Red Orchestra's Tiger x real life Tiger

[Dr.Luuvalo]

I mostly agree with Sgt.Rock's post, exept that if my sources serve me correctly, pure tungsten is actually somewhat denser than depleted uranium with density of some 1925 - 1950 kg/m^3 against uraniums ~1900 kg/m^3. There seems to be some disagreement over tungstens actual density, but all sources state its density over that of uraniums. However, tunsten carbide that has been used in tank ammunition to some extent, is less dense than DU.

To the matter of german steel vs russian steel, I must point out that cast steel armor is notably less effective than cold rolled steel. I cant remember how much more so, I'm too lazy to dig up any book about the matter. Many t-34 tanks had cast turret and/or hull and all IS-II hulls and turrets were cast. Germans also used cast parts, saukopf style gun mantlets seem in many german armor, and panthers gun mantlet were cast to name a few.

Btw, are penetration caps modelled in roost? as sloped armor seems to be dubiously effective in deflecting ap shells.

 

[Justin S.]

The problem Justin is this goes back to what I was originally saying. You tend to get inconsistencies when you just use arbitrary values.



If you use calculations based upon the actual physics, there shouldn't be any inconsistencies because the laws of physics will not allow them to occur in the first place.



If the armor penetrations are actually governed by physics calculations which take into account the capabilities of the 76mm shell fired at a certain velocity and range and angle, then why would you get a penetration from a certain distance that did not happen in real life? If it did not happen in real life, then calculations which reflect the real world data should not allow it to happen in a virtual world either.


However, if you used arbitrary values of "gun power" and "armor strength," then you can see where this could lead to highly unlikely situations happening on a consistent basis within the game world.

I understand your point, but think it is too hasty given our lack of hard information on how they built this game. I take issue with endless, unverifiable speculation.

Outliers certainly occur, but I do think this term/phenomena has been overused by the devs to explain potential gaps between "real world" performance and game results. However, I am not ready to jump to the conclusion that this is due to a sham- that all the talk is lies and that they really use a glorified system of rock, paper, scissors to resolve armor engagements.

Additionally, even if they researched and implemented reliable data, we dont know how it was implemented, how the engine interprets and resolves this data, etc. I dont know nearly enough about game development or programming to comment on how this complex process plays out. Again, I must reserve judgment.

To be clear, I side with the community in that the devs have often overestimated the solidness of their model and have dismissed valid concerns. On the other hand, the community can be quick to dismiss their labor and dedication.

 

[Jack]

Nice post Justin. The only way things will be resolved is if we take an objective standpoint, so as you say we cannot be too quick to jump to conclusions one way or the other.



@ Dr. Luuvalo: I don't think different piercing caps are modeled. The devs have stated (in a round about way) in the past that the effects of blunt-nosed AP on different armor have yet to be implemented.

The only difference currently seems to be between APCR and regular AP.

 

[Sgt.Rock]

Im posting here to clear up some misinterpretations of what I said (I had a little trouble getting all that infromation down to that small), as well as elaborate on certain details.

Starting off, Jack, you got half the truth but not the other half. The length and diameter of the penetrator actually does have a lot to do with penetrative abilities of it (Bad english).

You did get the disadvantages right, as it gets longer and thinner, it gets weaker, and more likely to bend or break (Theres more to this, and ill explain in the next paragraph). This is due to acceleration, not flight, as the penetrator has to withstand an acceleration the peaks over 50,000 G's ! As I said, some of ways to counter this weakening is stronger/longer SABOT (not penetrator) petals, making the penetrator out of stronger alloys, or increase machining quality (techniques and the like).

Now the advantages. As the penetrator gets longer, its able to penetrate more (more mass concentrated at a small point), but the wieght increases (which is why, in the last paragraph, they make it thinner, which should have its benefits in itself, making the point of contact smaller). Another reason the longer the penetrator the better, is that the penetrator erodes as it penetrates, so with a longer rod, you have more length for it to erode. All of this is described as I said, and what you said, an l/d (length divided by diameter). So basically the longer the better, but theres a catch. The longer rods are also effected by lateral force when coming into contact with armor, so penetrators have to made thick enough to withstand these forces, which limits designers from making them a desired length (take a look at HEAT and standoff distances as well).

now you gave a 5:1 ratio before having to use fins, which may or may not be correct (I really dont know ), but you can go a very long way in terms of l/d before the round becomes unstable in flight (with fins). The U.S. M829A1 APFSDS round, although semi-old, has an l/d ratio of 33:1 ! The round itself weighs 4.9 Kg and is 78cm long. If my math is correct, that would make the diameter 2.36 cm . This round penetrates so well that it was nicknamed "silver bullet" in the gulf war, in fact, I believe there is one account of a round fired from an M1A1 Abrams that went clean through two T-72's and hit the ground behind them !

So, essentially what Im saying is that.......... Longer and thinner (l/d ratio) = Better performance (penetration and the like). Designers do try to make them as long as possible.


Now Dr.luuvalo, Im not sure if your right or not about the densities, but heres my figures. Most DU alloys used (mostly DU and titanium) by the U.S. average out around 18.6 g/cm^3 whereas most Tungsten alloys used (mostly Tungsten with nickel and iron) average around 17.5 - 18.5 g/cm^3. I'll explain even further.

The Germans use a sintered tungsten alloy, a mixture of dense but brittle grains of tungsten held together in a tough slightly flexible matrix of nickel and iron. Their main gun is the 120mm L/44 The German DM33 is 4.6kg and has an l/d of 21:1. The DM43 is 4kg and has an l/d ratio of 30:1. The DM53 (which uses a lengthened 120mm L/55) is longer and has a higher velocity (sorry, thats all I know ).

The U.S. fields the M829A1 which I described earlier (Mostly DU and alloyed with 0.75% titanium). They also have the M829A2, which is essentially the M829A1 but with a Carbon fiber Sabot. Theres also the M829A3, which is supposed to have a kinetic-energy precursor to combat heavy reactive armor.

Now the Russians (since this is dragging on ill wrap it up). In earlier APFSDS models, they actually used steel (which has a density of 7.8 g/cm^3), this is in part to many factors, including easy production as well as the need to arm vast amounts of tanks (they produced 20000 T-60's alone). Since the round was steel, it was very light (reletively) and could reach velocities of 1800 m/s (compared to German 1650 (DM33), 1740 (DM43) and US 1575 (M829A1) 1680 (M829A2)) They used a ring Sabot spool, so the fins had to be large enough to touch the barrel, which created large drag in flight and decreased long range performance. The round length was limited by their tanks, so the round could only reach 70cm. They also used the BM32, which was DU and only 49cm in lenght . They also used the BM42, which was kinda like WW2 APCR rounds, it had a tungsten core and a steel shell.



Well, its way more than yall ever needed to know, but a little knowledge can be a dangerous thing.

 

[Rameusb5]

RO:OST is already a technically impressive game, but we wargamers can never have enough. The thing about this game, is that it's the only realistic/technical combined arms WW2 game that will ever be created(Unless Tripwire makes others).

Who do you think will make another RO? EA? IW? Nope. Only Tripwire.

This is the only chance we have of seeing realistic WW2 combat, and the community would like to see that. It has already gone a long way, more than any other WW2 game ever made. I am incredibly thankful towards Tripwire for creating such an amazing game, I only hope they keep polishing it.

I would be very happy if we indeed had accurate calculations...

Actually, WWII Online is exactly what you're talking about. So RO:OST isn't the only game like this.


I am a bit surprised that the Soviet 76mm can penetrate the Tiger frontally in RO:OST. I'll test this tonight when I get home.

I've already tested the 76mm vs the Tiger's side armor and found that it took 3 hits to "destroy" the Tiger. For some reason, there's a game mechanic where you can kill a vehicle but not hit any critical system. I'm not certain if these hits penetrate or not.

 

[Matanga]

First of all great thread

Second: I don't know much about armor/tanks etc (even though thanks to this I'm learning) but I do know about coding.

And I tell you guys that trying to find an algorithm that models something as complex as tank combat plus making it fast enough so It can run in real time (I mean no point it getting perfect accuracy if it takes 3 minutes to find out if the round penetrated or not) is not an easy task.

So please keep in mind that "tuning" tank combat will take some time and certain degree of experimentation.

Just my 2 cents

 

[kabex]

Actually, WWII Online is exactly what you're talking about. So RO:OST isn't the only game like this.

WWIIOnline is in its own category, since it's not a "multiplayer" or "pick up and play" game or what have you.

 

[Jack]

Another important thing that needs to be remembered Sgt. Rock is that concentration of a mass versus having a larger caliber is better when dealing with identical projectiles of equal mass.

A 2 pound projectile that is 20mm in caliber and longer than a 2 pound projectile that is 45mm in caliber but shorter will concentrate more energy.


However, this is because they both have the same mass, and if velocity is around similar values as well, this means they will obviously bring identical kinetic energy to the plate.


Thus, if you bring identical energy, but one is more concentrated, it would generally be expected to penetrate better.


However, we must then take into account situations where mass is not identical, such as the difference between the Pzgt. 39 88mm fired from the Tiger's cannon, and that fired from the 75mm L/70 gun of the Panther.


According to the first impression, you would think that as the 75mm shell has a smaller caliber and higher velocity, it would have better piercing capability (higher velocity concentrated in a smaller area). But, when it is considerd that the 88mm shell weighs around 10kg versus the 7kg of the 75mm shell, the 88mm projectile actually brings more kinetic energy to the plate and has better performance thanks to this and the fact that it comes closer to overmatching thicker plates.



So, although the 88mm is "broader," it also weighs substantially more, while moving at a similarly high velocity. This is just one more reason why reducing caliber is not necessarily better, and indeed, may prove counter productive if the shot becomes too long.

Another reason the longer the penetrator the better, is that the penetrator erodes as it penetrates, so with a longer rod, you have more length for it to erode.

Hmmm...isn't this a disadvantage? This is what I meant before when I said you have to "push more material through the plate." The longer rod means that more time passes before the entire penetrator has entered the plate. Granted this time is very fast, but during this period, the front of the penetrator is absorbing counter forces from impacting the plate, thus the longer these forces act, the less energy is retained by the time the rear portion of the penetrator has 'caught up.'



The problem is none of this is a clear cut solution. All of this falls somewhere on a curve, you can't infinitely make a penetrator longer and longer and get better performance, which is what my original point was. Lengthening the penetrator while decreasing caliber is only advantageous to a point, beyond that it becomes counter productive.



It goes back to the original argument about the effectiveness of overmatch. Overmatch is very crucial, until you reach a certain energy threshold, at which point it becomes irrelevent due to ablation taking place. Likewise, lengthening and narrowing the penetrator is advantageous only until you hit the peak of the curve.

...you gave a 5:1 ratio before having to use fins, which may or may not be correct...

I assure you this is factual, I have the book at home if you would like confirmation.








@ Matanga: Keep in mind that tanks are actually older than you think. They have been in RO since mod version 3.0. They were very simplistic, but the penetration model has been identical for a couple years now. The tanks seems to have advanced the most in how they look, e.g. optics, interior areas, etc. They have also been flesched out with co-axials and better reloading.

But, the overall penetration system has not really changed, at least from my perspective. The same critical areas exist from the mod, and the same "3 non-critical hits to blow up" health system.

 

[Sgt.Rock]

I agree with what your saying about the wieght issue, and that there is some sort of curve to it. It would make sense for 88mm round made out of steel (its the lighter one) to have less performance than an 88mm round made out of tungsten (heavier), if their velocities are the same.

Heres an example of a balance between velocity and wieght (the reason for wieght and not caliber is its implied that the larger caliber, the greater the wieght).

These are the 100m penetration values for the Panther, Tiger, and Tiger 2

Panther:

____Range_100m

Angle

0_______176(mm)__________925 m/sec APCBC

30______134

60______62


Tiger:

____Range_100m

Angle

0_______154(mm)__________773 m/sec APCBC

30______120

60______61


Tiger 2:

____Range_100m

Angle

0_______228(mm)__________1018 m/sec APCBC

30______173

60______77


You can see that the Panther beats out the Tiger by having a greater velocity (the diameter might have helped in this case too), even though the round itself is lighter (which I would guess is that its able to put more kinetic energy into a point, through the combined effort of its mass, velocity, and diameter, than that of the Tigers 88mm). But now take a look at the Tiger 2, it has a heavier round and an even greater velocity, so even though the round itself is broader, it puts more kinetic energy onto the target.

One of the issues as rounds get broader is there is more surface area for the round to penetrate. This is one of the problems with tungsten APFSDS rounds, they like to mushroom up during penetration, decreasing their performance because as they penetrate, they constantly have to penetrate more and more surface area.

So all that means that essentially Im agreeing with you in that there is a balance between mass, velocity, length, and diameter when calculating penetration.


Now onto the Modern rounds. Now you said that "This is just one more reason why reducing caliber is not necessarily better, and indeed, may prove counter productive if the shot becomes too long."

Now this is true if both rounds stay the same length, and keep the same velocity, because one round is going to have more mass and a smaller diameter (smaller point of pressure) is not going to make up for it.

But, and this is a big but , that is why designers lengthen rounds. By lengthening the round, your increasing the mass while keeping a smaller diameter. So now you have the mass of a larger caliber round, the diameter of a smaller caliber round, as well as a greater velocity than both (more momentum, greater aerodynamics). This is why modern APFSDS rounds are the way they are, its a win-win situation.

Before I move on though, I'll explain why more length to erode is better. As a penetrator erodes, it loses mass and kinetic energy. So by having more length to erode, it keeps its mass and kinetic energy longer, meaning it can penetrate for a longer time before stopping. About the time it takes for the penetrator to enter the crew compartent, I believe that the whole penetrator doesnt need to be completely inside before devastating effects occur. As soon as the penetrator starts to enter the compartment, it sprays molten spall into the inside of the compartment. Unlike WW2, where AP rounds would "bounce" around on the inside of a tank once it penetrated, modern APFSDS rounds have the possibility of shooting straight through an armored vehicle. If you read the part about the "silver bullet" in my last post, youll see what I mean. So all effects come from spall, and the pentrator hitting anything on its straight line through the target. So now it has to hit personall exactly or go straight through ammunition and the like.

Now you said that "Lengthening the penetrator while decreasing caliber is only advantageous to a point, beyond that it becomes counter productive." Now your right to a certain extent. As we've discussed before, everything is a balance. So yes, once you get so small and long, things start to get weak and have a tendency to bend or break. So designers try to find a balance between length and diameter. At the same time, theyre looking for new alloys, new materials.

I would like to point out though that designers dont just make the diameter smaller to make the point of pressure smaller (thats why penetrators have pencil shaped points, and thats also why DU's adaibatic failure/shear is so beneficial), but they do it mostly to decrease weight to keep velocity. An Ideal situation would be to have a decent diamter, but countinually increase the length of the penetrator while maintaining velocity.

So once you reach an optimum l/d ratio, or even an optimum diameter, the only way to go is to lengthen, so now your increasing mass. To counter-act the loss of velocity incured (since were at an optimum, we cant make the diameter any smaller), designers have to boost the performance of other factors. By lightening the Sabot petals, you increase the initial velocity. By designing better propellents, you can increase the velocity even more. The US did both of those last aspects with their M829A2 round. The M829A2 is marginally heavier than the M829A1, and with the lighter Sabot and better propellent, it has a greater velocity, meaning better overall performance.


So yes, you can only get smaller and longer before you have to keep a certain diameter then legthen (thearby increasing mass) and increase the performance and quality of other factors.





P.S. I didnt mean to question you with that 5:1 ratio thing, I just really didnt know, Sorry.

 

[Nebfer]

^^^ WHAT talk about BS!!

Penetration Data for the 76.2mm F-34 L / 42
(All data is displayed vs. RHA / FHA plate @ 30

 

[Sichartshofen]

Panther:

____Range_100m

Angle

60______62


Tiger:

____Range_100m

Angle

60______61


Tiger 2:

Angle

____Range_100m

60______77

Where did this data come from?

 

[Sgt.Rock]

Where did this data come from?

I got it from CMBB, why? Is there something inaccurate about it? What are you figures for penetration of the three different guns (L/70, L/56, L/71) at 100m for 60 degrees?

 

[[TW]Wilsonam]

I got it from CMBB, why? Is there something inaccurate about it? What are you figures for penetration of the three different guns (L/70, L/56, L/71) at 100m for 60 degrees?

He may be asking because the figures for penetration at 0 degrees appear to be over-stated, compared to German, Soviet, British AND American test figures for those guns ! Actually, I've only checked the first two, too lazy to check the Tiger II

 

[Matanga]

@ Matanga: Keep in mind that tanks are actually older than you think. They have been in RO since mod version 3.0. They were very simplistic, but the penetration model has been identical for a couple years now. The tanks seems to have advanced the most in how they look, e.g. optics, interior areas, etc. They have also been flesched out with co-axials and better reloading.

But, the overall penetration system has not really changed, at least from my perspective. The same critical areas exist from the mod, and the same "3 non-critical hits to blow up" health system.

Maybe we see thing in a different way.

In my opinion (and keep in mind I haven't played the mod) the Tank Combat model has/(should have) 2 parts.

1 - Penetration : That will tell us if the round went in or not. Which is I see you guys are disscusing here. That has to be a non-deterministic model that uses historical data as constants (armor thickness, proyectile mass,etc). And I say non-deterministic because that's the best way to model reality.

2 - Damage : This one should tell us what happens when the round goes in. This is a hard one as it could use as many factors as you choose : Hit location, round velocity, round mass, angle, it could even use data provided by the Penetration Calculations (depending on how it is modelled)

These models can be as complex or as simple as you want (sometimes the simplests ones are the best).

Personally I'd love to see, not only, proper penetration calculations but also a realistic damage model. Where tank crew can get killed or stunt, things stop working (tracks,the main gun,engine,coaxial guns,etc).
Specially since that will force players to abandond the tank and not just the "die - respawn - get into tank - go back to battle" that it is now.

But I'm well aware that this is hard to achieve...

 

[Rameusb5]

OK, I tested the Tiger vs the Soviet SU76 last night (there's NO official map that has the Tiger and the T34/76). From about 50-100 meters i was completely unable to destroy the Tiger in one shot. I did notice that if you aim for the Tiger's left track (the one on the right if you are facing the Tiger), you ALWAYS get an engine damage (any type of ammo). That was the only repeatable way to inflict ANY damage to the Tiger frontally. Further shots to that area did not seem to have any effect. I was unable to actually "track" the Tiger while shooting at the tracks (with any type of ammo).

I did check HE as well as AP. HE was able to eventually destroy the Tiger frontally, but the number of shots to do this seemed very random. It ALWAYS required a large number of HE shots to completely destroy the tank.


At least for the gun on the SU76 (which is not the same gun on the T34/76, but they are similar in penetration abilities), there is no repeatable way to destroy the Tiger in one shot frontally. At least that I could find. You might be able to EVENTUALLY get a kill, but there was NO spot that I could find that guaranteed a quick kill with either type of ammunition.

 

[Solo4114]

OK, I tested the Tiger vs the Soviet SU76 last night (there's NO official map that has the Tiger and the T34/76). From about 50-100 meters i was completely unable to destroy the Tiger in one shot. I did notice that if you aim for the Tiger's left track (the one on the right if you are facing the Tiger), you ALWAYS get an engine damage (any type of ammo). That was the only repeatable way to inflict ANY damage to the Tiger frontally. Further shots to that area did not seem to have any effect. I was unable to actually "track" the Tiger while shooting at the tracks (with any type of ammo).

I did check HE as well as AP. HE was able to eventually destroy the Tiger frontally, but the number of shots to do this seemed very random. It ALWAYS required a large number of HE shots to completely destroy the tank.


At least for the gun on the SU76 (which is not the same gun on the T34/76, but they are similar in penetration abilities), there is no repeatable way to destroy the Tiger in one shot frontally. At least that I could find. You might be able to EVENTUALLY get a kill, but there was NO spot that I could find that guaranteed a quick kill with either type of ammunition.

Based on my own anecdotal experiences, I'd have to agree. I think the 76mm guns can't PENETRATE the Tiger's frontal armor, but they can still DAMAGE the frontal armor to the point where you can kill at Tiger in 2-4 shots or so (maybe 3-5) due to the cumulative damage system. This is part of my gripe about the cumulative damage system. While it models some aspects of gameplay (IE: a penetrating shot that doesn't actually hit anything vital), it's also not entirely clear that it isn't ALSO modelling the overall weakening of armor at that position.

I suppose it's the difference between "Hull damaged" and "destroyed" in a game of Steel Panthers, for example. In the one case, you don't destroy the tank and may not even cause the crew to bail. In the other, well, duh. Tank = dead.

I think this highlights the need for a different approach to tank penetration that still uses the same overall system. In essence, a shot that doesn't penetrate and doesn't damage any subcomponents basically is treated as having done nothing (since we're not modeling spalling or a concussed crew). For penetrating shots, we need a crew compartment. If you penetrate it, you kill the tank basically.

Adding this as well as a turret traverse, optics, and possibly gun elevation controls would really help in terms of providing a more robust tanking experience. Plus, it'd give the PTRD guys something to do -- shoot a weak spot (optics, viewslots, turret turning mechanism) and you can cripple the tank, though you can't kill it.

 

[ViViD]

Cumulative damage on tank combat is a crock, it is the weakess part of RO and turn what could be a great tank sim into a cheezy video game.

 

[Aelius]

OK, I tested the Tiger vs the Soviet SU76 last night (there's NO official map that has the Tiger and the T34/76). From about 50-100 meters i was completely unable to destroy the Tiger in one shot. I did notice that if you aim for the Tiger's left track (the one on the right if you are facing the Tiger), you ALWAYS get an engine damage (any type of ammo). That was the only repeatable way to inflict ANY damage to the Tiger frontally. Further shots to that area did not seem to have any effect. I was unable to actually "track" the Tiger while shooting at the tracks (with any type of ammo).

I did check HE as well as AP. HE was able to eventually destroy the Tiger frontally, but the number of shots to do this seemed very random. It ALWAYS required a large number of HE shots to completely destroy the tank.


At least for the gun on the SU76 (which is not the same gun on the T34/76, but they are similar in penetration abilities), there is no repeatable way to destroy the Tiger in one shot frontally. At least that I could find. You might be able to EVENTUALLY get a kill, but there was NO spot that I could find that guaranteed a quick kill with either type of ammunition.

Don't do tests at 100m or below. There is a know issue with wierd things happening with penetration at ranges like that.

I would try tests from 200m, 500m, 800m, 1000m. You will get some odd but far more accurate results. Some rounds fired and landing near the Tiger will commonly damage the engine without ever touching it (has happened to me in a Stug as well). I have had my Tiger's engine destroyed by an SU76 with a direct frontal hit from roughly 800m but that only happend once from that distance. It has happend the other day from about 50m vs a different tank (KV1?). Again wierd things happen at close ranges like that.

And yes I actually had my Tiger blow up twice from side rounds fired at it and get one shot kills under 100m. From the rear the Tiger is a paper toy vs a 76m gun and virtually garantees a kill in, if not one, two rounds.

 

[Rameusb5]

Don't do tests at 100m or below. There is a know issue with wierd things happening with penetration at ranges like that.

The problem with doing the test at greater ranges is that it's difficult to know exactly what part of the tank I'm hitting, since the optics don't magnify that much. I initially started my test at ~100m but had to close because I couldn't tell exactly WHERE on the Tiger the rounds were landing. None of the rounds I fired from that range were one-shot kills though...

And yes I actually had my Tiger blow up twice from side rounds fired at it and get one shot kills under 100m. From the rear the Tiger is a paper toy vs a 76m gun and virtually garantees a kill in, if not one, two rounds.

According to this site. The Soviet 76mm gun on the T34 is capable of penetrating over 80mm of armor at 0 degrees. Which makes what you are describing incredibly possible (realistically).

That being said, when I did my test of the Su76 against the Tiger's side armor, it ALWAYS took exactly 3 rounds to kill the Tiger. Of course, the Su76's gun is weaker (in penetration) than the F-34 gun found on the T-34. I'll have to load Orel up on my custom maps and have a look (since it's the ONLY map that has both a T34/76 and a Tiger).

 

[Mike_Nomad]

Simply put;

Armor and projectile penetration characteristics along with turret rotation speed needs help and of course, the ready racks are in desperate need.



Reload speed is a problem not only for the tiger... but for a number of other tanks (Russian).