Krasnopol 152mm precision round vs M2 Bradley top armour

[Stagler]

A 122mm 2S1 round hitting intake grill on the engine deck of anything would destroy the engine. No questions asked, I don't care if its an M1 and M2 or a F'ing space chariot. The vehicle should be mission killed, the driver should be wounded, never mind the vehicle be able to drive away. Im sorry but I call BS on this one devs.

Edited July 4, 2015 by Stagler

[c3k]

The standard needed (I hate to say) is to proof that the in-game results are wrong.

 

I've looked at the Ft. Sill arty doc which showed 155mm arty near hits destroying tanks. (BTW, I agree that a bit more arty lethality vs. vehicles would be needed.) 

 

152/155 arty has much more penetrative and fragmentive effect than 120mm mortars.

 

We need to show real-world proof that a standard 120mm round will destroy a vehicle. (Point detonation, non-HEAT.)

 

It's a tough thing to argue. The kinetic model in-game is probably the best one outside of the secret code used in national laboratories. The HE model may need a little more work, especially with vehicle effects. IMO.

 

Ken

[Stagler]

Does anyone know if a 122mm artillery round has landed on the intake grill of an M2 before?

[Bydax]

 

We need to show real-world proof that a standard 120mm round will destroy a vehicle. (Point detonation, non-HEAT.)

Ken

Ukrainian T-64BV after a 120mm mortar round hit.

[c3k]

Bydax,

 

Thanks for the image...BUT...that's not helpful without corroborating evidence. Where did the 120mm hit? How do you know it was a 120mm round? What kind of 120mm round was it? Of the visible damage, how much was due to the (putative) 120mm round, how much due to post-impact fire? Was any caused by crew demolition; other weapons? Etc...

 

Remember, I'm actually trying to show that the damage model could to be tweaked. A bit more evidence is needed. (Yeah, I know what that sounds like...) The image just shows a damaged tank turret. (So would say a naysayer.)

[Stagler]

The metal intake grill would not stop the shell, it would partially penetrate the intake. The grill itself would not be able to hold the force of the shell or the blast.

[Muzzleflash1990]

I've wondered about the effects of non-direct hits. In my playing of CM I find artillery have almost no effect on vehicles unless a direct hit occurs. However, some couple of other sources, like this one page 10: suggest that 155mm rounds falling within 30m of tanks have a chance to rip of the tracks. It also offers examples of HE fragments from near hits going through armoured vehicles. I'm not sure what a near hit is, but is this result in CM to be expected:

 

http://postimg.org/image/4qev20fsl/full/

 

I would not have expected it to be out of commission, but there isn't a single dent on it. Not even the launcher, radar or tracks has gone from very green to geen-lightish damage.

 

Edited July 4, 2015 by Muzzleflash1990

[Bydax]

Where did the 120mm hit? 

Turret roof near the gunner's hatch.

How do you know it was a 120mm round? What kind of 120mm round was it?

 

Because ukrainian soldier who made this photo said so. And this is not that many options:

82mm - probably don't have enough force to deform the turret roof.

120mm 2B16/2S9 wasn't used in this area at that time.

122/152mm - will have different angle of impact.

So 2B11 120mm mortar with 3ОФ34(3,43 kg HE)/3ОФ36(3,16 kg HE) or 53-ОФ-843Б(1,4 kg HE) is most likely candidate.

Of the visible damage, how much was due to the (putative) 120mm round, how much due to post-impact fire? Was any caused by crew demolition; other weapons? 

 

AFAIK there was none "post-impact fire/crew demolition/other weapons". Crew rest nearby when tank was hit, they drive it to the rear but turret was "total loss".

Edited July 4, 2015 by Bydax

[cool breeze]

Well the 120mm DID immobilize the Bradley, so although the engine wasn't destroyed like we would expect the net result was similar...  not trying to defend the game particularly but the damage model for artillery seems in the right ballpark.  152/155 severely damages tanks and will destroy them with enough round in the area, while !20 mm severely damages IFVs and will destroy them with enough rounds in the area.  enough 120mm mortar will substantially damage tanks and maybe a lucky hit on a weak tank will destroy it.  152/155 easily destroys IFVs and can severely damage them with not many in the general area. 

I use something like IanL suggest and the result seem reasonable overall.   to destroy a tank I'll use 3 precision rounds of 155/152 and cross my fingers, or sometimes will use a short high intensity regular point fire mission.  killing abrams with the krasnopol is a little iffy so I might shoot 6 precision rounds or double up with 2 regular heavy point missions or whatever. against IFVs I'll send one 155/152 for an almost guaranteed out of action or quite a few more 120mm rounds for less expected result.  If I shoot 6 guided 120mm rounds at an IFV I expect it to be out of action.  6 120mm at a tank and I expect some system degradation.  The upside of shooting some extra rounds is sometimes you hit other guys in the area.  Oh and I shoot the short heavy non guided missions with the 120mm on the IFVs too like I do with tanks with 155/152.   

 

 

.....

 

Im starting to thing I might have myself a little confused here and be thinking more about the 122 howitzers.  not all the mortars are accurate enough to be that good at it, some of them can barely even hit building so I save 'em more for trees.  it seems like the American guided mortar rounds are similarly accurate or less to the 155 unguided.

Edited July 4, 2015 by cool breeze

[c3k]

 

Turret roof near the gunner's hatch.

Because ukrainian soldier who made this photo said so. And this is not that many options:

82mm - probably don't have enough force to deform the turret roof.

120mm 2B16/2S9 wasn't used in this area at that time.

122/152mm - will have different angle of impact.

So 2B11 120mm mortar with 3ОФ34(3,43 kg HE)/3ОФ36(3,16 kg HE) or 53-ОФ-843Б(1,4 kg HE) is most likely candidate.

 

AFAIK there was none "post-impact fire/crew demolition/other weapons". Crew rest nearby when tank was hit, they drive it to the rear but turret was "total loss".

 

 

Yeah, there is a suspicious "blemish" just on the gunner's side of the white stripe on the roof. It looks stepped... Is that it?

 

So, the tank was drivable? Were the weapons inop, or was the roof just damaged (and the commander's mg?)?  Etc.

 

Regardless, this is a data point. More would be nice. Like tests, etc., with specific rounds fired and damage.

[Kieme(ITA)]

Had some troubles with connection so I can't post again on the reply above, I did some extensive testing with the 152mm rounds, and they Always penetrated somewhere and destroyed the Bradley.

 

I'll try some more tests with 120mm mortars and 122 howz.

[Kieme(ITA)]

So, seems that 120mm mortars are coded so that they simply can't penetrate the top armor of a Bradley. Being this correct or not I don't know.

 

Anyway, here are some screenshots of tests:

 

 

 

The tests tend to go this way Always. Tracks being destroyed (probably by the nearby explosions) are a sure thing, then, sub system damage of various kind happens. Never scored a penetration.

Edited July 5, 2015 by Kieme(ITA)

[Kieme(ITA)]

122mm howitzer precision strikes.

The effect seems similar, no penetrations scored ever, although it's possible that the collateral damage to subsystems is a bit heavier.

 

 

Now, a screenshot that might have something more to tell: weakpoints.

As you can see there are 4 hit marks.

 

 

-number 1 = this one caused massive sub system damage, especially to the tows/targeting/ir optics/lsr warn and it appears to be very consistent, the hit is right there, the damage caused massive, although not capable of destroying the vehicle, and rightly so, because the damage was somehow absorbed by the large outside element which is the tow launcher.

 

-number 2 = right on top of driver's hatch. Now, I am not an expert and I don't know how much armor is there, but from an ignorant point of view maybe that should be some sort of a weakspot, or maybe not.

 

-number 3 = this shot resulted in a "hit weapon Mount". Ok, although it didn't destroy the main gun. Granted it's on the mantlet, but I wonder if such a shot might cause a serious trouble with the gun elevation system if not the gun itself. Another case where I would say: that should cause a destroyed gun.

 

-number 4 = like number 2. I don't know if the vehicle engine was destroyed by this shot, the Bradley was immobilized already by other nearby explosions (tracks hit), anyway, this is another example of potential entry point for a HE explosion that might (Always from an ignorant point of view) have some other effects on the inside of the vehicle (killing people).

[Stagler]

Number 4 is pretty much the same location where the rounds I fired hit. All in that salvo hit the top of the vehicle somewhere and hence the tracks were not damaged and it able to drive away. That hit would KO the engine no problem.

[MikeyD]

 

Considering the liberal use of aluminum in Bradley design...

 

Lets remember Bradley is clad in some very thick VERY expensive ceramic composite armor. So terribly expensive that they opted for something cheaper when designing Stryker. I vaguely recall armor steel equivalent for the bow was above 120mm (Tiger tank thickness). I discovered awhile ago that Krasnopol didn't have a HEAT cone at the end, it was just good old-fashioned HE. Bradley and Abrams - One game Krasnopol does nothing, the  next game its toast.

[John Kettler]

MikeyD,

 

Your # 40 is news to me!  Please post a link regarding the jaw dropping armor protection equivalent you just cited. Maybe my mid will be working my then. Right now it's shorted out. My understanding is the Stryker is fitted with ceramic armor tiles over the primary structure. 

 

Regards,

 

John Kettler

[Stagler]

Lets remember Bradley is clad in some very thick VERY expensive ceramic composite armor. So terribly expensive that they opted for something cheaper when designing Stryker. I vaguely recall armor steel equivalent for the bow was above 120mm (Tiger tank thickness). I discovered awhile ago that Krasnopol didn't have a HEAT cone at the end, it was just good old-fashioned HE. Bradley and Abrams - One game Krasnopol does nothing, the  next game its toast.

 

Over the engine intake? Really? Must be that VERY invisible ceramic composite armour.

 

Methinks the Bradley hit boxes need to be adjusted or altered.

[MikeyD]

Stryker is fitted with a version of Mexas armor tiles designed to handle a Russian 14.5 HMG fire at 50 meters, if memory serves. The equivalent of 52mm RHA armor. Actually, they had originally goofed on the specs and shipped the wrong thickness soft steel backing plates (14.5mm, coincidentally)! The manufacturer had to scramble to provide and additional 3mm plate to bring protection up to spec. Bradley uses a higher grade ceramic and much thicker soft steel backing plates. My info on equivalent armor thickness is off some long-forgotten website. It might've said 120mm equiv, it might've even said 150 equiv. Thick enough to stop Russian 30mm anyway. Thick Mexas tiles are also fitted to turret roof and troop compartment so they were thinking of offering protection against artillery too.

[Kieme(ITA)]

Thanks for sharing MikeyD,

after some tests I have seen that 152mm rounds have a very high percentage of kill against the Bradley (maybe there are cases when a 152mm didn't penetrate, but these seem to be the minority and they are out of my personal experience).

 

Ayway, what seems in discussion here is more like something regarding weakspots. Just like a tank might have a weakspot modeled (like in WW2 titles) or a partial armor not covered by ERA (T-72B3 front turret), we wonder if the Bradley top hull armor is modeled as a single thick slab of armor or if there are some parts with less to no armor. In particular I'm referring to the engine ventilation shaft and the driver's hatch. The first one seems especially fragile, maybe the covering mesh is capable of detonating the 120mm mortar/howitzer round, but given the speed of impact I would imagine a massive damage to the vehicle.

Another example of potential weakspot: how thick is the large hatch on top of the troops compartment? maybe it's well armored I just don't know (same for the driver's hatch). The only part I am pretty confident is the engine ventilation deck, as reported by Stagler, which really is a weakspot, because at least I know how internal combustion engines work and what kind of stuff is down there.

Edited July 9, 2015 by Kieme(ITA)

[BTR]

Point is, why are 9KG, 45KG, 600m/s rounds landing on compartments other than the troop compartments are not instant BBQ then? Also, 120mm RHA?

From www.tank-net.com.

Edited July 9, 2015 by BTR

[Kieme(ITA)]

Do those numbers (25mm) take into account the angle of the armor?

[BTR]

That in fact, is a very good question. I don't think this does (I am hoping it doesn't).

[Stagler]

Ayway, what seems in discussion here is more like something regarding weakspots. Just like a tank might have a weakspot modeled (like in WW2 titles) or a partial armor not covered by ERA (T-72B3 front turret), we wonder if the Bradley top hull armor is modeled as a single thick slab of armor or if there are some parts with less to no armor. In particular I'm referring to the engine ventilation shaft and the driver's hatch. The first one seems especially fragile, maybe the covering mesh is capable of detonating the 120mm mortar/howitzer round, but given the speed of impact I would imagine a massive damage to the vehicle.

Another example of potential weakspot: how thick is the large hatch on top of the troops compartment? maybe it's well armored I just don't know (same for the driver's hatch). The only part I am pretty confident is the engine ventilation deck, as reported by Stagler, which really is a weakspot, because at least I know how internal combustion engines work and what kind of stuff is down there.

 

Bingo.

[c3k]

Over the engine intake? Really? Must be that VERY invisible ceramic composite armour.

 

Methinks the Bradley hit boxes need to be adjusted or altered.

 

Yeah...it's looking like something may be a bit too robust.

 

HOWEVER... some real data to verify against the game behavior would be nice.

 

The hits on the engine slats would seem to be something that should at least cause engine failure. I'm not saying it's wrong, I'm saying it "seems" like it should. A large blast should propagate through the baffles. I don't know if the cover is just simple louvers or if there are more complex geometries behind the slats. (E.g., multiple slats... /\/\/\... in layers.) I don't know what type of HE the Brad was designed/tested to be proof against.

 

A video of mortar damage against a tank: http://www.bing.com/videos/search?q=120mm+mortar+vs+a+tank&qpvt=120mm+mortar+vs+a+tank&FORM=VDRE#view=detail&mid=3891FCA6C0BEB5F876353891FCA6C0BEB5F87635

 

Unfortunately, that's from Iwo Jima and the tank is an M4. There is NO information about the type of mortar. It could've been friendly fire or from the Japanese.

 

Simple HE is ineffective against tanks. (This does NOT mean that fragments are ineffective. I'm talking about bare HE laid on a tank.) Special anti-tank rounds have been developed for 120mm mortars. They contain seekers and HEAT warheads. Seekers, because you want to hit the top of the vehicle, not miss. But the warhead is changed because the standard warhead is not effective enough to assure a kill.

 

Therefore, standard 120mm mortar rounds, even if they hit, are lacking in their kill ability.

[Stagler]

Yeah...it's looking like something may be a bit too robust.

 

HOWEVER... some real data to verify against the game behavior would be nice.

 

The hits on the engine slats would seem to be something that should at least cause engine failure. I'm not saying it's wrong, I'm saying it "seems" like it should. A large blast should propagate through the baffles. I don't know if the cover is just simple louvers or if there are more complex geometries behind the slats. (E.g., multiple slats... /\/\/\... in layers.) I don't know what type of HE the Brad was designed/tested to be proof against.

 

A video of mortar damage against a tank: http://www.bing.com/videos/search?q=120mm+mortar+vs+a+tank&qpvt=120mm+mortar+vs+a+tank&FORM=VDRE#view=detail&mid=3891FCA6C0BEB5F876353891FCA6C0BEB5F87635

 

Unfortunately, that's from Iwo Jima and the tank is an M4. There is NO information about the type of mortar. It could've been friendly fire or from the Japanese.

 

Simple HE is ineffective against tanks. (This does NOT mean that fragments are ineffective. I'm talking about bare HE laid on a tank.) Special anti-tank rounds have been developed for 120mm mortars. They contain seekers and HEAT warheads. Seekers, because you want to hit the top of the vehicle, not miss. But the warhead is changed because the standard warhead is not effective enough to assure a kill.

 

Therefore, standard 120mm mortar rounds, even if they hit, are lacking in their kill ability.

 

It wasn't even a mortar that dropped the round in that screenshot that I took, it was a 2S1 122mm howitzer. I wasted about 8 minutes of fires time in that occasion, "foolishly" thinking a single laser guided top attack round with a very good chance to hit with one tube firing (from a crack crew and crack spotter team) would be sufficient to disable the M2. I had to then reorder the mission with all 3 tubes firing, then during the call the said M2 drove away to another hiding place. Which then proceeded to destroy a T-90AM piloted by the Russian blind-tank-driving championship crew. My point is basically that when survivability is over modelled, it has knock on effects for everything.

Edited July 9, 2015 by Stagler