Steve (BTS): ROF of ISU-152

[Dittohead]

Don't forget IS-2's only carried 28 rds of which no more than 14 were AP. Maybe the German's mistook the IS-2's going back to resupply as running away. After any type of tank engagement or battle the IS-2 would have to resupply. Usually the tiger's would show up for the counter attack so it would make sense that the IS-2's might not engage Tigers without a full loadout of ammo.

[Skipper]

iirc, normal AP loadout for an IS was something like 8 out of 28.

[Andrew H.]

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

. Maybe the German's mistook the IS-2's going back to resupply as running away. <HR></BLOCKQUOTE>

It's also possible that "running away" (a term that has negative connotations) is absolutely the correct tactical move for IS-2s in many situations. Given the relative rarity of Tigers overall, it would make a lot of sense for IS-2s to avoid a direct confrontation with the Tigers and either try for a flank shot or, on the attack, ignore the Tigers and attack a less well-defended area. If the Tigers are on the attack, retreating and allowing AT guns to hit the Tigers makes a lot of sense, too. Certainly engaging Tigers at a range that would result in the loss of the IS-2s with minimal losses to the Tigers makes less sense than "running away."

[Amedeo]

Owing to the scarce normal loadout of AP ammo (IIRC 10 out of 28 rounds) for the IS-2 tank, I presume that the engagements against German heavies at 2000m or so were made with 'platoon fire' i.e. the tanks in a company fires alternatively passing range information to each other. I know that this was done by Tigers for extreme ranges out to 3000m (or at least the regulations called for this) just wondering whether it was the same for the Soviets.

Amedeo

[Commissar]

Another factor might also be that German Tiger crews had much better optics and training and had a better change of hitting Soviet tanks from long range than Soviet crews had at hitting German tanks at long range.

From what I understand, the IS-2's main role wasn't to engage tanks but infantry and AT-guns (hence the reason why they carried more HE rounds than AP). Of course, IS-2s can engage other tanks and generally hold their own quite well (including against the dreaded Tiger).

On ASL Vet's Panzertruppen quote, as one poster already mentioned I wonder about whether these German crews correctly identified the tanks they knocked out. Apparently it is not uncommon to mistakenly identify vehicles (ex: Americans and their many mis-ids of regular panzers for Tigers, Russian mis-ids of StuGs as Ferdinands, Germans of various soviet tanks for IS????). Also there were two types of IS tanks, the IS-1 with the 85mm and the IS-2 with the 122mm. IS-1 apparently did not perform so well unlike its brother, the IS-2. Other than the gun, both the IS-1 and IS-2 had the same turret, chassis, hull, etc at least early on. It wouldn't be hard to misidentify an IS-1 for an IS-2 especially at a long distance. Also the Panzertruppen report doesn't seem to state what type of IS tank was knocked out. Anyway, BTS seems to hint that the IS-2 will be a monster to take on in the game.

[ 06-06-2001: Message edited by: Commissar ]

[Vanir Ausf B]

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

I believe that Steve's remark about the Elephants abilities and the SU's atributes started this.<HR></BLOCKQUOTE>

The funny thing is that it was actually a misunderstanding of what Steve said that started this. I went back and looked and Steve did say 1.5 shots per minute, not one shot per 1.5 minuets as the original poster thought.

Good discussion anyway

[ 06-06-2001: Message edited by: Vanir Ausf B ]

[Skipper]

> Steve did say 1.5 shots per minute, not

> one shot per 1.5 minuets

Either way, 152mm SPGs (as opposed to tanks) could fire twice as rapidly.

[dNorwood]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Vanir Ausf B:

not one shot per 1.5 minuets

[ 06-06-2001: Message edited by: Vanir Ausf B ]<HR></BLOCKQUOTE>

Kinda depends on how fast you dance....

[JasonC]

First to Michael, my comment about "light work" referred to the rest of the sequence of tasks the loader goes through to operate the M-109, besides actually putting in the shell.

That includes #1 ramming the shell forward until seated properly in the tube, which in the M-109 is done hydraulically, with a telescoping "press" that swings down from the ceiling. Then #2 placing the powder in behind the shell. The #3 closing the breech, which is mostly accomplished by a spring-release, and finished off with a long vertical lever on the right side of the breech, that rotates the heavy breech block only the last few inches, smoothly. Then #4 priming the "touchhole" with a cartridge that detonates the powder, and sliding the touchhole mechanism closed. Then #5 attaching a lanyard to a loophole on the priming mechanism, and last #6 on order, smoothly pulling the lanyard.

All of them are done rapidly and do tax agility and presence of mind, but none involve significant physical labor, in the sense of applying major effort with major muscle groups. The point was about cumulative fatigue on loaders. While doing all those things, the major muscles are effectively resting, much like walking around between repetitions when weight-lifting. By the time the next shell lift occurs, there has been perhaps 10 seconds of such "light" work. The point is that loaders are not engaged in lifting 100 lb shells continually over minutes or tens of minutes, which would indeed be tiring. The periodic heavy lifts, I said directly, do give you a decent work-out, just like weight reps do. But because these lifts are interspersed with lighter work, the whole effect is not all that tiring, over a period of 20-30 minutes (as I mentioned), or over the number of shells in typical fire missions or even carried on one gun.

As for traveling, we generally sat on the floor with our backs up against the side of the vehicle, and the legs out in front into the middle. The arms are spread front and back to brace oneself, on the wall or the floor or both. One moves around a bit to prevent cramping up, of course, and going over terrain one sways certainly. We'd never try to fire an M-109 while it was moving, except the shell already loaded perhaps, at something so close and big it would be hard to miss (like the proverbial broad side of a barn).

The army regs call for being able to conduct a battery-size hip shoot, fully "laid" to fire on coordinates only, within 2 minutes of reaching a position. But getting this time down to a minimum was one of the primary focuses of training, and my unit often managed to do so within 45 seconds, which was not particularly good by active-duty unit standards incidentally. This includes the "surveying" work of locating the howitzer and horizon points of aim (to let the FDC plot its position accurately by map triangulation - probably simply these days with GPS by the way), setting its sight compasses, dropping spades at the rear to anchor vs. the recoil, prepping a shell, etc.

(The other time periods focused on in training were delivery of a certain size fire mission from order to last impact, and getting onto the road in "march order" to leave a battery position - something essential to do very fast in this era of counter-battery radars).

All that is in the M-109 of course. In the ISU-152, the loader and assistant loader each had bench seats along the walls, left and right respectively. The loader side has a bit less room, because he is essentially sitting with his back leaning up against the ammo racks. The assistant is on the side of the gun with less room between breech and wall, but has a longer seating area. He would be less comfortable when the gun was parked and firing, more so when traveling, than the 1st loader.

The IS-2 is different again. That has only one loader seated on the right side of the gun in the hull compartment, while the commander up in his turret seat is farther back. This would be easily for traveling - a seat facing the direction of motion always is - but his loading task would be somewhat harder. He had a few ready-rounds on small racks just to his right, but most of the shells were at the rear of the turret, and he would have to turn around and lower them down, etc. His seat could be folded out of the way while in action if desired, to have more room to stand and turn. In position, I bet it was most of the time, simply because one might trip over it when turning back around with a shell from the rear of the turret otherwise. So I bet the seat was only "up" for moving, or engagements of 4 shells or less (about), where the one in the tube and the few on the right would suffice. Longer positional shooting they'd probably get it out of the way to fire faster - perhaps losing a shot or two to make the switch, incidentally, after about the 4th round.

As for ASL's document about engaging IS-2s, every aspect of it made sense to me and I find it very believable. The IS-2s backed number one up because Tigers had guns that could kill them from the front from close range, so they tried to open the range. The comment about only being willing to engage at 2 km, and then only from favorable cover, strikes me as simply sound tactics. The closer you are, the easier others find it to get flank shots, and close enough Tigers start getting front penetrations too. Whereas the 122 would penetrate 100mm boxy armor at long range if a hit was obtained. It doesn't matter too much if the hits get harder to obtain, if his don't kill you while yours do kill him.

The points about coordination of the Tigers and use of platoon tactics, avoiding single commitment, also make obvious sense. With two Tigers standing off any appreciable distance from one another side to side, no IS-2 could afford to close. It would just give one of the pair a flank shot if it did. But a single Tiger this would no longer be true, and medium ranges (well more than 500m, probably 1km or more, but less than 2km), front aspect, easier hits at those ranges etc, would all favor the IS-2.

I also agree with another fellow's comment that the best use of IS-2s was certainly not tank-dueling with German heavies. They wanted to hit where only German PAK or lighter StuGs and Marders, etc, were present to oppose them. As another (here I think) has put it, strategy is the art of avoiding a fair fight. The place an attacker wants his ~20 IS-2s is where there -aren't- sufficient heavy AT weapons to oppose them, not where there are some.

[JasonC]

To Triumvir -

At one time or another I checked out on every task on the M-109 and M-110 except driving the beasties. I also did special weapons detail for the M-110, which was mostly about security procedures (as in, don't let any of the wrong people anywhere near the 8" gas rounds, which incidentally we never had and I never saw LOL).

[ASL Veteran]

Here are more tidbits from “Panzertruppen Vol 2” – a very good reference BTW (along with Vol 1 if you have the cash):

<BLOCKQUOTE>quote:</font><HR> Extracts from a translated Russian pamphlet entitled ‘Russian tank tactics’ were included in the following article describing recent experience in Panzer combat on the Eastern Front published in the August 1944 issue of the Nachrichtenblatt der Panzertruppen:

The following quotations are from a translation of the Russian pamphlet entitled: “Russian Tank Tactics”:

The importance of the tank units is related in the introduction. The conclusion from experience in previous battles is that tank versus tank battles are unavoidable. The editor – a lieutenant colonel in command of a tank unit – emphasized that whenever possible the tanks of the enemy were to be destroyed as soon as possible by the air force, artillery, and anti tank weapons, so that our tanks remained free to attack enemy infantry.

In his further discourse on tank battles he states:

“The commander must always cold bloodedly and methodically consider which is more favorable: To immediately attack an enemy tank unit or to take up a defensive battle firing from stationary tanks. In the first case, he can suffer large losses. In the second case, he runs the danger of an enveloping attack resulting in being subjected to concentrated fire.”

“Above all else, a tank battle is a firefight. Even though movement is important, the threat of enveloping the opponent should not necessarily force him to retreat. It is better to exploit the terrain for obtaining cover in order to open well aimed rapid fire from favorable firing positions.”

Our position: The superiority of our Panzers clearly is proven by the intention of the enemy tank units to avoid tank versus tank combat. Our response is that we must seek to engage in tank versus tank actions at every opportunity, the prerequisite being that the destructive effects of the enemy air force and artillery against our units can be avoided so that movement or assembly by day can occur.<HR></BLOCKQUOTE>

Here is another tidbit I found interesting (there is tons of more stuff but I can’t possibly post it all!!)

<BLOCKQUOTE>quote:</font><HR> This last experience report is from the 1st Abteilung/Panzer Regiment 24, which had been outfitted with 60 Panthers and sent to Heeresgruppe Sued on the Eastern Front in January 1945. During the period of this report the Abteilung was attached to one of four Panzer – Divisions, usually the 1st Panzer Division.

The anti tank guns are the main opponent of Panzers in the Eastern Theater of War. The Russians use anti tank guns en masse for defense or by cleverly towing them along behind an attack to swiftly bring them into action. The meaning of “Pakfront” does not totally describe the actual situations experienced in combat by the Abteilung because the opponent employs this weapon more concentrated in so called “Paknest” in an attempt to achieve a long range flanking effect. Sometimes the Paknest consist of 6 to 7 anti tank guns in a circle of only 40 to 50 meters. Because of the excellent camoflauge and use of terrain – sometimes the wheels are taken off to reduce the height – the Russians easily manage to open surprise fire at medium and close range. By allowing the lead vehicle to pass by, they attempt to open fire at our formation in the deep flank.

If the Russian anti tank crews are spotted and taken under well aimed fire, they quickly leave their weapon. However, they quickly reman the guns when not observed or when firing ceases and again take up the firefight.

(huge snip)

The firing range is decisive for fighting with Pakneste that appear beside each other in a row as a Pakfront. If a Panzer formation is fired on surprisingly at short range, all weapons need to be employed immediately. If a Panzer formation encounters a strong anti tank emplacement at long and medium ranges, they should break off the action and attack at a new location. The Panzermann must attempt to continuously utilize the long range of his weapon. However, this requires observation halts in order to spot the anti tank guns in time.

Closely associated with this is the employment of our combat reconnaissance, which moves forward on a wide formation in front of the main body in order to find any Paknest that can be spotted only after they fire. During such a reconnaissance, with elan these Panzers must move at the highest possible speed from observation point to observation point, conduct detailed combat reconnaissance while halted, and cause the enemy to reveal himself by firing at suspicious terrain features. The combat reconnaissance can be thoughtfully and correctly handled only when they move far enough ahead of the main body that they are not pressured from behind. The successful battle with the anti tank guns requires exacting reconnaissance, especially feeling one’s way forward, quick decisions after spotting the target, clear and understandable orders, and swift implementation. In addition, the Panzermann has to suffer under the meager understanding of the Grenadiere commander, who can’t comprehend how the Panzers must fight the enemy anti tank guns.<HR></BLOCKQUOTE>

[Skipper]

> I also agree with another fellow's comment

> that the best use of IS-2s was certainly

> not tank-dueling with German heavies.

Of course not! Late into the war that was a task for 100 mm AT and SPAT guns. Better AP performance, notably better accuracy and much better ROF. It wasnt put into the IS for several reasons, one of them was HE load much lighter than the 122mm.

[Stalin's Organ]

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

Of course not! Late into the war that was a task for 100 mm AT and SPAT guns. Better AP performance, notably better accuracy and much better ROF. It wasnt put into the IS for several reasons, one of them was HE load much lighter than the 122mm.<HR></BLOCKQUOTE>

IIRC the main reason whas that there was plenty of spare capacity for the 122 mm guns, whereas the 100mm had only limited production capacity available. It's AP performance wasn't THAT much better than the 122 to make it worthwhile to delay introduction until it could be produced in numbers.

[Stalin's Organ]

Hey - this thread has more posts than the latest PENG abomination!!

Well done team!!

[Skipper]

That was another reason, but note that IS-3 has the same 122 mm gun, even though this model was produced when 100m gun availability wasn't a problem at all.

[Stalin's Organ]

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

That was another reason, but note that IS-3 has the same 122 mm gun, even though this model was produced when 100m gun availability wasn't a problem at all.<HR></BLOCKQUOTE>

Err....no...the IS-3 was produced in the last months of WW2, and designed in 1944-45 - when production constraints were still a very real consideration.

You might make the point for the IS-4 and subsequent heavies, but by then the 100 was in service in adequate numbers anyway, and there was no need for heavies to mount it at all.

[Simon Fox]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Stalin's Organ:

Hey - this thread has more posts than the latest PENG abomination!!<HR></BLOCKQUOTE>That's rather ironic since you're a contributor to said abomination and doing your level best to make it more so by the look of it. So, on yer bike, mike!

[Stalin's Organ]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Simon Fox:

That's rather ironic since you're a contributor to said abomination and doing your level best to make it more so by the look of it. <HR></BLOCKQUOTE>

And your point is??

Even the age-old (as opopsed to old age) residentsof pengdom are quick to acknowledge the disgusting nature of their habitate - that's part of the attraction

[Commissar]

I don't think the German assertion that Soviet avoidance of tank-to-tank battle is necessarily proof of the superiority of German tanks. It maybe and then maybe not. This may be an objective opinion but could also be German boasting in the face of an increasingly bad operational/strategical situation for the Germans. Perhaps this is just to help bolster morale and confidence. One thing is clear: the Germans still remained tactically flexible and well-skilled and gave the Soviets some nasty surprises even when retreating (when they were allowed to). They performed amazing feats despite the operational and logistical limitations placed upon them. The idea in war is to use one's strength against an enemy's weakness. Butting head-to-head sounds nice but not very efficient and you still have a good chance of losing with heavy losses. If I can sucker enemy tanks into AT traps and eliminate them that way, then that would be the superior strategy to me. Let him come into close range, totally unsuspecting and then blast the crap out of him. This allows my tanks to freely cause havoc among the enemy's softer targets while using AT guns to what they do best.

Again, where in Panzertruppen is this report? I actually own both books (damn bloody expensive but pretty invaluable for learning German armor tactics, production, etc). ASL Vet, if you could please point out the page numbers. It's been a very long time since I've read these books. If anyone can afford the steep price, definitely get these books. They are extremely intereting.

[ASL Veteran]

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

Again, where in Panzertruppen is this report? I actually own both books (damn bloody expensive but pretty invaluable for learning German armor tactics, production, etc). ASL Vet, if you could please point out the page numbers. It's been a very long time since I've read these books. If anyone can afford the steep price, definitely get these books. They are extremely intereting.[/QB]<HR></BLOCKQUOTE>

They can basically all be found between pages 204 and 224 in Volume 2 - I was just taking choice bits from between these pages.

[Battlefront.com]

Skipper:

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

Yup, that is what I said

<BLOCKQUOTE>quote:</font><HR>Either way, 152mm SPGs (as opposed to tanks) could fire twice as rapidly. <HR></BLOCKQUOTE>

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

[Michael Emrys]

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

I think that CM2 fever is starting.<HR></BLOCKQUOTE>

I noticed the same thing a few days ago.

:eek: :cool:

Michael

[Michael Emrys]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Vanir Ausf B:

The funny thing is that it was actually a misunderstanding of what Steve said that started this. I went back and looked and Steve did say 1.5 shots per minute, not one shot per 1.5 minuets as the original poster thought.<HR></BLOCKQUOTE>

I told you so. But would anybody pay any attention? Nooooooooooooo!

Michael

[Michael Emrys]

Earlier in this thread, there was some comparison of initial vs. sustained ROF. I wish someone with real knowledge would clarify a point for me. I had previously read that one reason, if not the chief reason, why the sustained ROF is slower for most guns is because the gun is heating up and after a minute or two the heat is accumulating faster than it can be discarded without slowing down the ROF.

Michael

[ 06-06-2001: Message edited by: Michael emrys ]

[Battlefront.com]

Michael,

That is correct. In theory, the crew risks "cooking off" a round at the breech end. Not a nice thought This is as true for a large gun as it is for a small arms weapon. For example, I saw a M-60 gunner try to fire something like 500 rounds through his weapon on a 100 deg day in the sun. He got about 50 rounds in and a misfire/jam. Then a few more shots, then another misfire/jam. And that was all she wrote for a while because he couldn't even extract the case from the barrel until it cooled down.

For a large weapon like a large field howitzer, crew fatigue also comes into play. After a while men do get tired of tossing 40lb rounds around at top speed The rate of slowing down does, of course, dependd on the crew and the conditions.

CM does not simulate either of these things because it is, for the most part, not relevant to a small scale combat engagement like this.

Steve