Most specialized information sources, both in Russia and abroad, mention foreign electromechanical encoders. The USSR also has significant achievements in this area, but for certain reasons, we know little about this. And there is something to tell about, especially since the matter was not limited to encryption devices. So, the Special Technical Bureau (Ostechbyuro), created in 1921, three years after its foundation, began to develop the first text electromechanical encoders. Originally conceived as a branch of the Moscow Research Institute-20, Ostekhbyuro eventually became a major center of competence on the topics of mine, torpedo, diving, communications, telemechanics, and parachute technology. In particular, new items of control of radio fuses using coded signals were presented. This breakthrough was made in 1925, and a year later, the first developments in remote control of floating shells were obtained. As you can see, the theme, similar to the modern "Status-6", was founded in the pre-war period.
The head of the bureau, Vladimir Ivanovich Bekauri, in 1927 directly supervised the development of the BEMI device (Bekauri and Mitkevich), which was designed to control the explosions of landmines at a distance of about 700 km using powerful radio broadcasters. In 1931, the first models of disk encoders appeared, and in 1936 the secret encrypted communication equipment "Shirma" was tested. For the interests of the Air Force, Ostechbyuro developed a high-quality anti-jamming radio communication equipment "Izumrud", which was used to equip long-range bombers and reconnaissance aircraft. Used "Emeralds" and to communicate with the Air Force headquarters with each other. However, the most famous were the projects of radio-controlled mines, tanks, torpedoes, aircraft, as well as the further improvement of the "BEMI" theme. Such a technique came as a complete surprise to the German troops during the war - for a long time they could not understand the reasons for the inexplicable explosions deep in the rear of their own troops. Understanding came with new intelligence that described the Russians' new engineering ammunition. In the secret order of Hitler, which fell into the hands of the domestic special services in December 1941, it was said:
“The Russian troops, retreating, are using“infernal machines”against the German army, the principle of operation of which has not yet been determined; our intelligence has installed sappers-radio operators of special training in the combat units of the Red Army. All chiefs of POW camps to review the composition of Russian prisoners in order to identify specialists of this nomenclature. If prisoners of war, sappers-radio operators of special training are identified, the latter should be immediately transported by plane to Berlin. What to report on command to me personally."
One of the resonant applications of the new development was the explosion on November 14, 1941 in the basement of house No. 17 of Dzerzhinsky in Kharkov of a 350-kilogram land mine. The signal for the F-10 radio-controlled mine was sent from the Voronezh broadcasting station at 4:20 am, when the city's commandant, Major General Georg von Braun, was sleeping peacefully in his residence a few meters from the powerful land mine. By the way, von Braun was close relatives of the famous German designer, who became very popular after the war in the United States. The Germans took out several tons of such "gifts" from the cellars of occupied Kiev. Most of the government buildings, theaters, NKVD headquarters, Khreshchatyk and the Assumption Cathedral were mined. One of the Kiev workers pointed to the invaders at the Lenin Museum, from the basement of which German sappers extracted at least 1.5 tons of trinitrotoluene, which were supposed to lift the quarter into the air according to a coded radiogram. However, this helped only partially, and on September 24, 1941, Khreshchatyk and its environs nevertheless flew into the air. The mines were detonated in a predetermined sequence, destroying the field commander's office, gendarmerie, warehouses and a cinema. A month later, on October 22, a radio explosive exploded in Odessa, which was occupied by Romanian troops, destroying up to 50 generals and officers of the headquarters of the 10th Infantry Division of the 4th Romanian Army under the rubble of the NKVD building. The main target was the commander of the division, General Ion Glogojanu, who became one of the many victims of this sabotage.
F-10 object mine control unit without case
A typical Soviet radio explosive was a box 40x38x28 cm, in which an explosive radio device F-10 was located (the Germans called it Apparat F10), and the charge power could vary within wide limits. Each such tab was accompanied by a radio antenna 30 meters long, which was usually buried. This became the Achilles heel of the domestic development - the Germans simply dug in a suspicious area from all sides with a ditch of 50-70 cm and often ran into the receiving antenna. The eight-lamp radio was powered by a standard rechargeable battery, the capacity of which was usually enough to operate in reception mode from 4 to 40 days. In addition, the complete set of the charge included a radio signal decoder "Apparatus A". The blasting control unit could be located both in the immediate vicinity of the charge, and at a distance of up to 50 meters, connected to the explosives by an electric explosive line. Transmitting equipment not lower than a divisional link could undermine such a bookmark. One of these was the radio station of the operational level of the PAT, which has an output power of one kilowatt and a range of up to 600 km. Also in this company stands out a radio station RAO-KV with a power of 400-500 W with a range of about 300 km, and the "weakest" RSB-F for 40-50 W with a range of up to 30 km. These radio stations operated in the range of 25-120 meters (short and medium waves). The accumulators of the battery were enough for no more than four days of constant work - large losses affected the heating of the radio tubes. For this reason, a clock mechanism was introduced into the design of the mines, which periodically turned off the power. In the operating mode, when the mine is in a combat position for 150 seconds, and "resting" for 150 seconds, the standby time is 20 days. In position 5 (5 minutes of work and 5 minutes of rest), the work period increases to the maximum possible 40 days. Naturally, taking into account the nature of the clockwork operation, the coded radio signal for the explosion must be supplied for at least 1 minute (continuous operation), 6 minutes (in 150 seconds mode) and 10 minutes (in the rhythm of 5 minutes on - 5 minutes off). The F-10 mine could be set to self-detonate from a delayed-action fuse - for 10, 16, 35, 60 or even 120 days. For the reliability of the charge operation, the instruction recommended installing 2-3 mines on the object at once. The Finnish sapper Jukka Lainen wrote about the principle of initiation of the explosion: "The fuse operates on the principle of three consecutive tuning forks, which are forced to vibrate using a triple audio frequency signal (pause tunes of Kharkov and Minsk civil broadcasting radio stations were used)." For the first time, the Red Army tested engineering ammunition of a new design on June 12, 1942 on the Northern Front, when the abandoned settlement of Strugi Krasnye in the Pskov region was blown up. Three mines exploded at once, 250 kilograms of TNT in each - a detonation signal was sent from a distance of 150 km. To fix the consequences of the action, two days later, scouts flew over the village, who discovered three huge craters and piles of destroyed buildings.
The Germans are taking out the F-10 radio bombs from the Kiev Museum. V. I. Lenin, 1941
At the end of 1941, the Germans realized what they were dealing with in their own skin, and organized a campaign to find and neutralize mines of the F-10 type. To begin with, important buildings in the occupied territory were listened to with special acoustic equipment Elektro-Akustik, which made it possible to catch the ticking of a clock mechanism at a distance of up to 6 meters. Also, the Germans received instructions for a radio mine, which made it possible to organize jamming by a sapper company, consisting of 62 people, armed with several 1.5-kilowatt transmitters and receivers. It is noteworthy that a typical trick of Soviet special-purpose sappers who worked with the F-10 was the installation of a conventional push-type mine over the radio blast bomb. Obviously, this effectively lulled the vigilance of the Germans - in Kharkov, out of 315 F-10 mines installed by the retreating Soviet units, the Germans were able to neutralize only 37.
Receiver and battery of radio explosives. The bottom photo shows the numbers 6909-XXXIV. There are no assumptions about the first "Arab" number, but "Roman digitization", according to the Germans, means a conventional number of the length to which the mine is tuned. So, XXXIV can talk about a frequency of 412, 8-428, 6 kilohertz. If the number on the box was greater than XVIII, it meant that the "hell machine" was tuned for special long-range control and had a high sensitivity.
In the memoirs of Marshal of the Engineering Troops V. K. Kharchenko, one can find the following words:
“Radio-controlled Soviet mines inflicted considerable losses on the Nazis. But that was not the only point. F-10 devices, together with conventional time mines, created nervousness in the enemy's camp and made it difficult to use and restore important objects. They forced the enemy to waste time so precious for our troops in the harsh summer and autumn of 1941”.
Until 1943, the Red Army "nightmares" the rear of the occupiers with radiomines, and their creator, V. I. Bekauri, did not live to see the triumph of his own brainchild - in 1938 he was shot on charges of spying for Germany. All charges were dropped only in 1956.
At the end of the story, it is worth citing the words of General Helmut Weidling about domestic radio explosives, which were recorded in Berlin in May 1945: "We did not have the appropriate equipment, and as for radio explosives, your engineers were far ahead of ours …"
