Armor topic

[panzersaurkrautwerfer]

Why the US?

Biggest power on the planet, fairly limited direct repercussions if alienated (US-Russian trade even when things were fairly friendly was modest at best).   China is much more important economically to the US, and while regionally can be a foe/opponent, globally it is neutral-friendly in terms of Russian interests (which is to say the US would be against Russian expansion regardless of where it was, while the China-Russian conflicts are limited more to their shared border, Russian efforts in the Ukraine or Chinese efforts in Africa don't conflict or illicit protests from each other).  

[BTR]

But again there's a big difference in terms of what that LOS is comprised of.  We got a defective fan for an M88A2 engine with microfractures, so after a few hours of operation it dramatically failed and sent bits of fan all over the inside of the engine compartment.  The "after" photos were a sight to behold in terms of large chucks of metal embedded in various parts of the vehicle.  Also a lot of engine compartments by design are open and dead spaces (also rather famously one of the T-34/85 overpenetrations went in the frontal slope and exited out the back of the engine compartment with sufficient violence to force US forces a few hundred meters away to take cover, and there's more than a few T-72s and T-55s with "exit wounds" in Iraq)

Basically where I'm going is if this happened IRL I'd not be totally shocked.  It is an uncommon event, but one that is based in reality.  The frequency of this event in CMBS is by several magnitudes higher than I'd expect to see though, which includes some rather out there situations (I seem to recall a shot that killed two tanks, went through a building then killing and IFV).

To that end it might be more realistic to somehow drop the "two in a row" kills simply because it is uncommon enough to not require simulation, but that's just my take on it.  I don't know how complicated that would be, or if it'd totally bugger actually desired behavior.  

I wasn't debating overmatch as an occurrence, I was skeptical of projectile power to KO another tank afterwards. Especially at 1000+ m. Under 400m, I seem to be getting almost 100% 2x Combo having a T-90AM vs M1A2's. Haven't got a 3x Combo yet :). Not sure how representative of M1A2 side armor this is, but I'll try the same test in reverse.  

Edited December 26, 2015 by BTR

[panzersaurkrautwerfer]

Again, wouldn't entirely rule it out happening once in a blue moon, but it certainly should not happen often. 

If it did not affect other things (one of the things I really like about CMBS is rounds don't just ghost if they miss, so watching a barn 'esplode because a round went wild is pretty awesome) I'd say simply excluding the behavior.  Again while it is not an historically unknown event it is not a behavior that anyone counts on, or expects to occur with any degree of frequency.  

[akd]

Once upon a time I set up a test where an 88 penetrated 8 Stuarts lined up in a row.  Following that and other tests, Charles added some random deviation after through and through penetrations, so that particular insanity is less likely to occur.  Possibly there still needs to be more deviation, and / or maybe much more mass loss.  How differently should a long rod penetrator be treated compared to AP shot / shell when it comes to over penetration?

[Sublime]

Makes sense. If I may though, if you want a boogeyman why not one that if it comes to it you can beat handily, yet still has a lot of prestige money etc. A lot of European HATO countries come to mind.

One last question for panzer.  In my mind theres no doubt at all that until Dec 1991 any overt aggression against NATO would have been met with force.  Do you still believe this is true for ALL NATO members  now? I dont mean an armored thrust at Poland or nukes on London. I mean lets say a certain member state of NATO keeps antagonizing Russia shooting down its planes et etc.   And the Russian response isnt ultra Russia stronk invasion of Turkey  but say cruise missiles. Bombing.    Would the US and more Euro NATO states really amp it up and start bombing Russ airfields etc? Opinion only I know. Just curious to your thoughts.

[BTR]

How differently should a long rod penetrator be treated compared to AP shot / shell when it comes to over penetration?

Heh, I wander if this would be a good thesis question for some material physics student . From what I've seen in simulations perpetrator energy vectors inside the material are not easily changed even if rod material may be. Empirical evidence points to slopes only working against APFSDS when LoS slope thickness is greater than gun caliber from which the penetration was launched. Then something like this happens:

http://i.imgur.com/mm7O3tM.jpg 

In short, long rod perpetrators are a lot more stable in their trajectory post-impact then other AP rounds. 

[panzersaurkrautwerfer]

Makes sense. If I may though, if you want a boogeyman why not one that if it comes to it you can beat handily, yet still has a lot of prestige money etc. A lot of European HATO countries come to mind.

If it's too low a hanging fruit, then the ultra-nationalists will really begin to insist said nation be crushed.  The US is something that Russian realistically will never be able to effectively be ready to fight so it serves very well as a boogyman to pull out.  Also Russia has way more ties to the various European NATO countries, so it'd be bad business to sour those connections, while if Russia and the US never traded again, neither would be too deeply affected.

In regards to the Turkey situation, it's the Ukraine in reverse.  Russia knew exactly how far it could run with the Ukraine without bringing a "hard" response (although it certainly underestimated the bite of the "soft" response).  The Turks certainly worked out how far they could run with vigorously enforcing their air space without bringing in a hard Russian response.  Russia overplayed its hand in bombing Turk allied anti-Assad folks while at the least skirting Turkish airspace (and almost certainly violating it).  Ego saving measures have taken place.  Russia would have to commit an overt act of war to really get at the Turks now, which it will not do as Syria is important, but not important enough to risk a wider war over.  The Turks are in a similar place that they'd really have to flagrantly gun for Russians on the Syrian side of the border to bag another Su-24, and that's well outside of what NATO will support.  

Anyway.  Massive off topic but while Russian and Turkish leaders both play the loose cannons, they're not.  They're well aware of the lines they're trodding on which while there is danger, we're not yet playing for all the marbles if you get my drift.

Anyway.  It would be an awesome physics experiment in terms of sabot behavior post-penetration.  The steady flight pattern post-penetration seems to fit with the way most training sabots mushroom although I'm not sure how well the training round to target/berm impact translates in terms of making both objects much harder.  

[BTR]

To kick the discussion back on its track. Here are glacis compositions for main Soviet medium and main battle tanks. Most of it is fairly common knowledge, but I never really found it amalgamated into one clear visual representation: 

In case BF ever decides to get their cold war theme rolling. 

[John Kettler]

My understanding is that the M829A4, because of increased mass resulting from penetrator thickening, is 200 m/s slower than its predecessor. The thickening of the penetrator was done specifically to prevent defeat by shearing action when encountering advanced ERA before types emerged which applied a shaped charge jet to arriving projectiles. Standard long rod penetrators are very strong in compression but weak in shear. Thus, the M829A4 is designed as a sort of flying battering ram able to smash through the designed ERA threats and underlying armor. Additionally, it takes more force to heave it off axis, which is another ERA effect. Finally, based on diagrams and high speed radiographs I've seen, the old long rod penetrators didn't go straight line when penetrating. Rather, they sort of "J"ed into the armor plate, which is very bad if hit in the glacis, since the penetrator hits, bites into the armor and hooks downward! Since the M829A4 is far less flexible on impact, it should follow a much more straight line path than did prior long rod penetrators.

As for multiple AFV penetrations from a single main gun hit, I thought some of the stuff from CMBN was both ridiculous and impossible, where PzGr39, which has a bursting charge actuated microseconds after impact, somehow didn't initiate as it flew through armor plate after armor plate without ever detonating. Now I grant there is a case where an 88 did this on a thinly protected US HT front to back, missing the engine and flying just above the transmission tunnel, I believe, and trashing the vehicle from one end to the other (have seen the pic from North Africa), the notion that this sort of plate pair penetration could happen through a whole row of halftracks seems fanciful and killing several Shermans with one shot outright ludicrous. Tip erosion should be very much an issue, as should differential loadings on the shell or penetrator, tipping and such. I recall the Russians did get a shocking to them through and through on a trophy King Tiger's turret face and rear using an 88 mmm L/71 at very close range. Not sure of projectile. I am absolutely prepared, though, given the gross overmatch of projectile with armor, to believe that the 120 KE on an M1A2 can get a through and through on a T-34/85, for in relative terms, it's armor is tissue paper.

Regards,

John Kettler

[Panzerpanic]

 

 

To kick the discussion back on its track. Here are glacis compositions for main Soviet medium and main battle tanks. Most of it is fairly common knowledge, but I never really found it amalgamated into one clear visual representation: 

 

 Do you have a legend for what the colors are supposed to represent?

Edited February 11, 2016 by Panzerpanic

[Vanir Ausf B]

Grey = rolled homogeneous steel

Yellow/gold = a fiberglass-like filler

White: air gap

The boxy shapes are various types of explosive reactive armor, I believe.

I'm not sure about the blue and green layers off the top of my head.

Edited February 11, 2016 by Vanir Ausf B

[Panzerpanic]

Grey = rolled homogeneous steel

Yellow/gold = a fiberglass-like filler

White: air gap

The boxy shapes are various types of explosive reactive armor, I believe.

I'm not sure about the blue and green layers off the top of my head.

Make sense! Thank you!

Edited February 11, 2016 by Panzerpanic

[BTR]

 Do you have a legend for what the colors are supposed to represent?

Ah yes, I forgot the main thing right :D?

• Grey: RHA
• Yellow (amber): Fiberglass (Glasstextolite) 
• Dark grey: RHA add on plates
• White: Air gaps
• Brown: ERA explosive component
• Blue: Ceramics
• Black: Rubber
• Yellow (chartreuse): Neutron lining

Edited February 11, 2016 by BTR

[Vanir Ausf B]

 

• Yellow (chartreuse): Neutron lining

This is perhaps meant to be an anti-radiation lining, not a layer of actual neutrons? While the latter probably would make very strong armor it would weigh many trillions of tons

[BTR]

Yeah, that was just a direct translation from Russian. It is anti-radiation lining. Apparently quite good against HEAT as well as Chechen campaign experience points out. 

Edited February 11, 2016 by BTR

[John Kettler]

It is indeed an anti-radiation liner, there to allow operations in a nuclear environment, specifically to allow the crews to survive if US/NATO used a neutron bomb which would otherwise kill the crews and leave the tanks functional. This is why the Russians went bananas over the neutron bomb, for it hit them where they lived and was a mortal threat to any attack. Here is a useful discussion of the liner and other goodies relating to Russian armor protection for tanks. I remember reading somewhere that the liner was made of boron loaded polyethylene, but YMMV on that.

http://www.tank-net.com/forums/index.php?showtopic=28647

Regards,

John Kettler

[BTR]

Quite an interesting piece on M829A3:

http://below-the-turret-ring.blogspot.de/2016/02/m829a3-apfsds-penetration-power-common.html?m=1

 

 

[Vanir Ausf B]

Interesting blog.

[Haiduk]

Ah yes, I forgot the main thing right :D?

• Grey: RHA
• Yellow (amber): Fiberglass (Glasstextolite) 
• Dark grey: RHA add on plates
• White: Air gaps
• Brown: ERA explosive component
• Blue: Ceramics
• Black: Rubber
• Yellow (chartreuse): Neutron lining

Black color is hard steel, not rubber. This is results of "Reflection" programm to increace protection level by mount a hard steel plate on glacis top. Last picture with T-72B3/T-90 is not accurate. Correct  is 5 mm rubber+3 mm of hard steel+19 mm air gap+3 mm of hard steel+5 mm rubber - in real this is NERA layer, which have protection capabilities on 40 % more, than homogeneous steel armor of equivalent thickness.   

Edited February 13, 2016 by Haiduk

[BTR]

Black color is hard steel, not rubber. This is results of "Reflection" programm to increace protection level by mount a hard steel plate on glacis top. 

As in, in point three?

[BTR]

Correct  is 5 mm rubber+3 mm of hard steel+19 mm air gap+3 mm of hard steel+5 mm rubber - in real this is NERA layer, which have protection capabilities on 40 % more, than homogeneous steel armor of equivalent thickness.   

Which is exactly as I have it :). 

[Haiduk]

Which is exactly as I have it :). 

In this case yes, though on the picture 3 mm hard steel plates signed as RHA. But black frontal 16/30 mm plates on T-64/T-72 this is 100 % plates of hard steel of "Reflection". Andrei Tarasenko wrote about this in own article about Soviet tank armor evolution: http://btvt.narod.ru/4/armor.htm

В ответ на это по завершении ОКР «Отражение» на танки вышеуказанных типов в ходе капитального ремонта на ремзаводах МО СССР на танках с 1984 года осуществлялось дополнительное усиление верхней лобовой детали. В частности на Т-72А устанавливалась дополнительная плита толщиной 16 мм, что обеспечивало эквивалентную стойкость 405 мм от ОБПС М111 при скорости предела кондиционного поражения 1428 м/с.

 

 

 

Edited February 13, 2016 by Haiduk

[BTR]

I'm not sure if I follow, but I don't make distinctions between different steel compositions. For example, T-80UD glacis includes a HHS plate in between ceramics of a much more durable composition than outer and inner shell, different glacis have varied strength steel (for instance early/late T-64's) and so on. That is not what the chart aimed to depict. I chose to separate the outer add-on steel plate for better visual reference. 

Edited February 13, 2016 by BTR

[HerrTom]

Sorry about the big image.  I can't seem to make it smaller.

 Thank you for the fantastic information, BTR!  Being an engineer, I naturally wanted to see what was going on, so I took an M829A3 penetrator and put it against the T-90's armour.  I wouldn't call this 100% gospel by any means, especially due to a couple of errors I made in the model and simplifications I made so it took less than 24 hours to run, but I think the from gist of it you can see that the penetrator at relatively close range against unangled armour pretty much cuts through it like butter.  The DU as a whole doesn't lose all that much energy as it passes through the armour.

So, given the following situation, I think it may be reasonable for a penetrator to go through and through, and possibly KO another tank:  M1A2 is within ~800 m of the target, and up against a 90 degree angle of armour.   It's a tanker's dream, I'm sure.  The only stipulation is that the rod may shatter upon reaching another tank since the steel tip is toast by now.

(Please ignore the radiation lining ruining everything at the end, I screwed up the material properties on it and broke the simulation at the end, exploding a lot of elements!)

[BTR]

Might want to twist that armor 68° though so it looks a little like this : 

Also M829A3 should shed around 100/90mm after coming in contact with the ERA explosive (brown) according to what we now know. It would be really interesting to see what happens in your simulation then. 

Edited February 14, 2016 by BTR