Artillery T-34 and KV

I talked about mortars on a T-34 before, but this is an even more ambitious project. A 400 mm mortar was to be installed on a T-34.

CAMD RF 38-11355-693

The mortar would be transported facing forwards, but could only fire facing to the side, with spades deployed. Otherwise, the massive recoil would destroy the T-34 chassis.

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The T-34 plan was, technically, just a backup. The main bearer of the 400 mm mortar was to be the KV-1S. The chassis weighed 37 tons. The mortar would weigh 50 tons. Just as with the T-34, the spades are present, since even the more robust KV chassis could not take that kind of recoil.

Neither project progressed past the blueprint stage.

There was another failed plan to make a KV-1 into an artillery platform, this one using Katyusha rockets. 

CAMD RF 38-11355-693

While the rockets were traditionally used for indirect fire, there were several situations where the rockets had to be aimed directly at enemy tanks, with great effect. This project was also never built.

Prototype KVs

Despite the superiority of the KV over any other tank in armour and armament in 1940, the Soviet Union did not stop developing heavy tanks. Intelligence about thick armour and high penetrating guns of the potential enemy led to bigger and better tanks being developed.

KV-3 (Objects 150, 221, 222, 223)

The first is the KV-3 (Object 150). Unlike the later tank with that same name, this was essentially a slightly better KV-1, with 90 mm of armour and an improved F-32 gun (early KV-1s had the L-11 gun). The KV-3 also had a commander's cupola. However, the thick armour increased the tank's mass to 51 tons, which was too much for the engine. Regardless, the vehicle passed trials. Only one was built before the war. It was lost in battle defending Leningrad with the 123rd Tank Brigade. This tank is also known as "first KV-3", or T-150.

KV-3 (Object 150). The only immediately apparent difference between this and the KV-1 is the presence of a commander's cupola. From Solyankin et al, Soviet Heavy Tanks 1917-1941

KV-3 (Object 221) was developed with an 85 mm gun, but was never built. KV-3 (Object 222) with the F-34 76.2 mm gun met the same fate. In 1941, an electromechanical transmission was developed, but never built. KV-3 (Object 223) was the most impressive of the lot, with up to 120 mm of sloped armour, and a 107 mm ZiS-6 gun. It was never built. However, a KV-1 with a lengthened hull was built, and artificially loaded to 70 tons, in order to see if the torsion bar suspension could handle that kind of weight. It could, but the rubber tires would have to be reinforced.

KV-3 (Object 223). Model and inside. From Solyankin et al, Soviet Heavy Tanks 1917-1941

In April of 1941, it was decided that all KV-3s needed 120 mm of armour in the front of their turret and hull.

KV-220 (Object 220)

The KV-220 was another development of the KV-1. It had unsloped turret armour plates, but a roomier turret, and an 85mm F-30 gun. Armour was improved, up to 100 mm. The tank had an improved transmission compared to the KV-1. The prototype were sent to defend Leningrad with the 124th Tank Brigade, re-equipped with a 76 mm F-32 gun. The old turret was used as a part of an artillery battery. The tank was lost in battle, later repaired, and sent to a training unit.

KV-220. From Solyankin et al, Soviet Heavy Tanks 1917-1941

KV-220 being transported by crane in the background. The seventh road wheel and fourth idler are clearly visible.

An order to assign new vehicles to the 12th Independent Training Tank Regiment. A tank model "For the Motherland", serial number 220-2, engine number 1193-03 is the KV-220 that survived. CAMD RF 3674-47417-2

KV-4 (Object 224)

At the same time, another group of engineers was developing the KV-4. The tank would have a 107 mm gun, a 45 mm gun (76.2 mm in one project), and light and heavy machine guns. Some versions were equipped with a flamethrower. The powerful engine would accelerate the KV-4 up to 51 kph, depending on the project. The armour was even greater than that of the KV-3, at up to 180 mm. The mass of the tank was up to 100 tons. Over 20 designs were proposed, some are available at the Russian Wikipedia page. The most interesting ones are Kruchenyh's design (9 crew members, 180 mm of armour, 107.7 tons), Yermolayev's design (51 kph max speed), Shashmurin's design (76 mm gun in the turret, 107 mm gun in the hull), Mihailov's design (50 kph, 180 mm of armour), and Tarapatin's design (107 mm gun turret with limited traverse). Visually interesting designs are included in this article.

Three designs of the KV-4 by Shashmurin, Tarapatin, and Fedorenko, illustrating the many unconventional shapes a KV-4 could have taken.

KV-5 (Object 225)

The KV-5 projects had the same armament and engine as the KV-4, but even more armour than most of those projects (150-170 mm).  The mass was projected to increase to 100 tons. The project was meant to be finished in October of 1941, but the start of the war interfered. Simplifications to the tank had to be made, such as replacing the stamped turret with a welded one, and a single 1200 hp engine with two 600 hp ones.

The start of the war defined the priorities of KV production.

CAMD RF 38-11355-958

"By order number 1217-503ss from May 5th, 1941, the production of tanks at the Kirov factory is outlined as follows: the primary tank for 1941 will be the KV-3, and, depending on the trials of the KV-4 and the KV-5, one of these three vehicles for 1942. 

The Chelyabinsk Tractor Factory will keep producing the KV-1 with 75 mm of armour. There is a possibility to, without radically altering the production process, to increase the protection of the tank by increasing the armour to 90 mm. 90 mm thick armour that is hardened by high frequency electric current is equivalent to 100-110 mm of armour. 

An experimental prototype of a KV tank with 90 mm of armour is being developed at the Kirov factory, (order number 1288-495ss) that uses the same configuration as the KV-1, aside from the gun. The factory tests are producing satisfactory results. 

Based on this, it is possible for the Chelyabinsk Tractor Factory to, starting with January 1st 1942, begin producing KV tanks with 90 mm of armour and 76.2 mm model 1940 guns. 

This decision will allow for:

1. Increasing the second manufacturing base for powerful tanks.
2. Production of spare parts for existing KV-1 and KV-2 tanks.

Please confirm these developments.

Marshal of the Soviet Union G. Kulik."

However, as the war went on, it became abundantly clear that heavily armoured tanks were to be replaced with fast ones, and powerful expensive new guns were not needed. The upgraded version of the KV-1, the KV-1S, had less armour, and not more. Later KVs with the numbers 6 through 12 were either KV-1 tanks with modified armament or, in the case of the KV-7, a radically different vehicle.

Ancestors of the Maus

The design of the Maus tank started way back in 1942. Before the "45" ton Tiger (that swelled up to 57 tons during development) hit the battlefield, Porsche was already developing the VK100.01(P) (first 100 ton class prototype, Porsche). The tank weighed 100 tons and had a 15 cm KwK L/40 gun. This was roughly analogous to the KV-4 and KV-5 designs the Soviets were producing a few years prior, with 120 mm of front armour. However, the process of inflation already began, as Hitler already decided to increase the mass of the tank to 120 tons.

Blueprint #3381, dated June 4th, 1942

The newer, larger, Maus (then called Typ 205) blueprint was ready on June 17th, 1942. The mass of the tank was 140 tons, while the engine remained the same. Much like in many of the KV-4 designs, a top turret was added, with a 7.5 cm KwK L/24. The armour grew to 150 mm.

Blueprint #3382, dated June 17th, 1942

The result was a bit of a mess. Krupp, rightfully, wanted to redo the turret, and Porsche the suspension. As a result, the whole thing was scrapped in July, and the PzKpfw Mauschen started development. The new Krupp turret included a 15 cm L/31 gun with a coaxial 7.5 cm L.24 gun. The mass of the tank grew to 150 tons. In response, the tank got a new 900 hp engine and four tracks. The tank looks pretty close to what we recognize as a Maus today.

Typ 205A, PzKpfw Mauschen, October 28, 1942

World of Tanks History Section: AMX 50 100 / AMX 50 120

The Second World War and its many years of occupation led to stagnation of the French tank building school. The ARL-44, planned for production in 1944, was already obsolete compared to tanks of the USSR, USA, or Germany. French engineers had to quickly develop a tank that could deal with modern war no worse than a Tiger or IS.

Compared to their colleagues from other countries, the French had less experience in building tanks. However, instead of picking apart a captured tank and copying it, they decided to experiment. The result was very interesting.

While they did not copy anything outright, the French borrowed some technology from their "inherited" German E-series documentation. The first prototype, named AMX M4, was reminiscent of the King Tiger. It had the same suspension, with interleaved road wheels and internal shock absorbers. However, it had a rear engine and transmission. The tank was never built in metal.

A decision was made that the new tank had to have a more protected turret and a more powerful 100 mm gun. The French put the gun in an oscillating turret. The turret was composed of two parts. The gun was fixed in the upper part, and has no mantlet. Vertical aiming was achieved by moving the entire top part of the turret up and down. Horizontal aiming was done by rotating the lower part of the turret. This allowed the turret to be very small, due to a lack of gun elevation mechanisms. Additionally, one crew member could be eliminated by installing an automatic loader.

The first autoloader used a revolver drum-like cassette. The cassette fit 6 rounds, which had to be refilled manually.

The new tank was indexed AMX 50 100. Aside from the new gun, it received a better suspension, 120 mm of front armour, and a 1000 hp gasoline engine. In theory, the tank was supposed to accelerate to 60 kph, but tests never managed to get it over 51 kph. Even that result was pretty good for a heavy tank.

In 1951, during continued tests of the AMX 50 100, a new 120 mm gun was developed. The model with this gun was called AMX 50 120. The tank was developed as a counter to Soviet IS-3 and T-10 tanks.

Like its predecessor, it had an oscillating turret and an autoloader. The hull was changed. The front was "piked", like the IS-3. Aside from a 120 mm gun, the turret had 7.5 mm machine guns, to combat enemy infantry. The hull was cast, which increased its durability. The increase in mass decreased maneuverability. The French wanted the tank to accelerate to 65 kph. This would have required a 1200 hp motor, but the French never managed one that could achieve more than 850 hp.

The increase in caliber had a downside. While 100 mm shells were still serviceable, manually reloading a cassette of 120 mm shells was hellish labour.

The French were proud of their new tank. They considered it as mobile as a Panther, as powerful as an IS-3, as reliable as a Sherman. Even Germany was interested in this new tank, and made a preliminary contract to buy some AMX 50 tanks.

However, if you look past the developers' optimistic views, the AMX 50's real life applications were questionable. Its mobility and autoloader would give it an edge in quick battles, but its weak armour and large size made it completely unsuited for prolonged combat.

AMX 50 never made it to mass production. Only five of these very interesting vehicles were built. Many opinions exist as to why. Some historians claim that the tank was insufficiently protected, especially against HEAT. Due to the oscillating turret, it was difficult to protect the crew against chemical weapons, or radiation. Finally, oscillating turrets were not compatible with NATO's standardization plans.

There is another version. The tank was "buried" by corrupt officials. After the Korean war, America had a surplus of tanks, which had to be sold to someone quickly. Some French military officials made a profitable deal, and France got M47 Pattons instead of AMX 50s.

Original article available here.

Soviet 107 mm Guns

Even before WWII, before the Tigers and Panthers, before the Ferdinands and Maus tanks, the rumours of the next super-armoured and super-powerful heavy tank were floating around. Whether it was the Neubaufahrzeug, B1, or some other menace from a potential enemy, the USSR had to be able to defend against it. 107 mm was the caliber of choice, perhaps due to the already available 107 mm field gun model 1910, modernized in 1930. However, even before the war, this gun was deemed not powerful enough, and a new 107 mm gun model 1940 was built. The length of the gun increased, from 38 calibers to 43. However, this was still a field gun, unsuitable for installation in a tank.

In 1941, during a phone call to Stalin, Grabin expressed the need for "a powerful tank gun, capable of penetrating armour of the tank that carries it at 1000 meters". Stalin suggested that the gun should be even more powerful than the modernized 107 mm gun. The 107 mm tank gun ZiS-6 was produced in only 38 days. Another 107 mm gun was considered, the F-42, but it was too bulky to install in even the KV-2's roomy turret. However, several parts of its aiming and loading mechanism were borrowed for the ZiS-6.

But that's not the most powerful gun of that caliber that was built. In 1938, a gun of unprecedented power was ordered. 107 mm in caliber, 70 calibers in length, capable of penetrating a 160 mm armoured plate sloped at 30 degrees, from a kilometer away! All this, at 10 rounds per minute.

Let's see how all of these guns fared.

CAMD RF 38-11355-10

The table above demonstrates calculated penetration data against an armoured plate at 1000 meters, angled at 30 degrees from horizonal. The rows that interest us are in the middle.

The 107 mm gun model 1910/30 penetrates a respectable 81 mm at this distance. Even this was enough to defeat the armour of any German tank in 1941. The upgraded model 1940 gun (M-60) penetrates a more impressive 100 mm. This is enough to take out a Tiger from the front, a whole two years before a Tiger was even built. The ZiS-6 gun lives up to its promise of being able to penetrate its own tank's armour at 1000 meters (this gun was meant for the rather beefy KV-3 tank), with 115 mm of penetration. The "107 mm high power gun (experimental)" achieves 188 mm of penetration. That's enough to pierce a Tiger tank front to back! 

There was also another 107 mm gun project, the M-75, an upgrade over the M-60, just a year after it was built. Mounted on the ML-20 carriage, it could penetrate 165 mm at 30 degrees, at 1000 meters. That one didn't make it in time for the chart above, but it exists in another document.

CAMD RF 81-12038-50

When the war started, Germany turned out to not have any super-powered monsters in its arsenal at all. Instead of making overpowered guns that could penetrate the strongest enemy armour 3 times over, the USSR focused on making cheaper guns, for lighter tanks. The KV-3, KV-4, and KV-5 programs were shut down, and the 107 mm high power guns went with them. 

Maus Discovery

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While German super-heavy wonder-weapons are typically associated with the late stages of the war, but the Maus project started way back in 1942. In 1945, when the Soviet forces were well into Germany, only two (well, one and a half) of these tanks have been completed. Here is how Stalin learned about this discovery:

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" June 19th, 1945. To the Chairman of the State Committee of Defense, Generalissimus of the Soviet Union, comrade Stalin.

I report that, on June 4th of this year, Soviet forces in Germany found two super-heavy German tanks. One of those, with a turret and a diesel motor, was located 40 km south of Berlin, in the Stammlager region. The second, with an incomplete turret and a gasoline engine, 62 km south of Berlin in the Kummersdorf region. 

These super-heavy tanks have an electrical transmission and two coaxial guns: a large caliber one (128 mm) and a 75 mm one. German engineers from the Kummersdorf tank proving grounds say that the super-heavy tanks were developed by Porsche in Stuttgart-Böblingen, and produced by Nibelungen-werke (in Austria). 

In late December 1944, both tanks were delivered to Kummersdorf for testing. From that point, one (the one with armament) was driven to Stammlager in March of this year. The provided characteristics are approximate, as both tanks were blown up, and specialists have not yet examined them. 

Marshal of Armoured Forces (Fedorenko).

Confirmed: engineer-major [illegible]"

Here is a fragment of what the specialists determined once they got to the tank, with more pictures.

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"On June 4th, 1945, in the Stammlager region, 40 km south of Berlin, a German super-heavy tank was found.

[Photo 1: tank from the side]

The tank was blown up by the Germans. The explosion and subsequent fire tore off the turret, the roof of the motor and transmission compartments, destroyed internal turret mechanisms, the motor group, control compartment, and blew out the right side.

Examination of the surviving components provided more information about the tank.

The super-heavy German tank is a tracked combat vehicle with a fully rotating turret.

[Photo 2: tank from the front]

The tank's armament consists of two coaxial 128 mm and 75 mm guns, a front machine gun, located left of the gun mantlet on the front of the turret, a rear machine gun, and a 20 mm AA machine gun on the top of the turret, to the rear."

Tiger Tactics as Observed by the Red Army

Note: The terms "Tiger" and PzVI are used interchangeably in this document. All instances of "PzVI" (except for the title) were replaced with "Tiger", since that designation would be more familiar to an Anglophone audience.

"Comments on Combat Use of the PzVI (Tiger) Tank

1. Experience on the Belgorod direction showed that "Tiger" tanks are quite vulnerable, not only to artillery, but to AT squads and tank destroyers, particularly at short range. 76 mm guns are most effective at a range of under 500 meters, especially when fired from ambushes.

Note: the 85 mm AA gun can penetrate the side from a distance of 1450 meters, and the front from 1000 meters.

2. When advancing, Tigers are used by the Germans to support infantry, and are widely used to penetrate defensive lines.
Tiger tanks fight in small groups of 5-10 units, accompanied by sappers, infantry, and artillery  (especially with the Ferdinand self propelled assault gun), submachine gunners, grenadiers, and with other tanks, as a part of the first offensive wave.

Note: Tigers are organized into Heavy Tank Battalions.

3. After a thorough artillery barrage and/or bombardment, the Tigers advance jointly with infantry, sappers, and artillery support, under the cover of aircraft. They are used to support the infantry. In nearly all cases, Tigers are followed by assault guns, with one gun per 3 Tiger tanks on average.

4. After wedging themselves in the enemy defences, Tigers use their guns to suppress far targets (machine gun nests, mortar pits, artillery) that impede the progress of infantry.

The Tigers are followed by an infantry escort. If Tigers take casualties from AT squads, the escorts move forward, and, with support from the tanks, fight them off. Meanwhile, the assault guns and infantry mortars open fire on far away targets. When the path is cleared, the tanks continue their path.

5. After breaking through the first line of defence, the Tigers continue battle in the direction of the strike. The breach made by the Tigers is used to send through light and medium tanks with infantry riders. These reinforcements are sometimes also flanked by Tigers.

6. In order to scout out the layout of the defensive lines, Tigers use terrain to hide their hull, and try to attract fire, which sometimes happens if the opposing tankers and gunners are impatient and inexperienced. Tigers open fire at spotted ambushes and artillery emplacements from 1500-2000 meters.
Tigers are sometimes accompanied by scout aircraft to correct their movements, call out targets, and inform them of incoming tanks and artillery locations.

Conclusions:

In order to successfully combat Tiger tanks, it is necessary to:
a) open fire from artillery and tanks from ranges known to be dangerous, to not fire prematurely, and reveal yourself to enemy tanks before the Tigers close in.
b) using combat experience, arrange specialized well camouflaged tank destroyer groups. Widely use ambushes, encirclements, and other methods of tank combat.
c) in order to maximize effectiveness of AT squads fighting Tigers, coordinate their actions with AT gun and mortar teams.
d) when Tiger tanks attack, they must be the first target for AT guns and tank destroyers. If the Tiger tanks are knocked out, the accompanying medium and light tanks will not continue the attack. "

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What's in a Name?

As if there weren't already enough names for the King Tiger, Tiger II, Tiger B, PzVIB, Major General Deane decides to add a brand new one. Conveniently, this document is in English, so I don't even have to translate it.

Through what was most likely a translation error, the Tiger Imperial is born.

PzKpfw II Ausf J

In the mid-1930s, the primary German armoured vehicle was the PzKpfw I. It weighed 5.5 tons and had two machine guns in a rotating turret. While it had pretty decent characteristics, the armament did not satisfy the German army. In 1934, Krupp, Henschel, and MAN received orders for a tank with a cannon. The PzKpfw II was born. In late 1935, prototypes were tested. Modifications of the PzII were produced until 1943. The PzII will be the topic of a subsequent article. For now, we will talk about one of the later modifications, the light scout Pz II Ausf J.

After the Polish campaign in 1939, Germany considered creating a light tank with more powerful armour than the Pz I and Pz II. A large amount of work was performed on this project, and a number of prototypes were developed. One of them, Pz II Ausf L "Luchs" was accepted, and mass produced until 1943.

The Ausf J was meant to be a scout vehicle, as protected as possible, but not so heavy that its maneuverability was harmed. The work was distributed between two companies. Daimler-Benz was designing the turret. MAN was designing the suspension and the hull.

The suspension was built with Kniepkamp's interleaved road wheels, which were very popular with German tank builders in those days. In an attempt to achieve maximum parts compatibility, the suspension was taken from the VK901, which, although intended as a development of the PzII, was a completely new vehicle.

Due to increased armour, the Ausf J was going to be much heavier. While keeping the same 5 road wheels, the suspension was more robust.

The tank's hull is also curious. It was made as a single part. The crew got in through hatches in the sides. The commander entered through a hatch on top of the turret.

The tank's armour was greatly strengthened. Early Pz IIs had 14.5 mm of front armour. Ausf C, D, E, and F had between 29-35 mm of armour. The Pz II Ausf J further increased that to 80 mm. This thickness led to the tank's mass being increased to 18 tons.

The heavy armour was supposed to be compensated by a more powerful engine. However, the new gasoline engine was only 10 hp more powerful than the old one, limiting the tank's maximum highway speed to 28 kph. For a scout tank, this is unacceptably low. The aforementioned Luchs could accelerate to 60 kph.

The armament remained the same: a 20 mm autocannon and a 7.92 mm machine gun. For a modernized vehicle, this was insufficient.

The tank turned out to be so incompatible with its original design that it was not mass produced. Only 22 vehicles were built. Some were sent to training schools. Five were sent to a special tank company meant to land at Malta. When the landing was cancelled, they were included in the 12th Tank Division. From August 15th, 1942, this division fought at Staraya Russa and Demyansk. Due to their thick armour, Pz II Ausf J took the role of an assault tank. There is no data on their fate. It is presumed that they were lost in battle.

Six tanks of these types were used in the summer of 1943 in France. In 1944, one of these vehicles was converted to an engineering vehicle with a 5-ton crane.

Original article available here.

Axis Guns vs German Tanks

In order to determine if it is worth using a captured tank, it must be tested against other captured tanks. This article covers tests of German armour against guns used by the Wehrmacht and the armies of Axis minors.

In the 1942 report on trials of captured, domestic, and Lend-Lease vehicles (CAMD RF 38-11355-832), which you should all be familiar with by now, a number of such tests are described.

First, the LT vz 38, or PzKpfw 38(t), shoots at the StuG III.

At 100 meters, the 37 mm shell makes a 40 mm dent, but does not penetrate. At 50 mm, the formed is the same depth. Another shot from 50 meters, this time with an uncapped shell, makes a dent only 22 mm deep. Firing at the side from 850 meters, the Pz38(t) penetrates 3 times in a row. The diameter of the hole is 40 mm, which indicates ductile armour.

Subcaliber shells are loaded. From the same 850 meters, the shell hits a 10 mm screen, and breaks up. The main 30 mm armour plate has "an insignificant scratch" on it. Firing at the 30 mm armour with no screen, the shell fails to penetrate again. The core got stuck in the armour plate. Closing in to 400 meters, and firing at the screened armour, the shell only manages to make a 2 mm dent in the main armour plate.

The Pz38(t) starts firing at the front again. From 100, 200, and 400 meters, the subcaliber shell penetrates the front of the StuG. The diameters of the hole range from 15-18 mm.

Conclusions: "The 37 mm armour piercing shell does not penetrate the front 50 mm plate from any distance. The 37 mm armour piercing shell penetrates the side 30 mm plate from 850 meters. The subcaliber 37 mm shell penetrates the front from 400 meters. The subcaliber shell does not penetrate the 30 mm side armour."

Next is another captured and re-captured tank, the S35 Somua. Its 47 mm gun faces off against a StuG.

At 100 meters, it penetrates the front. Same at 250 meters. The diameter of the holes ranges from 45-55 mm. Another shot at 250 meters does not penetrate the front, but makes a 45 mm dent. Inside, an armour fragment equal to the shell caliber was knocked out. At 400 meters, the Somua penetrates once (next to the armour plate edge) and bounces off once, after making a 25 mm dent.

Conclusions: "The 47 mm AP shell penetrates the front from up to 300 meters."

Finally, we have two honest Germans facing off: a PzIII firing at a StuG.

At 100 meters, the shell penetrates. Hole diameter is 80 mm at the entrance, 60 mm at the exit. At 250 meters, the result is the same, with 50 mm on entrance, and 45 mm on exit. At 400 meters: 60 mm and 55 mm. Another shot from 400 meters penetrates the lower armour plate. At 700 meters, the shell penetrates the front of the StuG three times, with entrance diameters of 55 mm and exit diameters of 50-60 mm. At 800 meters, the shell penetrates the front plate, and gets stuck. An armour fragment 200 mm in diameter is knocked off on the inside

Conclusions: "The 50 mm armour piercing shell, fired from the 50 mm gun on the PzIII penetrates the 50 mm armour of a StuG at 800 meters."

In this test, you can also see that the StuG's ductile armour starts spalling once hit with a lot of kinetic energy, even if it doesn't crack like the Pz38(t) did previously.

That's it for the guns tested. The conclusions describe the shell condition after impact:
"The 37 mm German shell for the Czechoslovak 37 mm gun makes a 40 mm dent in a 50 mm armour plate at 50 meters. Without a ballistic cap, it makes a dent of 22 mm. Either way, the shell is fully destroyed.
...
The 47 mm German shell for the 47 mm French gun penetrates 50 mm of armour from 100 and 250 meters. The shell is not destroyed. The tip of the shell, in most cases, retains its shape.
...
The 50 mm German shell for the 50 mm German gun penetrates 50 mm of armour from 100 meters to 800 meters. The shell is not destroyed."

Next, let's take a look at the bigger German guns, fighting bigger German tanks. First up is the PaK 43, against a Tiger II.

"Shot #21. Target: upper front plate. Distance: 400 m. Dent 360 mm by 130 mm, 90 mm deep. A 510 mm by 160 mm fragment of armour was knocked out on the inside. A 1700 mm crack formed through the existing breaches.

Shot # 23. Target: front of the turret. Distance: 400 m. The shell hit the gun sight opening. Penetration, 130 mm by 110 mm entrance, 110 mm by 90 mm exit. 150 mm by 115 mm fragment is torn off the armour. The shell exploded behind the armour.

Shot #24. Target: front of the turret. Distance: 400 m. The shell struck the side of an existing breach. A hole was formed 100 mm in radius at the entrance. 270 mm by 220 mm, 130 mm thick, fragment of armour broke off on the inside. The welding seams on the gun mount ruptured, and the gun mount flew off.

Shot #25. Target: front of turret. Distance: 400 m. The shot made an entrance breach 140 mm by 170 mm, breaking off a 40 mm by 190 mm, 35 mm deep, fragment off the rear side. The rear of the turret has a hole 70 mm by 90 mm. The following welding seams burst: left turret side and turret rear, 600 mm in length, left turret side and turret roof, 950 mm in length, turret rear and turret roof, 450 mm in length, left side of the turret and turret roof (close to front), 500 mm in length, turret front and turret roof, 800 mm in length, turret front and left turret side, 200 mm in length."

Photo #26: The front of the turret penetrated by shots #23-25

Photo #27. The rear of the turret penetrated by shot #25.

"Shot #36. Target: lower front plate. Distance: 500 m. Shot hit an area damaged by shot #20. A breach 130 mm by 75 mm was found in a fragment of the hull that fell off."

The Tiger II's own gun (the KwK 43 was just a PaK 43 in a tank) seems to have trouble with the upper glacis, but spalling finishes the job, as always. The turret, however, is easily penetrated at 400 meters.

Next is the KwK 42, firing at the same Tiger II.

"Shots #26 and 27. Ricochet from the upper front plate into the turret.

Shot #28. Target: upper front plate. Distance: 100 m. The shot hit an area weakened by previous hits. A dent 280 mm by 110 mm was formed, 80 mm deep. As a result of cracks caused by previous shots, a 1500 by 1700 fragment of the hull fell off."

"Shot #29. Target: upper front plate. Distance: 100 m. Shell type: subcaliber. A 250 mm by 80 mm dent formed, 65 mm deep. Cracking from previous hits outlined a breach 730 mm by 600 mm."

Photo #29. Effect of a 75 mm subcaliber shell fired at 100 m.

Photo #30, indicating the section of the hull that fell off after shot #28. The ricochet from shot #29 is shown on the other side of the MG ball.

The Panther, despite its high velocity gun, cannot penetrate the front of a Tiger II, even after it has been weakened by numerous hits. Shots 26-29 do not even produce spalling, and half of them fail to do any damage at all, even to the perforated and cracked armour plate.

British Heavy Tank

While GABTU staff were hanging around England, they helped themselves to any information about newly developed tanks that the British were willing to share. This is a report from them, dated January 1943.

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"Characteristics of an English Heavy Tank

Mass: 60 tons

Armour:

• a) side: 65 and 75 mm
• b) front: 110 mm

Armament: 

• a) 65 mm gun in a central turret
• b) 18-pounder gun
• c) 2 20 mm AA machine guns in rear turrets

Maximum speed: 20 mph (32 kph)

Range: 200 miles (320 km)

The tank is planned to have 4 diesel engines from the Valentine tank, 131 hp each. Total power is 524 hp. Each motor is placed in a corner of the tank. The center is free, and has a passage from the driver's compartment to the fighting compartment. Every motor has: a friction clutch, and a bevel gear and pinion connecting it to a perpendicular bar. There are two such bars, two motors per bar. The bars are solid, and are connected to the side friction clutches. There are four such clutches, and four drive wheels.

The driver has control over the engines and clutches. Engines that are knocked out are disabled by the driver. The tank is supposed to be able to move with only one working engine."

Well, this is quite something. The ability to move with only one engine out of 4 is interesting, but I doubt that a mere 131 hp meant for a 16 ton Valentine is going to get this 60 ton monster very far. Even all the engines combined, ~500 hp for a 60 ton tank isn't exactly great. The 45-ton KV had 600 hp, and it wasn't known as the world's most maneuverable tank. 

The armament is also of interest. The positioning of the armament is reminiscent of a Churchill I, with an AT gun in a turret, and a howitzer in the hull. However, I can find no mention of a 65 mm gun used by the British. Perhaps it is a typo (there are a few in the report), and it is actually a 75 mm gun. Who knows. The 18-pounder definitely exists, but Britain didn't exactly have a surplus of those in WWII, and the ones that existed were converted to 25-pounders.

Edit: Turns out that a 65 mm gun project existed. It was called the 8-pounder by the British, and was cancelled due to very little advantage over the 57 mm 6-pounder.

Overall, this is a pretty unlikely project, considering that even the British rejected multiple guns and turret schemes by 1941. 

Baryshev's Raid

Using the enemy's vehicles against them is typical in all armies of the world. This is, of course, unless the vehicle in question is obsolete, or really bad. During WWII, both the USSR and Germany actively used enemy vehicles.

The events of this article transpired on the Volhov front early in the spring of 1942. The main characters of this story are Senior Sergeant of the 3rd Company, 107 Independent Tank Battalion Nikolai Baryshev, his crew, and a PzIII.

In the period of insufficient volumes of manufacturing, the use of captured vehicles was sometimes the only way to reinforce your unit. B. A. Shalimov, the commander of the 107th Battalion, decided to collect, and, if possible, repair abandoned German tanks. Since his unit was nearly "horseless", his commanders approved of this initiative.

The 3rd Company was full of German tanks. Baryshev obtained his PzIII personally, in a very daring fashion, from right under the Germans' nose.

The tank was parked about 150 meters from German lines. The vehicle was not critically damaged. The electic gun trigger and power steering mechanisms were damaged by grenade fragments. Baryshev and his crew repaired the tank under fire, and drove away.

At the time of a localized offensive of the settlements of Venyagolovo and Shapki, located close to the river Mga, a platoon of captured PzIIIs were escorting two companies of mountain troops. Due to a lack of radios, two tanks got lost. There was a problem with radios since the start of the war. The USSR did not manufacture enough radios for their own tanks, let alone captured ones. The radios that German tanks came with were either damaged, or the crewmen did not know how to use them. It is not surprising that Baryshev's platoon had little ability to coordinate their movements.

Baryshev, after driving his PzIII through a swampy forest, attacked and helped destroy a German guard unit, crossed the river Mga, and, with infantry, held the road connecting Venyagolovo and Shapki, cutting off the German supply line. During one of the attacks, a supply depot was captured, which was fortunate for Baryshev, as he expended a large portion of his shells.

The Soviet forces spent the night of April 10th under a German artillery barrage. Baryshev was lightly injured by a shell fragment that entered through an open hatch. Infantry, which did not have the ability to hide in armour, suffered greater losses. At dawn, the infantry was joined by a ski battalion  With these new forces, a German counterattack that was launched at noon was successfully repelled. German infantry, with one tank, attempted to attack from the direction of Shapki. Thanks to Sergeant Baryshev and deputy political commissar Zakroyu, firing from a captured AT gun, the tank was destroyed. The Germans attacked three more times that day. With heavy losses, their attacks were stopped.

On April 11, the Germans brought in fresh forces, and encircled the Soviets. Out of two battalions, only 150 men remained alive.

On April 12, after an artillery barrage, the Germans began another assault. Against a handful of Soviet soldiers and one medium tank, the Germans sent six PzIIIs with an infantry escort. After several hours, it was clear that the position could not be defended for long. The Germans closed their ring around the Soviet troops. Shell fragments disabled the last radio station the skiers brought. No help was coming. Baryshev collected the 23 remaining men and led them to the front. It was very close, 5 km away, but getting there with only one tank and two dozen exhausted soldiers was going to be not just difficult, impossible. However, the Soviets had no intention of surrendering.

Sergeant Baryshev decided to deliver the infantry to a clearing at the river Mga, right across from the positions of the Red Army. After that, cover the soldiers as they were crossing the river.

The fact that the tank was German was very fortunate. When the Germans approached the clearing, Baryshev confidently directed the tank straight at them. The Soviet PzIII was mistaken for a German one. As a distraction, Baryshev made it look like he was stuck at the clearing inching forward and backward. Soviet soldiers were creeping to the water behind the tank. The Germans spotted them, but too late, and managed to fire off only a handful of shots. All but two or three Soviet soldiers crossed the river. The tank could not, the depth was too great.

The nearest crossing was a kilometer away. Baryshev headed through the forest, straight through the German lines. He drove straight past trenches, AT guns, tanks. The Germans waved to him, some even mounted the tank and started rifling through the storage bins, mistaking the Soviet equipment in them for trophies.

As Baryshev's tank turned towards the river, the soldiers hopped off. At the same time, Baryshev discovered that he was being tailed by two German tanks; the silent PzIII was deemed suspicious. In order to not be shot at by Soviet artillery, Baryshev sent two of his crewmen ahead to warn the batteries. When the real German tanks were close, Baryshev stuck a red cloth out of a hatch and drove through the river. The Germans opened fire, but ricocheted off his turret. The guns on the Soviet shore opened fire in turn. Under the cover of Soviet guns, Baryshev made it back.

Original article available here.

British Guns vs German Tanks

Since large amounts of British and American Lend-Lease vehicles were shipped to the Soviet Union, it was important to know how well they perform against German tanks. The 1942 "Report on the shooting of German tanks with AP and HE shells from tank guns" (CAMD RF 38-11355-832) tests the 40 mm QF 2-pounder gun on the Valentine MkIII.

First up for the test was the Czech LT vz 38, used by the German Wehrmacht under the designation PzKpfw 38(t).

At 250 meters, the 2-pounder penetrates the first 25 mm plate of the front armour, but does not penetrate the second. The front plate develops a crack 250 mm long. At 400 meters, it can only form a 7 mm deep dent in the first armour plate. Closing in to 200 meters, the Valentine fires at the front plate of the turret platform and penetrates. A hole is formed, 50 mm in radius. Cracks run though the first armour plate, 200 mm around the breach. 5 bolts holding the front armour plate in place are torn off. Firing again, from 600 meters, the shot forms a crack from the top to the bottom of the front armour plate. 

Moving on to the side, the first shot penetrates the turret all the way through. One hole on the left side, 55 mm entrance diameter, 70 mm exit diameter. One hole on the right side, 38 mm entrance and 38 mm exit diameter. Another shot at 600 penetrates the turret, and also the ammunition rack of the tank. 

At 800 meters, the Valentine penetrates the side of the turret, forming two cracks, 600 and 400 mm long. 10 bolts holding the armour plate on are torn off. Another shot from 800 meters penetrates the side of the turret platform, forming two 300 mm cracks, and causing spalling. 

Moving to the front of the tank again, the Valentine fires a shot at the upper sloped plate at 400 meters. A section of the armour, 300 mm by 140 mm, is broken off. Another shot at the lower sloped plate breaks off a piece 100 mm by 150 mm and penetrates the gas tank.

Conclusions: "The 40 mm AP shell does not penetrate front armour 50 (25+25) mm thick. The reason for this is poor quality of the shells. They are destroyed completely on impact.

The 30 mm side armour can be penetrated from 800-1000 meters."

That's it for the vz 38. The armour plates are overly hardened, as we've seen on the Tiger II. This causes the plates to crack, spall, and fall off. Still, the front 50 mm of armour prove to be a challenging opponent for the 2-pounder at any distance. 

Next up for testing is the StuG III. At 50 meters, the 2-pounder only forms a 20 mm deep dent in the StuG's front armour. However, at 100 meters, it manages to penetrate the upper part of the front plate. That result does not repeat, as another shot from 100 meters only makes a 25 mm deep dent. 4 shots from the side, all at 850 meters, go through.

Conclusion: "The 40 mm tank gun penetrates the side of the hull, 30 mm thick, from 850 meters. The front of the hull, 50 mm thick, is not reliably penetrable at any distance due to the poor shell quality. Upon impact, the shells shatter into small fragments."

The Valentine gets another turn, this time against a PzIII. The results are similar to the StuG. It cannot penetrate the front at 100, or even 50, meters. 

In the conclusions, the following is noted: "The British 40 mm shell, when fired at a 50 mm armour plate from 50-100 meters, makes a 20-25 mm dent and shatters. " ... "Scattering of shells from the 37 mm and 40 mm guns does not exceed the size of a StuG at 800 meters."

Quite a poor showing by the country that invented tanks in the first place! Let's see how their larger gun fares. Another test pits the 6-pounder from the Churchill MkIV against the Tiger.

"Target: turret. Armour thickness: 82 mm. Distance: 800 m. Result: penetration. Entrance hole 82 mm in diameter, exit hole, 75 mm in diameter

Target: turret. Armour thickness: 82 mm. Distance: 1000 m. Result: dent 90 mm deep, 90 mm in diameter. Inside, a 10 mm bump is formed, with a crack.

CAMD RF 38-11377-12

Target: turret. Armour thickness: 82 mm. Distance: 1000 m. Result: dent 120 mm by 80 mm, 70 mm deep. Bump on the inside.

Target: side. Armour thickness: 82 mm. Distance: 1000 m. Result: penetration, entrance hole 70 mm in diameter, exit hole 115 mm in diameter.

CAMD RF 38-11377-12

Target: side. Armour thickness: 82 mm. Distance: 625 meters. Result: penetration, breach diameter 58 mm.

Target: side. Armour thickness: 82 mm. Distance: 625 meters. Result: unsatisfactory hit on the bottom of the armour plate."

There's a comeback! Gone is the poor shell quality of the 2-pounder. Instead of shattering into dust on impact, the 6-pounder penetrates German armour at a great distance. The armour, on the other hand, is worse than what we saw on the StuG, with cracking and large diameter holes. 

American Guns vs German Tanks

The 1942 "Report on the shooting of German tanks with AP and HE shells from tank guns" contains testing of American guns against captured German tanks: the 37 mm M5 tank guns on the Lee and Stuart, and the 75 mm M3 gun on the Lee.

The first test subject is the Czech LT vz 38, also known as Pz 38(t). The first tank to shoot at it is the M3 Stuart, firing M-51 shells out of its 37 mm gun.

The first target is the front armour plate. At 50 and 100 meters, only one shell out of 5 fails to penetrate. Holes made in the armour are noticeably larger than the shell caliber (70-80 mm in one dimension). Next target is the turret platform. One shot at 400 meters, and one shot at 600, both penetrate. Next is the side of the turret, at 800 meters. Again, all penetrations. The second shot to the right side of the turret caused a crack 140 mm long. The final shot is at the front of the tank, at 100 meters. It strikes the MG, and knocks it out. 

Conclusions: "Front armour, 50 mm thick can be penetrated starting at 100 meters. Sides of the tank, 30 mm  thick, can be penetrated at 800-1000 meters."

Regrettably, the photo quality isn't fantastic, but you can see that, in the top photo, the MG ball was knocked out. The second photo shows the shells extracted from the tank. Like all American shells, they mostly retain their shape, even after penetrating armour. 

That's it for the vz 38. The armour plates are overly hardened, as we've seen on the mid-late war German vehicles. This causes the plates to crack, spall, and fall off.

Next up for testing is the StuG. The 37 mm American gun, once again, gets first dibs.

Shots at 100 meters at the front plate. All 3 go through, one shot damaging the braking mechanism. The Germans' early war armour is ductile, giving breaches not much larger than 37 mm in diameter. The next three shots are fired from 150 meters. All fail to penetrate the armour, making dents. Another shot is fired at the side, from 800 meters, penetrating the gas tank. 

The top photo shows the StuG after taking a penetrating hit from the side. The bottom photo shows the shells. Shells marked 1 were the ones that penetrated the hull. The shell marked 2 was one of the shells fired from 150 meters that did not penetrate.

It's the Lee's turn next, firing HE shells from its 75 mm gun. 

The first shot, from a distance of 800 meters, hits the front armour. The 50 mm thick plate shows no signs of damage. The 30 mm thick cover of the transmission is dented 8 mm down, and the welding seam suffers a rupture 80 cm in length. The right half of the transmission hatch is torn off. Subsequent shots are fired at the side of the StuG.

The second shot, also at 800 meters, hits a wheel, damaging it. A second shot tears off the rubber tire. Even after two direct hits, the wheel is still functional. A shot to the side leaves a negligible mark on the armour and damages the gas mask holder on the inside. A torsion bar carrier is torn off. 

Closing in to 600 meters, the Lee shoots at the radio bay. The armour plate is bent inwards 8 mm. A crack forms along the welding seam, 1.5 meters in length.   

Further shots from 600, 500, and 400 meters keep slightly bending the armour, damage 3 track links, and a roller. 

Conclusion: "The 75 mm HE shell from the M-3 Medium tank does not penetrate or destroy a StuG from 800, 600, or 400 meters."

This is it for American guns in this report. Here are the applicable conclusions:

"The 37 mm American shell, after penetrating 50 mm or armour at 100 meters, shatters into 3-5 fragments. The tip of the shell is usually intact. At 150 meters, the shell usually makes a dent 40-50 mm in a 50 mm armour plate and breaks into 3-5 fragments.

...

Scattering of shells from the 37 mm and 40 mm guns does not exceed the size of a StuG at 800 meters.

...

Of all the gun sights tested, the American gun sight on the M3 Light and M3 Medium led to the worst accuracy.  

...

Of all low caliber shells, the American 37 mm shell is of the highest quality, and provides the most penetration. "

Another report also tests the Sherman's gun against the Tiger, which I covered earlier.

The American M1A1 76 mm gun, mounted on an M18 Hellcat (serving in the Red Army under the name T-70 Ved'ma, or Witch) was tested against a Tiger II. Firing M-62 APC shells, it achieves the following results: 

"The armour piercing shell of the American 76 mm gun penetrates:

• The side of the hull at 2000 meters.
• The overtrack hull at 1500 meters.
• The turret side from 1500 meters."

Bovington: T-34 and KV-1 impressions

Just like the Americans, the British received a T-34 and a KV-1 tank for testing. Their response to the tests was radically different.

CAMD RF 38-11355-2222

"Please advise representatives of the purchasing commission in England what to do regarding building T-34 and KV tanks. If the English really want to mass produce these tanks, I would like to know what changes they make to their construction and keep track of their efforts."

Instead of merely taking the parts of the T-34 and KV like the Americans did, the British decided to produce clones of the tanks. Not surprising, given that the state of British tank production in mid-WWII was a bit delayed. The results of the tests were discussed at the "Scientific-Investigative Tank Proving Grounds" (perhaps Bovington?) on January 6th, 1944.

"Upon arriving at the proving grounds, we were invited to a meeting room where the administration of the grounds gathered, military and civilian, about 15 people. The chief of the proving grounds introduced them as the heads of various groups and departments. All of the military men were majors and lieutenant-colonels. These people had prepared questions from various areas for us.

We were asked questions regarding the construction of the vehicles, their materials, armament, usage, etc.

This report contains several questions about the armament and construction of the tanks. The following issues were also of interest to the English, asked of me outsides the office of the chief.
1. After shooting a gun of a caliber larger than 75 mm, gases exiting the barrel obscure the line of sight, and make it impossible to view your target for two seconds. To observe the path of the shell, we had to open the hatches.
Our response: this is an issue that can only be evaluated by the tank gunners themselves. In any case, a shell with a tracer is seen better than one without.

2. The gas tanks of the tank are located on both sides of the turret, which is a hazard in the fighting compartment.
Our response: we put additional gas tanks wherever possible. Perhaps you will find a better place for them.

3. The loader's seat does not fold down.
Our response: this is an issue that can be easily fixed if you so wish it.

4. Tanks do not have equipment for indirect fire.
Our response: these tanks were not built for the purpose of indirect fire.

5. Can a KV tank with a 6 inch howitzer provide indirect fire?
The question is asked knowing about the existence of such a tank in the Red Army [Note: the KV-2 matches the description of a "KV tank with a 6 inch howitzer"]. The English have known of its existence for a while. In early 1942, Major Donnington of the Artillery Depot asked about a KV armed with a 6 inch howitzer. Based on this knowledge, we answered that the tank in question is also not designed for indirect fire.

The questions asked by the English are few. As for their content, we consider 1, 4, and 5 relevant.

The first question regarding the tracer being obscured by gases is relevant, but is resolved by experience gained while using the tank. If this event occurs, then it appears that the training of our gunners is high enough that they are capable of performing effectively despite this drawback, which we think would be difficult to remove.

Questions 4 and 5 are also relevant. The question of indirect fire is asked by the English for a reason. Their officers insist that the manner of operations that their tanks carry out requires the ability to use tanks as artillery [illegible] terrain on the Italian front led them to use tanks as artillery batteries. They suppose that our T-34 and KV tanks, if mass produced, will be supplied with the necessary equipment.

Additionally, in our conversations, we have learned that:
a) the T-34 and KV vehicles will be produced for the British army. The former will be equipped with a 17-pounder, the latter with a 6 inch howitzer.
b) the tanks will be built with an improved gearbox and differential clutches.
c) the KV air pumps will be improved. [Note: the KV the British got had a defective air pump]
d) the tanks will be equipped with centrifugal air filters that will draw air from the transmission compartment. This is explained as follows: if you take air from behind the tank, it will contain dust kicked up by the tank. If you draw air from the transmission, the air purity reached is 100% ideal.
e) the welding will be performed with electrodes made from high hardness steel, which will result in welding seams being as robust as the armour plates.

English critique of the armament of our tanks:

Their opinion of our armament is good. This could not be otherwise, as their newest Centaur tanks were just recently equipped with 75 mm guns with ballistics equivalent to the American 75 mm gun on the Sherman tank. Currently, the largest caliber tank gun the English posses is the 6-pounder (57 mm). If you further recall the Churchill tank with a 2-pounder gun, you could not expect any other evaluation of our guns. The English themselves admit that arming the Churchill with a 2-pound gun was a poor idea.

The English, however, suggest that 76 mm is not enough for a KV tank, and propose to install a 6 inch howitzer, the ballistics of which were sent to NKVT earlier.

The T-34, on which they adore both the gun and the sloped front armour, is deemed to have satisfactory armament for a tank of that type. However, the English wish to outdo us and replace it with a 17 pounder gun.

Re-armament requires some modifications, and will take time, but, taking into account the manufacturing power of England and her dominions, we could very well see a T-34 with a 17-pounder gun and a KV with a 6 inch howitzer in our time. The fact that the English expect to produce our tanks is almost not hidden from us. This was established in conversations with workers of the Scientific-Investigative Tank Proving Grounds, and is backed up by other evidence. For example, when visiting an English gun factory near Liverpool, journalist [illegible] was informed that the factory is getting ready to produce 17-pound guns for T-34 tanks, that the English will soon produce."

Yuri Pasholok mocked up the following images:

Well, this is quite unexpected. As we all know, the British decided to go with American tanks, but put a 17-pounder into the Sherman and M10 anyway. This isn't exactly unprecedented in international tank building.  The T-34 itself is a distant relative of the work of American engineer Christie. The Soviets produced a large amount of T-26 tanks based on Vickers 6-ton tanks. The German PzI was also heavily influenced by the British Carden Loyd tankette design.

Let's take a look at the tanks themselves. The T-34 is no stranger to having large guns fitted into its turret, but what about the KV? The KV-2's 152 mm gun required a much larger turret. The British were going to have a hard time with a small KV turret, if not due to the turret ring (the KV-1 and KV-2 have the same turret ring), then to the gases and crampedness that such a contraption would introduce. The British are no strangers to cramped designs (I still wonder how they fit three people into some modifications of the Valentine turret), and the gas problem would be solved by an open-top turret. Perhaps this is why they were asking about indirect fire.

The Soviets, in a similar move, fitted the KV-1 with a 122 mm U-11 howitzer, designating this prototype KV-9 in 1942. It was not mass produced. By 1943, they arrived at the same decision as the British: 76 mm is not enough for a heavy tank, considering that the T-34 carried the same caliber gun. While the replacement heavy IS tank had a 122 mm gun, some proposed versions had a 152 mm howitzer.

Q&A

To give people an easier way of contacting me than the comments, I've created an email address specifically for that sort of thing: tankarchives@gmail.com

And since I have an email for the blog, I might as well get some use out of it. Send in your questions! Got a document you want translated? Want to know a little more about a cool tank? Need something clarified? Email me and find out! Questions will be answered as a part of an article on this blog. Probably weekly, but it depends on the rate they come in at. Really interesting questions might deserve an article of their own!

Please keep all questions relevant to tanks, or at least military history.

Aberdeen: Long Term Influence

Two previous articles described the initial impression of the T-34 and KV-1 shipped to Aberdeen, and the response of the officers to the test results. Here is the lasting impact that these tanks had on American tank building practices.

"Second report on the new American T23, T25, and T26 tanks

Two months have passed since the first report on new American tanks. Since then, I have personally familiarized myself with them on the Aberdeen Proving Grounds. I was allowed to drive them, and was given a large amount of information on the characteristics and technical details. The latter allows me to make more or less final conclusions.

All new tanks (including experimental T20 and T20E1 tanks, which were experimental and transitional models) are very obviously inspired by European models in their overall form, silhouette, and other elements. This, undoubtedly, was caused as much by isolated American experience as a delayed reaction to samples of modern tanks available to them, including our and German tanks.

Our tanks' traits can be found in many new American vehicles, especially in the hull shape, turret, chassis (suspension, leading wheel location, track construction).

American officers, including officers at Aberdeen, insist that samples of Soviet tanks (KV and T-34) that arrived in 1942 were the basis for newly developed tanks, especially the T25 and T26. The main idea of these tank programs is that new American tanks must catch up to European tanks in technical and combat qualities, such as firepower, reliability, and armour protection. "

CAMD RF 38-11355-2222

One very notable contribution to American tank development these Soviet tanks made was the idea of torsion bars. Of course, the German PzIII also had torsion bars, but the first captured PzIIIs did not arrive in America until after this report was compiled.

The British, on the other hand, went for a much more direct approach, which will be covered in a later article.

For the Record

As of today, I will periodically be writing articles for the World of Tanks related blog For the Record. These articles will have to do with proposed Soviet tanks that are not included in the game, and will theorize about their potential stats and tiers and such.

Not to worry, these articles will not replace this blog. Even though there is a little overlap, For the Record remains about online tanks, and Archive Awareness remains about historical tanks. My rate of contribution to this blog (nearly one article per day, I should really pace myself) will also not decrease.

Aberdeen: British Intelligence Bulletin #78

Along with KV-1 and T-34 tanks for testing, a number of engineers and officers were sent. They, of course, wrote many reports on their experiences. This one was written by Engineer-Captain V. Prishelenko in October of 1943.

"From the materials of the [Aberdeen] proving grounds library, a certain piece grabbed my attention: "Bulletin of the British Intelligence #78, January 7, 1943". I was only allowed to view handwritten excerpts, provided to me by Lieutenant Clime. The bulletin is composed of documents captured in North Africa and prisoner interrogations. The content of the bulletin was summarized to me as:

...During the war in Finland, the Russians tested all new armament, especially tanks. Several of the tanks were found insufficient for modern war, and, with Russian energy and persistence, work on their successors began...
...Possessing talented engineers and a solid industry, KV and T-34 tanks were designed and mass produced in a very short amount of time...
...Only thanks to Hitler's foresight, and the sudden attack on Russia, were the Russians forced to start a war with obsolete equipment. Manufacturers did not gain proficiency with new tanks, crews were not trained, the armies were demoralized, the rear and supply lines disorganized. The German attacks were successful regardless of what types of tanks opposed them...
...During the war, the Russians managed to start mass producing T-34 and KV tanks. By the winter campaign in 1943 they had the advantage on all fronts. The T-34 has wonderful combat characteristics: it is fast, maneuverable, has excellent armour and armament...
...After a series of engagements against T-34s and KVs, it was made clear that the tanks are superior to German ones, and German tactics were changed accordingly. Every effort was made to avoid engagement unless a numeric advantage (on the side of the Germans) existed.

Based on this information, a comparison with the data obtained at Aberdeen convinces more and more officers that the tanks sent to them were not new, and most likely were sent after capital repairs. Additionally, they are convinced that newer vehicles are far superior, and have nothing in common with those currently at Aberdeen."

CAMD RF 38-11355-1712

The officers were right. American tests made a number of grievous errors (forgetting to oil up or clean an air filter, for instance). The tanks were several years old. The KV-1 (#11302) was made in 1942 and shipped to the Americans before Kirov workers had time to install pump screens. The T-34 was a Model 1941, based on the photographs of the museum exhibit and descriptions of its components. Two years of a brutal war wouldn't be kind to any tank. Another KV-1, shipped to the British (#11306) was previously based in Kubinka, and not as a museum exhibit. Old equipment and improper maintenance doesn't exactly make for tests that demonstrate the best characteristics of any tank.

Aberdeen: T-34 and KV-1 Test

In 1943, a T-34 and a KV-1 (the #11302 mentioned earlier) were sent to the Aberdeen proving grounds in the United States to undergo testing, and see what technical solutions from these tanks can be of use to the Americans, and what can be done to improve their designs. While the report from these tests is not widely available, another document is: a translation of the summary of the tests obtained by a GRU agent at Aberdeen. This text, especially when taken out of context, provides a very scathing, and generally incorrect view of T-34 and KV tanks. Here are a collection of documents elaborating on this information.

"Comments on the evaluation of T-34 and KV tanks by workers of the Aberdeen proving grounds in the USA, representatives of companies, officers, and commission members.

I. Tank condition

According to information received from the Americans, the T-34, after traveling 343 km, was disabled by the breakdown of the V-2 diesel engine. The Americans are of the opinion that this was caused by a poor air filter on the diesel engine.

The T-34 sent to America had an air filter of the "Pomon" type. This filter was installed on T-34 and BT tanks. If properly cleaned and supplied with oil (in exceptionally dusty environments, this must be done once every 2-3 hours), the Pomon filter guarantees normal engine operation with 79.6% air purity at air dustiness of 1 gram per cubic meter. The filter at Aberdeen was not cleaned [Note: the filter was also not oiled. The Americans wonder why the filter is called "oily" by the Soviets in their impressions], which led to uncharacteristic engine wear.

Starting with 1942, all T-34 tanks have an improved Cyclone filter, which provides 99.4% air purity at air dustiness of 1 gram per cubic meter. This filter also needs cleaning and oiling every 3-4 hours.

IS tanks in development will have an improved air filter, providing 100% air purity at air dustiness of 3 grams per cubic meter, and can operate without cleaning for 8 hours. This filter is designated "Multicyclone".

II. Armour

The Americans insist that the T-34 and KV tanks' plates are hardened shallowly, and most of the armour is soft steel. They suggest that we change the hardening technology, which will increase the armour's resistance to impacts. This opinion has no basis in reality, and was likely caused by poor analysis of the armour.

The armour of the sent T-34 tank consisted of 8S steel. All T-34s are armoured this way. This steel is hardened to high hardness (2.8-3.15 mm on the Brinell scale). The KV tank's armour was medium hardness (3.35-3.6 mm on the Brinell scale).

The Americans take the same approach as us, hardening armour of medium thickness to high hardness and armour over 40 mm thick to medium hardness. Our armour provides greater resistance to impact compared to American armour.

German heavy tanks have armour of medium hardness.

Currently, we are in the process of producing high hardness armour for IS tanks.

Perhaps, when commenting on the tanks' armour, the Americans meant that heavy tanks should have armour of high hardness.

III. Hull.

The Americans found that the tank takes on water when crossing rivers, and the hatches leak during rain. The hulls of our tanks are sufficiently watertight to cross rivers. However, the top hatches are insufficiently watertight.

IV. Turret.

The Americans consider the crampedness of our turrets a weakness. The T-34 we sent had a welded turret. New cast turrets are roomier than old welded turrets. New IS and T-43 tanks have larger turrets, due to the enlarged turret ring. The electric turret rotation mechanisms are indeed insufficiently reliable. A hydraulic turret rotation mechanism is currently in development, similar to American ones. This mechanism is very reliable and comfortable to use.

V. Armament.

It is necessary to admit that the muzzle velocity of our medium tank gun F-34 is insufficient, and is lower than that of the American 3" gun. However, the muzzle velocity of the American 75 mm gun on the M3 Medium and M4A2 tanks is also insufficient.

VI. Tracks.

During testing at Aberdeen, tracks of the T-34 tore. The track pins, instead of being guided by the guide, get caught on it and bend. This could potentially be caused by an insufficiently wide guide, or defects of the track metal. On currently produced T-34s, tracks are of much higher quality, the guide has been lengthened, and there are additional guides on the sides of the hull.

VII. Suspension.

The Americans do not like our spring suspension, based on their work with Christie tanks. [Note: the impressions of the suspension are from Christie tanks only, since the T-34 only traveled a very limited distance under the Americans' supervision. The suspension of the T-34 was different from the suspension of Christie or BT tanks]. We consider the reliability of the T-34's suspension adequate, but the T-43 is being developed with a torsion bar suspension.

VIII. Engine.

The T-34 tank has a 15 hp ST-700 electric starter. The KV has two 6 hp starters, 12 hp in total. Currently, both the KV and T-34 are built with a ST-700 starter.
A high power tank starter was first developed here. The Americans have much weaker starters. For some reason, they evaluate our starters as weak.
The ST-700 starter has a series of defects, making its reliability unsatisfactory to us. The IS tank is being developed with an electro-inertial starter of higher reliability.

IX. Transmission.

The KV and T-34 transmissions were a result of continued development of the Christie transmission. This transmission is currently obsolete.

The Americans have a poor opinion of the KV and T-34 gearboxes. They assumed that we copied their A-23 gearbox that was built 15-20 years ago by an American company. This same company built gearboxes for Christie tanks in 1929-1930.

The T-34 and KV gearboxes use a cross-bar and a bevel gear and pinion, transmitting the rotation from the motor. Perhaps the blueprints for our gearbox are similar to the A-23 ones.

Currently, a superior gearbox is used on the KV with 8 speeds (the one sent to the Americans had 5). T-34s built by the Kirov and #174 factories use a new 5-speed gearbox (the one sent to the Americans had 4). Quality of the gears in the gearbox is significantly increased.

X. Friction clutch

The Americans consider friction clutches obsolete. Apparently, even American tank companies no longer use them. They suggest that we replace them with double differentials, like they have on their tanks.

We also consider friction clutches obsolete. IS tanks are being developed with a planet gear, which makes the tank more maneuverable and reliable. All further transmission related work is aimed at transmissions of the planet gear type. This transmission is superior to the American one, which consists of a gearbox of the tractor-automobile type and a double differential.

Additionally, American tractors still use friction clutches. For example, these can be found on American Alice-Chalmers, Caterpillar, and International tanks currently being supplied to the USSR.

As for friction clutches on the KV and T-34, they work reliably, provided they are taken care of.

XI. Overall impressions.

The Americans remark that the tank is produced crudely, absent-mindedly, and with undeveloped technology of certain parts and devices. Significant progress has been made in upgrading the quality of produced tanks. However, mechanisms of American tanks are superior to domestic ones in cosmetic finish and performance.

Overall, Americans comment that their tanks are superior in maneuverability, firepower, speed, ease of use and maintenance, and reliability of construction. While American tanks are simpler to use, but ours have superior combat performance. The combination of armour, armament, and maneuverability is significantly more optimal than the Americans', which is proven by combat application."

CAMD RF 38-11355-1712

Since the above commentary makes it seem like the Americans hated everything about the T-34 and KV, here are the good parts they found:

"The shape of the tanks is loved by all, without exception. The T-34 is especially favoured. Consensus is that the T-34's shape is the best of all vehicles known in America.
...
Ammunition rack placement is very well liked.
...
The F-34 gun is very good. It is simple, reliable, and easy to service.
...
Consensus: the gun sights are the best in the world. Incomparable to any currently known worldwide or currently developed in America.
...
The Americans love the idea of steel tracks.
...
The suspension on the KV is excellent.
...
The diesel engine is light and excellent. The idea of using diesel engines has previously come up, but the Navy uses all diesel motors produced in the USA, and therefore the Army lacks the ability to use diesel tanks.
...
Both of our tanks can deal with sloping terrain better than any American tank.
...
Small size of radio stations and their placement inside the tank is good.
...
...overall tank construction is well though out...
"

Additionally, from the "Minutes of the meeting on the question of the evaluation of T-34 and KV tanks by Americans", CAMD RF 38-11355-360

"Major-General Ogurtsov speaks:
"The Americans provide incorrect data for muzzle velocity of the guns...they claim that their gun has Vo of 5700 ft/sec, or 1730 m/sec, which seems very unlikely, even given all of its advantages.""

You may notice that the T-43 is mentioned a number of times in this report. Development of the T-43 was cancelled, but many solutions from the project were used on other tanks, such as the T-34-85 and T-44.

By the way, if you ever do come across a full report, give me a shout. I'm very interested in reading it. You'll know it when you see it, it's 650 pages.