Vehicles being hit with no penetration and crew reactions

[IICptMillerII]

The main AI issue I see in the original example of a Tunguska hammering an M1 is in WeGo play.  I would want the M1 crew to react and try to back out of the line of fire so as to reduce damage to optics, etc.  If playing realtime and I were controlling the US side, I'd pause and get my M1 the heck out of there asap.

 

This is a good point. Personally I have seen Abrams do just that, move out of the line of fire on their own to avoid losing external systems. In fact, I've noticed that Abrams tend to follow a NATO SOP from the later years of the cold war. The tankers were instructed to find and engage one target, firing once and then immediately backing up to reduce the possibility of being effectively engaged by the enemy. I have noticed my Abrams doing this in game, although I am not sure what the exact mechanics behind this behavior is (whether its an actual simulation of NATO SOP or just a generalized AI feature) However I do admit that when my Abrams have acted this way it has been due to enemy tanks and APCs such as the BMP-3 and not direct fire from a Tunguska. 

 

Seems like this could tie into a discussion/debate about the virtues of playing WEGO vs Real-time. One gives you finer control and micromanage while the other gives you the benefit of replays, better performance on large scenarios (at least for me) and what some argue is a more realistic way of how orders are issued and executed, orders are not instantaneous. 

[antaress73]

tac AI is much better but leave something to be desired in many situation. real-time sometimes let you correct the limited AI. 

[jspec]

I've been curious for a while about this idea in general, what would it feel like inside a modern tank that took a hit that didn't penetrate? From another tank let's say. 

 

Like a knock on the door? A little push? A car crash? I just don't have any concept as to what it would be like.  I wonder if any of our real-life tankers have heard stories they could share?

 

Edit - obviously hope they haven't been in a tank that got hit! Just meant stories they might have heard, or what they understand it would be like based on their knowledge.

Edited April 9, 2015 by jspec

[Apocal]

I've been curious for a while about this idea in general, what would it feel like inside a modern tank that took a hit that didn't penetrate? From another tank let's say. 

 

Like a knock on the door? A little push? A car crash? I just don't have any concept as to what it would be like.  I wonder if any of our real-life tankers have heard stories they could share?

 

Edit - obviously hope they haven't been in a tank that got hit! Just meant stories they might have heard, or what they understand it would be like based on their knowledge.

 

 

 

 

From what I understand, a lot of times you don't even feel or hear it over the sound of the tank operating normally. Or rather, as "normal" as can be expected in combat.

[agusto]

From what I understand, a lot of times you don't even feel or hear it over the sound of the tank operating normally. Or rather, as "normal" as can be expected in combat.

 

You can probably hear it - a large explosion like that of a HEAT round can be heard several 1000 meteres away, a few cm of steel wont stop the sound from travelling through it, especially given that metal in general doesnt dampen sound particularily well. On the other hand, as you said, the sound of the tank itself may be so loud that the impact of the round cant be heard. Anyways i cant but guess, someone more eduacted on the matter than me can hopefully ebnlighten us.

[John Kettler]

I have yet to receive any kind of definitive answer on crew effects of a DU penetration of an Abrams in which no crew member is in the direct path of the penetrator. What happens inside that tank? Numerous WW II accounts talk about abandoning the tank if hit and penetrated, based on the eminently reasonable presumption that the first penetration is likely to be followed by a fatal second one. Zaloga talks about the behavior of the poorly trained early war KV-1 crews. They were abandoning their tanks from nonpenetrating hits, some of which caused a small glowing spot in the inner face of the armor, or a wisp of singed interior paint. I believe there were also cases in which the rattle of 20 mm fire was enough to get them to bail out. Read about these incidents in his KV-1 & 2 Heavy Tanks 1939-45.  Unfortunately, the Google preview doesn't have the combat history part available now, though it was there a year or more ago when I last explored this matter.

 

I've already talked about the then-19 y.o. John Irwin, who had a whole two weeks of gunnery training before being assigned, straight out of the repple depple, to practically the lead tank in a 3 AD major offensive. His story is in the phenomenal Another River, Another Town. He turned out to be terrific, in both a 76 mm armed Sherman and one of three Super Pershings, but how many didn't?

 

Regards,

 

John Kettler

Edited April 10, 2015 by John Kettler

[Apocal]

I have yet to receive any kind of definitive answer on crew effects of a DU penetration of an Abrams in which no crew member is in the direct path of the penetrator. What happens inside that tank?

 

Hot burning hot dust and flaming shards of penetrator go flying all over, courtesy of DU's pyrophoric nature, igniting anything readily flammable and likely turning the tank's interior into a Viking funeral.

[Vergeltungswaffe]

So motivation is the most important factor when it comes to crew moral reactions when under fire?

Yes. Normal or lower motivation troops are much less likely to sit and slug it out, etc. They back up, bail out, and basically act like they don't want to die.

[Kieme(ITA)]

I indeed recently witnessed an M1A2, regular crew and normal motivation, being hit by a krizanthema volley, front turret hit (no penetration) + partial hull penetration, tracks destroyed, driver killed, the instant after that the three remaining crew panicked and abandoned the vehicle. 

[whitehot78]

 A tank that weigths 70 tons probably wont shake too much if it is hit by a several hundered kilogram projectile, even if it travels at supersonic speeds.

 

I don't agree with you .. A projectile weighing several hundreds kilograms, even if they were only, say, 200 -  and travelling at supersonic speeds will shake a 70 tons tank, and it would shake rather frantically..

[agusto]

I don't agree with you .. A projectile weighing several hundreds kilograms, even if they were only, say, 200 -  and travelling at supersonic speeds will shake a 70 tons tank, and it would shake rather frantically..

 

I hoped nobody would challenge me so i wont have to do the math . But lets see:

 

We have 70 ton tank (m1) that, for reasons of simplifaction, floats in a vacuum in space around earth (i know, i know ) and a a 200 kg KE penetrator (m2) that hits it at its center of mass with an impact angle of 90 degrees (more simplifactions...) at a speed of 1200 m/s (v2). The center of the coordinate system is located at the same point as the center of mass of the tank (=>v1=0m/s). Furthermore we assume that the collision is completely plastic. U is the energy that is transformed to heat and deformation upon impact, U = 0,5*(m1*m2)/(m1+m2)*(v1-v2)² and v' is velocity of the tank after the collision, v' = (m1*v1 + m2*v2)/(m1+m2). T is the amount of time in seconds during which the impact takes place. Given our input values,  v' = 3,41 m/s and U = 14,3 MJ. The energy used to accelerate the tank is 410 KJ. Given that the T << than 1 second, that in fact seems to be a mighty knock. In reality those 410 KJ that would accelerate the tank floating in space would have to be absorbed by the chassis and partially by the ground on which the tank is standing which would further decrease the amount of shaking the crew would feel, but actually i think they would have to notice at least something. The knock the crew would experience should approximately be compareable to a car hitting a wall at 20 to 25 km/h.

 

EDIT:

like in the video:

 

 

EDIT2:

source for the formulas i used:

 

http://de.wikipedia.org/wiki/Sto%C3%9F_%28Physik%29

Edited April 10, 2015 by agusto

[Vergeltungswaffe]

410 kj isn't even remotely a legitimate answer for a 200kg projectile moving at 1200m/s

 

Here's the stats for the WWII 8.8cm KwK 43 L/71:
Shell Weight: 10.40 kg
Muzzle Velocity: 1000 m/s
Kinetic Energy: 5200 kj

[Thewood1]

Where the hell did 200kg come from?  I doubt a loader could handle that shot plus the rest of the shell.

[Vergeltungswaffe]

Where the hell did 200kg come from?  I doubt a loader could handle that shot plus the rest of the shell.

 

Since a typical 8" naval shell weighs about 152kg, yeah, a 200kg shell would be a little tough to toss in the breech. 

[Kieme(ITA)]

Don't start blaming the metric system!

[antaress73]

A sabot weighs much less than that lol

[antaress73]

John kettler: looking at a mostly empty can of meat sauce according to real tankers that could stomach looking inside a sabot destroyed Iraqi tank that didnt explode.

Edited April 10, 2015 by antaress73

[HerrTom]

So, in terms of pure kinetic energy, a monstrous 200kg shell travelling at 1.2 km/s has an energy of 144 megajoules.  That's just (1/2 m u²).  According to Wikipedia, the M829 shell weighs 18.64 kilograms, and has a muzle velocity of 1,670 m/s.  That gives a muzzle energy of 25.74 megajoules. 
If all of that energy is released from the impact, being hit by an M829 at point blank is like having 5 kilograms of TNT go off on the outside of your tank.  That may be hard to miss.  I read that Chobham armour is typically about 5cm thick, which means that the reaction force from the shell decelerating in that thickness is 5.1 giganewtons, which would give a nice jolt, even if it's only applied for a tiny fraction of a second.

 

Anyway, I'm not sure what this all means in terms of a chunk of metal hitting another big chunk of metal/ceramics/composites or whatever.  But those are the numbers.  I do know for sure that I'd rather not be in a tank that's shot by one of these in really any circumstances!

[antaress73]

As far as we know, no m1s with live tankers inside were ever hit by a real powerful sabot (iraqis training rounds do not count and even then they were so innacurate that the sample is minimal). I would imagine the noise is deafening (claaaaanggg) thats why they wear helmets and ear protection )

[John Kettler]

Apocal,

 

Your answer is what I'd expect based on imagery I've seen of what happens when DU penetrates armor, but that doesn't seem to be at all the picture painted by panzersaurkrautwerfer. Further, I have zero info on what the automatic fire suppression system on an Abrams can do vs DU penetration effects of heat and pressure spiking. I know the system can quite effectively strangle at least earlier RPG penetration effects, practically before they've begun. 

 

agusto,

 

In which universe, please, does even an M829A4 LRP--by itself-- weigh 200 kg? Remember, M1 ammo is fixed, so you're talking penetrator, sabot, propellant, semi combustible case and stub. The M829 Wiki lists the actual penetrator weight for the M829A3 as 10 kg, and the total round weight as 22.3 kg. MV is 1555 m/sec. By way of comparison projectile weight alone for US 203 mm AP Shell was 152 kg. Please run the corrected numbers. 

 

Regards,

 

John Kettler

[Thewood1]

I thought between GW1 and GW2, a couple M1s had been hit by friendly M1s.

[agusto]

Where the hell did 200kg come from?  I doubt a loader could handle that shot plus the rest of the shell.

 

whitehot78 suggested 200kg. Give me a better value and i will do the calculation again later.

 

In which universe, please, does even an M829A4 LRP--by itself-- weigh 200 kg? Remember, M1 ammo is fixed, so you're talking penetrator, sabot, propellant, semi combustible case and stub. The M829 Wiki lists the actual penetrator weight for the M829A3 as 10 kg, and the total round weight as 22.3 kg. MV is 1555 m/sec. By way of comparison projectile weight alone for US 203 mm AP Shell was 152 kg. Please run the corrected numbers. 

 

I will do the calculation again with realistic numbers later. The above was more supposed to be a educated guess rather than an actual mathematical representation of physical reality. Note that i mentioned twice that it is a simplified situation, btw. I didnt want to do a complete mathematical model, i just wanted a to get a quick idea of the magnitudes we talking about here.

 

410 kj isn't even remotely a legitimate answer for a 200kg projectile moving at 1200m/s

 

Here's the stats for the WWII 8.8cm KwK 43 L/71:

Shell Weight: 10.40 kg

Muzzle Velocity: 1000 m/s

Kinetic Energy: 5200 kj

 

Actually you did not understand my post correctly. 410kj is just the energy that in a zero-g environment would be translated into motion. The rest would transfered into heat and deformation. Note though that we are speaking of a simplified situation here. IRL such values may vary, depending on the materials used.

Edited April 10, 2015 by agusto

[panzersaurkrautwerfer]

 

 

Hot burning hot dust and flaming shards of penetrator go flying all over, courtesy of DU's pyrophoric nature, igniting anything readily flammable and likely turning the tank's interior into a Viking funeral

 

There are flaming bits and the like.  It's not always a catastrophic tank ending explosion.  Odds of crew survival are not good to put it mildly, but even some Soviet type tanks that are prone to explosions failed to cook off in the 1991 and 2003 fighting despite being struck with a sabot.  An Abrams with a decent fire suppression system, and lacking stuff that'll still burn after a halon dump might not be as entirely destroyed.  

 

In terms of impacts, I thankfully never got hit myself, but things like RPGs and non-penetrating KE strikes certainly made a racket, and MG fire was at least somewhat audible from conversations I can recall.  On the other hand if none if it is coming through it's hard to judge how bad it might be, it could be the optic has been jarred a bit and needs to be reset, or the whole assembly could have been simply sheered off somehow.  In terms of reasonable effects, something similar to the laser warning backup is about right.  Generally not getting hit, even by non-penetrating strikes is a state the tanker prefers to be in.  So unless I've got a good reason to sit still and take some hits, I'm going to pop into reverse and get behind cover (and try to find the guy messing up my paint job, so I can smoke him).

[agusto]

So, in terms of pure kinetic energy, a monstrous 200kg shell travelling at 1.2 km/s has an energy of 144 megajoules.  That's just (1/2 m u²). 

 

Thanks. Looks like i missed a 0 there.

 

 

If all of that energy is released from the impact, being hit by an M829 at point blank is like having 5 kilograms of TNT go off on the outside of your tank.  That may be hard to miss.  I read that Chobham armour is typically about 5cm thick, which means that the reaction force from the shell decelerating in that thickness is 5.1 giganewtons, which would give a nice jolt, even if it's only applied for a tiny fraction of a second.

 

Yeah, you would certainly feel something.

 

 

John kettler: looking at a mostly empty can of meat sauce according to real tankers that could stomach looking inside a sabot destroyed Iraqi tank that didnt explode.

 

"Uncle Saddam's Mashed Tank Crews - Now with awesome new flavour: Delpleted Uranium"

Edited April 10, 2015 by agusto

[IICptMillerII]

I thought between GW1 and GW2, a couple M1s had been hit by friendly M1s.

This is true. I believe that there were two friendly fire incidents with American tanks in the First Gulf war. Both times the Abrams was hit in the rear and the shell penetrated. I believe but could be wrong that in one of the incidents one of the crewmen was killed or wounded, possibly the driver of the tank. If anyone knows more about the incidents feel free to add/correct me. 

 

As for feeling a jolt when being hit, I think that it would be more of a vibration, and a quick one at that. Remember that it is a small object hitting at a very specific point. A lineman in football (American football) running at full speed and tackling you has roughtly the same amount of force as a point blank 12 gauge shotgun blast to the chest (based on the players specific weight and speed at impact. It varies, but it is possible to have this amount of force) The reason the football player doesn't turn the person he is tackling into putty is because the force is spread out over a much larger area. Thanks to Newton we know that an object being struck by a bullet can only be moved as much as the recoil imparted on the rifle moves the rifle. Thats why when you see people flying around from bullet hits in movies its completely unrealistic. What this means for tanks is that an enemy tank being hit by a Sabot round can only be moved as much as the gun firing the Sabot round recoils. (Yes, the gun does recoil more but is dampened a lot by mechanisms in the tank) Considering the amount of kinetic energy the Sabot round has is less than when it first left the muzzle of the tank gun, and that the target tank weighs many tons (anywhere from 45-70 depending on the tank) the actual 'jolt' felt by the tank should be rather minimal.

 

That said I still think that the crew would know it was hit, as I think that a non-penetrating round would cause some kind of vibration. That along with the sound of the impact (dampened by the tank itself as well as the hearing protection of the crew) would let those inside the tank know that they had been hit but the round hadn't penetrated. 

 

Bringing this back to the original question asked in this thread, none of this would be enough to stun a crew into combat ineffectiveness. The only way the crew would be made combat ineffective is if it was penetrated.