T-37 and T-38 Applique Armour

"To the Deputy People's Commissar of Tank Production, comrade Goreglyad
CC: factory #37 director

The question of adding applique armour to T-38 and T-37 tanks during their repair and turning them into land tanks has arisen.

I ask you to instruct factory #37 to develop blueprints for applique armour for the T-38 and T-37 with calculations of change in mass and other parameters.

GABTU BTU Chief, Military Engineer 1st Class, Korobkov
GABTU BTU Military Commissar, Regimental Commissar [illegible]"

Experimental Tank Guns in 1940, part 2

We saw some Soviet pre-war prospective guns in a previous article, let's take a look at the rest of the list.

Name	Mass	Oscillating part mass	Top speed (kph)	Practical rate of fire RPM	Horizontal range	Vertical range	Max. range (km)	Muzzle velocity m/s	Shell mass (kg)	Effect/ Notes
152 mm M-10 tank howitzer in the KV tank	53 tons	1890	Up to 20	1-2	360	-3 +12	6	436	51.07	Penetrates 90 mm of armour at 1000 m
122 mm corps gun for the KV tank	54 tons	3200	Up to 20	2-3	360	-3 +15	13	800	25.2	Penetrates 130 mm at 30 degrees at 1000 m (calculated)
85 mm SPG on T-34 chassis (tank destroyer)	26 tons	1200	Up to 40	15	360	-5 +45	17	800	9.2	Penetrates up to 88 mm at 30 degrees at 1000 m (calculated)
130 mm SPG (B-13) for the SMK	64 tons	-	Up to 20	2	6	+12	15	870	33.5	Penetrates 130 mm of armour and 40 mm of iron liner at 4400 m. Ready by September 1st, 1940.
152 mm SPG (Br-2) for the SMK	64 tons	4200	Up to 20	0.5	6	+12	13	860	51.07	Penetrates 130 mm of armour at 30 degrees at 5000 m and 150 mm of armour at 0 degrees at 1100 m. Ready by September 1st, 1940.
55-60 mm anti-tank gun	1000 kg	-	Up to 50	15	60	+25	13	At least 1000	Up to 3	Penetrates 70 mm of armour at 1000 m at 30 degrees (calculated)
76 mm anti-tank gun based on the USV or F-22	Up to 1800 kg	1200	Up to 50	15	55	+45	15	813	6.5	Penetrates 70 mm of armour at 30 degrees at 1000 m. Uses shells from the mod. 1931 AA gun. Ready by October 1st, 1940

The first entry is pretty self explanatory: this is the KV-2. By this time, 4 KV-2s have been assembled, but it has not gone into production quite yet, so it still shows up on the experimental list. The second entry is quite interesting: some kind of proto-IS-2. It's interesting to see such a powerful gun in a rotating turret so early in the war.

Next, we have something my readers should already be familiar with. The 85 mm gun on a T-34 chassis is the U-20 tank destroyer. 

Now here's something a little more obscure. Fans of Soviet tank history will know that the T-100, SMK, and KV faced off for the title of the Red Army's next heavy tank during the Winter War. By the summer of 1940, when this list was composed, the KV had already won. However, it seems that the SMK wasn't quite dead yet. Two SPGs, one with a 130 mm gun and one with a 152 mm gun, are still being pitched. The tank may have never moved forward, but the idea of SPGs with these guns remained. The 130 mm S-26, based on the B-13, was used in the ISU-130 SPG. The 152 mm Br-2 on a self propelled chassis was a long-lived dream of Soviet artillerymen, with several attempts, like the U-19, and S-51.

The 55-60 mm anti-tank gun is another familiar sight. This is, quite obviously, the ZIS-2. The 76 mm anti-tank gun, however, is more interesting. There were attempts to build guns for the KV (ZIS-5, first iteration) and T-34 (S-54) with the ballistics of this gun, so it's only logical that a towed version would also be made. This particular implementation looks similar to the Pak 36(r), with the existing F-22 being adapted for a more powerful round.

Pz.Kpfw.I Ausf. C: Kniepkamp's Latecomer

Putting the PzI Ausf. B into production was the correct decision, albeit a late one. The problem wasn't only that the concept of a light tank with machineguns for armament was obsolete. The 6th Department of the Armament Directorate was disappointed in the chassis developed by Krupp's engineers overall. Even though the power to weight ratio of the PzI grew from 11.1 to 17.2 hp/ton after modernization, there was no drastic improvement in mobility. 40 kph is not what was expected with such a boost. It's not surprising that, instead of developing the PzI Ausf. B further, the German military decided to develop a completely new tank: the PzI Ausf. C.

Pz.Kpfw.I Ausf. B: All Grown Up

The creation of the PzI light tank did not come easily for German tank building. The tank was redesigned several times while still in the development stage, starting out as a 3 ton tank with a 20 mm autocannon, and ending up as a 5 ton tank, where nothing larger than a pair of MG-13 machineguns could fit into the turret. Even though the PzI entered production and became a mass produced tank, easily numbering over 1000 units, the German tank forces were not completely satisfied with its characteristics even before production began. Modernization was only a matter of time. What results did it bring?

The Other M-30

"Technical data of the M-30 303 mm HE (chemical) rocket

Parameter	Tested variant	In production
Total weight	82 kg	76 kg
Mass of explosive (nitrol)	27 kg	21 kg
Mass of poison (Yperite)	24 kg	21 kg
Volume of explosive or poison chamber	18 L	16 L
Range	2550 m	3000 m

KV Tank Markings

"To the chief of the "Balance" operational department

In order to more easily control and identify fighting and transport vehicles, the Commander of the Army's Armoured Forces gave the following order:

1. For tank units, introduce the following identification marks:
1. 1st TC and 8th G.TBr: Rhombus
2. 26th TC: Circle
3. 4th TC: Square
   drawn on in white paint on the side and rear of the turret. The size of the marks is 50 cm, with a 5 cm thick outline.

Truck Amphibian

"Towing barges with a ZIS-5 truck

When crossing deep rivers, drivers of the Nth Front successfully used a ZIS-5 truck to tow a barge. Equipped with special wheels, the truck could easily tow 12 ton barges at a speed of 4 kph (see figure).

New Gun for the T-34

"On arming the T-34 with an 85 mm gun instead of the 76 mm F-34 gun

In order to improve the artillery armament of the T-34 tank, the State Committee of Defense decrees that:

1. The 85 mm tank gun designed by TsAKB (comrade Grabin) is accepted into service and named "85 mm tank gun model 1944 (S-53)".
2. T-34 tanks, starting with January of 1944, will be armed with the 85 mm tank gun model 1944 (S-53), installed with the stock turret ring, instead of the 76 mm F-34 gun.

Howitzer KV

So called artillery tanks, or support tanks, appeared in the mid-1920s. The British pioneered the concept, equipping their Medium Tanks Mk.I and Mk.II with 94 mm howitzers. Similar tanks were also built in other countries. The USSR was no exception. The first work on artillery tanks in the USSR began in the early 1930s. The BT-7 Artillery was the best known vehicle of this type. The KV-2 can also be placed into the artillery tank category, with some leeway. The artillery tank concept was rejected by the USSR before the start of WWII. Nevertheless, the KV-9 was designed in early 1942, a tank that fully fit into the category of support tanks.

Big Gun for a Small Turret

In June of 1940, the Red Army GABTU began working on modernizing the KV-1 heavy tank. Even though production had not yet fully began, the military already had issues with the tank. This is a fairly ordinary scenario, especially considering the fact that tank development sped up with the start of WWII. According to the GABTU, the KV-1 needed more armour and, more importantly, a more powerful gun. It's hard to argue with the latter, since the Red Army's heavy and medium tanks, KV-1 and T-34, ended up with the same gun.