“Do you feel how slender it is, Winston? The idea, of course, belongs to Big Brother, "he added, recollecting himself."
J. Orwell "1984"
Every person who is "fond of armor" has his own "favorite tank" or armored vehicle, which they admire for a long time and persistently. Anyone like, but for me such a BA, I emphasize, it was the BA, and not the tank, was the Swedish armored car of the 30s Pbil fm / 29. Moreover, I really wanted to establish its production in the form of a prefabricated model. Again, because its entire body could be very easily cast from epoxy in one piece! The fact is that his wheels were covered with armor, so the wheels themselves were not needed for him, but only the “quarters” visible from above, as well as a small tower and details made of “white metal”. Such a model in the West and in Sweden, for example, would have cost $ 40, no less, but I had no drawings for it. And then I just took it straight and wrote to the Swedish Ministry of Defense, to the public relations department, and to me … everything I asked from there was sent. It happened in 1995 and, of course, I was very grateful to the Swedes for the projections and materials sent. But then I remembered that if they had a BA with closed wheels, then we had a tank similar to it!
Tank BT-SV-2.
I started looking and just like that, I went to the Tsyganov BT-IS tank, which will be the story of this today. Along with the TG and "Dyrenkov's tank", it was included in the number of our prototypes, which largely determined the high level of Soviet serial tank building, although it still did not get into serial production.
Here it is - "handsome" Pbil fm / 29, costing 50,000 Swedish kronor, which seemed to the Swedes at that time an unbearable amount. Well, its cross-country ability was limited due to the armor hanging over the wheels, but it was not taken into mass production.
And it so happened that when W. Christie's tanks, as they say, "went" (which was described even in the 1935 comedy "Hot Days"), their tactical and technical characteristics turned out to be much lower than expected. In the same movie "Hot Days", the bulk of the tanks is T-26, and there is only one BT-2, and it constantly breaks down. Meanwhile, A. Dovzhenko at the All-Union Creative Meeting of Soviet Cinematographers in January 1935 said: “I will not reveal any military secret here if I say that in a few years we may have a war … There will be a huge world war, the participants of which we will definitely must be. … First of all, you need to prepare in advance…”Well, he urged, of course, to shoot the appropriate movie. But it was impossible to participate in the "huge world war" on … bad tanks ?! The heroes of the film, in passing, put some kind of "plate" there and the engine stopped breaking, and many after watching this "movie" also thought about the problem, but "what is the best way to make a BT tank?"
BT-IS. The folding shelves for storing the removed tracks are clearly visible.
Probably, similar problems with this vehicle plagued the young tankman of the 4th Tank Regiment from the Ukrainian Military District, Nikolai Tsyganov. True, he did not have a special technical education, but this did not stop him in 1934 from designing an automatic coupler for the T-26, T-27 and BT tanks. People's Commissar of Defense K. Voroshilov awarded him a gold watch for this, and in addition he received a promotion - he was promoted from junior commander to platoon commander.
BT-IS is one of the prototypes.
And then K. Voroshilov, for some reason, spoke to the tankers of the 4th tank regiment, and said that it was necessary to "create a new wheeled-tracked propulsion unit for the BT tank" so that it would become an even more powerful combat vehicle. Well, at least he told all this to engineers at some factory. But no, he said in a private tank regiment. And the commander of the UVO troops, I. Yakir, who was present here, immediately assigned the task of the People's Commissar to N. Tsyganov and those whom he would take into his group. That is, the talent of the inventor was recognized for him and “given the green light”. The group was reinforced with engineering personnel, and the work began, and for four months people worked 16-18 hours a day. By April 1935, both the drawings and a 1/5 life-size model of the tank were ready, on which there was a new propeller, which had three pairs of driving wheels and one pair of steered wheels.
This is how the transmission of the new tank looked "live".
But who exactly came up with the idea of creating such a tank, you can't say for sure today. For some reason, Tsyganov himself sincerely believed that this idea belonged to … Stalin, and that it was his idea, Tsyganov and his comrades were told by their "favorite Bolshevik commander" comrade Yakir. And he and his comrades wrote so directly to Stalin and Voroshilov about this: you, Comrade Stalin, put forward the idea, Comrade Yakir explained it to us, and we did it in the shortest possible time, fulfilling our party duty, here. And we decided to name the tank BT-IS (IS - Joseph Stalin). The guys were correct, to be sure. They correctly understood the party's policy, the time, and the current moment. Everything is exactly as described by George Orwell, only he was not talking about a tank there.
A team of enthusiasts is working on their brainchild. They do not yet know that very soon they will have to give explanations why they made a "wrecking tank", or maybe they were asked why they knew about the wrecking work of Firsov and his colleagues, but did not report back?
In response, Voroshilov ordered the necessary funds and a job at the tank repair plant No. 48 in Kharkov to build the BT-IS. Things there, however, did not go smoothly, so that Tsyganov even complained about the local engineers in the Central Committee. But, despite all the difficulties, in June 1935 the new tank was already ready, and its tests began, the progress of which was reported to Voroshilov personally. He demanded that in 1936, 10 BT-IS tanks based on the BT-5 tank should be made. In June-March 1937, the tanks were sent on the Kharkov-Moscow run, after which a number of improvements were made to the vehicle's design.
Scheme of the onboard transmission of the BT-IS tank.
The new tank was still the same BT-5, but differed from the prototype in that it had three pairs of driving rollers for wheel travel. A special synchronizer was also provided, which equalized the speed on the wheeled and tracked, which gave the tank the ability to continue moving in the event of the loss of one of the tracks. But the most important thing, of course, was the presence of six driving wheels, which made it possible to use more than 75% of the car's mass as adhesion weight, which should have increased its cross-country ability on wheels.
On the BT-5, a gear transmission was used from the drive wheels of the caterpillar track to the rear rollers of the track on wheels. Now all three pairs of rollers rotated from two horizontal and six vertical cardan shafts mounted above the wheels in the upper part of the body. However, the Christie-type candle suspension on the tank was retained, although the designers themselves placed the candles with springs on the tank in a different way. However, nothing good appears just like that: in addition to the synchronizer, the tank had to be installed, in addition to the synchronizer, also angular distribution boxes, upper gearboxes, numerous cardan shafts, a synchronizer shift drive, and a new fuel tank was installed at the stern. It also took a place to store the tracks removed from the wheels. They found a place for them on the folding side shelves, which, when moving on tracks, pressed against the sides of the tank.
Back view.
Test for overcoming natural obstacles.
During the tests, the BT-IS tanks were done on wheels from 1500 to 2500 km. At the same time, their propeller, despite the significantly greater complexity than that of the BT-5, showed both improved cross-country ability and high survivability. Tanks could move and, having lost one track, and even losing one or two road wheels. Although the tanks had shortcomings, the Red Army commission considered that the tank should be adopted for service, as it had clear advantages over its predecessor.
Tank BT-SV-2 in the snow.
It was decided in 1937 to prepare a series of five BT-IS vehicles. It was planned to install sloped armor on the sides with a thickness of 6 mm in order to protect the final drives and also to eliminate the shortcomings that appeared during the tests. Well, and in a year to produce 300 tanks of this type.
Four projections of the BT-SV-2 tank. Rice. And Shepsa.
Meanwhile, Tsyganov, as it often happened and happens with inventors, considered that everything had already been decided with the BT-IS tank, and took up a new vehicle based on the BT-7 with improved armor protection. They finished the tank at the end of 1937 and named it in the best traditions of that time: BT-SV-2 "Turtle" (SV - "Stalin-Voroshilov"). The main highlight of the design was the placement of the armor plates of the hull with very large angles of inclination: from 15 to 58 °. The bow was the same width as the hull of the tank, so the front idler tube on this tank was removed. At the same time, the suspension of the road wheels did not fundamentally change.
BT-SV-2 side view.
The main thing is that the body of the BT-SV-2 had practically no protruding parts at all, except for the caps of the springs on the candles of the vertical suspension, which remained standing upright. At the same time, the armor plates were removable and bolted to the body. For greater rigidity, internal fastenings were provided, dividing the reserve space into sections. The gas tank, which was in the stern of the BT-7, was removed, so that it also became inclined, and the tanks were installed along the sides.
Blueprint from the T-20.
The turret of the tank acquired a conical shape without a stern niche, which is why the radio station was placed in the bow of the hull, where, in addition to the driver, a radio operator was placed, who became the fourth member of the crew.
The experienced BT-SV-2 was made of ordinary steel 10-12 mm thick, but the real combat vehicle was planned in two versions at once. The first one with FD brand armor and a thickness of 40–55 mm, which should have protected the tank from 45-mm shells fired at it from any distance; the second option was designed for thinner 20-25 mm IZ grade armor, which protected the tank only from 12.7 mm bullets, however, from any distance.
Tests of the BT-SV-2 tank took place in the winter of 1937 - in the spring of 1938, and during this period the tank traveled 2068 km. It was noted that if the weight of the BT-SV-2 is 24-25 tons, then its undercarriage will be too weak for it. It was planned to build a tank with full armor and fire it from a cannon. But here for good for worse (today it is impossible to say for sure) in early 1938 N. Tsyganov and two of his employees were arrested by the NKVD. Fortunately, they did not shoot him, but they shook his nerves pretty much, and most importantly, they were no longer allowed to invent tanks. Moreover, in March 1937, a large group of engineers from the KhPZ was arrested, and, in particular, A. Firsov, the head of the tank design bureau, instead of whom M. Koshkin, the future creator of the T-34 tank, was appointed. N. Tsyganov himself later fought and died of his wounds in the spring of 1945, a little before the Victory, but it’s good that, at least, he did not die in the camp.
Moreover, the issue of bringing BT-IS to mind from the agenda after the arrest of Tsyganov was not removed, that's even how, and the Main Armored Directorate of the Red Army in October 1937 issued an order for the KhPZ for the BT-20 tank (under the new designation A-20), which in metal they were handed over in 1939. And on it, the wheel drive was also on all six wheels, like the BT-IS tank, and the upper armor plate had an inclination of 53 °.
Interestingly, the BT-SV-2 model is produced today in the version of a paper gluing kit.
Now let's look at the minuses and pluses of these developments - the BT-IS and BT-SV-2 tanks in relation to their development by industry and troops. With the same armament as the base tank, the BT-IS had a slightly higher speed, significantly higher off-road cross-country ability, but … structurally, it was very complex. All this abundance of shafts, couplings and helical gears significantly increased the cost and complicated the design of the tank, as well as complicated its maintenance. And for what? For the tank to drive better on a plowed field and in the snow? All this could be achieved by placing the tank on wider tracks! That is, in reality, this design did not promise much benefits. But the nodes that could break in it in comparison with BT-5 and BT-7, there were much more and it was possible to fear that … they would break, since the technological level of the Soviet industry was then very low.
The team of creators of BT-IS. N. Tsyganov is on the far left.
Even more interesting is the BT-SV-2 - a handsome tank, something extraordinary for its time. But … with the same armament as on the BT-7, and worse cross-country ability due to its narrow tracks! That is, it would have been necessary to put wider tracks on it, make the upper armor plate wider for a wider turret shoulder strap, put a larger turret on it, with a larger-caliber gun, the fifth wheel, and in the end we would have got the same T-34, only available with shielded chassis. That is, no, our military specialists were not at all inert then, but they were not dreamers that, pulling up their pants, they were ready to wander straight across the sea. They soberly assessed both the level of our industry at that time, and the army's capabilities in servicing complex equipment, but at the same time they did not shy away from innovations - "why not try an interesting proposal?" That is, they realized that the BT-SV-2 is good now, this very minute, maybe even too good. But by a wave of a magic wand, thousands of such tanks will not appear at once, which is why they eventually abandoned it, like the BT-IS! They were smart people and they did the right thing then!
