Armoured Confusion: Mid-war

The history of Soviet wartime armoured vehicles bore several misconceptions. There are many reasons for this. A number of myths came from a lack of information. Sometimes historians' own guesses that had little to do with reality were interpreted as fact. Unfortunately, the authors of some myths are still considered experts to this day and these exercises in fiction are still cited as fact. Initially the author planned on two articles dedicated to misconceptions about the Great Patriotic War, but there were too many misconceptions for 1942-1943, and so the second article won't be the last.

Howitzer KV

So called artillery tanks, or support tanks, appeared in the mid-1920s. The British pioneered the concept, equipping their Medium Tanks Mk.I and Mk.II with 94 mm howitzers. Similar tanks were also built in other countries. The USSR was no exception. The first work on artillery tanks in the USSR began in the early 1930s. The BT-7 Artillery was the best known vehicle of this type. The KV-2 can also be placed into the artillery tank category, with some leeway. The artillery tank concept was rejected by the USSR before the start of WWII. Nevertheless, the KV-9 was designed in early 1942, a tank that fully fit into the category of support tanks.

KV-9 Rejection

"According to the resolution of the GAU KA chief, Colonel-General of Artillery, comrade Yakovlev, I report the conclusion of the GAU Artillery Committee on the 122 mm U-11 howitzer in the KV-9 tank.

1. The report given to the commission is not full. We have yet to establish the accuracy and expected deviations, recoil velocity curves (due to new recoil mechanisms, different from the stock 122 mm mod. 1938 howitzer), establishing the ballistics when firing AP shells, and testing penetration with stock shells.
2. The rate of fire, range, accuracy, ammunition capacity, and ease of use of the 122 mm howitzer are inferior to the 76 mm tank gun.
   As for the penetration of 110 mm of cast KV turret armour when firing a 25.2 kg shell at a muzzle velocity of 525-573 m/s at 100 meters, calculations show that firing at this velocity is unacceptable, as the pressure in the barrel reaches 3500-4000 kg/cm^2. Due to the screw breech, it is not possible to increase the pressure in the barrel. The pressure of 2350 kg/cm^2 must be maintained, and this would require a charge that provides a muzzle velocity of 476 m/s or use the first charge of the M-30 howitzer, providing a velocity of only 432 m/s. In either case, the penetration of the AP shell will be less than the 76 mm gun. The only advantage of the M-30 howitzer in a KV-9 instead of an F-34 gun is the improved HE performance.
3. As the 76 mm gun adequately deals with all tasks required of tank artillery, using a 122 mm howitzer in a KV tank is excessive.
4. The installation of a 122 mm howitzer in a KV tank is initiated by the manufacturer as a reserve in the event of a shortage of 76 mm tank guns. From this point of view, it is reasonable to complete trials, after which a finished prototype and blueprints for it will be developed, according to commission conclusions. 

Additional trials of 80 shots are scheduled at the Nizhniy Tagil artillery proving grounds. I ask for you to order the KV-9 tank with a U-11 howitzer shipped to Nizhniy Tagil for these trials. Notify the Artillery Committee when the tank is shipped so that we can send a representative to the proving grounds."

CAMD RF 38-11355-668

KV-9 Trials

"According to order #012 of the NKO and the order #48s of the People's Commissariat of Tank Production, the commission led by Major-General of the tank forces comrade Ponov tested the KV-9 tank armed with the 122 mm M-30 howitzer from February 2nd to February 11th, 1942.

1. Goal of trials.

A KV-9 tank produced by the Kirov factory on the chassis of the KV-1 tank (see attachment #1) was submitted for trials. The KV-9 is armed with a 122 mm U-11 (M-30) howitzer designed by the Ural heavy machine building factory. The 122 mm tank howitzer is based on the stock divisional M-30 howitzer (see attachment #2). The KV-9 turret differs from the KV-1 turret in the following ways:

1. Increased gun port
2. Altered position of optical devices

2. Trials of robustness and precision.

The factory proving grounds tested the robustness of the gun mount using 171 increased power testing shots. Before trials, the mount was disassembled and measured. The recoil was within the limits of 560-580 mm. During firing, samples of gas concentration in the driver's compartment and fighting compartment were gathered. 

Additionally, the tank made 39 shots at targets at ranges of 600 and 1000 meters with shifts of fire at the Kopeisk proving grounds. The results of the shots are shown in the following table."

The following table does not list where the shots hit, but their time, range, and target are recorded. The tank can reload and fire in as little as 12 seconds, although the time is noticeably larger occasionally (when a target is reacquired, for instance). At 1000 meters, the tank shoots at a 5x5 meter target, at 600 meters, at a 1.25x1.25 meter target. 

"Note: during robustness trials, there were cases where the shell did not extract, which is explained by the use of old steel shells that have been re-loaded and the chamber being dirty.

All targets were hit directly. During gunnery trials, the tank drove 40 km over paved roads and 25 km off-road. The results of the trials are as follows:

1. The gun and mount system successfully passed robustness trials of 171 increased power shots. Measurements taken before and after trials have no difference between them, and are available in attachment 3.
2. The recoil mechanisms performed normally and passed trials (recoil remained within 560-580 mm). The pressure in the recoil brake was 27 atmospheres before trials, and 26.5 after.
3. The rate of fire is two rounds per minute.
4. The precision is good. Fire can be shifted quickly and without delay.
5. The elevation and turning mechanisms are comfortable to use.
6. The loader's position is cramped and makes his job difficult, but ensures the rate of fire of two shells per minute.
7. The ammunition rack is designed satisfactorily, aside from the following points:
1. The metallic cover should be replaced with a tarp.
2. Cut out the metal wall in the section covered by the tarp.
3. Increase the amount of shells in the turret bustle to 6 shells.
4. Bead form the metal to increase robustness.
8. The angle of depression is 2 degrees. It is desirable to increase it to 4 degrees.
9. The oscillating gun mantlet is not equal in thickness to the front of the turret, and some parts remain uncovered.
10. The frame cover is cast. It is necessary to use a stamped frame cover.
11. It is only possible to refill the brake fluid when the tank is tilted by 10 degrees or the recoil brake is removed.
12. The recoil brake pressure can only be checked when the gun is retracted by 300 mm. It is necessary to move the pressure valve.
13. There is no foot trigger.
14. Move the elevation indicator to the gunner's control panel.
15. Put a pear-shaped cushion on the periscope.
16. At high elevation, the elevation mechanism carrier can hit the gunner's guard plate. Make a slot in the plate.
17. Move back the sight 40-50 mm for more comfortable use.
18. Move the fault indicator, as it is covered by the machinegun.
19. The manual extractor is inconvenient; it slips off the shell rim.
20. Tighten the mount for the driver's mirror. There were two cases where is was shifted during fire.
21. The march stopper is reliable and allows to bring the gun into firing condition within 5-6 seconds.
22. The angles of deviation are not measured due to a lack of stock shots. The gun was fired using T-34 sights.
23. Move the DT machinegun up so that the disk magazine does not rub on the gun.
24. In order to find out the concentrations of gas in the tank, probes were taken after 30-40 shots with the engine off and hatches closed. The results are:
1. Fighting compartment: 0.201 mg/L
2. Driver's compartment: 0.308 mg/L
   With the engine on, the concentration is acceptable.

Penetration trials

On February 10th, factory #200 performed penetration trials using the U-11 122 mm tank howitzer and A-19 armour piercing shells. 

Trials conditions:

1. Shell mass: 24.6 kg (not entirely identical to stock)
2. The shells were fired at a stock cast KV turret (110-115 mm).
3. The distance between the muzzle and armour was 100 meters. The first load was 2100 grams of 9/7 powder and 0.030 of igniter. Muzzle velocity: 525.4 m/s. The shell penetrated the turret wall completely and remained behind the armour (see photo #1).
4. Second shot. Propellant charge: 2200 grams of of 9/7 powder and 0.030 of igniter. Muzzle velocity: 540.2 m/s. The shell punched out a plug and ricocheted (photo #2).
5. Third shot. Propellant charge: 2300 grams of 9/7 powder and 0.030 of igniter. Muzzle velocity: 546.4 m/s. Same results as the second shot (photo #3).
6. Fourth shot. Propellant charge: 2400 grams of 9/7 powder and 0.030 of igniter. Muzzle velocity: 573 m/s. Same result as the first shot.

Due to a lack of measuring equipment, the pressure in the barrel was not measured. It is necessary to discover the optimal amount of propellant at the Nizhniy Tagil proving grounds.

Conclusions:

1. The KV-9 tank passed trials and can be adopted into service with the Red Army.
2. When producing the KV-9, all aforementioned drawbacks must be corrected, with special care taken regarding the armour and ammunition rack.
3. As the 122 mm M-30 tank howitzer version passed trials, the commission deems it necessary to accelerate the mass production of the KV-9 tank.

February 16th, 1942"

CAMD RF 38-11355-668

KV-9 Production

"To the deputy People's Commissar of Tank Production of the USSR, Major-General of Technical Forces, comrade Kotin
Chair of the Technical Council of the Council of People's Commissars, comrade Satel
Director of the Kirov factory, comrade Mahonin
Director of Kalinin factory #8, comrade Fratkin
Regional GAU KA engineer at factory #8, Engineer-Colonel comrade Kasheyev
Regional GABTU BTU engineer at the Kirov factory, Engineer-Lieutenant-Colonel comrade Kozyrev

On the issue of a trial production run of KV-9 tanks.

Trials of the KV-9 tank armed with a 122 mm U-11 howitzer ended in March of this year.

In August of this year, continuing this work, factory #8 produced two U-11 howitzers with corrections according to proving grounds trials, and Kirov factory (#100) made corrections to the KV-9 tank according to the conclusions of the commission.

I ask for your orders to assemble a trial run of KV-9 tanks with U-11 howitzers for battlefield trials. For this, the following is necessary:

• Factory #8: produce a lightened pipe guard for all howitzers according to the blueprints provided to the Artkom and send them to the Kirov factory (Chelyabinsk).
• Factory #69: develop blueprints for scope markings for the TMFD and PT-4 sights for a gun with the ballistics of the U-11 122 mm howitzer, produce three of each, and immediately send them to the military representative at the Kirov factory (Chelyabinsk).
• Kirov factory: equip the fighting compartment in the old type of turret with a fighting compartment, ammunition rack, a commander's cupola of the KV-1S type (forward and to the right). In order to lighten the tank to 45 tons, mount the turret on a lighter KV-1S hull.

I ask you to inform me of your orders and estimated completion times.

Deputy GAU KA Chief and Artkom Chair, Major-General of Artillery, Hohlov

Deputy GABTU KA Chief, Major-General of Tank Forces, Korobkov

October 23rd, 1942"

CAMD RF 81-12038-32

SKB-2's Experiments

"Experimental Developments of the SKB-2 at the Kirov Factory:

1. Installation of the 122 mm artillery system (M-30) into the regular KV-1 turret with a new armour scheme. Approximately 50 shells fit in the tank. A prototype is built at Uralmash, and will be tested in early January 1942.
2. Installation of the 85 mm anti-aircraft artillery system into the regular KV-1 turret, with approximately 80 shells that fit in the tank. A prototype will be ready by January 10-15, 1942.
3. A raiding T-34 is being developed, with a top speed of 70 kph, with lightened hull and suspension, as well as larger gas tanks for increased range.
4. A tankette called "Rage of the People" is being developed, 2.5 tons in mass with 20-25 mm of armour, powered by two S-65 tractor engines, with a crew of 2 and machine gun armament.
5. A pipe-less radiator made from sheet steel was tested separately, and soon will be tested on a car. There is no reason why we cannot mass produce this radiator.
6. A heater for tanks that moves the air heated by the engine to the crew compartment. At a temperature of -25 degrees, the compartment is kept at 12-18 degrees. This invention is already in production, and will be installed on all vehicles starting in January 1942.
7. Replacement bearings for idler wheels, road wheels, and suspension components with sliding bearings and ball bearings of local production.

Also, work is being done on replacement of steel casings of final drive gears and other non-worn components with cast iron, replacement of highly hardened 33xSA and 38xSA steels with high-carbon steel, stamping tracks with two halves in order to free up the heavy presses, cast tracks, and idlers with welded on cheeks for the track tension mechanisms."

CAMD RF 38-11355-870

The first item is quite obviously the KV-9, a KV-1 with the 122 mm U-11 howitzer. The second item is the somewhat lesser-known KV-10. Shashmurin's ridiculous tankette (who needs a tankette in 1942?) and the much more interesting raiding T-34 (I wonder if they saved the armour thicknesses) do not appear anywhere else.