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Roo5ter

A Quick Look at Bomb Effectiveness vs Armor

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Let's start off the conversation with this 18 second clip from April 2015:

500kg bomb, accurate drop and the T34 does not care.

 

Video taken today:

T34 once again in crater from an accurate drop of a 500kg bomb and no visible effects on target.  Just for reference the smoke coming out the back of the tank goes away and it drives on as normal (since I didnt record long enough).  In the early part of the video before dropping the bomb the other tanks spewed some good ol diesel exhaust out as well.

 50r4E2X.png

 

I was pretty surprised to see that armor is still shrugging off such large munitions after not flying for a year and a half.  Since I could not even come close to hoping to have the knowledge of the community or know which resources are the best and most accurate to find this information, is there proof that this is realistic or is there proof that the damage modeling should be changed?  I would suspect that even if the tank was largely intact the crew would doing less than swell or dead and some tanks possibly be flipped onto their sides.

Edited by Roo5ter

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It looks like you're off in the drop by about 10 - 30 m. I've found that with tanks, I need to have the bomb set off basically right under them.

 

Can't comment on historicalness, so I'll leave that to someone else.

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I wouldn't have expected an instant kill on the 2nd one, but I don't see how a T34 with 1100 pounds of explosives going off about 3 tank lengths or 20 meters away is would not affected the tank or more likely the crew.  Some googling found me nothing that I feel is super trustworthy on the effects.  Even 250kg in game right now need to be very close to the tank to disable.  That's a pretty big bang.

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Tanks are extremely ressilient to blast damage and are very hard to kill through an indirect hit with HE weapons, even heavy bombs.

 

It seems illogical, that a tank and its crew would survive the blast from a 500kg bomb at a distance of just 10m or so, but it really will often do exactly that.

 

The human body is surprisingly resistant to shockwaves like those produced by an explosion. The greatest threat comes in the form of shrapnel or getting trapped in a collapsed building (houses on the other hand are lousy at surviving a blast). Provided he isn't hit by shrapnel or debris a person can survive a blast that will completely flatten a wooden building and escape with a pair of ruptured eardrums.

 

A human inside a tank is completely protected from shrapnel and from most of the shockwave as well. And the tank itself is not easily damaged by high explosive either, unless it's a direct hit (which can cause spalling that can damage vital systems and kill crew)

 

Don't believe me? Take a look at this: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA329188

 

It's a report done by the Army Research Lab in 1997 about the lethality of HE-bombs. It's an interesting read by itself, but the thing you want to look are the charts on p. 31 and 32. It's "kill probability" charts depicting the probability of a vehicle being "killed" (either disabled or crew incapacitated) by different types of HE weapons, the heaviest being a 1000lbs air dropped bomb.

 

The last of the charts show the effect of the HE blast on a tank, and you'll notice, that even for the 1000lbs bomb the "kill probability" drops to zero at a distance of just 18 feet (just under 6m), meaning that if a 1000lbs bomb goes off just 6m from a tank, there is essentially NO chance of killing the crew or disabling the tank (though the crew will probably be deafened)

 

Ok, so this report is from 1997, surely a tank from '97 is way tougher than a tank from '42? Sure, but take a look at the chart above: That's the kill probability of the same bombs against a soft target, a truck. Here the kill probability of the 1000lbs bomb falls to zero at just 47 feet distance (around 15m). Miss a soft target like a truck by just 15m with a 1000lbs HE bomb, and there is pretty much no chance of disabling it. It's safe to assume, that the survivability of a WW2 tank lies somewhere between a 1997 tank and a truck, probably closer to the first. That means that if you miss a T-34 with a 500kg bomb by something like 10m, there is pretty much no chance at all to kill it.

 

Seems crazy, right? I thought so too, but apparently HE weapons are just not that good at killing tanks or even unarmoured troops. They are however great at getting buildings to collapse.

Edited by Finkeren
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Yep. I don't know, if it is modelled in the game, but IRL it is much more effective with zero delay, so the bomb explodes, when hitting the ground, not after ramming into it.

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The human body is surprisingly resistant to shockwaves like those produced by an explosion. The greatest threat comes in the form of shrapnel or getting trapped in a collapsed building (houses on the other hand are lousy at surviving a blast). Provided he isn't hit by shrapnel or debris a person can survive a blast that will completely flatten a wooden building and escape with a pair of ruptured eardrums.

 

A human inside a tank is completely protected from shrapnel and from most of the shockwave as well. And the tank itself is not easily damaged by high explosive either, unless it's a direct hit (which can cause spalling that can damage vital systems and kill crew)

 

Don't believe me? Take a look at this: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA329188

 

It's a report done by the Army Research Lab in 1997 about the lethality of HE-bombs. It's an interesting read by itself, but the thing you want to look are the charts on p. 31 and 32. It's "kill probability" charts depicting the probability of a vehicle being "killed" (either disabled or crew incapacitated) by different types of HE weapons, the heaviest being a 1000lbs air dropped bomb.

 

The last of the charts show the effect of the HE blast on a tank, and you'll notice, that even for the 1000lbs bomb the "kill probability" drops to zero at a distance of just 18 feet (just under 6m), meaning that if a 1000lbs bomb goes off just 6m from a tank, there is essentially NO chance of killing the crew or disabling the tank (though the crew will probably be deafened)

 

Seems crazy, right? I thought so too, but apparently HE weapons are just not that good at killing tanks or even unarmoured troops. They are however great at getting buildings to collapse.

So I cut out a few things in here just for the sake of brevity.  You brought up a lot of points and I think some are really good and some I can definitely argue against.

 

Humans are not resilient to shockwaves.  It is actually scarily horrible how poorly they fare from shockwaves and I am speaking from experience here.  You can literally get loopy or hospitalized from firing too many SMAW rockets in one day.  I did find someone quoting data that showed the tanks surviving blast but animals inside dying.  They didn't quote the data so I will have to search for that and see if that has any sort of validation because it could really go either way.  I would think that a tank crew would have their bell rung horribly so at the very least.  CDC has a  report that goes into detail on effects of structures and human bodies.  I am going to have to read this -  https://www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-125/125-ExplosionsandRefugeChambers.pdf

The report you linked is good stuff, I am going to have to look over it in more detail.  Trucks I wouldnt expect to be destroyed super easily by a bomb.  Military trucks are pretty resilient it is the stuff that is thrown that would tear into it causing damage.  I don't see where it defines a kill for the truck though.  The truck is a good basis since we know a 1997 truck isnt going to succumb quicker to a bomb than a 194x tank.  there are a lot of things that can be damaged on a truck in a blast that render it inoperable but not a catastrophic kill.  It is possible the truck takes quite a bit of damage but is far from destroyed.  You can see this in action vs the aircraft which are much more reliant upon their structure than a ground vehicle.  Those are some pretty nasty numbers vs the aircraft and this also ties into human discussion.  You can't expect a human to survive what an aircraft cannot.  Look at figure 13 and see how the aircraft aluminum fared vs an 8 lb charge at 7 feet.  That 'tiny' explosion would wreck a human.  Of course we are throwing more variables into the equation as we both noted by encasing the humans in steel.

 

I did look at the tank kill chart and thats pretty interesting and about as damning as evidence there is that the tank will be ok.  I just can't find in this report where they define what Kill probability is.  I see your definition as disabled or crew incapacitated but when i search the document for crew or human or kill probability I am not seeing that definition which is a big issue.

 

War for the infantrymen is often referred to as an 'HE race.'  HE weapons are certainly not the best at killing hardened vehicles or tanks which is the discussion point of this post but they are absolutely fantastic at killing unarmoured troops.  The kill radius for a 40mm M203 HEDP round is 5 meters and the casualty is 15 (consider there is a small amount of shrapnel thrown).  Those are the ranges when the probability of kill/casualty is at 50%.  The total weight of the grenade is about 8 oz to put that into perspective.  So we are talking about a bomb that has somewhere around 1,000 times more charge which equates to - something more than 5 meters kill 15 casualty :).  

 

Quick google and I can see people are pulling some numbers out of their asses when it comes to the blast radius for large bombs.  Will have to look into that more as well and equates to the open crewed weapons like AT and AA guns just out of curiosity.  Going to look into a few things a bit more, but I think in the meantime I should try getting some near hits with contact fuse bombs since to see if it appears to be modeled differently than bombs we bury.  Not sure how far a contact fused bomb would actually penetrate the surface before detonating.  Should report back on that tomorrow sometime.

 

Edited by Roo5ter

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I'm not gonna argue the point about unprotected human's ressilience to shockwaves. It contradicts a couple things I've read, but obviously, I don't speak from experience and I'm not going to dig up quotes, because after all this is about how armour fares against HE, and this is where I feel a bit more secure in my argument.

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If you gave me a choice between taking a huge blast in a T-34/85 or something like an MTV truck or an MRAP I'd pick the T-34/85 every time.  Not only is it an actual tank and not a crappy infantry wagon, but even though the T-34 is ancient the greatest favor it does for you after protecting you from penetration is it's far, far greater mass protecting you from the shockwave.

 

I wasn't a tanker, but had plenty of occasion to chat with them and they could take some really gargantuan hits and keep functioning thanks to their tanks and human resilience.  Of course, we aren't talking about TBIs(Traumatic Brain Injuries) that kill you down the road but nobody cares about that at the time.

 

Anyhoo, if you want to kill tanks with the stuka, bring the leg cannons with AP or make sure you can hit the vehicle almost directly with your bombs.

Edited by Silas
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If you gave me a choice between taking a huge blast in a T-34/85 or something like an MTV truck or an MRAP I'd pick the T-34/85 every time. Not only is it an actual tank and not a crappy infantry wagon, but even though the T-34 is ancient the greatest favor it does for you after protecting you from penetration is it's far, far greater mass protecting you from the shockwave.

This would be my line of thinking as well. The sheer mass of the tank itself should be a form of protection in itself from the shockwave, not least because unlike a lighter vehicle, a tank isn't gonna be thrown around by the blast.

 

However, common sense it not much use when discussing topics like this. Few of us have much hands-on experience with high explosives in any quantity, so our common sense will mostly be influenced by stuff we've seen on TV. I learned that the hard way, because just like the OP, I thought it was "obvious" that the DM of tanks was way off, when this was discussed back in early alpha. I mean, how could tank and crew possibly survive such a blast right next to it? But when I started seeking out actual studies and found reports like the one I linked to, it turned out that my common sense was worthless.

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Somewhere long ago there were posted by Dev's the damage radius of various bombs

 

I do have some RL personal experience of HE blast and shockwave damage,  (over 400T of different types ordnance involved) all I will say is that with small amount of protection (less than a tank) the difference of being in the open is huge, and I am still here

 

Cheers Dakpilot

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But that bomb sat directly under the tank.

Well, A Bomb hitting the Ground with Delay Fuse will Dig in a Good Way on Soft Surface. That Directly Reduces it's effectiveness. 

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Well, A Bomb hitting the Ground with Delay Fuse will Dig in a Good Way on Soft Surface. That Directly Reduces it's effectiveness. 

 

 

In the IL-2 with two 100kg bombs set to explode on impact I usually(always?) destroy the tank if I strike it directly.  The same for two rockets(132s and the medium ones I can't recall the name of) .  It's possible setting a delay has an effect in the sim, since the bombs do visually dig into the ground.

Edited by Silas

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In the IL-2 with two 100kg bombs set to explode on impact I usually(always?) destroy the tank if I strike it directly.  The same for two rockets(132s and the medium ones I can't recall the name of) .  It's possible setting a delay has an effect in the sim, since the bombs do visually dig into the ground.

German Tanks have thinner, flat armor on most parts of their tracked armored vehicles. That Traps the Bomb Blast far more effective than the Sloped Armor on the T-34 and the thick KV-1 Armor. 

Just by their designs the Russian Medium and Heavy Tracked Vehicles (the T-34 is not a tank) are better at deflecting Explosions. 

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Here is something from "Terminal ballistic data, Volume III"

Crater.jpg?ver=0

 

If I'm not mistaken, the 500kg bomb would create about 16 meters wide and 5 meters deep crater covered with loose material. I think that the T-34 would not be able to get out of this.

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The description says this test was done with SC50 and SC500 bombs. Notice the shock wave.

https://www.youtube.com/watch?v=kLCVqOl0Qtk

 

German Tanks have thinner, flat armor on most parts of their tracked armored vehicles. That Traps the Bomb Blast far more effective than the Sloped Armor on the T-34 and the thick KV-1 Armor. 

Just by their designs the Russian Medium and Heavy Tracked Vehicles (the T-34 is not a tank) are better at deflecting Explosions. 

Depends, their armour was of worse quality and gaps between armoured plates were not uncommon for russian tanks. This would render the crew & equipment helpless against shock waves.

Edited by 6./ZG26_5tuka

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Do not forget that tanks have systems outside the protective armor shell - mostly the running gear and the tracks. For example after the german breakthrough at Sedan in 1940 Stukas immobilized a score of french tanks before they could concentrate for an attack simply by damaging their running gear. Similarly tanks often bogged down in bomb craters (the picture Klaus Mann posted shows this). I also thought that tanks were a bit too resilient against bomb damage, but maybe the delay setting really does make the difference (I have it on a second for security reasons). I'll try a no delay setting.

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IL-2 Sturmovik: 1946
v.4.11 manual:

 

Bomb fuzes

Bomb fuze feature is made in such a way that if the new "Bomb Fuzes" difficulty option is
turned off, bombs behave like in 4.09 (zero arming time). When diff. option is on, the arming
UI has extra fuze type selection box and available detonation delay values are limited to the
values available for the selected fuze.
Several historic fuzes are modelled and bombs now store a list of different fuzes that they can
use. Complexity is hidden from the user by grouping the fuzes to few different groups so user
doesn't need to learn several dozen of fuze names. Availability of fuzes even change by
mission date. User only needs to select type of the fuze needed for the bombing task he is
going to perform.

Instant

Required longer arming time/distance, but allows instant detonation (no long delays) or very
very short delay of 0.1-0.5 seconds. Typical fuze for med/high-alt level bombing.

 

Low level

These fuzes are armed very quickly but the safety comes from delay. Usually doesn't allow
delays below 4 seconds or so. Like the name says, these fuzes are suitable for low level
attacks, but don't allow instant detonation for pilot's safety.

 

Delay

Generic fuzes that allow longer delays and have medium arming times. Something between
types 1 & 2.

 

Long delay

Fuzes that allow very long delays like 90 seconds etc.
When player selects a loadout which has bomb, the fuze type selection box is populated with
the fuze types that are available for the selected bombs. Not all bombs have all different types
available. When the fuze selection is made, the fuze detonation delay selection box is
populated with the available values that the fuze supports. The actual fuze selection is made
automatically when the mission starts or user spawns in dogfight mission.
German electric fuzes are exception to this. These fuzes do not provide delay selection at all.
Fuze has three different modes that can be changed during flight. This requires a new mapping
at the controls menu. Available modes are "instant", "short delay" and "long delay".
Detonation delay & arming time depend of the actual fuze type that is selected automatically.
Electric fuze circuits work so that if the fuze fails to arm on instant or short delay mode, it
automatically reverts to long delay mode which needs lower arming time.

...

 

4.11 introduces some changes to the bomb's penetrating effect which is related to the
detonation delay. Bomb with instant detonation (zero delay) doesn't penetrate into ground or
into target that it might hit and therefore its explosion is little different than if it would dig into
ground/house/ship. Bomb digging into ground before exploding has slightly reduced "daisy
cutter" effect, so its power against ground units is slightly reduced. In general you want to
attack ground troops with zero delay or drop the bomb in so shallow angle that it doesn't dig
into ground. Against houses and ships the penetration is desired effect. Bomb explosion makes
more damage to confined space when it explodes inside it. Small bomb dropped on roof of a
house might do only superficial damage to the roof if it explodes immediately and house it not
destroyed. If the same bomb would penetrate the roof and explode inside the house,
destruction is much more probable.

 

 

I did not check wether this is already implemented in BOS, but I think it should be.

Additional loadout options like high explosive blast SD bombs, AB dispersers and f.g. Ptabs and napalm would be great.

Edited by [DBS]El_Marta

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I have just tried a bunch of bombs vs the soviet tanks in QMB. I used Bf 109 E-7 and Ju 87 D-3 with SC50, SD70, SC250 and SC500 and I have found it doesn't make a difference whether one has the fuses set to contact or 1sec delay - unless you hit directly the tanks will continue on without showing any signs of being damaged.

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This would be my line of thinking as well. The sheer mass of the tank itself should be a form of protection in itself from the shockwave, not least because unlike a lighter vehicle, a tank isn't gonna be thrown around by the blast.

 

However, common sense it not much use when discussing topics like this. Few of us have much hands-on experience with high explosives in any quantity, so our common sense will mostly be influenced by stuff we've seen on TV. I learned that the hard way, because just like the OP, I thought it was "obvious" that the DM of tanks was way off, when this was discussed back in early alpha. I mean, how could tank and crew possibly survive such a blast right next to it? But when I started seeking out actual studies and found reports like the one I linked to, it turned out that my common sense was worthless.

I think the biggest difference between the tank and the infantry vehicles is not the mass but the fact they are much better sealed.

 

I didn't think it was obvious that the DM of the tanks was way off which is why I finished my post with the question whether this was realistic or not.  There's definitely beens oem good discussion here.  Plus we got to see a light tank go flying, and that was hilarious.

 

Also pretty confused how this ended up being sent to 'technical issues and bug reports.'  Not sure if someone just wanted to bury the conversation or what.  This is a discussion about damage modeling and realism not whether the system is working on a technical aspect or bugged.  Also huge thanks for the moderator that moved it not saying... hey i moved it for whatever reason...

I have just tried a bunch of bombs vs the soviet tanks in QMB. I used Bf 109 E-7 and Ju 87 D-3 with SC50, SD70, SC250 and SC500 and I have found it doesn't make a difference whether one has the fuses set to contact or 1sec delay - unless you hit directly the tanks will continue on without showing any signs of being damaged.

 

Sounds good, I'll try to snag a video.  Im sure the accuracy needed for this will end the life of my Stuka many times over.

Edited by Roo5ter

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But generally it seems bombs are not as effective at killing tanks as the super graphics might suggest . I have little trouble in the stuka with the anti tank guns to get close and kill a tank.

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Guest deleted@103832

I'm just gonna throw this out here; happened 20 min ago on the TAW server. I'm not going to venture an opinion as to whether this 500kg bomb should have taken out a tank, but I find it odd that the game allows bomb skip, but in this case not only was an air burst not modeled - instead placing the explosion at ground level, it did not even put the burst at the actual location of the bomb. 

 

https://www.youtube.com/watch?v=jD-2MIPJx40&feature=youtu.be

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I'm just gonna throw this out here; happened 20 min ago on the TAW server. I'm not going to venture an opinion as to whether this 500kg bomb should have taken out a tank, but I find it odd that the game allows bomb skip, but in this case not only was an air burst not modeled - instead placing the explosion at ground level, it did not even put the burst at the actual location of the bomb. 

 

Well that was pretty interesting.  I tried to blow up some t34s today with contact fuzes but after about 15 tries and continually getting BT7, T70 and KV1's I said it will have to wait til tomorrow for another go.  I did note the BT7's are a bit easier to destroy with the bombs when less accurate and the KV1's are more difficult, as we would expect.

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but in this case not only was an air burst not modeled - instead placing the explosion at ground level, it did not even put the burst at the actual location of the bomb

What? It seems to me the game did exactly these things: The bomb exploded in the air between the two tanks. But it's hard to judge on a 2d image, you should rotate the camera around the bomb while it's exploding, that would give a better idea of where it's taking place exactly.

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Guest deleted@103832

I took a relook - from the bomb perspective it does in fact explode in place, but from the ground perspective, it appears to disappear momentarily, move back 10m, and explode from ground level. I don't know what to make of it, it could be a playback issue. 

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I really dont know about the effect a bomb can cause in a crew with the distance. But threre are some reports about german heavy tanks destroyed with He 152 shells without pierce the armor.

Only the blast were enought to cause damage inside. I know is a direct hit but a 152 shells has a lot less explosive power than any bomb.

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It is hard to say lung damage or lung collapse occurs at about 15 psi and a 500 lb bomb will produce a incident pressure of (448 Kpa)  65 PSI at 30 meters or approx 100 feet.

 

at 5 meters(16 ft) the incident pressure goes up to (2036 Kpa) 295 PSI

 

(448 Kpa) 65 PSI is usually fatal.

 

Reflected pressure would be (13952 Kpa) or 1971 PSI at 5 meters (16 ft) Now that is a mean shockwave when it hits your tank.

 

I would not want to be in the tank to test what that amount of pressure does to the human body or the tank

even if it just last a few milliseconds..


A rugged Russian tank crew could walk out of all of those damaged buildings

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