Friday, 18 August 2017

An Aryan From Poland

The Red Army GABTU had a very vague idea about the armoured vehicles of its potential enemy at the start of World War II. The same could be said about the other members of what would become the Allies. For obvious reasons, there was very little available information about tanks made by Germany and its allies. Mainly, it could be obtained from encyclopedias, which were full of errors. The ability to properly study the foreign tanks was only possible after combat began. In this respect, the USSR was ahead of the rest of the world. The first trophies began arriving from Spain: a captured PzI Ausf. A and an Italian L3/35. In the summer of 1939, a Japanese Ha-Go tank was captured in the Far East. The list of trophies grew with the start of WWII. The German PzII Ausf. C was among them.

Finders keepers, losers weepers

Even though the PzII was absent from Soviet encyclopedias, the tank was discovered before WWII. It's worth mentioning the index that the USSR assigned to it, since it explains the legend that the PzII, allegedly, was used in Spain. Some sources even give the year that it started its combat career: 1938. The Germans themselves do not admit this. The lists of tanks sent to the Franquists do not include PzIIs.

The solution to this mystery lies in the indexes used by the USSR. In 1939, a "light tank type II" appeared in Soviet documents, which likely laid the foundation for this myth. The issue was that the "light tank type II" was none other than the PzI Ausf. B. This tank was shown on information cards published in October of 1939. The tank retained this name in some wartime reference books, even though it was also called "German T-1a tank". This confusion started the myth that the tank was used in Spain.

An illustration of what the Soviets called "German T-II tank".

In addition to the "light tank type II" or T-II, another tank was known before the war, the "light tank type IIa" or T-IIa. Its description points to either the PzII Ausf. a or Ausf. b. The mention of the suspension, composed of six small road wheels coupled into bogeys, makes it obvious.

It is not known when the Soviets learned of this tank, but it was clearly not a PzI Ausf. B. It's possible that information arrived from foreign intelligence, especially since the Germans did not hide these tanks and used them in various events.

PzII Ausf. C at the NIIBT proving grounds.

The Red Army first saw the PzII in the fall of 1939. The so called "Polish campaign" began on September 17th, 1939. By 2:00 am on September 19th, Soviet tanks entered Lvov. A week before then, a battle between the Polish army and German forces, which included Rudolph Veiel's 2nd Tank Division, broke out in the region. The division fought to the north-west of Lvov, clashing with the Polish forces for the city of Tomaszów Lubelski.

It was necessary to repair the vehicle before it could be studied.

As a result, the Polish lost 35 tanks in the area, including 7TP, Vickers Mk.E, and TKS tankettes. Some of these vehicles belonged to the 10th Motorized Cavalry Brigade, commanded by Stanisław Maczek. A large part of the brigade managed to slip away towards the Polish-Hungarian border. The Germans took their share of casualties, and the disabled vehicle dump near Tomaszów Lubelski contained German tanks, as well as Polish.

The same tank after restoration. The large cross on the front of the turret made an excellent target for Polish anti-tank guns.

Colonel P.S. Fotchenkov's 24th Light Tank Brigade, the unit that took Lvov, spent its first week there getting settled into its new base. It is possible that a Polish POW revealed the presence of a large amount of Polish armoured vehicles. At that point, the borders between Germany and the USSR weren't set in stone, which Soviet tankers took advantage of.

"On orders from the Military Council of the Ukrainian Front, a group of 152 men with the necessary amount of combat and transport vehicles was formed on October 6th to evacuate captured equipment from the Krasnobrod-Uzefow-Tomaszów area, which was already occupied by German units.

Working selflessly, the group retrieved a large amount of valuable equipment, including two German tanks, two German guns, 9 Polish tanks, 10 tanketted and up to 30 cannons, and returned without losses."

Since there were no German lights available, the tank was equipped with domestic lights.

This list could have contained a third German tank. According to A.V. Yegorov's memoirs, who served in the 24th Light Tank Brigade, Senior Lieutenant Tkachenko stole a PzIII tank, although the tank was quickly returned to its owners. Nevertheless, an identification poster with characteristics and weak spots was composed for the PzIII Ausf. D. This is the same vehicle that, allegedly, was captured by the Red Army in the fall of 1939. It did not go through any kind of rigorous testing, but minimal information was obtained nevertheless.

The situation with another vehicle, a PzII Ausf. C, was different. This was a tank that was stolen from the dump at Tomaszów Lubelski, and nobody was thinking of returning it. This prize was sent to the NIIBT proving grounds in Kubinka. The USSR also managed to retrieve a PzII Ausf. A.

A modern fighting machine

The captured tanks arrived at the proving grounds in 1940. In documents, the PzII Ausf. C was referred to as T-IIb. The tank did not arrive at the vehicle dump in Poland as a result of a mere breakdown. According to the inspection act, the vehicle suffered several shell impacts. A shell from a Polish anti-tank gun struck one of the hatches in the front of the hull and damaged the gearbox case. As a result, the tank was disabled, and the crew likely abandoned it. The leaf spring mounts for two of the road wheels were also heavily worn. This meant that the tank, produced in 1938, was heavily used.

The rest of the damage was caused by other factors. The immobilized and abandoned tank was likely shoved into a ditch, and passers-by began slowly stripping it for parts. This was a common occurrence. Many photographs of vehicles with similar damage, vandalized by German repairmen, exist. In particularly severe cases, all that was left of the tank was the turret and the hull, as well as large components and assemblies that could not be removed without a heavy crane. Meanwhile, the tank that was up on cinderblocks (all suspension elements were removed) was still recorded as temporarily unavailable. To be fair, most such victims eventually returned into service, but only after a trip to the factory. Because of this, it is very difficult to recreate a more or less correct record of German losses. 

The tank had almost no stowed equipment left.

The only heavy damage dealt to the "privatized" German tank was to the gearbox, which was relatively simple to replace. The tank received additional "damage" while it was in the ditch and at the dump. The Germans removed a part of the wiring and electrical equipment, the crew seats, the radio and antenna, the instrument panel, the ammunition rack, the coaxial machinegun, the tow hooks, spare parts, instruments, and tools.

The Germans even removed the antenna and its support.

With so many missing parts, it was impossible to conduct trials similar to those that the PzI Ausf. A was put through. The NIIBT proving grounds staff had to retrain from testers to repairmen. A working tank had to be built with the "mix and match" method. The PzII Ausf. A was used as a donor, supplying the gearbox, front hatch, and other components.

The PzII Ausf. C was taken apart completely. Descriptions and blueprints of various components of the tank were composed. The resulting technical description was, in places, even more detailed than the tank's original manual.

It was not possible to put together a complete German tank from the available parts. The lights, battery, some instruments, and tow hooks were taken from domestic vehicles. As a result, the tank could be restored to running order, but a lack of spare parts made a full set of trials impossible. The only thing that could be done was a brief 100 km run, in order to establish the technical characteristics of the T-IIb.

View of the engine compartment. It's hard to guess that the radio operator's hatch is located here.

No documentation on the tank could be obtained, so some specifics of the tank's design were not accounted for by Soviet specialists. This included a number of very unusual features, including the method by which the radio operator left the tank. Our specialists had no way of knowing that the hatch doubled as an engine access hatch. However, there is nothing strange about that, since few people would guess that one can exit the tank in such a convoluted way.

PzII Ausf. C armour diagram.

The Soviet specialists did not pay much attention to the engine, since it was already well known by the fall of 1940. Germany officially sold three Sd.Kfz.7 halftracks to the USSR, which also use Maybach HL 62 engines. The ZF SSG 46 gearbox was much more interesting. The testers commented on the high level of precision in its manufacture. One advantage was the use of buffed spiral gears, which made them wear down less and reduced noise during operation. The specialists also liked the use of a synchromesh and the layout of the control rods, which were quite short.

The ZF SSG 46 gearbox was impressively well made.

At the same time, extracting the gearbox from the tank was a difficult procedure, which required removing the turret and turret platform. The PzI and other German tanks had the same issue. That was the price for a front transmission.

The planetary turning mechanism, reliable and long lasting, also received praise. The brakes were not well liked by Soviet specialists, since they were hard to adjust. Overall, the conclusions regarding the transmission was that it was reliable, simple to use, and could be counted among the best types of mechanical transmissions.

Kinematic diagram of the PzII Ausf. C's transmission.

The suspension was also interesting for the testers. According to the NIIBT proving grounds specialists, it provided for a smooth ride and dampened oscillations quickly, despite its light weight. The leaf spring suspension was compact and light, as were the aluminium alloy road wheels. The track tension mechanism also earned praise. It was hard to produce, but simple and reliable to use.

However, leaf spring suspensions were yesterday's news for Soviet tank building. After a series of experiments, it was clear that the future was with torsion bad suspensions, which was used on the T-40 amphibious tank at the time the PzII was being tested.

Suspension diagram. The leaf spring suspension was praised, but Soviet light tanks were already using torsion bars.

The hull and turret had nothing surprising about them. Their design was a logical continuation of the PzI hull and turret, which was a partially correct conclusion. The driver's hatch was criticized, since it was uncomfortable to use. The testers correctly assumed that the crew would most likely all enter through the turret hatch.

The tactical-technical characteristics of the captured tank specified that the crew consisted of three men, but the description of the fighting compartment said that it only contained the commander. The problem was that all seats were removed from the tank, and it was impossible to say where the radio operator sat, especially since the radio and antenna were also missing from the tank.

Driver's observation devices. They were only partially retained due to the efforts of German repair crews.

The observation devices were much more interesting. On one hand, they differed little from those used on the PzI. At the same time, the PzII had modernized observation ports with thicker glass. The specialists also took note of the fact that the tank used the same binocular observation device as the PzIII. The device was missing (the Germans removed it, along with the bulletproof glass from the driver's observation slit), but the same type of device was used on the PzIII Ausf. G, which was purchased in Germany in 1940. The device was removed from the PzIII and installed on the light tank for testing. The observation was evaluated as satisfactory.

Turret diagram.

The following conclusions were made after studying the captured vehicle:

"The German T-2b tank (the name is temporary) mod. 1938 is a continued modernization of the IIa type tank. Comparing the two tanks shows that the suspension was modernized.
  1. The armament of the IIa and T-2b is identical, consisting of a normal caliber machinegun, a 20 mm autocannon, and a submachinegun.
    The armour of both vehicles is 6-15 mm, designed to resist only armour piercing bullets fired from normal caliber machineguns and rifles.
    The overall shape of the hull is good, and provides for a good layout of the tank's suspension.
    The following equipment of the tank deserves attention from domestic designers:
    1. Turret traverse mechanism.
    2. Gun elevation mechanism.
    3. Machinegun mount in the turret.
    4. Backup driver's observation device.
  2. The tank uses a mass produced Maybach automotive engine (the same kind is used on the Krauss-Maffei halftrack). The engine is a mature design and is reliable in function. In addition to an electric starter, the engine can be started with an inertial starter.
  3. IIa tanks use a suspension with six small road wheels per side, coupled into bogeys. The T-2b tank uses an independent suspension with five larger road wheels per side. The suspension is original, simple, and ensures a constant contact between the tracks and the wheels. The compactness and dampening qualities of this suspension had advantages over torsion bar suspensions. The track has small links, which hook into the drive sprocket pinwheel, preventing it from slipping off.
  4. The transmission of the T-2b is analogous to the T-2a, typical for German tank design. The presence of a six-speed gearbox provides the tank with good maneuverability and makes it easy to drive.
    The planetary turning mechanism is large, heavy, and complicated. An advantage is that it is reliable and does not need to be adjusted often.
  5. Components that need to be inspected and adjusted often are accessible. It is difficult to remove components (for example, the turret must be removed to take out the gearbox). The latter can be explained by the fact that the quality of produced tanks is high and the components do not break often.
    The T-2b is built according to a unified plan, like all tanks in Germany. The use of a unified plan and compatible, standardized parts makes production cheaper and faster, as well as allows for easier training of crews and technicians. The T-2b is a modern tank from a production and design standpoint."
Uninteresting

Despite the complimentary review, the PzII Ausf. C was not very interesting for Soviet tank designers. Soviet design took large steps forward in 1939-40. The Soviet analogue of the PzII was the SP-126 infantry support tank, which later transformed into the T-50. Even at early stages of development, the PzII was inferior in every way.

The medium German tank, the PzIII Ausf. G, was much more interesting, and had a noticeable effect on Soviet tank building. This also includes light tanks, since a decision was made to make characteristics of light tanks as close to those of medium tanks as possible.


Visibility diagram of the PzII Ausf. C.

The second tank, the PzII Ausf. A, was sent to Leningrad, to be studied at NII-48. There, the tank was included in a program to study foreign armour. Interestingly enough, this tank was recorded as "German-produced Polish tank, welded construction" in the documents. The tank was taken apart, and the hull and turret were later shot up. The report remarked that the hull parts were carefully made, and the welding seams had no cracks afterwards. The armour itself was considered brittle.

The restored PzII was to be left at the Kubinka museum as of April 1st, 1941. After the start of the Great Patriotic War, the tank's trail disappears.

A taken apart "German-produced Polish tank", a PzII Ausf. A, on trials at Leningrad.

Several PzII tanks ended up at Kubinka during the war. Afterwards, only one tank remained, a PzII Ausf. F, turret platform number 28384. It was most likely produced at the Ursus factory in Warsaw. It's worth mentioning that no studies of the PzII were performed in the USSR during the Great Patriotic War. The tank was yesterday's news by then.

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