Wednesday, 21 June 2017

ZIS-5, Take One

"May 30th, 1941
To the Central Committee of the VKP(b)
Comrade Zhdanov

According to USSR SNK and Central Committee Decree #1216-502 issued on May 5th, 1941, two experimental T-44 tanks built by factory #183 are supporsed to be armed with the 76 mm ZIS-5 or 57 mm ZIS-4 gun. The main characteristics of these guns is shown in the following table:

Gun model
Caliber in mm
Muzzle velocity, m/s
Shell mass, kg
Penetrates armour
At 0 degrees
At 30 degrees
Thickness in mm
Distance in m
Thickness in mm
Distance in m
F-34
76.2
662
6.3
60
Up to 1000
50
Up to 1000
ZIS-5
76.2
813
6.5
90
Up to 1000
70
Up to 1000
ZIS-4
57
992
3.14
90
Up to 1000
70
Up to 1000

Tuesday, 20 June 2017

Torsion Bar Trials

"Methodology of Torsion Bar Trials

The trials were split into stages:
  • Motion trials of torsion bars.
  • Lab tests of materials (static and spring fatigue).
  • Lab static destruction tests of torsion bars (by twisting).
  • Analysis of various layouts of torsion bar suspensions and issues connected with them.

Monday, 19 June 2017

KV Gun Upgrades

"The following work is necessary to perform trials of KV tank armament and improvement of blueprints:
  1. Install the F-34 gun instead of the F-32 gun into the KV-1 tank at factory #92 by March 1st, 1941.
    A commission composed of representatives from ChTZ, the Kirov factory, GABTU, and GAU must perform trials and approve blueprints by March 5th, 1941. Factory #92 received a KV tank with a 76 mm F-32 gun on February 2nd, 1941.
  2. Install the 107 mm F-42 gun instead of the M-10 gun into the KV-2 tank by May 1st, 1941. Perform trials and work on blueprints, presenting them to the NKO no later than May 15th, 1941. Factory #92 received a KV tank with a large turret on January 29th.

Sunday, 18 June 2017

Praga LTL and Pzw 39: Tanks for Neutrals

In May of 1935, an Iranian commission signed a contract with CKD for light Praga TNH tanks. At the moment, these tanks did not exist in metal, but the Iranians saw the potential in this design. A prototype was demonstrated in September of that year. The Iranian commission was so impressed that the order was increased to 50 tanks on September 10th. For this time, this was a very respectable amount of tanks for the export market. It's not surprising that representatives from other nations came to Czechoslovakia to find inexpensive and high quality light tanks. CKD's engineers managed to satisfy their new customers, creating new tanks for Lithuania and Switzerland, known as the Praga LTL and Pzw 39.

Saturday, 17 June 2017

LT vz. 35: Steel Fist of the First Czechoslovakian Republic

On April 19th, 1933, the Czechoslovakian army signed a contract with CKD to produce 50 light P-II tanks. This ended the 10 year long quest to build a domestic tank. The tank accepted into service on July 13th, 1935, as the LT vz. 35 was sufficiently modern. However, a year later, the Czechoslovakian military needed a better protected tank. This tank, the LT vz. 35, was destined to become the backbone of the Czechoslovakian armoured forces.

Thursday, 15 June 2017

German Tank Fear

"Anti-Tank Defenses

14. The fear of massed enemy tank attacks still grips the soldiers, especially among the young and inexperienced replacements, to the point of mental breakdown. As a result, soldiers often leave anti-tank foxholes and positions, which lets enemy tanks cause significant losses and the Russian infantry to take our positions without battle.

Conclusions:

Training, among replacements as first priority, must harden young soldiers, especially infantrymen, against the mental effect of tank attacks. Every soldier must know that when he leaves his positions or foxhole, he becomes defenseless against tank fire, but a well prepared foxhole or, even better, a deep slit trench offer reliable protection against the weight and fire of tanks. It is necessary to take every opportunity to teach soldiers to let the tank pass above their trench using our tanks, assault guns, tractors, or captured tanks. It's necessary to prove the limited amount of visibility, and therefore precise fire, on the move from a tank. Every soldier must sit in a tank at least once."

Wednesday, 14 June 2017

PzIII Shortage

"June 20th, 1942
To the Deputy People's Commissar of Defense and GABTU Chief, Lieutenant-General of the Tank Forces, comrade Fedorenko
Moscow, 2nd NKO building

An experimental SPG on the chassis of a captured German StuG SPG, equipped with a 122 mm divisional howitzer mod. 1938 "M-30" was built according to orders from the Artillery Committee by factory #592.

Tuesday, 13 June 2017

Ultra Gun

The Department of Inventions was flooded with a great deal of proposals from the population, most of which received an answer similar to this one. However, a small fraction of the inventions were actually useful. Even if they were never implemented in metal, the USSR recognized the contributions of its citizens.

"To the Chief of the Central Planning Department of Inventions of the SNK

RE: Decision regarding the issue of a patent for claim #1582s

Having inspected the description, drawings, and all documents related to the request of citizen S.D. Bogoslovskiy, registered at the NKV under #1582s on April 23rd, 1942, under the title "Bicaliber barrel and shell, specially designed for an anti-tank gun", the Inventions Section of the Technical Council of the NKV decided to issue a patent for a gun barrel that fires "Ultra" shells with the following description:

Monday, 12 June 2017

What's in a Name?

There are a few examples where the real name of a tank or gun sinks into the sands of time, replaced by a more popular, yet incorrect one. The Renault FT is another example. More often than not, you see the tank called "FT-17", rarely "FT-18". Looking at production codes at Renault, the number was never included. For example, the Renault FT was preceded by the Renault FS, a car, and succeeded by the Renault FU, a heavy truck. However, even serious sources attach a number to the tank's name. Where did the number come from?

German documents regarding the Renault FT use the extra numbers.

Sunday, 11 June 2017

Renault D2: De Gaulle's Workhorse

The heavy Char B1 tank became the symbol of French pre-war tank building, and General de Gaulle is frequently associated with it. The 36 ton tank might have been the best French tank was indeed the best tank that France had during the fighting of May-June of 1940. The tank's thick armour worked well, even though the concept of the tank was obsolete.

Interestingly enough, mass production of the Char B1 might never have happened, since the French military was considering a different tank for the role of their main tank in the early 1930s, with the same armament, same armour, but more than 1.5 times lighter. This was the Renault D2, the tank that Colonel De Gaulle served in.

Saturday, 10 June 2017

Renault D1: FT on Steroids

Attempts to modernize the Renault FT, the most numerous tank in WWI, gave unexpected results. Initially, only the low speed was unsatisfactory for the French military, but its tastes grew by the mid-1920s. Now, the thin armour, which was insufficient to protect the tank from high caliber machineguns, was also unsatisfactory. The result was the NC-1 tank, which was 2 tons heavier and had thicker armour, while being twice as fast. The tank was a good replacement for the Renault FT, but the army's appetites grew once more, which led to the creation of a new tank, the Renault D1.

Thursday, 8 June 2017

KV-1 Engine Compartment

Details of the famous Aberdeen test are still not fully available online, all we have are scraps and rumours. However, user Makarov from Tiger's Corner shared a little bit of it with us. These high resolution photos of the engine and transmission compartments are sure to delight any dedicated scale modeler.

Fans of the "JS" vs "IS" debate will also both certainly be shocked at the new name the tank received in this report: KB.

Wednesday, 7 June 2017

Tukhachevsky on Tanks

A man like Mikhail Tukhachevsky needs no introduction, as he is one of the most famous military minds of the 20th century, having come up with the very effective Deep Battle doctrine. However, some of his ideas were rather odd, even for their time.

"In my note on tanks, I wrote: "If we take Magdesiev's calculations as 50%, then with our plans for tractor production in 1932/33 of 197,000 units, the annual tank production can be 100,000. If we consider one year of war to consume 100% of tanks (this is an arbitrary number), then we can maintain a park of 50,000 tanks."

Tuesday, 6 June 2017

Cromwells in Normandy

"Remarks regarding the use of Cromwell tanks in Normandy

1. Exhaust fumes, exhaust system, sparkplug fouling

A. The tank's users discovered that the exhaust fumes of the tank gave away the tank's position in moist weather. 

In order to immediately prevent this from happening, a protective cap for the exhaust pipe was designed. It is easy to install and it's made from scrap metal and refuse. The latter is used as stuffing.
This cap has the following advantages: