Steve (BTS): ROF of ISU-152

[Commissar]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

Skipper:

"Steve did say 1.5 shots per minute, not one shot per 1.5 minuets"

Yup, that is what I said

Depends on the source, the standards used, and the context of the 1.5 rate I used.

As for sources, Charles found a very respected source (Valera's site I think. Don't have URL handy) which put the rate at about ONE round per minute. We also found the rate listed as 2 and 3 rounds per minute. Our own assessment is that it is somewhere down at the lower end due to the crew, gun, and ammo storage realities of the ISU-152.

As for standards used... there are many. The most commonly found one in sources is "test range", which is the upper range. It is likely to be higher than what even a battle hardened (but not exceptionally talented) crew could manage. The second most common one is a practical rate of fire. Unfortunately, neither of these are very often defined well so it is pretty much a guessing game as to what the different crews could manage.

Unless I state otherwise, I always discuss things in terms of Regular experienced units in more or less common combat condtions. Thus, a Regular ISU-152 crew could probably do about 1.5 rounds per minute, while an Elite crew might crack off slightly more than 2 rounds per minute. I don't know the exact figures we will use because we haven't cast them into stone yet

The short of it is... there ain't a lot of difference between 1.5 and 2 rounds per minute. Both suck if the target is capable of motion. Even 3 rounds per minute is pretty horrible. But as someone said, the ISU-152 was not designed to be a tank killer, but rather a fortress killer. It was the ultimate outgrowth of lessons learned during the Winter War where the Soviets lacked a heavy howitzer assault vehicle. The KV-2 was supposed to be the answer to this problem, but it wasn't a very good tank design.

So even though the ISU-152 has a terrible RoF, it is still a vehicle to be feared. Especially if it is allowed to roam around the battlefield blowing up fixed fortifications. I can think of no other Soviet vehicle I would liked to have seen less if I had been an Axis soldier!

Steve<HR></BLOCKQUOTE>

Shhhh!!! The Prophet speaks!! Pay homage and let's see how long this thread can be prolonged.

[Skipper]

Brr... looks like I mixed 122 and 152 mm in this thread a couple of times. Silly...

However, another guy said that training standard for ISU-152 was 2 shots in one minute. "Training standard" means a parameter that a regular crew was expected to exceed.

As a matter of fact, in my days training for a radiooperator, there were three training standards - "satisfactory", "good" and "excellent". I don't know which mark that guy was talking about, probably "excellent".

In my own case, it took people 2 to 4 months of training to get "excellent" marks (iirc, 100 morse symbols per minute on receipt). Anybody could do that, if he wanted. I, for one, have eventually exceeded that standard by 60% margin - 2nd best result in the school. And that was the pace all professional radio operators I knew, those who did it for living, could do.

[ 06-07-2001: Message edited by: Skipper ]

[Jeff Heidman]

"Training standards" are always in relation to a training environment.

As an infantryman, I was expected to be able to hit 30 out of 40 targets at ranges from 25-300m. That made me meet the "standard".

I fired expert, which meant that I could hit 36 out of 40 targets. Good for me.

Does that mean that I expect to hit those same 36 out of 40 targets in combat? Even if they acted just like the pop-up targets on the Ft. Benning rifle range? Of course not. Does it mean I could even hit the minimum standard of 30 out 40? Not a chance.

It does mean I have a basic understanding of how to use my rifle. It means that my instructors can conlude that I at least understand the theory of how to engage targets. Not much more than that, and certainly no conclusion could be drawn about how many I could actually hit in combat.

How many times have we seen this example of people citing "training" results as evidence that something is broken in CM, or some proposal is incorrect?

Jeff Heidman

[Jeff Heidman]

Another point: If we are going to use these "training standards" as data to determine the ROF for the SU-152, then I think we need to do the same for every other vehicle in the game.

Jeff Heidman

[Skipper]

Jeff,

Shooting accuracy is one thing (concentration and calm of mind), rate of fire is quite another (moving quickly with force).

I have no combat experience, but I do have some experience of fast, life threatening situations (6th grade white water rafting). Believe me, things were done faster than in training. However, when I was once going with the flow towards 6 meter high vertical waterfall, I do remember that safety line throwing accuracy was NOT to my liking in a big way

Aint know if it is really relevant to combat, though.

> Then I think we need to do the same for

> every other vehicle in the game.

Well, I dont say it is not so for the ROF. Maybe, it is.

[Jeff Heidman]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Skipper:

Jeff,

Shooting accuracy is one thing (concentration and calm of mind), rate of fire is quite another (moving quickly with force).

<HR></BLOCKQUOTE>

Uhh, last I checked shooting was a part of ROF.

You do have to aim the gun prior to firing, don't you?

My analogy still holds. That "training standard" I alluded to had a time limit, hence my ROF was also being tested.

My analogy still holds. That "training standard" I alluded to had a time limit, hence my ROF was also being tested.

In fact, the arguments about how long it takes to laod the shell are like me arguing that I should be able to engage 30 targets with my M-16 in just a few seconds, since that is how long it takes the weapon to cycle through a magazine.

The loading time is irrelevant if it is not the limiting factor, and I am betting getting the gun laid on target and adjusted for range is the limiting factor.

Jeff Heidman

[ 06-07-2001: Message edited by: Jeff Heidman ]

[Skipper]

> The loading time is irrelevant if it is

> not the limiting factor, and I am betting

> getting the gun laid on target and

> adjusted for range is the limiting factor.

With one shot in 30 seconds, I'd imagine that it is not so for all shots at the same target except the first one.

ROF we are discussing for the ISU-152 is limited by loading and rollback (whatever is the english term for returning the gun to ready state after a shot) times.

[Username]

Are vehicles in CM2 going to have generic percentage placement of hits against them or vehicle specific percetage-to-area?

Against oddly shaped vehicles like the 152 this would be important. As I said, the vehicle seems vulnerable in areas.

Lewis

[Mr. Johnson--]

Are you guys trying to crash the forums again?

[Skipper]

hehe... so it seems

[Battlefront.com]

Skipper,

As Jeff has stated, training "standards" are not relevant to battlefield results. At least not 1:1. This isn't just Jeff and me talking here, but established fact. Training standards are just that -> TRAINING standards. They are not COMBAT standards. If they were, it would have taken a couple hundred shots to kill one man in combat. So any arguments that we should base our figures on training numbers is absolutely going to be rejected by us. 100% of the time, all the time

What training standards ARE very good for is establishing a ball park estimate for what could in theory be done under peacefull conditions by a well trained crew. Contrary to your understanding, "Regular" experience in Combat Mission represents average trained, modestly battle tested troops. This would be the low end, or what you described as "satisfactory". "Good" or "Excellent" would are not what the average soldier acheives, especially not after hurried basic training.

Jeff also wrote:

<BLOCKQUOTE>quote:</font><HR>Another point: If we are going to use these "training standards" as data to determine the ROF for the SU-152, then I think we need to do the same for every other vehicle in the game.<HR></BLOCKQUOTE>

Absolutely correct. The standards in CM are based on "combat standards". If we just went and plugged in ONE "training standard" number we would have to do that for every weapon in the game, adjust shot:hit ratios, and lower morale penalties. Not going to happen

Lewis:

<BLOCKQUOTE>quote:</font><HR>Are vehicles in CM2 going to have generic percentage placement of hits against them or vehicle specific percetage-to-area?<HR></BLOCKQUOTE>

Same modeling as with CM1. Until we rewrite the game engine, which will do far more than just this, we can't do much to change the basic way the modeling works.

<BLOCKQUOTE>quote:</font><HR>Against oddly shaped vehicles like the 152 this would be important. As I said, the vehicle seems vulnerable in areas.<HR></BLOCKQUOTE>

No more so than with current vehicles IMHO. We have the "lucky shot" thing in CM1 now and that will apply to CM2 as well. However, we are going to code up something that allows underclassed AT weapons, in given situations, to have a better chance of hitting a vulnerable spot such as the tracks. This was about all the 37mm AT gun was good for vs. Soviet armor Its high rate of fire and accuracy enabled it to still cause problems until early 1942 if the situation was right.

Steve

[Mr. Johnson--]

Is the door knocker going to cause increased chances of killing the driver of enemy tanks?

Ie. Shooting at the driver vision slot? As they were trained to do?

[JasonC]

"we are going to code up something that allows underclassed AT weapons, in given situations, to have a better chance of hitting a vulnerable spot such as the tracks"

That would be great. Certain westerners would like it too - LOL.

[Triumvir]

Don't forget the turret rings!

As for returning to battery position, any modern recoil system returns to battery almost immediately upon the round having left the barrel. As for realignment... depends on the loader.

I'm sure that the ISU-152 could handle up an RPM of 3-4 rounds if it was used as SP artillery, firing indirect. I've been on a 155 gun crew that could do 6-7 rounds a minute (admittedly, with 1 round in the chamber, 1 in the rammer and one in the loader's hands.)

But as for direct fire, I'd think that mere loading is not as important as the aiming and firing. I remember that the direct aiming sights we used were remarkably user unfriendly; but then again, we never expected to use them.

[Matthew_Ridgeway]

The history of battle, a commander's experience, and the wisdom of military philosophers all confirm the direct correlation between training and victory in war. Successful combat units train as they intend to fight and fight as they were trained. Competent Modern Armies base their future success on the battlefield on this philosophy. The battle is the ultimate test of training. To train as you will fight is the fundamental principle upon which most armies base their training methods.

[Amedeo]

Just to boost this amazing thread with another ISU related issue:

what do you think should be the appropriate blast factors for the Soviet 122mm and 152mm rounds?

Amedeo

[Stalin's Organ]

Probably much the same as other 150mm, but the 122 will be a bit better than the 105's or 4.5's...not quite as good as the 5.5

[PzKpfw 1]

Some Soviet Data on ROF for their Artillery pieces, which most of the Soviet AT & Tank guns were developed from below are a few 122mm & 152mm examples:

122mm M109/37 Howizter

Weight of shell - 21.76 kg (HE)

ROF - 5 - 6rpm.

122mm M1910/30 Howitzer

Weight of shell - 21.76 kg (HE)

ROF - 5 - 6rpm.

122mm M1938 M-30 Howitzer

Weight of shell - 21.76 kg (HE)

ROF - 5 - 6rpm.

122mm M1931 (A-19) Cannon

Weight of shell - 25.00 kg (HE)

ROF - 3 - 6rpm.

122mm M1931/37 (A-19) Cannon

Weight of shell - 25.00 kg (HE)

ROF - 3 - 6rpm.

152mm M1909/30 Howitzer

Weight of shell - 40.00 kg (HE)

ROF - 2 - 5rpm.

152mm M1910/37 Howitzer

Weight of shell - 40.00 kg (HE)

ROF - 2 - 5rpm.

152mm M1938 M-10 Howitzer

Weight of shell - 40.00 kg (HE)

ROF - 2 - 5rpm.

152mm M1943 D-1 Howitzer

Weight of shell - 40.00 kg (HE)

ROF - 2 - 5rpm.

152mm M1910/30 Cannon

Weight of shell - 43.56 kg (HE)

ROF - 2 - 5rpm.

152mm M1910/34 Cannon

Weight of shell - 43.56 kg (HE)

ROF - 2 - 5rpm.

152mm M1937 Gun/Howitzer

Weight of shell - 43.56 kg (HE)

ROF - 2 - 5rpm.

152mm M1935 BR-2 Cannon

Weight of shell - 43.56 kg (HE)

ROF - 1 - 2rpm.

Regards, John Waters

[ 06-09-2001: Message edited by: PzKpfw 1 ]

[JasonC]

I'd expect the blast factors for the 122 and 152 to be comparable to those for the 4.5" gun and 150-155mm howitzers in CM, respectively. Thus, on the order of 125 and 200 blast. The Russians would also use a lot of 82mm mortar, 76mm off-map artillery, and 120mm mortars.

Or -

82mm - 19 fast response and high ammo

76mm - 35 high ammo

120mm - 80 fast response, moderate ammo

122mm - 125 moderate ammo

152mm - 200 low ammo

And of course the rockets in various calibers, too. But those would be the big ones. Notice that the 120mm mortars would fufill much of the lighter work done by 25 lbers and 105s for the western allies, while the 122mm would do some of their heavier work with bigger shells, but somewhat fewer of them.

[ 06-09-2001: Message edited by: JasonC ]

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>John Said: Some Soviet Data on ROF for their Artillery pieces, which most of the Soviet AT & Tank guns were developed from below are a few 122mm & 152mm examples:<HR></BLOCKQUOTE>

Yes but were those ROF's developed from "training standards" or "combat standards" cause we all know there was a BIG difference between the two

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Yes but were those ROF's developed from "training standards" or "combat standards" cause we all know there was a BIG difference between the two <HR></BLOCKQUOTE>

Jeff the data is not diferentiated the ROF is what the guns are 'capable of' per minute & thats the only explanation given other then shell weight, artillery piece weight and maximum range.

Regards, John Waters

[Dittohead]

One note on the IS-2 It only carried 12 rds in the ready rack with the rest in the hull in metal cases. With no turret basket and with two piece ammo, should the IS-2 suffer a ROF penalty after it fires 12 rds or should it be spread out among all rds?

[JasonC]

The IS-2 certainly stowed rounds in the back of the turret. Not under the floor. The ISU-152 had all 20 rounds in the ready racks, but only ~12 of the -powder- charges in them, and the rest in the floor. But those are considerably lighter to fetch out (though still not fun in action, obviously).

[Dittohead]

I got the info on the IS-2's From Stalin's Heavy Tanks 1941-1945 - Zaloga, Kinnear, Aksenov & Koshchavtsev - pg 44 "The Reserve ammunition for the gun was kept in metal containers on the floor" "The ready ammunition for the IS-2 was kept in the rear right hand side of the turret bustle behind the loader." pg 45. "The floor is made up of metal ammuntion lockers for the reserve supply ammunition supply."

From the pics I would say that there appears to be at least 8 cases on the floor. And it clearly shows the 12 spots for the ammo and propellant in the turret. Not much room in the turret for anything else. Plus the turret looks like it will block access to some of the cases depending on which way it is facing.

[PzKpfw 1]

IS-2 ammo was stored in 2 parts in floor racks & the turret bustle. The 2 part ammo was another reason for the slow ROF, but as the IS-2 was meant to deal with German fortifications, & be frontaly immune to the standard German AT gun, the7.5 cm PAK.40

ROF realy wasnt an issue vs bunkers & fixed AT positions, except in ammunition limitations, as it would be if the task was tank vs tank fighting. Another aspect concerning the IS-2, is they only carried 5 - 7 AP-T rounds, out of the 28 main gun round's the main loadout was OF (HE) rounds for the above reasons.

Regards, John Waters

[ 06-09-2001: Message edited by: PzKpfw 1 ]