Wednesday, 22 March 2017


"Mounting of a 57 mm mod. 1943 gun on a SU-76M SPG

This project is being designed according to an order from the Artillery Committee and consists of the installation of a 57 mm mod. 1943 ZIS-2 anti-tank gun barrel on the mount from the 76 mm mod. 1942 ZIS-3 gun on the SU-76M SPG chassis.

The ZIS-2 and ZIS-3 have identical semi-automatic systems and breeches.

The main characteristics of the prototype are shown in the table next to those of the SU-76M:

Tuesday, 21 March 2017

Light Tanks, 1944, Part 2

"To the Chief Engineer of factory #174, comrade Demyanovich
January 26th, 1944

Regarding your inquiry relating to tactical-technical requirements for a light tank, here are the possible changes to requirements:

Monday, 20 March 2017

Light Tanks, 1944, Part 1

"To the Chief of the GBTU Tank Directorate, Major-General comrade Afonin
January 5th, 1944

The preliminary tactical-technical requirements for a light tank that you sent were examined by a small circle of design and technology managers. Having studied your requirements in detail, we came to the following conclusions:
  1. In general, the requirements are realistic and such a tank can be designed and built at our factory.
  2. A number of issues you presented require special investigation and only then can they be implemented in a production vehicle.
Based on the above, we ask you to consider the following wishes of the factory when composing the revised tactical-technical requirements.

Saturday, 18 March 2017

Light Tank M3A1: Basket into Battle

History knows many instances when an attempt to improve a design led to, if not a worse one, then at least an equivalent. The American M3A1 light tank is one such example. Even though its modernization improved some characteristics, the well-intentioned modifications had some unintended consequences. Let us go through them in order.

Friday, 17 March 2017

Sweden's Autoloaders

Sweden's tank industry was in crisis in the second half of the 1940s. On one hand, the middle of this decade was a time when Swedish self propelled artillery thrived. That is when the Swedish army finally received assault guns, tank destroyers, and SPAAGs. However, the tank program lagged behind. Sweden's luck ran out with the Strv m/42. Pricken, LS 46, Leo, all of these projects remained on paper. Attempts to build a new tank weighing between 25 and 30 tons encountered various problems. A way out of this dead end appeared in the early 1950s, which led to two interesting heavy tank projects: the EMIL and the KRV.

Turtle Tank

Continuing the theme of sketchy intel on the Soviets the CIA got from the Germans, a phantom tank appears on the Volkhov Front, completely unknown to the Soviets, but apparently common enough in German eyes to even earn a nickname.

Wednesday, 15 March 2017


"Installation of a 203 mm mod. 1931 howitzer (B-4) on a KV-1S chassis (factory index S-51)

Produced by NKV TsAKB by order of the GAU Artkom.

The self propelled S-51 howitzer consists of the oscillating part of the 203 mm mod. 1931 howitzer (B-4) installed on a KV-1S. The installation is done in the following way:

The turret and turret ring are removed from the KV-1S. Instead of the turret, a plate is installed above the driver's head and the 203 mm mod. 1931 howitzer (B-4) is installed on it.

The fighting compartment remains free and is used to house the recoiling parts of the howitzer at high gun elevations.

Tuesday, 14 March 2017

Under Pressure, Part 2

In Part 1, we saw what happens to a tank crew when it's hit with a HEAT shell, whether that shell penetrates or not. However, getting hit with a kinetic penetrator has consequences too! Let's take a look.

"To compare, a table of measurements inside armoured compartments on impact from armour piercing and high explosive 76, 85, 100, and 122 mm shells with sensors positioned 200-1000 mm from armour, under the condition that the armour integrity was not compromised."

Monday, 13 March 2017

Under Pressure

HEAT is a much more complicated armour penetration mechanism than traditional kinetic penetrators, and thus leads to more interesting experiments. For example, in this one, the objective of the test was to determine how effective ERA was at disabling the heat blast, but more importantly, what an ERA block detonation would do to the crew.

The trials were performed on a model simulating a tank with ERA. Rabbits inside the model simulated crew.

Fig. 29. Overall view of model #2 with a U-5TS gun barrel installed.

Friday, 10 March 2017

CKD Export Tanks: An Offer You Can't Refuse

Czechoslovakian tank manufacturing caught up to world standards in the mid-1930s. The P-II, CKD's first light tank and the first mass produced domestically designed tank, was close to the world's leading designs. The LT vz. 35 that won the tender for a new cavalry tank caught up with the rest of the world's leaders. It's not surprising that Czechoslovakian tanks were considered for purchase in countries without a domestic tank design program. This caused the design of the CKD TNH and LTP (Tanque 39); excellent tanks that became the backbone of the Iranian and Peruvian tank fleets.

Thursday, 9 March 2017

SU-85 Light

"Installation of an 85 mm D-5 gun in a light SPG

The Gorky Automotive Factory is building an experimental 85 mm SPG using T-70 tank and SU-76M SPG components

Tactical technical characteristics of the prototype:
  1. Mass: 12,000 kg
  2. Full length with the barrel: 5500 mm
  3. Bore axis height: 1670 mm
  4. Maximum speed: 35 kph
  5. Muzzle velocity: 782 m/s
  6. Armour piercing shell mass: 9.2 kg
  7. Vertical range: -5° to +15°
  8. Horizontal range: +/- 12°
  9. Sights:
    1. Mechanical with Hertz panorama: 1
    2. TSh-15 telescopic: 1
  10. Ammunition capacity: 40 shells
  11. GAZ-203F engines: 2
  12. Total engine power: 170 hp"

Wednesday, 8 March 2017

D-10 CIA Intel

The following are penetration and ballistics tables for the D-10 gun mounted in a T-54 tank recovered by the CIA from a Soviet manual.