One of the "highlights" of W. Christie's tank was that it could very easily be "taught to swim". The designer himself even developed one such tank with a coffin-shaped body, a 75-mm French gun (in service with the US Army) Model 1897, and it was even tested by the US Marine Corps. The Marines did not like the tank, but the very possibility of making an amphibious vehicle out of his wheeled-tracked tank, as well as his talent as a designer, Christie confirmed. Well, when the "Christie tank" came to the USSR, of course, they tried to improve it even more and create a "universal amphibious tank" on its basis.
Tank PT-1.
Work on the new vehicle began literally the very next day after the Christie's tank "went to the USSR." A project was created in the KB-T design bureau at the Krasny Proletary plant, and in 1932 a new tank rolled out of the factory gates. The project was supervised by Nikolai Aleksandrovich Astrov, the future creator of a whole series of domestic amphibious vehicles. Moreover, it was planned to create not some kind of "tank on floats", but using the components and assemblies of the BT series tanks, a tank with a displacement hull and more powerful weapons than the base vehicle. That is, a tank was created, which, according to its creators, was supposed to surpass all foreign tanks of this type, both reconnaissance and amphibious tanks, and at once in all indicators: firepower, armor protection, and, of course, driving performance. At the same time, it was not considered as a replacement for BT tanks. It was supposed to be a tank of "quality reinforcement" of small amphibious tanks so that it could provide them with artillery support when crossing water obstacles.
Tank PT-1 on wheels.
Actually, the design of the PT-1 tank (which it received the designation - "amphibious tank -1") differed little from Christie and BT tanks: the engine and transmission were in the rear, the turret was the fighting compartment, closer to the bow of the hull, but in the compartment They put not one, but two people at once - a driver and another gunner-radio operator, which was not on Christie's tank.
PT-1. Machine guns sticking out of the turret and a riveted star on the front armor plate are clearly visible.
The armored body of the increased volume compared to the BT-2 and BT-5 tanks was assembled from rolled armor sheets 10 and 15 mm thick. At the same time, the very design of the hull was well thought out by the creators of the tank. It turned out that she also provides buoyancy to him, and with stability, everything is in order, and afloat he has little resistance to movement. To accommodate the guns and machine guns (there were four of them on the tank, and three in the turret!), A cylindrical tower was used, similar to the BT-5 turret of an early release, that is, it had a smaller aft niche than on the 1935 tanks. the crew left it through a common hatch on the turret roof and two hatches on the hull roof at once above the driver's and gunner's heads.
PT-1 on trials.
The PT-1 was armed with a 45-mm 20-K cannon and, as already noted, four DT-29 machine guns, one coaxial with a cannon, one in a ball mount in the upper right frontal hull sheet and two in ball mounts in the sides of the cylindrical tower closer to the stern niche. Of course, such an arrangement created certain difficulties for its use. Why, however, did such a solution appear? It was believed that in a combat situation the turret of a tank could be jammed. But the tank will still be able to continue the battle if it has a frontal machine gun in the hull and machine guns on the sides of the turret. Moreover, it was believed that such a tank, forcing a trench, could put it “in two fires”. By the way, that is why the first T-26s had two towers to shoot through enemy trenches in both directions, and the TG tank had exactly the same armament. Ammunition included 93 rounds for the cannon and 3402 rounds for machine guns in 54 disks.
Three projections of the PT-1 tank.
It was planned to supply the tank with a 300 hp diesel engine. PGE, however, its fine-tuning dragged on and together with it, a twelve-cylinder, aviation, liquid-cooled M-17F engine with liquid cooling of 580 hp was installed along the longitudinal axis. with. The engine cooling system provided for the ability to cool it with air on the move and water afloat. The circulation of seawater was ensured due to its suction by propellers through the holes in the sides of the hull. Accordingly, the fans, which drove air when driving on wheels through the cooling radiators, were disconnected from the engine on the water. It seemed that the idea was rational, but tests "in metal" showed that the engine is very much cooled at the very beginning of the voyage, but not enough when it is in the water for a long time, so the water suction by the propellers was not very effective. The fuel supply in the side and aft gas tanks was 400 liters, which allowed him to travel 183 km on tracks, and 230 km on wheels.
PT-1. Back view. The aft niche of the tower, as you can see, is very small.
As for the chassis of the tank and its transmission, it can be stated without exaggeration that this was not the case at that time in any country in the world, including the birthplace of Christie's tanks - the USA! Indeed, in addition to two propeller drives, it also had final drives for all eight road wheels, that is, they were all leading when the tank was moving on wheels! At the same time, the two front and two rear pairs were steerable! But the most important highlight of this design was that the drive shafts of the drive wheels of the gearboxes, as on the BT-IS tank, did not have. The gearboxes were located in the road wheels themselves, which was carried out for the first time in the history of tank building. Thanks to this, the drive was greatly facilitated and, accordingly, the center of gravity of the tank was lowered.
PT-1A with a turret from BT-5.
The tank was controlled by a steering wheel (movement on wheels) and levers (movement on tracks), and on servos.
The tank was supposed to move afloat with the help of two propellers enclosed inside the tunnels at the rear of the hull. It was believed that this would save the screws from damage and, moreover, no water greens would wrap around them. Again, it was supposed to do without rudders and control the tank by reversing the screws. In addition, the tank was equipped with a rather complex system for pumping fuel from the front tanks to the rear ones, in order … to control its trim afloat like on a submarine. For some reason, the fuel transfer pumps were out of order all the time, so the system turned out to be inoperative. But the idea of turning the exhaust pipes upward when entering the water turned out to be quite successful, and water did not get into them.
The tank is afloat.
The suspension of the tank was similar to the suspension of the Christie tank and the BT-2 and BT-5 tanks, but telescopic shock absorbers were added to it. The idler wheels also had external cushioning. The caterpillar consisted of large-link tracks 260 mm wide. It was decided to install a 71-TK-1 radio station on the tank, and a long handrail antenna was installed on it, which was mounted not on the tower, but along the perimeter of the tank hull. The tank, however, did not have internal communications.
The tank comes out of the water.
The speed on water was 6 km / h, on a caterpillar track - 62 km / h, on a wheel speed it reached 90 km / h.
Tank in the factory yard.
The car was considered so successful that in the resolution of the STO "On the system of tank armament of the Red Army" of August 13, 1933, it was stated: "Since 1934.to begin the gradual introduction into production as an operational tank of the PT-1 amphibious vehicle in such a way that, from 1936, it will completely switch to the expanded production of this tank on the basis and at the expense of the production of the BT tank. But … something prevented the planned decision from being implemented. What? It is customary to say that this is “the general technological backwardness of Soviet industry in those years. There was undoubtedly backwardness, but how exactly did it manifest itself in this particular case? Yes, in nothing - after all, they managed to make a tank! However, it had an irreparable drawback (the downside of its merits!), Because of which it did not go into the series - gearboxes in wheels! That is why Tsyganov on his BT-IS and installed gearboxes in the upper part of the case, that in the wheels they were very difficult to maintain and … how did they generally work in the event of water, dust and dirt getting into them? Of course, hypothetically, one can imagine that they were completely sealed. And then the Red Army could well become the first army in the world, whose main battle tank would be a universal high-speed wheeled-tracked (in that case, of course, if its advantages would have blocked during operation the advantages of conventional BT, otherwise it would have remained "Amphibious reinforcement tank"), and even amphibious tank. But this is purely hypothetical. In reality, neither the PT-1 tank (nor its improved version of the PT-1A, distinguished by an elongated hull, one propellers and reinforced armor protection) never made it into the series. Its chassis, which had as many as eight gearboxes in the wheels, turned out to be very complicated (and expensive, of course!). The shafts of sufficient length and angular gears should also be of high quality. Therefore, the decision of the STO of June 19, 1935 decided to “leave the BT tank in service. Refuse to replace it with PT-1”. The conclusion, apparently, was this: "The tank cannot be very complex and contain dubious details in its design."
Camouflage of the PT-1A tank.
