The night of November 14, 1941 was already turning into early morning, when a deafening explosion shook Dzerzhinsky Street in Kharkov and the surrounding areas of the city. The mansion, located at 17 Dzerzhinsky Street, flew into the air. Before the war, a detached one-story residential building was built for the first secretary of the Communist Party of Ukraine Stanislav Kosior, and after the transfer of the capital from Kharkov to Kiev, the secretaries of the Kharkov regional committee lived in the house. After the occupation of the city, this mansion was chosen by the commander of the German 68th Infantry Division, Major General Georg Braun.
As a result of the detonation of a 350-kilogram radio-controlled land mine, the mansion was destroyed. Under its rubble, 13 German soldiers and officers died, including the commander of the 68th Infantry Division and the military commandant of Kharkov, Major General Georg Brown (he was posthumously awarded the rank of Lieutenant General), two officers of his staff, as well as 4 non-commissioned officers - an officer and 6 privates. The head of the reconnaissance department of the 68th Infantry Division, an interpreter and a sergeant major were seriously injured. The explosion on Dzerzhinsky Street in Kharkov was one of the detonations of powerful radio bombs, which were previously installed by Soviet sapper units before the city was surrendered to the enemy. On the same night, with the help of a pre-laid mine, the support of the Kholodnogorsky viaduct was undermined.
The Germans guessed that mines would be waiting for them in Kharkov from the sad experience of Kiev. And on October 22, in the building of the NKVD, located on Marazlievskaya Street, in Odessa, occupied by the Romanian-German troops, an explosion of a radio-controlled mine, set by Soviet sappers even before the surrender of the city, took place. As a result of a powerful explosion, the building partially collapsed, burying 67 people, including 16 officers, under the rubble. The building housed the headquarters of the 10th Infantry Division of the 4th Romanian Army, as well as the city's military commandant's office. The explosion killed the commander of the 10th Infantry Division and the military commandant of the city, Romanian General Ion Glogojanu.
German self-propelled gun StuG III shoots into the corner of a house on Moskovsky Prospekt in Kharkov, 1941
Knowing what awaited them, the Germans were able to neutralize most of the radio mines installed in Kharkov. For example, when ditching the district headquarters building with a ditch, the Germans found a radio bomb antenna, by which they were able to determine its location. While trying to defuse an explosive device, a German sapper was killed, who was blown up by a booby-trap. At the same time, the Germans managed to extract the mine charge (600 kg). On October 28, 1941, the Germans discovered and defused a mine in the Usovsky viaduct, and the next day they found and defused a radio mine in the railway bridge.
The house, located at 17 Dzerzhinsky Street, was also checked by German sappers, who discovered in the basement of the building under a pile of coal a huge time bomb with 600 kg of ammonal. Such a successful find completely lulls their vigilance, and it never occurred to them that such a mine could be a trick. Directly below it, a little deeper, was another mine, this time an F-10 with 350 kg of explosives, it was she who exploded in the basement of the house after Major General Georg Brown drove into it on November 13 with his headquarters.
Work on the creation of radio bombs in the USSR began long before the war. They began to be created in Ostechbyuro, which was founded back in 1927. The work was supervised by a specialist in explosions at a distance, Vladimir Bekauri, and Academician Vladimir Mitkevich also made a great contribution to the creation of Soviet radio mines. The tests carried out and the obtained tactical and technical characteristics of the radio mines made a pleasant impression on the military, so already in 1930 it was decided to deploy the production of radio mines, originally designated "Bemi" (derived from the name Bekauri - Mitkevich). Already in 1932, the Red Army had units that were armed with different types of radio-controlled landmines, which in those years were designated as TOS - a technique of special secrecy.
The control unit of the F-10 radio mine, connected to a battery, in the foreground, an extracted decoder
Before World War II, a new object mine began to arrive in the sapper units of the Red Army, which consisted of an F-10 radio device and a charge, the power of which could change in a wide range of values. Externally, the radio minus was a metal box 40x38x28 centimeters - a control unit, an eight-lamp radio receiver, a signal decoder. The weight of such a box, which in turn was placed in a rubber bag, was approximately 35 kg. The box could be installed inside the mined object where it was most convenient, as the Finns noted, it could be installed at a depth of 2.5 meters. The mine also came with a 30-meter radio antenna. The eight-lamp radio receiver of the mine was powered by a battery (the battery and the control unit were placed in boxes of the same dimension), to which it was connected using a power cable. Depending on the operating mode of the radio-minus, it could wait for a signal to detonate from 4 to 40 days.
The F-10 object radio-controlled mine was intended to destroy by detonating the most important industrial, military and political facilities, as well as key infrastructure. It was about objects, the decision on the destruction of which could not be taken in the usual way, neither at the moment the Soviet troops left the area, nor later, and which were subject to destruction only when special circumstances occurred.
Such objects included large bridges on highways and railways; viaducts; tunnels; dams; passages under overpasses where detour is impossible or extremely difficult; railway junctions; hydraulic structures; oil depots, pumping stations; airfield infrastructure: hangars, flight control points, repair shops, fuel tanks; electrical power units of large power plants, industrial facilities; mines; telephone and radio communication units; socially significant buildings that are suitable for the deployment of headquarters and institutions of enemy armies, as well as use as barracks and commandant's offices.
F-10 radio mines control unit without housing
Structurally, the mine was a control unit that could receive and decode the signals received by radio, issuing an electric pulse capable of detonating up to three electric detonators, and using a special intermediate splitter block - up to 36 electric detonators. The mass of explosives in such a radio explosive could vary depending on the nature and size of the mined object and could range from several tens of kilograms to several tons (according to the experience of use). The control unit could be located both with the charge (charges), and at a distance of up to 50 meters from them. At the same time, each of the three charges had its own electric explosive line.
At a distance from 0 to 40 meters from the F-10 there was a wire antenna with a length of at least 30 meters. The direction and placement of the antenna were determined by the conditions for the passage of radio waves, however, in the general case, it could be buried in the ground to a depth of 50-80 cm, placed in water to a depth of 50 cm, or embedded in walls to a depth of no more than 6 cm. The antenna was connected to the radiomina itself using a feeder up to 40 meters long. Three two-core cables of an electric explosive circuit emerged from the F-10 apparatus, the length of these cables could be up to 50 meters. In this case, it was desirable that the length of all three electric explosive circuits was approximately equal in order to prevent a large difference in the electrical resistance of the branches. Directly to the ends of the cable were attached electric detonators inserted into explosive charges, which turned the device into a formidable radio-controlled land mine of enormous power.
Additionally, the radiomina could be equipped with a self-destruct device using a delayed-action fuse (up to 120 days), an hourly ten-day closure, an hourly thirty-five-day closure, an hourly fuse ChMV-16 (up to 16 days), an hourly fuse ChMV-60 (up to 60 days). However, the sounds of such watch movements were a significant unmasking factor for mines. With the naked ear, one could clearly distinguish the ticking of a clock of a mine placed in the ground from a distance of 5-10 cm from the ground, in brickwork - from 20-30 cm. The clicks of the clock winding could be heard from 15-30 cm and 60-90 cm, respectively. When the Germans used special listening equipment, which was produced by the Elektro-Akustik company, the ticking of the clock was caught from a distance of 2.5 to 6 meters, and the clicks of the winding of the clock - from 6-8 meters.
German soldiers in front of the extracted F-10 radio mines and boxes with explosives
As radio transmitters, which were used to initiate a controlled explosion of a radio explosive, military radio stations of the divisional, corps or army level could be used. According to official Soviet information, on June 22, 1941, the RKKA had radio stations of the operational level of the RAT, with an output power of 1 kW and a communication range of about 600 km; RAO-KV radio stations with an output power of 400-500 W and a communication range of up to 300 km; RSB-F radio stations with an output power of 40-50 W and a communication range of up to 30 km. All of the above radio stations operated in the wavelength range from 25 to 120 meters, that is, in the short and medium range of radio waves. For example, a signal to detonate a radio explosive in Kharkov was sent from the Voronezh broadcasting station, which was located more than 550 kilometers from the city.
For the first time in world history, the Red Army used the existing radio explosives in service on July 12, 1941. Three radio-controlled landmines with a capacity of 250 kg of TNT each exploded in the village of Strugi Krasnye in the Pskov region. The radio mines were installed by the Red Army soldiers of a special mining company and detonated on a signal from a radio station located 150 km from the place of laying, after the occupation of the village by enemy troops. Two days later, aerial photography carried out by the pilots confirmed that in the place of the buildings in which the radio bombs were installed, funnels from explosions and heaps of ruins remained.
The first truly large-scale mining using the F-10 radio mines was the mining of Vyborg, where 25 radio explosives were installed, which contained from 120 to 4500 kg of TNT. Of these, 17 were blown up at 12 city objects, another 8 by the Finnish military was able to neutralize and neutralize, when it became clear that the incoming radio signal led to the explosion of mines. The mines found were sent to Helsinki for study, where specialists studied them with great interest. Already by September 2, 1941 (the Finns entered Vyborg on August 29), the corresponding instructions were issued, which contained the rules for handling and neutralizing Soviet-made radio mines. In particular, it was pointed out that pre-war pause musical melodies of Minsk and Kharkov broadcast radio stations were used as radio signals (these melodies filled the radio air between broadcasts).
Khreshchatyk in Kiev after explosions and fires at the end of September 1941
To receive the control signal, the radio-mine antenna had to be laid in a horizontal or close position and always in the direction from which the signal for detonation would come. It was not hard to guess that in all cases the antenna was directed in a direction approximately to the east. That is why a very effective way of detecting installed radio mines was to dig a ditch about a meter deep around suspicious objects. This made it possible to detect a thirty-meter antenna, which was buried at a depth of 50-80 cm near the object. Both the Finns and later the Germans made extensive use of prisoners of war for this operation. The Finns quickly shared the information they received in Vyborg with the Germans. Perhaps this information allowed the Germans to quickly and correctly organize the fight against Soviet radio-controlled mines. In Kharkov, the Germans managed to prevent the explosions of most of the radio bombs installed in the city.
It should be noted that it was in Kharkov and the regions around the city that the use of object mines equipped with delayed action fuses gave significantly better results. For example, of the 315 object mines that were placed on the railway and railway facilities by the soldiers of the 5th and 27th railway brigades, the Germans managed to find only 37, and they were able to defuse only 14, and they had to detonate 23 on the spot. The rest of the mines worked for their targets.
The very idea of controlling the detonation of mines with the help of radio signals has justified itself, proving in practice the effectiveness of this method. However, the widespread use of such mines was only possible until the moment when the enemy got his hands on working samples, instructions and a description of the principles of their work. By the middle to the end of the fall of 1941, such mines ceased to be a surprise for the Nazis and their allies. At the same time, the experience of combat use showed that radio mines have a serious drawback - they can be simply and reliably blocked, and the limited duration of their combat work was also a disadvantage. These mines had limited application possibilities. Firstly, their effective combat use was possible as rarely as the enemy deems it inexpedient to divert the radio equipment at his disposal for constant electronic reconnaissance and interception. Secondly, the short period of operation of the power supplies of radio explosives (no more than 40 days) significantly limited the use of such devices in time.
