Local Procurement

"HQ of the Northern Group of the Transcaucasian Front ABTU

#0421

September 10th, 1942

To: Deputy Commander of Artillery of the Northern Group of the Transcaucasian Front

CC: Deputy Commander of the Automotive and Armoured Forces of the Transcaucasian Front, Commander of Forces of the Northern Group of the Transcaucasian Front, Members of the Military Council

On September 8th, 1942, the commander of the 563rd Independent Tank Battalion performed experimental trials of 50 mm domestic mortar shells fired from the 50 mm mortar installed on British MK-3 tanks. 

Katyusha Effectiveness

"Information

Enemy soldiers on our artillery and mortars (based on interrogations of POWs, journals and letters of German and Hungarian troops)

POW Unteroffizier Franz Georg Lamus (222nd Infantry Regiment, 1st battalion, 4th company) says the following on the power of Russian weapons:

"Russia has many weapons. There are powerful airplanes. This goes against the stories were were told that the Red Army is poor and has nothing. The Stalinorgel (Katyusha) has the greatest effect on troops. When the mortar fires 42 shots everything living in the vicinity of the explosions burns. The sound of the explosions also has a negative effect on the morale of troops."

Turret Mortars

Rockets aren't the only way to boost the KV's firepower!

"Description of the KV tank mortar

In order to increase the firepower of the tank, I think it is conceivable to install a mortar system on the turret, consisting of two pairs of specially designed mortars. These mortars can be used for creating smokescreens or other tasks. Installing these mortars will not require any special modifications, and can be done on both welded and cast turrets.

Description

1. The mortars are paired to provide higher density of fire.
2. A special clutch allows for loading without leaving the turret.
3. The angle of elevation is constant. Changing range is done by changing the amount of gas vented from the launcher, controlled by a valve.
4. The lower (and side) carrier is rigid.
5. A shot is performed by pressing a trigger type mechanism or another device, controlled by the gunner or commander.
6. Horizontal aiming is performed using the tank sights, with which the mortars are aligned.
7. Vertical aiming is performed by the loader using the gas valve. The mortars are positioned such that the two shells will land in a fork of the desired size. Gases are vented externally.
8. The mortar is simple and easy to manufacture.
9. The mortar fires standard mortar shells.

Individual design elements

1. The clutch should allow the shell to fly straight, and, at the same time, allow for loading from within the turret. Three return springs allow the clutch to return to its initial position after loading.
2. The gas valve can be of any design, including the screw type, shown in the sketch.
3. The trigger device can be done like on the 50 mm mod. 1936 mortar. The trigger will fire two barrels simultaneously. Make the trigger a lever type, with a flexible shaft, on the wall next to the gunner or commander.

Other design issues are trivial and will be resolved during the production process.

July 3rd, 1942

Politruk G.E. Vlasenko"

CAMD RF 38-11355-340

Shipping Karl Gerats

Seven self propelled heavy mortars named "Karl Gerat" (Karl device) were built by Germany during WWII. Obviously, as the war went on, the Soviets captured a number of them that operated on the Eastern Front.

CAMD RF 81-12038-727

"In the sector where the 4th Artillery Brigade is located, near the city of Uterborg, there are three 600 mm SPGs, numbered 1, 4, and 6, two of which are in the forest, and one in a destroyed hangar. These SPGs are of great interest to the GAU, and should be delivered to the USSR for testing. Determine the suitability of their delivery to the closest railroad station, what needs to be done in order to transport them, what train cars are necessary. Deliver a report no later than November 1st of this year."

And here is the response:

CAMD RF 81-12038-727

"I report that, out of the three 600 mm SPGs found 3 km north of Utenborg, only #6 can be restored. Others have serious damage to them, and completely non-functional motor groups. These SPGs weigh about 200 tons, so their delivery to the closest railroad station (Grune, 1.5 km) and subsequent loading is only possible if they are disassembled into the following components: barrel, recoil mechanism, control and aiming mechanisms, engine, tracks. The hull needs to be cut into pieces with a blowtorch and shipped separately due to its large weight (over 100 tons). In order to dismantle these SPGs, we need a special brigade with two powerful tractors, blowtorch, movable crane that can lift at least 20 tons, and special equipment for disassembly. 

For loading one SPG, the following are required:

• Barrel: one platform, 50 tons
• Recoil mechanisms: one platform, 20 tons
• Engine: one platform, 20 tons
• Tracks: one platform, 20 tons
• Hull: 5 platforms, 50 tons
• Two vehicles for transporting the barrel: 2 platforms, 20 tons
• 1 shell for the SPG: one covered train car, 20 tons

Total: 6 50 ton platforms, 5 20 ton platforms, 1 20 ton covered train car.

Assign the organization of the transport of these SPGs to engineer-colonel comrade Alekseyev."

SPG #6 "Ziu" can be seen in the Kubinka museum with the gun and markings from #1 "Adam". 

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.

CAMD RF 38-11355-693

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.

Artillery T-34

Previously, I wrote about an 85 mm gun installed in a T-34-76, but it turns out that 85 mm wasn't the largest caliber intended for the tank. The Directorate of Mortar Armament wanted to install 120 and 240 mm guns!

CAMD RF 38-11355-190

"NII #13 sent you a schematic of a 120 mm mortar to be installed in a T-34 tank. In the same letter, the Institute requests a T-34 tank to test the mortar in. Additionally, the Special Construction Bureau of the Uhtomsk factory requests blueprints of the T-34 and a T-34 tank to develop and test a 240 mm mortar for it.

Please respond with the decisions made and orders issued regarding these letters."

Yuri Pasholok further writes that the 120 mm mortar was to be placed in place of the F-34, using the same recoil mechanisms. 

Another project involves a 152 mm mortar in the T-34.

CAMD RF 38-11355-190

"1. The 152 mm mortar in a T-34 is intended to combat enemy infantry, positioned behind cover, hardpoints, or ground-wood fortifications of the enemy. 

2. Combat and tactical characteristics of the 152 mm mortar installed in a T-34:

a) maximum range: 1200 meters

b) minimum range: at most 300 meters

c) rate of fire: 2-3 RPM

d) number of charges: 1

3. The ammo rack must fit at least 25 shells.

4. The accuracy must provide the following groupings at 500-600 meters:

1) 1/100 forward and backward

2) 1/200 side to side

5. The artillery system must provide:

a) convenience during loading, aiming, firing, and unloading.

b) convenience during disassembly, assembly, and cleaning.

6. A maintenance kit must be developed for this system, as well as cases for it.

7. The aiming sight must be from an existing tank artillery system.

8. The sight must provide:

a) safety and convenience for the gunner.

b) reliability of its attachment and calibration during firing.

c) ability to aim the mortar in full rotation. 

d) the ability to check your line of fire in field conditions without complicated devices.

9. In development of this system, use the following:

a) barrel with a breach and firing mechanism from the 152 mortar model 1931. The propellant charge must be recalculated to provide (with one charge) firing distances from 300 to 1200 meters.

b) anti-recoil mechanisms, and mechanisms of horizontal and vertical aiming currently used on the T-34.

c) use the existing shell from the 152 mm mortar.

10. The artillery system must be serviced by no more than two crew members."

The model 1931 mortar was previously used in the SU-5 SPG, but the T-26 chassis was deemed too weak for a gun of that caliber. It seems that the T-34 chassis was an answer to the artillery engineers' needs, but the only mass produced artillery piece to ever arise from that was the SU-122, an M-30 howitzer in a turretless hull.