IS-3 Prototype Penetration Testing

"Resilience of main hull components

Part	Thickness (mm)	Plate Angle (deg)	Shell type		Angle	Impact velocity	Range (m)	Damage type
			Caliber	Type
Upper front plate	120	60	88	AP	0	965	350	No penetration
Upper front plate	120	60	122	AP	0	758	690	No penetration
Side with spaced armour	85/16	60/35	88	AP	90	982	150	No penetration
Side without spaced armour	85	60	88	AP	90	983	159	Limit of dangerous penetration
Side with spaced armour	85/16	60/35	75	Subcaliber	60	1051	100	No penetration
Side (upper belt)	100	0	75	AP	45	905	500	No penetration
Side (upper belt)	100	0	75	AP	60	720	1600	Penetration
Side (rear part)	60	0	75	AP	35	780	1500	Limit of rear plate
Bottom with spaced armour	20/30	60	75	AP	35	607	2200	Only spaced armour is penetrated
Bottom with spaced armour	20/30	60	75	AP	35	660	1900	Same

Resilience of main turret components

Part	Thickness (mm)	Angle of plate	Shell type		Impact velocity (m/s)	Range (m)	Damage type
			Caliber	Type
Turret front	175	Sphere	88	AP	967	350	Penetration less than shell caliber
2nd belt	120	51	88	AP	900	1000	Penetration within +/- 15 degrees of normal
3rd belt	90-100	58	88	AP	900	1000
4th belt	175	15	88	AP	900	1000
2nd belt	120	51	88	AP	965	350	Penetration within +/- 30 degrees of normal
3rd belt	90-100	58	88	AP	966	350
4th belt	175	15	88	AP	975	300

Figure #35: Diagram of the damage to the turret.

Recommendations on improvement of the IS-3 tank design

Hull and turret

1. Replace the sides of the hull with a single bent 75 mm thick plate of medium hardness with a 45 mm high hardness screen in the middle part, according to the attached diagram.

Figure #9: Diagram of the hull side armour.

2. Thicken the front part of the hull roof, not protected by the turret, to 45-60 mm.

3. Increase the thickness of the front of the turret to 230 mm.

4. Remove the sudden change from the fourth belt (175 mm) to the third belt (90 mm) by changing the slope of the fourth belt according to the attached diagram.

Figure #10. Diagram of the changes to the turret armour.

RGASPI 644-2-464

It's worth noting that the designers took the results of these trials seriously and upgraded the turret armour significantly,

IS-3 Visibility

"Visibility from the tank

The IS-3 tank is equipped with the following observation devices:

• Telescopic TSh-17 articulated sight
• Seven periscopic observation devices

The observation devices have the following visibility and dead zones:

1. The telescopic articulated TSh-17 sight installed to the left of the gun has:
1. Field of vision: 16 degrees
2. Magnification: 4x
3. Dead zone: 7.5 meters
2. The gunner's periscopic observation device installed on the roof to the left of the TSh-17 sight has:
1. Visibility through the device:
1. Vertical: 12 degrees
2. Horizontal: 36 degrees
   The visibility through the sight is limited by the opening in the turret.
3. Two commander's periscopic observation devices installed in the rotating tank turret hatch:
1. Visibility through the device:
1. Horizontal: 42 degrees
2. Vertical: 10 degrees
2. Visibility through the device with moving the head:
1. Horizontal: 58 degrees
2. Vertical: 20 degrees
3. Visibility through the device with rotation:
1. Horizontal: 360 degrees
2. Vertical:
1. Forward: 25 degrees
2. Right: 18 degrees
3. Back: 21 degrees
4. Left: 32 degrees
4. Dead zone:
1. Forward: 10-16 meters
2. Right: 19 meters
3. Back: 11 meters
4. Left: 7 meters
   Both of the commander's sights have identical range and dead zones. The variable dead zones in the front, rear, and right parts of the field of view are explained by the geometry of the turret and the rotating portion of the roof."

RGASPI 644-2-464

All of this data is helpfully visualized in a diagram, which also includes data for the loader and driver, who are omitted from the text description.

Heavy Tank Production, Spring-Summer 1945

"State Committee of Defense Decree #7950ss
Moscow, Kremlin
March 29th, 1945

On the modernization of the heavy IS-2 tank, the State Committee of Defense decrees that:

1. The proposal of the People's Commissar of Tank Production (comrade Malyshev) and Deputy Commander of Armoured and Motorized Forces (comrade Korobkov) to accept the IS-3 (modernized IS-2 heavy tank) tank with the following characteristics, designed by the Kirov factory in Chelyabinsk, into service.
1. Overall data, mass, and size:
1. Combat mass, tons: 46-46.5
2. Hull length: 6850 mm
3. Height to periscope top: 2450 mm
4. Full width: 3170 mm
5. Clearance: 465 mm
6. Bore axis height: 1800 mm
7. Range with main tanks: 120-150 km
2. Armour:
1. Hull: welded
2. Thickness and angle of armour plates:
1. Upper front plates: 120 mm at 55 deg
2. Lower front plate: 110 mm at 55 deg
3. Lower side: 90 mm at 0 deg
4. Upper side: 90 mm at 60 deg
5. Upper rear: 60 mm at 49 deg
6. Lower rear: 60 mm at 41 deg
7. Floor: 16-20 mm
8. Roof: 20-30 mm
9. Turret: cast with variable thickness from 75 to 250 mm, with slopes from 30 to 70 deg
3. Turret ring diameter: 1840 mm
4. Armament:
1. 122 mm D-25 gun
2. DShK AA machinegun
3. DT machinegun
4. Gun elevation: +20 degrees +/- 2 degrees
5. Gun depression: -3 degrees +/- 0.5 degrees
6. Ammunition:
1. 28 gun shells
2. 5 DShK belts
3. 12 DT magazines
4. 25 F-1 grenades
5. Observation and aiming devices:
1. Telescopic T-Sh-14 sight
2. Collimating KV-T sight
3. Prismatic MK-IV periscopes:
1. Commander (1)
2. Driver (1)
3. Loader (1)
4. Gunner (1)
6. Other characteristics are same as on the IS-2 tank.
2. The People's Commissariat of Tank Production (comrade Malyshev) and Kirov factory (comrade Zaltsmann) must correct the defects discovered in the trials of the IS-3 tank before organization of its mass production.
3. The People's Commissariat of Tank Production (comrade Malyshev) and Kirov factory (comrade Zaltsmann) must provide for production of heavy tanks and SPGs in the following amounts:

   	April	May	June
   IS-3	25	100	250
   IS-2	225	150	-
   ISU-152	100	100	100
   ISU-122	150	150	150
   Total	500	500	500

4. The People's Commissariat of Tank Production (comrade Malyshev) and factory #200 (comrade Sherbakov) must provide for production of hulls and turrets for them in the following amounts:

   	Uralmash factory			Factory #200			Total
   	April	May	June	April	May	June	April	May	June
   IS-3	30	75	100	25	90	175	55	165	275
   IS-2	60	15	-	150	90	-	210	105	-
   ISU	225	225	250	-	-	-	225	225	250
   Total	315	315	350	175	180	175	490	495	525

5. The GOKO operations bureau must review the measures taken by the NKTP for production of the IS-3 tank in 5 days.
6. The secretaries of the Chelyabinsk and Sverdlovsk VKP(b) regional committees must aid the Kirov factory, factory #200, Uralmash, and factory #255 in their execution of this decree on production of IS-3 heavy tanks.

Chair of the State Committee of Defense, I. Stalin."

RGASPI 644-2-464

World of Tanks History Section: Rifle Grenades

The range of a hand grenade is very short. In WWI, many methods were tried to solve this problem. One of those was a special rifle grenade. A cup was attached to the muzzle of a rifle, which fired a grenade with the aid of a blank cartridge. This method was not very effective: the range was barely a few hundred meters, the fragmentation effect of the grenade was weak, and there was no accuracy to speak of. Due to a low muzzle velocity, the shots had to be fired at a large upward angle. Despite poor reliability and questionable effectiveness, the idea of rifle grenades not only survived until the Great Patriotic War, but continued to evolve.

A design of a supercaliber rifle grenade.

Competition Over Nothing

At the start of the Great Patriotic War, two design bureaus worked on rifle grenades: KB-30 and A.K. Serdyuk's SKB-35. In November of 1941, grenades from both organizations were tested at the Small Arms Research Proving Grounds. Serdyuk's VPGS-41 grenade was already in service with the Red Army. The KB-30 design was experimental.

Trials showed that the VPGS-41 reliably penetrated 20 mm of armour. However, there was a significant drawback: the stabilizing fins fell off the grenade more than half the time. The testers recommended that the design should be improved and gave Serdyuk until February of 1942 to do it. By then, he had to provide a new test batch of 500 units.

Serdyuk's rifle grenade and its usage.

The KB-30 grenade, which used a small cup to fire, penetrated less armour, but proved to be a lot more stable. The army ordered ten times more grenades of this type than the other to send them to trial in combat. Since the grenade was never accepted into service, one can only assume that the results were unsatisfactory.

Meanwhile, Serdyuk's design bureau also hit a snag with their grenades. Complaints about low effectiveness, reliability, etc. poured in from the front. The designer tried to stand up for his brainchild, sending a letter to the Chair of the Artillery Committee, Major-General Hohlov on June 6th, 1942, citing production problems.

"Insufficient technical guidance and military representative control resulted in significant deviations from blueprints and technical requirements, which mostly resulted in the following: haphazard choice of materials (whatever was available), incompetent heat treatment, a lack of anti-corrosive coating, large dimensional deviations, replacement of type 41 gunpowder with VT gunpowder, etc.

I can say with certainty that no type of ammunition is built as poorly as VPGS-41.

...

The use of the VPGS-41 grenade on the front caused negative feedback, which was mostly caused by the chaos during production that I mentioned above. 

The humble ballistics of the grenade (low muzzle velocity and range) were further compromised by poor quality of manufacturing, causing torn off stabilizers, misfires, fouling (a result of using VT gunpowder instead of type 41 like in the original design), etc.

I must add that there are also such negative occurrences as a lack of well though out tactics, means of storage and transport, and no training on how to use the grenade."

Investigating the situation, high command understood that improvement in quality was not possible in 1941-1942, and the VPGS-41 along with its more powerful 42 version was removed from production.

Even well regarded specialized design bureaus had trouble with rifle grenades. What happened when amateur inventors and other design bureaus tried their luck?

From Kazan to Leningrad

In April of 1942, a letter arrived at the People's Commissariat of Defense from the deputy director of the Physical Institute of the Academy of Sciences of the USSR, B. Vule. He wrote that the institute was about to start development of finned rifle rockets. These rockets would fly along a flat trajectory to more accurately strike enemy tanks. The estimated mass of the grenade was two kilograms.

The response from GAU specialists said that the development would make sense if the trajectory of the rocket at 200 meters was lower than the height of a tank and that the dispersion at that range would be less than a square meter. Since the letters stopped there, one can assume that the Kazan physicists could not meet these requirements.

Engineer Lipkovskiy from Moscow took a mortar round as a foundation for his anti-tank grenade. His idea was rejected on the basis that it had no advantages for the VPGS-41 grenade, but the recoil could easily injure the shooter.

Another type of anti-tank rifle grenade were bottle launchers. As the name implies, they would fire bottles of incendiary fluid at the enemy. The best known model was developed by Zuckerman, and a small batch was produced in blockaded Leningrad. Other variants sent to GAU were rejected with the standard reasoning of poor accuracy.

How to Kill an Anti-Tank Rifle in Ten Shots

One of the most interesting projects was tested at the Gorohovets proving grounds in the fall of 1943. This grenade launcher consisted of a Degtyaryev anti-tank rifle converted to fire 50 mm and 82 mm mortar rounds, converted to supercaliber grenades.

"Before beginning the trials, the Gorohovets ANIOP warned the inventor comrade Starikov about the possibility that the rifle will burst due to the large weight of the mortar round in comparison to a bullet. At his instruction, the trials went ahead anyway.

...

The firing was done with a 14.5 mm Degtyaryev anti-tank rifle. It was angled at 45 degrees when firing, resting on the ground in three places (the stock and the bipod). A piece of rubber was placed under the stock to soften the shock.

At the start of the trials, a test shot was made with a stock 14.5 mm armour piercing bullet at full charge. The stability of the rifle was not impacted by the shot. 

After the test shot, a shot was made with an 82 mm fragmentation round Type B (with a movable stabilizer), with a 500 mm long rod with a full 0,035 kg load of 4/7 gunpowder. After the shot, the rifle barrel was torn apart, with the front part of the barrel found 5-6 meters in front of the rifle. The remaining part of the barrel had a 500 mm long tear."

A week later, lighter 50 mm rounds arrived at Gorohovets. Meanwhile, the rifle was repaired, with the damaged part of the barrel removed and the remainder reinforced. The muzzle brake was screwed onto a non-reinforced barrel section. This time, the rifle survived to make eight shots, which sent the rounds to a range of 500-700 meters. The muzzle brake fell off on the first shot, and each shot destroyed some more wooden elements of the AT rifle. Having expended all of his 50 mm rounds, the inventor decided to try an 82 mm one. The round travelled for 400 meters and the rifle turned into scrap: the loading mechanism and attachment of the body to the stock were destroyed.

Even though trials were not successful, they impressed the testers. In 1944, another attempt at a supercaliber weapon was made. Right at this time, an incomplete captured German grenade launcher was brought to Gorohovets, along with several rounds of ammunition.

Ivanov and Bazeyev's rifle grenade.

"In the beginning of the current year, elements and assemblies of a captured German anti-tank grenade launcher from the Ukrainian Front were delivered to the ANIOP. In addition to the elements and assemblies, several HEAT grenades were included. Since the grenade launcher was not complete, it was not possible to assemble it for trials. In addition, this type of grenade launcher was not described in informational materials, and its combat effectiveness is unknown. 

In order to study the captured weapon to obtain data suitable for domestic designs, a technical project was made and a similar grenade launcher was built. The stock and breech of a Berdan rifle were used in the design.

The few grenades present at ANIOP were disassembled to study their design, so new grenades had to be produced to test the weapon. Due to a high load on the ANIOP mechanical workshop, the grenades were not produced and the grenade launcher was not tested."

Engineer-Colonel Ivanov and proving grounds worker Bazeyev took a stock and a breech from a Berdan rifle and assembled a grenade launcher that could theoretically use German grenades. While they were working, the captured rounds were disassembled for study. There was nothing to shoot with.

The designers asked to manufacture their own grenades, but GAU decided to not waste their resources. This was 1944, not 1941, and it was the Germans' turn to hurriedly invent the next anti-tank wonder weapon.

Original article available here.

Cruiser IV: A Bit More Armour

The adoption of the Cruiser Tank Mk.III in 1938 didn't mean that the British were fully satisfied with it. Armour that was only 14 mm thick made the tank vulnerable to anything bigger than a rifle. High caliber machineguns that were one of the most popular anti-tank weapons during the Spanish Civil War made the military seriously think about improving protection. It was impossible to do anything radical with the Cruiser Tank Mk.III, since a whole new tank would be needed. It was decided to go down the road of minor modernization. The resulting tank became one of the best and longest lasting pre-war British tanks.

Local Reinforcements

Work on modernizing the Cruiser Tank Mk.III began in 1938, the same year as it was accepted into service. The Cruiser Tank A13E3 became a test lab for ideas for the new vehicle. No serious changes would be made to the hull, suspension, or engine, all of these were satisfactory to the British. Changes were confined to the armour, and applique armour at that. The only part that became thicker was the driver's hatch, increased to 28 mm.

The turret had some changes done to it. The commander's cupola became round instead of hexagonal (similar to the cupola of the Light Tank Mk.VIB). The observation device to the left of the gun mantlet was moved to the applique armour, and the four sections of front applique armour were installed parallel to the hull. The configuration of the side applique armour was similar to that used on the Cruiser Tank Mk.III*. The gap that was characteristic for field modifications disappeared.

Production of the Cruiser Tank Mk.IVA at Nuffield Mechanizations & Aero, 1940. These tanks will later be sent to Africa.

Applique armour tested on the Cruiser Tank A13E3 showed that an extra half ton of weight did not have a serious impact on the tank's performance. Of course, the extra armour was just a half-measure. As it became more and more evident that a large war was brewing up in Europe, delaying production could become more costly. In December of 1938, an order for 65 tanks was made, indexed Cruiser Tank Mk.IV. These vehicles were also called A13 Mk.II.

Since the order for new tanks surpassed the capabilities of Nuffield Mechanizations & Aero, the London Midland & Scottish Railway Company (LMS) was given a part of the order. It is worth mentioning that the railway company played an important role in British tank building. For example, the Matilda infantry tank was assembled there. With the combined efforts of Nuffield and LMS, the Cruiser Tank Mk.IV became the most produced pre-war cruiser tank.

Cruiser Tank Mk.IVA turret.

The volume of production deserves its own mention. Often, numbers of 655 and 430 tanks are quoted, but archive data shows that these numbers are overestimated. The registration numbers for tanks of this type were given out in the following ranges:

• T.7030-T.7094 (65 tanks)
• T.9096-T.9190 (95 tanks)
• T.15215-T.15294 (80 tanks)
• T.18096-T.18160 (65 tanks)

In total, the ranges add up to 305 tanks. A report received by Soviet intelligence in 1942 gives an even smaller number. According to it, 630 Cruiser Mk.I through Mk.IV tanks were made, 121 Mk.I, 170 Mk.II, 65 Mk.III, 270 Mk.IV. A comparison with registration numbers and official data regarding the production of Cruiser Tanks Mk.I, II, and III makes this data seem reliable.

Early Cruiser Tank Mk.IV. These tanks did not have extra armour of the gun mantlet.

According to the same intelligence data, most cruiser tanks were built in 1940 (454 tanks), and in 1941, only 16 Cruiser Tanks Mk.IV were assembled. This explains why early types of cruiser tanks did not receive a name (for example, the Cruiser Tank Mk.V was called "Covenanter"). By the time that the new system of titles was in place, the tanks were no longer in production.

Changes to the Cruiser Tank Mk.IV design were made soon after production began. The applique armour, as with the Cruiser Tank Mk.III*, did not apply to the gun mantlet, which remained 14 mm thick. This problem was solved with additional spaced armour that covered the gun mantlet. These tanks were the most numerous among those equipped with a Vickers Mk.VI machinegun.

Cruiser Tank Mk.IV with spaced armour on the gun mantlet.

The next change was connected with the machinegun. In 1939, the British army introduced the BESA machinegun. The new machinegun was a Czechoslovak ZB.53 heavy machinegun modifies by the Birmingham Small Arms Company (BSA). The compact machinegun that did not need water cooling was immediately adopted by the tank branch. The Cruiser Tank Mk.IV was no exception. The modification with an altered gun mantlet and a BESA machinegun was called Cruiser Tank Mk.IVA. The mantlet and observation device were attached to the main applique armour plate on the front of the turret, which now consisted of three pieces instead of four. The mass of the tank grew to 15 tons.

Early Cruiser Tank Mk.IVA in Africa, 1941. This is vehicle T.15219, the same one as was seen in the Nuffield factory photo.

A little later, a second version of the Cruiser Tank Mk.IVA appeared. The biggest change was the cast gun mantlet, much easier to manufacture, but not devoid of drawbacks like gaps that "caught" shells and bullets. Later, this gun mantlet migrated to the Covenanter and Crusader. It's important to point out that changes made to the tanks did not result in a different numbering system. For example, tanks from three of the four modifications of the tank can be found within the range T.9096-T.9190.

Late Cruiser Tank Mk.IVA, the most numerous modification.

Some sources mention a Cruiser Tank Mk.IV CS armed with a 94 mm OQF 3.7" Mk.I howitzer, the same weapon as was used on the Cruiser Tank Mk.I CS and Cruiser Tank Mk.II CS. There are, however, some doubts about its existence, as there is no information about this modification aside from a text description. There was also a commander's version of the Cruiser Tank Mk.IVA, equipped with an additional antenna on the front right part of the turret roof.

Battles on Two Continents

As of May 1940, the Cruiser Tank Mk.IV was the second in number after the Light Tank Mk.VI among British tanks. These tanks were used by nine tank regiments in the 1st and 2nd Armoured Divisions. In the middle of May of 1940, when the British Expeditionary Force was deployed in France, 65 tanks of this type were sent there. Vehicles of all modifications were used, mostly late Cruiser Tanks Mk.IV with additional gun mantlet armour. The tanks were spread out among regiments in the 2nd and 3rd Armoured Brigades.

• 2nd Armoured Brigade: 2nd Dragoon Guards Regiment, 9th Her Majesty's Own Royal Lancers Regiment, and 10th Royal Hussars Regiment.
• 3rd Armoured Brigade: 2nd, 3rd, and 5th Royal Armoured Regiments.

The vehicles used by the Royal Armoured Regiments were very heterogeneous. For example, the 3rd regiment had Cruiser Tanks Mk.III, Cruiser tanks Mk.I, and Cruiser Tanks Mk.I CS aside from Cruiser Tanks Mk.IVA.

Cruiser Tank Mk.IV from the 2nd Dragoon Guards Regiment, 1st Armoured Division, abandoned due to mechanical failure. France, May 1940.

The French Campaign turned out to be longer for the Cruiser Tank Mk.IV than for the Cruiser Tank Mk.III. Aside from battles for Abbeville and Pas-de-Calais, tanks of this type also fought in defense of Dunkirk during the evacuation, where most of the vehicles were lost. During battles in France, the Cruiser Tank Mk.IV was a worthy opponent for German medium tanks. Its armour was comparable, as both the Pz.Kpfw. III and Pz.Kpfw. IV were protected with armour designed to resist high caliber machineguns and autocannons. Anti-tank guns used by France, Germany, and Britain made this armour ineffective. The speed of German and British tanks was also comparable. However, the British cruiser tanks had very picky engines, which often caused losses.

Unlike the Cruiser Tank Mk.III, its younger brother was destined to return to Europe. In March of 1941, the 1st Armoured Brigade from the 2nd Armoured Division was sent to Greece from Egypt. It contained two regiments, 4th Her Majesty's Own Royal Hussars and the reformed after losses in France 3rd Royal Armoured. The 3rd Royal Armoured Regiment contained Cruiser Tanks Mk.IV in addition to Cruiser Tanks Mk.IIA and Cruiser Tanks Mk.IIA CS, a part of which was taken from the 5th Royal Tank Regiment.

The fate of the 1st Armoured Brigade was even sadder than that of the BEF. The attempt to stop a German invasion of Greece failed, and most tanks were lost due to mechanical failure. After defeat in the Balkans, the 3rd Royal Armoured Regiment was reformed in July of 1942, but armed with other tanks.

This tank was lost due to a broken engine. It was a part of the 1st Armoured Brigade and fought in Greece in the spring of 1941.

Unlike in Europe, the African career of the Cruiser Tank Mk.IV was long. The first tanks arrived in early 1940, when Percy Hobart's mobile division (one of the creators of the cruiser tank doctrine) was reformed into the 7th Armoured Division, also known as the "Desert Rats". By June of 1940, the division included two armoured brigades which used Light Tanks Mk.VIB and cruiser tanks, the majority of which were Cruiser Tanks Mk.IVA.

Tanks fighting in Africa had tropical modifications. Several vehicles had long boxes attached on the left side of the turret, and mounts for 2-gallon cans were added to the rear of the hull. Side skirts were also added.

Despite Italy's official entry into the war on June 10th, 1940, active combat in Africa began in September. A month later, reinforcements were sent from Britain to Egypt: the 2nd Royal Armoured Regiment from the 1st Armoured Division and the 3rd His Majesty's Own Hussars from the 2nd Armoured Division. Two more brigades from the 2nd Armoured Division arrived in January of 1941. All glory of battle with the Italians fell to another unit that came to help in October of 1940: the 7th Royal Armoured Regiment, which consisted of Matilda IIA and Matilda III infantry tanks. While Italian artillery could fight British cruiser tanks, it was powerless against Matildas.

During Operation Compass, infantry tanks from the 7th Armoured played an important part. Nevertheless, the Cruiser Tank MkIVA was still the backbone of most British tank units. This situation persisted until the landing of the German Africa Corps in Libya in February of 1941. The first victim of the Germans was the 2nd Armoured Division, a part of which was sent to Greece in March of 1941. As of early April, the division included the 3rd Armoured Brigade, consisting of the 3rd His Majesty's Own Royal Hussars Regiment as well as the 5th and 6th Royal Armoured Regiments. The Cruiser Tank MkIV was the most popular among those units, including both early and late types. The 2nd Armoured Division was defeated in battles against the German 5th Tank Regiment and the Italian 132nd Ariete Tank Division, and by April 8th, 1941, it was disbanded.

Knocked out Cruiser Mk.IVA from the 2nd Armoured Division, Africa, March 1941.

By June 1941, the career of the Cruiser Tank MkIV was coming to an end. Operation Battleaxe was the last major battle where tanks of this type were used. By that time, the 7th Armoured Division began receiving large amounts of Crusader I tanks. Arrival of the American M3 Light Tank, known as the Stuart I in the British army, spelled the end of the Cruiser Tank Mk.IV. Its firepower was equal to the British cruisers, and its armour was superior. Most importantly, it was much more reliable. Single Cruiser Mk.IVA tanks continued serving in Africa until early 1941. Vehicles on Malta served longer than the rest. At least one Cruiser Tank Mk.IVA (serial number T.18117) remained in that garrison until at least late March of 1942.

Under a Foreign Flag

The Cruiser Tank Mk.IV was the only cruiser tank included in the BEF that was massively used by the Germans. Its new masters tried it out during the French campaign of 1940. The Kreuzer Panzerkampfwagen Mk IV 744 (e) was used as it was captured, without even a new paint job. Cosmetic changes were limited to painting over the British identifying marks and addition of the Balkenkreuz. After the French Campaign, the Germans no longer used Cruiser Tanks Mk.IVA and B, at least in Western Europe.

Cruiser Tank Mk.IVA that was captured and put into battle immediately in France, June1940. The engine betrayed its new masters.

After the 1940 campaign, several tanks (up to six) made it to the proving grounds at Kummersdorf. The other tanks were spread out between training and active units. In February of 1941, 9 tanks were transferred to Beutepanzer-Kompanie (e) within Pz.Abt. (Flamm) 100. There is also information about the use of the Kreuzer Panzerkampfwagen Mk IV 744 (e) by police units.

Tanks that were used by training units were not changed significantly. Some tanks even retained British camouflage. Tanks from Pz.Abt. (Flamm) 100 were also mostly unchanged from the fall of 1940 to spring of 1941. Notek night lights were installed, the tanks were painted in a German grey, and unit markings were added. As for tanks that were sent to the front lines, that story is more interesting. The modernization was systematic: all tanks were altered in the same way.

Kreuzer Panzerkampfwagen Mk IV 744 (e) from Pz.Abt. (Flamm) 100.

First, tanks from Pz.Abt. (Flamm) 100 received new tracks, borrowed from the Pz.Kpfw.II Ausf. D1. The change might seem strange if one does not consider that the donor tank was essentially the German vision of a cruiser tank. The cause of this replacement was unknown, it was possible that the new tracks were simply longer lasting.

A bigger change compared to the original design was the addition of wooden shelves along the sides for fuel canisters, located behind the skirt armour. Holders for canisters were also added on the fenders. Front and rear mudguards were replaced with simplified ones. At the same time, the side elements of the fenders were removed.

In addition to standard lights, Notek night driving lights were added to the front and rear. The muffler was partially covered by a screen, and a mount for an unditching log was added. At least one tank from Pz.Abt. (Flamm) 100 (turret number 265) received a movable tow hook for a Renault UE trailer. Almost all Kreuzer Panzerkampfwagen Mk IV 744 (e) in Pz.Abt. (Flamm) 100 were of the later type, and only tank #142 was from the early series.

Typical Kreuzer Panzerkampfwagen Mk IV 744 (e) at the end of its career. The removed engine compartment roof indicates a broken engine.

Converted tanks were used in the first days of the Great Patriotic War. Tanks from Pz.Abt. (Flamm) 100 of the 18th Tank Division were included in the 2nd Tank Group of Army Group Center. The battalion participated in the assault on Brest Fortress and later fought in Belarus. However, the combat career of the Kreuzer Panzerkampfwagen Mk IV 744 (e) was not long. By July 11th, 1941, three weeks after combat began, the battalion no longer had a single tank of this type. Most were lost due to breakdowns.

Aside from Europe, the Cruiser Tank Mk.IVA fought under a foreign flag in North Africa. As of July 23rd, 1941, the German 5th Light Division had two Cruiser Tanks Mk.IVA. These vehicles were lost by September 12th. Aside from the Germans, the Italians used captured tanks, both as tanks and as immobile pillboxes. Unlike tanks that fought on the Eastern Front, the African trophies were not altered at all. They did not even have new markings.

Original article by Yuri Pasholok.

World of Tanks History Section: New Life for Rockets

Using a rocket against a tank is very tempting. Rockets can carry a powerful warhead and can be launched without an expensive barrel: all you need is a rail. In the 1930s, Soviet pilots were already using rockets to fire at enemy planes.

During the Great Patriotic War, an attempt was made to use rockets to destroy German tanks, but it turns out that this wasn't so simple.

Failed Trials of 1941

A report on the first day of trials held at the Sofrino proving grounds on August 6th, 1941, can be summarized in one sentence: "Since the trials were performed at night, the rockets were not found." The trials were done to determine the precision of the rockets, and it's very clear that the results did not impress the testers.

The next day was more productive, since it was possible to find the rockets. It turned out that firing and hitting are two different things. The horizontal dispersion of the rockets launched from a kilometer away reached 50 meters. It was clear that hitting a tank at this distance was not possible, but the trials had to establish the effect of a rocket on an armoured plate anyway.

The plate was placed at 200 meters, and five rockets were launched, none of which hit. Testers once again wrote about the large dispersion and moved the target to 100 metres. Here, they got lucky: one of two rockets hit the plate and left a small dent. This was enough for GAU, but its workers were specialists. Others were specialists in the field of imagination. Today, these kinds of people write books about people going back in time and changing the course of history. Since no one though of that genre yet, all they could do was flood the State Committee of Defense with letters, or even send them directly to Stalin.

Mikhail Mil's Rocket Gun

In October of 1942, engineer Mikhail Leontyevich Mil was working as an assistant for Chief Engineer Nikolai Ilyich Kamov at factory #290. The reader may recall that these two reached glory as the creators of domestic helicopters, but that was several years later. In 1942, Mil presented a proposal for an anti-tank gun that fired 82 mm RS-82 rockets.

The designer promised that one soldier was enough to operate the gun. A special device was used to ensure that he would not be harmed by the exhaust, diverting it to the side.

The mass of the launcher was 14 to 20 kilograms, depending on whether it was installed on a tripod or a heavier mount. The effective range was the same as for a regular anti-tank rifle: 100-200 meters. Mil was certain that his specially designed anti-tank rocket could penetrate even heavy armour. Another advantage of the project was that production could be quickly set up in the Urals.

Interestingly enough, Mil's project was not pure theory. In his letter, he wrote that "Since this proposal was made (August 15th, 1942) the author, with the assistance of comrade S.V. Paskhin, made and tested 3 launchers. Trials showed the need for improvements, which are being done now."

Workers of the sorting department at the Commissariat of Defense were experienced judges of proposals. This one didn't seem like lunacy, so it was forwarded to the GAU. There, specialist studied Mil's proposal in more detail and responded that "the odds of hitting a 3 meters wide and 2 meter tall target are 3.4%, which means that out of 100 rockets launched, no more than 4 will hit. Due to this fact, development of comrade Mil's proposal is not productive."

Rocket Guns and a Self Guided Mine

There were three projects for rocket guns: Mil, Mil-Paskhin, and Kamov-Korotkih. While the negative response made its way to the Urals, all three types were assembled and tested. It's not hard to predict that the trials confirmed the suspicions of the artillery specialists. The rockets missed constantly.

Despite GAU's rejection of factory #290's proposals, the engineers kept working on them on their own initiative. N.I. Kamov informed Moscow of this in 1944. He noted that the weapon is reliable and harmless to the shooter. Kamov also presented his ideas about why the rockets don't fly straight and how to improve on that.

"Since many military leaders consider having this weapon for infantry very useful, I thought about this issue and came to the following conclusions:

1. The poor precision of the weapon is caused by random chance in the formation of the rocket jet.
2. Rotating the RS-82 rocket should neutralize that factor."

Kamov was ready to keep working on his guns, but no response from GAU was found in the archives. If there was one, it was likely that GAU informed Kamov that rotating the rocket would weaken the effect of the HEAT jet. By 1944, developers of domestic rocket launchers came to this conclusion themselves.

No story about rocket anti-tank weapons would be complete without the mention of another curious design. In late November of 1942, the SPTM self-guiding anti-tank mine designed by military engineer 2nd grade Rasskazov was tested at the GABTU proving grounds. The solution was simple and creative: a rocket propelled explosive charge was attached to a wire, hung across the road. A tank that hit the wire freed a pin, which would launch the rocket and hit the side of the tank.

Trials showed that the pin doesn't work very reliably. Out of 11 launches, it failed 4 times. In other cases, the rocket shot straight into a T-34's side. The penetrative power of the rocket was tested on PzIII and Pz38(t) tanks. While imperfect, its HEAT warhead reliably penetrated 30 mm of German armour.

The rocket was sent back to correct discovered defects. Whether there were some difficulties with that or some other factors came into play is unknown. While the SPTM did not make it into the Red Army, it can be considered a precursor to modern HEAT mines.

Original article available here.

Late War Rarities

The topic of hilariously obsolete tanks popping up late in the war is one that never dries out, it seems.

CAMD RF 38-11355-2268

"Report regarding sending tanks, SPGs, or armoured cars from repair factory #105.

I report that on February 26th, 1944, the following were sent to P/p 12908

• T-26 tanks: ## 357046, 338971, 9772, 207565
• T-38 tanks: ## 202471, 202339
• BT-7 (with 76 mm howitzer): #991-32"

Note that the BT-7 with a howitzer is not called "BT-7A", like it is in many sources. In documentation it is often also called "BT-7 Artillery", but never BT-7A.

French Mega Tank

"To the Deputy People's Commissar of Defense, Lieutenant-General of the Tank Forces, comrade Fedorenko

I report that, according to interrogation of many prisoners from POW camp #74, new French heavy tanks arrived at the southern front with the following characteristics:

• Mass: 72-74 tons
• Armour: multiple layers, specially hardened using Krupp's method (thickness unknown)
• Armament: one 155 mm howitzer, one 75 mm gun, three machineguns (one AA), flamethrower with a range of 300 meters.
  Some prisoners say that an 88 mm gun is installed on the tank. In addition, a high power anti-tank rifle is allegedly also installed.
• Engine: two Renault gasoline engines (others say one Maybach)
• Crew: 5 (commander, driver, radio operator, gunner, machinegunner)
• Other information: the prisoners say that the suspension is protected with armour and that the hatches are air-tight, allowing the tank to drive into the water up to the turret."

CAMD RF 38-11355-353

T-44 Upgun

"To the Deputy Chair of the State Committee of Defense, comrade Beriya

[cut off] January 1945

The tank park of the German army consists 50% of heavy Tiger and Panther tanks. Our heavy IS tanks, ISU SPGs and SU-100 SPGs make up about 28% of our total amount of produced tanks and SPGs. The main tank of the Red Army is the T-34-85, which has difficulty fighting heavy tanks. The new T-44 medium tank produced at factory #75 in Kharkov has the same armament as the T-34-85 tank.

To improve the armament and achieve superiority in firepower for our tanks, I consider it necessary to install the 100 mm D-10T gun into this tank. It is very possible to install this gun.

Based on the above, I ask you to order the People's Commissar of Tank Production to produce an experimental prototype of a T-44 tank with a 100 mm D-10T gun to urgently begin mass production of the T-44 with this gun.

Marshal of the Armoured Forces, Fedorenko
Colonel-General of the Tank Forces, N. Biryukov