Wednesday 2 February 2022

A Flame Throwing Alternative

The USSR was one of the few nations that seriously explored tank flamethrowers in the 1930s. Initially there were plans to install a flamethrower on the T-18 (MS-1) tank, but the adoption of its replacement, the T-26, led to a real breakthrough. The result was the KhT-26, the most numerous chemical (flamethrower) tank. Unlike the two-turreted T-26, which was produced relatively briefly, the KhT-26 created on its chassis was in production until 1936. It was replaced by the KhT-130, an improved version based on the single turreted T-26, and then the KhT-133, the same type of vehicle based on the T-26 with a sloped turret and hull superstructure. In total, over 1200 chemical tanks on the T-26 chassis were built, not including the KhT-27 and KhT-37. However, a considerable flaw in these tanks was discovered even before the war. Their bulletproof armour made them too vulnerable.

Motivation from the very top was necessary to start development of the TOG flamethrower.

Attempts were made to convert other tanks, particularly the BT series, into flamethrower tanks. The first experiments began in 1933 and the last ended in 1941. For various reasons, work did not progress past prototypes and pilots. Come 1941 it was also clear that existing tanks were unsuitable for conversion into flamethrower tanks. Their thin armour made them an excellent target and a death sentence for the crew. Work stopped. Some KhT-133 tanks that were already produced received applique armour, as did the KhT-134 that was developed out of the KhT-133. A flamethrower similar to the one used on the KhT-134 was supposed to be installed on the T-126. However, the time of old flamethowers, just like that of old tanks, was at an end. There were much more suitable tanks and flamethrowers available by 1941. 

Diagram of the first TOG flamethrower.

Several organizations worked on tank flamethrowers at the same time. In addition to the Compressor factory, a leader in this field, the NATI institute, factory #174, and GSKB-47 design bureau developed flamethrowers. In case of the latter, the ATOG flamethrower was developed by a group led by the chief of the 6th department of GSKB-47, S.I. Novikov.

Factory #174 overtook its competitors. The ATO-41 gunpowder flamethrower created under the direction of I.A. Aristov was accepted into service with the Red Army. Preparations for producing it at the Ukhtomskiy factory in Lubertsy began in the spring of 1941. Nevertheless, GSKB-47 continued to work on its flamethrowers. Novikov's best known design was the FOG flamethrower that was used on T-34 tanks and sleds starting in 1942. His other invention, the single shot TOG flamethrower, is much less known. It was developed in the summer of 1941, went through trials, and there were even plans for mass production. 

Only three days elapsed between GKO decree #115 and the start of trials. 

The TOG is not mentioned in GABTU corresponence until July of 1941, indicating that this was a grassroots project. The TOG was not a new design. A similar flamethrower was developed by GSKB-47 back in 1938, but rejected allegedly due to a lack of production facilities, even though trials were still conducted in 1940. In reality, it was more likely that no one bothered with this project when other flamethrowers were a priority. No one remembered this project by 1941 until the TOG made an unexpected comeback in the summer. Novikov's other project, the explosive charge driven FOG flamethrower. It was met positively, but production was progressing slowly. As a result, GSKB-47 clearly made a power move. On July 11th, 1941, Deputy People's Commissar of State Security I.A. Serov made a report describing the situation with the FOG and other projects. Involvement of the KGB had an effect. GKO decree #115 "On production of flamethrowers and their trials" was published on the very next day. It called for production and trials of the flamethrower within three days' time.

Installation of TOGs on a KV-1 tank.

The GSKB-47 was clearly ready for this turn of events, as trials of the TOG flamethrower took place right on schedule: July 15th, 1941. In the trials documentation, Novikov is described as a representative of the Ukhtomskiy factory, clearing up any doubt as to who produced these flamethrowers. The device itself consisted of a 1300 mm pipe 145 mm in diameter. 21.4 L of fuel as placed inside. A nozzle and a pilot flame to ignite the fuel as it exited the nozzle were located on one end. The calculated range was 125 meters, but in trials with fluid developed by NII-6 it only reached a range of 90 meters. As an aside, the issue was with the fluid, not the flamethrower. Calculations showed that three flamethrowers could be placed on each fender of a KV-1 tank. Despite some drawbacks, this solution was deemed to be promising. The commission proposed production of a 300 unit pilot batch after improvements.

Final 25 L variant of the TOG.

Trials of the improved TOG took place on July 28-29th. The diameter of the pipe was increased to 150 mm and the volume of fuel to 25 L. This time the flamethrowers were fired from a test bench instead of a real tank. As before, two electic triggers were used to fire. 16 shots were made in total. The TOGs worked flawlessly. There were complaints about the fuel once again (two types of mixtures were used), but the range increased. NII-6's viscous fuel had a range of 110-115 m, plain mazut had a range of 70-75 m. The final variant of the TOG was deemed to have passed trials and approved for experimental production. The real approval was given even earlier by Council of Commissars decree #5830 on July 26th.

Second A-34 prototype with TOG flamethrowers, August 1941.

A new flamethrower piqued the interest of tank factories, primarily the Kirov factory, which built only a handful of KV-1 tanks with ATO-41 flamethrowers. The TOG had the advantage of placing the flamethrower outside of the fighting compartment and not needing to make alterations to the vehicle. In August of 1941 the factory suggested installation of 250 TOGs (6 per tank) on KV-1s, but for a number of reasons this was never done. Nevertheless, the pilot batch of flamethrowers was still produced at the Ukhtomskiy factory.

Firing the flamethrower.

Events took a different turn at factory #183, where T-34 flamethrower tanks were supposed to be built. A set of six TOGs was installed on the second A-34 prototype (serial number 311-18-3). Two armoured shells were installed on the sides of the tank with three TOGs each. The trials were attended by People's Commissar of Tank Building V.A. Malyshev himself. The trials were a success; NII-6's fuel had a range of 110-130 meters, more than the ATO-41 flamethower. The flamethrower shells were fired upon with incendiary bullets, which did not cause them to ignite. Approval was given for installation of TOG flamethrowers on T-34 tanks in production.

The same A-34 tank in Chirchik, marks from the TOG flamethrower shell can be seen.

It seemed that the story was over, but Malyshev made a mistake. The whole business with the TOGs was a temporary solution. Malyshev correctly saw the ATO-41 as a long term solution. Unlike the ATO-41, Novikov's flamethrowers could not be aimed, although they were fine as a temporary measure. Therefore, as soon as there was some progress on ATO-41 production, Malyshev gave the order to cancel installation of the TOGs. That was a mistake. In October of 1941 the Ukhtomskiy factory was evacuated, and so there was no facility to produce either the ATO-41 or the TOG, neither an ersatz nor permanent solution. Towards the start of 1942 a decision was made to temporarily install the FOGs on the sides of T-34 tanks. This solution was temporary, but still went into production, and deserves a separate article.

Factory #112 designed an improved version of the TOG mounting, but it was never used.

The sled with FOG flamethrowers and their installation on the sides of tanks were not very good ideas, and in March of 1942 a proposal was made to return to the TOGs. 400 units were planned for Q2 of 1942, of those 150 would be installed on factory #183 and STZ T-34 tanks, 100 more on factory #112 T-34 tanks. Factory #112, a leader in similar solutions, even developed a new mounting for the TOG. Alas, it was not to be. While these preparations were made, the ATO-41 finally turned up in sufficient numbers, the the ATO-42. The TOG never made its comeback.

POTOG, a variant of the TOG developed by M.S. Ozerskiy, May 1942.

Finally, let us mention an attempted modernization of the TOG made in May of 1942. This time the work was organized not by Novikov, but by M.S. Ozerskiy, lead engineer at factory #222. This variant was named POTOG (piston TOG). Instead of replaceble bushings the flamethrower used a simple piston, which improved reliability and cleared the tube after firing. The POTOG was smaller in size. Each one carried only 10 L of fuel, but 20 units could be installed on one tank instead of just 6. Ozerskiy's design proved unnecessary for the same reason as the original TOG, although later he worked on the ATO-49 flamethrower that was used on the OT-54 tank.

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