ASSESSMENT

Document # ADA509688

In particular, from page 5:

 

When I have the time and motivation, I'm going to plug away at some of the (extensive) data you presented in your previous links and attempt to make a model of fragment penetration according to:

http://www.globalsecurity.org/military/library/report/1997/penetration_equations.pdf

We'll see what we find. 

[John Kettler]

HerrTom,

I'm quite surprised how well the Mott and Held formulations (whatever they are) track. Must say, though, if I'm reading the right chart correctly, I don't see any fragment greater than 40-45 grams (it is grams, right?). How is such a thing possible? How do I reconcile such puny fragments with the account of a frag which speared right through the side of a tank turret? That is flatly impossible for something that weighs ~4 x what a .45 ACP bullet weighs. Got that weight from this great and withering dissection of the .45 ACP and the unbelievably useless Thompson-LaGarde experiments some/many in the gun community still deem holy writ. 

This neatly illustrates one of my pet peeves regarding nomenclature projectiles resulting from shell or mortar bomb detonation. I fear, though, the war is lost!

http://www.history.army.mil/html/faq/shrapnel.html

More topically, here is what the frags look like from a WW II German 105 mm HE shell. 

http://imgur.com/gallery/C62l4

Jackpot!

TOP 2-2-722

Fragment Penetration of Armor

US Army Test and Evaluation Command

15 March 1983

This has a wealth of material on the characteristics, velocities and frags per steradian as a function of spray angle for the 105 mm and 155 mm HE shells. Am off to find the white coated men with large butterfly nets and a straitjacket in the van, for I fear you'll be needing them once you see this, especially B-2.

http://www.dtic.mil/dtic/tr/fulltext/u2/a125824.pdf

Also found this gem. What's great about it is that it's showing 155 mm frags which are quite substantial relative to what you found. The IED simulator is the very shell you're analyzing. See Figure 2 which shows fragment weight distribution. There are some hefty frags plotted.

23RD INTERNATIONAL SYMPOSIUM ON BALLISTICS TARRAGONA, SPAIN 16-20 APRIL 2007

EXPERIMENTAL SIMULATION OF FRAGMENTATION EFFECTS OF AN IMPROVISED EXPLOSIVE DEVICE

A. Karpenko1 and M. Ceh2

1. 1  Armatec Survivability Corp. 120 Falcon St. London Ontario N6A2K3 Canada,
   Phone: +1 519 659 7531 Fax: +1 519 659 6804 e-mail: engineering@armateconline.com

2. 2  Defence Research and Development Canada – Suffield, P.O. Box 4000, Station Main Medicine Hat AB T1A 8K6 Canada, Phone: +1 403 544 4391 Fax: +1 403 544 4821 e-mail: matt.ceh@drdc-rddc.gc.ca 

3. http://www.ciar.org/ttk/mbt/papers/isb2007/paper.x.isb2007.TB67.experimental_simulation_of_fragmentation_effects_of_an_improvised_explosive_device.karpenko_ceh.2007.pdf

4. Further to the point, it appears that in 2003 in Iraq some version of the SAE tests was conducted and got the same contrarian results as in the 1988 tests. Maybe The ForwardObserver can dig something up on the 2003 tests. Please see the OP for more info.
    

   Regards,

5. John Kettler

 

 

 

Edited April 17, 2017 by John Kettler

[Armorgunner]

18 hours ago, John Kettler said:

HerrTom,

I'm quite surprised how well the Mott and Held formulations (whatever they are) track. Must say, though, if I'm reading the right chart correctly, I don't see any fragment greater than 40-45 grams (it is grams, right?). How is such a thing possible? How do I reconcile such puny fragments with the account of a frag which speared right through the side of a tank turret? That is flatly impossible for something that weighs ~4 x what a .45 ACP bullet weighs. Got that weight from this great and withering dissection of the .45 ACP and the unbelievably useless Thompson-LaGarde experiments some/many in the gun community still deem holy writ. 

This neatly illustrates one of my pet peeves regarding nomenclature projectiles resulting from shell or mortar bomb detonation. I fear, though, the war is lost!

http://www.history.army.mil/html/faq/shrapnel.html

More topically, here is what the frags look like from a WW II German 105 mm HE shell. 

http://imgur.com/gallery/C62l4

Jackpot!

TOP 2-2-722

Fragment Penetration of Armor

US Army Test and Evaluation Command

15 March 1983

This has a wealth of material on the characteristics, velocities and frags per steradian as a function of spray angle for the 105 mm and 155 mm HE shells. Am off to find the white coated men with large butterfly nets and a straitjacket in the van, for I fear you'll be needing them once you see this, especially B-2.

http://www.dtic.mil/dtic/tr/fulltext/u2/a125824.pdf

Also found this gem. What's great about it is that it's showing 155 mm frags which are quite substantial relative to what you found. The IED simulator is the very shell you're analyzing. See Figure 2 which shows fragment weight distribution. There are some hefty frags plotted.

23RD INTERNATIONAL SYMPOSIUM ON BALLISTICS TARRAGONA, SPAIN 16-20 APRIL 2007

EXPERIMENTAL SIMULATION OF FRAGMENTATION EFFECTS OF AN IMPROVISED EXPLOSIVE DEVICE

A. Karpenko1 and M. Ceh2

1. 1  Armatec Survivability Corp. 120 Falcon St. London Ontario N6A2K3 Canada,
   Phone: +1 519 659 7531 Fax: +1 519 659 6804 e-mail: engineering@armateconline.com

2. 2  Defence Research and Development Canada – Suffield, P.O. Box 4000, Station Main Medicine Hat AB T1A 8K6 Canada, Phone: +1 403 544 4391 Fax: +1 403 544 4821 e-mail: matt.ceh@drdc-rddc.gc.ca 

3. http://www.ciar.org/ttk/mbt/papers/isb2007/paper.x.isb2007.TB67.experimental_simulation_of_fragmentation_effects_of_an_improvised_explosive_device.karpenko_ceh.2007.pdf

4. Further to the point, it appears that in 2003 in Iraq some version of the SAE tests was conducted and got the same contrarian results as in the 1988 tests. Maybe The ForwardObserver can dig something up on the 2003 tests. Please see the OP for more info.
    

   Regards,

5. John Kettler

 

 

 

Very interesting reading in the link. Thanks John.

[HerrTom]

@John Kettler I think the scale on mass may be grains, since ballistics people can't be bothered to use even the imperial units we American measurement pariahs use. That would place the largest fragment 15x larger than you said. Or 60x as much as a .45ACP bullet.

EDIT: Bah, I'm wrong. I even got the conversion way wrong!    Interesting question... This requires more research.

Edited April 18, 2017 by HerrTom

[John Kettler]

HerrTom,

Considering the utter, complete and yet to be understood by me hash I made of figuring out the power to weight ratios for the M1A2 Abrams and T-90AM (or whatever the right designator is), I'm certainly not going to point fingers if you erred in your conversion of units. Also, I believe I may've not properly understood that story about the fragment spearing through the side of the turret. My mental picture was of a fragment so large it protruded from both sides of the turret, for it could well have been a fragment not extending above the surface on the outside, but protruding into the interior. Obviously, there would be some sort of BAE from this.

Regards,

John Kettler

[MikeyD]

Lets not forget 'reporting bias'. Nobody takes photos of that tank that got hit by a mortar/artillery round and kept rolling.

There's also reporting bias in the other direction. I'm reminded of the first Stryker to be hit by an IED during Stryker Brigade's initial deployment from Kuwait up to Samarah. Completely destroyed the vehicle. The Pentagon claimed, though, that the Stryker wasn't destroyed by the IED but by the stored sachel charges it was carrying that were ignited by the engine fire that the IED had caused. But NOT by the IED. Which is like saying the T-64 wasn't destroyed by the artillery hit but by the ammo cassette cooking-off. A distinction without much of a difference.

Edited April 18, 2017 by MikeyD

[IICptMillerII]

On 4/17/2017 at 6:33 PM, HerrTom said:

@John Kettler I think the scale on mass may be grains, since ballistics people can't be bothered to use even the imperial units we American measurement pariahs use. That would place the largest fragment 15x larger than you said. Or 60x as much as a .45ACP bullet.

EDIT: Bah, I'm wrong. I even got the conversion way wrong!    Interesting question... This requires more research.

This is my primary point of skepticism: artillery fragments tend to be smaller than a .50 caliber round (in most cases, and depending on the size and type of shell, etc) Based on that, and physics, if a .50 cal round cannot penetrate the side of a tank turret, then how could a smaller fragment hole to do so? Even if it's moving faster, its lower mass means less kinetic energy, which makes it even harder to cause a penetration. Just explaining my reasoning. 

However I am extremely interested in where you are taking this research @HerrTom. If you're able to pull data that shows that artillery generally is able to produce fragments larger than .50 cal rounds with similar ballistics, then I think you may be onto something. According to the data @shift8 found, most artillery fragments are smaller than .50 cal rounds and have reduced ballistic power as a result, which leads to the very small chances of penetration. But if documentation is found that directly contradicts this, I'll be more than happy to change my mind on this whole debate. 

[Haiduk]

46 minutes ago, IICptMillerII said:

This is my primary point of skepticism: artillery fragments tend to be smaller than a .50 caliber round

HE (not fragment) shells as a rule created different fragments - from large to tiny, all depends from material of shell, its features for fragments creation and brisance.

Here examples of different HE shells fragments:

120 mm or 122 mm

 

122 mm

Possibly from Grad

Looks like 152 mm

And even so...

[Armorgunner]

1 hour ago, IICptMillerII said:

This is my primary point of skepticism: artillery fragments tend to be smaller than a .50 caliber round (in most cases, and depending on the size and type of shell, etc) Based on that, and physics, if a .50 cal round cannot penetrate the side of a tank turret, then how could a smaller fragment hole to do so? Even if it's moving faster, its lower mass means less kinetic energy, which makes it even harder to cause a penetration. Just explaining my reasoning. 

However I am extremely interested in where you are taking this research @HerrTom. If you're able to pull data that shows that artillery generally is able to produce fragments larger than .50 cal rounds with similar ballistics, then I think you may be onto something. According to the data @shift8 found, most artillery fragments are smaller than .50 cal rounds and have reduced ballistic power as a result, which leads to the very small chances of penetration. But if documentation is found that directly contradicts this, I'll be more than happy to change my mind on this whole debate. 

Although most of the fragments are smaller. Still, a non-inconvenient part is bigger, and some a lot much bigger. Now the fragments fly in all directions, so the risk of a vehicle being hit by one decreases dramatically with the distance, so does the speed of the fragments. But under an artillery barrage, a few of the big ones will hit AFV´s at somewhat close range/high speed. With a much higher kinetic energy than a .50.

I have a personal collection of larger fragments from Hangö in the southern Finnish archipelago. From Russian Artillery, and mortars from WW2.

 

 

 

 

 

[Armorgunner]

3 minutes ago, Haiduk said:

HE (not fragment) shells as a rule created different fragments - from large to tiny, all depends from material of shell, its features for fragments creation and brisance.

Here examples of different HE shells fragments:

120 mm or 122 mm

 

122 mm

Possibly from Grad

Looks like 152 mm

And even so...

Thats the way my fragments looks like in my collection from Hangö, even though mine are rusty.

[IICptMillerII]

Thanks for the pictures @Haiduk and @Armorgunner

I want to quickly make something clear that has been a continued point of misunderstanding; I am talking specifically about the effects of artillery against tanks. 

I have no doubt that artillery can wreak havoc on AFVs/IFVs, trucks, jeeps, buggys, cars, humvees, ATVs, etc etc.

My primary point of skepticism is about the effects of HE artillery against tanks. Just want that to be extremely clear. 

Looking forward to the results of @HerrTom research. 

[Haiduk]

For example, I have found next data for fragments OF-49 120 mm mortar shell for 2S9 Nona: number of fragments up to 3500, mass of fragments 0,5...1,5 kg, velocity of fragments 1800 m/s, guaranted armor penetration by fragments; 8 mm from 15-20 m and 12...14 mm from 7-10 mm.

If we say about T-64, then this close explosions can penetrate thin lower side hull armor between tracks (25 mm) and rear hull with hit and ignition of engine.

[Armorgunner]

3 hours ago, IICptMillerII said:

Thanks for the pictures @Haiduk and @Armorgunner

I want to quickly make something clear that has been a continued point of misunderstanding; I am talking specifically about the effects of artillery against tanks. 

I have no doubt that artillery can wreak havoc on AFVs/IFVs, trucks, jeeps, buggys, cars, humvees, ATVs, etc etc.

My primary point of skepticism is about the effects of HE artillery against tanks. Just want that to be extremely clear. 

Looking forward to the results of @HerrTom research. 

It was good that you made it clear. Now I see that it was just tanks you wrote in your previous post.

Of course, Tanks are often much better protected. But at airburst detonations, the top armor is not very thick. And there are always weak points even on the side.

Against the latest APFSD-T and the biggest Heat warheads. The front has weakpoints of 20-50% on all modern tanks. On some, the gaps will be even wider after a first hit.
In all sites that compare armor thickness, they always compare the thickest armored parts. Not the weak points. Which is quite large on many tanks.

When Sweden had the competition for a new tank in the early 90´s. The requirement was, that with a thick Swedish made additional Mexas-H armor. The frontal 30 degree would withstand an impact of a determined threat level, at least on 70% of the frontal 30 degree aspect. It got a little better than the requirements. The Swedish made Mexas-H armor was tested on the M1A2, and Leclerc to. But still there were weak points around 20-30% against the highest threat levels.

The biggest weakness is clearly the roof of a tank. Some countries have made the roofs thicker, like Sweden on Strv 122. But there are large weakpoints there too, just not over the turret crew compartment. There will always be a weakpoint where a lucky (Luke) big fragment can penetrate.

Edited April 19, 2017 by Armorgunner

[Erwin]

Am amazed how thick some of those shell fragments are.  Now I understand why they weigh so much.

[Armorgunner]

6 minutes ago, Erwin said:

Am amazed how thick some of those shell fragments are.  Now I understand why they weigh so much.

If you get hit by one of those in close range, your Flak west need to be of quite good quality

[IICptMillerII]

22 minutes ago, Armorgunner said:

It was good that you made it clear. Now I see that it was just tanks you wrote in your previous post.

Of course, Tanks are often much better protected. But at airburst detonations, the top armor is not very thick. And there are always weak points even on the side.

Against the latest APFSD-T and the biggest Heat warheads. The front has weakpoints of 20-50% on all modern tanks. On some, the gaps will be even wider after a first hit.
In all sites that compare armor thickness, they always compare the thickest armored parts. Not the weak points. Which is quite large on many tanks.

When Sweden had the competition for a new tank in the early 90´s. The requirement was, that with a thick Swedish made additional Mexas-H armor. The frontal 30 degree would withstand an impact of a determined threat level, at least on 70% of the frontal 30 degree aspect. It got a little better than the requirements. The Swedish made Mexas-H armor was tested on the M1A2, and Leclerc to. But still there were weak points around 20-30% against the highest threat levels.

The biggest weakness is clearly the roof of a tank. Some countries have made the roofs thicker, like Sweden on Strv 122. But there are large weakpoints there too, just not over the turret crew compartment. There will always be a weakpoint where a lucky (Luke) big fragment can penetrate.

All good points. 

My main point has been that HE artillery is not an optimal tool to use to destroy tanks. 

If you dump a battalions worth of 155s on a stationary Abrams (or any other modern tank for that matter) you're going to kill it, as one of the shells will find a weak spot on the armor, or a fragment of sufficient size will do the same.

However, the tank is not going to sit there and allow itself to get pounded by artillery. Once it knows it's being targeted/bracketed by artillery it's going to move. After all one of the biggest and primary advantages a tank brings to the battlefield is mobility and firepower. In the case of avoiding being destroyed by artillery, it relies on the mobility advantage. This obviously is no longer the case for a tank that has lost its mobility, whether it be due to being fracked by the artillery, being in a permanent fortified position (doctrinal folly, but a topic for a different discussion) or if the ones shooting the artillery have a pre registered target on the tank and are able to hit it fast enough, with enough shells to knock it out. 

So again, just to reiterate for the sake of clarity, I DO NOT think that tanks are invincible against artillery. I DO think that artillery is the wrong tool to kill a tank with because all the tank must do to survive is move. 

[Armorgunner]

25 minutes ago, IICptMillerII said:

All good points. 

My main point has been that HE artillery is not an optimal tool to use to destroy tanks. 

If you dump a battalions worth of 155s on a stationary Abrams (or any other modern tank for that matter) you're going to kill it, as one of the shells will find a weak spot on the armor, or a fragment of sufficient size will do the same.

However, the tank is not going to sit there and allow itself to get pounded by artillery. Once it knows it's being targeted/bracketed by artillery it's going to move. After all one of the biggest and primary advantages a tank brings to the battlefield is mobility and firepower. In the case of avoiding being destroyed by artillery, it relies on the mobility advantage. This obviously is no longer the case for a tank that has lost its mobility, whether it be due to being fracked by the artillery, being in a permanent fortified position (doctrinal folly, but a topic for a different discussion) or if the ones shooting the artillery have a pre registered target on the tank and are able to hit it fast enough, with enough shells to knock it out. 

So again, just to reiterate for the sake of clarity, I DO NOT think that tanks are invincible against artillery. I DO think that artillery is the wrong tool to kill a tank with because all the tank must do to survive is move. 

I agree to you in that artillery is not the number one tool to use, in a all out war. But as shown in Ukraine, it is a very useful tool. Even with HE.

And i agree with you, that as long as a tankforce is Maneuvering, it is almost untouchable from HE. But at some point, the tanks are not maneuvering. And if there is an Artyspotter/Spetsnaz/SF/ or anybody with a radio in ocular contact , there will be the rain of hell over those tanks. As those are quite Priority targets. And the casualties among the tanks, will be greater IRL, than in CM. Thats for sure.

Edited April 19, 2017 by Armorgunner

[Armorgunner]

My biggest complain for CM Vs Artillery is. IRL A direct hit, or a very close one of a 155mm would destroys sights, prismas, and about everything that makes the tank dangerous. M-Kill in other words. And sometimes even kill it. But in CM, tank are almost totally imune. Direct non killing hit in CM, almost no damage, if non at all. Tell that to all the tankcrews in eastern Ukraine. I think they would love that truth.

This is said to be a T-64BV after a direct frontal hit of a 125mm HE. Berkut/Omon unit taking cover behind the Abandoned tank. 75% of the ERA is gone, the driver needs to button up to see. Aiming, through open breech?

 

 

 

Edited April 20, 2017 by Armorgunner

[HerrTom]

Wow look at those holes in the track covers.  That must have been noisy.

3 hours ago, IICptMillerII said:

My main point has been that HE artillery is not an optimal tool to use to destroy tanks. 

I'm not sure anyone has been arguing against that.  I think the main argument is that in the chance that artillery lands nearby tanks and other AFVs, they appear to be less vulnerable in CMBS than they should.

Regarding modeling, I haven't had much time to do it so far, but I hope to free up this weekend.  I'm just as interested to see the results - still have to figure out how to present any data in a useful and legible fashion.

[IICptMillerII]

7 minutes ago, HerrTom said:

Wow look at those holes in the track covers.  That must have been noisy.

I'm not sure anyone has been arguing against that.  I think the main argument is that in the chance that artillery lands nearby tanks and other AFVs, they appear to be less vulnerable in CMBS than they should.

Regarding modeling, I haven't had much time to do it so far, but I hope to free up this weekend.  I'm just as interested to see the results - still have to figure out how to present any data in a useful and legible fashion.

I was just clarifying my point because I feel a lot has been tossed around and lost in translation in the three or so threads on this topic. 

Very interested to see what you're able to come up with!

[DougPhresh]

I'm fondly remembering doing anti-tank drill in Artillery School. It was a hell of a lot of work, and most of us thought it was futile, but anything that gets hit with a 155 is going to have a very bad day. I wouldn't expect optics or antenna to be in good shape after an airburst, and the more complex systems like APS or Shtora even moreso.

[A Canadian Cat]

15 hours ago, Armorgunner said:

My biggest complain for CM Vs Artillery is. IRL A direct hit, or a very close one of a 155mm would destroys sights, prismas, and about everything that makes the tank dangerous. M-Kill in other words. And sometimes even kill it.

Right, and that has been my experience in CM too - lots of mission kill'ed tanks and the occasional dead one

15 hours ago, Armorgunner said:

But in CM, tank are almost totally imune. Direct non killing hit in CM, almost no damage, if non at all.

This is not my CM experience at all.

[Muzzleflash1990]

I mirror what Armorgunner says for all vehicles. My anecdotal experience, for all vehicles, is that either the round lands close enough to completely destroy the vehicle, or it lands far enough not to do any damage at all. I find it exceedingly rare (like unicorn rare), that a vehicle suffers partial damage, and when it does it is almost only tracks/wheels that go from very green to tiny bit less green - same as occasionally happens when you drive through a wooden fence in the game.

When I recently did some test roughly 10 times against the Tunguska in the 3rd tutorial mission using 155mm arty, any round either, hit or landed close enough to immediately destroy the vehicle, or landed far enough away to do any damage at all. This, with the tiny track damage mentioned earlier, is an outlier. http://imgur.com/a/mCOaZ . None, of the tubes, or the radar itself, has any inkling of damage. Tunguska is 8m long, that will put the rounds at roughly 8-15m distance.

Edited April 20, 2017 by Muzzleflash1990

[Armorgunner]

1 hour ago, IanL said:

Right, and that has been my experience in CM too - lots of mission kill'ed tanks and the occasional dead one

This is not my CM experience at all.

Are your sure we played the same game?? I did a "new for the day" artillery bombardment of a sittingduck tankforce, and they were in quite good shape after 3 min of heavy bombardment from 18 155mm. 4 out of 12 was imobilized, but only one of those had damage to some subsystems.