Friday, 2 September 2022

Tsyganov's Armour

Additional armour developed by Engineer-Major N.F. Tsyganov, author of the BT-IS and BT-SV

Plenty of tank designers were among those who were repressed in the 1930s. 1937-38 was the most difficult period where a number of designers and military personnel linked to tank production were either executed or ended up with lengthy prison sentences. However, history sometimes lumps the latter in with the former. For instance, A.O. Firsov (chief designer of the T2K design bureau at factory #183) died in 1943 of natural causes and was not executed as is sometimes written. There are even more surprising cases where the allegedly executed party remained working at their old place of employment. For instance, Nikolai Nikolayevich Kozyrev, the chief tank designer at factory #37 and author of the T-37 and T-37A amphibious reconnaissance tanks, would have been very surprised to find out that he was executed. Kozyrev didn't even leave factory #37. It's true that N.A. Astrov replaced him as the head of tank design, but Kozyrev remained in important positions. By the fall of 1941 he occupied the post of chief engineer of factory #37. After evacuation to Sverdlovsk he continued working on tanks.

Tsyganov's BT-IS tank. The drives to the wheels can be seen. The BT-IS was an 8x6 vehicle, i.e. 6 of the wheels were powered.

The main hero of this article would also be quite surprised to find out that he had been repressed. Nikolai Fedorovich Tsyganov left a large mark on Soviet tank building. He enlisted in the Red Army in 1930 and completed the Regional Auto-Tractor Course of the Ukrainian Military District in April of 1932. This kicked off his career as an inventor. Tsyganov's first invention was an automatic linkage for evacuating tanks from the battlefield. Tsyganov later moved to improving BT tanks. This work is known under the designation BT-IS. Tsyganov directed the creation of a system that powered six of the BT's road wheels instead of just two. Thanks to this invention, the tank's off-road mobility increased drastically. Experiments were first performed on the BT-2 chassis and later moved on to the BT-5. Mass production of the BT-IS was discussed but never took place.

Tsyganov and the BT-SV-2, his most advanced creation.

Tsyganov also developed a further modernization of the BT known as the BT-SV. This tank has sloped armour and an expanded crew with two men in the driver's compartment. No doubt the BT-SV had an influence on the development of the BT-20 (A-20) tank and later the T-34. Tsyganov's work continued in 1937-38. An adjunct named Adolf Yakovlevich Dik arrived at factory #183 in the summer of 1937. Dik criticized the BT-SV harshly. A separate department was formed under Dik and some even credit him as the father of the T-34, even though his contribution was limited to the diagonal positioning of the Christie springs. Dik's foul character ruined his relationship with factory #183's design staff in general and Tsyganov in particular. The latter sent a furious letter to Stalin on October 26th 1937 about the failure of the factory to set up BT-IS production. He did not name Dik since he didn't know anything about his job and Dik's business trip at the factory concluded on October 18th. However, it seems that the letter caught up with Dik eventually. The damage was done the BT-IS never entered mass production, remaining an experiment. It's worth repeating that the BT-IS and BT-SV had a direct influence on the appearance of the T-34 tank.

Tsyganov fought in a number of battles, including the Battle of Stalingrad. For his heroism he was awarded with the Order of the Red Star.

Dik got his just desserts. He was fired on August 7th 1938, quickly arrested, sentenced to 3 years in prison in July of 1940 but actually only released in June of 1947. Many also write that Tsyganov was repressed as well, but Nikolai Fedorovich would have been quite surprised at that assertion. No one fired him, but rather in 1938 he was assigned to teach at the RKKA Academy of Mechanization and Motorization. One can argue that this was a sort of banishment, but a 3 year stint as a teacher and "graduation" in 1942 with the rank of Engineer-Major is hardly a punishment. Tsyganov had the opportunity to continue his tank design career, but he chose a different direction: the front lines. The 102nd Tank Brigade was formed on March 5th 1942. Tsyganov was assigned as the commander's technical deputy. The brigade was included in the 4th Tank Corps.

T-34 tank with reinforced concrete armour, NIBT proving grounds, June 1943.

The brigade saw its first battle for the Gorschechnoye village in Kursk oblast on June 30th 1942. On the first day the brigade reported 15 tanks knocked out and destroyed at the cost of 4 burned out T-70s. Heavy fighting continued, and the brigade (mostly consisting of T-70 and T-60 tanks) came under a heavy blow on July 2nd. Only small elements of the brigade managed to escape encirclement. This was not the end of the fighting as the brigade was reinforced on July 10th. Its tanks took part in fighting for Korotoyak. The brigade with the rest of the 4th Tank Corps was moved to the Stalingrad Front in late August. Here the 102nd Tank Brigade took part in Operation Uranus. As of November 19th it had 31 T-34 tanks and 10 T-70s. The brigade liberated Erik, the Krasniy Skotovod farm, crossed the Don on November 23rd, and linked up with elements of the Stalingrad garrison on the next day. The brigade took part in encircling the Voronezh group in January of 1943. In February, the brigade was renamed 22nd Guards Tank Brigade. All this time Tsyganov served as his post, restoring tanks damaged in battle. Under his guidance, the brigade repaired as many as 20 tanks in just 3-4 days.

The armour was built from sections so it could be replaced.

Tsyganov was recalled to the reserve of the Central Front where he served as an engineer-instructor in the usage department. This was because Tsyganov decided to continue his design work. This time he aimed to develop protection from new types of enemy shells, including HEAT. He developed additional armour that would protect the tank from all-around fire. Two types of armour were developed and built in the spring of 1943. Both types arrived at the NIBT proving grounds on June 6th 1943. Tsyganov came with them.

Even though the combined weight of the armour reached 9 tons, the rotation of the turret was not significantly affected.

The intention was to make armour that was easy to produce. They could be built by repair workshops, which made their distribution simpler. Both types of armour were about the same in design. Hardpoints were welded to the hull and turret of the tank. The armour blocks were then attached to them with bolts. A 150-550 mm gap remained between the armour and hull.

It was difficult to replace the armour blocks due to their weight.

The first type of armour used reinforced concrete blocks. The turret was covered with six blocks 120-150 mm thick. Each block was reinforced with metal ribs. The ribs were bolted to girders that were also attached together. The hull sections were built in a similar way, but there were more of them: 22 in total (10 on the sides, 6 front, and 6 rear). This was the simplest design, but the weight of the armour and hardpoints reached almost 9.3 tons.

The second type of armour consisted of metallic sections filled with sand.

The design of the second type of armour was similar. There were 9 turret blocks and 20 hull blocks. Each block was built from 3-4 mm thick sheet steel and filled with sand combined with a resin that held it together. This was an even heavier design at 12.76 tons. Armour blocks also caught on each other so 360 degree fire was not possible.

Trials showed that the turret blocks caught onto the hull blocks, making 360 degree turret traverse impossible.

The prototypes were sent to Kubinka for penetration tests, but the proving grounds staff only examined the design. The turret traverse speed was not impacted as much as the extra weight could suggest. A regular turret could be turned all the way around by hand in 2 minutes and 20 seconds. The turret with extra armour took 2 minutes and 42 seconds. The idea of removable segments was interesting, but since each one weighed 330-700 kg it was impossible to move them without a crane. The biggest problem was weight. The T-34 already had a problem with increasing weight, and this move added another 9-13 tons.

The metallic armour was even heavier than the reinforced concrete.

The conclusions were rather diplomatic. The armour was not discarded outright, but rather reserved for special use. This was code for "thanks but no thanks". Bad news from the front came soon after the trials were held. T-34 tanks with extra armour developed by factory #112 came under fire from German 88 mm Pak 43/41 guns. The fact that this armour was designed to withstand completely different weapons was disregarded. The topic of extra armour died for some time and was only revived thanks to Tsyganov. Tsyganov was one of the engineers who initiated a study of knocked out tanks that took place from January 30th to March 1st 1944 near the Vetkhin village of Rechniskiy district. These were primarily T-34 tanks. The conclusion of this study was that the location of ammunition racks should be revised. The question of spaced armour was also revived. Tsyganov also drew attention to the new German Panzerfausts. This work had its results and the spaced armour used in the Berlin operation came about thanks to it.

The proving grounds did not shoot at the armour and only studied it.

Alas, Tsyganov did not live to see victory. He was fatally wounded in the head on January 20th 1945 and died on January 24th in the rank of Engineer-Lieutenant Colonel. He was decorated many times throughout the war. His last award, the Order of the Patriotic War 1st Class, was posthumous. Tsyganov was one of many talented engineers who preferred to serve on the front lines of the Great Patriotic War rather than stay in a design bureau.  He made a significant mark on Soviet tank building.

No comments:

Post a Comment