[CORRECT AS IS]CBU-87 bomblets are not armor-piercing

[Auranis]

So, like many other DCS World players I have noticed how ineffective the CBU-87 seems to be against armor. You can drop several canisters on a tank column without getting a single tank kill.

 

Well, tonight I was digging through the weapons lua files, and I think I found the problem here in Scripts/Database/Weapons/cluster_data.lua:

 

BLU97B_DATA =

{

scheme =

{

cluster =

{

mass = 1.540000,

caliber = 0.063000,

cx_coeff = {1.000000, 0.390000, 0.380000, 0.236000, 1.310000},

L = 1.68000,

 

model_name = "PTAB-2_5KO",

},

 

warhead = simple_warhead(2.0),

},

 

name = _("BLU-97B"),

type_name = _("cluster"),

}

 

simple_warhead() is a function that, in a nutshell, returns a frag bomb definition of a given power. The above code seems to model the BLU-97B bomblet as being a frag bomb without any armor piercing effect.

 

I suspect simple_warhead() was used by mistake when cumulative_warhead() was intended to be used. In any case, I hope it is a simple fix to get the CBU-87 back to its tank-killing mission :)

[cthulhu68]

, I hope it is a simple fix to get the CBU-87 back to its tank-killing mission :)

CBU-87 is anti-personnel/anti-armor, not anti-tank.

[Auranis]

My point still stands, the CBU-87 is not *modeled* as being anti-armor in the game... and besides, what is the difference if the munition can defeat the top armor of most MBTs?

[BIGNEWY]

Hi

 

CBU-87 is for soft targets

 

CBU-97 would be better for tanks

 

thanks

[stormrider]

CBU-87 is anti-personnel/anti-armor, not anti-tank.

Wait what?

[Frederf]

You want to try that one again, chief?

[Emmy]

If it will bleed or burn - CBU-87

If it will burst or melt - CBU-97

[PhantomCat]

2 min google search would tell you CBU-87 is anti-personnel

[Frederf]

>200mm RHA

[ChickenSim]

The BLU-97B is pretty similar to the Mk118 bomblet used in the Mk20/CBU-99, with the exception that the Mk118 is supposed to penetrate soft overhead cover a little better.

 

Both use shaped charges (standoff methods differ), both provide secondary fragmentation effects, and are roughly the same size and weight. BLU-97s are actually a little wider and heavier, but they do have a scored steel fragmentation jacket (much like an anti-armor Hellfire does, to increase flexibility).

 

Mk118s are considered anti-tank bomblets that also happen to be effective on soft area targets like personnel. They even get a special warhead profile in DCS.

 

warheads["MK118"] = -- Mk-20

{

mass = 0.59,

expl_mass = 0.25,

other_factors = { 1.0, 1.0, 1.0 },

concrete_factors = { 1.0, 1.0, 1.0 },

concrete_obj_factor = 0.0,

obj_factors = { 1.0, 1.0 },

cumulative_factor= 10.0,

cumulative_thickness = 0.25

 

I'm not seeing a real justification that the CBU-87s shouldn't get the benefit of their shaped charges, but Mk20s do, just because CBU-97s are better at killing tanks.

[function129]

PhantomCat, that is a very incorrect assertion. If you have no experience with the weapon and do not know where to look for the data, you should hold your assessment before stating something false and demeaning towards a dude who’s trying to fix and improve your weapons capabilities in game.

 

They do have anti armor capabilities, and it is correct for one to assert that a bomblet functioning above a tank will render the tank very dead by punching a hole in the top of the turret, and filling it with fire, disabling the engine, etc.

 

Source: https://www.globalsecurity.org/military/systems/munitions/blu-97.htm

 

Amplifying source would be the 1-34M, which you do not have nor do you have a need to see. Needless to say, CBU87 is a combined effects munition which does need much tweaking for DCS to model its effects even close to correctly. CBU87s can be used to kill tanks; the bomblet dispersion is also messed up, the game has fixing issues and a slew of other things...

 

At the end of the day it’s just a game and I’m happy to report there’s nothing wrong with any of y’all thinking 87s are for personnel and 97s are for armor. In my years with fighters, and with DCS, my personal technique is to fight what you see and if you have a weapon in the game that gets the job done like a rockeye or 97/105, just use that as a fill in.

[nighthawk2174]

They should still be given a small amount of AP value, they may not have 100's of mm of pen but still should be given some especially considering the tops of some armored vehicles are very thin.

[Frederf]

Both Mk 118 and CEM have ~200mm of penetration.

[NeedzWD40]

My own experience with the CBU-87 and CBU-103 suggests that the largest problem is the spread of submunitions is not uniform like they are with CBU-99/Mk20, which leads to cases where the subs do not hit or do not hit in quantity to do damage.

 

 

Having said that, the BLU-97 submunition should not be totally useless on armor and should be effective against APCs and older tanks as it does incorporate a shaped charge. Armor penetration should actually be the same as the Mk118 submunition in the CBU-99/Mk20.

 

 

 

Sources:

 

 

http://www.designation-systems.net/usmilav/asetds/u-b.html#_BLU97

 

 

https://www.wk2ammo.com/showthread.php?8097-BLU-97A-B-BLU-97B-B-CEM-for-CBU-87-USA

 

 

https://bulletpicker.com/bomb_-heat_-blu-97_b_-blu-97a_.html

[Fri13]

CBU-87 is anti-personnel/anti-armor, not anti-tank.

 

BMP-1, BMP-2, M113, M2, PT-76 etc etc are all tanks by the definition.

But none of them are MBT (Main Battle Tank) like T-54, T-62, T-72, M60, Leopard 1, M1, Leclerc and such.

 

There are various classifications and "tank" is covering many different kinds, starting from the original male and female tanks to modern ones.

 

There are lots of all kind anti-tank weapons, that many are not capable do much damage against MBT', but it doesn't make them less effective against other type of tanks.

[Auranis]

In any case, after talking to BN on Discord today I'll concede that the question of "how many bomblets should it take to kill an armored vehicle" is a fairly opinion-based topic given the current state of the DCS vehicle damage model.

 

That said, during that conversation I mentioned that it takes 3 BLU-97/B bomblets impacting a BMP-2 to kill it. After re-reading the lua comments on how damage calculation works, it seems that it would actually take 5 bomblets directly hitting a BMP-2 in order to kill it. This is because the simple_warhead function multiplies the power argument by 0.4.

 

I will have to do some testing to confirm this result.

 

Thanks to others who have posted sources regarding the penetration capabilities of the BLU-97/B.

[Fri13]

2 min google search would tell you CBU-87 is anti-personnel

 

It is Combined Effects Munition (CEM).

[Auranis]

Well, it definitely doesn't take more than 2 bomblets to kill a BMP, according to the test I just ran.

[Fri13]

In any case, after talking to BN on Discord today I'll concede that the question of "how many bomblets should it take to kill an armored vehicle" is a fairly opinion-based topic given the current state of the DCS vehicle damage model.

 

Well, what can be said for certain is that no vehicle commander is going to let their vehicle be under that effect, no matter what if they just can avoid it. Any light mortar strikes, autocannon firing etc. As any of those can be mission kill.

[nighthawk2174]

Also I seem to recall that in the past the number of submunitions was decreased for performance reasons? Am I off base with that or was that the case and is still in the game? Also Part of the issue is there is no simulation of mobility kills either. If one of these hits an engine deck or a track it would stop the tank. Maybe even damage the barrel of the tank or knockout sensors. We really need a more complex DM for ground vehicles. And maybe some fire effects added in if the engine is hit or the crew bailing out.

[71st_Mastiff]

I dropped CBU87's on infantry and no damage.

never mind they get killed by the bomblets.

 

 

but its just not on the score board as a kill.

need to add infantry to the A10 as a score points on the board.

 

infantry track ITT Syria a10a

 

:thumbup:

Edited October 7, 2020 by Mastiff

[Frederf]

Also I seem to recall that in the past the number of submunitions was decreased for performance reasons? Am I off base with that or was that the case and is still in the game? Also Part of the issue is there is no simulation of mobility kills either. If one of these hits an engine deck or a track it would stop the tank. Maybe even damage the barrel of the tank or knockout sensors. We really need a more complex DM for ground vehicles. And maybe some fire effects added in if the engine is hit or the crew bailing out.

 

That could have been my mistake. The visual objects are reduced (20 or so) but behind the scenes all of them are modeled logically.

[function129]

1 bomblet in the game should just equate to a vehicle k kill, unless its like an M1 abrams, T72 or T80 with spaced armor.

 

# of bomblets commensurate with the capability of the game to not crash everyones computers and server. program your hof accordingly.

[nighthawk2174]

Tbf if the bomblets can pen around 200mm of RHAE as was indicated earlier in the thread, there are no modern MBT's with that level of protection on their roofs, unless they have intact ERA on the top.

[NeedzWD40]

I thought I'd add that the A-10A seems to be able to utilize the CBU-87 effectively and that the A-10C can get better utility by turning off the rotation parameter with the 87 and 103. However, doing so results in an always uniform circular pattern instead of the more oval and destructive pattern seen with the Mk20/CBU-99.

 

 

In addition, the submunitions seem to have both the wrong model and behavior: the model is a PTAB bomblet with no parachute delay characteristics per the actual BLU-97 submunition. This makes me wonder if perhaps a huge part of the issue is the subs behaving like darts instead of parachute delayed as would be correct.