Ever-Changing Tank Nomenclature

One of the topics that resurfaces in arguments about armoured vehicles is classification. It wouldn’t be so bad if people far from the science of armoured vehicles made mistakes, but quite notable historians also throw fuel on the fire. The T-28 is one of the most misunderstood vehicles. There is a certain group of people who draw modernisations onto the T-28 that would allegedly make it a suitable replacement for the T-34. After all, both have a 76 mm gun, similar weight, two tracks, basically the same thing! The fact that the T-34 was built to replace the BT doesn’t bother them, neither does the fact that it was the SMK that was first supposed to replace the T-28 and then the KV. The T-28 tank was included in heavy tank brigades. This seems like a very strange fact if one is not familiar with the Red Army’s system of classifications. Similar mistakes are made regarding tanks of other nations. For instance, the Panther is often called a heavy tank, but it’s enough to look at where these tanks went and what vehicles they replaced. Today we will cover the Soviet tank classifications, touching foreign vehicles a little for context. Keep in mind that the same names can mean different things in different times.

Classification of tanks in the Red Army. Bronevoye Delo magazine, March 1921.

A 16 ton maneuver tank designed by the GUVP. No one ever called this tank "medium".

A “large tank” or “category B” tank. This used to be the most common tank in the Red Army, but the low mobility and high mass led to no work on heavy tanks being done until the early 1930s. 

Tanks had no classifications at all at first. The situation changed when the French and then the British began to build medium tanks, then the French came out with the first mass produced light tank. The classical tank categories solidified by the start of the 1920s: light, medium, heavy. However, they weren’t called this at first. In the USSR, heavy tanks were called “large tanks” (category B), medium tanks were called “manoeuvre tanks” (category S), and light tanks were “small tanks” (category M). Tankettes arose as a class in the mid-20s, and they were called “Lilliputians”. It’s easy to see why medium tanks were called manoeuvre tanks. These were the most mobile tanks the Red Army had. This situation didn’t change by the second half of the 1920s. The manoeuvre tank was still faster than a light one by definition. The 16 ton GUVP Maneuver Tank had a top speed (at least on paper) of 20 kph. The first variant of the tank that would become the MS-1 had a top speed of 12, then 14 kph. There were no plans to build large tanks, since the Red Army brass clearly understood the industrial achievements necessary for such a vehicle. The Soviets didn’t want something like the A1E1 Independent. Judging by drafts made by consultants from Ansaldo in the late 1920s, this would have been a 65 ton tank similar to the FCM 2C.

The T-18 was called either a “small tank” or a “support tank”.

A similar situation arose in the summer of 1929 when V.K. Triandafilov, one of the main theorists of deep tank operations, reported on the Red Army’s armament system. There was no large tank yet. The small tank weighed 7-7.5 tons, had a speed of 25-30 kph, a crew of 3. It would be armed with a 37 mm gun and 2 machine guns. The fastest type would be a convertible drive tankette (clearly influenced by the Carden-Loyd Mk.V). The 3.3 ton vehicle would reach a speed of 40 kph on tracks and 60 kph on wheels. The designation “medium” first came up in association with the manevuver tank, but the designation didn’t change. The mass was estimated at the same 16 tons and the speed rose to 25-30 kph. The mobility remained at least on par with the small tank. A handful of SPGs were described to go with them. This system was quite modern, but Soviet industry couldn’t keep up with it. The only tank that more or less fit in was the T-12, which later turned into the T-24. HPZ failed to set up production and the vehicle gradually fell into obsolescence. This forced the UMM (Directorate of Mechanisation and Motorisation, a new organisation created in November of 1929) went abroad. The goal was to purchase samples of foreign vehicles. These samples began to arrive in the fall of 1930 and the first results of trials were obtained by early 1931. A time of wonders began in the classification system.

The Christie tank was a trial for the Soviet armament system. It didn’t fit into it formally and a whole new class had to be created for it: the fast tank, sometimes called the fast tank destroyer.

The situation with the small tanks and tankettes was the simplest. The British Carden-Loyd Mk.VI was a good match for the Red Army’s system, and after some improvements it was accepted into service as the T-27. The British Vickers Mk.E infantry tank also more or less fit in. The two turrets were an issue, but one of the turrets would have a 37 mm cannon, so it was close enough. Work on a two-man turret began in 1931 and it went into production in 1933. The medium (maneuver) tanks didn’t do as well. There were several factors contributing to this situation. One was the destroyer of tank classifications known as the Christie Tank. It didn’t fit into the Soviet system at all. It was too weak for a medium tank, but too large and heavy for a light one. The tank was also less of a tank and more of a DIY starter kit. There were two advantages here: the tank had high mobility and came with a full set of technical documentation. This was one of the reasons that led to production being set up at HPZ. The tank came with a new classification: “fast tank”. This designation later changed to “operational tank”. This was something of a semi-medium tank. HPZ met the new tank with mixed feelings. The factory’s design bureau proposed a modernisation by late 1931. The new tank had a two man turret, two man driver’s compartment, and a new running gear. Its mass was estimated at 12 tons. The project was declined. 

The TG-1 also delivered a blow against the Soviet tank system. Instead of the expected 18-19 tons it weighed 25. This tank was later developed into the T-35.

The Christie tank was not alone in creating a mess within the tank classification system. Another such tank appeared in 1930. The TG-1 was developed by German engineer Eduard Grotte. This was initially a typical manoeuvre tank weighing 18-19 tons with a top speed of 45 kph achieved by a 250 hp engine. A similar project called D-3/D-4 was developed under the direction of N.I. Dyrenkov, except by early 1931 it was clear that the development hit a dead end. In comparison, the TG-1 built by Bolshevik factory’s AVO-5 department with the participation of Soviet specialists (including N.V. Barykov) looked quite promising. This tank had powerful armament (37 and 76 mm cannons) and 30 mm thick armour. This armour is described as bulletproof today, but at the time this was enough to withstand anti-tank guns. 25 mm was considered sufficient as recently as the mid-20s. Grotte’s tank was so interesting that a decision was made to put it into production over the T-24 in November of 1930. Unfortunately, Grotte’s tank ballooned from 18-19 tons to 25, plus the trials gave mixed results. By the spring of 1931 it was clear that the tank was ridden with problems, and so the BT was put into production.

Another tank that was a medium tank in practice. Initially, the PT-1 was supposed to weigh 16 tons, but the real one was lighter. This tank was inspired by the Grosstraktor.

This wasn’t the end. Work on a new medium tank very similar to the T-24 began in the summer of 1931. This was the T-28 tank. Initially, it had a mass of 16-17 tons. In July of 1931, the Special Design Bureau (essentially a scientist prison) presented an 11 ton convertible drive tank project. This tank was notable because it was also amphibious. This wasn’t a grassroots proposal, since there was already a set of requirements for an amphibious tank based on another vehicle that as undergoing trials at the time: the Grosstraktor. The tank could swim, although badly, and it sank during trials. The Germans gave up on the idea, but the USSR didn’t. Modern historians group the “Soviet Grosstraktor” in with light tanks, but the PT-1 was creased as a medium tank. The designers also copied the idea of moving the commander to the front-right of the hull instead of the turret. The lead engineer on this project was N.A. Astrov. Construction of this project was approved. The TG-1 was also not abandoned completely. Grotte’s contract was terminated, but work continued. The project called “powerful tank” or “improved TG” was later renamed to T-35. The result was very different, but it was the end result of “inflating” the TG. Even the T-35 was called a medium tank at the beginning.

The T-28 was initially created as a typical manoeuvre tank weighing 16-17 tons. The Red Army requested more powerful armament in 1932. This resulted in a weight increase to 23.5 and then to 25 tons. The tank’s purpose also changed somewhat.

Soviet tank building entered 1932 in this strange shape. The tank system changed again. Tankettes disappeared, the concept of “super-light” tanks was introduced. These were inspired by Vickers-Carden-Loyd amphibious reconnaissance tanks. A Soviet analogue was created in 1932. The T-35 tank was upgraded to a heavy or breakthrough tank. Finally, requirements for a super-powerful tank were composed. It would weigh 75 tons, reach a speed of 30 kph with a 2000 hp engine, carry an armament of a 76 mm gun, two 45 mm guns, and machine guns. The project didn’t live for long as the requirements for armament increased drastically. The project was sent to Ansaldo, and another tank was designed based on their work: the T-39. In short, the USSR wanted a breakthrough tank like the FCM 2C. Work on the PT-1 was still going on in parallel. It was distanced from these metamorphoses, but there was not yet a place for it in the system of armaments. The 14 ton tank could have potentially been a replacement for the BT.

This is how Soviet medium tanks were classified in 1932. Yes, the T-35 was classified as a medium tank, but not for long. Note how it’s paired with the T-28. This will be the case for all its life.

Additional metamorphoses took place in the second half of the 1930s. Even though its prototype fit initial requirements, a request was made to redo the T-28 tank, installing a 76 mm gun. Perhaps the Grosstraktor’s armament was the cause. As a result of all these changes, the mass grew from 16-17 to 23 and then to 25.2 tons. The tank was medium, but only when it came to mass. Later, in 1933, the PT-1 grew into a convertible drive analogue of the T-28: the T-29. Another step was made in the development of heavy tanks. Work on the T-39 was finished. The tank weighed 90 tons. A full set of technical documentation was produced, and that’s it. The government didn’t want to spend 3 million rubles on building a prototype of this vehicle. In the end, the T-35 had no alternatives. Its mass in production increased to 50 tons.

The Soviet FCM 2C equivalent looked like this. The document states why the tank was never built: “Production of an experimental T-39 tank would take about 3 million rubles and at least a year.”

There were 5 types of tanks by 1935. The first was a reconnaissance tank, the T-37A. The second type was the most common type: the combined arms tank. This was the T-26, but it would be replaced by the convertible drive T-46. The third type was the operational tank, the BT. It could be replaced with the PT-1, but the idea soon died. The third was the quality reinforcement tank, the T-28. The manual calls it “medium weight”, but this was only a comment on its mass. In reality, it was counted among breakthrough tanks, hence its allocation to heavy tank brigades. As for the T-35, it was called a “special purpose powerful tank”. The T-28 was in an interesting position, since it could have been replaced by the T-29. The tank had identical armour and minimal differences in weight. Like the T-46, the tank was a failure, as was the T-43 convertible drive tank.

The system of Red Army tanks by 1935. The TG-1 was called a “powerful tank” in 1931 like the T-35, but not a “heavy tank”. The T-28 also counted as a breakthrough tank by 1935. It was medium only when it came to mass.

Now, let us return to the title of “best medium tank” as applied to the T-28. To start, no new work on the T-28 was performed. Development was sluggish since the tank was supposed to be replaced with the T-29. In 1937, correspondence referred to the vehicle as a heavy tank. In 1937 work was also done on the development of a breakthrough tank that could replace the T-29. The Kirov factory called their project T-29CN, and factory #185 called theirs the T-115 “convertible drive heavy breakthrough tank”. The T-28 was also called a heavy breakthrough tank in correspondence. It was medium only in weight, not in designation. 

The BT was in a very different boat. Its replacement was the convertible drive BT-20 (later A-20). The purely tracked A-32 grew out of that. Decree #198ss of the Committee of Defence within the Council of Commissars issued on August 7th, 1938, clearly sated which prospective tanks replaced new ones. The T-28 and T-35 breakthrough tanks would be replaced by either the SMK-1 or the T-100.

T-115, one of the prospective replacements for the T-28. Take special note of the type: “reinforced heavy breakthrough tank”.

The modern system of tank classification appeared by the end of May of 1940. The KV-1 was called a heavy tank and the T-34, the descendant of the A-20 and A-32, was called a medium tank. The lighter tanks were still complicated. The T-40 was called “amphibious tank”, “amphibious reconnaissance tank”, rarely a “small tank”. The manual called it a “light amphibious tank”. The T-26 was called a “support tank”. The designation “light” didn’t apply to it until 1944, and even then the name appeared in the NIBT Proving Grounds album that invented the names T-70M and T-40S that weren’t used by anyone else. The T-60 was then called a “small tank” and the T-70 was already a “light tank”.

The French send greetings to anyone who calls the Panther a heavy tank due to its mass. Pay attention to the weight of the Char Moyen Surbaissé or AMX 50B. This medium tank weighs nearly 58 tons.

Let us wrap up with some interesting facts about the difference between mass and class. Many call the Panther a heavy tank because of its weight. The French have their own opinions about this. Their AMX 50B, the tank that can be seen at the Saumur museum today, was called Char Moyen in 1953. This “medium tank” weighed 57,800 kg, so what does that make the Panther? The mass of the tank does not always line up with its designation. The Swedish Strv m/42 is another example. Its manual classifies it as a medium tank, but it was used as a heavy. The same thing happened to the EMIL family of tanks. They were going to be used as heavies at 28 tons just as they were at 45. Before trying to make conclusions based on what seems reasonable to you, try studying what the people of the time thought about it.

Original article by Yuri Pasholok.