US tank design and philosophy

[futon]

10 hours ago, old_goat said:

Exactly. Already in the second half of 1943, it was an undeniable fact for the soviets that the T-34/76 was utterly inferior to Tigers and Panthers. Even worse, it was also inferior to Pz.IVG/H and Stug IIIG. Losses were simply unsustainable. Yes, it is true that frequently the main problem was poor leadership, but it doesnt change the fact that the T-34/76 was simply uncompetitive vs german tanks and assault guns. For all its good points, the same is true for the 75mm Sherman.

75mm APCR or even HEAT was a no go for the Sherman. Maybe it could have partially solve the problem vs Pz IV and assault guns, but thats all. APCR and HEAT had less after armor effect than normal AP. Neither was popular in german tanks. The americans did the right thing to install the 76mm. It was very effective vs Pz.IV/StuG, and below 800-1000m, still useful vs Tigers and Panthers. 

 

Considering that both the Soviets and the US leapfrogged in 1941 to move to put duel purpose 75/76 in a turret on a medium tank, it couldn't have been too hard to have the forsight that upgrading beyond the 75mm may likely be necessary. The Soviets did it. The Americans were slower. 

Of course the timing of the 76mm on the M4 wasn't bad, but it was because it benefitted from production numbers, air superioity, etc, so I'm not really persuaded by secondary design criteria (ammo storage, etc) taking priority over primary design criteria (firepower, etc). Surely the US industry could leapfrog again sooner if it really wanted to.

Edited January 15 by futon

[Interlinked]

The whole topic was a victim of circumstance rather than legitimate design restrictions, IMHO. It's not that fitting a more powerful gun in the original Sherman turret was hard, but U.S. ordnance design conventions made powerful guns bigger than they should have been. U.S. tank guns followed a common artillery recoil system layout with the barrel between two recoil cylinders, the same as the M1916 field gun, just flipped sideways. That made the gun much wider across its recoil guards than it actually had to be, especially if you compared it to the 76.2mm and 85mm in the T-34, and the D-25 in the IS-2, where the recoil system was packaged in a sort of naval-style layout to not exceed the width of the breech. The 85mm in particular actually fits within the same dimensional constraints as the 76.2mm despite the huge increase in firepower.

The compact M6 gun in the M24 showed that if they wanted it, the army could have 75mm firepower in a much smaller package with a concentric recoil system. But the next tank gun to have that feature was the M68 many years later.

Also, the 76mm could have had a HE shell as potent as the 75mm one. If good fragmentation effect was incompatible with a high muzzle velocity with the steel of the time, the charge could just be reduced. The 75mm vs 76mm false dichotomy should have never existed if it weren't for circumstantial roadblocks.

[seahawk]

Imho we need to differentiate between the Western and Eastern Fronts. Engagement ranges in the West were much shorter and we have anecdotes of 75mm taking out Tiger, Panthers and Pz IV with relative ease in sone situations.

On the eastern front, due to the open terrain, engagement ranges were longer.

[DogDodger]

On 1/13/2025 at 11:25 PM, futon said:

The T-34 got the 85mm about, maybe 9 months earlier than M4 got the long 76. Although, the Soviets probably were more impacted by tank warfare thus probably felt the necessity to upgun more strongly.

Production of 76 mm gun Shermans began in January 1944. When are we asserting T-34-85 production began?

1 hour ago, Interlinked said:

The compact M6 gun in the M24 showed that if they wanted it, the army could have 75mm firepower in a much smaller package with a concentric recoil system. But the next tank gun to have that feature was the M68 many years later.

The combination gun mount M78 in the M47 tank used a concentric hydrospring system.

[Interlinked]

9 minutes ago, DogDodger said:

The combination gun mount M78 in the M47 tank used a concentric hydrospring system.

I stand corrected. Poor M47 doesn't get the recognition it deserves once again.

[futon]

2 hours ago, DogDodger said:

Production of 76 mm gun Shermans began in January 1944. When are we asserting T-34-85 production began?

Wiki has T-34-85 1943 model starting production in Janu... ohhhh I checked again, it looks like its January 1944 to March 1944. I took it as January 1943 to March 1944. Oopsie. 

Edited January 15 by futon

[Markus Becker]

17 hours ago, old_goat said:

Exactly. Already in the second half of 1943, it was an undeniable fact for the soviets that the T-34/76 was utterly inferior to Tigers and Panthers. Even worse, it was also inferior to Pz.IVG/H and Stug IIIG. Losses were simply unsustainable. Yes, it is true that frequently the main problem was poor leadership, but it doesnt change the fact that the T-34/76 was simply uncompetitive vs german tanks and assault guns. For all its good points, the same is true for the 75mm Sherman.

BTW, when talking about 76mm T-34 and 75mm M4 we must not forget that the T34/76 had a two man turret, no commander's cupola and for some time not even a radio. 

It would not surprise me if the driving force for the bigger turret was that and not so much a bigger gun. 

[bojan]

Problem with 2-men turret was realized pre-war, hence pre-war T-34M redesign. But war realities were such that shifting production to a totally different tank and still untested tank with same gun was too risky, so T-34 received only "under the surface" upgrades until it has became clear that 76mm was inadequate.

[old_goat]

2 hours ago, Markus Becker said:

BTW, when talking about 76mm T-34 and 75mm M4 we must not forget that the T34/76 had a two man turret, no commander's cupola and for some time not even a radio. 

Yes, and despite the similarities of the two tanks on paper, the Sherman was a far better design. I'd even dare to say that the early M4, together with the Pz.IVF2/early G were the best tanks in the world, in 1942. (not counting the Tiger of course)

2 hours ago, Markus Becker said:

It would not surprise me if the driving force for the bigger turret was that and not so much a bigger gun. 

Definitely the bigger gun. 76mm was totally impotent vs the big cats, especially against the Tiger. Also it had problems with the Stugs, and the front hull of the Pz.IVG/H.

[Manic Moran]

7 hours ago, seahawk said:

Imho we need to differentiate between the Western and Eastern Fronts. Engagement ranges in the West were much shorter and we have anecdotes of 75mm taking out Tiger, Panthers and Pz IV with relative ease in sone situations.

On the eastern front, due to the open terrain, engagement ranges were longer.

I have not seen an assessment of engagement ranges for the US 75mm in North Africa, but I suspect they are somewhat longer as well. For the record, the longest ranged tank kill I'm tracking in the war is claimed by C/805 TDB in Italy, two tanks at 12,500m.

[Rick]

1 hour ago, Manic Moran said:

I have not seen an assessment of engagement ranges for the US 75mm in North Africa, but I suspect they are somewhat longer as well. For the record, the longest ranged tank kill I'm tracking in the war is claimed by C/805 TDB in Italy, two tanks at 12,500m.

With what?

[Markus Becker]

3" with indirect fire, I guess. M10s were used as SPAG. 

[EchoFiveMike]

Or it's a typo, and they meant a far more believable 1250 yds.  S/F....Ken M

[Manic Moran]

1 minute ago, EchoFiveMike said:

Or it's a typo, and they meant a far more believable 1250 yds.  S/F....Ken M

It was semi-indirect using HE from the 3" guns.

[seahawk]

3 hours ago, old_goat said:

Definitely the bigger gun. 76mm was totally impotent vs the big cats, especially against the Tiger. Also it had problems with the Stugs, and the front hull of the Pz.IVG/H.

But that was not the reason for the 85mm. Tiger I was, and that can be simple seen by the fact that the go ahead for T34-85 came before the heavier armoured version of the Pz IV were seeing service.

So we have look at different developments happening at the same time.

Soviets:

T-34-76 was not able to deal with Tiger I, T-43 would have been too much a change in production, so they combined T-43 turret and a modified T-34 hull. T-43 and T-34-85 would not be able to resists a hit from a 88mm, but should be able to penetrate a Tiger.

Germans:

Pz IV F was finally able to penetrate the T-34-76 with ease, but the T-34 was also able to penetrate the PZ IV with ease, so extra armour was added to the Pz IV to give it more protection and reduce the range at which the T-34 can penetrate the Pz IV.

[RichTO90]

12 hours ago, Interlinked said:

Also, the 76mm could have had a HE shell as potent as the 75mm one. If good fragmentation effect was incompatible with a high muzzle velocity with the steel of the time, the charge could just be reduced. The 75mm vs 76mm false dichotomy should have never existed if it weren't for circumstantial roadblocks.

It is curious that the British also had a blind spot regarding the propellant load for the 17-pdr HE and had to redesign it with a lower Mv. The Germans did not.

[RichTO90]

4 hours ago, old_goat said:

Definitely the bigger gun. 76mm was totally impotent vs the big cats, especially against the Tiger. Also it had problems with the Stugs, and the front hull of the Pz.IVG/H.

That would be a surprise to all those "big cats" StuG and Panzer IV knocked out by the 75mm M3 and 76mm M1 guns.

Edited January 15 by RichTO90

[old_goat]

35 minutes ago, RichTO90 said:

That would be a surprise to all those "big cats" StuG and Panzer IV knocked out by the 75mm M3 and 76mm M1 guns.

Of course Tigers and Panthers were knocked out by 75mm M3. But it wasnt always possible to flank them. By 76mm, I meant the soviet 76. Not the american, which was significantly more powerful. 

I see one big problem with assessment of allied vs german stuff. In the west, most authors base their opinions on mainly the western front experience, which was vastly different than eastern front. As I said before, 75mm Shermans didnt shine in the east at all. There is very little literature about the eastern front battles (especially 1944-45) in english that uses most recent research. Only old myths repeated over and over again. 

 

[Tim the Tank Nut]

I thought there was a memoir about a Russian tanker that served on Shermans with great success?

[shep854]

21 minutes ago, Tim the Tank Nut said:

I thought there was a memoir about a Russian tanker that served on Shermans with great success?

I think he got to play with a 76mm Sherman.

[Manic Moran]

Dmitry Loza, "Commanding the Red Army's Sherman Tanks". He did like them, but the problem is it's a data point size of one.

Peter Samsonov did a book about two years ago of the Soviet experiences with the M4, but he pointed out that evaluations and opinions of the tank itself are hard to come by: All you can do is see how the tank performed and draw your own conclusions, with occasional high-level commentary from specific units. (Mainly the complaints were the high vertical sides making tempting targets and with the running gear).

[RichTO90]

German Engagement Ranges Ostfront from Soviet POV

Ballistic Research Laboratories Report No. 590, "The Range and Angular Distribution of A.P. Hits on Tanks" by R. H. Peterson, APG, December 1951. Average range of opening combat for tanks was 660 yards. "It is to be noted that the range at which the most encounters took place was 300 yards or 1/2 the average range." "For example, from the graph 67% of all engagements were at ranges greater than 200 yards and 65% were at ranges greater than 400 yards. Hence 22% or about 1/5 of all engagements were at ranges between 200 and 400 yards. Only 2% of all engagements were at ranges greater than 2000 yards."

E. Benn and R. W. Shephard in December 1951, WO 291/1212, "Ranges of engagement in the ATk battle"

90% of engagements occur at less than 2200 yards
80% of engagements occur at less than 1500 yards
50% of engagements occur at less than 650 yards

AORG Memo No. C6, "A survey of tank warfare in Europe from D-Day to 12 August 1944", by H.G. Gee, May 1952 (WO 291/1218), based on 112 tank vs. tank actions fought by 21 AG gives the mean engagement ranges for this sample as 400 yards in close country, and 1200 yards in open country.

BRL Memo No. 798, "Data on World War II tank enegagements involving the US Third and Fourth Armored Divisions", by D. C. Hardison, June 1954, based on 86 tank vs. tank and tank vs. anti-tank engagements gives the average ranges at which tanks were destroyed, in yards, as:

Allied tanks__Enemy tanks__Place
476____________N/A_______Vicinity Stollberg
959____________733_______Roer to Rhein
1000___________833_______Belgian Bulge
1260___________936_______Vicinity Arracourt
1116___________831_______Sarre
731____________915_______Relief of Bastogne

The overall mean casualty ranges are given as 946 yds for Allied and 893 yds for enemy tanks.

 

[Markus Becker]

14 hours ago, Interlinked said:

Also, the 76mm could have had a HE shell as potent as the 75mm one. If good fragmentation effect was incompatible with a high muzzle velocity with the steel of the time, the charge could just be reduced. The 75mm vs 76mm false dichotomy should have never existed if it weren't for circumstantial roadblocks.

In a way the 76mm HE was as potent as the 75mm's. Yes, the explosive charge was smaller but the superior accuracy of the 76mm allowed you to put it right where it was needed even if that place was a vit out of the accuracy zone of the 75mm. Thus M10s playing assault gun behind M4s. 

[seahawk]

Logically the defender fire from longer ranges than the attacker. In the end anything above 1000m needs favourable conditions in WW2. You need the terrain, you need the weather and you need your vision to not be restricted by smoke or dust kicked into the air by artillery fire.

Now add that according to German doctrine an ideal defensive position would have a terrain obstacle about 300m in front of the first defence line, so that tanks and AT guns positioned behind the defence line can engage enemy targets from an effective range with a good chance of hitting the target, while only the first line of enemy forces can see the firing positions of the Germans. PAKs were not positioned in lines but in concentrated positions capable of firing 360° and covering each other. Those positions were fortified and protected by mine fields. They engaged from about 200-300m in front of the first main defence line well into the engagement area, which often reached deeper into friendly lines, as infantry was expected to attack tanks at close range or let them roll past. The job of the infantry and the artillery was to clear the enemy infantry from the enemy tanks. The tanks would be handled by friendly tanks or PAKs. A penetration of the defence line by enemy tanks was planed. 

[old_goat]

19 minutes ago, Manic Moran said:

Peter Samsonov did a book about two years ago of the Soviet experiences with the M4, but he pointed out that evaluations and opinions of the tank itself are hard to come by: All you can do is see how the tank performed and draw your own conclusions, with occasional high-level commentary from specific units. (Mainly the complaints were the high vertical sides making tempting targets and with the running gear).

Experience with Mk.9 Valentine and M4A2 Sherman during operation Wanda:

"... battlefield experience showed that the 57mm-armed MK-9 tanks should be used to protect the flanks of M4A2 formations, or in clashes vs enemy tanks/SPGs, they should be used as assault guns. The M4A2 tanks had many drawbacks, especially their cross-country mobility. The narrow tracks, and the lack of spikes(?) on them caused that the M4A2 tank had difficulty moving on muddy roads, especially in autumn and spring, and also in icy periods...

... The M4A2 and MK-9 tanks performed poorly in battles vs Tigers and Panthers. Using them vs german heavy tanks was incredibly ill-judged, because their losses were significantly higher than the german's."

+ also some reports about the difficulties of T-34s when engaging Tigers/Panthers, 76mm gun being ineffective past 5-600 meters, also some reports that german tanks could destroy them already from 1500-2500 meters, and they had to be protected by Su-85 and Su-152 assault guns. Also that when visibility permitted, germans opened fire even at 2000 meters.

Source: Számvéber Norbert - Ragadozók: A „Bäke” nehézpáncélos-ezred története, 1944. január-február (book from 2021, using lots of original soviet documents as sources)