question: what is the probability of weakpoint hit?

[kevinkins]

Let's remember when we get to PBEM / multiplayer. players will need to agree on the database they are using. Or perhaps the game will only allow the official DB to be used when playing against another human.

[gbem]

What do you mean? Many sources show the M289 at 600mm penetration, in game it's 550 a 8.3% down grade and the M829A1 at 700 and 640 in game a 8.57 % downgrade. So yeah it's not exactly 10%. What are the APDamage number you are using in the game for the M829, DM-33, and BM22,26,29,32 and 42?

The Soviet standard for calculating the penetration limit of armour piercing projectiles is V80, meaning that the expected consistency of achieving full armour perforation given a certain projectile velocity must be 80%. In formulas, V80 must replace V50 (50% chance of armour perforation). For example, if a certain projectile has to penetrate 500mm of steel, then at least 80% of all projectiles of that type must achieve that standard. Also, the Soviet criteria for a full armour perforation dictates that 80% of projectile mass must be recorded on the other side of the target plate as opposed to U.S Army criteria which only requires that a hole is produced in the armour such that light can be seen from the other side. Overall, Soviet standards were not only stricter, but the steel they used for targets was sometimes of a greater hardness than NATO targets. In reality, the given penetration data may be an underrepresentation of the actual achievable penetration of these shells.

if you wish to compare american and russian data you need to mark down american data by a large margin.... V80 vs V50... 80% of mass vs 3mm hole... high hardness vs medium hardness plate...

Paul Lakowski stated that perforation values for V80 vs V50 alone could already make an 8% difference

similar disparity`s also occured with ww2 ammunition
the comparison between the M62 and the BR-365A can shed some light on the sheer disparity between american and soviet penetration criteria

penetration criteria without adjustment
BR-365A
penetration at 500m vs 30 degree plate: 91mm
M62
penetration at 500m vs 30 degree plate: 93mm

ww2 ballistics and gunnery adjusted penetration
BR-365A
penetration at 500m: 123mm
M62
penetration at 500m: 116mm

the difference is considerable between american and soviet penetration criteria and they cannot be used interchangably without the odermatt equation

[gbem]

the DM33 3BM32 and M829 were rated at similar in close range perforation therefore i gave them 560 AP each however the vant had less penetration at range reduced to 35000 apdamagerange value...
correction: fixed the data changing 40000 to 35000 long range penetration is now equivalent to the DM23 with short range penetration being much higher

the 3BM42 "mango" being a segmented penetrator designed to defeat composite armor but perform worse against a solid steel plate i uprated to 580mm as the testing data vs an RHA plate would be biased against it

segmented penetrators like the DM53 M829a3 and the 3BM42 need to be uprated in their displayed penetration value vs composite armor as these tests were conducted against monoblock/monolithic/solid steel plates

i gave the mango similar apdamagerange as the DM33 and reduced M829 apdamagerange to the DM33`s levels as the 3bm-42 was stated to have superior long range performance than the vant (430mm vs 520mm)

here

[gbem]

Let's remember when we get to PBEM / multiplayer. players will need to agree on the database they are using. Or perhaps the game will only allow the official DB to be used when playing against another human.

if they introduce MP they need to fix the 3bm32/42 and DM33 penetrations (m829 outperforms these rounds for some reason)...balance out the silver bullet with the svinets... introduce per tank weakspot values and weakspot armor value... and introduce stuff like a scatter order and a cover SOP

[Werezak]

I am 100% certain that yes, people will go through the trouble of modding at least several dozens of vehicles.

[gbem]

Perhaps in the future there can be one moddable global value. I doubt anyone ever will go through hundreds of vehicles and calculate the 'correct' values for all armor facings.

ive done it for the leo 2a4 and the T-80U... subtract the lower frontal plate then compare the cross sectional area vs any weakspot on the hull and turret... for the leo 2a4 i counted the 400+mm area near the turret ring and for the T-80U i counted the 200+mm cleavage the 200+mm area near the mantlet and the 300+mm turret cheeks... the rest of the area is already resistant to most modern rounds soo i did not include them

this gave me 6% for both the 2a4 and T-80U
and a weakspot value of 400+mm for the 2a4 and 300+mm for the T-80U

granted its a bit of a hassle to perform...

[noooooo]

ORIGINAL: gbem

Let's remember when we get to PBEM / multiplayer. players will need to agree on the database they are using. Or perhaps the game will only allow the official DB to be used when playing against another human.

if they introduce MP they need to fix the 3bm32/42 and DM33 penetrations (m829 outperforms these rounds for some reason)...balance out the silver bullet with the svinets... introduce per tank weakspot values and weakspot armor value... and introduce stuff like a scatter order and a cover SOP

I really hope MP is released before spending effort doing all that... Except the cover SOP/scatter order one which I think would be very impactful and useful

[gbem]

I really hope MP is released before spending effort doing all that... Except the cover SOP/scatter order one

fixing the 3bm32/42 and the DM33 and adding the svinets isnt hard... also helicopter BPs should be movable imo... and the hind should be "fixed wing" XD

[Lieste]

ORIGINAL: Veitikka

ORIGINAL: Lieste

I seem to recall this was at one point a triangular distribution (from 100% at 85% coverage, to 20% at 0% coverage)

Is this not still the case, or have I miss-remembered?

I don't remember all the discussions and experimentation we had, but currently there's a simple 15% random chance for it.

I think this would be an improvement (it would make a difference between weapons with a 99% penetration potential (15% pen chance) and those with only a 60% penetration potential (7.5% chance).
It doesn't require the additional (impossible) research, or complexity explosion of weakpoint size/'form' for each face of a complex shape, using only the data already present in a consistent, predictable and coherent way.

[Lieste]

ORIGINAL: dpabrams

Hard to be objective, we all have bias. We are slaved to what data there is and much of it is grey. The database for AB is really good when I compare to my sources, which are the same sources as everyone else. I have found some data that I corrected based on the weight of other sources. For example, small caliber HEI that had NO AP rating (Marder 20mm), incorrect missile speeds (TOW's AB rated for 178 mps/ actual 320 mps) and the 73mm 2A28 early warhead with a range of 1200 meters (should be 9000-1000) to name some. You can't expect the Dev's to get it all right but AB is very close 90% of the time in my opinion. That's why we can mod the data base.

Be careful with ATGM (Also SAM) speeds. What is important is time to range, not peak velocity.

A 178m/s missile will fly to 200m in 1.1s, vs the .6s of the 'correct' 320m/s... but at 3750m the 320m/s version will arrive 9s sooner than it should, at 12s vs 21s

As these are (predominantly) standoff weapons, fired at long ranges from light vehicles or helicopters, rather than knife fight weapons, the important timing is for the 'far' range, where the magnitude of the error is also going to be larger. (eg. 9s vs 0.5s)

[gbem]

that would be true for all rocket motors... peak velocity =/= average velocity... it must be noted that a missile continuously accelerates towards the target unlike bullets or projectiles which actually decelerate towards the target...

question... isnt the average velocity of a TOW 187.5 m/s? 3750 max range and 20s time to target?

[Lieste]

Tow2a 20s (some manuals say approx 21s), Tow2b 21s to 3750m

On acceleration:

Missiles have a short burn, some exhaust their motor in the launch tube and coast the whole way. Others are ejected, then boost and coast. TOW is ejected, motor ignites at 7-8m, burns only for 1.5 s, peak ~320-330m/s, coasts to max range over the next 19.5s
Very few are still accelerating at their maximum range, and then only if their range is limited by factors other than kinematics. Those which may still have an active motor, are almost always only using a low thrust arrangement as a sustainer/gas generator, to limit decay of energy, and the bulk of their acceleration still comes from the high thrust boost motor or boost phase of a multi-phase motor.

The velocity/range profile for most SAM/ATGM is broadly similar to a (draggy) shell, but with longer times of flight and an acceleration from a launch speed to peak over the first second(s).

e.g 9M119M launch ~200m/s, boost 800m/s within a very brief burn, then a long coast to their max range of 5000m at an "average" velocity (not actually flown for any duration) of ~350m/s

[gbem]

Missiles have a short burn, some exhaust their motor in the launch tube and coast the whole way. Others are ejected, then boost and coast. TOW is ejected, motor ignites at 7-8m, burns only for 1.5 s, peak ~320-330m/s, coasts to max range over the next 19.5s
Very few are still accelerating at their maximum range, and then only if their range is limited by factors other than kinematics. Those which may still have an active motor, are almost always only using a low thrust arrangement as a sustainer/gas generator, to limit decay of energy, and the bulk of their acceleration still comes from the high thrust boost motor or boost phase of a multi-phase motor.

afaik russian missiles like the R-77 vympel have a multiphase motor where they continuously accelerate towards their target in contrast to other missiles like the AIM-120 which only have a boost phase rocket motor...

i always thought the russians opted for multiphase while nato went for boost phase motors... ohh well.. never knew the refleks was a boost phase missile... err is it? or is it multiphase? tankograd does mention cruise velocity...

[kevinkins]

Gee .. I can't wait to play you in multiplayer / PBEM. [:D]