Amizaur

This is an interesting movie P.S. Nice - real IS-2, a test run after restoration

Here are some descriptions of efects on crew in the Western theatre (in British tanks) http://www.armchairgeneral.com/forums/showthread.php?t=142584 Be warned, not a pleasant reading And this also may be worth looking into, I'm going to try it: http://payhip.com/b/DO4I T-34's interior was full not only of unarmored ammo in boxes and in ready-racks on the walls, but also there were unarmored fuel tanks inside. Detonaton of APHE shell inside (or penetration of those fuel tanks located over the tracks) had usually catastrophic results. My suspicion is that most (not all) of the tankers that survived destroying of their tank (to write memoirs we read) - survived just because the APHE shell failed to detonate inside. Either because of fuze damage during penetration of the heavily sloped front armor plate, or because of simple malfunctio or sabotage (remember that those shells were produced by slave workers). So only the kinetic effects of penetrations occured - and descriptions like "the driver was killed instantly, the gunner lost both legs, I was only lightly wounded" fits well to penetration by pure AP projectile. I believe that description of penetration with detonation of APHE burster (especially 88mm one) in crew compartment would be little different (explosion, likely lost of consciousness, black smoke inside tank, burns). Even if it didn't ignite the ammo or fuel, it could kill the whole crew with simple overpressure, if anyone survived he would be burned. I do not want to say that this would be not survivable, but killed&wounded ratio would be much higher than in pure kinetic penetration, the chance for ignition of ammo/fule and explosion or fire - much higher, also psychological effect on surviving crew much greater - after penetratio the crew compartment would be hot, full of post-explosion fumes and black smoke, every easily flammable substance like paper or crew clothes could be smoking or even burning. I guess that in such situation 90% of crews - even if survived without wounds - would think only about escaping from this steel coffin and breath fresh air. I would also reccomend that when calculating the chance for crew wanting to immediately get off from the penetrated vehicle - few factors should be considered beside the morale. First - obviously - what is the chance that the tank will be penetrated again in few seconds and if they can do something about this, or not. I know it's very hard to estimate in a game-engine terms. It depends on how the crew feels about strength of their armor (Tiger crews less likely to escape from tank after single pentration than PzIV or T-34 or Sherman crews) and what guns the enemy have. But maybe it could be estimated somehow, even if it would be a single coefficient for a given vehicle in a given theater/period. Second - very important one - if the crew see the vehicle that penetrated them, or not. Crew that knows the threat is less likely to panic than a crew in a tank suddenly penetrated by unknow threat. Taken by suprise, and not knowing what hit them (often from the side), the crew is really likely to panic. Such picture emerges from read of various tanker memoirs and descriptions of their reactions for tank being hit/penetrated in various situations. This picture says, that most frequent reaction for tank being suddenly and violently penetrated by enemy shell - was to get out as fast as possible, and only then asses if the threat was real or not, if the tank is damaged/burning or in working state. If there is no more incoming fire, and the tank is ok or can be saved, the crew would get back in or put out the small fire and get back in. But only after escaping first . Immediate evacuation from tank (call it a panic) was almost guaranteed, if the penetration was sudden, by an unknown and unseen enemy, that can not be fought back and probably is just reloading it's gun to shot again... Of course it happened that the crew stayed inside and tried to continue fighting (even if some crewmembers were killed) but it was more rare than getting out. One another think I would like to see simulated is few seconds of a "shock" state for the crew after high-energy penetration of their tank. Even if they survive and want to stay inside and fight back, they should not react immediately, in most cases they would need a moment to recover/rally and return to performing their functions. I remember such "shocked" state for most penetrated tanks in CMx1 and it worked very well. I didn't notice anything like this in CMBO/CF...

Maybe it could be fixed by introducing a 0.1s delay in changing the vehicle status to "destroyed". This way the shell would manage to leave the vehicle trough the other wall ( legally penetrating it) and vehicle would become actually destroyed 0.1s later. Two things to take care on - first, that only the "first" penetration txt for a given vehicle is displayed, and not the second (about penetration of the other side). Second thing - that the "second" penetration from inside out, does not add damage to the vehicle itself and don't cause additional casualities among the crew. P.S. (warning - semi off-topic) The amount of damage to the crew caused by penetration of tank armor should be increased as well, IMO. The average number of wounded crewmembers should be doubled at least, the number of killed ones shoud be increased as well, especially for deadly APHE shells (like 88mm PzG39) or high-callibre high-energy APHE like 122mm APs. I recall a note by some German high-rank panzerwaffe officer about how Tigers are not anymore invunerable after intruducing by Russians 122mm guns. That lone Tigers should not come to the exposed positions on top of the hill to "take a look" because it's become deadly dangerous - lately some Tigers tanks were lost in such sitations penetrated by 122mm AP shells, and those were total losses, only one crewmember survived one tank, the rest were lost with whole crews. So it seems that 122mm AP was quite deadly when it fully penetrated - and it's understandable. But not so in CMRT 1.0. Average number of killed among cremembers from Panthers penetrated by 122mm APs (1000m) are in order of ~2,5 crewmembers/shot for side penetrations and only ~1.8 killed crewmembers/shot for front penetrations. Chances for catastrophic ammo explosion (resulting in all 5 crewmembers killed) were ~25% for side penetrations and ~12,5% for front penetration. In both cases the difference between front and side pentrations is visible, I guess that in side case of penetrations (thinner armor) the penetrating shell retains greater part of it's kinetic energy and it's taken into account in "damage" calculations. Average number of wounded crewmembers was much smaller than for killed ones. About 0,36 for side penetrations and 0.31 for front penetrations, no visible difference between front and side value. IMO the average number of wounded crewmembers should be at least twice the value of killed ones. All above values are based on a sample of 120 penetrations total (53 side, 67 front) so far. Prelminary 122mm AP vs PzIVH test shows that number of killed is higher than in case of Panther - but again I would expect much more 100% casulaity instances - in cases where the 122s AP big 156g RDX burster triggered and worked as designed...

Once in CMBN I did some tsts, in which I managed to penetrate the sides of several (like 7 or 8) halftrucks positioned in a row . I used 88L71 Pak. And I believe it would be possible as well in real life . Penetrating sides of 3 Sherman tanks in a row (this was also possible in CMBN using 88L71, IRC) would be less likely in real world.

Most of fuses in AP shells would need a decceleration caused by penetration of at least 20mm of armor to be triggered. This means it won't trigger hitting a branch of a tree, and won't tigger hitting an armored car or halftrack. But should trigger after penetration of nearly any tank side armor (everything thicker than abolut 20mm). The fuse of German PzGr39 was often damaged when it hit highly sloped armor (like T-34's front hull) - the great side acceleration caused jming of some moving parts in the fuse - and didn't detonate then, causing damage only with kinetic energy. That's why German tank commanders observed that it's hard to set a T-34 on fire shooting it from a front, but it explodes and burns very easily when hit from the side. Even if the AP shell detonates, it doesn't mean it desintegrates completly and won't fly any further. Usually only the hollow rear part of the shell (containging the HE filler) is fragmented, the whole front part of the shell (a solid piece of steel containing most of shell's mass) would continue on it's path (sometimes it may start tumbling, sometimes not). It may penetrate the other side of the tank and continue flying, and if it retains enough energy it may kill some other lightly-armored vehicle.

And it surprises me how reduced lethality have the bursts that happen INSIDE of the penetrated tanks . Sometimes it really seems that crew is a bit safer inside of a tank being penetrated than being caught outside by a falling ricochet . Especially average the number of crewmembers wounded during tank penetration is very small, several times smaller than average number of killed ones.

Well, russians AT guns (at least 45mm ones) fought this way ! Sometimes they pushed unlimbered guns forward following the advancing troops, so they could give them AT support in any moment. They were assaulting on foot with AT guns, no kidding. But they didn't fire on the move, I guess .

When you plan all your actions in real life - minute after minute

RT is very playable right now , regarding to gameplay it has some minor things to be corrected, fine tuned or improved, but nothing really important IMO. Patches would only make game even better. Well, forgot about the shadows issue. I have problem on Radeon 7950. I have to play with shadows off, because they look bad, same like the guys above.

I'd like to see it coded someday. The "sky in the background" check, "contrastin with bacground" check and "being in shadow" check. Even if the bonuses (or penalties) were small (like +/- 30%) it would make spotting in game much more realistic and would promote carefull and realistic tactics regarding positioning of own units. In real life a "bonus" to concealment (or to detection probability) for target in deep shadow, or target against a sky background, would probably be +/-100% or more. Dramatic difference and very important factor.

I think that it would help if the target arc worked this way: - unit ignores targets outside of the arc (as now), but - if unit "locked" (started aiming/firing sequence) a target that was inside the arc and during this the target moves out of the arc, the unit should NOT break the aiming. It should continue aiming/firing seqence even outside of the arc - my proposition is that it would continue targeting the "escaped from the arc" target for at least 15 seconds (so like single "target briefly" command). 15 secons should be enough to fire at least one shot. After 15s unit can break the "lock" and return to guarding it's arc.

I used immobilised target tanks so far, so they had already red damaged engine and tracks. Now I use fully operational ones, and I see that red Engine damage happens with hull hits. Sometimes tracks become damaged (dark green or yellow) with hull penetrations. But not radio or weapon controls, never. Radio seem to be "turret mounted" when it comes to damage calculations. Those tests are very time consuming lot's of data to note. Where hit, with what effect (penetration, partial, spalling, none), tank destroyed or not, what casualties and wounded, what damage, does it burn, effect on morale.... I wish there was some kind of debugoutput txt with contained at least some of this data about every hit, and could be saved.

But there were several platoon commanders and they all were experiencing the action around their position. I as a player CAN'T watch all the action everywhere simultaneously. I can watch one place at a time only. The rest of action on a whole map is lost for me. With replay feature, I usually play it 3 times - watching actions on left side of the map, sometimes the center and on the right side of the map, and separately replay some interesting moments and actions from close range. It's the only way I can control actions of all my men and vehicles on whole map and know what is going on everywhere. If it was to be a realistic simulation of a force commander, I would only have map and hear/read raports of what is happening. Sometimes I could use a binocs from a single point of view, ground level. I'm not interested in such hiper-realistic sim. I prefer to watch what is going on - it's 80% of the fun for me. And I can't in real time. That's why I don't play RTS games, and prefer turn based wargames.

I think it's possible in game - because the damage is probably somewhat "random" (I mean it's not based on the point of hit) so there is chance that such penetrating hit would end without any damage and without any casualties. The chance is quite high, but it depends what hit's it. Currently I'm testing penetration results of 122mm AP against a Panther because I had feeling the results (low number of killed and wounded crewmebers) were not realistic for such heavy and deadly shell. No conclusive result so far, test is in progress, but: So far I noted results of 76 side and frontal penetrations and you now what ? Damage (like gun, coax, weapon controls, optics, radio ect) happens ONLY for turret hits. I didn't note a single damaged piece of equipment in all hull penetrations (56), but almost every turret penetration caused damage (19 out of 20). So there is really great chance that upper hull penetration trough hull MG will not cause any damage - in CMRT . And some chance that the bow gunner woulds survive it - about 50-60% (it may be the driver who get's killed instead, or there would be no casualties at all). As for real life - I don't think it's possible if the bow gunner was in his place. He would die most likely. And I don't think the bow MG would be in workin state, after that . As for casualties, in 16 front hull penetrations I had 1 that didn't kill or wound anyone. In 7 mantlet penetrations there were 2 that didn't kill anyone (there was one wounded once). More results later. P.S. I should clarify something: For "damaged" equipment I counted only "red damaged" ones. So in fact destroyed equipment. I didn't have any instance of anything being "red damaged" with hull penetration. Only with turret hits. "dark green" damage happened for hull penetrations too. But "dark green" happend also for HE hits and even close HE ground explosions (missed HE shots) too.

I see tho penetrations there, the bow MG and the commander's cuppola (which would show txt "hit:top turret" ) What was shooting at this Panther and from what range ?

Good point. This could happen sometimes.

Yes, more vibrating of the hull could cause more damage. But my example was to show in what general ballpark the strength of the "hit" would be. Even with more vibrations, I still think it's far from doing any real damage to the tank internals. And I'm talking about AP hits only. I do not know much stories about something inside the tank (radio, engine) damaged from the "shake" caused by an non-penetrating medium-calibre AP hit ! There are some known examples of ricochet/non-penetrating hits causing damage, but it always has beed damage to elements that were directly hit or attached to the plates that were hit, so deformations of plates caused by hit was directly transferred to those elements. But not by the "shake". I don't know any story of an engine being damaged by a front armor AP ricochet. It's a way too small shock/shake, as I tried to explain. Maybe an 122mm AP shell hitting a Tiger (and not penetrating) would have a chance to shake it enough to do something... 85mm AP hit - I would give no chance... As for HE shell hits on tank - I do not have enough knowledge to estimate what kind of "shake" an HE shell would make against a tank. It depends a lot on many variables - quantity of HE, at what range from the armored plate the charge detonates (so what kind of fuse is used), an probably more. I can only base on tanker's memoirs here, and known incidences.

You are partially right, partially not. The shell-tank collision would move the armor plate faster than tank-wall collision. So more vibrations, you are right here. But tank-shell collision won't move the armor plate "much more" than tank-wall collision. Because it's depentant on momentum and not on kinetic energy. And momentum is same in both cases. The great kinetic energy of the shell would be dispersed to deformation of the armor and the shell and to great amounts of heat, only part of it would be actually used to propel the armor plate. How big part ? You can calculate it using momentum instead of kinetic energy. In example of tank-wall, almost all kinetic energy would be used to shake the tank, because of slow speed the loses on deformations and heat would be minimal. That's why those situations are comparable in some regards, even though there is great difference in the kinetic energies involved. I used the tank-wall example because it's most comparable thing I could think of, that is easy to imagine for everyone. Everyone can imagine what it feels like if a vehicle hits hard wall at a very slow speed of 0,5km/h. It's something we know from our everyday life, people are good in estimating results of collisions at slow speeds. Not many people can "imagine" results of collisions of objects going 700m/s, because it's not a part of out everyday experience, so we can't imagine how it is like when a 10kg / 700m/s object hits a 56ton vehicle, what it feels like. I can't imagine that too. But I know physics enough to calculate another collision with same (or very similar) reaction of the tank hull, but happening at slow speeds so I can imagine it. Good example of similar problem would be trying to imagine how it is like being hit by a bullet. It's impossible, you won't know untill you try . But knowing the physics, knowing that the efect you think of (how strong the "hit" would feel) is ruled by momentum conservation principle, you can calculate a different collision happening at slower speeds, closer to your everyday experience, that you CAN easily imagine. For example if you would like how it feels to be hit by a 9mm pistol bullet, of course while wearing a bulletproof jacket - let's calculate: 7.45g * let's say 380m/s = 2,831kg * m/s. Now we need to increase the mass to decrease the speed, BUT keep it reasonably similar in "feeling". So we WON't use a mass of 74,5kg going at a speed of 0,038m/s (so barely moving) because being "hit" by such object is something very different than being hit by a bullet. You would barely feel that because of the slow speed - even though momentum is the same. Let's think about something that can really "hit" - so maybe speed of a thrown stone, hm let it be 10m/s. To have identical momentum as 9mm bullet, the stone have to weight 283g. Better would be to imagine a small lead weight, it would be smaller. So imagine you are hit in the chest with 283g lead weight thrown at a speed of 10m/s. This is something you can imagine. So I caan say you, that the feeling would be _similar_ like when being hit by a 9mm pistol bullet while wearing good bulletproof west (with a ceramic plate). The results of those two collisions would be quite different, if the bullet actually hit your body and dipersed it's great kinetic energy inside your body, doing horrible damage to your internal organs. A thrown 300g stone don't have the energy required to do such damage. If you had only a simple "kevlar" type jacket and the bullet hit you, it would break you a rib and leave a big and painfull bruise. The 300g*10m/s stone would probably only leave a bruise, and much lighter one. Again, the stone don't have enouh energy to make serious damage, it's not comparable with bullet in this area. But as long as your body is well protected (good kevlar vest with ceramic/steel plates) and the bullet does damage only to the vest, not your body, the results behind the vest are almost identical. You feel a hard hit. Both hits would be very comparable. It's not identical, I admit. The bullet hit could feel "faster" and bit more "violent" and be louder But still a thrown stone or weight is the best _comparable_ thing we can easily imagine, and in many regards the hit feels really similar. Now the bulletproof vest that absorbs almost all of the kinetic energy of the bullet, but transfers the momentum - can be compared to the tank armored plate that is hit and deformed - almost pierced - by the shell, and your body (with internal organs) which feels only the "hit in the chest" and "shake" - can be compared to the rest of the tank - with people inside that feel the hit and various things/mechanisms that can be damaged by the shake. You are always doing it by momentum . Only using a light hammer or heavy hammer. Both hammers do different kind of damage, but they use momentum to push/ove things. Momentum is always present in collisions, both slow and fast and ultra fast, for both light and fast objects and slow and heavy objects. And it's always conserved, never "disperses". Every time you want to calculate how one object would move/behave as a whole after colliding with another object, you use momentum ONLY, forget about kinetic energy. Kinetinc energy is not retained, it's diffused in collisions - faster the collision, greater part of kinetic energy is dispersed to deformations, heat, light, sound, ect and smaller part is "used" to push things and move them. This is why we use fast projectiles to damage something - those deformations/heat to the target is called a "damage" after all . It SEEMS like there is momentum important in slow collisions, and energy important in fast collisions. It's PARTILLY true - as in slow collisions energy doesn't manifest itself (no bang, sparks, holes, or explosion) and in fast collisions energy manifests itself so evidently (a flash, sparks, flames, pierced armor and lot's of damaged things) that we tend to forget about momentum. But they are always present - both, and are always "working" - both, momentum and kinetic energy. They just do different things. Depending on what kind of effect/result you need to calculate/estimate, you choose momentum or energy in calculations. You want to know how things would move after collision - momentum only. You want to know how much energy would be released, how much damage can be done, how much heat can be generated in collision, how much steel deformed, how much armor pierced - you use kinetic energy (or energy at all). Cheers!

The knowledge of the energy is needed for us only when it comes to the process of damaging things (outside or inside of tank). This process requires energy. Then we can think about how much energy would be spend on damaging things and how much would turn into heat harmlessly or into residual kinetic energy of various elements. But for analysis of the collision between tank's armor plate and the shell (or tank's plate and reinforced concrete wall) and estimation of the resulting "shake" - the momentum is all that we need, kinetic energy is not usefull here at all - from the very reason that it's not retained in collisions but tends to turn (in lesser or greater part) to heat.

First, I'm talking about AP shell. No detonation (beside 50g of HE filler). Just pure collision. About the G-shock: And what if the delta-v occured in even shorter time ? Imagine 1/10^6 ? Would that mean the shock would be 12000g ? Such shock should pulverise whole tank, right ? Not really. Not in 1/1000000s. IF we managed to transfer the momentum in 1/1000000s (of course it's impossible for such large objects) then it would be really 12.000g but for a VERY SHORT TIME. Sitting in a tank or a car you wouldn't notice any difference between 12000g in 1/100000s and 12g in 1/1000s (well, the sound could be different). Because what really counts is what kind of damage can cause such impulse. It is said that a limit of serious damage for human head in a car crash is about 50-80g. It doesn't mean that a human head can withstand 50g - continuously. The above limit is - precisely - 80g for some miliseconds. If the time was twice as long, the g-limit would probably be about halved. And if time was halved, the limit for human head would be probably almost doubled. Because what realy counts is what kind of damage would this head suffer in such epizode (80g for xx miliseconds). And what causes the damage ? Acceleration does ? No. A force causes damage - by deformation, and deformation in turn requires energy. If we apply a large force (resulting in large acceleration) but for a very short time, we don't transfer enough energy to cause much damage. From some point up, it doesn't matter what acceleration is generated, if only the energy is below some threeshold that can cause damage. It's because of elasticity - the steel of the tank, the bones of the skull would simply bend or compress and accumulate the energy that was transferred in very very short time, and then release this enegy much slower transferring it to the rest of the tank/rest of the head. Same for tank. If the "energy of the shake" is below some threeshold, you can transfer it as rapidly as you want and you won't make more damage that maximum possible - you have only X of energy and it can cause only some limited amout of damage. On the other hand, if you transfer the energy more slowly (by gently pushing the tank) you won't' do any damage at all . Nothing stops instantly, right. But "instantly" is good enough approximation in this case. The point is that a shell hitting the armor transfers the momentum in very short time (about 0,3ms). But it transfers it to the part of the plate it hit. This part of the plate transfers it to the rest of the plate, and whole plate transforms it to the rest of the tank. Those plates would bulge, bend a bit, slowing the process of energy transfer. A tank hitting a reinforced concrete wall with it's thick 10cm armor at speed of 0,5km/h would also stop very quickly - I don't expect the armor to bend much, it won't deform much, the concrete as well. I guess it would be in order of 0.01s before the whole front plate stops, and then it would stop the rest of the tank it's welded to - but again some bending and compression would happen that would slow down the process. In both cases the energy was transferred quickly to one part of steel (one plate) and then it had to be retransferred to the rest of the tank, which took much more time as the tank is not an ideally rigid body/structure. It's elastic body. It's fact that the shell/armor interaction was quicker than concrete/armor interaction, generating more g's - but only more g's regarding the very plate that was hit. The process of transferring the momentum to the whole tank is much longer and because of that those two cases are comparable in regard of delta-v. And comparable in that what kind of damage and how much of damage they can cause to tank internals. I admit that AP hit can cause more hull vibrations (because of the armored plates bulging) and this can cause some more trouble for things like radio or engine valves (things vunerable to vibrations) but the overall "energy" and amplitude of the shake is very similar in both cases. Or at least I think so. Sometimes when duration is very short, it achieves some kind of "optimum" and there won't be much difference in physical results (damage) if you make duration even shorter. It becomes effectively just "instant" and then only the energy of that "instant" transfer matters. Shorter time, but still same energy - results practically the same.

I don't believe 85mm HE shell would seriously shake a tank weighting 44-55 tons like Panther or Tiger. But it can seriously shake the armored plate it hits (especially thin side ones, such plate would bulge momentarily) and damage anything that is mounted on this plate (like radio) or too close to it. And 85mm "HE" is really a fragmentation shell (doesn't contain too much explosives) IIRC. The 76mm HE was more effective in HE role than 85mm one. It happened that HE explosions on armor caused damage (and even engine fire - by loosening the fuel lines and varous valves in the engine compartment) but usually it was either heavy bimbardment of 76mm shells, single 122mm shells or arty shell explosions in proximity. Some Tiger tanks which survived bombardment by heavy allied artillery (western front) but they all had to realign their gunsights before they could fight. As for AP hits - 10kg 85mm AP shell hitting a tank at 700m/s has 7000kg*m/s of momentum. A Tiger tank weighting 56 tons that would absorb such a hit, would get a velocity change (whole tank) of of 7000/56000 = 0,125m/s so 0.45km/h. Being hit by 85mm AP shell from close range would give a shake like if the Tiger going 0.45km/h hit a reinforced concrete wall or a pillar of a bridge with it's front armor and stopped instantly. It can be felt, but it's definitely not a big shake. Of course He hit was louder. And being close to the very armored plate that was hit could be not healthy.

One 85mm HE shell vs massive 40-50 tons of tank (thick armoured steel) is not comparable to a computer case vs a hammer . Tank would barely move when hit. Maybe a 155mm HE shell vs tank would be comparable .

SOME variability is good thing. I mean - after AP or HE hit at the tank MG it may become damaged (usually) but it may not. A HE hit close to unbuttoned crewmember gives very good chance of killing him, but he may have some chance to avoid the shrapnel, or - like someone said - he could just momentarily lower his head shouting something to his driver or his gunner, at the very moment the shell struck. He was just lucky. Things like that had happened. And some randomnes - like when a HE hit at front turret would generally generate damage to things that are located nearly (optics, gunsight, coaxial MG, radio antenna) but SOMETIMES it can generate damage to something less related, like the engine or bow machinegun. But something like total randomnes or "everything is possible sometimes" so for example an HE hit against the rear hull damaging the front bow MG or HE hit against top turret damaging a track - sorry, I can't imagine that.

In my testing I observed clearly that 85mm, 122mm and 88mm HE shells leave decals same as AP shells - so ricochet decal or penetrarion decal. Strange that you haven't got decal.

The front turret armor penetration by 8,8cm HE from Tiger I. Sorry for small screenshots, photobucket is not good for that... (it resizes the pictures to 1024x).