Tuesday, 21 November 2017

M10 Additional Armour

Major Berg, who you might remember from the Hellcat article, worked on the GMC M10 as well. The applique armour, the mounts for which are a distinguishing mark of this vehicle, were his idea.


Due to the difference in weight between the Sherman and the M10, 14 mm thick applique armour could be attached to the hull and turret without harming the performance of the vehicle. The total weight of the armour was 2031 lbs. However, the additional armour would only be mounted on a small percentage of vehicles serving in a special role, with the armour removed when the vehicle returned to its normal role.

Additional protection of this type was also considered for the M7.

Three types of this shielding (right against the armour, 1 inch, and 10 inches away) were tested at Aberdeen against M74 37 mm AP and M62 3 inch APC. The protection against the 37 mm shell did not differ depending on the distance, but protection against the 3 inch shell was better then the extra plate was right up against the armour. Interestingly enough, the protection with spaced armour was not any worse than a piece of armour of equivalent thickness.

Monday, 20 November 2017

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.

Saturday, 18 November 2017

Devourer of Tungsten

In late summer of 1942, the Red Army captured a German weapon that piqued the interest of the Red Army Main Artillery Directorate. This was the new German tapered bore 7.5 cm Pak 41. Several shells were captured along with the gun, which allowed trials to be performed and several characteristics to be determined. What was this gun, and what were the results of its trials in the USSR?

Friday, 17 November 2017

Frenchman in German Hands

The belligerents in WWII had to improvise time and time again. Obsolete weapons, no longer suitable for their initial purpose, found surprising new applications. One of the most notable examples of such a "second life" is the German conversion of the French 75 mm Mle. 1897 field gun, as a result of which the 19th century weapon became an effective anti-tank gun.

Thursday, 16 November 2017

Molotov Cocktails

If you ask people that know next to nothing of history, they will tell you that Molotov Cocktails are a Russian invention. People that know a little bit more will tell you that they are a Finnish invention. Keep going further, and you will be told that the original use of petrol bombs dates back to the Spanish Civil War.

Turns out, the first group was correct. However, these bombs came around long before Molotov accomplished anything of value, and didn't even have a proper name. In late May of 1915, Stavka's General on Duty wrote to the head of the Chief Military-Technical Directorate:

"The High Command Headquarters received several proposals for measures of repressing the enemy in response to their use of poisonous gases. These measures consist of burning the crops that are currently growing in Germany and Austria. In order to achieve this, we require widespread manufacture of incendiary devices of various weights..."

Wednesday, 15 November 2017

How Myths Are Born

I already discussed how, due to a mistake, the Light Tank M2A4 was "spotted" in the ranks of the Red Army. Since serial numbers were present in the listing, it was fairly easy to figure out that these were actually fairly common Light Tanks M3. 

Let's take a look at a similar situation. Once in a while, you can see rumours of the Medium Tank M2 being supplied via Lend Lease. It's not hard to be confused when you see something like this:


In this document the 201st Tank Brigade is complaining about all of the equipment that it's lacking. There is a shortage of every kind of staff, no artillery, hardly any machineguns, only one APC, and no heavy or light tanks. Instead of 20 T-34s, they received 22 "M-2" tanks. Makes sense, one medium tank replaces another, case closed.

Tuesday, 14 November 2017

Canadian Super-Tank

Most of my readers have probably heard of the Super Heavy Tank T28, a four-tracked 86 ton assault SPG that the Americans designed to bust through the defenses of the Siegfried Line. Interestingly enough, across the Atlantic Ocean, the British had a similar idea, but cranked up to 11.


Considering that the 80 ton T28 only managed a top speed of 8 mph, even 5-6 mph would be an optimistic estimate for this 150 (at best) monster. Thankfully, Gatehouse was right about one thing: experienced officers know what they're talking about, and Barnes managed to talk him out of the idea.


Monday, 13 November 2017

Lend-Lease Deficiencies and Spares

It's no small secret that a great number of vehicles ordered by the USSR through the Lend Lease program. Most of the issues with missing gear were solved very quickly, or so I thought. This table shows that missing weapons continued to be an issue until the end of the war. The number listed in the numerator is for weapons that were supposed to arrive, the number listed in the denominator is for weapons that actually arrived, split up by year. The second last column shows the total number of the weapon that was ordered and that arrived. The last column sums up the difference.

Sunday, 12 November 2017

Adventures of the Centurion in Scandinavia

Despite Sweden's goals to arm itself with domestic designs, foreign tanks in the Swedish army were not a rare sight. In cases when their industry was too slow or designers put out unsatisfactory results, the Swedish military made up the shortfall with foreign purchases. Recall that the Strv m/37, Sweden's most numerous tank at the start of WWII, was actually the CKD AH-IV-Sv tankette. Later, the Swedes acquired the Strv m/41, a licensed copy of another Czechoslovak vehicle, the LT vz. 38. A similar story happened again after WWII. Tired of waiting while domestic designers, the military purchased British Centurion tanks, which ended up being the most numerous tanks with a classical layout in the Swedish post-war army.

Saturday, 11 November 2017

The Swedish Army's Tough Choice

The time between the World Wars was that of rapid technical progress. Even tanks, a relatively new invention, could become obsolete quickly. Even though only several wealthy countries could afford a large number of the newest tanks for their armies, experimental vehicles and small batches cropped up in many nations. Sweden, who managed to retain neutrality during WWI, was among them. Its army was engaged in a lengthy and difficult search for a suitable tank. The search ended with the acceptance of the Strv m/31, or L-10, which begat a whole family of armoured vehicles.

Friday, 10 November 2017

Taubin's Automatic Grenade Launcher

In the mid 1930s, an automatic grenade launcher made by engineer Taubin was tested in the USSR. There were some good things about it, like a satisfactory shrapnel radius for grenades and a high rate of fire: 436 RPM! However, there were also many problems. It jammed a lot (7.2% of the shots), and the extractor had to be replaced 30 times over 587 shots. The precision, especially on the horizontal axis, was unsatisfactory.

Wednesday, 8 November 2017

U-20 Requirements

"Tactical-technical characteristics for the development of an experimental prototype of the oscillating part of the 85 mm AA gun on a T-34 tank chassis to create a self propelled anti-tank gun

November 7th, 1941
  1. The oscillating part of the 85 mm mod. 1939 AA gun will be installed on a T-34 tank chassis (with engine) without changes.
  2. The gun mount must meet the following requirements:
    1. Horizontal arc: 360 degrees
    2. Vertical range: from -8 to +30 degrees
    3. Aiming speed from one turn of the flywheel:
      1. Vertical: 1.2 degrees
      2. Horizontal: 3 and 7 degrees

Tuesday, 7 November 2017

Light SPGs

"Decision of the meeting held by the Deputy People's Commissar of Defense, Marshall of the Soviet Union, comrade Kulik
May 23rd, 1941

1. It is necessary to have four kinds of SPGs:
  1. SPAAGs
  2. Assault guns
  3. Tank destroyers
  4. Bunker busters

Monday, 6 November 2017

17-pounder vs. 17-pounder

The CACRU (Canadian Armoured Corps Reinforcement Unit) ordered a few 17-pounders for training. A 17-pounder is a 17-pounder, right? Well, it turns out, not so much.

Saturday, 4 November 2017

British Tank for Soviet Infantry

On September 29th, 1941, the first regular Arctic convoy departed from Britain to the USSR. It was indexed PQ-1. On October 11th, 11 transport ships arrived at Arkhangelsk, where they delivered 193 Hawker Hurricane fighters and other military cargo. Among it were 20 Matilda III and Valentine II tanks. So began the delivery of the Valentine tank, which became the most numerous British tank in the Red Army. 

Friday, 3 November 2017

Infantry Sweet Spot

The Valentine infantry tank was the most common British tank of WWII. Like the Matilda, it didn't last long as a front line tank in the British army, but commander versions and SPGs on the chassis made it to Germany. Its career in other countries was even more eventful. The Red Army used them until the end of the war, and they were widely used in the Pacific theater of war. In some nations, these tanks served as training tanks until the 1950s. What was the history of the creation of this extraordinary tank, and how did the first modifications of the Valentine serve?

Thursday, 2 November 2017

Foreign Aid

A lot of attention is aimed at the numbers for Lend-Lease aid received by the USSR in WWII, but what about the aid received by the Russian Empire during WWI? Despite being a much less discussed topic, the numbers are, in some cases, much greater than the LL ones. RGAE-413-12-8605 has the info we need.


Item
Unit
Import to Russia
 1914-1917
Import to the USSR
 1941-1944

  1. Aircraft (various)
units
11,000
15,641

  1. Aircraft motors
units
17,000
7,159


  • 76 mm cannons
  • Cannons of all calibers
units
5,625
-
-
10,654

  1. Bomb launchers and mortars
units
1,352
283


  • Machineguns (various)
  • AA machineguns
units

mounts
42,398
-
-
2,601


  • Rifles (various)
  • Submachineguns (various) and AT rifles
units
units
2,461,000
-
41,150
126,300

  1. Shells (various)
millions
15.7
49.9

  1. Cartridges (various)
millions
983.0
1,388.1