Small Arms

November 13, 2019, 3:16 pm

"August 8th, 1942

To the artillery quartermasters of the 124th and 125th Tank Battalions

I report to you the supply of 7.62 mm rifle cartridges and F-1 grenades carried in KV, T-34, T-60, and T-40 tanks for precise inventory.

Tank	Total MG ammunition	Ammunition by type			F-1 grenades
Tank	Total MG ammunition	Light bullet	AP-I bullet	Tracer	F-1 grenades
KV	3000	2400	500	100	25
T-34	3000	2400	510	90	25
T-60	950	760	160	30	10
T-40	2000	1000	340	60	10

At the same time, I instruct you that AP-I ammunition should be loaded in magazines separately, not mixed with ammunition that has light bullets. Magazines with AP-I ammunition must be specially marked. Check how magazines were loaded in your units and load AP-I ammunition separately.

Report on execution of this order to the artillery supply department of the brigade by 16:00 on August 9th, 1942

Artillery quartermaster of the 112th Tank Brigade, Intendant 3rd Class, Tomilin"

Via Ivagkin.

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Pistol Power

November 14, 2019, 7:51 pm

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Conservative elements within the tank corps favoured the Nagant M1895 revolver. It was relatively simple and could be fired out of a smaller pistol port than the TT. However, the Nagant took much longer to reload and could not use submachinegun ammunition in a pinch.

"For ISU-122 crews it is desirable to have a TT pistol, since the long loading time for Nagant revolvers puts the crew into a critical position. The limited amount of ammunition in a revolver causes frequent reloads. There is also much more ammunition for a pistol available inside the vehicle."

Via Andrei Ulanov.

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A Barrel Too Long

November 16, 2019, 8:48 am

≫ Next: Experimental Work at Factory #183 March 1941

≪ Previous: Pistol Power

Rapid growth in power of tank and SPG guns continued throughout WWII. Designers of some nations achieved the increase in firepower through a harmonious increase of gun caliber and barrel length. Other schools of design preferred to keep the caliber, but significantly lengthen the gun. The second approach was very common for German armoured vehicles. This decision had both positives and negatives. It turned out to be not so simple to install long guns on medium tanks. The Panzer IV/70 is a good example of this. An attempt to create a more powerful variant of the Jagdpanzer IV gave the tank destroyer both new abilities and serious problems.

Fishing rod for a medium chassis

The Wehrmacht's Armament Directorate began to think that the 7.5 cm Pak 40 needs a replacement as early as mid-1942. This gun had outstanding characteristics and could penetrate any tank at a medium distance, including the KV-1 and Churchill. However, experience showed that growth of firepower is always followed by growth in armour. The Germans had excellent foresight: in 1944 IS-2 and Churchill VII tanks could only be penetrated by the 7.5 cm Pak 40 and its derivatives at point blank range.

The first experimental PzIV/70 (V). The photo was taken only after the experimental remote controlled machine gun mount was installed.

A potential replacement for the Pak 40 turned up as early as February of 1942. This was a 70-caliber gun designed by Rheinmetall-Borsig engineers. It was designed for installation in heavy tanks, but ended up on the medium VK 30.01 (DB) and VK 30.02 (M). The second of these tanks was accepted into service as the Panther. The same gun, indexed 7.5 cm KwK 42 L/70, was also seen as a potential replacement for the KwK 40 and StuK 40.

However, the attempt to install the 7.5 cm KwK 42 L/70 in a PzIV failed. The gun was too long and its installation required changes to the chassis. Only models of the gun were ever installed. An attempt to use this gun in medium SPGs failed even faster. Designs showed that installing the 7.5 cm Pak 42 L/70 into a StuG 40 or the early Jagdpanzer IV prototype would require major changes to the casemate. Work stopped in early 1942.

The gun travel clamp can be seen in the front. This distinguishes the vehicle from the Jagdpanzer IV.

The issue of using the more powerful gun for arming tank destroyers was raised once more on January 27th, 1944, at a meeting with Hitler. The first Jagdpanzer IV was delivered that month. This SPG was selected as the recipient of the 7.5 cm Pak 42 L/70.

The StuG 40 Ausf.G was a poor choice for two reasons, both design and production. The installation of a new gun would require a major redesign of the casemate and engine deck. Nobody was going to begin altering the vehicles that were in such high demand as is. The Alkett factory was also bombed twice, with heavy damage. The situation was so serious that Alkett had to quickly develop the StuG IV to be able to use chassis produced by Grusonwerk.

Demonstration for Hitler.

Work on modernizing the Jagdpanzer IV began in the spring of 1944. VOMAG took a Jagdpanzer IV with serial number 320162 produced in March of 1944 as a starting point. As the fighting compartment was roomy enough to take the larger weapon, it was not necessary to radically alter the SPG. However, since the 7.5 cm Pak 42 L/70 was not only longer, but also heavier than its predecessor, the gun mount, mantlet, and shield had to be reinforced. The long and heavy barrel had to be affixed using an A-shaped clamp so it did not loosen during off-road driving. The ammo racks also had to be changed, as the new gun had a much longer round. The ammunition capacity decreased from 79 to 57 rounds. In everything else, the Jagdpanzer IV with the longer gun did not differ from a regular tank destroyer.

Production vehicles kept the same machine gun mount as the Jagdpanzer IV.

Hitler was first shown photographs of the new vehicles on April 6th, 1944. He saw it himself on April 20th, during a demonstration arranged for his birthday. Hitler was happy with the vehicle and it was greenlit. The official designation for the vehicle, Panzer IV lang (V), was Hitler's idea, given on July 18th, 1944. In the fall of 1944 it changed to Panzer IV/70 (V). The letter V meant the VOMAG company.

Overloaded front

On May 4th, 1944, the Armament Directorate prepared a document that called for 2020 Jagdpanzer IV vehicles of all types built between April 1944 and April 1945. Meanwhile, the situation with the Panzer IV/70 (V) was going poorly. It is not known if Hitler knew about this, but the Armament Directorate found out that the front of the vehicle was seriously overloaded. This was without the planned increase of the front armour from 60 to 80 mm! As a result of all these changes, the new SPG weighed nearly 2 tons more than the old one.

One of the first production Panzer IV/70 (V)s.

The 6th Department of the Armament Directorate had an idea about the consequences of such overloading. On May 16th, 1944, less than two weeks after the decision to put the vehicle into mass production, the department proposed to alter the running gear. The changes were not great: the front bogeys would be moved 100 mm forward to help with the change in the center of mass. This proposal was rejected. There was nowhere left to move them to.

On August 10th, 1944, the 6th Department proposed that the front armour should be reduced to 60 mm. This proposal was approved, but that was it. All Panzer IV/70 (V) were produced with 80 mm of front armour. The only proposal of the 6th Department that was put into practice was the installation of the remote control machine gun on the roof. This was only done on the prototype. The vehicle went into production without it.

The vehicles were covered in Zimmerit until September of 1944. However, enemy magnetic mines never turned up.

The first 60 Panzer IV/70 (V) were due in August of 1944, with subsequent increase in production: 90 in September, 100 in October, 150 in November, 180 in December, and 200 in January of 1945. The vehicle was supposed to replace the Jagdpanzer IV, but initial production vehicles were very similar to their predecessor. The biggest change was the travel lock. No changes were made in August and September production types. Nevertheless, only 57 were delivered in September, and even fewer in October: only 41.

The Panzer IV/70 retained its muffler until November of 1944.

It would seem that the first complaints about wearing out of the front road wheels started coming in the fall of 1944. It was too late to introduce any radical changes, especially since they would negatively impact the production volume. Starting in October of 1944 the tank destroyers merely received steel front wheels. Zimmerit was no longer used starting in September-October. The Germans did not end up seeing any magnetic mines that it was supposed to protect from. In October the production of the Panzer IV/70 (V) reached the requirement and even surpassed it: VOMAG delivered 104 vehicles out of 100 planned.

Vehicle with serial number 320996 captured by the British. It has no Zimmerit, the front road wheels are fully metallic, the number of return rollers was reduced to 3.

Bigger changes were introduced by the end of 1944. They were partially connected to the metamorphosis of the base chassis, the PzIV Ausf.J. The number of road wheels was reduced to three in early November of 1944. The muffler was also removed around that time. This change was first introduced in the Jagdpanzer IV, but it was much more commonly seen on its replacement. In November the air intake vent disappeared from the brake access hatches, but some vehicles continued to receive left over old hatches. For instance, the vehicle with serial number 320999 on display at Patriot Park has this type of hatch. The design of the rear tow hooks and machine gun mount cover also changed.

The vehicles also received lightened track links starting with November, which helped reduce its mass. Gutters to prevent rain from seeping through hatches were added in December, as well as a new top cover for the gun sight, which was now made from separate plates. Not all vehicles received it.

The Panzer IV/70 (V) received straight exhaust pipes instead of mufflers starting in October-November of 1944.

The rate of production of the Panzer IV/70 (V) remained high in late 1944. The plan was overfulfilled again in November: 178 vehicles were delivered instead of 150. 180 were produced in December. However, in January only 185 instead of 200 were built. This shortfall was caused by the growing agony of the German tank industry. The factory suffered from shortages of parts and electricity. In February 135 vehicles were delivered instead of 160. Somewhere around this time, some of the vehicles began to receive cast idler wheels. A simplified travel lock was used starting in early 1945. The periscopic sight received a visor to protect it from lens flares. The rangefinger mount was also changed.

These vehicles were produced in February-March 1945.

Production continued until March of 1945. Starting with March 19th, Plauen, the city where the VOMAG factory was located, was heavily bombed. On March 23rd the factory was destroyed completely. 50 out of the 180 planned vehicles were delivered that month. On that, production stopped. In total, VOMAG produced 930 Panzer IV/70 (V) with serial numbers in the 320651–321000 and 329001–329699 ranges.

An ersatz from Alkett

Despite the overloaded chassis and issues with front wheels, the Panzer IV/70 (V) was not a bad vehicle. At the very least, it was hard to produce anything better given the strict requirements that German designers were given. Nevertheless, the Panzer IV/70 (V) was not the only SPG on the PzIV chassis that received a Pak 42 L/70. The aim of increasing the volume of production led to the creation of another.

Prototype of the Panzer IV lang (A) mit 7,5 cm Pak 42 L/70.

The PzIV received its double due to the unsettling conclusions that the Germans made when studying a captured IS-2 tank. The new Soviet tank had thick armour that the 75 mm KwK 40 L/48 could penetrate only at point blank range. On June 24th, 1944, Alkett received an urgent order to install the 75 mm Pak 42 gun into the PzIV. The idea to install it in the turret was doomed to fail, as the chassis would be seriously overloaded. On July 5th, 1944, an idea was proposed to install the Panze IV/70 (V) casemate on top of the turret platform. The result was heavier than the Panzer IV/70 (V), but it could be made quickly and without changes to the base chassis.

Hitler inspects the band-aid solution.

On July 6th an experimental prototype of the Sturmgeschütz auf Pz.Kpfw.IV Fahrgestell was shown to Hitler, who approved the design. In any other conditions it would have been hard to find this proposal satisfactory. The casemate was 38 cm taller than the PzIV/70 (V). However, the overall height was only 2.2 meters, about the same as the StuG 40 Ausf.G. The mass, however, was much higher: 27 tons. On paper, the top speed was 37 kph. The power to weight ratio dropped to 10 hp/ton. It was hard to call the tank destroyer agile. Nevertheless, an alternative to the VOMAG design was born.

Unlike production vehicles, the Panzer IV/70 (A) prototype had its sides made from two parts.

In August of 1944 the SPG received the name Panzer IV lang (A) mit 7,5 cm Pak 42 L/70. However, the index introduced in November of 1944 is much better known: Panzer IV/70 (A). The letter A stood for the developer: Alkett. A different company ended up producing it, since Alkett was overloaded with orders for the StuG 40 Ausf.G.

It was easiest to build the vehicle on a PzIV chassis at a factory that already produced the PzIV. The order was given to Nibelungenwerk, the main producer of the PzIV. At a conference on July 6-8th, 1944, Hitler ordered a change to the production plan. 50 SPGs were planned in August, 100 in September. If Nibelungenwerk's capacity allowed, the factory would begin producing 150 vehicles per month starting in October 1944.

A production variant of the vehicle.

These plans never came to pass. Nibelungenwerk delivered its first Panzer IV/70 (A) in August, but only 3 instead of 50. Production vehicles were different from the prototype. The side of the casemate was built from one sloped plate. The protection of the machine gun also changes. It quickly turned out that the chassis needs the same changes as the Panzer IV/70 (V) chassis. Significant overloading, especially of the front, led to frequent breakdowns of the road wheels.

The first two bogeys on each side were equipped with all steel road wheels starting in September of 1944. On September 18th, new mesh skirts entered production. They were much lighter than the old ones, but offered the same protection from anti-tank rifles. Zimmerit was no longer applied starting in September of 1944. No photos of the initial production vehicles exist, but there were not so many of them built. Nibelungenwerk only built 60 vehicles in all of September.

Panzer IV/70 (A) with mesh skirts.

Production in Saint Valentin lagged behind the quota in the following months. 43 were delivered in October of 1944, 25 in November. The reduction is linked to damage dealt to the factory on October 26th by Allied bombers. In December of 1944 the plan for Nibelungenwerk was reduced to 80 Panzer IV/70 (A) per month, and the factory almost met it, delivering 75. In January of 1945 the order decreased to 50 tank destroyers. This was the only month when Nibelungenwerk met its quota.

The rear tow hook was changed in December, and this was the month when the number of return rollers was reduced to 3 per side.

This vehicle is showing its attachment to fire from a curved barrel StG.44.

20 Panzer IV/70 (A) were built in February. Production was no longer planned in March, but Nibelungenwerk assembled its last vehicles from its stocks. In total 277 Panzer IV/70 (A) with serial numbers 120301–120577 were built. The Panzer IV/70(A) was the last German wartime SPG to be put into mass production.

Some late model vehicles also had an unusual type of defensive armament: a StG.44 assault rifle with a curved barrel that the loader could fire through his hatch.

Further work performed by Krupp to improve the Panzer IV/70 (A). This project was never seriously considered, as the chassis was overloaded as is.

To finish, let us mention a variant of the Panzer IV/70 (A) that was never built in metal. In late 1944 Krupp proposed a number of projects to re-arm existing vehicles with more powerful weapons. The Panzer IV/70 would receive the 88 mm Pak 43 L/71. This gun could defeat any tank or SPG of the Allies, but the project was rejected. The gun would push the mass of the already overloaded SPG to over 30 tons.

Tank destroyers under questiong

The Panzer IV/70 (V) was used in the same way as the Jagdpanzer IV. Unlike the StuG 40, these vehicles were not used in assault gun brigades, but as reinforcements of tank, panzergrenadier, and SS divisions. The first vehicles were sent to tank brigades (105th to 110th). The TO&E specified that the tank battalion of this brigade had three companies of Panther tanks and a company (battery) of 11 Panzer IV/70 (V).

An early Panzer IV/70 (V) produced in August-September 1944, captured by the British.

The Panzer IV/70 (V) was used en masse in tank destroyer battalions. The 560th tank destroyer battalion was the first to receive 33 of them on October 6th, 1944. The Panzer IV/70 (V) was also used in the 655th (37 units), 519th (9), 559th (18), 563rd (31), and 510th (10) battalions.

In late March of 1945 one Panzer IV/70 (V) was sent to the 241st Assault Gun Brigade, and on February 10th 10 were sent to the 303rd Tank Battalion.

The Panzer IV/70 (V) was often used by SS units. Usually they received battalions composed of two batteries (10 vehicles each plus a commander's vehicle, 21 in total). Towards the end of the war this structure broke down. Any available vehicle could be sent to any unit to refill it or be sent to plug a hole.

A vehicle from the 12th SS division during the counteroffensive in the Ardennes, late 1944.

The difficult situation on the front lines had an impact on the use of the vehicles in battle. Loss of most of France cut the Germans off from their rear line training bases where units could prepare and organize. Now units were often sent to the front lines with little knowledge of their vehicles. The most new crews could hope for were brief courses on driving and shooting.

The finale of the battle for the Ardennes.

Even in these conditions and despite the overloaded chassis the Panzer IV/70 (V) could be a dangerous enemy for medium tanks. The 7.5 cm Pak 42 L/70 could penetrate enemy tanks from 1.5-2 km, while American 76 mm and Soviet 85 mm guns could penetrate its front only from 100-200 meters. Even the issues with quality of the Czech steel that these SPGs were built from did not help much.

In August of 1944 production of the IS-2 with a straight upper front plate began. This armour was too great for the gun of the Panzer IV/70, but the front of the turret could still be penetrated from about a kilometer away.

ISU-122, ISU-152, and SU-100 SPGs could also successfully combat the Panzer IV/70 (V).

Often only the very first road wheel was all metal, rather than the first two.

The Panzer IV/70 (V) was a dangerous opponent on the defense. The biggest problem was that an SPG had to move as well as shoot. Here is where the German tank destroyer fared poorly. German production plans made in February of 1945 continued production of 200 vehicles at VOMAG from April to May, then 150 from July. These vehicles would then be phased out for something more suitable, as the situation with their mobility and reliability was critical. However, Allied aircraft corrected these plans by destroying VOMAG.

Canadian trophies. One of them is currently on display at Base Borden.

Issues with the mobility and reliability of the Panzer IV/70 (V) were nothing compared to what was happening with the Panzer IV/70 (A). The first vehicles of this type were supposed to be sent to the front in September, but did not arrive there until mid-October. These tank destroyers were to be assigned as reinforcements to units that used PzIV tanks. At first, that was the case: 17 vehicles each were sent to the 3rd, 17th, and 25th tank divisions, 4 SPGs to the 13th tank division, and 13 in the 24th tank division. Towards the end of the production run the Panzer IV/70 (A) were sent to assault gun brigades in penny packets.

This vehicle was destroyed in combat around Berlin.

The opinion of the German command about this vehicle can be seen in the production plans made in February of 1945, where it is no longer present. Nibelungenwerk was freed from having to produce them. It was planned that production of the Panzer IV/70 (V) would be set up there.

The situation with the protection of the Panzer IV/70 (A) was interesting. Even by German data, it was significantly inferior to the Panzer IV/70 (V). For instance, the T-34-85 could destroy it from 1.5 kilometers. The front of the SPG was vulnerable to even British and American 75 mm guns. However, the Panzer IV/70 (A) often fell victim not to the enemy's guns, but to its own reliability. Even the Sturmpanzer assault gun weighed less than this band-aid solution.

A Panzer IV/70 (A) destroyed in battle with French forces. It is currently on display at the Saumur tank museum.

Some vehicles, captured by the Red Army, were issued to Bulgaria. One of them, with serial number 320662, is on display at the military museum in Sofia. Unlike the Jagdpanzer IV, the Panzer IV/70 (V) did not enjoy post-war service. The overloaded and unreliable vehicle was not needed. As a result, only five of the 930 tank destroyers produced survive to this day. Only one Panzer IV/70 (A) survives. This SPG with serial number 120539 was knocked out by French tanks in the winter of 1945, but retained its mobility. It was included in the French army, and later sent to Saumur, where it remains on display.

The SPG was put back into running order fairly quickly.

After the war the idea of creating a tank destroyer with a low silhouette remained. The Bundeswehr created the requirements for a similar vehicle in the late 50s, which gave birth to the Kanonenjagdpanzer tank destroyer. The Germans learned the lessons of WWII well, and the post-war tank destroyer had little to do with the Jagdpanzer IV, let alone the Panzer IV/70. The Bundeswehr sacrificed thick front armour and an excessively long gun in exchange for mobility. The Kanonenjagdpanzer remained in service in various nations until 1990. The mass of the Kanonenjagdpanzer was 27.5 tons, even heavier than the Panzer IV/70 (A).

Original article by Yuri Pasholok.

Walkaround of the Panzer IV/70 (A) in the Saumur Tank Museum.

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Experimental Work at Factory #183 March 1941

November 18, 2019, 2:30 pm

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"To the Chief of the 3rd Department of the BTU, Military Engineer 1st Class comrade Afonin

Summary report of experimental work performed at factory #183 in March 1941

Trials of cooling fans: three types of cooling fans entered trials.

1st variant: instead of blade supports special ribs were used. A vehicle with this fan travelled for 800 km. Trials will continue in April.
2nd variant differs from the production type only in the riveted rim that is the same as the BT-7M type. A vehicle with this fan travelled for 400 km. rials will continue in April.
3rd variant: production fan attached to the flywheel with a friction clutch to slip in cases of rapid changes of RPM in the driveshaft. A vehicle with this fan travelled for 80 km. Trials will continue in April.

Trials of the constant mesh gearbox were completed. This gearbox shows no advantages over the production type, and the top speed in 4th gear dropped by 5 kph, which is not desirable. There were also a number of defects found in several parts. It is pointless to implement this design into production.
New types of cast driver's hatches with different types of thermal treatment were tested by fire. One type showed good results in terms of ballistic resistance. The decision to put it into production is being made by the BTU.
Trials of a new type of turret ring with a different bearing runner to tighten tolerances. Trials showed that tolerances are tighter, but the turret can jam. Work on other variants is being performed.
8 types of air cleaners were produced. One of the types showed the best results (95% clearance) and was sent to Leningrad for government trials.
Reinforced Hadfield steel tracks were produced and tested. The assembled tracks made it to 2500 km after which the pin eyes were severely worn and the tracks began to break, the same thing as with production tracks.
Major modernization of the T-34: the model is complete. The design bureau is producing blueprints for the experimental design.

Military Representative of the GABTU, Military Engineer 3rd Class, Alekseev"

CAMD RF 38-11355-41 pp.306-307

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Detailed Trials

November 19, 2019, 5:51 pm

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"Approved by the Commander of Artillery of the 38th Army, Major-General of Artillery Likhachev

June 31st, 1944

Plan of firing trials demonstrating penetration ability against enemy T-4 and Panther tanks held by the 9th Guards Independent Kiev Order of Lenin Order of the Red Banner Tank Destroyer Artillery Brigade of the Supreme Command Reserve, as an element of the 38th Army

Held on June 4th, 5th, and 6th, 1944

Objective of the firing trials demonstration:

To illustrate to the NCO and private ranks the effectiveness of various types of shells fired from domestic weapons against enemy tanks.
To establish the penetration of weapons and the best distance from which to fire.
To inspire confidence in the power of our artillery against tanks.
To demonstrate the weak points of enemy tanks.
The demonstrate the effectiveness of dense fire of the small arms of an anti-tank battery against enemy submachinegunners that are advancing on the observation post.

Conditions of firing

Firing is done from guns of all calibers that are used within the army to fire on tanks using: subcaliber, AP, AP-T, HE, HEAT rounds.
The ranges of firing are 800, 500, and 400 meters. Fire is aimed at the front and side of the tanks with the same guns.
Firing from small arms is performed against targets placed 100-150 meters from the observation post, outlined by platoons from the 328th and 330th Guards Order of the Red Banner Tank Destroyer Artillery Regiments.

Weapons firing at the tanks:

122 mm model 1938 howitzer: 2 from 829th Artillery Regiment, 121st Rifle Division
76 mm model 1943 regimental gun: 1 from 878th Rifle Regiment, 121st Rifle Division
76 mm ZIS-3 divisional gun: 2 from the 328th Regiment, 9th Brigade
57 mm ZIS-2: 1 from 330th Regiment, 9th Brigade
45 mm gun model 1942: 1 from the 557th Independent Tank Destroyer Artillery Battalion, 121st Rifle Division
76 mm model 1927 regimental gun: 1 from the 121st Rifle Division
An anti-tank rifle squad and a grenadier squad from the 121st Rifle Division

Ammunition used:

122 mm: two rounds of each type to fire at the front and side from 400 meters
76 mm regimental: two rounds of each type to fire at the side from 400 meters
76 mm divisional: two rounds of each type to fire at the front and side from 800 meters with AP, HEAT, and HE shells and 500 meters with APCR
57 mm: two rounds of each type to fire at the front and side from 800 meters with all types except APCR. APCR is fired from 500 meters.
45 mm: two rounds of each type to fire at the side from 400 meters.

Only artillery of the 121st Rifle Division fires from 400 meters.

To supply the infantry attack demonstration the following is issued:

15 rifle rounds per rifle for training and 20 for the exercise.
One PPSh disk for training and two disks for the exercise.
Two LMG disks for training and two for the exercise.
One HMG belt for training and two for the exercise.

Organization:

First the weapons fire from 500 and 800 meter lines. Then the 121 Rifle Division artillery fires from 400 meters. The infantry attack is demonstrated last.
The 328th and 330th Guards Order of the Red Banner Tank Destroyer Artillery Regiments prepare a platoon each to demonstrate how to repel an attack of submachinegunners with small arms.
The exercise is directed by: from the south side, commander of the 328th Regiment Guards Lieutenant-Colonel Tereshenko, from the north-west side commander of the 330th Regiment Guards Lieutenant-Colonel Kremin.
To show the hit on the tanks, one officer each from the 238th and 330th Regiments should be in the vicinity of the tanks.
Major Kaflapov is responsible for the artillery of the 121st Rifle Division.

As a result of the trials, ascertain:

Effectiveness of different calibers and types of shells.
The best range from which to fire at tanks and their weak points.
Penetration of the 45, 57, 76 mm regimental, 76 mm divisional guns, and 122 mm howitzers.

Commander of the Brigade, Guards Lieutenant Colonel Kovanov

Chief of Staff, Guards Major Panisyuk"

Via Ivagkin

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Industrial Accident

November 20, 2019, 1:43 pm

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"Unscheduled report of an extraordinary event

Unit: GBTU Scientific Research Proving Grounds

Region: MVO

Event: wound during trials

Time: 10:00 August 8th, 1944

Location: shooting range of the NIBT Proving Grounds, Kubinka station, Western Railroad

Victims:

Rank and position	Name	Year of birth	Nationality	Education	Social status	Party affiliation	Place of birth	Nature of wound
Sergeant Loader	Toldykin, Fedor Pavlovich	1924	Russian	7 grades	Kolkhoz farmer	VLKSM	Sorochkinsk, Chkalov oblast	Ragged forehead wound
Sr. Sergeant Gunner	Butorov, Ilya Innokentivich	1922	Russian	5 grades	Worker	VLKSM	Bysherovo, Buryat Autonomous Soviet Socialist Republic	Minor head bruise

Description of the event:

On August 8th, 1944, at 10:00 when testing the effect of the D-25 122 mm gun (#266-44) installed on an experimental ISU-122 #249 against armoured hulls, the gun fired unexpectedly when loaded during the fourth shot, as a result of which the recoil of the gun wounded the loader Sergeant Toldykin (ragged forehead wound) and gunner Senior Sergeant Butorov, who received a minor bruise on the forehead."

CAMD RF 81-12038-312 p.373

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Staples

November 21, 2019, 2:05 pm

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Checking for tiny inaccuracies to detect forged documents is a pretty common phenomenon. Soviet counterintelligence had it down to an art. Forged documents confiscated from captured spies were analyzed for more signs to be used in the future.

"Party membership booklet: bright red cover with barely noticeable stripes. Rough and blurry font. The staples are made from stainless steel. The photo is printed on glossy paper."

"Inventory book: bright blue cover with a satin sheen. On page 3 item 1 the letters мен are missing in the word наименование. In the word книжка on page 3 the letter ж is capitalized and the first и in the word описания has a rightward stroke that continues downwards as a comma. On page 7 the letter и in the word описание looks like a п. On page 8 in the word свитер the letter в is replaced with a German "V". On page 15 the word описания has a dot above the и and я."

Via hranitel-slov.

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Long Awaited Tank Destroyer

November 23, 2019, 9:45 am

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History often moves in a spiral. The story of Soviet medium SPGs illustrates this fact well. In the summer of 1940, when development of SPGs on the T-34 chassis began, a tank destroyer was one of them. In the spring of 1942, the concept of the SPG changed, and the SU-122 was born. However, in May of 1943 a mobile means of defeating enemy tanks in the medium weight category was needed. On August 8th, 1943, more than three years after the request for a medium tank destroyer came through, the SU-85 was finally accepted into service with the Red Army. How well did Soviet industry deal with the vehicle that came to replace the SU-122, and how did it perform the tasks given to it on the battlefield?

Gradual transition

GKO decree #3892ss "On organization of production of the 85 mm SPG on the T-34 tank chassis at the Uralmash factory" issued on August 8th, 1943, did not give UZTM much time. Production of the SU-85 had to start on August 25th, and 100 had to be delivered by the end of the month. The plan for September increased to 150 units. UZTM still had to deliver 25 SU-122s in August, in addition to T-34s.

Factory #9 was instructed to supply 110 D-5-S-85 guns in August to enable this. The first guns had to arrive at UZTM by August 23rd. 170 guns were awaited in September.

The volumes and deadlines stated here seem very harsh. UZTM never produced more than 100 SU-122s per month. In addition, the factory often worked in emergency conditions. The problem was with irrational arrangement of production at UZTM and ChKZ. Stalin's demand to radically increase T-34 production led to entirely unaffiliated factories having to pick up the shortfall.

ChKZ was forced to reduce heavy tank production in favour of the T-34. It was even tougher than the SU-152 was added to the mix in the spring of 1943. Production of three vehicles at the same time (T-34, KV-1S, SU-152) proved challenging for the factory. Recall that in 1943 ChKZ produced 4 types of heavy tanks (KV-1S, KV-85, IS-85, IS-122) and two types of SPGs (SU-152, ISU-152). No tank factory in the world had to deal with such a horror.

Assembly of the first SU-85s, August-September 1943. The vehicle bears many slogans, including "To defeat the Tigers!"

The UZTM was also not doing well. The factory had much less power than ChKZ, and launch of the SU-122 into production was a serious trial. Not a single month in 1943 ended without an emergency. The factory either did not give enough SU-122, or not enough T-34s, or the quota was not filled for either. Something had to change, and GKO decree #3892 freed the UZTM from having to produce the T-34. Production at this factory never crossed 100 tanks per month, and threatening the very necessary SU-85 to produce such a small amount of tanks was senseless. It is also possible that this decision was made in connection with the return of V.A. Malyshev to the post of People's Commissariat of Tank Production. Stalin removed him from this position in the summer of 1942 specifically because of insufficient T-34 production.

UZTM delivered its last 9 T-34s in August.

A completed initial production SU-85.

The harsh deadlines had an effect on the choice to replace the SU-122. All three vehicles tested by the military were found unsatisfactory. To make work faster, the SU-85-I, SU-85-II, and SU-85-IV were built on the SU-122 chassis, mandated by GKO decree #3289 issued on May 5th, 1943.

However, UZTM was aware of the cramped fighting compartment of the SU-122. Gorlitskiy proposed that the UZTM should be given the task of developing a SU-85 with a widened fighting compartment by September 1st, 1943. This proposal was accepted, and the Department of the Chief Designer (OGK) of the UZTM developed this variant by the end of September. However, work did not proceed past drafts. The SU-85 that entered production was not much different than the SU-85-II.

Changes affected the gun mount, which was hurriedly improved at the factory #9 design bureau, as well as the gun shield and mantlet. The fuel system and electric equipment were improved, the panoramic sight hatch was enlarged by 100 mm to the right and 150 mm back. The commander's cupola received additional armour and the sight in it moved forward by 30 mm and 100 mm to the right. The gun port in the front armour changed to be like the one on the SU-122M, the pistol port on the right side was moved. The crew of the SU-85 also consisted of only 4 men.

The word "batch" is rarely used to refer to SU-85 production. The first batch was composed of pilot vehicles, late ones were not split into batches. Gorlitskiy proposed that a modernized vehicle would enter production later, but this never happened.

The SU-85 looked like this starting with the second half of September of 1943. The "brows" of the pistol ports are gone, the lifting eyes of the gun mantlet are different.

Like the GKO decree instructed, assembly of the SU-85 began in late August of 1943. By the 26th two vehicles were completed and entered trials. 200 shots with each gun were planned, but in practice gun #105 fired 251 times and gun #11 fired 300 times. The SPGs passed trials, but there were complaints about the gun shield that fouled the "pocket" of the mantlet. This increased the effort it took to move it. The commission composed a list of changes that would have to be made to September vehicles.

One vehicle passed 300 km mobility trials. The other was disqualified at 235 km when a water pump broke. Both SU-85s showed issues with road wheel rims. The SU-122 and T-34 exhibited the same issues.

A train with the first SU-85s, fall 1943.

The decision to put the SU-85 into production without serious changes saved a lot of time. The decision to stop parallel production of the T-34 also helped. The factory met its quota: 100 SU-85s were delivered by September 1st. The cost of one SPG was the same as one SU-122: 166,500 rubles.

The rate of production was affected by slow ramp-up of D-5S-85 gun production at factory #9. 10 SU-85s passed mobility trials in the first 10 days of September, of which only 26 had guns. However, by September 20th the factory delivered 83 SPGs and 152 in all of September, 2 more than required by quota. Even though the situation with guns repeated itself in October, the factory delivered 162 SPGs, again surpassing the quota by 2. In November the guns came gradually, instead of in bursts, and 166 vehicles were delivered instead of 165. In December the quota was also overfulfilled: 176 instead of 175. UZTM went from lagging behind to outstanding performance.

The situation with quality also improved. SU-85 #U309274 built in September of 1943 completed 1000 km trials with an average speed of 29.1 kph on a highway and 17.9 kph off-road. Inspection after trials showed that the engine and transmission are ready for further use. The weakest link was the road wheels. One broke due to the external ball bearing, another due to the rim peeling. Similar road wheel defects were encountered at other factories. Overall, the SU-85 was the most reliable Soviet SPG built at this time.

An improved gun mount approved for production in September 1943.

This didn't mean that the SU-85 had no issues. Both results of QA trials and reports of military representatives reflect this. Of 100 SU-85s assembled in August, Engineer Lieutenant Colonel G.Z. Zucher found only 54 defect free. The same situation occurred in September. Assembly was to blame for some defects but a number of them were due to the design. One of them was the attachment of a massive gun shield with only four bolts. This was not enough, and the shield began to sag after intensive shooting.

The factory tried to combat this defect by replacing one of the two shock absorbers with a metal liner, but it was clear that a new part needed to be designed. A new shield that was held by 6 bolts was approved on September 16th, 1943. This part was installed on production SPGs starting with the 95th produced in October.

The trigger mechanism changed even earlier, in September. This was also a problem part. On August 28th, 1943, a new commander's cupola was approved with sides strengthened to 45 mm. This got rid of the applique armour. The new cupola was introduced into production on September 20th, 1943. The location of the toolbox changed on September 1st, 1943. The left side ammunition rack also changed at this time. On October 1st a handle was added near the commander's cupola to make his work easier.

The lifting eyes of the gun mantlet also changed in September-October. Initially they were built as welded-on hooks, like on the SU-85-II. Later they were produced as loops, cast as one with the mantlet. The exhaust fan on the roof disappeared, it was replaced with a two-piece ventilation hatch. Interestingly enough, at least one production vehicle has this fan. When it appeared and how many vehicles were built with one is a mystery. The table of changes introduced into production does not have this novelty.

As of October 8th, 1943, the SU-85 was produced with a torsion bar compensator for the improved driver's hatch. These hatches were distinguished from the T-34's hatch with a C-shaped marking.

The SU-85 looked like this by the end of 1943. The gun shield is held by 6 bolts, new hand rails and additional track links on the front are installed.

The biggest change made in November of 1943 was the addition of spare track link holders on the front of the hull. The first vehicles to receive them were those produced on November 20th. On the same day, the panoramic sight hatch received torsion bars, which made it easier to open. The air engine starter was changed in November, and a drain for the gun mantlet "pocket" was added to get rid of water collecting there. The shape of the upper and lower front plate connecting beam changed some time in November. Instead of a round shape, it was closer to a triangle. This change was also not present in the list of changes introduced into production.

The design of the hand rails on the sides and rear of the casemate as well as the engine deck was radically simplified in December of 1943. The pistol ports were also simplified, the visors were now gone. There were no more noticeable visual changes in the SU-85, although development continued.

Adapting to production

UZTM overfulfilled the quota in January of 1944, delivering 176 SU-85s. In this month the subcontractor managed to fulfil their quota. By the morning of February 1st 165 guns were delivered. However, there were some complaints about them. For instance, the NIBT Proving Grounds returned one, complaining about a loose barrel. This resulted in high dispersion during shooting.

Factory #8 also received an order for D-5S-85 guns in late December of 1943, and two factories began producing guns for the SU-85 starting with January 1944. By February 1st, factory #8 built 36 guns and delivered 12. Factory #9 aided in organizing production. Factory #8 developed their own variant of the gun, indexed D-5S85A. The first such gun was assembled in late January.

This is what the SU-85 looked like by the spring of 1944. The SU-85A was not visually distinct.

Production of the "regular" D-5S-85 gun at factory #9 did not stop. The reason for this was pragmatic: factory #8 also built 52-K AA guns. The breech and barrel were used from them. The D-5S85A also used a different recoil guard than the D-5S85. Military representative Zucher was against this solution, as it introduced confusion in spare parts kits. Nevertheless, the D-5S85A passed trials in an SU-85 and was green lit for production.

An electric firing mechanism was tested in January of 1944. It was scheduled to go into production in February of 1944. Another novelty was the installation of two fans in the roof of the fighting compartment. This solution did not go into production. The price of a SU-85 increased to 185,000 rubles.

The last significant changes to the SU-85: shorter hand rails and shifted right hand pistol port.

The plan for production of the SU-85 was the same in February as January: 175 units. 54 were built by February 10th, 112 by February 20th. However, instead of the 200 guns the factory was supposed to receive, only 37 arrived. The factory only received the necessary guns by the end of the month, and the quota was overfulfilled again: 176 vehicles. Factory #9 delivered 139 guns that month and factory #8 delivered 42, some of the D-5S85A. The SPGs with this gun were indexed SU-85A. In March UZTM received 102 D-5S85 and 89 D-5S85A. 191 vehicles produced in March of 1944, 112 were SU-85 and 79 were SU-85A.

The situation with two guns that had the same purpose but non interchangeable barrels, breeches, and recoil guards was hard to call normal. An order was given to cease production of the D-5S85 at factory #9. This was done due to the fact that the T-34-85 was changing over from the D-5T to the S-53 designed by the Central Artillery Design Bureau (TsAKB). Of 200 SU-85s delivered in April, 175 were SU-85A. In May, all 205 vehicles were SU-85A. In June UZTM reached peak production, completing 210 SPGs. This rate of production was held all summer. The decision to free UZTM from T-34 production was wise.

The same vehicle from the top.

The design of the SU-85 continued to improve throughout the first quarter of 1944. The most noticeable changes were the shorter hand rails on the sides of the casemate that the SPG received no later than February of 1944. At the very least, the SU-85 with serial number 402221 on display in Warsaw already has these rails. Another noticeable change is the interlocking joint in the rear of the casemate. It was introduced in the 1st quarter of 1944. The pistol port in the right side changed its placement. New hinges for the panoramic sight hatch were added on February 20th, 1944. In March of 1944 the edges of the gun port were cut down and the pistol ports became bevelled.

The design of the gun mount bearing changed in January of 1944, and the turning mechanism carrier changed in February. In the 1st quarter the ability to adjust the gunner's seat vertically was introduced. Many complaints were made about the lack of this feature. The road wheel rims lost their ventilation openings towards the end of the summer of 1944. This was the last change to the design of the SU-85. Officially, the openings were cancelled by the end of April, but existing stocks meant that these rims still appeared. Factory #713, UZTM's road wheel supplier, only moved on to the new design in June of 1944.

The last change to the SU-85 was introduced around this time. After many complaints from the front lines the exhaust fan in the roof returned. Photos taken in the summer of 1944 show SU-85As with such a fan on the roof. This design was larger than the one on the SU-85-II, likely a large fan like on the IS-2 was used.

SU-85M belonging to Wojsko Polskie.

Work on modernization continued in parallel with production. The result of this work was the SU-100, the best Soviet SPG of this period. Stalin signed GKO decree #6131ss "On organization of production of SU-100 SPGs at the Uralmash factory and D-10S guns at factories #8 and #9" on July 3rd, 1944. According to this decree, production of the SU-100 had to start in September. However, it took time to ramp up production of the new vehicle and its gun, and so the SU-85A remained in production until November of 1944.

A hybrid entered production on September 1st, 1944. It was named SU-85M and essentially was a SU-100 with a D-5S85A gun. The installation of this gun into the new chassis had some problems, but it allowed the quota of 135 SPGs to be met. According to plan, 120 vehicles were delivered in October, and the last 60 SU-85M were built in November of 1944. After this, the factory fully switched to the SU-100.

In total, from August of 1943 to November of 1944 the UZTM factory produced 2650 SU-85, including 315 SU-85M.

Mixed success

The first SU-85 were issued in September of 1943. As it often happens with new vehicles, units began to complain about various defects. They were mostly linked to the D-5S-85 gun, but there were many others. The torsion bar of the driver's hatch broke often and had to be redesigned many times. There were also complaints about cracks in the armour, but not anywhere as many as the SU-122 caused. There were also engine and transmission defects. Complaints about insufficient ventilation resulted in experiments with two ventilation fans, but those were only approved on the SU-85M and SU-100.

Early SU-85 loaded on a train car, Sverdlovsk, fall 1943.

Officially, the SU-85 was designed to perform a wide spectrum of tasks, but it usually fought against enemy tanks. The first SU-85 SPG regiments were formed according to TO&E #010/483. According to it, the regiment was composed of 4 batteries of 4 SU-85s each. The regiment was also issued one T-34 tank as a commander's vehicle.

For instance, the 1435th SPG Regiment was formed in this way, the same one that started its career with SG-122 SPGs. This was one of the first regiments to receive the SU-85. By October 2nd, 1943, it was attached to the 68th Army. By 14:00 on October 2nd, the 1st battery of the 1435th regiment was in a defensive position at Klementyevo, subordinate to the commander of the 153rd Rifle Division. On the next day the Soviet forces began to cross the river Mereya at 11:30. Two SU-85s were supporting the offensive. The Germans opened fire at them. 1 was knocked out, and two of its crew were killed, two wounded. The other SU-85s in ambush opened fire at the enemy tanks and artillery that revealed themselves. The tank destroyers claimed a Tiger tank, but this was likely a different type of tank.

SU-85 on the front lines, late 1943.

A special commission was sent to the front lines to study the experience of using these vehicles. They included a representative of the Self Propelled Artillery Directorate of the GBTU, Engineer-Major P.N. Kuzin, an engineer from UZTM, B.B. Popkov, and the chief of tank production at the factory, L.M. Yarovinskiy. The objects of their study were the 69th Tank Regiment of the 8th Mechanized Corps and 1440th SPG Regiment of the 7th Mechanized Corps. The Tank Regiment was equipped with SU-85s according to TO&E #010/483, despite its name. When the commission arrived it had performed a 300 km march but not yet seen battle.

The 1440th regiment had already seen battle armed with the SU-122, having lost 6 SPGs irrecoverably and claimed 19 knocked out tanks, 15 burned up tanks, and 3 knocked out enemy SPGs. With their SU-85s, they had lost 5, claiming 18 enemy tanks, 6 of which were identified as Tigers. All surviving SU-85s had several hits to their front armour. Enemy shells formed dents up to 25 mm deep that were welded over. All losses were restricted to the initial period when the SPGs were used as tanks. After the SU-85 was used as instructed, the situation changed. As a rule, they would follow 200-300 meters behind the tanks. According to the crews, a Tiger's armour could be penetrated from the front at 600-800 meters and the side at 1200-1300 meters. The vehicle also turned out to be an effective infantry support measure.

Knocked out SU-85, early 1944. This was often the result when an attempt was made to use the SPG as a tank.

The SU-85 were rated highly by their crews. The precise gun, high maneuverability on par with the T-34, and high reliability were praised. However, by the fall of 1943 it was already remarked that the gun was not powerful enough. The gunners asked for a gun that could penetrate German tanks at 1500-2000 meters. This request was justified by trials against a Panther hull in late 1943, when it turned out that the shell could not penetrate the front. The crews also asked for thicker front armour. A proposal to revise the SPG regiment and increase the number of vehicles from 16 to 22 was made. The use of a T-34 as a commander's tank turned out to be a bad idea. The enemy figured out that this was a commander's tank and tried to knock it out first.

Soviet SPGs in Bucharest, late August 1944.

Despite the limited capability of the gun, the SU-85 was one of the Red Army's more effective SPGs. On November 22nd, 1943, in an ambush south of Yastrebnya, SU-85s commanded by Lt. V.S. Krysov and Jr.Lt. Makarov from the 1454th SPG regiment managed to repel an attack of 60 enemy tanks including 11 Tigers with help from an artillery battery. Krysov's crew knocked out 3 tanks and one more together with Makarov. A month later, on December 29th, 1943, Lieutenant V.A. Kurochkin excelled in the battle for Antopol-Boyarka. Kurochkin's opponents were two Tigers from the SS Leibstandart division. He managed to outmaneuver them and knock one out. Later Kurochkin will describe this battle in his story "War is War". The character of Maleshkin who was made famous in a movie of the same name is modelled after Kurochkin.

SU-85 with road wheels from a Panther.

There were many episodes like this in the SU-85's career. Yes, its gun could not always penetrate a Tiger or a Panther, but this did not prevent the tank destroyer from effectively fighting other tanks and SPGs. The Red Army finally received a medium tank destroyer that was closest to the German StuG 40 Ausf.G, but superior to it in nearly every way. The German assault gun had thicker armour, but it was presented at a flat angle.

Interestingly enough, during field repairs the SU-85 sometimes received road wheels from Panther tanks.

Considering the experience of the first battles, the commander's T-34 tanks were slowly replaced with SU-85 tank destroyers. Later, the TO&E #010/462 was introduced that increased the number of SPGs per battery to 5, and the total number per regiment to 21.

SU-85M in Berlin.

The SU-100 went into battle in early 1945 with a more powerful gun and thicker front armour, but the SU-85 remained the main Soviet SPG until the end of the war. These SPGs, including some SU-85M, ended up in the Wojsko Polskie. After the war, these SPGs remained in use alongside the SU-100. Most complete SU-85s that survived to this day can be seen in Poland. In addition to two surviving SU-85s, the museum in Poznan has the only surviving SU-85M. Today there are 11 SU-85s that survive in various conditions. The most interesting one can be seen in Tbilisi, as it is the only SU-85 produced in 1943 that survives to this day. The Central Museum of the Armed Forces in Moscow also has its own SU-85.

Original article by Yuri Pasholok.

Walkaround of the SU-85 from the Central Museum of the Armed Forces.

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Tanks Review

November 25, 2019, 2:05 pm

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"Exchange of experience in using tank weapons in the Patriotic War

The use of tanks in battle, especially in the winter offensive of 1943, showed several peculiarities of using tanks in battle, their advantages and disadvantages.

Typical distances for firing from a T-34 tank from standstill in defense or ambush is 1000 meters. When firing on the move or from short stops during offensive action the distance is the same.
The practical rate of fire of the 45 mm gun is 3-4 RPM. For the DT it is one disk (63 rounds) per minute. From the 76 mm gun it is 16-17 RPM. In a cohesive crew the radio operator can help hand ammunition into the turret without being distracted from his work.
Typically 3-4 rounds are used to suppress an enemy position when firing on the move or short stops. Cases where only 2 rounds are needed from a distance of 800 meters are not uncommon. There were cases where a heavy mortar position was destroyed from 800 meters with just one shot.
In battle by Kharkov in March of 1943, Captain Tolochniy destroyed 3 German tanks at a distance of 500-600 meters, spending no more than 3 rounds on each. In the same battle he destroyed an enemy SPG with two shots. In the last case he was firing from a standstill against stationary targets.
The most effective fire is from standstill or short stops at a range of up to 1000 meters. Firing from the move is less effective, but still necessary from a morale point of view.
Firing should be done from all of the tank's weapons. Typically the tank fires on the move at a speed of 15-20 kph. The effectiveness depends on the skill of the gunner (commander). The best trained commanders can deliver heavy damage to the enemy when firing on the move.
For instance, in the region of Perekopovka (Voronezh oblast) in August of 1942 Senior Lieutenant Kolodtsov destroyed an enemy gun with two rounds and a dugout with 3 rounds firing on the move from 800-900 meters.
During an attack the tank usually discovers the enemy positions by the flashes of enemy guns. These can be seen through optical sights. In the depth of enemy defenses as well as during pursuit observation is performed through the open hatch. Once the target has been located, the gunner tracks it through his sight. It is rare to be harmed while observing through an open hatch.
Concentration of fire on important targets is usually done through tracer fire, shell fire, flares, or the directions from the commander's tank. Sometimes the company or battalion is pointed at a specific target by radio.
For instance, in battle on January 19th, 1943, at Voldyrevka a company of T-34 tanks commanded by Senior Lieutenant Okunevskiy caught up with shooting up enemy cars and did not notice an artillery battery off to the side. Senior Lieutenant Okunevskiy concentrated the fire of his platoon through a stream of tracer bullets and shells. The battery was suppressed before it could open fire at the platoon.
Direction inside the tank is given by voice through the TPU. Within a squad it is given by tracers, shells, and flares in the direction of the target.
Fire correction at all distances is achieved by setting a fork and then transferring the aim point. The driver greatly assists the gunner in correction by observing the terrain.
Usage of the ammunition in the tank depends on the conditions. There were cases where all ammunition was expended in 20-25 minutes. There were cases where each tank used no more than 9 shells in 24 hours. Usually this happened while pursuing a quickly retreating enemy in the winter through deep snow.
The average expenditure of one ammunition load is two hours of battle. Crews refill at supply points. There were cases where crews received ammunition from another tank that was either knocked out or could not move for technical reasons.
The most common problems with the 45 mm gun is misfires, the most common problem with the ShVAK gun is jamming, the most common problem with the 76 mm gun is short strokes if very dirty or too heavily oiled. There were cases where the shell did not exit the barrel due to a defective charge and was knocked out with a blank. It is necessary to carry blanks for this purpose.
When firing from domestic tanks the commander observes the battlefield, searches for targets, fires, and corrects the fire. The driver assists with fire correction. The turret commander loads the cannon and machine gun. The radio operator operates the radio, fires the bow gun, and assists the turret commander with loading. If the commander is knocked out he is usually replaced with the turret commander, but there are cases where he is replaced with the radio operator. This depends on the level of training of the turret commander and operator.
The biggest drawbacks and deficiencies of newly arriving crews from reserve regiments and marching companies are:

Weak knowledge of the materiel, armament, and their tanks.
Weak training in firing and correcting fire, especially on the move.
Cross-training is not performed.
Turret commanders, not to mention radio operators, do not know optics and cannot use them.
There is not enough practical driving training.
To improve the effectiveness of the crews it is necessary to teach them to place all instruments and spare parts in their proper place, and not wherever they want, and get rid of all extra weight in the tank (personal belongings, other items not necessary for battle).

Conclusions:

T-34 and T-70 tanks showed themselves well in battle. In skilled hands they are dangerous weapons against fascist forces.
Newly arriving crews are not well trained enough and are not fully prepared for fighting.
Visibility from domestic tanks is insufficient. It is difficult for crews to observe the battlefield and find their way around.

Chief of Staff of the 36th Tank Brigade, Zubkov

Deputy Chief of Staff for Operational Work, Major Drozdov"

CAMD RF 3304-1-16 pp.169-171

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British Demo

November 26, 2019, 1:57 pm

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By the summer of 1941 the British were still struggling to equip their army with modern anti-tank weapons in the face of a German invasion, which was considered all but a certainty. This rush resulted in a number of weapons, from more conventional anti-tank cannons to rifle grenades and bombards. The comparison of the weapons' effectiveness is fairly predictable.

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Situational Awareness

November 27, 2019, 1:39 pm

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"Instructions for tank watchers

Tank watchers are selected from each battery to warn about the approach of tanks. They are placed in important directions no closer than 800-1000 meters to their positions.
The tank watchers are subordinate to the battery commander and battery duty officer.
The tank watcher is a sentry and must not leave his post until relieved or permission is obtained.
The tank watcher is responsible for warning the battery that tanks have appeared in his sector in a timely manner. He observes from a special observation post. His replacement should be housed in a dugout 10-15 meters away from the post.
If tanks appear, the watcher fires two flares in the direction that they are coming from.
At night, after firing the flares the watcher lights fires or other illumination that have been prepared in advance.
In the daytime, after warning the battery that tanks are approaching the watcher returns to the battery observation post immediately.
If the watcher does not give timely warning, he will be arrested and prosecuted by a military tribunal.

Chief of Staff of the 22nd Independent Anti-Tank Artillery Brigade, Lieutenant-Colonel Shubovich

December 9th, 1944"

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Up-Armoured T-34s

November 28, 2019, 1:57 pm

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"Changes and simplifications of the hull and turret

On November 25th, 1941, the factory moved to a simplified hull. The mechanical cutting of the rabbets was simplified. The stamping of the lower rear plate (part 34.29.007) was also simplified. The full album of bluprints and technical requirements were sent out in the first few days of February.

According to the decree of the Committee of Defense the factory should have began building tanks with applique armour on the hulls and turrets by January 15th, 1942. In practice the first hull with applique armour was produced on February 25th, and the first turret on February 21st. In total there were 80 hulls and 109 turrets built with applique armour.

On February 13th, 1942, the Deputy People's Commissar of Tank Production comrade Goreglyad cancelled the applique armour.

On the thicker turret armour project, 4 samples were given to the factory. By March 1st 8 turrets with 75 mm thick walls were cast. These turrets are put into production.

In early February the factory performed experiments in extracting the gun from the turret through the turret ring. The results were successful and the factory was able to get rid of the opening in the rear (item 34.30.011). The turret is now more robust and reliable.

Starting with mid-February the hulls have been produced with a splash guard in the front that protects the turret from jamming. The splash guard is placed to cover the gap between the turret ring and hull roof.

Military representative of the BTU at factory #112, Military Engineer 2nd Class Gusak"

CAMD RF 38-11355-862 p.78

↧

From Medium Assault Gun to Medium Tank Destroyer

November 30, 2019, 10:14 am

≫ Next: Heavy Tanks vs Heavy Guns

≪ Previous: Up-Armoured T-34s

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.

Anti-Tiger measure

Work on an SPG armed with the 85 mm 52-K AA gun stopped in the spring of 1942. Designers moved on to assault SPGs. However, work on 85 mm tank guns continued, but not a single one made it past the point of a sketch.

107 mm 9S-1 gun developed by combining the 107 mm M-60 gun barrel and the M-30 carriage. This gun was built and tested.

Sometime in early 1943 (no precise date is available) the factory #9 design bureau headed by F.F. Petrov began working on a continuation to a family of towed guns on the 122 mm M-30 and 152 mm ML-20 gun carriages, which they started working on back in the fall of 1942 as a part of factory #8's design bureau. The following barrels were to be installed on the M-30 carriage:

107 mm model 1910/30 (ZIK-30)
107 mm M-60 (9S-1)
122 mm A-19 corps gun (D-2)
152 mm M-10 howitzer (D-1)

The 9S-1 and D-2 reached the trials stage, and the D-1 was even accepted into service with the Red Army and remained in use throughout the world for decades. A system similar to the D-2, the M-5, was created at the factory #172 design bureau. Neither gun was adopted into production, but the results of working on the D-2 were put to good use. The idea of installing the gun on the M-30 carriage was good. Later, this design was used to create the famous D-25T gun.

As for the development of 107 mm guns, it hit a dead end. However, an SPG with this gun was still designed.

A draft of a SU-122 with a 107 mm gun.

No documents survive to this day, not even the name of this SPG is known. Some call it the U-34, but this index was never used. In practice, this was the same SU-122, whose design was finalized only in December of 1942. It is likely that this project is dated early 1943. Its development is linked to the attempt to combine many gun systems on one carriage. It is now known what gun was to be used: the ZIK-30 or 9S-1.

However, by this time the star of the 107 mm guns had set, and even the basic variant of the SU-122 was under question. The SPG was very cramped, and discussion of the SU-35M or SU-122M began. Instead of the M-30, this SPG used the D-11 howitzer, which was much harder to combine with a 107 mm barrel. It is not surprising that this grassroots project without a name disappeared quickly, leaving almost no trace.

Impressive results of the 85 mm 52-K AA gun used against a Tiger tank kicked off development of 85 mm tank and SPG guns.

The results of trials against a captured Tiger tank in late April of 1943 were like a bomb that fell on Soviet tank design. The 76 mm gun could not penetrate it in the side at even close range, and not a single one of 15 shots fired from the M-30 howitzer resulted in a fair penetration. However, the 85 mm 52-K AA gun proved itself very effective. It successfully penetrated the front of a Tiger from 1000 meters.

Work on installing this gun on the chassis of the SU-122 began immediately after obtaining the results of the trials. To be precise, work that was already ongoing was retroactively approved. The Red Army Main Artillery Directorate (GAU) developed technical requirements for an 85 mm self propelled gun/tank destroyer on April 12th. This development was directly linked with the appearance of the Tiger. The main enemy of this tank destroyer would be enemy heavy tanks with 90-120 mm of armour, which the 85 mm gun confidently penetrated at a range of 500-1000 meters. According to requirements, the gun would be installed in the chassis of a SU-35M (SU-122M) SPG, which would have to be lightened by 1-1.5 tons. The gun would carry 60 rounds of ammunition, either vertical or horizontal ammunition racks were permitted. Interestingly enough, captured German PzIII and PzIV tanks were suggested as an alternative chassis.

The first mention of work on the SU-85 dated April 14th, 1943.

The requirements were approved by the GAU Artillery Committee on April 14th. On the same day, they were sent to the Kaliningrad, where the Central Artillery Design Bureau (TsAKB) was located. The letter from the chair of the Artillery Committee, Lieutenant General V.I. Hohlov, instructed the head of the design bureau, V.G. Grabin, that the 85 mm gun was the highest priority. It would be created by combining a barrel with the ballistics of the 85 mm 52-K gun and the recoil elements of the ZIS-5 gun. This layout was no accident, as it was based on the earlier development of the ZIS-25 gun. The gun itself was rejected based on a number of drawbacks, but the overall idea was deemed correct.

The GAU composed requirements for an 85 mm tank gun that would be the successor to the ZIS-25 on March 6th, 1943. This was the starting point for the design of the new SPG. In addition to the TsAKB, the requirements for an 85 mm SPG were sent to Sverdlovsk to factory #9 director L.R. Gonor, and director of the Ural Heavy Machinebuilding Factory (UZTM) B.G. Murzukov. Factory #9's design bureau would develop the gun, the UZTM would develop the chassis.

The deadline was set at May 5th. By April 29th the TsAKB was already completing the preliminary project, but factory #9 had not even officially accepted the order. Nevertheless, a telephone call transcript indicates that work already began. By the time GKO decree #3289 "On improvement of artillery armament of tanks and SPGs" was signed on May 5th, 1943, Soviet designers already had a certain backlog of work.

Three competitors on one chassis

Decree #3289 was an odd one. It didn't mention the TsAKB at all, and only the People's Commissariat of Tank Production, factory #9, and the Uralmash factory were identified as responsible for 85 mm guns. The decree ordered the production and delivery of two SPGs called SU-85 by July 1st, 1943. The start of the trials was postponed to July 10th. Factory #9 and Uralmash were instructed to prepare for production before trials ended.

D-5S-85 gun.

Representative of the Artillery Committee Engineer-Major P.F. Solomonov arrived at factory #9 on May 3rd. The director of the factory declined to develop the gun on that day, as the factory was busy with the D-11 and D-12. Things changed only on May 5th after Stalin signed decree #3289. On that day a meeting was called at factory #9 where a direction was decided upon. The D-11 gun was taken as the starting point. Guns for SPGs had a higher priority: the 85 mm gun received the index D-5 and the 122 mm gun was called D-6. The tank variants of these guns were called D-7 and D-8 respectively. Interestingly enough, the design bureau of factory #8 was working on an 85 mm tank gun as well. This strange because when factory #9 split off from factory #8 the latter no longer had a responsibility to design tank guns.

Judging by Solomonov's report, the reality was different. Little data about factory #8's project survives, but it is known that it used the cradle from the F-34 gun, and the changes to the barrel would allow the armour piercing shell to achieve a velocity of 930-960 m/s. By May 8th work was well underway and working blueprints were even prepared. However, an order arrived from the NKV on May 10th to stop this work. The NKV reminded the factory that its job was to focus on towed guns.

Factory #9's improved design became the basis for a whole family of guns ranging from 85 to 152 mm in caliber.

Factory #9 gave new names to its guns: the D-5 became the D5-S-85, and the D-6 became the D5-S-122. The idea of using the ZIS-5 cradle vanished, and F.F. Petrov's bureau ignored some other requirements as well. The new gun was a further development of the U-11 gun, work on which began in the fall of 1941.

Recall that the U-11 was designed as a duplex. In addition to the barrel of the M-30 howitzer the U-12 with the ballistics of the 52-K 85 mm AA gun was later developed. The new gun was a reincarnation of this project, especially since the task of replacing the M-30 in the SU-122 still had to be done. In May of 1943 work on a very similar system with a 122 mm barrel began, the D-2. This work ended with the D-25, the most powerful Soviet tank gun mass produced during the Great Patriotic War. Also the D-15 gun with the barrel of the D-1 152 mm howitzer was designed in the fall of 1943. Unlike the D-25, it was never built. Nevertheless, its design alone demonstrates the versatility of the design.

Cutaway of the SU-85 with the D-5S-85 gun.

The D5-S-85 was a further development of the 122 mm D-11 gun. As with that gun, the development was directed by deputy chief designer A.N. Bulashev and deputy design bureau chief N.V. Kastryulin. During the development of the SPG duplex the designers took into account their past mistakes. The new gun was more compact and the mantlet was not as massive. A large casing in the front of the gun was done away with due to a redesign.

The elevation mechanism was borrowed from the F-34 for the sake of unification. All four guns had a common recoil brake, recuperator, and cradle. The D5-S-85 and D5-S-122 also had the same sight, frame, turning mechanism, and sight illumination. The D-5S-85 and D-5T-85 had the same recoil guard and brass catcher. Since the casing of the 52-K was longer, the guard had to be longer than that of the D-5S-122. Calculations showed that the recoil length of 350-370 mm was impossible, so it had to be increased to 430 mm

Initial design of the SU-85 SPG with an S-18 gun.

Design documentation for the D-5 family was ready by May 26th, 1943. At the same time, the competition from the TsAKB was working much faster. An SPG design with the S-18 gun was ready by May 16th, 1943. It turned out that 60 rounds would not fit, and only 50 would be carried. Unlike the factory #8 design, this gun was not a duplex. The project, headed by the head of the 3rd department of the TsAKB E.V. Sinilshikov, was developed only for installation into an SPG and only took an 85 mm barrel. Like with the D-5, the TsAKB did not use a pedestal mount, instead using a frame. The bore axis height increased from 1400 to 1600 mm, but the mass dropped from 30 to 29.5 tons. As required, the TsAKB maintained parts commonality with the ZIS-5 gun. Over 70% of the parts were reused. One of the biggest issues of the S-18 was the recoil length. At 470-570 mm it was nearly 1.5 times longer than required.

First place loser

The opposition of factory #9 and TsAKB followed a course that would later be repeated with tank guns. Grabin's group had time on their side, but the designers from Sverdlovsk had the advantage of a more developed system and physical closeness to the SPG factories.

Improved S-18 SPG project named SU-85-IV

The glacial pace of D-5 development led to the TsAKB taking an early lead by the end of May 1943 both in tank and SPG guns: first the S-31 gun for tanks, then the S-18 for SPGs. Factory #9 received blueprints of the S-31 by May 20th. Nearly all documentation for the S-18 was also delivered by then, aside from the traverse mechanism, sight adapter, and toolkit. Final documentation arrived on May 31st, in time for the deadline set by NKV and NKTP order #283ss/260ss given on May 8th, 1943.

SU-85-IV on the Gorohovets proving grounds, August 1943. The gun is at maximum elevation.

A number of issues were identified with the TsAKB's SPG during development. The commission remarked on a lack of communication between the TsAKB and UZTM, which resulted in some shortcomings of the design. According to conclusions made on June 8th, 1943, the SU-85 with the S-18 gun had decreased visibility from the driver's and commander's positions. Removal of the breech operator, which the TsAKB thought unnecessary in a vehicle with one piece amunition, was also criticised. Finally, moving the center of mass forward by 14 cm added stress to the front road wheels. The UZTM design bureau suggested that the TsAKB should change its gun by altering the ammunition racks and moving the gun back. At the same time, the oscillating part of the system would have to be narrowed. This variant was approved, but the TsAKB insisted on the initial design.

The commander's cupola can be seen from this angle. UZTM designers used a similar solution on all variants of the SU-85.

A trials program was approved on June 24th, 1942. The document listed three guns: S-18, D-5S-85, and the S-18 with changes requested by the UZTM. However, in June and even early July the chassis were not available. The S-18 was only tested in a jig on June 18th. Gun #5 made 23 shots, of which 1 had a reduced charge, 11 had a regular charge, and 11 were supercharged. Firing was done at various angles. The trials completed successfully, extraction happened without issues.

The same vehicle from the rear.

The initial TsAKB variant received the name SU-85-IV. It was still subject to some changes: the gun mount changed slightly, and a cap was introduced to protect the frame from water and dirt. The gun itself was also improved. The driver's working conditions became more comfortable. The changes in the fighting compartment were more radical. The TsAKB's idea to make a large ammo rack in the rear right corner was rejected, as it would have been uncomfortable to use. Ammunition was placed around the sides of the fighting compartment, under the gun, and in the left sponson. The ammunition capacity was reduced to 48 rounds, but it was now much easier to use it. The number of crewmen increased to 5, and the commander received a cupola in the roof. The cupola contained periscopic observation devices. The vehicle was accepted for trials in this configuration.

SU-85-I. This project appeared as a reserve variant.

The biggest issue with the S-31 at this time was a lack of potential for improvement. The GAU wanted to increase the muzzle velocity of the gun. On May 4th the Artillery Committee began a project on 85 mm guns with a barrel length increased by 12 calibers and muzzle velocity increased to 950 m/s. The S-31 was incapable of such results. This was the cost of parts commonality. The same was true for the S-18.

SU-18-I at the Gorohovets proving grounds.

The UZTM began working on converting the S-18 in early July of 1943. Experience of the D-5 family was considered when working on this gun, indexed S-18-1. As a result, it ended up having some parts in common with the D-5S-85, including elements of the frame and mantlet. The biggest change was the gun shield. The shape changed and a small hatch for access to the hydraulic system was added in the center. The height of the bore axis increased to 1635 mm.

The same vehicle at the UZTM courtyard. The access hatch in the front of the gun shield for servicing the recuperator can be seen.

The fighting compartment of the SU-85-I was identical to that of the SU-85-II. Nevertheless, the more rational design of the SU-18-1 had an effect. The mass dropped from 30 to 29.66 tons. Thanks to the more compact gun mount the overall length of the SPG shrank from 8320 to 8310 mm. The thickness of the gun mantlet grew from 30-45 to 52 mm, but its mass was reduced from 860 to 500 kg. The S-18-1 weighed 1160 kg without a shield. To compare, the S-18 weighed 1310 kg and the D-5S-85 weighed 1215 kg.

Gun at maximum depression.

The commission found no serious drawbacks with the D-5S-85. The smaller size and mass allowed the gun to better fit into the SU-85. The SU-85 with factory #9's gun received the name SU-85-II. It was very similar to the SU-85-I and SU-85-IV. The crew consisted of 5 men. The mass was 29.15 tons, the lightest of all.

SU-85-II in the UZTM courtyard, July 1943.

The deadlines set by GKO decree #3289 were not met. The development of the SU-85 went well into July. Experimental prototypes were completed by July 20th, and the vehicles arrived at the Gorohovets proving grounds on July 25th. Trials began that same day. First, the SPGs were inspected and loaded to full combat weight. Each one travelled 485 km from July 29th to August 1st, 373 km on a highway and 112 off-road. The SPGs drove from Sverdlovsk to Chelyabinsk and back.

The average speed on the highway was 22-24 kph, and 16-18 kph off-road. This was almost the same as a standard T-34. After long marches at a speed of over 25 kph the road wheels would take damage. This was a problem not only with the SU-85, but with the SU-85. The mobility of the SU-85 was about the same as of the T-34. The new driver's hatch was nearly identical to that of the T-34 and provided good visibility. The exception was the SU-85-IV, where the massive gun shield covered up vision to the right. A common drawback of all SU-85s and the SU-122-III was the shifting of the driver's seat to the right of the hatch center, which reduced visibility somewhat.

Gun at maximum elevation.

The guns were inspected after the trials. It turned out that the vertical looseness of all of them increased, especially of the S-18-1.

Firing trials were conducted on August 3-4th. The D-5S-85 almost immediately took the lead, chiefly due to superior crew comfort. Thanks to its smaller recoil length and loading height, the rate of fire was the highest. The S-18 and S-18-1 achieved a rate of fire of 6-7 RPM, the D-5S-85 could fire at 8 RPM. However, none of the guns passed trials. The D-5S-85 was in the lead, but it had issues with the trigger mechanism and 30% of extractions did not happen cleanly. The recoil brake began leaking after 10 shots. After 266 shots the brake lost about a liter of hydraulic fluid. The gun short-stroked on the 267th shot and the recoil brake broke. The gun had design flaws as well: the trigger mechanism was in an uncomfortable place and was hard to operate.

Of all experimental prototypes, the SU-85-II was the lightest.

However, the issues with the D-5S-85 were nothing compared to what the TsAKB gun produced. Problems began with the 5th shot and continued throughout the trials. Over 80 shots the semiautomatic mechanism failed 15 times. The breech would often close itself. The pressure in the recuperator reduced from 28 to 23 atmospheres after 40 shots. The fluid hydraulic also heated up quickly. There were many short strokes, and harsh returns with knocking began after the 70th shot. After 200 shots the mechanism broke completely. This gun had serious design defects, for instance the mantlet had to be removed to refill the hydraulic fluid.

The S-18-1 fared somewhat better, but many issues of the S-18-1 were also present. The recoil length gradually increased, after 173 shots the hydraulic fluid began to leak. Harsh with knocking began after 31 shots. Of the last 110 shots fired, 47 had the breech close itself.

Despite a number of defects, the product of cooperation between UZTM and factory #9 proved successful. The mass produced SU-85 had few differences.

After comparative trials work on the S-18 and S-18-1 ceased. The D-5S-85 was a clear winner. However, the final verdict was conditional on the resolution of defects with the gun. The chassis was also not fully satisfactory. A wider fighting compartment like on the SU-122M was proposed, but in practice the fighting compartment was not radically altered. The SU-85-II was accepted into service nearly unchanged. It happened on August 8th, 1943, when Stalin signed GKO decree #3892ss "On organization of 85 mm SPGs on the T-34 chassis at the Uralmash factory". The first production SPGs were built in August of 1943.

The SU-85 was the first mass produced Soviet SPG that was designed entirely in Sverdlovsk. UZTM staff received awards from the government for this project, the highest of which was the Stalin Prize. Factory #9 staff received high awards as well.

Original article by Yuri Pasholok.

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Heavy Tanks vs Heavy Guns

December 2, 2019, 3:39 pm

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Valeriy Lisyutin posted an interesting set of photos recently, one of which was a knocked out Tiger. These aren't particularly interesting on their own, but it had two things that are usually hard to find: a date and a place. I decided to investigate.

The caption reads "Tiger tank knocked out by the 1st Guards Gun Artillery Brigade, April 17th, 1944, near Hod. Velki". That mapped to Chodaczków Wielki, or Velykyi Khodachkiv in modern day Ukraine.

Thanks to Schneider's "Tigers in Combat", it was not too difficult to find out where this Tiger came from.

"16 April 1944: Relief attack continued with 12 operational Tigers in support. Several antitank positions were wiped out and Hill 363 was captured. Initial contact with the defenders of Tarnopol was established. The 1./schwere Panzer-Abteilung 507 in Brody reported 5 tanks operational.

17 April 1944: The 2./schwere Panzer-Abteilung 507 attacked north of Seredynki; it had eight operational tanks. The 1./schwere Panzer-Abteilung 507 in Brody reported eight operational tanks.

18 April 1944: The relief attack bogged down and a withdrawal was executed during the night. One company remained in support of the XXXXVIII. Panzer-Korps. Eight tanks reported operational; seven of them with the 1./schwere Panzer-Abteilung 507.

19 April 1944: Withdrawal to the area of Taurow"

Serednyky is right next to Velykyi Khodachkiv, so these are likely our tanks. The actual losses are not given in the diary, and the total numbers are muddled by the 1st company repairing their vehicles in Brody, but the 2nd company dwindles from 12 tanks on April 16th, 8 tanks on April 17th, and just one tank on April 18th. Let's see how this looked from the Soviet side.

On April 16th the 1st Guards Gun Artillery Brigade does report a tank attack.

"Until 16:00 no enemy tanks were seen on the battlefield. After 16:00 our offensive began following an artillery barrage. Having detected our offensive, the enemy moved out 17 Tiger tanks towards Buntsuv. Infantry was brought in with APCs and took up positions. Massed barrages of our artillery did not have an effect. Enemy tanks stood in place and did not permit our units to move up.

Brigade commander Guards Colonel I.M. Semak changed tactics of fighting and suppressing tanks. Guns would engage tanks individually. This kind of method increased the effectiveness of fire noticeably. After the target (an individual tank) was caught in a 100 m fork it would either leave or burn from a direct hit."

17 is a bit more than the Germans claim to have sent, but Schneider mentions aid from 9th SS division Hohenstaufen. In any case, more photos from the battle show that there were tanks other than Tigers assisting.

PzIII tank knocked out on April 16th, 1944 by the 1st Guards Gun Artillery Brigade near Hod. Velki"

The real slaughter of Tigers took place on the following day.

"April 17th, 1944. The enemy began an attack with tanks towards Kovalyuvka along the Pochapintse highway at 10:00, but had no success. Tanks were stopped by our artillery and partially burned. The enemy retreated with losses.

Our units turned to the attack and with support from tanks and artillery pushed the enemy back, moving to: south-west of Kovalyuvka, 1 km north-west of height 359.0, 1 km north-east of Seredynky. Changing their battle order, the brigade took up the following positions:

Command post 1: East of height 347.0
Command post 2: In the north-western clearing in the forest west of Petrykuv
Command post 3: In the western clearing in the forest south of Yanuvka
Observation post 1: On the nameless height 0.5 km east of Pochapintse
Observation post 2: On the nameless height 800 m of point 360
Observation post 3: height 360.0

The brigade fired to deflect tank attacks and at concentration of tanks near Kovaluvka, nameless height north of Seredynky, and at the observation post at the Hodachkuv Velki railway station. 559 rounds were expended.

Effectiveness of fire:

1st battalion burned up one Tiger tank, knocked out 3 Tiger tanks, destroyed 20 soldiers and officers.
2nd battalion knocked out two Tiger tanks, dispersed 15 tanks, destroyed 15 soldiers and officers.
3rd battalion burned two Tiger tanks, knocked out two tanks, deflected 4 tank attacks, and destroyed 60 soldiers and officers.

Losses: 3 privates killed, one contused.

Brigade HQ: homestead 1.5 km north-west of Yanuvka"

Claim of 8 Tigers and two other unnamed tanks (looks like more from Hohenstaufen) with the Germans reporting a loss of 7 that day, pretty close. It's no wonder the Germans took heavy losses: the 1st Guards Gun Artillery Brigade was armed with a whopping 31 ML-20 gun-howitzers, which would be lethal to a Tiger in direct or indirect fire.

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What's in a Name?

December 3, 2019, 1:42 pm

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"Order of the People's Commissar of Tank Production of the USSR #51ss

Moscow

October 6th, 1941

In carrying out the GKO decree #743ss issued on October 4th, 1941, I order that:

The following are renamed:

Stalin Chelyabinsk Tractor Factory to Kirov factory. Refer to it in full as the "People's Commissariat of Tank Production Kirov factory in Chelyabinsk".
The Sergo Ordzhonikidze Ural Heavy Machinebuilding Factory to the Izhora factory and refer to it in full as the "People's Commissariat of Tank Production Izhora factory in Sverdlovsk".

Form a conglomerate to produce KV tanks within the People's Commissariat of Tank Production including the following factories: Kirov (former ChTZ), Izhora (former Uralmash), and Ural Turbine Factory.
Appoint comrade I.M. Zaltsman, director of the Kirov factory, as the director of the heavy tank production conglomerate, preserving his current post.
Appoint the chief designer of the Kirov factory, comrade Zh.Ya. Kotin, as the chief designer of the heavy tank production conglomerate, preserving his current post.

People's Commissar of Tank Production, V. Malyshev"

Via Padikovo museum.

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Soviet Zimmerit

December 4, 2019, 2:07 pm

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"Instructions on combat against German magnetic HEAT mines

Over the last two months of fighting on the Belorussian Front there were many cases of our tanks blowing up when attacked by the enemy.

It was established that:

Tanks blow up only in the event of ammunition detonation.
The ammunition cooks off when the fighting compartment is struck by a magnetic anti-tank HEAT mine.

The magnetic anti-tank HEAT mine consists of an explosive charge weighing about 1 kg in a sheet metal casing arranged in the shape of a cone. A cylindrical detonator is attached to the top of the cone. A fuse akin to hand grenade fuses is attached to the top of the detonator. It has a longer time delay setting (4.5-7 seconds).

The lower part of the cone has three powerful permanent magnets attached with screws. These magnets attach reliably even to the belly of the tank. The mine resembles a watering can or a loudspeaker.

Magnetic HEAT mines are deployed by infantry by either throwing them at the tank or placing them manually on the side or belly of the tank when it crosses a trench.

Effect of the magnetic HEAT mines

The soldier pulls the cord and throws the mine at the tank. The latter sticks to the armour using its magnets and blows up after the delay. The tank travels 50-100 meters in this time. The powerful explosive wave focused by the cone can penetrate up to 140 mm of armour and get inside the tank. Anything in the path of the wave will be destroyed, flammable liquids will ignite, and ammunition will cook off.

Protection from the mine

When attacking enemy trenches they must be suppressed with machine guns and cannons.
The enemy's infantry cannot be allowed to approach the tank, destroy them with fire.
In winter, cover the tank with an 8-10 mm thick layer of clay. After it freezes paint the clay with white paint.

How to cover the tank to protect it from magnetic mines

The tank's armour must be cleaned (especially from oil) and washed. After that, a small metal spatula is used to apply a layer of clay. If possible, use clean clay without lumps or foreign materials. Mix the clay in water until it has dough-like consistency. Apply it to the armour and let it freeze. The layer should be 8-10 mm thick. If possible, they clay should not be applied evenly. Cover the turret, sloped sides, front plate, and belly.

This kind of protection will reliably protect against the magnetic HEAT mine. The mine will not be able to stick to the armour and will either fall off in motion or explode without contact with the armour. In this case, it does not do any damage to the tank

The crew must carefully track the state of their clay layer. If the layer is maintained, the crew can be confident that their tank will not be destroyed by a magnetic HEAT mine.

Senior Assistant to the Chief of the Armoured and Motorized Forces of the Baltic Front, Engineer-Major Tsyganov

December 28th, 1943"

Via ivagkin.

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December 5, 2019, 3:06 pm

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"State Committee of Defense Decree #6679s

October 10th, 1944

Moscow, Kremlin

On the installation of 520 hp V-11 engines into IS tanks and SPGs

The State Committee of Defense orders that:

The People's Commissariat of Tank Production is permitted to produce and install V-11 engines adjusted to the power of 520 hp at 2000 RPM into IS tanks and SPGs before trials of modernized tanks and SPGs with an improved cooling system are completed.

Chairman of the Committee of Defense, I. Stalin"

Via Padikovo Museum

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Kotin's Bobtail

December 7, 2019, 12:10 pm

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In early 1943 the Red Army Main Armoured Vehicle Directorate (GBTU) and People's Commissariat of Tank Production (NKTP) agreed that the age of the KV-1S is coming to an end. Instead, the IS-1 (233), a further development of the KV-13, was to be produced in Chelyabinsk. This tank had the same firepower, but was more mobile and better protected. However, the experimental IS-1 was too unrefined and suffered from assembly issues. In addition, trials of the German Tiger tank showed that the Red Army was in need of a tank with an 85 mm gun. This was how the KV-85 was created, the last mass produced tank in the KV family.

A fast alternative to the IS

At first, the idea of modernizing the KV-1S was not discussed. According to the GKO decree "On production of IS tanks and SPGs at the Kirov factory", production of the KV-1S ceased in June of 1943. The ChKZ would switch to the SU-152 exclusively, producing 200 of them in June and 100 in July. This factory would also build the SU-122 (an SPG with the A-19 122 mm gun). Production stopped in July, and ChKZ was expected to produce 50 IS-1 and 50 ISU-152/122.

This proposal was declined. Instead, degree #3289 "On improving armament of tanks and SPGs" was signed instead. According to this decree, two prototypes each of IS-1 and KV-1S tanks with 85 mm guns would enter state trials on July 1st, 1943. Work on the 85 mm tank gun began in March of 1943 and showed that significant changes to the tanks were required.

D-5T-85 gun in the IS-1 turret.

The design of an 85 mm gun with the ballistics of the 52-K AA gun was a competition. The Central Artillery Design Bureau (TsAKB) was working on such a gun in Kaliningrad (modern day Korolyov). Their project was aimed at changing as little as possible in the chassis to speed up production. The turret was altered to improve crew conditions.

Factory #9 workers in Sverdlovsk took a different approach. Their design had radically different changes to both tanks, including the IS-1. It was clear during the development of the D-7 (later D-5T-85) gun that it would not fit into the existing IS-1 turret due to the small turret ring diameter. The first draft of the D-5T-85 called for a 1700 mm turret ring, towards May of 1943 it was clear that the turret ring must be even bigger, 1800 mm wide. This meant that the IS-1 chassis would have to be radically changed, but the Chelyabinsk factory was ready for this. The IS-1 would be changed anyway, and there was no point in building two different turrets for one gun.

The same gun from above. The compact design and wider turret ring meant that the crew conditions were better than in the KV-1S.

The first steps towards this tank with the index 239 were taken in mid-May of 1943. Starting with July this tank was called Object 239. The draft was ready by May 22nd. The lead engineer on this project was M.F. Balzhi. In addition to widening the turret ring many other alterations were made. The radio operator was removed from the hull, and the radio migrated to the turret. The fuel tanks were moved to the front of the hull. Calculations showed that the mass of the tank would grow to 46.5 tons. Deputy People's Commissar of Tank Production and Chief Designer at ChKZ Zhosef Kotin was in favour of this development, but in no hurry to announce it. Nevertheless, the NKTP insisted on production of a prototype. The second production KV-1S with serial number 15002 was chosen for conversion. The due date was set at June 25th.

By mid-June blueprints of the "1st variant with installation of the IS turret" were sent into production. At the time the F-85 (aka S-31) gun was selected due to delays with D-5T-85 development. The attitude towards this project is described in the following paragraph from the report on experimental work.

"It is worth mentioning that both the Kirov factory and factory #100 prioritized the modernization of the KV-1S behind the work on of the IS-2. Attention will be given to the aforementioned work after the IS-3 components and assemblies are complete, which has the highest priority at the moment."

Object 239, Chelyabinsk, late July 1943.

In reality the factory did not manage to meet the deadline not only for the Object 239, but also for the Object 237, or IS-3. The senior military representative placed the blame for this on the Kirov factory, which distanced itself from this work. Not a single turret was built for any of the tanks. As for the chassis, the first Object 237 was finished by June 30th.

In parallel, factory #200 finished the conversion of the KV-1S 15002 hull. The alterations were not too great. The radio operator's space was removed, as the driver's compartment was redesigned. The MG ball mount port was welded over, and the MG itself was moved to a fixed mount to the right of the driver. Bulges were added to the sides, and deflectors were added to protect the turret ring. Finally, the roof above the driver changed. Since the turret was enlarged, he no longer had a hatch, and had to climb out of the turret. To compensate, he received two MK-IV observation devices, which improved his vision.

The welded over machine gun port is visible, as are the new observation devices above the driver's station.

By July 11th the factory had installed the running gear, fuel tanks, engine, and controls in the Object 239 hull. The turret was still not finished. In addition to the delays introduced by the Kirov factory, there was one single D-5T-85 gun built at the time. It was intended for installation into the Object 237 turret, which was completely assembled on July 8th. The newer tank still lacked a turret as of July 20th. The factory didn't wait for it to arrive, having completed the chassis and tested it over a 40 km run. Interestingly enough, the first D-5T-85 gun built still ended up in the Object 239 by the end of July.

All the changes increased the tank's mass to 46 tons.

The turrets of the Objects 237 and 239 were identical, which makes the mass difference all the more interesting. Object 237 weighed a little over 43.2 tons, Object 239 weighed almost 46 tons. However, it had its advantages. First of all, it had an impressive ammunition capacity: 70 rounds, compared to the Object 237's 59 and Object 238's (KV-1S with a stock turret and S-31 gun) 55. Secondly, as good as the IS-1 was, its production would take time, and the Red Army needed a tank that could fight Tigers now. The Battle of Kursk had just ended and only confirmed the low effectiveness of 76 mm guns against the newest German tanks.

The same tank from the rear.

Brief trials showed that the increase in mass had an effect on the tank's mobility. The average speed on a highway dropped to 16.4 kph, and off-road to 15.48 kph. The fuel expenditure increased to 409 L per 100 km. However, the chassis was not yet overloaded. The temperature of water in the cooling system did not go over 85 degrees, and the temperature of oil remained under 78 degrees. A slight decrease in mobility was not critical.

Changes to the hull were minor, which allowed the tank to replace the KV-1S in production.

The commission concluded the following:

"The commission considers it possible to recommend the KV-85 tank (KV-1S tank with partially altered hull and IS turret) for production instead of the KV-1S until IS tank production begins."

The final approval of the Object 239 was made after trials at the Gorohovets scientific research artillery proving grounds (ANIOP) conducted between August 21st and August 24th, 1943. It was clear that the D-5T surpasses the S-31 even before the firing began. The recoil length was only 240-300 mm, and the recoil brake was much easier to service. The turret of Object 237 was much more comfortable for the crew to work in, which improved the rate of fire. The Object 239 could fire at up to 10-13 RPM, which was twice as much as the Object 238.

Trials of the Object 239 at the Gorohovets ANIOP, late August 1943.

Trials at the Gorohovets ANIOP were more of an assurance than anything else. Stalin signed GKO decree #3891ss "On production of the KV tank with an 85 mm gun (KV-85)" on August 8th, 1943. This document confirmed that the Object 239 was selected. Production of the first 25 tanks was awaited in August. The advantages of the D-5 were demonstrated during the August trials of the SU-85 prototypes. Even though the D-5S-85 installed in the SU-85-II had a number of minor drawbacks, it was preferable to the design submitted by the TsAKB.

Object 239 after penetration trials, November 1943.

Trials of the Object 239 were not complete yet. First, the tank was submitted for reliability trials. In November of 1943 the tank was submitted for trials that changed its look. During trials of the PT8-15 sight, accepted into service as the TSh-15, the tank was hit by 76 mm proof and armour piercing shells fired from the ZIS-5 gun. The object of the trial was to determine the robustness of the system. The sight withstood being shot at from 300 meters, but the tank took some damage: the driver's hatch was knocked out and the commander's cupola was damaged. More trials awaited this tank, but those are best saved for another article.

Three months of worry

On August 12th the quota established by GKO degree #3891ss was reduced to 22 tanks. Even this small amount of tanks was not easy to produce. The factory had to wrap up KV-1S production, and, more importantly, produce 325 T-34 tanks, not including the SU-152, which had a higher priority than the KV-85. By August 26th no tanks had been delivered. The delivery was greatly expedited, and 16 tanks were accepted on August 31st. These bursts in productivity came at a cost. On August 31st a letter was sent to the GABTU from the senior military representative at ChKZ. He complained that a number of mistakes were made during the preparation of blueprints, which caused a dozen defects. Fuel tanks were modified by hand to be installed, as were racks for electrical equipment. Instead of new Multicyclone filters the old Vortox were used. There were big problems with sights. Factory #9 also introduced issues, not having supplied counterweights. The tanks that were already accepted had to be redone. As a result, the first 5 tanks were delivered only by September 9th. In September ChKZ delivered 47 tanks, including the 22 built in August.

Production KV-85, NIIBT, summer 1944.

Problems with the first production batch were mostly caused by subcontractors. Factory #200 began to ship hulls and turrets only on August 23rd. Factory #9 delivered the first 3 guns on August 28th, 17 on August 30th, and the last two in the morning of August 31st. There were other issues in addition to the counterweights that meant that more work had to be done on the guns. The situation repeated itself in September. As of September 19th only 6 tanks were delivered, 13 by September 24th. The factory had to once again rush to deliver the remaining tanks in the last days of the month. ChKZ made a delivery of 63 tanks, although not without issues. Problems with the aiming mechanisms were discovered.

The tank was somewhat different technically from its prototype.

The poor situation with technical documentation earned the involvement of the NKTP and GBTU. On October 6th, 1943, a resolution was passed on the approval of technical documentation for the KV-85. The GBTU did not accept a number of blueprint groups, including the fuel tank racks, turret traverse mechanism, and the intercom. A number of blueprints were accepted provisionally, such as the fuel system, air filter, hull, D-5T gun and coaxial machine gun mount, electric trigger, and sight mount. 20 of these groups were identified, of which some had to do with the Object 237 that was supposed to replace the KV-85 as of November 1943. ChKZ didn't fully agree with the changes requested by the GBTU, but the design of the tank was slowly improved.

Due to the brief production run KV-85 tanks were nearly identical.

The plan for October was the same as for September: 63 tanks. Continued issues with subcontractors resulted in the same problems as faced in August and September. The first 3 tanks were delivered only on October 10th, 7 by the 17th, and only 20 KV-85 tanks by October 22nd. 56 were ready by October 56, the rest were rushed to completion. 67 KV-85 tanks were shipped in October, the remaining 34 were shipped in early November.

By then ChKZ had put the IS-85 into production. The first tank of this type was delivered on November 5th. This was also a temporary measure, as soon the IS-122 (IS-2) with a 122 mm D-25T gun replaced it.

The KV-85 was not fondly remembered. N.F. Shashmurin called this tank а "bobtail" in his memoirs, implying that its time was short. In his opinion, Kotin pushed it through as the simplest development of the KV-1S tank. Of course, memoirs should be approached critically, especially considering the complex relationship between Kotin and Shashmurin, but Nikolai Fedorovich's words are confirmed by some documents. The dramatic situation with the tank's production confirmed that Kotin's opinion regarding this modernization as the simplest solution was incorrect. Even a more or less ready chassis did not prevent issues with the transition from the KV-1S to the KV-85. 148 tanks produced over 3 months cost the factory staff a lot of worry.

Limited success

Major deliveries of the KV-85 began starting with late September of 1943. On September 23rd a train was sent to Kosterevo with reinforcements for the 27th Guards Tank Regiment. The tanks were sponsored by workers from Chuvashia and were a part of the "Chuvashian Kolkhoz Worker" tank column. The KV-85 was also shipped to the 7th, 14th, 28th, 30th, and 34th Guards Tank Regiments. The structure of these tanks was the same as for regiments equipped with the KV-1S. The TO&E authorized 21 tanks per regiment. This allotment remained until the end of the war. In early 1944 regiments armed with heavy tanks were renamed to Guards Heavy Tank Regiments.

This KV-85 in winter camo shows signs of active use. Winter 1944.

The study of new tanks went at different rates. It was simplest for units that had already used the KV-85, as the difference between the two was slight. However, some units were used to different tanks. For instance, the 34th Guards heavy Tank Regiment where 21 tanks were shipped on October 22nd, 1943, previously fought using Churchill IV tanks. Tankers of this unit had issues with the long gun barrel hitting trees. This regiment was the first to use the KV-85 tank in battle.

As it often happens, the first results were a mixed success. On November 20th, 1943, the 28th Army of the 4th Ukrainian Front was reinforced with the 34th Guards Heavy Tank Regiment and 40th Heavy SPG Regiment (with SU-152 SPGs). By 08:00 the regiments were prepared to fight. At 09:40 both regiments were given the order support the 9th Rifle Corps in its attack to break though the enemy's defenses, capture Malaya Lepetikha, and establish a crossing across the Dnieper. 20 KV-85 and 9 SU-152 took part in the attack. The SU-152 broke away from its infantry and ran into Ferdinand tank destroyers from the 653rd Tank Destroyer Battalion. The KV-85 attacked at the same time, but without infantry support their attack was also ineffective. The 40th regiment lost 6 SU-152s knocked out and 1 burned, the 34th regiment had 9 KV-85 tanks knocked out and left in enemy hands.

This tank was knocked out in late 1943.

The battle continued on the next day, and the Ferdinands counterattacked at 13:20. The SU-152 took their revenge, destroying 2 Ferdinands and 3 tanks. By the morning of November 22nd the 34th regiment had 9 battle ready KV-85s, the 40th regiment had 5 SU-152s, and 7 by the 25th. By the end of November 29th the regiment had 8 functional KV-85 tanks left. In this time the regiment destroyed up to 300 enemy soliders and officers, 2 anti-tank guns, 3 tanks, and 2 tank destroyers. Complete losses included 12 KV-85, 8 more were evacuated for repairs. 16 tankers died, 32 were missing, and 16 were wounded.

The SU-152 were more effective. Their unit claimed up to 250 infantrymen, 2 tanks, 9 SPGs, 18 anti-tank guns, 8 field guns, and 10 mortars. 4 SU-152 were lost irreparably, 6 were knocked out, but later repaired. 8 SPG crewmen were killed, 16 were wounded.

Considering the enemy of the new tank, the losses were not so horrible. Keep in mind that claims were exaggerated on both sides, and that a knocked out and burned out tank are two different things. The Germans like to recall only the battles of November 26-27th, claiming that 54 Soviet tanks were destroyed. Of them, 21 were claimed by the crew of Franz Kretschmer. However, the Iron Cross holder should have been more conservative. On November 26th the armoured forces of the 28th Army lost 8 tanks, of them only 5 were burned out, and on the 27th 25 in all. No matter how the losses are tallied, the number 54 cannot be obtained.

Captured KV-85 from the 34th Guards Tank Regiment, late November 1943. The tank was used by the 653rd Tank Destroyer Battalion.

The KV-85 faced Tigers too. The 7th Guards Tank Regiment received KV-85 tanks on October 28th, 1943. After restructuring in Tula, the regiment was sent to join the 60th Army of the 1st Ukrainian Front. The regiment went into battle on November 23rd, several days after the 34th regiment. The tankers took part in a defensive operation in the Kiev direction. On December 9th the bloodied regiment was transferred to the 38th Army. 9 KV-85 tanks remained by the end of January.

Their finest hour took place on January 28th, 1944. On that day, at 16:35, a group of 35 German tanks supported by infantry moved out towards the Telman sovkhoz farm. Soviet intelligence showed that the 1st SS Division was taking part in this attack. 60 men were defending the farm with 2 KV-85 tanks and 2 SU-122 SPGs in support commanded by Senior Lieutenant I.L. Podust. By Soviet data, the Germans lost 5 Tigers, 2 PzIVs, 3 PzIIIs, 7 APCs, and 6 anti-tank guns as a result of three failed attacks. After the enemy surrounded the farm, Podust evacuated the defenders. For this battle he received the Order of the Red Banner.

The most effective crew was commanded by Lieutenant S.I. Kuleshov, who destroyed 2 Tigers and one PzIV. When the Germans attempted to get close, the tank crushed about 15 of them with its tracks, the rest ran off. His reward was the Order of the Patriotic War 2nd Class. Another Tiger was claimed by the SU-122 crew commanded by Guards Lieutenant V.F. Mikheev.

KV-85 in Crimea, 1452nd SPG Regiment, May 1944.

The end of 1943 and early 1944 was the peak of the KV-85's career. The small amount of tanks produced and heavy losses meant that these tanks were a big rarity by the summer of 1944. For instance, in the spring of 1944, 11 KV-85 tanks remained in the 1452nd SPG Regiment, which took part in the liberation of Crimea. Individual tanks were seen in various units in the summer and fall of 1944, but these were the last bursts of activity. Not a single mass production tank survives to this day, but the Object 239 is on display in Avtovo, St Petersburg. However, it was "improved" by welding on a bow MG before it was installed.

Original article by Yuri Pasholok.

Walkaround of the Object 239 monument in Avtovo

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Wishlist Response

December 9, 2019, 1:53 pm

≫ Next: Leningrad People's Militia

≪ Previous: Kotin's Bobtail

"To the Marshal of the Armoured Forces, comrade Fedorenko

The tactical-technical characteristics that you sent are viewed by us as a task to develop new prospective types of heavy tanks that are not yet put into practice in tank building.

As you do not have any objections regarding the requirements for the IS-6 that I approved and confirm that it is necessary to build such the IS-6 with a mechanical transmission, I consider that it is at the same possible to build a tank with an electrical transmission using the same requirements.

Development of a tank with an electrical transmission will allow us to demonstrate the advantages and specifics of this transmission compared to a mechanical transmission and determine its potential in the creation of more powerful tanks.

We have the following notes about a number of tactical-technical requirements that you provided.

The requirements for protection and equal armour from all sides are at odds with the required weight of the tank. Based on the calculations of NII-48, the following thicknesses will be required for the specified resistance:

Plate	IS-6		Calculated
Plate	Thickness	Angle	Thickness	Angle
Upper front	100	65	130	65
Lower front	100	60	130	60
Upper side	100	45	170	45
Lower side	100	0	207	0
Upper rear	60	60	130	60
Lower rear	60	25	207	25

Thus, if the overall layout and slope of the IS-6 is preserved, the mass of the hull and turret will be at least 50-55 tons, giving a tank that weighs 75-80 tons overall instead of the 50-55 that are specified in the requirements.

Experience in battle does not confirm the requirement for equivalent all-round protection. A 75-80 ton tank will also be very difficult to transport.

The requirement for protection from HEAT shells of all calibers is unreasonable, as this will require spaced armour that will increase the weight of the tank further. The spaced armour will be destroyed by the first hit to the tank.

The installation of a 122 mm gun with a muzzle velocity of 1100 m/s will not be possible in the near future. No such gun is being produced or has been designed. The creation of such a gun will take a long time.
Using one piece ammunition for this gun is irrational, as the mass of 45 kg (approximate) and length of 1.5 meters will create significant difficulty in loading the tank and will not allow us to achieve the rate of fire requirement (4-6 RPM).
The creation of a 1000 hp tank engine is problematic, as there is no such engine at this time. Development and tuning of the engine will take a long time, 1.5-2 years. It is senseless to delay the creation of a new tank for this long, especially since the required mobility for this tank can be achieved with a 700-750 hp engine.
The installation of a gun stabilizer is senseless and unprofitable:

The rate of fire of the 122 mm gun will be limited by the reload time, not the aiming time. The application of a stabilizer will not increase the effective rate of fire.
Calculations show that the stabilization of a 122 mm gun will require either two STP-85 gyroscopes (currently tested on the T-34-85) or one that is twice as powerful. All components of the stabilizer will be so massive that it will be difficult for the crew to work in the turret.

The installation of two belt-fed machine guns on the fenders will increase the firepower of the tank, but the lack of ability to service them in battle (resolve jams, etc) will reduce the effectiveness, and therefore it is more rational to install one gun inside the tank.
The specified fording depth cannot be achieved, as the tank hull will be significantly less than 2 meters in height. Equipping a heavy tank for underwater driving is a completely separate issue.
The requirement to allow the driver to drive "without headlights" is confusing. All known night driving devices require IR emissions from the headlights. It is also worth considering that multiple trials of nighttime driving devices did not give good results and cannot be recommended for installation.
The CO ventilation requirement is excessive.
The requirement for a "6-8x binocular gun sight for the right eye" is unclear. Existing binocular sights, both foreign and domestic, have the same magnification for both eyes.
The NKV informs me that creating a binocular sight with different magnification for either eye is impossible and pointless. The 8x magification will also reduce the field of view and is pointless.

Based on the above, I consider that your requirements should be reworked with the incorporation of our notes.

V. Malyshev

August 8th [1944]"

CAMD RF 38-11355-2243 pp.148-150

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Leningrad People's Militia

December 10, 2019, 1:49 pm

≫ Next: Inspection

≪ Previous: Wishlist Response

I've previously looked into the effectiveness of the Leningrad People's Militia units hurriedly raised in the summer of 1941. The popular narrative is that they were composed of semi-unarmed expendable "volunteers" sent into the meat grinder to stall the Germans, but the documents tell a different story. Aleksey Isayev confirmed my suspicions.

"Based on surviving documents that can be accessed today, the Leningrad militia was armed to the teeth, specifically the Leningrad militia of 1941 that moved out to the Luga line and the Guards divisions that fought closer to Leningrad proper. They were armed well according to the TO&E and had mortars above that, which were produced in Leningrad and were naturally issued in droves to their militia. In addition, they were given improvised Izhora armoured cars. Ordinary trucks were equipped with armour, they didn't have turrets, but they had armour to protect from shells, splinters, and bullets and they had machine guns. These were very predatory looking cars and periodically you can see them in eBay photos, the Germans took photos of them when they knocked them out, sadly there are few photos from our side.

So the Leningrad militia was well armed, decently trained by the standards of 1941, and had high morale. The Leningrad militia that played an important role in holding the Luga line, especially the approaches to Ivanovsk and Sabsk. I would say they played a key role there. Based on how the front line moved, the militia fought with the same skill as cadets. Cadets were fighting nearby and the resilience of the militia was equivalent to that of the cadets, which is impressive.

Let's say you don't believe Soviet documents and you think it's all lies and fraud by damned Stalinists. There are German documents, including interrogations of prisoners captured in battle with the militia, they write that everyone had a rifle, a gas mask, ammunition, and the fact that they were well armed is confirmed. The fact that the Germans decided to cancel the assault on Leningrad envisioned by Barbarossa is, in no small part, an achievement of the militia on the Luga line, specifically in July and in August when the Germans attacked and the offensive developed very slowly, slowly enough that it became clear that the planned assault will not go forward."

Aleksey Isayev, Tactic Media Q&A Stream October 8th, 2019

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