Demagnetization. Ships will be demagnetized with one button Protecting ships from magnetic mines
Hydroacoustic detection of submarines
The physical field of the ship- a region of space adjacent to the ship's hull, in which the physical properties of the ship as a material object are manifested. These physical properties, in turn, affect the distortion of the corresponding physical field of the World Ocean and adjacent airspace.
Ship Physical Field Types
Tasks solved by the hydroacoustic complex of a submarine.
The physical fields of ships according to the location of radiation sources are divided into primary (intrinsic) and secondary (caused).
The primary (intrinsic) fields of ships are fields whose radiation sources are located directly on the ship itself or in a relatively thin layer of water surrounding its hull.
The secondary (evoked) field of the ship is the reflected (distorted) field of the ship, the radiation sources of which are located outside the ship (in space, on another ship, etc.).
Fields that are artificial in nature, i.e. formed with the help of special devices (radio, sonar stations, optical devices) are called active physical fields.
The fields that are naturally created by the ship as a whole as a constructive structure are called passive physical fields of the ship.
According to the functional dependence of the parameters of physical fields on time, they can also be subdivided into static and dynamic fields.
Static fields are considered to be such physical fields, the intensity (level or power) of sources of which remains constant during the time of impact of the fields on the non-contact system.
Dynamic (time-variable) physical fields are such fields, the intensity of the sources of which changes during the time of the field impact on the non-contact system.
The main types of physical fields of the ship
Currently, modern science identifies more than 30 different physical fields of the ship. The degree of application of the properties of physical fields in the design of technical means of detection, means of tracking ships, as well as in non-contact weapon systems is different. At the moment, the most important physical fields of ships and submarines, on the basis of knowledge about which special devices are being developed, are: acoustic, hydroacoustic, magnetic, electromagnetic, electrical, thermal, hydrodynamic, gravitational.
Taking into account the development of various areas of physics and instrumentation, new physical fields of marine objects are constantly being determined, for example, research is being carried out in the field of optical, radiation physical fields.
The main task that engineers who study the properties of physical fields solve is to search for and detect enemy ships and submarines, target them with combat weapons (torpedoes, mines, missiles, etc.), as well as detonate their proximity fuses. During the Second World War, mines with electromagnetic, acoustic, hydrodynamic and combined fuses were widely used, and hydroacoustic equipment for detecting submarines was also often used.
Acoustic field of the ship
Scheme of operation of hydroacoustic stations of a surface ship:
1 - echo sounder transducer; 2 - hydroacoustic post; 3 - sonar converter; 4 - discovered mine; 5 - detected submarine.
Acoustic field of the ship- a region of space in which acoustic waves are distributed, formed by the ship itself or reflected from the surface of its hull.
Any ship in motion serves as an emitter of the most diverse acoustic vibrations in terms of value and nature, the complex effect of which on the surrounding aquatic environment creates quite intense underwater noise in the range from infra- to ultrasonic frequencies. This phenomenon is also called the primary acoustic field of the ship. The nature of the radiation of the primary field and its propagation are determined, as a rule, by the following parameters of the ship: displacement, contours (streamlined shape) of the hull and speed of the ship, the type of main and auxiliary mechanisms.
The flow of water when bypassing the ship's hull determines the hydrodynamic component of the acoustic field. The main and auxiliary mechanisms of the ship determine the vibration component, the propellers determine the cavitation component (cavitation on the propeller is the formation of discharged gas cavities on its rapidly rotating blades in the aquatic environment, the subsequent compression of which sharply increases the noise).
As a result, the ship's primary hydroacoustic field (HAFC) is a set of fields superimposed on each other created by various sources, the main of which are:
1. Noises created by propellers (screws) during their rotation. The underwater noise of the ship from the work of the propellers is divided into the following components:
Noise propeller rotation,
swirling noise,
Vibration noise of the edges of the propeller blades ("singing"),
cavitation noise.
2. Noises emitted by the ship's hull on the move and in the parking lot as a result of its vibration from the operation of the mechanisms.
3. Noises created by the flow of water around the ship's hull during its movement.
The level of underwater noise also depends on the speed of the ship, as well as on the depth of immersion (for submarines). If the ship is moving at a speed above the critical. then in this case, the process of intense noise generation begins.
During the operation of the ship, as the main components wear out, its noise may change. When the technical resource of ship mechanisms is exhausted, they are misaligned, unbalanced and vibration increases. Vibrational energy of worn mechanisms provokes. in turn, the vibrations of the hull, which leads to disturbances in the adjacent water surface.
Indicator pictures of GAK MGK-400EM. Noise direction finding mode
The vibrations of the mechanisms are transmitted to the hull mainly through: support connections of the mechanisms with the hull (foundations); non-supporting connections of mechanisms with the body (pipelines, water pipes, cables); through the air in the compartments and rooms of the NK.
The ship's hull, by itself, is capable of reflecting acoustic waves emitted by some other source. This radiation, when reflected from the hull, turns into a secondary acoustic field of the ship and can be detected by the receiving device. The use of a secondary acoustic field allows not only to determine the direction of the ship, but also allows you to calculate the distance to it by measuring the signal propagation time (the speed of sound in water is 1500 m/s). Additionally, the speed of sound propagation in water is affected by its physical state (salinity, which increases with temperature, and hydrostatic pressure).
Submarine attack based on ship's false acoustic field
The main ways to reduce the acoustic field of the ship are: reducing the noise of propellers (selecting the shape of the blades, the speed of the propeller, increasing the number of blades), reducing the noise of the mechanisms and the hull (soundproof cushioning, acoustic coatings, sound-absorbing foundations).
Indicator pictures of GAK MGK-400EM. LOFAR mode
Hydroacoustic complex "Skat" of the nuclear submarine "Pike"
The noise of a ship affects not only its stealth from various means of detection and the degree of protection from the mine and torpedo armament of a potential enemy, but also affects the operating conditions of its own sonar detection and target designation means, interfering with the operation of these devices.
Noise is of great importance for the invisibility of submarines (submarines), since it is it that largely determines this survival parameter. Therefore, in submarines, noise control and its reduction is one of the main tasks of all personnel.
The main measures to ensure acoustic protection of the ship:
Improvement of vibroacoustic characteristics of mechanisms;
Removal of mechanisms from the structures of the outer hull emitting underwater noise by installing them on decks, platforms and bulkheads;
Vibration isolation of mechanisms and systems from the main body with the help of soundproof shock absorbers, flexible inserts, couplings, shock-absorbing pipeline hangers and special noise-protective foundations;
Vibration damping and soundproofing of sound vibrations of foundation and hull structures, piping systems using soundproof and vibration-damping coatings;
Sound insulation and sound absorption of airborne noise of mechanisms through the use of coatings, casings, screens, silencers in air ducts;
Application of hydrodynamic noise silencers in seawater systems.
Separately, cavitation noise is reduced by the following works:
Use of low-noise propellers;
Use of low speed propellers;
Increasing the number of blades;
Balancing propeller and shaft line.
The combination of engineering developments, as well as the corresponding actions of the personnel, can seriously reduce the level of the ship's hydroacoustic field.
Thermal (infrared) field of the ship
Thermal field of the ship
thermal field- the field that appears when the ship emits infrared rays. The most powerful sources of radiation from thermal fields are: chimneys and gas flares from the ship's power plant; hull and superstructures in the area of the engine room; torches of fire during artillery firing and rocket launching. When using infrared equipment, the thermal field makes it possible to detect a ship at a sufficiently large distance.
The main sources of the ship's thermal field (infrared radiation) are:
Surfaces of the above-water part of the hull, superstructures, decks, casings of chimneys;
Surfaces of gas ducts and exhaust gas devices;
Gas torch;
Surfaces of ship structures (masts, antennas, decks, etc.) located in the zone of action of a gas torch, gas jets of rockets and aircraft during launch;
Burun and the wake of the ship.
The ship in the lens of the thermal imager
The detection of surface ships and submarines by their thermal field and the issuance of target designation to weapons is carried out using special heat direction finding equipment. Such equipment is usually installed on surface ships and submarines, aircraft, satellites, coastal posts.
Additionally, various types of missiles and torpedoes are also supplied with thermal (infrared) homing devices. Modern thermal homing devices make it possible to capture a target at a distance of up to 30 km.
The main technical means of thermal protection of ships:
Exhaust gas coolers of a ship power plant (mixing chamber, outer casing, louvered air intake windows, nozzles, water injection systems, etc.);
Heat recovery circuits (TUK) of a ship power plant;
Onboard (surface and underwater) and stern gas exhaust devices;
Shields of infrared radiation from the internal and external surfaces of gas ducts (double-layer shields, profile screens with water or air cooling, shielding bodies, etc.);
Universal water protection system;
Coatings for the ship's hull and superstructures, including paintwork, with reduced emissivity;
Thermal insulation of high-temperature ship premises.
The heat visibility of a surface ship can also be reduced by using the following tactics:
Application of masking effects of fog, rain and snow;
Application as a background of objects and phenomena with powerful infrared radiation;
The use of bow heading angles in relation to the carrier of heat direction finding equipment.
For submarines, thermal visibility decreases with increasing depth of their immersion.
Hydrodynamic field of the ship
Hydrodynamic field of the ship
In the region of the extremities, zones of increased pressure are formed, and in the middle part along the length of the hull, an area of reduced pressure is formed.
Hydrodynamic field- the field arising as a result of the movement of the ship, due to a change in the hydrostatic pressure of water under the ship's hull. According to the physical essence of the hydrodynamic field, it is a perturbation by a moving ship of the natural hydrodynamic field of the World Ocean.
If in every place of the World Ocean the parameters of its hydrodynamic field are mainly due to random phenomena, which are very difficult to take into account in advance, then a moving ship introduces not random, but quite natural changes in these parameters, which can be taken into account with the accuracy necessary for practice.
When the ship moves in water, the liquid particles located at certain distances from its hull come into a state of perturbed motion. When these particles move, the value of the hydrostatic pressure changes in the place where the ship is moving, i.e. a hydrodynamic field of a ship of certain parameters is formed.
When a submarine moves under water, the area of pressure change extends to the surface of the water in the same way as to the ground. If the submarine moves at a shallow depth, then a well-marked hydrodynamic wave wake can be visually fixed on the water surface.
The properties of the ship's hydrodynamic field are often used in the development of non-contact hydrodynamic fuses for bottom mines.
To date, significant effective means of hydrodynamic protection of the ship have not been developed. Partial reduction of the hydrodynamic field is achieved by calculating the balance between the optimal displacement of the ship and the shape of its hull. The main tactical method of hydrodynamic protection of the ship is the choice of a safe speed. A safe speed is one at which either the magnitude of the pressure drop under the ship does not exceed the set threshold for triggering the mine fuse, or the time the fuse is exposed to the low pressure area is less than that set in the fuse.
There are special schedules for safe ship speeds and rules for use, which are given in a special instruction for choosing safe ship speeds when navigating in areas where hydrodynamic mines can be laid.
Ship's electromagnetic field- the field of time-varying electric currents created by the ship in the surrounding space. The main emitters of the electromagnetic field of the ship are: alternating galvanic currents in the "propeller-hull" circuit, vibration of the ferromagnetic masses of the hull in the Earth's magnetic field, the operation of the ship's electrical equipment. The electromagnetic field has a pronounced maximum in the region of the propellers, and at a distance of several tens of meters from the hull it practically fades.
The electromagnetic protection of the ship is carried out by choosing a non-metallic material for propellers:
Applications for them of non-conductive coatings, application of contact-brush devices on the shafting;
Shunting variable oil clearance resistance in bearings;
Maintaining the insulation resistance of the shaft from the body within the established norms.
On ships with non-magnetic and low-magnetic hulls, the main attention is paid to the issues of reducing the electromagnetic field of electrical equipment elements.
ship's magnetic field
ship's magnetic field
ship's magnetic field- a region of space within which changes in the Earth's magnetic field are detected due to the presence or movement of a magnetized ship.
The ship's magnetic field is the resulting value of the superposition of several fields: constant (static) and inductive (dynamic) magnetization.
Permanent magnetization is formed near the ship mainly during the construction period under the influence of the earth's magnetic field, and depends on:
The location of the ship relative to the direction and magnitude of the lines of the Earth's magnetic field at the construction site;
The magnetic properties of the materials themselves from which the ship is built (residual magnetization);
The ratio of the main dimensions of the ship, the distribution and shape of the iron masses on the ship;
Technologies used to build the ship (number of riveted and welded joints).
To quantitatively characterize the magnetic field, a special physical quantity is used - the magnetic field strength H.
Another physical quantity that primarily determines the magnetic properties of a material is the intensity of magnetization I. In addition, there are concepts of residual magnetization and inductive magnetization.
The use of low-magnetic and non-magnetic materials in the construction of a ship makes it possible to significantly reduce its magnetic field. Therefore, in the construction of special ships (minesweepers, minelayers), materials such as fiberglass, plastics, aluminum alloys, etc. are widely used, and in the construction of some projects of nuclear submarines, titanium and its alloys are used, which, along with high strength, is a low-magnetic material . However, the strength and other mechanical and economic characteristics of low-magnetic materials make it possible to use them in the construction of warships within limited limits. There are also highly magnetic materials, these include: iron, nickel, cobalt and some alloys. Substances that can be strongly magnetized are called ferromagnets.
The principle of operation of a magnetic mine
In addition, even if the hull structures of ships are made of low-magnetic materials, then a number of ship mechanisms remain made of ferromagnetic metals, which also create a magnetic field. Therefore, for ships, the level of their magnetic field is periodically monitored and, if the permissible value is exceeded, the hull is demagnetized. There is winding and winding demagnetization. The first is carried out with the help of special ships or at windingless demagnetization stations, the second provides for the presence on the ship itself of stationary wires (cables) and special DC generators, which, together with the control and monitoring equipment, constitute the demagnetizing device of the ship.
The ship's magnetic field (MPC) is widely used in proximity fuses for mine and torpedo weapons, as well as in stationary and aviation systems for magnetometric detection of submarines.
An example of experiments to reduce the magnetic field is the so-called Philadelphia experiment, which to this day remains the subject of many speculations, since documentary evidence of the result of the experiment has not been publicly made public.
Ship's electric field
Ship's electric field
Ship's electric field(EPK) - a region of space in which direct electric currents flow.
The main reasons for the formation of the electric field of the ship are:
Electrochemical processes occurring between ship parts made of dissimilar metals and located in the underwater part of the hull (propellers and shafts, steering gear, bottom-outboard fittings, hull cathodic and protective protection systems, etc.).
Processes generated by the phenomenon of electromagnetic induction, the essence of which lies in the fact that the ship's hull during its movement crosses the lines of force of the Earth's magnetic field, as a result of which electric currents arise in the hull and the masses of water adjacent to it. Similar currents are formed in ship propellers during their rotation. As a rule, the ship's hull is made of steel, propellers and bottom fittings are made of bronze or brass, sonar fairings are made of stainless steel, and corrosion protectors are made of zinc. As a result, galvanic vapors are formed in the underwater part of the ship and stationary electric currents arise in sea water, as in an electrolyte.
Processes associated with the leakage of currents of ship's electrical equipment to the ship's hull and into the water.
The main reason for the formation of EPC are electrochemical processes between dissimilar metals. About 99% of the maximum value of the EIC is accounted for by electrochemical processes. Therefore, to reduce the level of EPA seek to eliminate this cause.
The ship's electric field greatly exceeds the natural electric field of the World Ocean, which allows it to be used in the development of non-contact naval weapons and submarine detection tools.
Reducing the level of the electric field is achieved: - by using non-metallic materials in the manufacture of the body and parts in contact with sea water;
By selecting metals according to the proximity of the values of their electrode potentials for the body and parts in contact with sea water;
By shielding EPA sources;
By disconnecting the internal electrical circuit of EPC sources;
Through the use of special coatings of EPC sources with electrically insulating materials.
Areas of use
The physical fields of the ship are currently widely used in three areas:
In non-contact systems of various types of weapons;
In detection and classification systems;
in homing systems.
Links and sources
Literature
1. Sverdlin G. M. Hydroacoustic transducers and antennas.. - Leningrad: Shipbuilding, 1980.
2. Urick R.J. (Robert J. Urick). Fundamentals of hydroacoustics (Principles of Underwater Sound).. - Leningrad: Shipbuilding, 1978.
3. Yakovlev A.N. Short range sonar.. - Leningrad: Shipbuilding, 1983.
In the future, we always strived to ensure that all RRFs were self-propelled, but fate sometimes pleased ... at the behest of the senior authorities to throw us non-self-propelled barges with a displacement of up to 450 tons. special rooms for work and to comfortably accommodate the team. However, all these charms paled before the shortcomings associated with the lack of their own course.
By the nature of its activity, the SBR was an operational technical means of ensuring the activities of the warships of the fleet. The experience of the war years and later showed that the RRF should, without the help of tugboats, on their own, make transitions not only within the same port, but also between different ports or places of permanent or temporary basing of ship formations, areas of trawling, exercises and preparation of operations. So, for example, during the minesweeping of magnetic and induction mines in the Sea of Azov, where more than 100 boat electromagnetic minesweepers were simultaneously working, it was necessary to systematically measure the magnetic fields of the entire armada, and in case of strong shaking of the hulls from the explosions of the etched mines, to perform windless demagnetization. Due to the large amount of work, minesweepers worked almost around the clock, "without taking the trawl out of the water." Breaks to move to the RRF base port and measure magnetic fields were highly undesirable. Therefore, in order to conserve the motor resources of the minesweepers and their more efficient use, the trawling brigade or detachment was attached to the SBR, which served them and wandered along with them from one trawling area to another. There were other cases when it was necessary to maneuver with technical means to perform a large amount of work in a short time, for example, in preparation for landing operations or exercises.
The principle of windless demagnetization of ships is based on the following provisions of ferromagnetism.
It is known that any ferromagnetic body placed in an external magnetic field receives inductive and permanent or residual magnetization. The magnetic field near the body from inductive magnetization in a weak external field, which is the terrestrial magnetic field, depends on its magnitude and direction, i.e., on the geomagnetic latitude of navigation and the course of the ship. The magnetic field from permanent magnetization results from the phenomenon of hysteresis. The value of residual magnetization greatly increases if a constant magnetic field and elastic stresses (vibrations, shocks, etc.) or constant and alternating magnetic fields act simultaneously on a ferromagnetic body.
Under natural terrestrial conditions, the directions (signs) of the magnetic fields of inductive and permanent magnetizations coincide and the total magnetic field, including its vertical component, is summed up.
In order to reduce the vertical component of the ship's magnetic field, it is obviously necessary to magnetize the ship in such a way that the vertical component of the permanent magnetization strength is equal in magnitude and opposite in sign to the vertical component of the ship's inductive magnetization. Strictly speaking, it was not demagnetization, but magnetization by the non-winding method of the ferromagnetic masses of the ship.
To do this, along the contour of the ship, approximately at the level of the waterline, a thick flexible cable was hung on the hemp ends. When a current is passed through it, the sides of the ship are magnetized. Often, to enhance the effect, the wide belts of the sides of the ship were magnetized by moving (rubbing) the cable in the vertical direction at the moment the current was passed. If the current strength is very high, then the cable is attracted to the board so strongly that there is not enough strength to move it manually. On large merchant ships, cranes, winches, etc. were used to move the cable at the time the current was passed.
The elimination of the permanent longitudinal and transverse magnetization of the ship by the non-winding method was carried out in the truest sense of the word, i.e., by demagnetization.
The method of windless demagnetization of ships with its modifications, with proper work experience, turned out to be quite flexible and made it possible to protect submarines, auxiliary vessels and small ships from enemy magnetic and induction mines with a small amount of technical means. However, it provided satisfactory protection only in the geomagnetic zone in which demagnetization was carried out. In other zones, the inductive magnetization changes in proportion to the change in the vertical component of the Earth's magnetic field, and the permanent magnetization changes slowly, over many months. Under the influence of various external factors, elastic stresses, stormy weather, deep-sea diving (for submarines), as well as close explosions of aerial bombs and other concussions, the permanent magnetization increases many times over.
In addition, it also depends on the prehistory, that is, on how much and how the ship was previously magnetized. Therefore, the results of studying the influence of these phenomena on the change in the magnetic fields of ships had to be strictly systematized.
For this purpose, the Criminal Code of the Navy developed special forms of protocols for windless demagnetization and control measurements of the magnetic fields of ships equipped with demagnetizers and equipment for their adjustment. In addition, forms of passports were developed that are issued to ships and filled in at the RRF during each next demagnetization. We received such documents from the flagship mechanic of the headquarters of the Black Sea Fleet on October 7, 1941.
The introduction of protocols and passports for the demagnetization of ships greatly facilitated the implementation of this process. It made it possible to accumulate experience in carrying out work, to study the influence of various factors on the change in the magnetic fields of ships, and, finally, was of great organizational importance. Ships that did not pass the next demagnetization within the prescribed period were not allowed to go to sea. And no one in the Black Sea Fleet violated this provision.
The operation to demagnetize the ships, according to the regulations, was carried out when the ship had already received the ammunition and all the cargo with which it would sail, i.e. it was the penultimate one (the last was the elimination of the deviation of the magnetic compasses) when preparing the ship for the campaign, and, as As a rule, there was very little time left for its implementation. This led to the fact that the demagnetization of the ship often had to be carried out at night, with complete blackout.
At the end of September 1941, by decision of the headquarters of the Black Sea Fleet, in the area of Troitskaya Bay, the Mine and Torpedo Department of the Black Sea Fleet equipped a test site, where, along with other devices, a contactor from a disarmed German magnetic mine was installed. The wires from it were brought ashore, to the laboratory. It became possible not only to check the quality of demagnetization of ships at this test site, but also to demonstrate it publicly. If the ship was demagnetized well, then when it passed along the stand above the contactor, no signals arose on the shore, and if the demagnetization was unsatisfactory, the contactor worked and a red lamp lit up on the shore, which was visible from the tested ship.
Navy sailors in general, and ship crews in particular, knew that magnetic mines for non-demagnetized ships posed a terrible threat. Evidence of this was not only reports in the press or in relevant documents, but also the explosions of non-demagnetized ships in the Black and Baltic Seas. Therefore, sailors took the degaussing of ships very seriously. The situation was aggravated by the fact that the crews of the ships themselves did not outwardly feel how qualitatively their ship was demagnetized. Sometimes the sailors called the actions of the "demagnetists" black magic. For the crew, the quality of the ship's degaussing is not an abstract interest, but a matter of life. It is possible that the fact that the immediate supervisors and participants in the work were not the usual factory engineers and craftsmen, but "pure scientists", physicists, had a certain influence on the increase in interest in the demagnetization of ships. Now no one is surprised by the joint work of scientists and engineers, this is considered not only normal, but in some cases the most effective, and then it was still unusual.
Demagnetization is the process of reducing the magnetization of various metal objects.
Demagnetization is required in various fields of technology.
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In production, when working with tools, it is inconvenient to use a magnetized screwdriver or tweezers, small nuts and washers "stick" to the tool.
When processing products on machines, it is necessary that the metal part does not move after the moving devices of machines and units.
The main method of demagnetization is the impact on a magnetized object by an alternating magnetic field with a decreasing amplitude. Sometimes materials are demagnetized by heating to a certain high temperature.
Ship hulls, technical equipment, weapons, built of ferromagnetic materials, being in the Earth's magnetic field, are magnetized.
The magnetization of the ship consists of:
1) magnetization, which is acquired by the ship during its construction or long-term parking, the ship becomes a "permanent magnet";
2) magnetization, which is acquired by the ship at a given time, depending on the magnitude and direction of the Earth's magnetic field. It continuously changes with the change of the Earth's magnetic field and disappears if the Earth's magnetic field at the ship's location becomes equal to zero. This is how ships acquire their own magnetic fields.
Permanent magnetization is removed on special coastal or other mobile stands, and the magnetization obtained as a result of the action of the Earth's magnetic field is compensated using a demagnetizing device installed on the ship itself.
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Ships with a magnetized hull attract floating metal objects, and sea mines can become them. The ship's compass begins to give erroneous readings, mistaking the ship's magnetic field for the Earth's magnetic field. Therefore, in order to protect against sea mines and to increase the accuracy of the readings of the magnetic compass, both surface and underwater ships are subjected to demagnetization.
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The first non-contact magnetic mines appeared as early as 1919. In such mines, the iron arrow turned under the influence of the magnetic field of a ship sailing nearby and closed the fuse contacts. For such mines, it was not even necessary to touch the ship's hull!
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In the 30s of the 20th century, our scientists proposed to “demagnetize” the ships.
In 1937, the first successful experiments were carried out in Russia to demagnetize ships in Kronstadt.
In 1939, the demagnetized ship "Vyborny" successfully navigated over magnetic mines in Lake Onega.
In 1941, there was a transition to the stationary equipment of ships with demagnetizing installations (current-carrying windings that level the hull magnetization).
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During the Great Patriotic War, the demagnetization of submarines was of great importance, which was carried out without fail before they went to sea. Each boat had a special passport, which noted the state of its magnetic field. Degaussing saved more than one submarine from sinking
The principle of submarine demagnetization is as follows. The demagnetizing device consists of several (3 or 4) windings.
A direct current is passed through each winding in such a direction and such a magnitude that the magnetic field created by it is equal and opposite to one of the components of the magnetic field of the boat.
Did you know?
magnets and the brain
Physiologists have found that the use of a magnetic field contributes to the development of the brain in adults, the elderly and children.
Researcher Fortunato Battaglia from New York University, after conducting experiments, found that exposure to magnetic fields leads to the growth of new neurons in areas of the brain reserved for memory and learning. Magnetic brain stimulation has long been used to treat depression, schizophrenia, and the effects of strokes, in which magnetic fields restore speech to those affected. If new studies are confirmed, then doctors will have new prospects for treating various diseases (for example, Alzheimer's disease, which is accompanied by massive death of brain neurons) and correcting age-related changes in memory.
inquisitive
White clouds
Why are clouds mostly white and not blue like the sky? Why are thunderclouds black?
Turns out...
Scattering of light by objects much smaller than the wavelength of visible light is described by the Rayleigh scattering model. Water droplets in a cloud are usually larger and light is simply reflected from their outer surface. With this reflection, the light does not decompose into its component colors, but remains white. Very dense clouds appear black because they allow little sunlight to pass through - it is either absorbed by the water droplets in the cloud or reflected upward.
An electromagnet is usually used as a source of an alternating magnetic field. The decrease in the amplitude of the magnetic field acting on the object of demagnetization can be achieved by reducing the amplitude of the current in the electromagnet, or, in simpler cases, by increasing the distance between the electromagnet and the object being demagnetized. Since the magnetic properties of materials disappear when heated above a certain temperature, in production, in special cases, demagnetization is carried out using heat treatment (see Curie point).
Applications
Electron ray tube (CRT) devices
The term was first used during the 2nd World War by the commander of the Canadian Naval Reserve, Charles F. Goodive, who was trying to find protection against the German magnetic mines that caused serious damage to the British fleet.
Experiments to demagnetize ships during World War II may have given rise to the legend of the Philadelphia Experiment.
Elements of electromagnets
Electromagnets are used for electronic locks, relays, reed switches. In these devices, parts that were conceived by the developer as magnetically soft, that is, without their own magnetic induction in the absence of current in the coil, can become magnetized and render the device inoperative.
Tools and fixtures
When working with technological devices and tools, it is necessary that the material being processed, workpiece, part or product does not move after moving devices. This is especially true for handmade. For example, in many cases it is inconvenient to use a magnetized screwdriver, tweezers.
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Literature
- Tkachenko B. A. History of demagnetization of ships of the Soviet Navy / B. A. Tkachenko; USSR Academy of Sciences. . - L.: Science. Leningrad. department, 1981. - 224 p. - 10,000 copies.(in trans.)
Links
An excerpt characterizing Degaussing
- Give him some porridge; after all, it will not soon eat up from hunger.Again he was given porridge; and Morel, chuckling, set to work on the third bowler hat. Joyful smiles stood on all the faces of the young soldiers who looked at Morel. The old soldiers, who considered it indecent to engage in such trifles, lay on the other side of the fire, but occasionally, rising on their elbows, looked at Morel with a smile.
“People too,” said one of them, dodging in his overcoat. - And the wormwood grows on its root.
– Oo! Lord, Lord! How stellar, passion! To frost ... - And everything calmed down.
The stars, as if knowing that now no one would see them, played out in the black sky. Now flashing, now fading, now shuddering, they busily whispered among themselves about something joyful, but mysterious.
X
The French troops were gradually melting away in a mathematically correct progression. And that crossing over the Berezina, about which so much has been written, was only one of the intermediate steps in the destruction of the French army, and not at all the decisive episode of the campaign. If so much has been written and written about the Berezina, then on the part of the French this happened only because on the Berezinsky broken bridge, the disasters that the French army had previously suffered evenly, suddenly grouped here at one moment and into one tragic spectacle, which everyone remembered. On the part of the Russians, they talked and wrote so much about the Berezina only because far from the theater of war, in St. Petersburg, a plan was drawn up (by Pfuel) to capture Napoleon in a strategic trap on the Berezina River. Everyone was convinced that everything would actually be exactly as planned, and therefore they insisted that it was the Berezinsky crossing that killed the French. In essence, the results of the Berezinsky crossing were much less disastrous for the French in the loss of guns and prisoners than the Red, as the figures show.
The only significance of the Berezinsky crossing lies in the fact that this crossing obviously and undoubtedly proved the falsity of all plans for cutting off and the validity of the only possible course of action required by both Kutuzov and all the troops (mass) - only following the enemy. The crowd of Frenchmen ran with an ever-increasing force of speed, with all their energy directed towards the goal. She ran like a wounded animal, and it was impossible for her to stand on the road. This was proved not so much by the arrangement of the crossing as by the movement on the bridges. When the bridges were broken through, unarmed soldiers, Muscovites, women with children, who were in the French convoy - everything, under the influence of inertia, did not give up, but ran forward into the boats, into the frozen water.
This endeavor was reasonable. The position of both the fleeing and the pursuing was equally bad. Staying with his own, each in distress hoped for the help of a comrade, for a certain place he occupied among his own. Having given himself over to the Russians, he was in the same position of distress, but he was placed on a lower level in the section of satisfying the needs of life. The French did not need to have correct information that half of the prisoners, with whom they did not know what to do, despite all the desire of the Russians to save them, were dying of cold and hunger; they felt that it could not be otherwise. The most compassionate Russian commanders and hunters of the French, the French in the Russian service could not do anything for the prisoners. The French were ruined by the disaster in which the Russian army was. It was impossible to take away bread and clothes from hungry, necessary soldiers, in order to give them not to harmful, not hated, not guilty, but simply unnecessary Frenchmen. Some did; but that was the only exception.
Behind was certain death; there was hope ahead. The ships were burned; there was no other salvation but a collective flight, and all the forces of the French were directed to this collective flight.
The farther the French fled, the more miserable were their remnants, especially after the Berezina, on which, as a result of the St. Petersburg plan, special hopes were placed, the more the passions of the Russian commanders flared up, blaming each other and especially Kutuzov. Believing that the failure of the Berezinsky Petersburg plan would be attributed to him, dissatisfaction with him, contempt for him and teasing him were expressed more and more strongly. Joking and contempt, of course, was expressed in a respectful form, in a form in which Kutuzov could not even ask what and for what he was accused. He was not spoken seriously; reporting to him and asking his permission, they pretended to perform a sad ceremony, and behind his back they winked and tried to deceive him at every step.
All these people, precisely because they could not understand him, it was recognized that there was nothing to talk about with the old man; that he would never understand the full depth of their plans; that he would answer his phrases (it seemed to them that these were only phrases) about the golden bridge, that it was impossible to come abroad with a crowd of vagabonds, etc. They had already heard all this from him. And everything he said: for example, that you have to wait for provisions, that people are without boots, it was all so simple, and everything they offered was so complicated and clever that it was obvious to them that he was stupid and old, but they were not powerful, brilliant commanders.
Alexander Sergeevich Suvorov
About the service in the Navy. The legendary BOD "Fierce".
Weather report: Kaliningrad Wednesday 09 August 1972, daytime temperature: min: 14.8°C warm, average: 21.0°C warm, max: 28.7°C warm, no precipitation; Thursday 10 August 1972, daytime temperature: min: 13.8°C warm, average: 19.5°C warm, max: 25.2°C warm, no precipitation; Friday 11 August 1972, daytime temperature: min: 16.4°C warm, average: 20.7°C warm, max: 25.7°C warm, no precipitation.
The stage of mooring trials of the BOD "Svirepy" ended on August 09, 1972, when we were towed to the roadstead of the SBR (stand for windless demagnetization) of the Kaliningrad PSSZ "Yantar" (this is very close to the parking lot of the BOD "Svirepy", "to the right around the corner" of the factory outfitting wall, opposite the oil loading base on the other side of the sea channel - the author).
Degaussing a ship is the process of artificially reducing its magnetic field. The ship's magnetic field is a physical field, that is, a region of space adjacent to the ship's hull, in which the physical properties of the ship as a material object are manifested. The main types of physical fields of the ship: gravitational, acoustic, thermal (infrared), hydrodynamic, electromagnetic, magnetic and electric fields of the ship. The physical fields of the ship interact with the corresponding physical field of the World Ocean and the adjacent air space, therefore they leave a trace and can be detected at a distance by sensitive instruments.
Demagnetization is carried out using the windings of circuits powered by current, and is called electromagnetic processing (EMP) of the ship, while creating a magnetic field in a certain way, opposite in sign to the magnetic field of the ship. The dependence of the direction of the magnetic field, that is, the position of its poles, on the direction of the current is determined by the well-known "gimlet" rule. Demagnetization is carried out by two different methods - windingless and winding, but these names are conditional, since the demagnetization of ships by both one and the other method is performed using current-powered windings. True, in the first case, the windings are applied to the ship's hull temporarily, only for the period of demagnetization, or they are generally located outside the ship, and according to the second method of demagnetization, the windings are installed permanently in the ship's hull during its manufacture and turn them on while traveling through dangerous areas.
Windingless demagnetization (BR) is carried out by exposing the ship to temporarily created magnetic fields in two ways: with the help of electrical windings temporarily applied to the ship and with the help of circuits flowed around by current, laid on the ground, at the bottom of special water areas - BR polygons. With windingless demagnetization (BR), the ship's hull is exposed to damped alternating and constant magnetic fields, or to short-term exposure to only a constant magnetic field.
When the BOD "Svirepy" was made, its metal (steel) body inevitably became magnetized, acquired its own physical fields, moreover, in the vertical, longitudinal and transverse directions, and therefore it must be demagnetized in the same directions. With longitudinal demagnetization, the entire hull of the ship parallel to the waterline is surrounded by a cable through which a current of such magnitude is passed that the created electromagnetic field of the opposite sign exceeds the own magnetic field of the hull by 2-3 times. After a few seconds, the current in the winding is turned off and the ship's magnetic field is "rolled over". After that, a "compensation operation" is carried out, that is, a current is again turned on in the winding, the magnitude and direction of which are chosen so that after turning it off, the ship's magnetic field approaches zero as much as possible. Thus, the ship's magnetic field will not affect the detonators of enemy magnetic mines and magnetic torpedoes...
To create both permanent and alternating magnetic fields, one or more turns of cables are temporarily superimposed on the ship, connected to the power sources of special degaussing vessels. With longitudinal demagnetization, the ship is wrapped around its entire length with several turns of cables, like a coil, and the ship is enclosed inside a huge solenoid. When current is supplied to this selenoid winding, a volumetric magnetic field arises, acting along the axis of the solenoid, which demagnetizes the ship. With transverse demagnetization, two series-connected turns of cables along the sides are superimposed on the ship in a vertical plane. As a result, zero values of measurements of the ship's magnetic field are achieved in all directions.
Starting and winding the ship along and around the hull with heavy stranded copper cables in thick insulation is very hard work, which takes a lot of time and effort, but it is extremely necessary, as it ensures the safety of the ship and the accuracy of navigation - determining the location of the ship in the surrounding space of the Earth . Therefore, simultaneously with the winding of the ship with a cable, windingless demagnetization is carried out at a special station, where the windings (cable) are laid in a certain way on the ground of the water area of the ship's manufacturer.
The contours of the SBR cables (station without winding demagnetization), laid on the ground, have the shape of a loop. Therefore, such stations are also called "loop stations of non-winding demagnetization" (PSBR). The water area of the PSBR is fenced with buoys or milestones and there are barrels for mooring ships and vessels. A direct current is passed through the first circuit, and an alternating current with a frequency of 1 Hz is passed through the second circuit. An alternating magnetic field eliminates all irreversible phenomena that occur during magnetization in a constant magnetic field of a DC circuit. Degaussing on the FSBR is carried out by passing the appropriate currents through the circuits (bottom cables) at the moment when the ship is above them. The control of the current regime and the taking of readings of the magnetometric equipment is carried out remotely from the shore console.
This type of demagnetization of the BOD "Svirepy" will be received in December 1972 in a unique place - at the 1st training ground of the USSR Navy in the Khara-Lakht Bay (Suurpea village of the Estonian SSR) on unique stands:
- IK-2M for magnetic processing of ships;
- base "Oka" - lifting and lowering device for measuring the hydroacoustic field;
- stand "Pylon" - a 28-meter truss located under water, with hydrodynamic pressure sensors installed on it and sensors that determine the hydrology of the sea;
- deep-sea sonar stand, 80 km away from the main water area of the test site, etc.
On Thursday, August 10, 1972, the crew of the BOD "Svirepy" was offered to put all their wristwatches in boxes, we, navigators of the BS-1, removed all the ship's clocks from all bulkheads in all rooms and carried it all away under guard to the shore. Before that, on Wednesday, taking advantage of good clear weather, the ship was completely wrapped in cables for degaussing, and especially brave sailors remained on the ship to "sunbathe in a strong magnetic field" in order to receive either a "charge of sexual vigor" or "sexual solace". The process of demagnetization of the BOD "Svirepy" followed the principle of "hysteresis or semi-hysteresis magnetization reversal" and these words had a bewitching, magical, magnetic effect on the sailors. Some claimed that they felt a surge of strength and "male energy".
In fact, the electromagnetic field of windingless demagnetization acts only on the ship's hull, while the course and latitude changes in the ship's field are not compensated, therefore, it becomes necessary to periodically repeat the magnetic treatment due to the insufficient stability of the resulting field, and after each demagnetization, it is necessary to determine and eliminate the deviation (error) of the magnetic compasses. So we, the navigators, had enough worries and troubles on August 09-10, 1972 ...
In addition, I personally had to participate in the so-called "winding demagnetization", that is, in the production of compensation for the ship's magnetic fields by fields from stationary windings fed by current from special sources. The combination of the winding system, power sources, as well as control and monitoring equipment makes up the demagnetizing device (RU) of the ship. The RU creates a magnetic field at any moment of time as a "mirror image" of the ship's own magnetic field, while at each point under the ship the generated magnetic field is equal to the ship's field in magnitude, but opposite in sign. Thus, the resulting magnetic field has almost zero values (the ship becomes almost "invisible" to magnetic mines - the author). By the way, for the first time, RPs were developed during the Great Patriotic War of 1941-1945 by a group of employees of the Leningrad Institute of Physics and Technology of the USSR Academy of Sciences, headed by Academician A.P. Aleksandrov (I.V. Kurchatov, L.R. Stepanov K.K. Shcherbo, etc.). The degaussing device (RU) makes it possible to compensate for the ship's magnetic field, taking into account course and latitude changes.
The switchgear windings are installed inside the ship in the longitudinal, transverse and vertical directions, and the direction of the current in the windings is selected so that the magnetic field is opposite to the ship's own field to the field in these directions. These are the windings, hidden in special casings indoors in the bow and stern, according to the location of the frames and along the sides (buttock constant windings) I checked. To compensate for a multidirectional magnetic field, it is enough to set a certain and identical current mode in the windings, but it is more difficult to compensate for the inductive components of magnetization. To compensate for these components of the ship's magnetic field, the switchgear (demagnetizing device) includes adjustable windings: latitude, course frame windings and buttock course windings.
Winding demagnetization switchgear requires a lot of energy, costs a lot of money and effort to create scarce materials, but provides a greater degree of protection for ships from non-contact magnetic weapons and greater secrecy of the ship in the physical fields of the World Ocean.
Thus, - I told the guys while visiting combat posts and internal premises to revise the windings of the ship's switchgear (demagnetizing device), - behind these metal casings there are simple silent thick copper cables that protect us from magnetic mines and torpedoes, making us invisible in magnetic fields, which make it possible to accurately determine our location, the location (coordinates) of targets, and therefore shoot more accurately, hit the enemy and stay alive. Take care of these protective casings and take care of the RU equipment, because they are here for a reason, for beauty or interference, but for the self-defense of the ship, that is, all of us.
I honestly "did not poison the naval bike about the RU" (degaussing device), I spoke the truth. Practically all the sailors and foremen, old, old and young sailors looked with respect and attention at what I did and listened to what I said to them in my usual tired and businesslike tone. Everyone reacted to the demagnetization of our ship with understanding, which is why we all perceived the participation of our crew in laying and winding the ship's hull with heavy and easily soiled cables as a rush job, as a competition, as a kind of heroism. Literally everyone participated in this emergency work: officers, midshipmen, years old, juniors, young, seconded and newly arrived "newbies". This was our last "case" in the Mooring Test Program before receiving the first in the history of the BOD "Svirepy" Naval flag, which opens the way for us to the sea ...
Back in mid-July 1972, a special commission of representatives of all deliverers, military representatives and customers from the Navy decided on the date for entering the factory sea trials of the BOD "Svirepy" - August 12-13, 1972, for this period the date of hoisting on the ship of the Naval flag was set .
In the period from 09-11.08.1972, the BOD "Svirepy" underwent the first non-winding demagnetization at the factory roadstead of the SBR, which was provided by the degaussing vessel of the Baltic Fleet (possibly SR-570 - the author). Under the guidance of experienced workers and sailors of the special vessel SR-570, we unwound special heavy cable cables in black sticky and branded rubber insulation from huge coils, hooked them, increasing their length, and wound them under the hull of our ship, lifting these cable cables onto superstructures and even on our foremast and yardarms. As a result, the ship's hull was completely wrapped in cable-cables and turned into the core of an electromagnet - a selenoid.
On the Svirepom BOD, various work on fine-tuning machines and mechanisms, installation of new devices has not yet completely ended, so numerous specialists from different factories were present on the ship, ship designers and designers, service engineers and scientists from military institutes arrived from Leningrad. Everyone was in a good festive mood and perceived the time intended for degaussing the ship (for several days) as a kind of "vacation". The sailors of the crew of the BOD "Svirepy" also, despite the invisible magnetic fields, enjoyed sunbathing on the "roof" of the GKP and the wheelhouse during the work on degaussing, which is confirmed by a photo illustration from the DMB album of the radiotelegrapher Yury Vasilievich Kazennov, the period of his service 11/16/1970 - 11.1973. In the foreground of the picture Chervyakov Alexander Nikolayevich, service period 11/19/1970 - 11.1973, behind him with a Chapaev mustache, the commander of the mechanics department of the BP ZAS Morozov Nikolay Nikolayevich, service period 11/19/1970 - 11.1973, and behind him rises the radiotelegrapher Anosov Boris Alekseevich, service period 16.11 .1970-11.1973 (all from BCh-4). On the sides of the guys are visible double cable cables for degaussing.
The winding demagnetization of the BOD "Svirepy" at the SBR factory stand using a special vessel, possibly SR-570, was the last event before the first solemn hoisting of the Naval flag of the USSR Navy, because on August 10, 1972, the Commander of the Baltic Fleet, Admiral V.V. Mikhailin issued order No. 0432 on the enrollment of the newly built BOD "Svirepy" in the lists of combat surface ships of the Twice Red Banner Baltic Fleet.
What did it mean for us, the crew of the BOD "Svirepy", the issuance of such an order by the commander of the Baltic Fleet and the raising of the Naval flag? The first is, of course, pride in the fact that we completed the big tasks ahead of schedule, accepted and initially mastered the ship, and prepared for factory sea trials. The second is an increase in the monetary content and food standards from "land" (combined arms norms) to "marine" (navy). Thirdly, the beginning of real sea trials and adventures, because our ship had to start moving for the first time, pass narrowness along the Kaliningrad Sea Canal from the water area of \u200b\u200bthe native Kaliningrad Baltic shipbuilding plant Yantar to the Baltic naval base Baltiysk and stand there against the mooring wall - to its rightful place.
Photo illustration from Yuri Kazennov's DMB album: August 10, 1972. Kaliningrad. Kaliningrad Baltic shipyard "Yantar". Factory raid of the RRF, where in the period from 09 to 11 August 1972, the BOD "Svirepy" underwent non-winding demagnetization. In the foreground of the picture is the radiotelegraph operator Alexander Nikolayevich Chervyakov, service period 11/19/1970-11.1973, behind him with a Chapaev mustache, the commander of the mechanics department of the BP ZAS Morozov Nikolay Nikolayevich, service period 11/19/1970 - 11.1973, and behind him rises the radiotelegraph operator Anosov Boris Alekseevich, service period 11/16/1970 - 11/1973 (all from warhead-4). On the sides of the guys are visible double cable-cables of the demagnetization winding. From above, against the background of the coast, a ship's wind meter (KIV) is visible - my (author's) command as the helmsman of the warhead-1.
The short story uses data from the article by the authors Zinger M.A., Zakharov I.V. Application of innovative technologies in military shipbuilding // Topical issues of technical sciences: materials of the IV Intern. scientific conf. (Krasnodar, February 2017). - Krasnodar: Innovation, 2017. - S. 13-17.