The Soviet Tank Thread: Transversely Mounted 1000hp Engines

[LoooSeR]

11 hours ago, heretic88 said:

/.../

SU-76M is bad

SU-76M wasnt bad but wasnt good either.

   It wasn't "good" or "bad", it was necessary, as article shows pretty well.

 

11 hours ago, heretic88 said:

Yes, it is true that the SU-76 was a huge improvement over the towed ZIS-3, the importance of added mobility is especially true. But the problem with this vehicle was that it was designed as a light assault gun, so it suffered greatly thanks to its thin armor. Comparing it to the Marder III, and especially the Jadgdpazer 38t doesnt make sense. These are tank destroyers, not assault guns.

   In case of Marder 3, those vehicles are very close to each other in terms of design. SU-79 is light infantry support SPG, which means it can meet tanks and other AFVs as part of umm.. infantry support role, making it both light support gun carrier and tank destroyer. So comparisons are valid.

 

11 hours ago, heretic88 said:

About ISU-122 existance: myth and reality.

OK, although it is a fact that the ISU-122 was still a stopgap vehicle. The ISU-152 had a long career after WW2, even received two serious modernization packages. The 122 was neglected, didnt receive any modernization, its chassis was rebuilt as ARVs and missile launcher platforms.

   Not so much as "stopgap", but positive sides of this vehicle became much less obvious with end of the war and lack of German cats to destroy. It wasn't just a quickly put together half-assed AFV. I suspect that 122 mm gun serious production bottleneck played its role in decision about future of this SPG.

 

11 hours ago, heretic88 said:

About IS tanks

IS tanks were built for a breakthrough role. No doubt the 122mm gun was very useful against german tanks, and it played a role in its adopting. But its power against fortifications was also a key factor. Also it looks like the author tries to marginalize the low rate of fire. It was a BIG disadvantage! First shot kills were exceedingly rare in WW2. You needed to fire several shells to destroy an enemy tank, there were lots of causes, wrong range estimation, stress, not perfectly zeroed sights, etc. This applies to any tank of WW2, IS-2 is not an exception. MHV made a good video about this:

 https://www.youtube.com/watch?v=zpe7qhWu76c  According to original german documents, rate of fire was 6-10 for KwK43. Even in the worst case, its more than double rate of fire compared to IS-2. Massive advantage. 

Then the author compares the ISU-122 to the Jagdpanther. Again, a mistake. Apples to oranges. The ISU-122 was an assault gun, the Jagdpanther a tank destroyer.

 

   He was talking about a myth that IS-2 was purely breakthrough tank that was incapable of fighting other tanks. 122 long barrel mm gun was chosen over any other big caliber howitzers or other short-barreled options because of it's better AT perfomance. 

   ROF of 88 mm gun inside of the tank IIRC was around 4-5 rounds, which is not that much far from 2.5-3 rounds with D-25T.

   ISU-122 is TD, as a gun for it was chosen for being better AT weapon in the first place, compared to 152 mm ML-20. So comparison with Jagdpanther is valid, it is not apples and oranges.

 

11 hours ago, heretic88 said:

Optics

Yes, it is a trend to bash german tanks for their alleged "visibility problems"... "even on Pz.Kpfw.IV, which initially had a lot of viewing devices, by 1944 there was only a commander’s turret was avaliable for viewing of the flanks. Loader became completely blind, and the gunner looked only forward. " Hmmm... Isnt it the case with almost every cold war, or even modern tank?

   What Cold war tanks have to do with Pz4 and German armor in 1943-44? Does lack of visibility from Pz4 suddenly became less of a problem if we start to dig out WW1 tanks?

 

11 hours ago, heretic88 said:

 

This is nothing more than propaganda. I could also tell stories when soviet tanks, with "superior visibility" fell victim en masse to german tanks. And this is from 1944, so nobody can play the "poorly trained soviets" card. 

   Ow, yes, lack of visibility from Panther and other late Germans tanks is purely a Pasholokism!

 

[Pascal]

11 hours ago, LoooSeR said:

ROF of 88 mm gun inside of the tank IIRC was around 4-5 rounds, which is not that much far from 2.5-3 rounds with D-25T.

   ISU-122 is TD, as a gun for it was chosen for being better AT weapon in the first place, compared to 152 mm ML-20. So comparison with Jagdpanther is valid, it is not apples and oranges.

 

The captured King tiger in that test was shooting at targets around a test field(aimed), are there IS-2,ISU-122,SU-152 in the same kind of environment tested for fire rate(aimed)? The stowed ammunition is important too.

 

20 hours ago, Beer said:

Also the bad situation awareness of the Panther and Königstiger is true and combined with relatively thin side armor, sponsons full of ammo (Panther especially) and very slow turret traverse these tanks were indeed very vulnerable from side attacks. Due to the nature of the late war they however often fought from prepared defence positions where it was not such a big issue. Their offensive record is pretty bad nevertheless (also due to low availability, reliability issues and terrible strategic mobility). 

 

The King tiger tested above, in gear 2 at 2000RPM made a 360 in 20sec(gear 1 in 40sec), gear 2 at 1000RPM in 43sec(gear 1 minute 26 sec), gear 2/1 at 500RPM 1 min 15-20sec.

How other tanks are doing regarding their turret rotation speed?

 

[Beer]

1 hour ago, Pascal said:

 

The captured King tiger in that test was shooting at targets around a test field(aimed), are there IS-2,ISU-122,SU-152 in the same kind of environment tested for fire rate(aimed)? The stowed ammunition is important too.

 

 

The King tiger tested above, in gear 2 at 2000RPM made a 360 in 20sec(gear 1 in 40sec), gear 2 at 1000RPM in 43sec(gear 1 minute 26 sec), gear 2/1 at 500RPM 1 min 15-20sec.

How other tanks are doing regarding their turret rotation speed?

 

 

For sure we have bigger experts than me here so take all I write with a truckload of salt 

 

I read elsewhere that in Panther it was 17-93 seconds depending on the gear and it needed 1000 turns of the manual wheel for 360°rotation (Königstiger 700). In emergency at 3000 rpm it should have been possible to rotate the turret in 10 seconds but 3000 rpm was highly non recommended engine speed for the HL230. Somewhere I remmeber to see also a complaint that the manual traverse was not possible at a list of 5° already. For the Tiger I read 25-60 seconds depending on the gear and 720 rotations of the manual wheel. 

 

However the main issue with the hydraulic traverse was its huge dependancy on the cooperation between the driver and the gunner and a very high demand on the crew training. If the tank was on the move the turret speed was subject to shifting speeds, slow and was never constant. In theory since the gunner had only a straight narrow FoV in combination with this he could hardly keep his eyes the target on the move so when they stopped he had to start searching for it again. 

 

Sherman had electrical turret traverse independent on the engine speed, I believe, capable to rotate the turret at 24 second in any circumstances (plus vertical stabilizer).  

 

I found 22-28 seconds for IS-2 with D-25 with manual traverse possible up to the list of 8,3° and powered traverse up to the list of 15°. For T-34-85 I found 21 seconds, for T-34-76 10 seconds. All with electric traverse motor. 

 

For Pz.IV I found 32 seconds for Ausf. H with electric traverse. Ausführung J had only manual allegedly due to lack of copper. 

[SH_MM]

On 3/30/2020 at 8:52 AM, Wiedzmin said:

maybe somebody have more info on T-72 trials in Austria ? or more photos?

 

Three T-55AM tanks, three T-72 tanks, two BMP-1s and two unspecified amphibious/ferry vehicles (might be the GSP-55) were purchased from Germany in 1994, taken from former East-German Army stocks. Austrian crews were trained on all vehicles for a few weeks to properly evaluate the capabilities of the vehicles, including armor penetration of the various types of ammunition.

 

After the trials some of the vehicles were used to test their resistance to the Austrian arms. At least two of the T-72s are/were located in an Austrian military museum, the fate of the third is unknown. It might have been damaged too much during the ballistic tests (which included towing the tanks over anti-tank mines). The tank from the photographs has been used to test the effect of the Ulan's 30 mm ammunition according to an Austrian website, but I believe this to be a misinterpretation by the author.

 

As a result of the evaluation of T-55AM and T-72, the already planned upgrade of the M60A1 to the M60A3 was canceled and a program to purchase a new main battle tank was initiated. This ended up being the Leopard 2A4.

 

No idea what the source for the information from "Quadro" of the model train forum is. He must be talking about different tests.

 

On 3/30/2020 at 12:38 PM, Beer said:

That would mean the Bill was rather useless... 

 

PAL 2000 (RBS-56 BILL-1) has no tandem warhead, only a single shaped charge, which is tilted slightly downwards. The shaped charge jet might hit roof-mounted ERA in a near optimal angle, thus it might be possible for a T-72B with Kontakt-1 or Kontakt-5 ERA to survive a hit by PAL 2000.

 

[heretic88]

22 hours ago, LoooSeR said:

What Cold war tanks have to do with Pz4 and German armor in 1943-44?

Target acquistion wasnt much different in cold war. No panoramic or thermal sights. (except Leo-1) It is primarily the TC who is responsible for target detection. Of course it is nice if the loader has a periscope to look out, but not that important. If it were, why was this periscope dropped from the whole M48/60 family? Gunner side vision slits were dropped even from later ww2 tanks from all sides.

 

German tanks had only one problem with visibility: lack of unity periscope for gunner. And this isnt even a target detection issue, but a target hand off difficulty. Even the french report on the Panther noted the near perfect visibility from the TC's cupola. Additionally, while this cupola was flawed in terms of escaping the tank, it offered an open protected hatch position which enhanced visibility further.

But lets compare the Panther, with lets say, the T-34/85. 

Driver: 2 periscopes forward for T-34/85. One periscope forward, one about 45 degrees to left for Panther.  - slight Panther advantage

Radio operator/bow gunner: small telescope for MG in T-34/85. small telescope for MG, and one periscope to 45 degrees for Panther - clear Panther advantage

Gunner: Primary sight + MK4 periscope for T-34. Primary sight only for Panther - slight T34 advantage for target detection, big advantage for target hand off process

Loader: MK4 periscope for T-34, fixed periscope for Panther - slight T-34 advantage

Commander: cupola with vision slits + MK4 periscope for T-34, cupola with periscopes and hatch with open protected position - clear Panther advantage.

I fail to see how "far superior" the visibility is from T-34, especially because the vision from an MK4 periscope is quite poor. (I checked it personally) The slits in the T-34 cupola are also greatly inferior to periscopes.

 

As for KwK43 rate of fire, another german report says 8rpm

 

 

[heretic88]

8 hours ago, Beer said:

read elsewhere that in Panther it was 17-93 seconds depending on the gear and it needed 1000 turns of the manual wheel for 360°rotation (Königstiger 700). In emergency at 3000 rpm it should have been possible to rotate the turret in 10 seconds but 3000 rpm was highly non recommended engine speed for the HL230. Somewhere I remmeber to see also a complaint that the manual traverse was not possible at a list of 5° already

15 sec @ 3000rpm, 18 sec @ 2500 for Panther. Traverse became impossible at 20 degrees according to french report. 

[ZloyKrolik]

42 minutes ago, heretic88 said:

. Of course it is nice if the loader has a periscope to look out, but not that important. If it were, why was this periscope dropped from the whole M48/60 family?

 

There is a mount for a periscope in the loader's hatch of the M60A1/A3. https://en.wikipedia.org/wiki/M60_tank#/media/File:M60qatar.jpg

[LoooSeR]

   Stolen from otvaga - BMO-T with paint partially removed (to be re-painted). T-72B3 and B3M/UBKh/mod.2016

http://otvaga2004.mybb.ru/viewtopic.php?id=1927&p=5#p1325436

 

 

Spoiler

 

 

Spoiler

 

[Beer]

3 hours ago, heretic88 said:

15 sec @ 3000rpm, 18 sec @ 2500 for Panther. Traverse became impossible at 20 degrees according to french report. 

 

First is highly non-recommended engine speed, the second is allowed maximum engine speed, i.e. first is very very emergency case which can brake the engine, the second is ideal case. None of that is possible without being stacionary and without perfect cooperation between the crew members, in other words in the real world it was most likely unachievable in most of the situations.  

 

 

[Jim Warford]

I think it's important to remember that the D-25 122mm gun was not only very successful in WWII, but it also served well into the Cold War. In fact, the ISU-122 didn't get much attention in the West until it was fitted with a "tank gun" and became the ISU-122S. The ISU-122S fitted with the D-25 (known as the Object 249, SU-249 and JSU-249 while it served with the GSFG in East Germany after the war), got a lot of attention. It was as close to a truly combined assault gun/tank destroyer that had been developed up to that point. Finally, regarding the D-25, fitted to Egyptian IS-3s, it was knocking out Israeli M48s in 1967...using ammo from 1945/1947.

 

 

 

 

 

     

[heretic88]

After WW2, soviets thought differently. They found the ISU-122 much less useful, and began converting them to ARVs and missile platforms in the 1950s. On the other hand, ISU-152 was modernized twice, and served well into the 1970s. There was no need for ISU-122. The army had plenty of tanks with the D-25 gun.

[LoooSeR]

   Few more pics from otvaga

 

Spoiler

 

 

[Jim Warford]

2 hours ago, heretic88 said:

After WW2, soviets thought differently. They found the ISU-122 much less useful, and began converting them to ARVs and missile platforms in the 1950s. On the other hand, ISU-152 was modernized twice, and served well into the 1970s. There was no need for ISU-122. The army had plenty of tanks with the D-25 gun.

 

It's true that the ISU-122S didn't stay in service as long as the ISU-152...my point is that it not only served in East Germany after the war, but it also was a key development in bringing a dual-purpose assault gun/tank destroyer to the field. 122mm-armed assault gun companies (more tank destroyer companies really), were an important part of the Soviet Army until the late 1960s or early 1970s.      

[Pascal]

On 4/18/2020 at 11:53 AM, heretic88 said:

German tanks had only one problem with visibility: lack of unity periscope for gunner. And this isnt even a target detection issue, but a target hand off difficulty. Even the french report on the Panther noted the near perfect visibility from the TC's cupola.

 

The gunners sights on Panther(2,5x-5x) and King tigers(3x-6x) had optics with variable magnification, using least magnification had a very wide view angle. This can be also put to the comparison. The Panther gunner also had a two-dial turret position indicator, that may also have helped.

 

Another interesting thing is the "blindspot" from up to down and how other AFV had their way with it, like in the first image with a side view of a Panther.

Spoiler

 

The accuracy myth is one interesting too, soviets captured a random King tiger and tested it, the R100 is a lot tighter.

Spoiler

Quote

The next is accuracy. According to this indicator, the A-19 and D-25T were equal to the German 88-mm gun Pak 43 L/71 and its tank version. Therefore, theories of inaccurate "logs launcher" are just the fruits of the sick imagination of their authors.

 

   Distance - 2000m. R50 (half of shots) - 72sm, R100 - 130 sm. "+" is point of aim, central part of the group is 10 sm above and 100sm to the right from point of aim.

   To the question of the accuracy of the D-25T. And such accuracy was achieved during standard warranty tests.

[heretic88]

12 hours ago, Jim Warford said:

122mm-armed assault gun companies (more tank destroyer companies really), were an important part of the Soviet Army until the late 1960s or early 1970s.      

I may be wrong, but as far as I know,  ISU-122 was withdrawn in early 60s. Even the more modern SU-122/54 left service in the second half of 60s. For tank destroyer role, the SU-100 was preferred, and retained much longer (early-mid 70s).

[heretic88]

34 minutes ago, Pascal said:

The gunners sights on Panther(2,5x-5x) and King tigers(3x-6x) had optics with variable magnification, using least magnification had a very wide view angle. This can be also put to the comparison. The Panther gunner also had a two-dial turret position indicator, that may also have helped.

True, the low magnification had a relatively wide field of view, but still, an unity periscope, like in the Sherman was better.

 

34 minutes ago, Pascal said:

The accuracy myth is one interesting too, soviets captured a random King tiger and tested it, the R100 is a lot tighter.

Soviet testing of the KT was a joke. But aside that, the 122mm guns were indeed very accurate, and the quality of soviet sights was quite good, almost reaching the german level. 

[Pascal]

1 hour ago, heretic88 said:

Soviet testing of the KT was a joke. But aside that, the 122mm guns were indeed very accurate, and the quality of soviet sights was quite good, almost reaching the german level. 

In what sense a joke?

 

The point on accuracy was that it was equal in the original qoute, which it isn't.

Quote

The next is accuracy. According to this indicator, the A-19 and D-25T were equal to the German 88-mm gun Pak 43 L/71 and its tank version. Therefore, theories of inaccurate "logs launcher" are just the fruits of the sick imagination of their authors.

 

[That_Baka]

1 hour ago, Pascal said:

In what sense a joke?

 

The point on accuracy was that it was equal in the original qoute, which it isn't.

 

May i see captured  KT KWK43 dispersion table?

[LoooSeR]

   T-72s in 2nd Chechnya war. Plenty of tanks had cage armor on turret sides. At 4:30 you can see one 72 with external fuel tanks on fire.

 

[LoooSeR]

   Ekaterinburg

 

Spoiler

 

 

 

 

 

 

 

 

Spoiler

 

 

 

 

[Jim Warford]

9 hours ago, heretic88 said:

I may be wrong, but as far as I know,  ISU-122 was withdrawn in early 60s. Even the more modern SU-122/54 left service in the second half of 60s. For tank destroyer role, the SU-100 was preferred, and retained much longer (early-mid 70s).

 

You're making my point for me...the ISU-122S served until the 1960s...the SU-122-54 (my favorite), served until at least 1969/1970. The SU-122-54 was the first truly combined Soviet assault gun/tank destroyer that had clear advantages over any other Soviet assault gun or tank destroyer. It was killed by the anti-gun/pro-missile mafia, not because of any performance issues. It was accepted for mass production and for upgrading to the M62T-2 gun from the T-10M. The numerous SU-100s weren't preferred, there was just a lot of them around and they were cheap...so they survived for (maybe) a few years longer. SU-122-54s actually replaced SU-100s in tank destroyer companies in selected regiments.  

 

 

          

[LoooSeR]

   Iranian 72s

[Pascal]

On 4/18/2020 at 3:36 PM, Beer said:

 

First is highly non-recommended engine speed, the second is allowed maximum engine speed, i.e. first is very very emergency case which can brake the engine, the second is ideal case. None of that is possible without being stacionary and without perfect cooperation between the crew members, in other words in the real world it was most likely unachievable in most of the situations.  

 

 

 

So i looked in the report on King tiger, regarding the turret, because it had a similar system and there's nothing reported about the system being crew intensive, it's even recommended to use the hydraulic turret system on the move because of it's overall comfort without even including the controlling handles.

 

The whole system is a bit bigger then equivalent hydraulic system specially designed for tanks, the one in King tiger is from machining equipment and that means complex, as a downside is mentioned the engine being off means no hydraulic turret control, other observation being the gunner and loader having both manual turret controls, probably meaning only in rotation not elevation.

 

9 hours ago, That_Baka said:

May i see captured  KT KWK43 dispersion table?

https://litl-bro.livejournal.com/1700.html

There are more docs in that list, the King tiger is under the "Tiger B" name, the .pdf links do not work, download in the original format .djvu and just convert them into pdf with an online djvu to pdf converter, works like a charm.

[Beer]

1 hour ago, Pascal said:

So i looked in the report on King tiger, regarding the turret, because it had a similar system and there's nothing reported about the system being crew intensive, it's even recommended to use the hydraulic turret system on the move because of it's overall comfort without even including the controlling handles.

 

That makes no sense to me. All reports I have seen gave variable rotation times depending on the engine speed for Tiger, Königstiger and Panther. The engine speed was controlled by the driver and nothing else. 

 

As far as I understand the hydraulic system was used only to avoid using scarce copper needed for the electric system. 

[Pascal]

6 hours ago, Beer said:

 

That makes no sense to me. All reports I have seen gave variable rotation times depending on the engine speed for Tiger, Königstiger and Panther. The engine speed was controlled by the driver and nothing else. 

 

As far as I understand the hydraulic system was used only to avoid using scarce copper needed for the electric system. 

 

Yes it's variable and the gunner uses whatever RPM he has while the tank is on the move, i guess the gunner only controls the RPM trough the driver only while the tank is stationary.