T-50's Growing Pains

"To the People's Commissar of Medium Machinebuilding, comrade Malyshev

I report that the proving grounds trials of the experimental prototypes of the T-50 tank cannot be completed in the time set by your order #009ss issued on January 7th, 1941, because of the design defects discovered during the trials.

The main defects of the tank are as follows:

Priest Reliability

The following excerpt is taken from the AFV(T) Mediterranean Area Technical Report No.26, dated February 26th, 1945.

"Priest

Engine life

The average life of the engine in one unit is 225 hours, which is equivalent to about 900 miles. Some engines have done 300 hours. In no case has the unit removed an engine from the vehicle and carried out a proper 100 hour overhaul, but they have done all that can be achieved with the engine in situ. It has been pointed out that the proper 100 hour check is of the greatest importance and would definitely lead to a longer engine life. With this the unit agreed, but said that the time was never allowed for them for such a procedure. From visits paid to other Priest and Sherman regiments, this seems a general complaint."

These numbers are fairly interesting, since they can be compared with the mad dash for Berlin on the other side of the front. There, T-34s were racking up 2000-2500 km and 250-300 hours without overhauls. Mere days after this decree, the minimum (not average) lifespan of T-34 engines was increased to 250 hours.

Experiments

"To the Chief of the 11th Department of the ABTU

Summary of experimental work performed at the T-2O plant in December of 1938

January 3rd, 1937

#12s

1. Installation of remote control equipment on BT-7 tanks

One BT-7 tank with remote control went through factory trials. The vehicle made two outings, travelling 200 km during each one. The first trial was not completed due to loss of air pressure. Pressure was lost because the hose leading from the air tank to the compressor burst and the liner of the air cylinder of the final drive was punctured. 

The second trial was not completed due to a breakdown of a differential gear. The following drawbacks were recorded during trials.

Sherman Tracks

"To the Chief of the GBTU Tank Directorate, Engineer-Colonel comrade Blagonravov

I additionally report on the issue of quality of M4A2 tanks with modernized suspension. After informing the Americans that M4A2 tanks with serial numbers less than #64926 have defective tracks, serial numbers of tanks in possession of the 16th OTP and the department were checked.

As of May 25th, 1945, the department and regiment have a combined total of 177 M4A2 tanks with modernized suspensions. All 177 tanks have serial numbers below #64926. These are the tanks whose tracks are considered defective.

Spare Parts

"Order of the People's Commissar of Medium Machinebuilding of the USSR #320ss

Moscow

July 12th, 1941

To ensure timely delivery of spare parts for KV and T-34 tanks to their destinations and reduction of tank repair times, I order that:

1. Kirov factory director comrade Zaltsmann and Chelyabinsk Tractor Factory director comrade Shor must send a full set of parts with every 7 KV tanks according to attachments 1 and 2.
2. Factory #183 director comrade Maksarev and Stalingrad Tractor Factory director comrade Dulkin must send a full set of parts with every 10 T-34 tanks according to attachments 3 and 4.
3. Factory #75 director comrade Kochetkov must send a full set of parts with every 7 V-2K diesel engines sent to Kirov and Chelyabinsk factories and 10 V2-34 engines sent to STZ and factory #183 according to attachments #2 and 4.
4.  
1. All parts and assemblies listed (section 1 of attachments) will be debited to the NKO parts list for the plan of the second half of 1941.
2. Components and assemblies received by factories from subcontractors will be debited to the NKO by GABTU representatives.
5. Begin equipping vehicles with spare parts immediately upon receiving this order.

Signed by S.A. Akopov on behalf of Deputy People's Commissar of Medium Machinebuilding of the USSR, V. Malyshev"

RGAE 8115-8-83 p. 52

Prewar Prototypes

"November 11th, 1939
#0830/s

To the Chief of the 8th Department of the ABTU, Military Engineer 1st Class comrade Afonin

Report on the trials of the A-32 (weight down) and preparations for trials of the A-20 and Voroshilovets tractor

1. The A-32 (second prototype) weighed down to the weight of an A-34 has travelled 1047 km. During the third march, the average moving speed off-road was no more than 20-23 kph. This was caused by terrible conditions of the terrain (mud). Typically, the vehicle can only drive in second gear off-road. The transmission is working well in these conditions, there haven't been any defects. A trip on a highway is planned on November 10th to test the running gear.
2. Presently, A-20 components (improving the wheeled drive transmission) are undergoing mechanical finishing.
3. Despite our insistence, Voroshilovets tractors are not being worked on at all. Management of department 500 claims that its equipment is occupied with other projects (A-7, D-3, D-5, etc). This situation may result in the Voroshilovets tractor not being ready for mass production by January 1st, 1940.

Military representative of the RKKA, Military Engineer 3rd Class, Baikov."

RGVA 31811-3-1632 p. 33

T-70B: A Light Modernization of a Light Tank

GKO decree #1394 "On production of T-70 tanks at the Molotov Gorkiy Automotive Factory" was signed on March 6th, 1942. Work on improvement of the T-60's armament resulted in a completely new tank that used many of its predecessor's components, but was superior to it in every respect. Of course, it was not a perfect replacement for the T-50, which fell victim to production issues. Nevertheless, it was suitable for the role of a light tank. The T-70 became the second most produced light tank, after the American Light Tank M3 family. This article tells the story of the T-70B, the modernized version of the light tank.

Pershing: Heavy by Necessity

The British Churchill tank was the only one supplied to the USSR by the Western Allies en masse. The US had bad luck with heavy tanks. Work on the Heavy Tank M6 hit a dead end. Nevertheless, heavy tanks did arrive in the American army by the end of the war. These were Heavy Tanks T26E3, standardized as M26 Pershing. However, the T26E3 was rather arbitrarily classified as heavy. In practice, this was a medium tank. Only its mass made it a heavy, and even then, it returned to medium after the war. This article is dedicated to the trials of the T26E3 in the USSR, during which it was compared to heavy tanks.

Engine Prejudice

By 1943, it was clear that the Canadian Ram tank could not keep up with the Sherman. The AFV Users Committee of the First Canadian Army was willing to switch to the Sherman, but their requirements were clear.

Less Armour, More Mobility

The gradual increase of a tank's mass is a normal and logical occurrence. Mass grows, first of all, due to thicker armour. During WWII, the thickness of tank armour grew several times over. However, there was one case where designers had to sacrifice armour. This case was the Soviet KV-1S tank, which was, in many ways, a necessary compromise, taken to resolve serious issues with the KV-1's reliability. The vehicle left a mark in the history of Soviet tank building. The KV-1S appeared as a result of a change of perspective in Soviet heavy tank doctrine. Mobility started to play a more important role. The new tank was not just a lighter KV-1, but had a large amount of new technical solutions. What is the history of the KV-1S, and why was its journey into production so difficult?

Churchill Problems

The following document is dated March 1942.

"Churchill I and II tanks

The following points need special attention while working with the aforementioned tanks.

1. Engine
1. In order to reduce the chance of the cast iron clutch socket cover, part Z.V.1/BB/44365, the engine RPM should never rise above 2000 RPM. It is possible that some engines are limited below this number, but most are set at 2400 RPM.
   A new type of cover is made from cast steel.
   

Improved Tractor

"To the Chief of the 3rd Departmetn of the GAU UMT

Engineer-Major comrade Bozilenko

On the issue of trials of the ATZ-3T tractor

I inform you in this letter that the ATZ-3T tractor, designed and assembled at the ATZ on the 1TA tractor base was subjected to factory trials and drove for 400 km along various roads and mountain terrain. The tractor was assembled by means of mounting new components on an altered chassis of a prior experimental tractor. The gearbox and other transmission mechanisms, suspension, and other components were taken from an existing tractor without changed, and had already worked for 700 hours. The altered components of the tractor worked well, without breakdowns or defects, and are in good condition even now.

Hammer Time

Here are some document excerpts regarding the PTRD bolt-action anti-tank rifle, that a lot of modern milsurp collectors might feel empathy with.

"Recent reports from the fronts, regions, and armies remark on cases where Simonov and Degtyaryev ATRs do not work

...

Experience shows that when using PTRs in summer conditions, even when maintaining them according to section 1, there are rifles that do not extract freely. In order to continue use of the weapon, authorize soldiers to apply wooden mallets."

"Experimental PTRD from factory #74. 610 rounds were fired in various conditions, and 189 extractions (31%) had to be performed with a mallet. The report stated "This PTRD works unsatisfactorily in any conditions". Another PTRD from the factory earned the review "This PTRD works exceptionally unsatisfactorily in any conditions". Out of 275 shots, 264 needed a wooden mallet (96%).

The third PTRD managed to surpass that result. "The lifetime of the rifle was 43 shots. Every extraction needed the mallet. After extracting the 43rd casing, the bolt handle fell off."

Via Andrei Ulanov.

Tetrarch Overview

"Office of the Commander of the Armoured and Mechanized Forces of the North Caucasian Front

August 9th, 1943

To the GABTU BTU Chief, Engineer-Colonel Afonin

In reply to your inquiry, I report the tactical-technical characteristics of the British MK-7 tank:

1. Full weight: 8.0 tons
2. Main dimensions:
1. Length: 4.0 m
2. Width: 2.4 m
3. Height: 2.17 m
4. Clearance: 0.4 m

KV-1S Road Wheels

"Report on KV-1S Road Wheels

Kirov factory KV-1 tanks used cast road wheels with Г-shaped rims. As a part of the total requirement for weight reduction, the weight of the road wheels would be reduced by changing the shape of the rim. A T-shaped rim was selected, which gave the same robustness at less weight.

Two of the first KV-1S tanks produced at the Kirov factory, #15001 and #15002, with T-shaped road wheel rims, ribs, and round openings in the disks were provided for trials.

Tank Trailers

"Minutes of a meeting at the 5th Department of the GABTU BTU with representatives of tank units on the issue of trailers for tanks proposed by factories #592 and #112

The meeting was led by the Chief of the 5th Department of the BTU, Military Engineer 1st Class, comrade Afonin.

Afonin: We gathered representatives of tank units by order from Army Commissar 2nd Class Biryukov to discuss the proposal of engineers from factories #592 and #112 to build trailers for tank riders. [Reads proposal from factory #112 and explains technical issues connected with factory #592's proposal].

Reliability and Repairs in the 2nd Tank Army

At the beginning of the 2nd Tank Army's offensive during the Battle of Kursk, on July 16th, the army's technical services performed an inventory of their vehicles' remaining service life.

Type	Number	Of those, functional	Remaining engine hours
			under 50	50-100	150-200	over 200
T-34	276	238	-	167	71	-
T-70	109	92	-	67	25	-
T-60	17	16	-	16	-	-

Pz.Kpfw.II Ausf. c-C: At the Spearhead of Blitzkrieg

The story of the PzII tank was an unusual one. In many ways, it owes its "accidental" existence to the attempts of mounting a 20 mm autocannon in the Kleintraktor (future PzI). Due to issues with production of the Z.W. tank (future PzIII), the PzII was the most numerous front line tank for the first two years of WWII. Germany's most common tank was not even originally included in the armament plans.

Pz.Kpfw.II Ausf.a through b: An Unplanned Tank

The light PzII tank played an important role in the structure of the German tank forces. Despite the opinion born of German generals' memoirs, this was not a training tank. On the contrary: at the time of its inception, the PzII was one of the best light tanks in the world. It appeared almost by accident, but occupied a significant part of the Wehrmacht's order of battle. The PzII remained in production for five years, with some small breaks. What is the history of the PzII, and what did its first versions look like?

M4A2(76)W: Emcha With a Long Hand

The Americans considered improving the firepower of the Medium Tank M4 back in September of 1941. A year later, experiments with installing the 76 mm T1 gun into the stock turret commenced. Even though the gun fit, the military was unsatisfied with this rearmament. A decision was made to equip the M4 with the turret from the Medium Tank T23, which did not enter production. This was not hard, since the turret ring diameter was the same.

Shortly before that, the M4 (known in the USSR under the nickname "Emcha") was equipped with wet ammunition racks. These modernized tanks, whose name received the suffix (76)W, went into production in January of 1944. Among them was the M4A2(76)W, the production of which began in May of 1944. The USSR received these tanks under the Lend Lease program.