Big Guns for the T-34

There is a large category of fans of alternative history who like to install large guns into small tanks. These people don't exist only on the internet, but also among popular authors of quasi-historical publications. They sometimes even provide some kind of schematics and make grandiose projections. While modern plans have little to do with reality, tank designers many years ago worked towards very similar goals. Every army wanted to put a larger gun into its tanks. This typically happened as a result of increased requirements for tank guns. This process started very early in the USSR. The MS-1, the first Soviet mass produced tank, was built with a 37 mm Hotchkiss gun. This was far from the only weapon proposed for it. The same gun mount could have been a home for a "high power 37 mm gun" or "37 mm Rheinmetall gun". There were many cases where the proposed gun would simply not have fit into the fighting compartment. For instance, this was the case with the AT-1. The 76 mm PS-3 gun failed to enter production and took down the SPG with it. Other 76 mm guns (for instance the L-10) wouldn't fit.

The 85 mm AA gun was seen as a potential anti-tank weapon and tank gun back in the summer of 1940.

Soviet Upgrade for an American Tank

Modernization of a fighting vehicle over the course of production is a normal phenomenon. This was not the case from the very beginning, but modernization rather than creation of whole new designs was the norm by the 1920s. In Soviet practice, a good example of this is the MS-1. The first and fourth series differ significantly, and even so the full plans for improving the characteristics of the tank were not realized as it had become obsolete and did not satisfy the military's requirements even with changes. The MS-1's successor, the T-26 light tank, shows a much fuller spectrum of modernization. It started out with two turrets, one with a cannon and one with a machine gun. The first major modernization took place in 1933, and the tank that was produced at the end of its production run differed considerably from the first vehicle. Similar processes were not unusual for tank building of the era.

The first M4A2 tanks arrived in the USSR in the fall of 1942, but true mass deliveries began closer to the end of 1943. By that point the tank's armament was a bit weak.

85 mm for Dummies

 Death to German occupants!

Areas of

GERMAN TANKS

vulnerable to the 85 mm gun

Directorate of the Commander of the Armoured and Mechanized Forces of the Red Army
Military publisher of the USSR NKO, Moscow, 1944

85 mm Gun for the KV-1

 "Order for  the People's Commissariat of Tank Production of the USSR
Chelyabinsk
November 11th, 1941

In order to widely use artillery systems that are being mass produced at the factories of the People's Commissariat of Tank Production, design and install the M-30 system and the 85 mm AA gun into the KV tank. To do this:

1. Director of the Izhora factory, comrade Muzrukov, must:
1. Provide detailed blueprints for mounting the M-30 gun in the KV tank no later than November 15th and produce a prototype, install it in a turret, and send it to the Kirov factory for trials no later than December 15th.
2. Develop a draft project for installing the 85 mm AA gun in a KV tank and send to me for approval by November 20th.
3. When developing detailed blueprints for the M-30 and draft blueprints for the 85 mm gun use components that are already being produced by the Izhora factory wherever possible.
2. Chief Engineer comrade Ryzhkov and Chief of the 5th Department comrade Bulyshev at the Izhora factory are responsible for the completion of this work.
3. Chief of the Ammunition Department comrade Levshin must resolve the issue of armour piercing ammunition for the M-30 and 85 mm gun by November 20th of this year.
4. Chief of the Ammunition Department comrade Levshin is responsible for ensuring the completion of this order.

Deputy People's Commissar of Tank Production, Kotin"

Via Yuri Pasholok

Elephant Hunters

 "Characteristics of penetrative ability of guns and mines against enemy tanks
Based on combat experience and trials

1. Experimental firing against the 88 mm "Ferdinand" self propelled gun gave the following results:

A) Armour:

• Roof: 45 mm
• Rear: 80 mm
• Sides: 80 mm
• Front vertical plate: 200 mm
• Ball mount armour: 110 mm
• Driver and radio operator visor plate: 200 mm

IS-1 Variants

Development of 85 mm tank guns in the USSR began on May 5th, 1943. Multiple competing variants were developed. A new tank was being designed in parallel, and when it was finished there were two 85 mm guns available for it: the S-31 and D-5.

Thick Skin of German Beasts

German Tiger, Panther, and King Tiger tanks are some of the best known vehicles in the history of tank building and still occupy the minds of armoured vehicle enthusiasts. Their enormous size, thick armour, and long powerful weapons created a reputation of all-destroying and nearly invulnerable tanks. However, if everything is more or less clear with their size and armament, then the issue of armour is much more difficult. This is the first in a cycle dedicated to the creation of armour for the Tiger Ausf.H1, Panther of all variants, and the Tiger Ausf.B, their assembly, and trials of the armour in the USSR, USA, and Great Britain. To start, let us talk about rolled armour that the hulls and turrets of Tigers and Panthers were composed of almost fully.

How to Kill a Tiger

There were many guides on how to take out Tiger tanks printed in the Red Army. I've shown two of them here, but this one is a lot more detailed.

From Medium Assault Gun to Medium Tank Destroyer

Development of armoured vehicles in many nations proceeds in parallel. A clear example of this is the creation of German and Soviet medium SPGs. Initially, Soviet SPGs were built as tank destroyers. Later, under the influence of the German StuG III Ausf. B, the medium assault gun program was launched, which gave birth to the SU-122. By this time, the Germans had modernized the StuG III and transformed it into primarily a tank destroyer. This SPG was known as the StuG 40. In the USSR this process took longer, as there was no gun to combat German heavy tanks until the spring of 1943. That is when the SU-85 appeared, the most numerous Soviet medium SPG used in the war.

Report on King Tigers

"HQ of the Commander of Artillery of the Red Army

1st Department

September 27th, 1944

#671654

Moscow

For the Commander of Artillery of the 2nd Ukrainian Front only

During battles of the 1st Ukrainian Front, it was determined that the enemy is using the new Tiger B "King Tiger" tank in infantry-tank counterattacks. Interrogations of prisoners and study of captured  Tiger B vehicles shows that this type of tank has the following characteristics:

• Mass: 68 tons
• Length:
• With gun: 10.4 meters
• Without gun: 7.5 meters
• Width: 3.75 meters
• Height with turret: 3.07 meters
• Primary track width: 800 mm
• Secondary track width: 660 mm
• Clearance (front): 490 mm
• Clearance (rear): 510 mm
• Rear and side armour: 80 mm
• Front armour: 180 mm
• Roof armour: 40 mm
• Armament: one 88 mm gun, two machineguns, one spare machinegun
• Ammunition carried: 48 rounds

T-44 Under Fire

The T-44 proved a tough nut to crack. Neither the Soviet 85 mm gun nor the German 8.8 cm Pak 43 could penetrate the upper front plate even from 100 meters. The lower front plate could not be penetrated by the 85 mm gun either, but the 88 mm gun managed to break it off after several hits. Despite the welding giving out, the protection was much better than that of the T-34-85, comparable to the Panther.

"Firing trials against the armoured hull resulted the complete destruction of the following welding seams: 

• Upper front plate and left side
• Lower front plate and left side
• Idler carrier and sides
• Hull roof and left side

The welding seam between the hull roof and right side was destroyed by 80%.

The overall view of the hull from the front after trials is show in figure 21.

Photo 21. Overall view of the hull from the front after trials.

CAMD RF 38-11355-2909 p.31

Big Guns

"To the Chief of the 16th Department of the GAU Artillery Committee, Colonel comrade Zhevanik

I report on the work that I performed during my trip to Sverdlovsk and Chelyabinsk from May 3rd to May 28th, 1943.

1. Kalinin factory #8.

Based on directions by Lieutenant General of Artillery Hohlov, I organized work to design and produce an experimental 85 mm tank gun. To achieve this, I supplied factory #8 with a copy of the tactical-technical requirements and necessary blueprints with the aid of the GAU military representative at factory #9. I negotiated with the factory's director, comrade Fratkin, as well as the chief engineer and chief designer. Based on this meeting, comrade Fratkin gave the order on May 4th to quickly begin work on designing the gun with the aim of completing blueprints by May 10th.

T-34-85 Review

"Report on the use of the T-34 in combat during the Patriotic War in the 37th Guards Tank Regiment

1. The S-53 gun installed on the T-34 tank has a number of design drawbacks, such as:
1. When firing, the electrical firing mechanism burns out, and until the end of the battle one is forced to use the manual firing mechanism.
2. The recoil break grease nipples break after 1300-1500 shots, which then need replacing. The factory quota promises 2000 shots before replacement.
3. The DT machinegun, both in the coaxial mount and in the hull, has a very small brass catcher, and there are frequent stoppages because of it. There is enough room to make it bigger both for the coaxial and the hull machinegun.

None More Frightening than the Cat

German industry created three armoured vehicles during WWII that had a significant effect on tank building worldwide. The appearance of the Tiger made Allied tanks obsolete. The few Ferdinand SPGs that were built introduced serious changes into the Soviet tank program. The third tank was the Panther, and its influence was comparable to that of the Tiger.

The tank was a quite unpleasant surprise for the Red Army and its allies when it made its debut at Kursk. Despite its deficiencies, the Panther is a good candidate for the best German tank of the war. The Panther was superior to the Tiger in terms of armament and frontal protection, and was made in significantly higher numbers. Many tank designers were looking at the Panther when they were making the next generation of medium and heavy tanks.

ZIS-25

"To the Deputy Chief of the GAU, Lieutenant General of Artillery V.I. Hohlov

CC: Chief of the GABTU BTU, Engineer-Colonel Afonin

CC: Chairman of the NKV Technical Council, comrade Ye.A. Satel

February 27th, 1943

RE: development and production of an 85 mm tank gun for the installation into a KV tank.

In 1942, on factory #92's initiative, work on the development and production of one 85 mm tank gun began at the factory. TsAKB's further work plan, approved by the GAU, contains further development of this project and completion of a prototype. 

Factory #92 sent materials regarding this project to the Artillery Committee. The Artillery Committee requested additional materials, which were sent by factory #92. Letter #822229 dated January 7th, 1943, communicated to us via letter #118/s dated January 24th, 1943, from the NKV requested fitting 80 rounds of ammunition in the tank.

For further development of this project by the TsAKB, I ask of you to:

1. Send tactical-technical requirements to the TsAKB.
2. In order to keep track of all the latest changes to the design of the turret and fighting compartment and correctly answer questions connected with the installation of the gun system and the ammunition racks, give instructions to send the following to the TsAKB:
1. Blueprints of the KV's turret and gun mantlet.
2. Overall views of components, parts, and items necessary to determine the size of the fighting compartment given the presence of various devices and apparatuses, and also blueprints of the attachment of the 10-T telescopic sight and its control rods.
3. Give orders to arrange for a working KV tank for the TsAKB of the latest type with a gun frame, mantlet, and fully equipped fighting compartment.
4. Give orders to send one ZIS-5 gun without the barrel and breech.

Chief and Chief Designer of the TsAKB, Lieutenant-General of the Technical Forces, Grabin

Chief of the 18th Department, Renne"

CAMD RF 38-11369-103 p. 43

Panther Penetration

"Table of results of shooting at the Panther tank

Caliber	Type	Range	Armour thickness	Result	# shots	Description
14.5 ATR	BS-42	100	50	No penetration	2	40 mm deep dent in the central part of the armour
45 mm	AP	250	50	Penetration	2	Complete penetration in the rear part of the side armour. The breach is the size of the shell caliber.
	Sub-caliber	250	50	Penetration	1	Oval penetration in the central part of the side armour 20x35 mm in size.
57 mm	AP	250	45	Penetration	1	Complete penetration in the side of the turret. The breach is the size of the shell caliber.
	Sub-caliber	250	45	Penetration	1	Complete penetration in the center of the side of the turret. The breach is the size of the shell caliber. There is spalling inside around the breach. The shell lodged itself in the breach of the gun.
	AP	300	85	No penetration	1	A 52 mm deep dent formed in the center of the sloped frontal armour. A bump formed on the inside. The armour cracked.
	Sub-caliber	300	85	No penetration	1	Oval dent in the center part of the front armour 50x65 mm in size. A bump formed on the inside. The armour has a 25 mm long crack.
76 mm reg.	HEAT	250	50	Penetration	1	Complete penetration in the center of the side armour. The breach does not widen on the inner part.
76 mm div. ZIS-3	HE	250	45	Penetration	1	Complete penetration with the inside jagged. A portion of the turret armour broke off as the shell passed inside.
	AP	250	45	Penetration	1	Complete penetration of the turret armour. The entrance opening is the size of the caliber. There is spalling on the inside.
	Sub-caliber	250	45	Penetration	1	Complete penetration of the upper portion of the side of the turret the size of the shell diameter. As the shell entered, a part of the armour that was previously weakened broke off.
85 mm	AP	300	85	Penetration	1	Complete penetration in the lower sloped front armour the size of the shell diameter. The armour has a horizontal crack passing through the opening.

"

Via Valeriy Lisyutin.

Firing at Ferdinands

"Characteristics of armour penetration of cannons and effectiveness of mines on enemy tanks

Based on experience of combat and trials

1. Trials against an 88 mm SPG "Ferdinand" show the following results:
1. Armour of the SPG: roof: 45 mm, rear: 80 mm, side: 80 mm, front: 200 mm, gun mantlet: 110 mm, front hull: 200 mm.
2. Effectiveness of firing:
1. Anti-tank rifles: firing at the side armour from 80-100 meters with the BS-41 bullet penetrates 50 mm of armour forming a 20-22 mm deep indentation. Firing at the tracks can break track pins and the track links. The rifle can penetrate observation periscopes and jam the gun ball mount.

An Opponent for the Tiger

The capture of two Tiger tanks by the Red Army on January 18th, 1943, had a significant impact on Soviet tank building. Trials of one of the tanks revealed an unfortunate fact: the F-34 76 mm gun, the main weapon of Soviet tanks, could not penetrate the side. The reaction to this result was swift. Designers were tasked with developing a more powerful tank gun immediately. It was to be installed in the KV-1S heavy tank.

Heavy Trophy

The German heavy Tiger tank left a mark on tank building worldwide. Even though propaganda and memoirs are largely to blame for its fame, the Tiger did really have nearly no competition on the battlefield among the tanks of the Allies. It's not surprising that the tank was thoroughly studied in the USSR, USA, and Great Britain. This article tells the story of how Tiger tanks were studied in the USSR and what conclusions were made, as well as the use of these tanks in the Red Army.

U-20 Requirements

"Tactical-technical characteristics for the development of an experimental prototype of the oscillating part of the 85 mm AA gun on a T-34 tank chassis to create a self propelled anti-tank gun

November 7th, 1941

1. The oscillating part of the 85 mm mod. 1939 AA gun will be installed on a T-34 tank chassis (with engine) without changes.
2. The gun mount must meet the following requirements:
1. Horizontal arc: 360 degrees
2. Vertical range: from -8 to +30 degrees
3. Aiming speed from one turn of the flywheel:
1. Vertical: 1.2 degrees
2. Horizontal: 3 and 7 degrees