Today, unmanned aerial vehicles are quite widely represented on the battlefields, but their first full-fledged debut was the Second World War. Even before the war in the USSR, remotely controlled tanks and tankettes of various types were actively tested and then produced. The teletank could be controlled by radio communication from a control tank, which could be located at a distance of up to 500-1500 meters, together they formed a telemechanical group. A telemechanical group of TT-26 and TU-26 was produced before the war in a small series (55 vehicles); by the beginning of World War II, the active army had at least two such battalions. At the same time, the greatest successes already during the war in this field were achieved by the Germans, who quite massively use Borgward teletankettes and Goliath self-propelled mines.
And if a lot is known about the use of unmanned armored vehicles, then much less is known about work in the field of ultra-small submarines that could be controlled by radio communications. Meanwhile, before the start of the war in the Soviet Union, work was carried out in this direction. We are talking about air submarines, which were also called airborne self-propelled projectiles (APS) or radio-controlled (telemechanical) submarines. It was planned that such submarines will be used in conjunction with a seaplane, from the board of which the boat will be controlled.
The development of submarines, which, according to the concept, were significantly ahead of their time, was carried out by the OstechBureau - a Special Technical Bureau for Special-Purpose Military Inventions, located in Leningrad. The specialists of this organization were engaged in the development of promising models of military equipment. The bureau was founded in 1921 and worked until 1937. The organization was led by the designer and inventor Vladimir Ivanovich Bekauri, who was known primarily for his military developments. Employees of OstechBureau managed to implement a fairly large number of interesting projects for their time. They were engaged in the creation of radio-controlled tanks and torpedo boats, worked on the creation of radio-controlled landmines, created barrage mines and torpedoes, as well as new models of radio stations and metal detectors. Many of the projects they proposed at that time were significantly ahead of the time and capabilities of the industry. Radio-controlled mini-submarines could be attributed to similar projects.
In many ways, the topic of creating small unmanned submarines even before the Great Patriotic War did not receive significant publicity for the reason that in 1937 the OstechBureau, which specialized, among other things, in the development of midget submarines, ceased to exist and was divided into three independent industry institute. At the same time, in 1937, the head of the OstechBureau and many leading specialists of the organization were arrested, in 1938 Vladimir Bekauri was shot as an "enemy of the people", posthumously rehabilitated in 1956. This is how the creator of the first radio-controlled Soviet landmines, which made such an impression on the Germans in the summer and autumn of 1941, ended his life. The first Soviet radiomine was called BEMI, after the initials of its creators Bekauri and Mitkevich. It is worth noting that in 1938, the designer OstekhBuro Fyodor Viktorovich Shchukin, who worked on the creation of the first Soviet ultra-small submarines, was also shot.
After the work on the creation of ultra-small submarines in the USSR was almost completely stopped most of the technical documentation, as well as the investigative materials were classified, they settled for a long time in the archives of the NKVD. Only in the 1980s, information about the design of various ultra-small submarines in the Soviet Union in the pre-war period began to re-open to the general public, at the same time the first articles on the creation and testing of the first Soviet midget submarines began to appear in the specialized literature.
As you already understood, in the activities of the OstechBureau, submarines occupied a prominent, but not the main place. Direct work on ultra-small submarines began in Leningrad only in 1934, when a separate group was formed as part of the first department of the OstechBureau, which was engaged in the design of submarines. The first project, which was embodied in metal, as noted above, received the designation APSS - Aero-underwater self-propelled projectile. A group of engineer K. V. Starchik worked on the creation of an unusual submarine, and Bekauri personally supervised all work on the project, and specialists from the Scientific Research Naval Institute of Communications also supervised the project.
APSS boat model
The first APSS was a classic midget submarine, its displacement did not exceed 8.5 tons, length - 10 meters, width - 1.25 meters. The underwater speed was supposed to be up to 4.5 knots, and the maximum submersion depth of the boat was limited to ten meters. Two options were considered as the main armament of the boat: either a 457-mm torpedo of the 1912 model, which was placed in an open torpedo tube at the bottom of the boat's hull, or an explosive charge, which was placed directly in its hull.
The APSS boat had an elongated cigar-like shape with two overhead keels, between which it was possible to install a single open torpedo tube. In total, the boat had 5 compartments. The first was a removable bow, it was here that it was possible to install an explosive charge with a total mass of 360 kg, the charge was driven by a proximity fuse. The second and fourth compartments were used to accommodate storage batteries (in the second - 33 cells, in the fourth - 24 cells). Also, both compartments were used to accommodate various parts of the boat's telecontrol equipment. In the fourth compartment there were also steering gears that worked on compressed air. The third compartment housed the main part of the telecontrol equipment, equalizing, ballast and torpedo replacement tanks, as well as mechanisms that were used to control the torpedo launcher. In the fifth compartment of the boat, a direct current electric motor was installed, developing a power of 8.1 kW (11 hp), as well as a propeller shaft with a propeller. The tail unit with rudders was located in the stern of the boat. In the strong keels, the designers placed four cylinders for 62 liters of compressed air each, these cylinders were used to operate the boat's automation elements, as well as to purge the tanks.
On the strong hull of the boat, antenna masts were located in the upper part, and on the upper part of the second and fifth compartments there were special portholes with headlights, which were directed upwards. They were planned to be used in order to identify and monitor the APSS at night. In addition, there was a special device in the stern, which was responsible for the release of a fluorescent composition, which has a green color, into the water. This composition was supposed to facilitate the process of escorting the boat during daylight hours. The main control mode of the ultra-small submarine was radio control during visual tracking of the APSS from the ship or the driver aircraft, hence the name aero-submarine. It was planned to control the submarine by transmitting encrypted radio signals in the long-wave range when the boat is submerged to a depth of three meters and in the VHF range when the submarine is moving on the surface.
On board the submarine there were special receivers of the DV and VHF range with decoders, they converted the incoming radio commands into direct current signals that controlled the elements of the submarine's automation. In addition, a mechanical auxiliary control was provided, there was a mechanical automatic course plotter. This mode allowed diving to a depth of 10 meters, while the boat could move along a given course for up to 5 hours.
The carrier of the aero-submarine was planned to make the ANT-22 seaplane, which was developed at the Tupolev Design Bureau. It was planned that the aircraft would be able to carry at least one APSS on an external sling. The boat's transport and suspension units were located above the second and fourth compartments, the distance between the fastening elements was almost five meters. The flight range of the ANT-22 allowed the seaplane to transfer the ultra-small submarine to the area of operation at a distance of 500-600 km from the base.
In 1935 and 1936, two ultra-small submarines were completed according to this project. They differed from each other in their bodies. One boat was made in riveted, the second - in a welded hull. Both boats reached the stage of factory tests, but they could not go further the acceptance path, they were never accepted into service, the submarines also did not reach the tests with the participation of drivers, the possibility of manual control was also provided for by the designers. In the published official reports regarding this project, it was noted that "the problem of remote control of the submarine is still far from a positive solution." Considering that it was the second half of the 1930s, there is nothing supernatural in this.
The seaplane ANT-22 in flight, it was planned to use it as a carrier of radio-controlled submarines APSS
Already in the second project of the OstechBureau to create an ultra-small submarine, the possibility of radio control from an aircraft was abandoned quite quickly. Still, the creation of radio-controlled landmines is one thing, and the development of complex underwater controlled vehicles is a completely different level of development of science and technology. Initially, the novelty also bore the name of the nuclear submarine (Aero-submarine), but later the project received a new symbol "Pygmy". The Pygmy was already a more conservative midget submarine, with a crew of four sailors on board. A team of engineers headed by F. V. Schukin was responsible for the development of the midget submarine. According to the documents that have come down to us, we can say that the "Pygmy" was a single-hull boat with a maximum displacement of about 18 tons, the length of the boat grew to 16.4 meters, the width - up to 2.62 meters. The underwater speed was supposed to be about 3 knots, surface speed - up to 5 knots. The main armament of the boat was again supposed to be 457-mm torpedoes of the 1912 model, located in open-type onboard torpedo tubes. The power plant of the boat consisted of a 24 hp diesel engine. (there was the possibility of forcing up to 36 hp), as well as a propeller electric motor, which was powered by onboard batteries.
Factory tests of the new boat, which were carried out at Oranienbaum in August 1935, were generally recognized as successful. The ultra-small Soviet boat several times independently went out into the water area of the Gulf of Finland. Already in November of the same year, by order of the People's Commissar of Defense, it was ordered to release at least 10 midget submarines, while the first six hulls were to be ready in 1936. In the same November 1935, the only built sample was transported by rail to the Crimea in Balaklava, where the OstekhBureau Sevastopol base was located, here the new boat was to pass the stage of acceptance tests. Based on the test data, it was planned to make all the necessary changes to the project of an industrial series of submarines aimed at improving the tactical and technical characteristics of the submarine and eliminating the identified shortcomings. The tests of the boat were carried out in the framework of the "Special Secrecy" regime (according to the "OS" stamp). A special department of the headquarters of the Black Sea Fleet decided that tests of an ultra-small submarine should be carried out within the Quarantine Bay and mainly at night.
Ultra-small submarine "Pygmy" captured by German troops
However, the work neither in 1936 nor in 1937 yielded any results. It was not possible to bring the midget submarine to the conditions that were necessary for the representatives of the fleet. At the same time, over several years, the resource of batteries, an electric motor and other equipment installed on board the boat was significantly reduced, and naval sailors soon became convinced of this, among whom was senior lieutenant B. A. 1st submarine brigade of the Black Sea Fleet. One of the acts of the selection committee directly stated that the living conditions of the "Pygmy" left much to be desired and were extremely difficult for the crew. Added to this were frequent technical failures. Among other things, it was noted that the magnetic compass gave an error of up to 36 degrees, the reason was its proximity to the laid electrical cable. Strong vibrations were also highlighted, which could indicate a mismatch between the electric motor and the shaft line. The diesel engine produced in a single copy for this ultra-small submarine was an experimental one, it was very hot, and besides, it smoked. Moreover, the rumble from his work could be heard at a distance of several miles from the boat.
The midget submarine "Pygmy" was not brought to the stage of acceptance and never entered service, nor was the submarine included in the fleet. In the fall of 1937, the submarine was officially declared unsuitable for acceptance or testing, after which it was dismantled and moved from Balaklava to Feodosia, where the submarine was located on the territory of the naval weapons test base. At the same time, the "Pygmy" continued to be listed by the People's Commissariat of the USSR Navy as an experimental submarine. During the Great Patriotic War, the dismantled boat turned out to be a trophy of the German troops; its photographs, taken by the invaders in early July 1942, have survived to this day. At the same time, the further fate of the submarine is unknown, what happened to her after 1942, no one knows. But one thing is known for sure, our country entered the Great Patriotic War without being armed with ultra-small submarines, and Italian mid-size submarines deployed there overland operated in the Black Sea.
