Steve (BTS): ROF of ISU-152

[Commissar]

<BLOCKQUOTE>quote:</font><HR>Originally posted by ASL Veteran:

[QB]I managed to dig up some stuff in “Panzertruppen Vol 2” about Tiger II vs Joseph Stalin tanks from a report written by Hauptmann Fromme, commander of schwere Panzer-Abteilung 503.

QB]<HR></BLOCKQUOTE>

Isn't the Tiger II supposedly mechanically VERY unrealiable? My understanding is that it often broke down. It was a real bastard when well placed in a defensive role but too bloody slow as an effective platform for mobile warfare and had serious reliability problems. As CM models it, it seems too easy to take out with 76mm tungsten rounds. At least to me it's not worth getting.

I don't blame the Russians for avoiding Tigers. Apparently the IS-2 was meant as a heavy breakthrough tank and its main targets were infantry and AT guns. At the same time, what was the realitic liklihood of meeting a Tiger or Tiger II? I doubt it was very great since not that many of them were built.

Concerning the reliability of German/Russian reports, the only proof other writers on this board have given, as far as I can see, is that since these reports are Russian they can't be trusted because they don't correspond with German sources. Well, that logic would work if German sources are necessarily more objective and avoid bias/propaganda. The possibility that Russian or German reports may be nationalistic propaganda is not proof that they necessarily are. Proof that a Russian report is false does not exist merely because a German report states something different. Why should German reports be more reliable and any less nationalistic than a Russian one? I am not sure about the nature of Valera's sources but doesn't he use a lot of Glantz's work as well? Or is Valera merely being selective an ignoring a lot of contradicting reports? If anyone can really say, speak up dammit and join the fun!

Again, if someone can explain and show me why a German observation/report should necessarily hold more credibility I really would like to know. My knowledge of the Eastern Front has been mainly shaped by German assertions and other Western arguments. After reading Erickson and Glantz's works ("The Road to Stalingrad/Berlin", "When Titans Clashed"), I've begun to doubt the veracity of those early claims. Glantz likes to point out that much of what we know about the Russian role in WW2 has been corrupted by sheer ignorance, anti-Soviet propaganda during the Cold War, and German generals/officers seeking to excuse their failures on Russian numbers rather than any sense of Russian operational/tactical skill especially in the later years of the war. Is Glantz overstating this? Although Glantz uses a lot of Russian sources, doesn't he also compare them to German sources as well?

Again, I'm not saying anyone is right or wrong. I just want to know. Thanks

[ 06-05-2001: Message edited by: Commissar ]

[JasonC]

Now, just to get things clear, what did I say about ROF? I said the howitzer size guns will do 3-4, the medium guns you load single piece with two hands can do about twice that, or 6-8, and the light ones you can load with one hand will do less than twice -that-, more like 1.5 times that, or 9-12.

So ASL vet for some reason gets his shorts in a knot about such a claim, and instead cites a source he likes, who says - what exactly?

"Wolfgang Fleisher and he has the following ROF:

152mm Tank Howitzer 1938/40: 2 RPM

122mm 1943 Tank Gun (D-25 T): 2-3 RPM"

Seperate loading howitzer sized ammo. Incidentally, the 1938/1940 model means the field gun. No tank mounted that caliber until several years later. The 152mm was the standard heavy Russian field piece, and the 122mm was the standard Russian medium - like 105s and 155s (or 150s) in other armies.

What about medium stuff that you load with two hands, but in one piece?

"76mm 1940 and 1942 Tank Gun (F-34): 5 RPM

76mm 1938/39 Tank Gun (L-10): 4-5 RPM

85mm 1944 Tank Gun (ZIS-S-53): 4-7 RPM"

Says ASL Vets prefered source. I said 6-8. The first two of those above, if fired from T-34s anyway, mean 2 man turrets, too, which might mean -1 round for the two-timing commander.

What about guns light enough to load with one hand? The only such on ASL Vets list was -

"45mm 1938 Tank Gun: 12 RPM"

Gee, what did I say? 9-12.

So, where exactly is this source violently disagreeing with any of my statements?

Oh, and he also cited the Tiger in CM firing 6 times a minute. Which, last I checked, is included in "6 to 8". And is included in "medium shell that loads in one piece, but with two hands".

So what is the sum total of the differences? About -1 rpm for two or three of the guns. In 2 man turrets, or for a field piece (where you don't exactly stack the shells 3 feet from the gun if you can help it).

His source sees the same relation between ROFs, but is a little more generous to the lightest guns - twice the howitzer rate for the tank gun size, and twice that again for the light tank gun size. 3 6 12 or 4 8 12, that is the sum of the range of opinion. And I said what? 3-4, 6-8, 9-12.

If one bothers to go to great lengths to violently disagree with somebody, it helps first if you pause and see if actually you do disagree with him at all.

There is no reason to expect large ROF differences between seperate loading howitzer style guns. Nor between tank sized medium guns (two hand one piece loaders). Nor between light one hand, one piece loading guns. The human beings are basically the same, the motions are the same, the weights all require the same hands on and the same muscle movements. Why on earth would people expect big differences, besides those couple items?

[Stalin's Organ]

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

The su-85, su-100, su-122, and these bigger types all lacked MGs and would not be in the breakthrough force but rather the overwatch second echelon.<HR></BLOCKQUOTE>

Sure they'll stay back a bit - there's no need for them to "mix it up", but, er......so what?

"The breakthrough force" isn't just the first line of infantry. It's everything assigned to achieve the breaktrhough - that includes the SP guns assigned to support teh offensive.

What's the use of big SP guns if they're not going to support the attack? Exploitation? Looking at eh speed and rangge and ammo figures for ISU-152 it doesn't look much like a whippet to me!! More an elephant - knock 'em hard, make the gap, let the hounds loose!

[Paul Lakowski]

Hey Jason if you continue to write in clear short snappy paragraphs ...I may just have to read more of your posts

Keep up the good work and thanks for the insight into your loading howitzers experiences. Are they as loud as they appear?

[ASL Veteran]

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

Incidentally, the 1938/1940 model means the field gun. No tank mounted that caliber until several years later. The 152mm was the standard heavy Russian field piece, and the 122mm was the standard Russian medium - like 105s and 155s (or 150s) in other armies.<HR></BLOCKQUOTE>

Sorry Jason, but the KV2 mounted the 1938/1940 model, so yes it was mounted in a tank. The 152mm carried by the SU-152 and ISU-152 was the 1937/43 ML-20S so the KV2 was the only tank to carry the 38/39 model as those later vehicles carried a different weapon.

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

If one bothers to go to great lengths to violently disagree with somebody, it helps first if you pause and see if actually you do disagree with him at all.<HR></BLOCKQUOTE>

A discussion about a topic does not necessarily mean a violent disagreement. It is simply a discussion about the facts - and sometimes after discussing things with the fine people on this forum we find that what appeared to be an ironclad truth is not so ironclad anymore. I'm still of the opinion that 4 is too high, and one could easily switch the 2 - 3 to 2 after further review. A difference between 2 and 4 would be fairly significant I should think - especially if your Soviet tank is sitting in front of a King Tiger or something.

[Greg Deych]

Besides the armor penetration of the 152mm round, you have to consider the blast effects. Even in the beginning of the war, German artillery was able to score kills on T34s and KV-1s by literally dislodging the turret from the hull. A 152mm or 122mm HE round would definitely be capable of doing that to a Tiger or a Panther, even if it didn't penetrate the armor as such.

Oh and about the Ferdinands...unless it's a official battle assessment (and maybe not even then), it's very likely to be another, more common type of Assault Gun. After the Kursk, Ferdinand quickly became the "Tiger" of German AGs, basically any turretless vehicle could be reported as a Ferdinand.

[Grunto IV]

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

regardless of how good you think the rules are, they are still utterly irrelevant unless you can show the figures that went into them, and if yuo can do that then why bother mentioning the rules in the first place?<HR></BLOCKQUOTE>

everyone knows; asl was the ultimate in realism.

andy

[Stalin's Organ]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Grunto IV:

everyone knows; asl was the ultimate in realism.

andy<HR></BLOCKQUOTE>

Cough....

a sad commentary on the intellect of the average gamer!!

:eek:

[ 06-05-2001: Message edited by: Stalin's Organ ]

[Freak]

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

Roksovkiy:

If your nick is after Marshall of Soviet Union K.K.Rokossovskiy, check your spelling. Then we'll talk.<HR></BLOCKQUOTE>

Yes, but it is commonly spelled Roksovkiy in many WWII articles and accounts. Don't think the mispelling of Roksovkiy devalues one's opinion.

[Amedeo]

Again, it may be true that both Achtung Panzer! and the RMZ contain biased reports but nonetheless they are among the best sites on German and Soviet WW2 armour, containing material not found elsewhere.

As I said, what is absolutely important in evaluating the performances of the D-25 gun armed AFVs against the Panther (and other German heavies) is that two main factors enter into play that is the type of 122mm round used and the level of flawness into the Panther glacis.

What most wargames failed to address (including ASL and SPWaW, that are wonderful games anyway IMHO) is that the performance of a given AP round against sloped plate cannot be determined simply taking its performance against vertical plate and compare it to the straight LOS path through the sloped armour. And this is especially true for blunt tip rounds as the BR-471B!

So the accounts about IS-2 tanks failing against Panthers at 700m, IS-2 tanks destroying Panthers at 1500m and tests at Kubinka with Panthers destroyed at 2500+m are not in contradiction with each other because they are relative to different conditions, pro-Soviet or anti-German bias has nothing to do with this.

Lastly, one of the biggest merits of CMBO and its game engine lies in having addressed points as variable slope modifier and shatter gaps that are vital to accurately model tactical combat but were overlooked by virtually all the older wargames.

Regards,

Amedeo

[Skipper]

Tactical employment of various SUs in offensive operations, as I understand it, was as follows:

During the initial assault to break through the first line of prepared defences, all of these machines would take direct fire positions in support of the assault.

Then, they would follow about 400 m behind forward elements of the assault.

After breakthrough is achieved, in exploitation phase, light assault guns would be semi-permanently attached to mobile groups as their own artillery, firing either direct or indirect, depending upon the situation. Key thing here is that they had approximately the same mobility characteristics as medium tanks.

Tank killers (SU-85, SU-100) would be used to secure flanks against armored counterattacks. Heavies would be used as a supporting artillery in control of higher commanders.

Of course, none of these statements here is cast in iron - fluid situation means a lot of improvisation.

By the way, the best thing about SU-76 is not it's tank killing ability, but the fact tha it could go virtually anywhere a horse could, and much faster than a horse.

[Skipper]

Some comments.

D25T is a tank gun, not a field gun. That's what 'T' in the index stands for.

>Okay, I am now in front of my

> source "Russian Tanks and Armored Vehicles

> 1917 - 1945" by Wolfgang Fleisher

>...

> 122mm 1943 Tank Gun (D-25 T): 2-3 RPM

Obviously, IS-2's rate of fire should be different from ISU-122, as the latter had same gun but 2 (two) loaders. I repeat this here because this point is perhaps still not grasped by some. So, which vehicle is your book talking about?

> Oh and about the Ferdinands...unless it's

> a official battle assessment (and maybe

> not even then), it's very likely to be

> another, more common type of Assault Gun.

Precisely. Those were 'ferdinands', not "Ferdinands', if you see what I mean.

> I don't blame the Russians for avoiding

> Tigers.

Russians won - thus making 'blaming' themselves for anything like that largely irrelevant.

> Don't think the mispelling of Roksovkiy

> devalues one's opinion.

When it's a nick, it does! As well as when it is in a printed article. The marshall's name was ROKOSSOVSKIY.

[Jeff Duquette]

Someone had suggested that a good comparison of ROF of the SU-152 would be that of the towed version of the 152mm. From German testing of the M20; Feuergeschwindigkeit is the entry of interest. ROF = 3 to 4 rpm.

German testing of the 1938 version of the towed 152mm was also 3 to 4 rpm.

[Roksovkiy]

> Don't think the mispelling of Roksovkiy

> devalues one's opinion.

When it's a nick, it does! As well as when it is in a printed article. The marshall's name was ROKOSSOVSKIY.

I used Roksovkiy, the name of a tanker ,not related to the marshall's name that was ROKOSSOVSKIY.

[Skipper]

> I used Roksovkiy, the name of a tanker

Err... sorry then. But the name doesn't look right in any language, anyway. Can you tell somewhat more about that tanker?

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>Skipper Said: By the way, the best thing about SU-76 is not it's tank killing ability, but the fact tha it could go virtually anywhere a horse could, and much faster than a horse. <HR></BLOCKQUOTE>

I think Soviet crews used to call the SU-76 “The Bitch”. It wasn’t supposed to be a nick-name bread from love of the machine.

[ASL Veteran]

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

Obviously, IS-2's rate of fire should be different from ISU-122, as the latter had same gun but 2 (two) loaders. I repeat this here because this point is perhaps still not grasped by some. So, which vehicle is your book talking about?<HR></BLOCKQUOTE>

At the bottom of my original post, you will note that the ROF figures are without regard to the firing platform. Therefore, the book is not referring to any specific vehicle, just the gun itself.

[ASL Veteran]

Excellent post Jeff. I would think that the ROF for the field piece would be the max practical ROF, and that we can probably make an assumption that the ROF of any AFV mounting that weapon would be something less than that (considering the fighting compartment would be more cramped in an AFV than troops manning a field piece sunbathing out in the open fields)

[Dittohead]

With such a slow ROF it will be even more important to have the right shell loaded in the breech. I can see people cussing when the german tank shows up and their su-whatever takes 8-10 seconds to AIM and fires HE then another 30 sec to load AP. By then the German tank has fired 4-6 times. :eek:

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>ASL Said: and that we can probably make an assumption that the ROF of any AFV mounting that weapon would be something less than that (considering the fighting compartment would be more cramped in an AFV than troops manning a field piece sunbathing out in the open fields)<HR></BLOCKQUOTE>

Agreed. In addition the crew for the towed M20 is probably 12 to 15 guys.

[Skipper]

> Therefore, the book is not referring to

> any specific vehicle, just the gun itself.

With one or two loaders, regardless? Are you kidding me?

[JasonC]

Good point about the KV-2, which I overlooked. I bet that was slower than other mounts, in action, for other reasons. E.g. the turret was super slow, and so heavy that it couldn't be tranversed if on a modest slope.

I agree also with the point about hashing things out. The difference between 2 and 4 might well be important, so why not split the difference and make it 3 rpm? LOL. I think that is a likely "regular" figure anyway. Greens might be somewhat slower.

[JasonC]

An excellent bit of digging, Jeff. It confirms what I have been thinking. We can get 3-4 rpm through such pieces today, and not much has changed. The Germans say they got 3-4 through the capture Russian field piece versions, which makes perfect sense.

The ROF might be somewhat lower for green troops - meaning 3. And for particularly cramped fighting spaces, especially with one loader doing everything, it might be somewhat lower even for regulars in the case of particular vehicles. But the basic point I don't think can be seriously doubted, that the size of the gun and the manner in which it is normally worked allows 3-4 rpm.

[ASL Veteran]

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

> Therefore, the book is not referring to

> any specific vehicle, just the gun itself.

With one or two loaders, regardless? Are you kidding me?<HR></BLOCKQUOTE>

I'm really not sure what you are driving at here. Jeff posted something that gave the field piece a ROF of 3-4 so a ROF range of between 2 and 3 for an AFV seems perfectly reasonable to me. Especially since that is the ROF that you posted when starting the thread. Are you now of the opinion that the ROF of an AFV should be identical or greater than the ROF of the field piece just because there are two loaders?

I think a reasonably objective way of looking at it would be maybe a top end of 3 for the SP guns with two loaders, lower for lower quality crews and a top end ROF of 2 for an AFV with only one loader, lower for lower quality crews. So maybe a regular crew on an SP gun would be in the area of 2 to 2.5 RPM and with a single loader 1 to 1.5 RPM. Seems reasonable to me anyway.

[ 06-05-2001: Message edited by: ASL Veteran ]

[JasonC]

On the stories of turrets blown off by field artillery by HE blast alone, I wouldn't believe too many of them.

155mm arty can get mobility kills by disabling a track or suspension, which are much easier because that system is already under severe mechanical strain to hold up the tank, and outside the main armor. Rear deck direct hits can also wreck the engine and score mobility kills. Barrels can be bent or perforated to produce firepower kills.

And sometimes, though rarely, AFVs are taken out completely by field artillery direct hits when unbuttoned. Heavy barrages will also frag off the antennas and damage the sights of some vehicles, regularly. Concussion effects on the crew were not exactly pleasant, either. But plain HE up to 155mm rarely KOs full tanks (as opposed to light armor).

The stories of Russian tank turrets blown off by artillery are almost certainly effects of artillery-sized HEAT rounds. When the Germans went into Russia, they did not have many weapons capable of KO'ing a T-34 or KV from the front at range. The 88 FLAK could do it with AP, and the field guns of the artillery could do it with HEAT.

The penetration of 105mm HEAT was about the same as the 88mm FLAK at 1500 meters. The penetration of 150mm HEAT was twice as high. Normally, field guns avoid direct-fire engagements with tanks, but in the circumstances the Germans made regular use of batteries of field pieces for anti-tank work. Motorized artillery kept right up with the Panzer columns.

One difficulty with this idea, though, is the slower velocity of howitzer shells (about half the speed of an 88's), makes hits somewhat harder to obtain, especially at long range or with a moving target.

The problem of destroying tanks with artillery HE was well understood, and one of the reasons for the later development of ICM artillery rounds (improved conventional munitions, aka "bomblets"). Now, they didn't invent those because they noticed 155 fire missions wiped out whole tank companies with plain HE. They don't.

Another example of artillery HE engaging medium tanks occurred early in the Korea fighting, the famous case of Task Force Smith. They had 6 105mm howitzers with them that day. But only 5 HEAT rounds in the whole battery. They gave all the HEAT to one gun to function as an anti-tank gun on the main road, and left the other 5 to fire HE in support as a battery. Then they were attacked by around 30 T-34/85s.

The 105mm with HEAT destroyed 2 T-34s with frontal shots, although one of the two also took numerous 60mm bazooka hits in the side and rear, so the exact killer is not known. Then the HEAT was gone, and the lone 105 up front quickly KOed afterward. The T-34s rolled through the infantry position (shrugging off side turret hits from 75mm recoilless rifles and dozens of bazooka hits), past its vehicles shooting them up, and then past the battery position, still in column along the road.

They were buttoned and did not locate the battery easily. Each tank fired only 1-2 shots as they drove past and pushed on. One gun was taken out by this fire, the other four were untouched. In return, they KOed five more T-34s with plain HE. But they didn't get a single penetration, and they didn't blow any turrets off.

What they did instead in the case of the five they got, was put dozens of rounds into their tracks and suspensions. With 4-5 guns firing, the tanks faced 25-30 shots apiece running past one by one on the narrow road. Those that took serious track damage were stopped in view of the guns and hit again and again. The crews abandoned them.

If that battery had abundant HEAT, those tanks would not have made it past alive, driven the way they actually were, which was obviously very green. Until infantry came up to spot for them or force the guns to displace, anyway. But against only HE, made it past they did despite numerous direct hits, with a mobility kill the only feasible thing a 105 could do to them.