The First Firebreathing KV

The USSR was the first country to mass produce flamethrower tanks. Initially these were chemical tanks, whose primary purpose was to deploy chemical weapons. Nevertheless, the KhT-26 chemical tank accepted into service in the summer of 1932 was already a dual purpose vehicle. It could still deploy chemical weapons, but now its main weapon was a flamethrower. The KS-2 flamethrower developed by the Compressor factory was the first mass produced tank flamethrower. The pneumatic system could spew fire 30-45 meters away, not too far, but not too bad for a first try. The KhT-26 was the USSR’s first mass produced flamethrower (chemical) tank. The KhT-130 on the chassis of the T-26 tank with a cylindrical turret and KhT-133 based on the T-26 with a conical turret and turret platform followed. The T-46-1, the T-26’s replacement, was also supposed to be a chemical tank, but it never went into production. The flame throwing range gradually increased, but still was not enough. Other platforms were considered for flamethrower tank production, but the chemical BT never took off.

The issue of putting a flamethrower into a KV-1 was first raised in August of 1940.

It was clear by the second half of the 1930s that the T-26’s time was coming to an end. The conflict at Khalkhin-Gol and the Winter War showed the weaknesses of both the chassis and the flamethrower. Five organisations were working on tank flamethrowers by 1940. In addition to Compressor, NATI, GSKB-47, factory #37, and factory #174 were all working on their own flamethrowers. Factory #174 slowly emerged as a leader thanks to I.A. Aristo, a developer of a number of chemical tanks. Aristov supported the idea of a gunpowder flamethrower that had a greater range. The idea of putting flamethrowers onto BT-7, T-34, T-126, and KV-1 tanks was voiced in August of 1940. Two types of flamethrowers were created for the BT-7 and T-34: a pneumatic one and a gunpowder one. The T-126 (later T-50) and BT-7 variants remained higher in priority.

A leader emerged in the flamethrower race by early 1941: factory #174’s ATO.

Factory #174’s ATO flamethrower was considered as the most likely candidate to enter service in early 1941. Factory trials were carried out in February. The range of 70-75 meters made it more interesting than its competitors. The Council of Commissars and Central Committee of the VKP(b) signed decree #525-224ss “On arming the KV, T-34, and T-50 tanks with flamethrowers” on March 13th, 1941. The ideas voiced in August finally had a path to life. Each tank regiment was supposed to have 20 KV tanks with ATO flamethrowers. This was not only the KV-1, but also the prospective KV-3 (the first tank to carry this designation). The history of flamethrower-armed KVs at the Kirov factory ended up almost as dramatic as that of the flamethrower on the T-50 tank.

This flamethrower had the best design.

The choice of Aristov’s design had several reasons. The weapon was quite compact and weighed just 45 kg. The ATO’s designers initially aimed at making it take up as little room inside the tank as possible. The KV-1 and T-34 already had a DT mount that could be modified to take a flamethrower. This idea had the additional advantage of making it possible to convert the tank back and forth. This didn’t work out in practice and the mount had to be modified, but it was still easier to install this flamethrower than other ones. Factory #174’s ATO as also developed to avoid impacting the main armament. The tank could carry 10-15 shots for the flamethrower while not impacting the main ammunition stowage capacity. Only the amount of DT magazines was reduced, not a big deal considering that the bow machine gun was replaced.

The decision to mass produce the future ATO-41 was made in March of 1941. This is when work to install the flamethrower into a KV tank began.

Decree #525-224ss called for starting production of KV tanks with flamethrowers in July of 1941. 500 of them would be the KV-3 (these were still the T-222, the improved T-150) built at the Kirov factory, 150 would be KV-1s built at ChTZ. An addendum was later made for an additional 50 KV-1s with flamethrowers at the Kirov factory. Kirov factory’s SKB-2 began to work on a flamethrower mount quickly and a first variant was completed by March 21st, 1941. L.Ye. Sychev and G.A. Malinov were allocated to this project. The factory went its own way. The radio operator’s machine gun remained in place and instead the ATO was installed to the right of the driver. A separate mantlet was installed here. The flamethrower could be aimed vertically and horizontal aiming was achieved by traversing the hull.

The first variant of the flamethrower in the KV. The mantlet was a bad idea but the fuel tank location was retained later.

The KV’s flamethrower design stabilised in April of 1941. One issue popped up at this point. Development for the KV-3 was still considered a higher priority. In March of 1941, the T-222 was replaced with the heavier T-223. This was the tank that the ATO was developed for. The model reviewed on May 8th, 1941, didn’t have a flamethrower, but it was depicted in the cutaway blueprints. The reworked ATO mount had a mantlet that covered up the big port the initial design had. The location of the fuel tank on the right side next to the front diesel tank made it necessary to remove the right hand ammo rack and DT magazine rack. The change of the KV-3 was not a big problem. The mount was the same and only had to account for thicker armour.

The second variant accepted into service. It was developed for the KV-3 (T-223) but built for the KV-1.

This kind of commonality really came in handy. Work on the KV-3 dragged on, but the clock was ticking. There was also some worry about the rate at which ATO flamethrowers were being developed. The flamethrower was accepted on May 8th, 1941, and the mount for the T-34 was accepted on May 20th. The flamethrower designated ATO-41 was going to be produced at the Ukhtomskiy factory in Luberetsk. Meanwhile, the work on the ATO-41 for the T-50 dragged on. It was not installed on any tank aside from the experimental one. As for the KV, the blueprints were approved on June 14th, 1941. But only the KV-1. Factory #174 was ordered to deliver blueprints of the improved ATO-41 and one sample to the Kirov factory by June 20th, 1941. This decision was made as a result of a meeting that was held on June 12-13th. Trials held on June 12th showed issues with the automatic mechanism, plus the range was only 70 meters. An improved flamethrower was installed on the next day, June 13th. The range using a new mixture developed b NII-6 increased to 100 meters, but there were still occasional misfires. Nevertheless, the ATO-41 was accepted into production after the correction of defects.

This is what the flamethrower mount for the KV-1 looked like.

On June 24th, 1041, S.A. Ginzburg and I.S. Bushnev signed temporary technical requirements for installation of “product 41” as the ATO-41 was still called. A brief instruction manual was also prepared. Everything was fine on paper, but there was one small snag. Ukhtomsky factory was having a hard time with the ATO-41 and there was no hope of July production. The factory could not even meet the very sparing quota of 25 units delivered in July, finishing only 17 by the end of August. 10 hulls with flamethrower ports were built to at least make use of this small amount of flamethrowers. It’s no wonder that Kirov factory was so excited about single shot TOG flamethrowers developed by GSKB-47.

Only 4 flamethrower KV-1s were delivered, one of which was a conversion from a repaired vehicle.

The situation was even worse than it might seem. Kirov factory received only four flamethrowers that could be installed on tanks. 3 of these tanks were new and one came from repairs. The rest of the hulls built for the ATO-41 had their openings sealed. Some researchers call the KV-1 with a flamethrower KV-6, but that is nonsense. The name KV-6 refers to the former T-222 that was pitched for production at ChTZ. This tank never made it off paper.

No Soviet photos of KV-1 tanks with flamethrowers exist. These tank tanks were captured in October of 1941 and fielded by the 58th Infantry Division. One of them has an ATO-41, the other has a patch over the opening where it was supposed to be installed. 

All flamethrower KV-1s and at least some of the tanks with patches ended up in the 124th Tank Brigade. No special information about their service survives, but one can deduce that they did not perform very well. The cartridges that the ATO-41 used to fire frequently misfired. There was a lot of discussion about this between factories that were involved in production of the flamethrower and ammunition in the fall of 1941. Meanwhile, the combat career of these tanks was short. On October 8-10th, 1941, the tanks fought around Uritsk (modern day Ligovo, a district of St Petersburg), on Petergof highway. The tanks did not get a chance to make use of their flamethrowers. All were lost either due to artillery fire or mines.

Captured tankers were forced to repair these tanks. One of them can be seen in the turret, another is tinkering with a barrel on the left.

The story of the KV-1s from the 124th Tank Brigade continued. One of the tanks with an ATO-41 and at least one with a patch over its port ended was damaged, but not destroyed. Captured tankers returned both tanks into service in a field workshop near Krasnoye Self. Sometimes these tanks are assigned to the 12th Tank Division, but private photos that pop up on eBay contradict this version of events. These tanks were actually used by the 58th Tank Division. In March of 1942 the captured KV-1s were used in battle for Myasnoy Bor, but without much success.

The same tank in the winter of 1941-42.

In conclusion, the idea of the ATO-41 mount in the front hull was deemed poor. Its effectiveness was not much greater than the TOG. In the fall of 1941, G.A. Manilov and other Kirov factory designers in Chelyabinsk began to work on another place for the flamethrower. The result was the KV-8 tank, which ended up being much more common. As fate would have it, these tanks also made their debut at Leningrad a year later, as a part of the Sinyavino operation.

Original article by Yuri Pasholok.