Saturday, 16 December 2017

Matilda's New Sword

On October 11th, 1941, the PQ-1 convoy arrived in Arkhangelsk: the first British convoy that delivered weapons and military vehicles to the USSR. It was the result of the agreement titled "On joint action of the Soviet and British governments in the war against Germany", signed in Moscow on July 12th. Matilda III tanks were among the cargo. In total, 1084 Matilda tanks were sent to the USSR, of which 933 (918 according to Soviet data) arrived.


Cannon famine

The delivery of tanks through the northern route was more akin to a stream than a torrent. According to archive documents, only 49 Matilda III tanks arrived in November-December. In this time, most tanks were sent to the 136th Tank Battalion (20 vehicles) and 132nd Independent Tank Battalion (12). In Soviet documents, they were called MK-II, MK-2, or Matilda.

The British tank was very peculiar. With a mass of a medium tank, its armour was comparable to the KV-1. A pair of Leyland diesel engines severely limited the Matilda's speed, but it was enough to accompany infantry.

Of the 49 tanks that arrived, the engines of 6 were ruined by frost. This was caused by water being used as coolant, which froze on the way. Many Matildas had frost damage to their batteries, as the density of the electrolyte was low.

The Matilda III with an F-96 76 mm gun, maximum gun depression.

There were other problems. Often, the receivers complained that tanks do not arrive fully equipped. However, some tanks came with a double set of parts and instruments. Tow cables were absent, more than a third of the tanks had no tarps. Radiators ruptured from the cold, which resulted in a complaint from GABTU chief Lieutenant-General Ya.N. Fedorenko directly to Mikoyan.

Poor knowledge of the tank led to additional damage. The front of the tank was wedge shaped, with the skirts attached to it, which covered up additional toolboxes. Not knowing this, technicians towed the tanks by looping the cables around the skirt armour, tearing it off.

The gun depression was only 2 degrees.

Tanks that arrived with convoys were first sent to Gorkiy (modern day Nizhniy Novgorod), where a foreign armour reception center was organized. Damaged tanks were the biggest headache of the center's specialists. By the start of December, out of 137 of the Matilda and Valentine tanks received in Gorkiy 58 were nonfunctional. Employees of the Gorkiy Training Auto-Armour Center (ABT Center) were forced to repair them with imported components, which were in deficit. Batteries were the biggest bottleneck.

ABT Center staff encountered another issue. The Matilda had a compressor for the gearbox control rods, which worked poorly in the cold. The "experience" in tearing off the skirt armour repeated itself here. In addition, it turned out that the smooth track surface of the Matildas resulted in them slipping around on ice. At the front lines this drawback resulted in instances where the tanks flipped over into ditches.

Another issue was the skirt armour, which covered up the suspension. They frequently became clogged with snow and mud, and paralyzed the tank when it froze.

The same tank from the front.

The tank's biggest issue was its armament. The 2-pounder (40 mm) gun had no HE shell. British doctrine, adopted in the 1920s with the Medium Tank Mk.I, dictated that the gun was only designed to engage enemy tanks.

Soviet specialists decided that the British were withholding AP-HE shells from the USSR. In reality, there was no such thing. The issue was further compounded by the fact that no spare barrels were shipped. If a Matilda's gun became damaged, it turned into a tankette.

This chance was high anyway, since no more than 5-6 loads of ammunition came with every tank. Considering the heated battles of the fall and winter of 1941, this kind of stock would not last for long. The situation demanded a solution, and fast.

With the KV-1's gun

The precise date when the proposal to re-arm the Matilda was made is unknown. It is likely that it happened in mid-November, when the analogous problem with the Valentine was being worked out. 

The initiator of the Valentine rearmament project was the head of the artillery faculty at the Military Academy of Mechanization and Motorization (VAMM), Military Engineer 1st Class N.S. Ogurtsov. He turned to the head of factory #92's design bureau, V.G. Grabin, who in turn gave the order to his senior design engineer, P.F. Muravyev. A project to install a 45 mm gun into the Valentine II turret was quickly developed, and the tank entered trials on December 2nd.

The ZIS-5, which was renamed F-96 when installed into the Matilda.

With the Matilda, the situation was different. Even though the tank was armed with the same 2-pounder, Soviet specialists did not wish to install a 45 mm gun. The mass of the Matilda was akin to that of medium tanks, and its armour was close to heavies. The three man turret allowed for the installation of a larger gun.

Factory #92 had such a gun. This was the 76 mm ZIS-5 tank gun, which was a modification of the F-34. The 1370 mm wide turret ring on the Matilda allowed for such a replacement. It is not known when work to install the gun began, but since the Matilda entered trials on the same day as the Valentine, it is likely that work went on in parallel.

The same gun from the right.

A Matilda III tank with WD number 10157 was chosen for trials. The cannon and BESA machinegun were removed, as was the gun mantlet along with the frame and its armour, ammunition racks, the Bren gun and its mount, the commander's seat, radio, and some other components. The cannon, BESA, and ammunition would be used to repair other Matilda tanks, and the Bren would be sent to the infantry.

Converted ZIS-5 frame.

The 76 mm ZIS-5 gun was installed instead of the stock gun. The frame had to be altered to fit into the tank. A gun mantlet from the experimental ZIS-5 was used. A special liner was installed between the turret and frame armour. It was built from high carbon steel on the prototype, but would be made of armour steel on production vehicles.

The coaxial machinegun was the Soviet DT, which rid the tank of dependence on British shipments. The gun travel lock was also altered. The trigger pedal was removed temporarily, but the plan was to return it on production vehicles.

The gunner's seat was replaced with one borrowed from the T-34. The carrier had to be designed anew. The turret platform struts had to be made anew. The elevation mechanism was taken from the ZIS-5. The turret traverse mechanism was pulled back. The exhaust fan in the turret roof was moved up by 50 mm, and its armoured cover was changed.

The ammunition racks were completely changed. A horizontal rack of 28 rounds (4 crates of 7 rounds each) was installed. There was also a vertical rack on the side for 6 rounds, and a rack on the floor (4 crates of 5 rounds each). In total, the Matilda carried 54 rounds. This was less than the T-34's 77, but still not bad. To compare, the stock Matilda carried 69 2-pounder shells.

Frame armour.

A State Committee of Defense (GKO) decree ordering the trials of the re-armed Matilda was given on December 1st. Trials continued between December 2nd and 11th. Their aim was to study the rearmed tank to ensure adherence to requirements and check crew conditions.

It turned out that the effort required to turn the elevation mechanism was no more than 6 kg, which was within normal range. The turret traverse required an effort of no more than 5 kg on even ground, but it increased to 30 kg when the tank was tilted by 6 degrees. However, this issue was not unique to the Matilda, and was also present on the T-34. The two options were either get used to it or place a 1000 kg counterweight on the rear of the turret.

A bigger problem was that the cooling grilles on the top of the engine compartment got in the way when the gun was traversed. To solve this issue, 4 of the grilles would be tripped, and the gun mantlet would be shortened from the bottom by 50 mm.

No defects arose during the trials.

The gun mantlet was taken from the experimental ZIS-5 gun.

The following conclusions were given regarding the trials:
  1. After a comparison of foreign and domestic weapons, inspection of the new mount, and driving and gunnery trials, we conclude that rearming the M-IIA tank with the 76.2 mm ZIS-5 gun and 7.62 mm DT machinegun is a reasonable measure.
  2. It is necessary to make changes to the turret as outlined in section V.
  3. We consider it reasonable to organize production of new turret parts and alteration of old ones at the Krasnoye Sormovo factory #112.
  4. Newly produced and altered parts should be sent along with the tank to workshops that possess the necessary lifting equipment and welding tools.
A discarded idea

The rearmed Matilda was delivered to Moscow in early January of 1942, where it was inspected by government officials. The proposal to produce 120 guns was explored. The gun was called F-96 in correspondence. Alas, the idea had a serious opponent in the face of Fedorenko himself. On January 9th, 1942, he sent a letter to Beria, who was in charge of armament, among other things.

"Comrade Grabin, Major-General of the Technical Forces and chief designer of factory #92 installed domestic armament into 2 British tanks: Matilda and Valentine. The Valentine tank has a 45 mm tank gun and DT machinegun in place of the 40 mm gun and 7.92 mm machinegun. The prototypes underwent trials at factory #92 in Gorkiy and were displayed in Moscow.

Based on my personal inspection and review of trials documents, I consider the rearmament of British tanks senseless for several reasons: 

  1. Valentine tank: The 45 mm gun has almost identical penetration to the English 40 mm gun, therefore it is sensible to use English armament for this tank and save our guns for domestic tanks.
  2. Matilda tank: The installation of the 76 mm gun is unsatisfactory. The turret is cramped and uncomfortable. Significant changes have to be made to install the 76 mm gun, and therefore it is also reasonable to leave the existing armament alone.

Currently, English tanks are sufficiently supplied with ammunition. In case of an insufficient amount of shells, it would be more correct to produce them ourselves, rather than install our guns in English tanks, especially since the 40 mm shell is a simple AP-T shell."

The experimental gun mantlet had a removable front.

Fedorenko was telling the truth about ammunition supplies. In late November of 1941, a torrent of correspondence erupted between the GABTU and the British military mission in the USSR. On December 5th, Mason-MacFarlane and Fedorenko met personally in Moscow.

The negotiations managed to solve most problems with shipments of British tanks. For starters, the British started filling the cooling system with ethylene glycol. Warnings written in Russian on the side of the tanks instructed technicians not to drink it. More cold resistant types of lubricant were used, which improved the tank's performance in the winter. 

The amount of shells shipped with each tank increased to 671, or almost 10 loads of ammunition. Finally, alongside regular tanks armed with 2-pounder guns, Matilda III CS tanks with 3" (76 mm) howitzers arrived. These tanks had no armour piercing shells, but had HE and smoke ones. The first batch of Matilda III CS tanks arrived on December 20th, 1941, with the PQ-6 convoy. This convoy also delivered Matilda IV tanks, the most numerous Matilda modification in the Red Army. In total, 915 tanks were sent to the USSR (and 156 Matilda IV CS).

A special liner between the turret and frame armour.

However, the real reasons for cancelling the re-armament project should be looked for elsewhere. Firstly, the initiator of the work was the GAU (Main Artillery Directorate), and not the GABTU. The complicated relationship between the two organizations left its mark on the process.

In addition, Fedorenko was not thrilled that factory #112 was tasked with producing guns for the British tanks. The factory just started T-34 production with great difficulty, and managed to surpass 100 tanks shipped per month only in December. There were still manufacturing issues. Loading factory #112 with something else at such a critical moment would reduce T-34 shipments.

The stock elevation mechanism was replaced with the corresponding part from the ZIS-5.

Despite all the objective issues, the cancellation of the rearmament was a mistake. By the spring of 1942, the 2-pounder gun was useless against German tanks. It could only successfully fight light tanks, and new medium tanks with 50 mm of armour were too much for it. The weak armament was one of the reasons why the British ceased production of the Matilda.

The installation of the F-96 gun could have radically increased the firepower of the tank, and given it an HE shell. Complains about its absence accompanied the Matilda for its entire service life.

The opportunity to task a factory with production of kits for re-armament was there in the summer of 1942, and ZIS-5 guns were available at other factories aside from #92. Alas, by that time, the idea was dead and buried. The British themselves were unable to increase the firepower of their tank. An attempt to install a 6-pounder (57 mm) gun was unsuccessful.

3 comments:

  1. I wonder what happened to the Bren Gun from the test vehicle - did it get sent to the infantry as planned?

    ReplyDelete
  2. Do you by chance have a side view picture of the F-34/ZIS-5/F-96 gun?

    ReplyDelete