Monday, 18 November 2019

Experimental Work at Factory #183 March 1941

"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
  1. Trials of cooling fans: three types of cooling fans entered trials.
    1. 1st variant: instead of blade supports special ribs were used. A vehicle with this fan travelled for 800 km. Trials will continue in April.
    2. 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.
    3. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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"

Saturday, 16 November 2019

A Barrel Too Long

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.

Thursday, 14 November 2019

Pistol Power

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.

Wednesday, 13 November 2019

Small Arms

"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
Light bullet
AP-I bullet
Tracer
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"

Tuesday, 12 November 2019

On to Tallinn

"Award order
  1. Name: Gorban, Vasiliy Moiseyevich
  2. Rank: Major
  3. Position and unit: commander of the 2nd tank battalion, 152nd Leningrad Independent Tank Brigade.
  4. Year of birth: 1916
  5. Nationality: Ukrainian
  6. Party affiliation: VKP(b) member
  7. Participation in the Civil War and subsequent action in defense of the USSR or in the Patriotic War: in the Patriotic War since June 22nd 1941, Leningrad Front
  8. Wounds and contusions in the Patriotic War: wounded twice lightly in 1941, once heavily and once lightly in 1942
  9. In the Red Army since: 1937
  10. Recruited by: career officer
  11. Prior awards: Order of the Red Banner, Order of Aleksandr Nevskiy, Order of the Red Star, Defense of Leningrad medal.

Monday, 11 November 2019

7.5 cm KwK 42 Penetration Table

I've posted a number of these diagrams before, for instance here is one for the Pak 40. The set of images for the more powerful KwK 42 is unfortunately incomplete and only available in low resolution, but I am including it for completeness sake.


The Valentine is not surprising at all. The armour piercing ammunition can penetrate any surface from up to 2000 meters. HE can knock off the tracks.

Saturday, 9 November 2019

First Try at a Medium Tank

To a casual observer, German tank industry was like a jack in a box. 15 years after the end of WWI it suddenly sprang to life and began to crank out world class designs. However, there is no such thing as miracles. In addition to German specialists like Joseph Vollmer and Otto Merker who worked abroad, Germany had its domestic tank program. It was conducted in secret and birthed some very unconventional designs. One of them was the Grosstraktor, a medium tank that became the culmination of German tank building of the 1920s. It was the first step on the way to the PzIV, the most numerous German tank of WWII.

Thursday, 7 November 2019

Small Arms Feedback

"HQ of the 27th Rifle Division
Dept 1
November 14th, 1945
#1/0793

To the commander of the 132nd Rifle Corps

I present my notes and conclusions on infantry weapons, ammunition, and preparation of infantry based on experience in the Patriotic War of 1941-45.
  1. Notes on design.
    1. TT model 1930 pistol: has design defects. The center of mass is bad (almost in the center of the pistol), it must be closer to the handle, like the Borchardt-Luger pistol. It is desirable to reduce the mass to 800-850 grams, change the shape of the pistol grip to make shooting more comfortable, and increase the angle between the barrel and handle.

Wednesday, 6 November 2019

Finnish Zimmerit

"Copy from a copy
For service use only
Translated from Finnish

Methods of combat against anti-tank magnetic charges

The British, Americans, and also the Russians use magnetic charges, especially against tanks and cars. They are supposed to stick to metal including painted metal or armour.

Report: this is likely a device of British origin, shaped like a half-cylinder 14 cm in length made of artificial materials and filled with explosives. The flat half has 4 magnetic poles. The curved half has an 8 cm deep slot for the fuse and detonator. The fuse is held in place with a cap that screws in.

The knife-shaped delayed fuse is 11 cm long and 1 cm in diameter. Two captured delayed fuses show that they cam go off in an hour or in 3 days. It is possible that other time settings exist.

Tuesday, 5 November 2019

Lessons Learned

"Secret
To Comrade Beria
January 27, 1944

Based on the recommendations given by the commander of the 3rd Ukrainian Front, Army General comrade Malinovskiy, we report that:
  1. Item 1 in comrade Malinovsky's letter proposed installation of spaced armour 30-50 mm thick on the SU-85 and SU-122 SPGs.
    We consider that it would be unacceptable to install 30-50 mm thick spaced armour on the SU-85 and SU-122 SPGs on the T-34 chassis due to excess weight and overloading of the front suspension, which would radically reduce the lifespan of the transmission and running gear.
    An experimental SPG with a 100 mm gun is being built which will have 75 mm of front armour. Trials will show how feasible this undertaking is.

Monday, 4 November 2019

Quality Control

"American Embassy in Moscow, Military Mission 
January 13th, 1944

To the Tank Directorate
M4A2 Medium Tank

For your information, we attach the aforementioned list of difficulties encountered by our personnel with M4A2 tanks of the latest type. We also send you methods of resolving these issues.
  1. Turrets of many tanks are poorly fitted, therefore turning them in order to fire on the move is difficult. This usually happens due to incorrect installation of the turret ring and due to incorrectly assembled liners of the traverse mechanism. There should be a liner between the mount of the case and the turret wall. The thickness is chosen such that the space between the gear teeth is minimal, 0.002"

Saturday, 2 November 2019

Heavy Tank, Italian Style

In the mid-20th century heavy tanks were a sign of membership in an elite club of tank building nations. Many nations attempted to make these tanks, but failed. Even if a heavy tanks was made, it did not always make it to the war, like the American Heavy Tank M6. Only four nations mass produced heavy tanks that made it to the battlefield: USSR, Germany, Great Britain, and Italy. The British Churchill was officially an infantry tank, and the Italian Carro Armato P 40 was only heavy on paper. The Italians never even got to use their tanks in battle, as they fell to the Germans.

Thursday, 31 October 2019

"Tiger" or "Elephant"?

The Tiger tank first saw battle in the USSR in the fall of 1942, but its debut was unnoticed. The Red Army first inspected one of these tanks in early 1943, but verifiable information was rare. For the time being its name was not "Tiger", but "Elephant", named after the elephant emblem painted on its armour.

"April 20th, 1943
To the commander of the anti-tank rifle company

In addition to the description of the "Elephant" German tank sent earlier, find attached photographs of the "Elephant"

Chief of the [illegible] 48th Independent Mechanized Brigade
Captain [signature]

Wednesday, 30 October 2019

Comrade Sherman

"Award Order
  1. Name: Sherman, Yevgeniy Grigoryevich
  2. Rank: Jr. Lieutenant
  3. Position and unit: T-70 tank commander, 2nd tank battalion, 120th Orsha Independent Tank Brigade.
    Is nominated for the Order of the Patriotic War 1st Class (posthumously).
  4. Year of birth: 1924
  5. Nationality: Jewish
  6. Party affiliation: none
  7. Participation in the Civil War, subsequent combat in defense of the USSR: Patriotic War, Western Front, as of August 13th, 1943
  8. Wounds or contusions in the Patriotic War: did not have any
  9. In the Red Army since: March 6th, 1942
  10. Recruited by: Samarkand recruitment office
  11. Prior awards: none

Tuesday, 29 October 2019

Night Rider

"To the Deputy Chair of the State Committee of Defense of the USSR, comrade Molotov
August 2nd, 1942
#408027s

According to GOKO decree #175ss issued on May 15th, 1942, the Special Design Bureau of the All-Union Electrotechnical Institute produced and presented by July 15th, 1941, one sample of a device for driving tanks at night.

The device was installed on a T-34 tank and tested at the Research Proving Grounds of the Main Auto-Armour Directorate of the Red Army..

The results of the trials showed that the tank can be driven at night with a closed hatch on a highway or on a dirt road at a speed of 10-12 kph.

The sensitivity of the fiberoptic elements in the prototype is insufficient and the IR lights (headlights) do not proving a sufficiently wide beam which does not offer sufficient visibility through the device.

The night driving device based on the principle of transforming IR light into visible light has one significant drawback in that the light from signal lights (stoplights) can only be seen in one colour.

All colours (red, yellow, blue, white) can be seen through the device from a long distance away, but only as bright green dots.

These drawbacks limit the usefulness of this device for driving tanks.

In order to read a final judgement regarding the use of this device in the military it is necessary to produce a trial batch of the devices with the aforementioned defects corrected. 

Attached is a draft GOKO decree to order the production of a trial batch of devices for night driving. I ask you to approve it.

GABTU Military Commissar, Army Commissar 2nd Class, Biryukov"

Monday, 28 October 2019

Never Penetrated in Combat

Fans of German armoured vehicles often claim that the Tiger II was the ultimate in armoured vehicles of WWII. Particularly, one claim is often made: its upper front plate was never penetrated in combat (even though it was penetrated in testing by several types of guns). Indeed, as this vehicle is rather rare, few photos of them with battle damage exist at all, let alone ones with a visible hole in the UFP. There is one, however.

Saturday, 26 October 2019

Workhorse of the Italian Army

Stereotypically, Italian tank forces were filled with antiquated designs that broke down constantly. Reality is somewhat more complicated. It's true that Italy fell behind in the arms race, but this happened closer to 1942 or even 1943. In 1940-41 Italian tanks were on par with British tanks, or sometimes even surpassed them. The Carro Armato M 13-40 was comparable to British cruiser tanks that it shared the front line with.

Friday, 25 October 2019

Designing the T-34

My first book, Designing the T-34: Genesis of the Revolutionary Soviet Tank is available for purchase! It is currently available at the publisher's website or Amazon. Some regional Amazon sites still have it listed as a preorder, but Morton's is already shipping copies. An ebook is planned, but there is no concrete release date, so for now your only chance to get it is a good old fashioned paper copy.

It is printed in A5 format on 92 pages of glossy paper with 100 images, including full colour modern photos, blueprints, and black and white archive photo, plus 8 colour profiles by artist Thierry Vallet. 



Thursday, 24 October 2019

What's In A Name?

When the T-44 was created, the 85 mm gun was already insufficiently powerful. One solution was to install a 100 mm gun, but a widened turret ring was required. The result was the T-44B tank, which eventually evolved into the T-54.

"To the People's Commissar of Tank Production of the USSR, comrade Malyshev

Factory #183 developed a modernization of the T-44 tank with reinforced armour and a 100 mm gun installed on a 1800 mm wide turret ring.

According to my information the lead designer of factory #183 comrade Morozov has already arrived in Moscow with the project materials.

I ask you to instruct comrade Morozov to deliver the materials to the Tank Directorate for review and evaluation of the T-44B project.

Deputy Commander of the Motorized and Armoured Forces of the Red Army, Colonel-General of the Tank Forces, Korobkov.
November 2nd 1944"

Wednesday, 23 October 2019

HEAT Issues

"TO: Commanders of Artillery of Rifle Corps, Rifle Divisions, and Artillery Regiments

29th Rifle Corps only

On the causes of premature detonation of 122 mm HEAT rounds

Several cases of premature detonation of HEAT (armour burning) ammunition in barrels of model 1938 122 mm howtizers with the subsequent destruction thereof have been recorded in 1944. Investigations show that in half of the cases firing was done with the full propellant charge instead of #4 charge as required by the firing tables for HEAT ammunition.

Tuesday, 22 October 2019

Casting in Omsk

"Requirements for T-34 castings cast in the 2nd quarter of 1942 at factory #200 for factory #174

Item
# per set
Weight per unit (kg)
Weight per set (kg)
Items in 2nd qtr
Total weight in tons
In April
In May
In June
From 8S armour steel
Final drive cover
2
273
546
250
66,850
-
100
150
DT shield
1
136
136
100
13,600
-
40
60
Right crankcase shield
1
80
80
100
8,000
-
40
60
Left crankcase shield
1
80
80
100
8,000
-
40
60
Exhaust pipe shield
2
65
130
200
13,000
-
80
120
Front plate connector beam
1
187
187
100
18,700
-
40
60
Driver’s hatch
1
186
186
100
18,600
-
40
60
Gun shield
1
304
304
100
30,400
-
40
60
Turret
1
3000
3000
100
300,000
-
35
65
Subtotal


4649

477,150

175 tons
302.1 tons
From SL-2 or 40SG high carbon steel
Final drive clutch outer drum
2
66
132
200
13,200
-
80
120
Final drive clutch inner drum
2
41
82
200
8,200
-
80
120
Wheel hub
10
30
300
1200
36,000
-
600
600
Idler disk
2
88.5
167
300
26,550
-
120
120
Right crankcase
1
124
124
100
12,400
-
40
60
Left crankcase
1
124
124
100
12,400
-
40
60
Right carrier
1
30.5
30.5
100
3,050
-
40
60
Left carrier
1
33.5
33.5
100
3,350
-
40
60
Swing arm carrier
8
24
192
800
19,200
-
320
480
Right idler carrier
1
66
66
100
6,600
-
40
60
Left idler carrier
1
66
66
100
6,600
-
40
60
Subtotal


1317 kg

147,500

62.55 tons
85 tons
Total


5966

624,700

237.55 tons
387.16 tons

"

RGAE 8752-1-9 p.46