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System Of Detection Of Wake (Systema Obnaruzhenya Kilvaternogo Sleda SOKS)

A wake detection system (WKS) are special sensors that analyze the state of water near a submarine. And sometimes from this analysis it can be determined that another submarine has passed here recently - nuclear submarines leave a small footprint from the reactor, emit warm water used to cool the reactor, diesel submarines leave exhaust from a diesel engine, or a trail of bubbles, etc. That is, with a competent analysis, can not only determine that another submarine passed in this place, but can even determine the direction of its movement, speed and distance. Well, in much the same way as on modern fighters, it is determined by special thermal radars from the thermal and gas trail left by the engines of the enemy aircraft.

Such systems have been used on Soviet submarines since the late 1960s. And for a long time this caused great concern. There were several cases when Soviet submarine pursued a Western submarine for several days, and at the same time remained most of the time from it at a very respectful distance - a distance at which at that time the Western sonar could not detect Soviet submarines. At the same time, the Americans knew for sure that the Soviet acoustic systems at that time were worse than theirs, and how Soviet submarines managed not only to find their submarines at such a great distance, but also then to pursue them for a long time - Western analysts could not understand for a long time.

In the late 1980s, the USSR announced an achievement that many military experts considered impossible. The K-147 nuclear submarine secretly followed the American nuclear submarine for six days. At that time, observers from the United States believed that the USSR did not have enough technology to develop an effective sonar, at least in comparison with the capabilities of the United States and its NATO allies. As it became known from a recently declassified CIA report, Soviet submarines tracked American submarines without the use of sonar. The USSR developed other tricky means of detecting submarines.

One of the methods described in the report is the Soviet mysterious SOX - wake-track detection system. This device, installed on Russian assault submarines, tracks the wake that the submarine reserves. SOX were first installed on the K-14 in 1969. Since then, subsequent versions under code names were installed on each new generation of Soviet and Russian torpedo submarines, including those installed on modern submarines of the Shark and Ash class.

The Soviets developed not one device, but several. One of these devices could capture “activation radionuclides” - a faint trace that remains from radiation emitted by an onboard nuclear power plant. Another instrument was a gamma spectrometer, which detects traces of radioactive elements in seawater.

The report also describes how submarines leave behind a range of chemicals. Their proportions with respect to the ocean are negligible, but sophisticated equipment can detect them. And, unsurprisingly, a nuclear reactor leaves a lot of heat. According to the report, a large nuclear submarine requires "over 10,000 liters of refrigerant per minute." This water, used to remove heat from the reactor, can be 10 degrees warmer than the surrounding seawater, which changes the refractive index of the water — a change detected by the optical interference system.

The British fleet had shown continued interest in wake detection devices and guidance systems. Reports of the presence of non-acoustic detection devices on British nuclear submarines appeared in the 1980s and 1990s. In 2008, the allegedly tested SOX device was observed on the retractable guards of the British atomic multipurpose submarine S 107 Trafalgar (decommissioned in 2009).

However, it is not clear which of these inventions are theoretical and which are used in practice. Sensors cannot simply say “there was a submarine”, they only generate a stream of numerical data. Significant processing power is needed to calculate the probability of a submarine being present from the entire data set, and the report notes that in the 1970s the Soviet Union was far behind in this area.

In 1959-1966 The first exploratory studies were conducted in the interest of creating wake detection tools. As a result of the work carried out in 1963-64. The first stations for detecting the thermal wake trace of the MI-110K and MI-110R submarines were adopted by the NK. Moreover, the MI-110K station turned out to be so successful that its modernized version of the MI-110KM was installed on many NKs in the 90s. The development of these stations was carried out under the leadership of E.K. Pechnikov and B.S. Smolyansky. Under favorable hydrological conditions, these stations were successfully used in search operations. Nevertheless, the hydrological conditions affected the operation of these stations to an even greater extent than that of the GAS, and there was considerable difficulty in isolating the trace against the background of natural inhomogeneities of the medium.

Work on the creation of new, more advanced stations for detecting submarines on the wake trail was continued in the 1970s, which led to the creation of stations of new samples of the type: Kaira (1978), Bullfinch-2 (1979) , "Toucan-1" (1981) and "Ear" (1982). Further improvement of these stations was continued. As a result, the Soviet Navy received a radically new means of detecting submarines that were not in service with foreign fleets The hydrological conditions affected the operation of these stations to an even greater extent than that of the HAS, and there was considerable difficulty in isolating the trace against the background of natural inhomogeneities of the medium.

Equipment on the Project 971 boats for detecting submarines and enemy ships in the wake of the wake - SOKS (wake detection station) MNK-200-1 "Tukan". The SOKS equipment records the parameters of the movement of ships and submarines for approximately 30 minutes to several hours after the passage. It is installed on boats starting from K-322 (serial No. 513) as standard with the MNK-200-1 Tukan. The K-480 Bars submarine installed a model of the SOKS MIK-200 Tukan device with protective petals. There are no SOX devices on the K-461 and K-328 submarines (most likely during the construction of the submarine there was no equipment, it was planned to be delivered during an average repair).

The technology of search and detection of submarines on the wake trail left by a submarine is being developed by the Krylov State Scientific Center. This was announced in July 2019 by the scientific director of the center Valery Polovinkin. According to Polovinkin, the center was engaged in the development of technology for detecting submarines in their wake trail, a disturbed strip of water left by the ship’s propellers. The reason for this interest was that the wake trail remains in the water longer than other physical fields of the ship, since the acoustic noise and electromagnetic signals produced by the submarine move with it, and the wake trail still remains for some time. With the help of its detection, it is possible to find out the direction of movement of the submarine or the point where it was.

Polovinkin, of course, did not disclose the details of the ongoing research in this direction, but said that work was being done to detect the "fields of evidence" of the submarine, but not acoustic. It is known that the wake stream is an acoustic unmasking factor by which a submarine can be detected, but such noises move with the submarine and quickly fade away from the detection point.

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Page last modified: 13-09-2021 17:22:14 ZULU