T34 Vulnerability

[rexford]

Just how vulnerable was T34 front hull (45mm at 60° from vertical), to 75mm gun on PzKpfw IV and Stug's?

We put together an equation based on German and American tests against high hardness armor, and are looking for actual penetration range statistics to confirm theory. Does anyone know of a source where this data can be found?

The Russian Battlefield lists 1000m, and Jentz indicates 75mm L48 could handle T34 at all useful ranges, or something like that.

Could 75mm consistently penetrate T34 front hull at 1250 to 1500m?

Granted that the situation would not occur very often, but the most distant ranges helps to pinpoint overall vulnerability at closer ranges with lateral side angles cranked in.

Thanks for help.

[rexford]

Anything from Korea when 76mm Shermans or British armor met T34/85's?

[Guest machineman]

This may be of some interest, an American evaluation of a late '42 T-34 and KV-1:

"Armor

A chemical analysis of the armor showed that on both tanks the armor plating has a shallow surface tempering, whereas the main mass of the armored plating is made of soft steel. In this regard the Americans consider that by changing the technology used to temper the armored plating, it would be possible to significantly reduce its thickness while preserving its protective ability (the situation with American armor was even worse. Engineers in Aberdeen have criticized their

armor on Shermans. Soviet engineers have agreed with them because during the comparative trials Soviet ZIS-3 gun could penetrate Sherman's galcis from 1100 metres - Valera). As a result the weight of the tank could be decreased by 8-10%, with all the resulting benefits (an increase in speed, reduction in ground pressure, etc.)"

From:

http://history.vif2.ru/library/archives/stat/stat7.html

Very interesting look at all aspects of the tank. They rate some aspect of the design as excellent and some very poor, coupled with generally poor execution, ie:

"The machining of equipment components and parts was, with few exceptions, very poor. In particular, the Americans were troubled by

the disgraceful design and extremely poor work on the transmission links on the T-34. After much torment they made a new ones and replaced ours. All the tanks mechanisms demand very frequent fine-tuning.."

And:

"The T-34 medium tank after driving 343 km, became completely disabled and that could not be fixed. The reason: owing to the extremely poor air filter...(engine was ruined)"

[Jarmo]

No actual test data, but Pekka Kantakoski's "Punaiset Panssarit" has following mentions of T-34:

75mm gun of PzIV could penetrate T-34 front hull from 600 meters and the tower from 1000 meters.

Tiger's 88 could penetrate T-34 front hull from 1000 meters.

The book lists about 500 other books as sources, so I have no idea where those figures are from, ar if they are reliable.

It's also mentioned that T-34's 76mm could penetrate PzIV's 80mm front hull from 600 meters, and the tower from "a further distance".

[rexford]

Thanks for responses.

Responses from other sites have 1200m range for 75L43 APCBC against T34, penetrating hit at any angle, based on panzer unit report.

Published figures may be either test results, battlefield reports or calculations by bureaucrats far from front, using whatever numbers they can find. Tiger and Panther Fibels use office estimates based on calculations where T34 armor is rolled homogeneous medium hardnessm which misses high hardness aspect.

I'll summarize the other site replies with this thread.

Russian Battlefield has 1000m, which is consistent with panzer report.

[jasoncawley@ameritech.net]

I don't have detailed info on your question. But my sense of things is that the L70, 88s, and high caliber HEAT (from tube artillery, not tank guns) could deal with them from any angle and out to long ranges, 2km or so. But the shorter 75s, I think it was more like 1km.

I know of examples where the German practice was to hold fire in ambush until 600-700 yards, for instance (Pz IVs and StuGs vs. T-34s, 1943 in Ukraine). That is not definitive, since first shot accuracy might have also been a consideration there, but if they had a long range edge, I suspect they would have opened much sooner, for the sake of improved safety on the replies. The Panthers and mobile 88s did so, dueling at quite long range.

Incidentally, the number I have seen for the glacis is 47mm at 60 degrees, for the 1942 models and afterward, which was most of the tanks. It was 45mm in 1940-41, but that was a small portion of the whole fleet made.

Nothing like the detail you are after, but I hope it is of some help.

[:USERNAME:]

The T34 front hull also had the huge driver hatch throughout its design. It wa, of course, needed to get out by the driver since there was no overhead hatch. This same visor type hatch was eliminated from later panthers because it compromises the armor plate. This is a weak spot and should be modeled in CM2.

I wonder if the T34 lower side hull armor is going to be a weak spot in CM2. It was not sloped as well as the upper side hull armor or the turret sides. Weapons like the 37mm PAK and short 50mml42 and 75mmL24 should be able to penetrate it.

[Tanaka]

Just to add up something... Don't forget that when the Americans encountered the T34-85 in Korea they found out that the zook couldn't penetrate the T34 frontal armor, so they come up with the Super Bazooka.

[jasoncawley@ameritech.net]

Here is another combat report. A StuG company (9 vehicles) engaged several T-34s and bagged quite a number of them over the course of 3 hours (17 KOed, 2 immobilized). The unit report adds that the tanks were destroyed at a distance of 600 to 800 meters. And it sees fit to note that a single T-34 was KO'ed at 1000 meters "by 3 shots".

Sounds to me like the kill was marginal from the front at 1 km, and SOP was to tackle them from closer than that. Which fits the limited technical data I've seen, and other reports of 75L43-L48 vehicles holding their fire down to 600-700 meters.

[Jeff Duquette]

The 3.5" M20 Super Bazooka was actually developed during the tail end of WWII. I have yet to run across references to its use in WWII...perhaps on Okinawa?

Part of the bad rep of the 2.36" M9 in Korea comes from poor storage of rockets in Japan. Much of the ammunition that TASK FORCE SMITH and the 21st Infantry REGT'S employed during their first battles in Korea had been in damp storage facilities since WWII. In addition, training of 21st Inf. Regt, during soft occupational duty in Japan, was apparently relatively lax. In several AARs I have read it was apparent that bazooka men were not removing safety pins from rockets prior to firing them. This prevents the striker from setting off the primer cap…thus no Monroe effect.

[Tanaka]

Originally posted by Jeff Duquette:

... In several AARs I have read it was apparent that bazooka men were not removing safety pins from rockets prior to firing them...

Ok, I follow your idea until here but this last part is a bit hard to believe... Don't know how the zooks were handed out in the American Army, but in the Portuguese one, on the late 60's early 70's the loader and the gunner endure specific training. As there was a Szook per platoon no one wanted "any" guy with the weapon, if not used properly it's back blast would do more damage to the platoon then to the enemy, specially in closed terrain like jungle and woods.

[gunnergoz]

One frequently overlooked fact about the T-34/76 is that it had a two-man turret with the commander having to carry out gun control tasks as well as "fighting" the tank through the battlefield. This meant that the TC in a '76 was busier than a one-legged man in an ass-kicking contest.

Small wonder that their TC's situational awareness was often dismal and that it was relatively easy for German tankers to get "inside the decision loop" of their Russian counterparts and so outmanouver and outfight them. Add to this the lack of radios and the frequent lack of training of crews in the '76's in the early days of the war (say to mid-'43) and one has a recipe for disaster.

CM2 will have to find a way to adequately model this unique failing of the basic T-34 design as it is easily overlooked.

[jasoncawley@ameritech.net]

A few 60mm zooks did kill T-34s in Korea, but it was quite rare. We have reports of T-34s taking dozens of hits from them, including some from the rear, and driving on. 75mm recoilless rifles also hit them in the turret sides without apparent effect.

The 3.5" zook is essentially a panzerschreck. Same caliber. They did not have any trouble KO-ing T-34s. Other ways that T-34s were taken out include 105mm HEAT. 105mm HE was used to break their tracks, before enough HEAT was available in theater. Aircraft also took out a number of them, with 5" rockets and napalm. Pershings had no trouble with them.

T-34s caused serious trouble in Korea only in the first few months of the war. ROK forces had a few hundred towed 37mm AT guns, a handful of M-8 armored cars, and thousands of 60mm bazookas. They killed very few T-34s, mostly by bazookas when they did manage to.

By the time the fighting was around the Pusan perimeter, the North Koreans were down to about a battalion's worth of tanks, which were used in penny-packets, platoon sized or less by U.S. standards. By then, the U.S. had large numbers of Pershings, Chaffees, and Sherman-76mm in the country. The NK armor still managed to cause tactical trouble occasionally, a handful spearheading mostly infantry attacks, but their days of operational impact were over.

The Chinese had a few units of T-34, and by Soviet records anyway, around 20 IS-2s as well. But the war from the time the Chinese intervened was mostly an infantry and artillery one. And "mountain infantry" style fighting is what they were best at, where they did have a definite edge at first. The Americans were too road-bound. By spring of 1951, that had mostly changed, and Ridgeway found ways to deal with them successfully. The last two years were stalemate, with occasional artillery flurries and fights for particular ridges, more like WW I really. Meanwhile peace talks went on.

[Paul Lakowski]

What is the velocity of the 75L43 & 75L48 at 1000m range ? Is it down about 120m/s?

[Jeff Duquette]

Tanaka Said: "the gunner endure specific training"

As I indicated previously that was one of the unfortunate circumstances surrounding the first ARMY units going into Korea, ala TASK FORCE SMITH. Draftee troops with little training, and used to the soft life of occupational duty in Japan were suddenly thrust into a shooting war with North Korea.

Did any Portuguese combat units see action in Korea?

[This message has been edited by Jeff Duquette (edited 04-01-2001).]

[jasoncawley@ameritech.net]

Paul's question is a fine one, and I don't know the answer directly.

I have the muzzle velocity of the L43 as about 750 m/sec. For the L48 it is marginally higher, more like 800 m/sec. In both cases with PzGr39, which is by far the most common form of AP ammo for these guns types. Against 30 degree slope, the penetration envelope at 100-500-1000-1500 meters goes 98-91-82-72 for the L43, and 106-96-85-74 for the L48, by my source.

So that is down 16%-20% for the two types (at 1 km I mean), and to more nearly even numbers. If the penetration is going like the energy, then the drop off in speed would be somewhat less than what Paul asked about. But it is more than the initial difference - the penetration of the L48 at 500 meters is slightly below that of the L43 at 100 meters, so presumably the speed is dropping on the order of 50 m/sec in 400-500 meters of flight. I'd guess down ~100 m/sec, but it is just a guess from other people's data.

Incidentally, CM gives slightly different figures for penetration, with the Pz IVG lower, the Pz IVH and StuG III about the same, and the PAK40 somewhat better than my figures. They may have been trying to account for slight gun differences (e.g. some of the Gs had L43, but that was the model that changed over) and ammo availability (maybe a bit more likelihood of PzGr40 ammo for the towed PAK e.g.).

If you go by CM estimate of the effectiveness of 60 degee armor compared to 30 degrees, then you'd expect penetration ranges as low as 500 meters for the L43 vs. the 47mm front armor of the 1942 model T-34 (and later). With more like 800-1000 meters for the L48s. The 1941 model T-34s have a little less armor, though, and armor quality issues might increase the ranges, slightly.

Incidentally, the 50mms are going to need short range shots with good ammo, or hits on the lower hull from ranges around 500 meters, even from the sides. Even the L60 ones. To most of the stuff the Germans had in the field, this baby is every bit as daunting as the Panther is to Sherman drivers, in some ways worse.

To illustrate that point, here is the mix of AFVs the Germans had available in for the Kursk battle in summer, 1943 -

Elephant - 45

Tiger I - 133

Panther A - 200

Pz IV L43+48 - 859

Pz IV L24 - 54

Pz III 75L24 - 153

Pz III 50L60 - 542

Pz III 50L42 - 109

Pz II - 107

Plus some StuG (but not yet numerous - the Pz IIIs are still there), Marder, and a few captured T-34. Overall, ~400 tanks that could kill T-34s at long range, ~1000 that could kill them at about 1 km, and another ~1000 that needed close flank shots. They faced ~2500 T-34s, plus ~1300 light tanks, and a few hundred KVs and SUs (each).

[Tanaka]

Originally posted by gunnergoz:

....CM2 will have to find a way to adequately model this unique failing of the basic T-34 design as it is easily overlooked.

I don't know about CM2, but looking into it from a large perspective, the 1 man less crew was not a bad thing... As the British learn in 40, the difficult task was not to substitute the planes, but the pilots. With armor crews the same problem arises, like for instances in late 44 and early 45 with the German Army.

I think that even today the Russian army follows this doctrine (see T-80), why do you think they do this ? One man more might not be that good in a long war (like all wars the Russian have been into)

[Tanaka]

Originally posted by Jeff Duquette:

...Did any Portuguese combat units see action in Korea?

I had hopped that you might bring something new, but instead you just repeated the other post. English is not my 1st language, but I understand it well, so I appreciate the "repeat" but was not what I had in mind...

As for question, I didn't know there was a war in Korea in late 60's early 70's,apart from the technical meaning, because even today they are at war(cease fire thing).

[Skipper]

> I think that even today the Russian army

> follows this doctrine (see T-80)

The purpose of the minimimal crew (in both cases) is to decrease volume behind the armor. Thus you get a considerably lighter tank with the same amount of armor protection. And in tanks design lighter means faster, cheaper, harder to hit, more mobile and more reliable.

However, TC+loader combo in early T-34 turrets proved to be a poor solution. T-80s use TC+gunner combo and an autoloader. This gives them a small disadvantage with the rate of fire, which soviet designers deemed to be a reasonable price to pay for all above.

[Jeff Duquette]

Paul (I suspect your joking with the 120m/s @ 1000m)

From some archive German ammunition data Rexford snail mailed to me awhile back:

75mmL48 Pzgr39

Vm = 750 m/s

V@ 100m = 738 m/s

V@ 1000m = 626 m/s

V@ 2000m = 536 m/s

From various plots I have made of some of this data velocity decay is “almost” a linear function relative to range. You could interpolate between data points above with a fair degree of accuracy if you were so inclined.

Skipper Said: However, TC+loader combo in early T-34 turrets proved to be a poor solution. T-80s use TC+gunner combo and an autoloader. This gives them a small disadvantage with the rate of fire, which soviet designers deemed to be a reasonable price to pay for all above.

Great point on turret ergonomics. Add: T34/85 has no turret basket. Any thoughts on impacts of crew performance in a tank with no turret basket?

[Jeff Duquette]

Tanaka:

Sorry to digress from the thread topic. I was referring to the original 1950-53 conflict\police action. I am honestly curious about weather Portugal provided a UN contingent to Korea, ala. Turkey, Britain, Canada, Philippines, France, etc etc. I think I read somewhere that Spain sent a battalion of Marines to Korea (can’t remember for sure on that one however).

[rexford]

German 75mm muzzle velocities were:

L43 740 m/s

L48 750 m/s

L46 792 m/s

We found data on these rounds and 75L46 APCBC round (everything included) was as long as Panther and carried a greater powder charge, which accounts for higher velocity compared to L48.

Sherman 75L40 barrel length is only a little shorter than 75L43 but muzzle velocity difference is 740 m/s vs 619 m/s. Sherman muzzle velocity so low it doesn't need muzzle brake, rounds probably shorter than PzKpfw IVG and Sherman able to hold more ammo (?).

The problem with penetration data is that T34 armor hardness is so much higher than test plate used for penetration figures that data cannot be compared.

If it tookl 3 shots to K-O T34 at 1000m what does this mean?

Crew survived first two penetrations?

First two hits bounced?

T34 turret highly angled so it is possible first two shots bounced off the side. 75mmL43 and L48 have alot of random scatter when they fire, much more than Tiger or Panther. Good idea to hold fire to minimize ammo waste.

75L43 will not penetrate T34 front hull at 1000m if tank is angled at 20° or greater.

The StuG report is interesting, and is consistent with other material in Jentz. Some commanders say 75L43 penetrates T34 at any angle at 1200m, others say T34 armor too highly angled to make hits stick.

[Paul Lakowski]

The hardness of the plate is not a problem when the t/d is low,infact at 600m/s, 400 BHN plate should offer less resistance than 300BHN plate ...according to the test results I've seen with modern ogive steel penetrators.

I worked through the penetration using my formula and 50% Ballistic limit penetration beyond 1000m on the glacis is likely for the L48 gun.

[rexford]

Bazooka hits on T34 may suffer from two factors:

1. HEAT penetration reduced by hard armor, and T34/85 armor is very hard.

2. Bazooka must overpenetrate armor by 25mm or so to do much inside tank. Early bazooka hits on PzKpfw III and IV would blow open hatches and crew would bail out, thinking gases were poisonous. Then they would jump back in.

[Paul Lakowski]

The two man crew limited the ROF of the T-34 to around 6 rounds a minute and less if the tanks in motion....The loader [gunner] had to crawl around the floor pulling up hatches to fetch the ammo and then load so the commander could fire.

German tanks in the same situation could do 10-12 rounds per minute giving them a descive advantage when they finally got ammo that could penetrate the T-34[75mm] at a decent range.