Monday, 14 November 2022

HPZ’s Unlucky First

August 20th, 1920, can be considered the starting point for Soviet tank building. It progressed pretty quickly. By 1921, the Red Army already had classifications for its new tanks. Captured British Mark V tanks were assigned to category B, or breakthrough tanks. Mk.A Whippet and Mk.B Hornet tanks were assigned to category S, manoeuvre tanks. Finally French Renault FT tanks and the Russian Renault were assigned to category M, support tanks. For obvious reasons, development of category B tanks was not expected until the future. They were too heavy and complicated for the nascent Soviet industry. A decision was made to focus on manoeuvre and support tanks. Work was conducted by the GUVP (Main Directorate of Military Industry) headed by Senior Engineer Shukalov as of August 1921. Until 1924, this department largely stood idle, since no decision was reached on who would build these tanks and how. There were various ideas discussed, including letting factories design their own tanks. There was already one such instance, although the development of the Teplokhod AN at the Izhora factory was never completed.

Final iteration of the 16 ton manoeuvre tank developed by the GUVP. This was a predecessor of the T-12 tank.

A technical tank bureau was formed on May 6th, 1924. Essentially, the Technical Department of the GUVP was reorganised. Shukalov led the new bureau and V.I. Zaslavskiy became his deputy. Two projects were launched at the same time: a 3 ton regimental support tank that later grew into the T-18 (MS-1) and a 15.7 ton maneuer tank armed with a short 76 mm gun and 3 Fedorov machine guns. The 150 hp Ricardo engine would give it a top speed of 20 kph. The armour was just 13 mm thick. Further developments showed that these estimates were quite optimistic and the mass grew to 18 tons. The project went through several iterations, at the end of which it weighed 16 tons and had a 45 mm gun as main armament, a second machine gun turret in the back, and a completely reworked lowered hull with 22 mm thick armour. By this time it was clear that development hit a dead end. There was also a lot of new experience from the T-18 tank that was accepted into service with the Red Army on July 6th, 1927.

“Manoeuvre tank with a Hispano engine”, August 1928. This tank turned into the T-12.

As a result, a brand new manoeuvre tank was needed by the spring of 1928. Its creation was authorised by the Revolutionary Military Council on March 9th, 1928. A draft project was ready by August. This was a whole new tank that included the experience of working on the T-18. The mass was the same 16 tons as the last GUVP tank, the speed and armour were also the same. The rest of the tank was different and looked a lot more mature. One interesting feature of the tank later designated T-12 was the multi level armament. The machine gun turret was moved from the rear to the top of the main turret. Some researchers consider this a copy of the Medium Tank M1921, but there are no similarities here. The Christie M1919 is a much more similar vehicle, including the stacked turrets. The T-12 was a completely original tank and more successful than the M1921. Keep in mind that tank development followed a different system back then. Early stages of development were concentrated in Moscow, after which the project was transferred to the factory that would build it, and the local design bureau would put the finishing touches on the work with direction from Shukalov’s people. This is what happened with the T-18, which was built at the Bolshevik factory in Leningrad. The T-12 followed the same principle. The Kharkov Locomotive Factory (HPZ) was picked to build it. This was no accident, as it already built Kommunar tractors and had equipment suitable for producing heavier vehicles than the T-18.

The T-24 was first envisioned like this. Initially, the only difference was the armour that was reduced to 20 mm.

I.N. Alekseenko led the T-12 project at HPZ. The prototype was ready by December of 1929. The combat mass was higher than expected: 19.6 tons. Trials went poorly. The tank was pursued by various technical issues that are not uncommon for any experimental tank. Preparations to put the T-12 into production began anyway in the fall of 1929. HPZ would be tasked with final assembly. Parts for the tanks were built at other organisations, for instance the hull was the responsibility of the Izhora factory. The factory began discussing producing the first 10 sets of armour in October of 1929. Production of a 15 tank pilot batch was planned in total, after which a second later batch would follow, just like with the T-18. This never happened. Trials showed that the tank was too overloaded. The UMM (Directorate of Mechanisation and Motorisation, the first organisation outside of the artillery branch tasked with tank development) required that the mass of the tank be reduced in February of 1930. This could be done by lowering the armour thickness to 20 mm. The Izhora factory was alerted of the change in March and a reworked T-12 named T-24 appeared in April of 1930. It was more or less the same as the T-12, but with a combat weight of 18.5 tons. The 250 hp engine gave it a top speed of 22 kph. Like the T-12, the tank had its armour plates joined with rivets, but Izhora factory was instructed to make one welded hull. The T-18 was also supposed to we welded and a welded hull was even produced, but it was not put into mass production in time.

The T-24 looked like this at the end of development. The significantly different hull can be seen here, the turret also has plenty of changes.

Work on the T-24 fell behind schedule, since solutions that would migrate to the production tank were still being tested on the T-12. The UMM was planning mass production. For example, the Izhora factory was expected to build 350 hulls and turrets in 1931. Even after delivering the first batch of 15 hulls, the factory resisted, and so the same order for 10 hulls made in October of 1929 still stood. The UMM’s demands were stalled for various reasons every time. There were lots of complaints about the technical documentation developed by the GKB OAT (Main Design Bureau of the Arms Arsenal Trust, the name of Shukalov’s organisation at this point). There were good reasons for it. Many changes were made to the T-24 that noticeably changed its look. The hull changed thoroughly, in part panniers were added that held the fuel tanks. The driver’s station was changed and the turret sides were now curved, among many other changes. This was a very different tank instead of just a lighter T-12.

One of the few T-24s to receive proper armament.

The Central Committee of the VKP(b) made the final decision to produce the T-24 at HPZ on November 5th, 1930. Work was expedited after that, but it was doomed to fail. The Izhora factory was overloaded with orders and made no secret of the fact that it would not be able to produce more than 10 hulls a year. Only two were finished by the end of November. The HPZ also had its own problems. As a result, Kharkov could not complete the order for 15 or even 10 vehicles. The UMM did not get even a single tank in 1930. The urgency for the tank of this type could be inferred from the requirement to build 350 hulls. Delivery only began in October of 1931, by which point the tank’s fate was already sealed. Only 24 tanks were delivered, at best 5 of them received any armament. The 45 mm model 1930 gun died with the T-24. A different family of weapons that initially used the 37 mm caliber came to replace it.

Most T-24s never got their armament.

The decision to cancel T-24 production was made on May 23rd, 1931. On the same day, a decision was made by the Commission of Defence of the USSR to adopt the Christie tank into service as a high-speed tank destroyer. This tank, designated BT, would be produced at HPZ. Debate around whether or not this was a mistake is common. Some historians argue that it would have been possible to modernise the T-24, others claim that T-24 tanks with 30 mm of armour were delivered. Izhora factory can’t confirm these theories. Its documents state that T-24 hulls only used 8.5 and 20 mm thick plates. The theories about modernisation are interesting, but entirely unfounded. Most importantly, historians that compare the BT to the T-24 make one crucial mistake. The BT was the last proposed replacement for the T-24, far from the only one. The question wasn’t whether or not to keep the T-24, but what tank would come to replace it.

This tank remained at the VAMM as a teaching aid.

As many know, tanks were developed very rapidly in the late 20s and early 30s. Just because few were built doesn’t mean that development stood still. Requirements only increased, which often led to the death of promising projects. The T-18 was satisfactory for only a few years after production began. It was only built in such numbers because it appeared at the right time. The T-12/T-24 were simply poorly timed. Not only did the armour had to be cut down, but the mobility of the tank was below the requirements for the end of 1929. This is why Izhora factory received an order for 6 D-series tanks designed by N.I. Dyrenkov. This tank had a convertible drive and a top speed of up to 35 kph. The problem was that the design of the tank was terrible. The Izhora factory treated the tank coolly and the fate of the D-4 tank was not successful.

The T-24 was obsolete by 1931, so replacing it with the BT was quite logical. The BT was far from the only replacement for this tank.

The TG tank developed by German engineer Eduard Grotte was in a different boat. The tank had the same engine as the T-24, but a top speed of 35 kph and armour capable of withstanding cannon shells. The firepower was also incomparable. The UMM seriously considered putting the TG into production at HPZ. The problem was that the TG was quite unrefined and the M-6 engine was only used because Grotte couldn’t get his own engine working. Mass production of the TG never happened either, but that still meant that the T-24 was far from the tank that the UMM wanted by 1931. It was small, slow, and had no real room for modernisation. What kind of modernisation was possible if the armour had to be made thinner before the tank could go into production? The tank’s lack of future is also highlighted by the fact that even the British Medium Tank Mk.II was considered as a tank that could go into production at HPZ, although it was no better than the T-24 and more complicated to boot. The BT was the only option as the tank with the fewest problems, a ready to go engine, and very high mobility. There were no alternatives to the BT.

The Red Army didn’t get a good tank, but they did get a good tractor on its chassis. The Comintern was the best tractor in the world in its weight class when it entered production.

Even though the T-24 tank was a failure, the chassis came in handy. The Comintern tractor was developed from this tank at HPZ under the direction of B.N. Voronkov. After several iterations of refinement, this tractor was one of if not the best in the world. It became the Red Army’s main heavy artillery tractor and remained in production from 1934 to 1940 when it was replaced by the Voroshilovets. As of January 1st, 1941, the Red Army had 1581 tanks of this type. Many tractors were lost in the first year of the war, but as of May 1st, 1945, 614 units remained, 547 in running order.

Most T-24 tanks ended their days like this. There was not even enough time to dig them in as fortifications.

The subsequent fate of these tanks deserves attention. They did not enter service with combat units and were used only for training. The tanks were still kept in inventory by 1938. A decree was passed in April of 1938 sending these tanks and other obsolete vehicles to be converted into fortifications. Two tanks were sent to the NIBT Proving Grounds museum. One tank remained with VAMM (All-Union Academy of Mechanisation and Motorization) until the start of the war. The NIBT Proving Grounds never reported the receipt of a T-24. Some vehicles were converted into fortifications and captured by the Germans in this state. Most T-24 tanks were captured as is in one of the warehouses of the Kiev Special Military District. They did not even see use as fortifications.

Original article by Yuri Pasholok.

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