Mine weapons in naval warfare

Captain 1st Rank Yu. Kravchenko

Sea mines are one of the most important weapons in naval warfare. They are designed to destroy warships and vessels, as well as to hinder their actions by creating a mine threat in certain areas (zones) of oceanic and maritime theaters of war and on inland waterways.

Mines were widely used by warring parties in naval combat in armed conflicts of various sizes. Their most widespread use took place during two world wars, which resulted in significant losses in warships and merchant ships.

During the First World War, approximately 309,000 mines were deployed in naval theaters. Allied and neutral losses from German mines (39,000) amounted to more than 50 warships, 225 naval auxiliary vessels and about 600 transports. The Entente countries were forced to invest huge amounts of money and make significant efforts to combat the mine threat. By the end of the war, the British Navy alone had over 700 minesweepers. The British fleet laid 128,000 mines, half of them in German-controlled waters.

During the war, large mine-laying operations were carried out, including joint efforts of coalition allies, with the aim of blocking the forces of the German fleet in the North Sea, primarily its submarines. Thus, the large northern barrier, created in 1918, had a length (from the Orkney Islands to the coast of Norway) of about 240 miles and a depth of 15 to 35 miles. More than 70,000 mines were deployed there by the United States and Great Britain. In total, about 150 enemy warships were lost to Allied mines (195,000), including 48 submarines.

The Second World War was distinguished by an even greater scale of the use of mine weapons, both in terms of expanding the area of ​​their use and in terms of an increase in the number of mines deployed (over 650,000). New mines based on the operating principle have appeared, their power has increased, the deployment depth has increased from 400 to 600 m, and the stability of mines against trawling has significantly increased. Only as a result of the laying of 263,000 mines by Great Britain in European waters (186 thousand in its coastal and 76 thousand in enemy waters), 1050 ships and vessels were killed and about 540 were damaged. Germany fielded 126,000 mines in this war, mostly in European waters. Allied losses amounted to about 300 warships up to and including the destroyer, as well as over 500 merchant ships.

Submarines and especially aviation were widely involved in laying minefields. The increased capabilities of aviation have significantly expanded the scope of the use of these weapons. An example of the massive use of mines is Operation Starvation, when US aircraft, from the end of March 1945, placed 12,000 mines on Japanese sea lanes in less than five months. On the night of March 27 alone, 99 B-29 aircraft from the 20th Bomber Command laid about 1,000 mines in the Shimonoseki Strait. This was the first time such a mass deployment by aviation had been carried out. As a result, up to 670 Japanese ships were sunk or damaged, that is, almost 75 percent. of all merchant tonnage available at the end of March 1945. During the operation, strategic bombers flew 1,529 sorties, losing 15 aircraft. Minefields practically paralyzed commercial shipping in the coastal waters of Japan, which significantly affected the state of the country's economy. In total, in World War II, on 25,000 mines laid by the United States, the Japanese lost 1,075 warships and vessels with a total tonnage of 2,289,146 tons sunk and damaged. This type of weapon was widely used in subsequent local wars and conflicts.

There are many types of mines, but their design is basically the same. A mine consists of a body, an explosive charge, a fuse, special devices (urgency, multiplicity, self-destruction and others), a power source, devices that ensure installation of the mine at a given depression from the surface of the water or on the ground, and also for some types - her movement. The carriers (layers) of mines are surface ships, submarines (Fig. 1), and aircraft. According to the principle of operation of the fuse, they are divided into contact and non-contact, according to the method of preserving the place of installation - into anchor (Fig. 2), bottom and floating, according to the degree of mobility - into self-propelled and stationary. Once laid, mines (minefields) can be unguided or controlled.

Most modern sea mines in the arsenal of the fleets of capitalist states have proximity fuses. They are triggered when a ship or vessel passes at a certain distance from a mine under the influence of one or more physical fields (acoustic, magnetic, hydrodynamic and others). According to this principle, proximity mines are divided into acoustic, magnetic, induction, and hydrodynamic.

Currently, sea mines of various designs and purposes are produced in the USA, Great Britain, Germany, France, Italy, Sweden, etc. niya and a number of other countries (Fig. 3). One of the most modern American mines is the Mk60 Captor. It is a combination of the Mk46 torpedo mod. 4 with a mine device and can be installed at depths of up to 800 m; the detection range of the detection system is 1000-1500 m. An example of a self-transporting mine is the Mk67 SLMM (Submarine - Launched Mobile Mine), developed in the USA on the basis of the Mk37 torpedo. After firing from the submarine’s torpedo tube, it independently reaches the intended deployment point, which can be located at a distance of up to 20 km from the carrier.

Rice. 1. Loading a mine onto a French Navy submarine

Fig. 2. Modern Swedish anchor mine K11 (explosive mass 80 kg, deployment depth from 20 to 200 m)

Rice. 3. Tests of the G-2 bottom mine jointly developed by Germany and Denmark

Rice. 4. Italian bottom mine MRP, created on the basis of the MR-80 mine (explosive mass 780 kg, length 2096 mm, diameter 533 mm)

Rice. 5. Laying mines from the S-130N military transport aircraft (can take on board up to 16 mines weighing about 1000 kg)

In the UK, seabed non-contact mines “Sea Uchin” and “Stone Fish” were created. The first is designed to destroy both underwater and surface targets. Its fuse can respond to changes in magnetic, acoustic and hydrodynamic (or combinations thereof) fields that arise in the area where the mine is installed as a result of a ship passing over it. Depending on the size and nature of the targets against which these mines are deployed, they can be equipped with explosive charges weighing 250, 500 and 750 kg. The depth of the mine is up to 90 m, its carriers are surface ships, submarines and aircraft. The weight of the Stonefish, depending on the amount of explosives, is 205-900 kg.

In Italy, the development and production of modern bottom mines is carried out by MISAR (MANTA, MR-80, Fig. 4), Voltek (VS SMG00) and Whitehead Motofaces (MP900/1, TAR6, TAR16). A typical example of an anchor mine developed and produced in Sweden by Bofors is the K11, also known as MM180. It is designed to combat surface ships and submarines of small and medium displacement. Explosive mass is 80 kg, deployment depth is from 20 to 200 m. The same company developed the original ROCAN bottom mine, which, due to its special hydrodynamic shapes, can, after being dropped from the carrier, move away from it in a horizontal plane to a distance equal to twice the depth of the sea at this point (hull mines are designed for a depth of up to 100 m, the minimum setting depth is 5 m).

Recently, a mine was created in Denmark, similar in principle to the American Mk60 Captor. Its main elements are: a container with a small-sized torpedo, an anchor device and equipment for a target detection and classification system that responds to changes in acoustic and magnetic fields. After detecting and classifying the target (the main purpose of the mine is to fight against mine-resistant ships), a torpedo is launched, which is aimed at the target using the radiation of a working mine detection sonar. The adoption of such a mine into service by the fleets of capitalist states can significantly increase the anti-mine resistance of the minefields they deploy.
Along with the creation of new types of mines, significant attention is paid to improving naval mines of outdated types (installation of new fuses, use of more powerful explosives). Thus, in Great Britain, old Mk12 mines were equipped with fuses similar to those found on modern seabed "Sea Uchin" mines. All this allows previously accumulated mine reserves to be maintained at the current level* .

Mine weapons have an important combat property - they have a long-lasting effect on the enemy, creating a constant threat to the navigation of his ships and vessels in mined areas of the sea. It allows you to free up forces to solve other problems, it can reduce the size of an area blocked by other forces, or temporarily close it completely. Mines dramatically change the operational situation in a theater of war and give an advantage to the side that used them in gaining and maintaining supremacy at sea.

Mines are a universal weapon and are capable of hitting not only military targets, but also effectively affecting the country's economy and military production. The massive use of mine weapons can significantly disrupt or completely interrupt sea and ocean transportation. Mine weapons can be an instrument of precisely calculated military pressure (in a certain situation, it is possible to block a naval base or port for a certain period of time in order to demonstrate to the enemy the effect of a possible blockade).

Mines are a fairly “flexible” type of weapon in terms of their use. The side laying mines can either openly announce it to exert a psychological influence on the enemy, or organize the laying of a minefield covertly to achieve surprise and inflict maximum damage on enemy forces.

Foreign military experts believe that any issues related to mine laying should be considered in the context of the general views of the NATO command on the conduct of war, and in particular on the conduct of naval operations. In relation to the Atlantic theater of war, the main task that will be solved with the start of hostilities of the bloc's Allied Forces in the theater will be to gain supremacy at sea in the interests of ensuring the protection of transatlantic communications connecting the United States of America with Europe. Violation of them will have the most serious impact on the possibilities of waging war in Europe. As emphasized in the foreign press, without the timely transfer of reinforcement forces, weapons, military equipment and logistics equipment to the continent, the NATO Allied Forces group will be able to conduct combat operations for no more than 30 days. It is also noted that during the first six months of the conflict in Western Europe, ocean transportation should ensure the delivery from the United States of over 1.5 million personnel, about 8.5 million tons of weapons, military equipment and supplies, as well as 15 million. tons of fuels and lubricants. According to NATO experts, to achieve this goal, it is necessary that from 800 to 1000 ships with military cargo and 1500 with economic cargo (minerals, food, etc.) arrive at European ports monthly.

This extremely important task for the Alliance must be achieved through a strategic operation in the ocean theater of war. It will include a series of interconnected NATO operations in terms of objectives, location and time to gain dominance in the Norwegian and Barents Seas (destroying enemy fleet forces and preventing them from entering the Atlantic to disrupt communications), in coastal European waters (ensuring the arrival of ships with forces on the continent reinforcements), in the central part of the ocean (destruction of enemy force groups that have broken through) and in waters adjacent to the Atlantic coast of the United States (covering coastal communications, protecting ports, loading areas and convoy formation). In all these operations, mine weapons must play an important role. In addition, it will be widely used in solving other tasks - blockade of the enemy’s ports and naval bases, strait zones and bottlenecks in order to disrupt the operational deployment of his forces, and primarily strategic ones; blocking enemy fleets in the closed seas (Black and Baltic); disruption of its sea and river communications; the creation of a regime unfavorable for the enemy in the theater, making it difficult for him to conduct not only operations, but also daily combat activities and causing a significant strain of forces and resources, additional consumption of material and human resources due to the need for constant implementation of mine defense measures; preventing the enemy from entering certain areas of the naval theater, covering one’s ports and naval bases, landing areas of the coast from attacks from the sea, and a number of others.

Minefields can be deployed during daily combat activities and during various naval operations. If it is necessary to lay large minefields in a relatively short period of time, special minelaying operations are organized and carried out.

According to the NATO classification, minefields, depending on the areas of deployment, can be active (placed in waters controlled by the enemy), barrier (in neutral waters) and defensive (in their own waters), according to the tasks being solved - operational and tactical scale, according to the number of mines in fence - minefields and mine banks. Depending on the depths of the sea available for mine laying, shallow-water areas (20-20.0 m), medium-depth (200-400 m) and deep-water (over 400 m) are distinguished.

The role of mine weapons in gaining dominance of the combined NATO naval forces in the Barents and Norwegian Seas is highly appreciated. The laying of active minefields is supposed to be carried out 1-3 days before the start of hostilities in order to destroy the forces of the enemy fleet, primarily submarines, prevent the deployment of its naval groups into the Atlantic, disrupt coastal communications, create an unfavorable regime in the theater, and support landing operations. Anti-submarine minefields (active and barrier) will be placed at naval bases and bases, at anti-submarine lines (North Cape - Bear Island, Greenland Island - Iceland - Faroe Islands - Shetland Islands - coast of Norway), as well as in SSBN combat patrol areas. Defensive minefields are intended to be used to protect coastal sea communications, cover amphibious accessible sections of the coast in Northern Norway, and unloading areas for convoys arriving at the North European theater of operations with reinforcement troops, weapons, military equipment and logistics equipment.

Foreign military experts believe that the enemy will widely use mine weapons in coastal European waters: in the North Sea, the Baltic Strait zone, the English Channel, primarily with the aim of disrupting ocean shipping to Europe. Combating the mine threat in these areas will be one of the main tasks for the joint NATO naval forces. At the same time, NATO headquarters are developing plans for the active use of mine weapons in operations and combat operations to disrupt enemy sea communications in the Baltic Sea, destroy fleet groups of Warsaw Pact countries, blockade the strait zone, and protect their communications. For mine laying, it is planned to widely involve submarines capable of secretly placing mines in close proximity to the enemy’s coast, as well as aviation. Light surface forces (minesweepers, missile and torpedo boats), minelayers will be used to lay defensive minefields in order to block the strait zone to prevent the breakthrough of ship groupings of the Warsaw Pact fleets from the Baltic Sea to the Atlantic, to protect ports and coastal communications and cover landing forces. accessible areas of the coast. As emphasized in the Western press, when conducting combat operations in the Baltic and North Seas, “mine laying plays an important role as an effective element of naval warfare against the threat from a potential enemy.”

The use of mine weapons in the Mediterranean Sea will be determined by the tasks solved by the strike and combined NATO naval forces in the theater of operations, the main of which will be the following: gaining and maintaining dominance in certain areas of the sea, establishing a blockade of the Black Sea and Gibraltar Straits, ensuring convoys with reinforcement troops and various items Logistics, conducting amphibious operations, protecting your communications. Taking into account the tasks to be solved, as well as the physical and geographical conditions of the Mediterranean Sea, the most likely areas for laying minefields are the Gibraltar, Tunisian, Maltese, Messina and Black Sea Straits, the Aegean Sea, coastal zones on the approaches to naval bases, ports and landing areas of the coast.

Laying minefields can be carried out by aircraft, submarines and surface ships. Each type of force involved for these purposes has both positive and negative properties. That is why the laying of minefields should be carried out, depending on the goals, objectives, place and time, either by one type of force or by several.

Rice. b. Loading mines onto a Project 206 submarine and container device MWA-09

Rice. 7. Swedish clay minelayer “Elvsborg”

Rice. 8. Japanese minelayer “Soya” (full displacement 3050 tons. Takes on board up to 460 mines)

Rice. 9. Laying mines from a US Navy Knox-class frigate

Rice. 10. Laying mines from a boat

Aviation is capable of laying mines in enemy waters and areas of oceans (sea) remote from bases in short periods of time with fairly high accuracy and regardless of meteorological conditions. It will be used, as a rule, for massive mining of large areas of water.

The United States has the greatest ability among NATO countries to lay mines from the air. For this purpose, it is possible to use aircraft of various types: strategic bombers B-52 and B-1B, carrier-based attack aircraft A-6E "Intruder" and A-7E "Corsair", anti-submarine aircraft S-3A and B "Viking", basic patrol aircraft R- ZS "Orion", as well as attract military transport aircraft C-130 "Hercules" (Fig. 5), C-141 "Starlifter" and C-5 "Galaxy", modernized under the CAML (Cargo Aircraft Minelaying) program.

The largest number of mines can be carried on board by the B-52 strategic bombers (from 30 to 51 Mk52 and MkZ6 bottom mines, respectively, or 18 Mk60 Captor deep-sea anti-submarine mines, or 18 Mk64 and 65 of the Quickstrike family) and B-1B (84,250 -kg bottom mines MkZ6). The combat radius of such aircraft, taking into account one refueling in the air, makes it possible to lay mines in almost any area of ​​the World Ocean.

The mine load of the basic patrol aircraft R-ZS "Orion" is 18 mines MkZ6, 40 and 62 (weighing 230-260 kg each), or 11 Mk52 (about 500 kg), or seven Mk55, 56, 57, 60, 41, 64 and 65 (up to 1000 kg). The deck-based attack aircraft A-6E "Intruder" and A-7E "Corsair" on underwing hardpoints deliver five and six mines weighing 900-1000 kg, respectively, to the deployment area, and the anti-submarine aircraft S-3A "Viking" in the minelayer version takes on board two 1000 kg mines and four weighing up to 250 kg. When assessing the capabilities of US Navy carrier aviation to lay minefields, foreign military experts proceed from the following factors: the air wing based on a multi-purpose aircraft carrier (86 aircraft and helicopters) has about 40 percent. carriers of mine weapons, including 20 A-6E Intruder medium attack aircraft and 10 S-3A and B Viking anti-submarine aircraft, and the basic patrol aircraft of the US Navy (regular forces) includes 24 squadrons (216 aircraft).

Taking into account the long range and speed of aircraft, their efficiency in laying minefields, the ability to lay mines in areas that are inaccessible for a number of reasons to surface ships and submarines, as well as the ability to reinforce previously laid minefields in a fairly short time, aviation when conducting combat operations in in modern conditions it will be one of the main carriers of mine weapons. Among the disadvantages of aviation as a carrier of mines, foreign experts include the relatively low secrecy of its mine laying. To disguise the fact that approaches to ports, naval bases, narrow passages, fairways, and communications nodes are being mined, it is possible to launch simultaneous missile and bomb attacks on enemy targets located in the same area.

Submarines, due to their inherent qualities, have the ability to secretly lay mines in the most important places, and also, while remaining in the area of ​​the minefield, monitor it in order to determine its effectiveness and develop the success achieved through the use of torpedo weapons. Operating alone, they can be effectively used to deploy small active minefields (cans) on the approaches to naval bases, ports, in enemy communications nodes, in narrow areas, and on anti-submarine lines.

For these purposes, it is planned to attract both nuclear-powered multi-purpose and diesel submarines. They lay mines mainly using torpedo tubes; it is also possible to use mounted external devices for this. American nuclear attack submarines (with the exception of Los Angeles-class submarines) can be used as minelayers, taking on board instead of part of the torpedoes, PLUR SABROC or Harpoon anti-ship missiles the Mk60 Captor, Mk67 SLMM, Mk52, 55 and 56.

The main disadvantages of submarines as carriers of mine weapons is that they are capable of carrying only a limited number of mines. To eliminate this drawback to some extent, special attachments have been created for certain types of submarines. Thus, the German Navy has a similar device for Project 206 submarines, designated MWA-09 (Fig. 6). It consists of two containers with a capacity of 12 mines, which, if necessary, are attached by the crew in the base on the side to the hull of the boat in its bow. Mine placement can be carried out underwater at speeds up to 12 knots. With the use of the MWA-09 device, the ammunition load of mines for submarines of this project should increase from 16 to 40 units, that is, 2.5 times (provided that mines are loaded into torpedo tubes instead of torpedoes).

Historically, the main carriers of mine weapons are surface ships. Based on the experience of armed conflicts, they placed primarily defensive minefields. This was due to the fact that the involvement of surface ships to lay mines in waters controlled by the enemy required the allocation of special forces to provide cover, as well as the organization of navigation support.

In future conflicts at sea, the navies of NATO countries are expected to use both specially built minelayers (Germany, Norway, see color insert, Denmark, Turkey, Greece) and warships of various classes, including auxiliary vessels, sometimes transports and ferries . Minelayers are also part of the Swedish (Fig. 7) and Japanese (Fig. 8) navies. They are capable of taking on board a large number of mines, for example, the West German mine transport of the Sachsenwald type, having a total displacement of 3380 tons, can deploy from 400 to 800 mines at sea, depending on their type.

However, there are relatively few special minelayers, and therefore high-speed warships (destroyers, frigates), missile and torpedo boats will be involved in large-scale mine laying. Much attention is paid to the preparation of surface ships for use as minelayers in the navies of European NATO countries. Thus, almost all warships and boats of the West German fleet are adapted for mine laying. New ships are also built with this in mind. For example, high-speed minesweepers of the Hameln type entering the fleet can take on board up to 60 mines. On surface ships of the US Navy there are no stationary rail tracks designed for receiving and laying mines, but devices have been developed that make it possible to quickly deploy places on the ship for storing and discharging them (Fig. 9).

The naval commands of NATO countries plan to engage ships and boats (Fig. 10) of civilian departments and private owners to lay defensive minefields during a period of threat and with the outbreak of hostilities. So, in the USA, for example, activities for the selection of suitable vessels (boats) and training of crews for them are carried out within the framework of the COOP (Craft of Opportunity Program) program. These are vessels of small displacement, have a wooden hull and enough free space on the deck to accept mines on board or installation of mine-sweeping equipment specially created for them (in the version of a minesweeper - mine finder). COOP ships are assigned to a specific port, and their crews are trained from reservists. Similar programs exist in a number of European NATO countries.

According to foreign military experts, the importance of mine weapons in combat operations at sea will increase and they will be widely used for both offensive and defensive purposes. At the same time, it is emphasized that the greatest effect can be achieved with the massive use of mines in combination with the use of other combat weapons that are available to the fleets.

* Basic tactical and technical characteristics of samples min. in service with the fleets of capitalist states, see: Foreign Military Review. - 1989. - No. 8. - P. 48. - Ed.

Foreign Military Review No. 9 1990 P. 47-55

A sea mine is a self-sufficient mine placed in water for the purpose of damaging or destroying the hulls of ships, submarines, ferries, boats and other watercraft. Unlike mines, they are in a “sleeping” position until they contact the side of the ship. Naval mines can be used both to cause direct damage to the enemy and to impede his movements in strategic directions. In international law, the rules for conducting mine warfare were established by the 8th Hague Convention of 1907.

Classification

Sea mines are classified according to the following criteria:

• Type of charge - conventional, special (nuclear).
• Degrees of selectivity - normal (for any purpose), selective (recognize the characteristics of the vessel).
• Controllability - controllable (by wire, acoustically, by radio), uncontrollable.
• Multiplicities - multiples (a given number of targets), non-multiple.
• Type of fuse - non-contact (induction, hydrodynamic, acoustic, magnetic), contact (antenna, galvanic impact), combined.
• Type of installation - homing (torpedo), pop-up, floating, bottom, anchor.

Mines usually have a round or oval shape (with the exception of torpedo mines), ranging in size from half a meter to 6 m (or more) in diameter. Anchor ones are characterized by a charge of up to 350 kg, bottom ones - up to a ton.

Historical reference

Sea mines were first used by the Chinese in the 14th century. Their design was quite simple: under the water there was a tarred barrel of gunpowder, to which a wick led, supported on the surface by a float. To use it, it was necessary to light the wick at the right moment. The use of similar designs is already found in treatises of the 16th century in China, but a more technologically advanced flint mechanism was used as a fuse. Improved mines were used against Japanese pirates.

In Europe, the first sea mine was developed in 1574 by the Englishman Ralph Rabbards. A century later, the Dutchman Cornelius Drebbel, who served in the artillery department of England, proposed his design of ineffective “floating firecrackers”.

American developments

A truly formidable design was developed in the United States during the Revolutionary War by David Bushnell (1777). It was the same powder keg, but equipped with a mechanism that detonated upon collision with the hull of the ship.

At the height of the Civil War (1861) in the United States, Alfred Waud invented a double-hulled floating sea mine. They chose a suitable name for it - “hell machine”. The explosive was located in a metal cylinder located under water, which was held by a wooden barrel floating on the surface, which simultaneously served as a float and a detonator.

Domestic developments

The first electric fuse for “infernal machines” was invented by Russian engineer Pavel Schilling in 1812. During the unsuccessful siege of Kronstadt by the Anglo-French fleet (1854) in the Crimean War, the naval mine designed by Jacobi and Nobel proved to be excellent. The fifteen hundred "infernal machines" on display not only hampered the movement of the enemy fleet, but they also damaged three large British steamships.

The Jacobi-Nobel mine had its own buoyancy (thanks to air chambers) and did not need floats. This made it possible to install it secretly, in the water column, hanging it on chains, or to let it go with the flow.

Later, a spheroconic floating mine was actively used, held at the required depth by a small and inconspicuous buoy or anchor. It was first used in the Russian-Turkish War (1877-1878) and was in service with the navy with subsequent improvements until the 1960s.

Anchor mine

It was held at the required depth by the anchor end - a cable. The sinking of the first samples was ensured by manually adjusting the length of the cable, which required a lot of time. Lieutenant Azarov proposed a design that made it possible to automatically install sea mines.

The device was equipped with a system consisting of a lead weight and an anchor suspended above the weight. The anchor end was wound onto a drum. Under the action of the load and anchor, the drum was released from the brake, and the end was reeled out of the drum. When the load reached the bottom, the pulling force of the end decreased and the drum locked, due to which the “infernal machine” sank to a depth corresponding to the distance from the load to the anchor.

Early 20th century

Sea mines began to be used en masse in the twentieth century. During the Boxer Rebellion in China (1899-1901), the imperial army mined the Haife River, covering the route to Beijing. In the Russian-Japanese confrontation of 1905, the first mine war unfolded, when both sides actively used massive barrages and breakthroughs with the help of minesweepers.

This experience was adopted into the First World War. German sea mines prevented British landings and hampered the operations of the submarines, which mined trade routes, bays and straits. The Allies did not remain in debt, practically blocking the exits from the North Sea for Germany (this required 70,000 mines). Experts estimate the total number of “infernal machines” in use at 235,000.

World War II naval mines

During the war, about a million mines were placed in naval theaters of combat, including more than 160,000 in the waters of the USSR. Germany installed weapons of death in the seas, lakes, rivers, in the ice and in the lower reaches of the Ob River. Retreating, the enemy mined port berths, roadsteads, and harbors. The mine war in the Baltic was especially brutal, where the Germans delivered more than 70,000 units in the Gulf of Finland alone.

As a result of mine explosions, approximately 8,000 ships and vessels sank. In addition, thousands of ships were heavily damaged. In European waters already in the post-war period, 558 ships were blown up by sea mines, 290 of which sank. On the very first day of the start of the war, the destroyer Gnevny and the cruiser Maxim Gorky were blown up in the Baltic.

German mines

At the beginning of the war, German engineers surprised the Allies with new highly effective types of mines with a magnetic fuse. The sea mine did not explode due to contact. The ship only had to sail close enough to the deadly charge. Its shock wave was enough to turn the side. Damaged ships had to abort the mission and return for repairs.

The English fleet suffered more than others. Churchill personally made it his highest priority to develop a similar design and find an effective means of clearing mines, but British experts could not reveal the secret of the technology. Chance helped. One of the mines dropped by a German plane got stuck in the coastal mud. It turned out that the explosive mechanism was quite complex and was based on the Earth. Research has helped create effective

Soviet naval mines were not as technologically advanced, but no less effective. The main models used were the KB "Crab" and AG. The "Crab" was an anchor mine. The KB-1 was put into service in 1931, and the modernized KB-3 in 1940. Designed for mass mine laying; in total, the fleet had about 8,000 units at its disposal at the beginning of the war. With a length of 2 meters and a mass of over a ton, the device contained 230 kg of explosives.

The deep-sea antenna mine (AG) was used to sink submarines and ships, as well as to impede the navigation of the enemy fleet. In essence, it was a modification of the design bureau with antenna devices. During combat deployment in sea water, the electrical potential was equalized between the two copper antennas. When the antenna touched the hull of a submarine or ship, the potential balance was disturbed, which caused the ignition circuit to close. One mine “controlled” 60 m of space. General characteristics correspond to the KB model. Later, copper antennas (requiring 30 kg of valuable metal) were replaced with steel ones, and the product received the designation AGSB. Few people know the name of the AGSB model sea mine: a deep-sea antenna mine with steel antennas and equipment assembled into a single unit.

Mine clearance

70 years later, sea mines from World War II still pose a danger to peaceful shipping. A large number of them still remain somewhere in the depths of the Baltic. Before 1945, only 7% of the mines were cleared; the rest required decades of dangerous clearance work.

The main burden of the fight against mine danger fell on the personnel of minesweeper ships in the post-war years. In the USSR alone, about 2,000 minesweepers and up to 100,000 personnel were involved. The degree of risk was exceptionally high due to constantly opposing factors:

• the unknown boundaries of minefields;
• different mine installation depths;
• various types of mines (anchor, antenna, with traps, bottom non-contact mines with urgency and frequency devices);
• the possibility of being hit by fragments of exploding mines.

Trawling technology

The trawling method was far from perfect and dangerous. At the risk of being blown up by mines, the ships walked through the minefield and pulled the trawl behind them. Hence the constant stress of people from anticipation of a deadly explosion.

A mine cut by a trawl and a surfaced mine (if it did not explode under the ship or in the trawl) must be destroyed. When the sea is rough, attach a blasting cartridge to it. Detonating a mine is safer than shooting it out, since the shell often pierced the shell of the mine without touching the fuse. An unexploded military mine lay on the ground, presenting a new danger that could no longer be eliminated.

Conclusion

The sea mine, the photo of which inspires fear by its mere appearance, is still a formidable, deadly, and at the same time cheap weapon. Devices have become even more “smart” and more powerful. There are developments with an installed nuclear charge. In addition to the listed types, there are towed, pole, throwing, self-propelled and other “infernal machines”.

Naval ammunition included the following weapons: torpedoes, sea mines and depth charges. A distinctive feature of these ammunition is the environment in which they are used, i.e. hitting targets on or under water. Like most other ammunition, naval ammunition is divided into main (for hitting targets), special (for illumination, smoke, etc.) and auxiliary (training, blank, for special tests).

Torpedo- a self-propelled underwater weapon consisting of a cylindrical streamlined body with tails and propellers. The warhead of a torpedo contains an explosive charge, a detonator, fuel, an engine and control devices. The most common caliber of torpedoes (hull diameter at its widest part) is 533 mm; samples from 254 to 660 mm are known. The average length is about 7 m, weight is about 2 tons, explosive charge is 200-400 kg. They are in service with surface (torpedo boats, patrol boats, destroyers, etc.) and submarines and torpedo bomber aircraft.

Torpedoes were classified as follows:

- by type of engine: combined-cycle (liquid fuel burns in compressed air (oxygen) with the addition of water, and the resulting mixture rotates a turbine or drives a piston engine); powder (gases from slowly burning gunpowder rotate the engine shaft or turbine); electric.

— by guidance method: unguided; erect (with a magnetic compass or gyroscopic semi-compass); maneuvering according to a given program (circulating); homing passive (based on noise or changes in the properties of water in the wake).

— by purpose: anti-ship; universal; anti-submarine.

The first samples of torpedoes (Whitehead torpedoes) were used by the British in 1877. And already during the First World War, steam-gas torpedoes were used by the warring parties not only in the sea, but also on rivers. The caliber and dimensions of torpedoes tended to steadily increase as they developed. During the First World War, torpedoes of 450 mm and 533 mm caliber were standard. Already in 1924, the 550-mm steam-gas torpedo “1924V” was created in France, which became the first-born of a new generation of this type of weapon. The British and Japanese went even further, designing 609-mm oxygen torpedoes for large ships. Of these, the most famous is the Japanese type “93”. Several models of this torpedo were developed, and on the “93” modification, model 2, the charge mass was increased to 780 kg to the detriment of range and speed.

The main “combat” characteristic of a torpedo—the explosive charge—usually not only increased quantitatively, but also improved qualitatively. Already in 1908, instead of pyroxylin, the more powerful TNT (trinitrotoluene, TNT) began to spread. In 1943, in the United States, a new explosive, “torpex,” was created specifically for torpedoes, twice as strong as TNT. Similar work was carried out in the USSR. In general, during the Second World War alone, the power of torpedo weapons in terms of the TNT coefficient doubled.

One of the disadvantages of steam-gas torpedoes was the presence of a trace (exhaust gas bubbles) on the surface of the water, unmasking the torpedo and creating the opportunity for the attacked ship to evade it and determine the location of the attackers. To eliminate this, it was planned to equip the torpedo with an electric motor. However, before the outbreak of World War II, only Germany succeeded. In 1939, the Kriegsmarine adopted the G7e electric torpedo. In 1942, it was copied by Great Britain, but was able to establish production only after the end of the war. In 1943, the ET-80 electric torpedo was adopted for service in the USSR. However, only 16 torpedoes were used until the end of the war.

To ensure a torpedo explosion under the bottom of the ship, which caused 2-3 times more damage than an explosion at its side, Germany, the USSR and the USA developed magnetic fuses instead of contact fuses. The German TZ-2 fuses, which were put into service in the second half of the war, achieved the greatest efficiency.

During the war, Germany developed maneuvering and torpedo guidance devices. Thus, torpedoes equipped with the “FaT” system during the search for a target could move “snake” across the ship’s course, which significantly increased the chances of hitting the target. They were most often used towards a pursuing escort ship. Torpedoes with the LuT device, produced since the spring of 1944, made it possible to attack an enemy ship from any position. Such torpedoes could not only move like a snake, but also turn around to continue searching for a target. During the war, German submariners fired about 70 torpedoes equipped with LuT.

In 1943, the T-IV torpedo with acoustic homing (ASH) was created in Germany. The torpedo's homing head, consisting of two spaced hydrophones, captured the target in the 30° sector. The capture range depended on the noise level of the target ship; usually it was 300-450 m. The torpedo was created mainly for submarines, but during the war it also entered service with torpedo boats. In 1944, the modification “T-V” was released, and then “T-Va” for “schnellboats” with a range of 8000 m at a speed of 23 knots. However, the effectiveness of acoustic torpedoes turned out to be low. The overly complex guidance system (it included 11 lamps, 26 relays, 1760 contacts) was extremely unreliable - out of 640 torpedoes fired during the war, only 58 hit the target. The percentage of hits with conventional torpedoes in the German fleet was three times higher.

However, the Japanese oxygen torpedoes had the most powerful, fastest and longest range. Neither allies nor opponents were able to achieve even close results.

Since there were no torpedoes equipped with the maneuvering and guidance devices described above in other countries, and Germany had only 50 submarines capable of launching them, a combination of special ship or aircraft maneuvers was used to launch torpedoes to hit the target. Their totality was defined by the concept of torpedo attack.

A torpedo attack can be carried out: from a submarine against enemy submarines, surface ships and ships; surface ships against surface and underwater targets, as well as coastal torpedo launchers. The elements of a torpedo attack are: assessing the position relative to the detected enemy, identifying the main target and its protection, determining the possibility and method of a torpedo attack, approaching the target and determining the elements of its movement, choosing and occupying a firing position, firing torpedoes. The end of a torpedo attack is torpedo firing. It consists of the following: the firing data is calculated, then they are entered into the torpedo; The ship performing torpedo firing takes a calculated position and fires a salvo.

Torpedo firing can be combat or practical (training). According to the method of execution, they are divided into salvo, aimed, single torpedo, area, successive shots.

Salvo firing consists of the simultaneous release of two or more torpedoes from torpedo tubes to ensure an increased probability of hitting the target.

Targeted shooting is carried out in the presence of accurate knowledge of the elements of the target’s movement and the distance to it. It can be carried out with single torpedo shots or salvo fire.

When firing torpedoes over an area, torpedoes cover the probable area of ​​the target. This type of shooting is used to cover errors in determining the elements of target movement and distance. A distinction is made between sector firing and parallel torpedo firing. Torpedo firing over an area is carried out in one salvo or at time intervals.

Torpedo firing by sequential shots means firing in which torpedoes are fired sequentially one after another at specified time intervals to cover errors in determining the elements of the target’s movement and the distance to it.

When firing at a stationary target, the torpedo is fired in the direction of the target; when firing at a moving target, it is fired at an angle to the direction of the target in the direction of its movement (with anticipation). The lead angle is determined taking into account the target's heading angle, the speed of movement and the path of the ship and torpedo before they meet at the lead point. The firing distance is limited by the maximum range of the torpedo.

In World War II, about 40 thousand torpedoes were used by submarines, aircraft and surface ships. In the USSR, out of 17.9 thousand torpedoes, 4.9 thousand were used, which sank or damaged 1004 ships. Of the 70 thousand torpedoes fired in Germany, submarines expended about 10 thousand torpedoes. US submarines used 14.7 thousand torpedoes, and torpedo-carrying aircraft 4.9 thousand. About 33% of the fired torpedoes hit the target. Of all ships and vessels sunk during the Second World War, 67% were torpedoes.

Sea mines- ammunition secretly installed in the water and designed to destroy enemy submarines, ships and vessels, as well as to impede their navigation. The main properties of a sea mine: constant and long-term combat readiness, surprise of combat impact, difficulty in clearing mines. Mines could be installed in enemy waters and off their own coast. A sea mine is an explosive charge enclosed in a waterproof casing, which also contains instruments and devices that cause the mine to explode and ensure safe handling.

The first successful use of a sea mine took place in 1855 in the Baltic during the Crimean War. The ships of the Anglo-French squadron were blown up by galvanic shock mines laid by Russian miners in the Gulf of Finland. These mines were installed under the surface of the water on a cable with an anchor. Later, shock mines with mechanical fuses began to be used. Sea mines were widely used during the Russo-Japanese War. During the First World War, 310 thousand sea mines were installed, from which about 400 ships sank, including 9 battleships. In World War II, proximity mines (mainly magnetic, acoustic and magnetic-acoustic) appeared. Urgency and multiplicity devices and new anti-mine devices were introduced into the design of non-contact mines.

Sea mines were installed both by surface ships (minelayers) and from submarines (through torpedo tubes, from special internal compartments/containers, from external trailer containers), or dropped by aircraft (usually into enemy waters). Anti-landing mines could be installed from the shore at shallow depths.

Sea mines were divided according to the type of installation, according to the principle of operation of the fuse, according to the frequency of operation, according to controllability, and according to selectivity; by media type,

By type of installation there are:

- anchored - a hull with positive buoyancy is held at a given depth under water at an anchor using a minerep;

- bottom - installed on the bottom of the sea;

- floating - drifting with the flow, staying under water at a given depth;

- pop-up - installed on an anchor, and when triggered, it releases it and floats up vertically: freely or with the help of a motor;

- homing - electric torpedoes held underwater by an anchor or lying on the bottom.

According to the principle of operation of the fuse, they are distinguished:

— contact — exploding upon direct contact with the ship’s hull;

- galvanic impact - triggered when a ship hits a cap protruding from the mine body, which contains a glass ampoule with the electrolyte of a galvanic cell;

- antenna - triggered when the ship's hull comes into contact with a metal cable antenna (used, as a rule, to destroy submarines);

- non-contact - triggered when a ship passes at a certain distance from the influence of its magnetic field, or acoustic influence, etc. Non-contact ones are divided into: magnetic (react to the target’s magnetic fields), acoustic (react to acoustic fields), hydrodynamic (react to dynamic change in hydraulic pressure from the movement of the target), induction (react to changes in the strength of the ship’s magnetic field (the fuse is triggered only under a ship that is moving), combined (combining fuses of different types). To make it difficult to combat proximity mines, emergency devices were included in the fuze circuit, delaying the bringing of a mine into a firing position for any required period, multiplicity devices that ensure the explosion of a mine only after a specified number of impacts on the fuse, and decoy devices that cause a mine to explode when an attempt is made to disarm it.

According to the multiplicity of mines, there are: non-multiple (triggered when the target is first detected), multiple (triggered after a specified number of detections).

According to controllability, they are distinguished: uncontrollable and controlled from the shore by wire or from a passing ship (usually acoustically).

Based on selectivity, mines were divided into: conventional (hit any detected target) and selective (capable of recognizing and hitting targets of given characteristics).

Depending on their carriers, mines are divided into ship mines (dropped from the deck of ships), boat mines (fired from torpedo tubes of a submarine) and aviation mines (dropped from an airplane).

When laying sea mines, there were special ways to install them. So under mine jar meant an element of a minefield consisting of several mines placed in a cluster. Determined by the coordinates (point) of the production. 2, 3 and 4 min cans are typical. Larger jars are rarely used. Typical for deployment by submarines or surface ships. Mine line- an element of a minefield consisting of several mines laid linearly. Determined by the coordinates (point) of the beginning and direction. Typical for deployment by submarines or surface ships. Mine strip- an element of a minefield consisting of several mines placed randomly from a moving carrier. Unlike mine cans and lines, it is characterized not by coordinates, but by width and direction. Typical for deployment by aircraft, where it is impossible to predict the point at which the mine will land. The combination of mine banks, mine lines, mine strips and individual mines creates a minefield in the area.

Naval mines were one of the most effective weapons during World War II. The cost of producing and installing a mine ranged from 0.5 to 10 percent of the cost of neutralizing or removing it. Mines could be used both as an offensive weapon (mining enemy fairways) and as a defensive weapon (mining one’s own fairways and installing anti-landing mines). They were also used as a psychological weapon - the very fact of the presence of mines in the shipping area already caused damage to the enemy, forcing them to bypass the area or carry out long-term, expensive mine clearance.

During World War II, more than 600 thousand mines were installed. Of these, Great Britain dropped 48 thousand by air into enemy waters, and 20 thousand were dropped from ships and submarines. Britain laid 170 thousand mines to protect its waters. Japanese aircraft dropped 25 thousand mines in foreign waters. Of the 49 thousand mines installed, the United States dropped 12 thousand aircraft mines off the coast of Japan alone. Germany deposited 28.1 thousand mines in the Baltic Sea, the USSR and Finland – 11.8 thousand mines each, Sweden – 4.5 thousand. During the war, Italy produced 54.5 thousand mines.

The Gulf of Finland was the most heavily mined during the war, in which the warring parties laid more than 60 thousand mines. It took almost 4 years to neutralize them.

Depth charge- one of the types of weapons of the Navy, designed to combat submerged submarines. It was a projectile with a strong explosive enclosed in a metal casing of cylindrical, spherocylindrical, drop-shaped or other shape. A depth charge explosion destroys the hull of a submarine and leads to its destruction or damage. The explosion is caused by a fuse, which can be triggered: when a bomb hits the hull of a submarine; at a given depth; when a bomb passes at a distance from a submarine not exceeding the radius of action of a proximity fuse. A stable position of a spherocylindrical and drop-shaped depth charge when moving along a trajectory is given by the tail unit - the stabilizer. Depth charges were divided into aircraft and shipborne ones; the latter are used by launching jet depth charges from launchers, firing from single-barrel or multi-barrel bomb launchers, and dropping them from stern bomb releasers.

The first sample of a depth charge was created in 1914 and, after testing, entered service with the British Navy. Depth charges found widespread use in the First World War and remained the most important type of anti-submarine weapon in the Second.

The operating principle of a depth charge is based on the practical incompressibility of water. A bomb explosion destroys or damages the hull of a submarine at depth. In this case, the energy of the explosion, instantly increasing to a maximum in the center, is transferred to the target by the surrounding water masses, through them destructively affecting the attacked military object. Due to the high density of the medium, the blast wave along its path does not significantly lose its initial power, but with increasing distance to the target, the energy is distributed over a larger area, and accordingly, the damage radius is limited. Depth charges are distinguished by their low accuracy - sometimes about a hundred bombs were required to destroy a submarine.

Floating mines

Until now, we have been talking about mines that precisely “know” their place under water, their combat post, and are motionless at this post. But there are also mines that move, float either under water or on the surface of the sea. The use of these mines has its own combat meaning. They do not have minreps, which means they cannot be trawled with conventional trawls. You can never know exactly where and where such mines will come from; this is discovered at the last moment, when the mine has already exploded or appears very close. Finally, such mines, set adrift and entrusted to the sea waves, can “meet” and hit enemy ships on their way far from the place of deployment. If the enemy knows that floating mines have been placed in such and such an area, this hampers the movements of his ships, forces him to take special precautions in advance, and slows down the pace of his operations.

How does a floating mine work?

Any body floats on the surface of the sea if the weight of the volume of water displaced by it is greater than the weight of the body itself. Such a body is said to have positive buoyancy. If the weight of the volume of displaced water were less, the body would sink and its buoyancy would be negative. And finally, if the weight of a body is equal to the weight of the volume of water it displaces, it will occupy an “indifferent” position at any sea level. This means that it itself will remain at any sea level and will neither rise up nor fall down, but only move at the same level with the current. In such cases, the body is said to have zero buoyancy.

A mine with zero buoyancy would have to remain at the depth to which it was immersed when dropped. But such reasoning is correct only in theory. On the. In fact, at sea, the degree of buoyancy of the mine will change.

After all, the composition of water in the sea is not the same in different places, at different depths. In one place there are more salts in it, the water is denser, and in another there are less salts in it, its density is less. The temperature of the water also affects its density. And the water temperature changes at different times of the year and at different hours of the day and at different depths. Therefore, the density of sea water, and with it the degree of buoyancy of the mine, is variable. More dense water will push the mine upward, and in less dense water the mine will go to the bottom. It was necessary to find a way out of this situation, and the miners found this way out. They arranged the floating mines in such a way that their buoyancy only approaches zero, it is zero only for water in a certain place. Inside the mine there is an energy source - an accumulator or battery, or a reservoir of compressed air. This energy source powers the motor that rotates the mine’s propeller.

Floating mine with propeller

1 - screw; 2 - clock mechanism; 3 - camera for battery; 4 - drummer

The mine floats under the current at a certain depth, but then it fell into denser water and was pulled upward. Then, as a result of the change in depth, the hydrostat, which is ubiquitous in mines, begins to work and turns on the motor. The mine's screw rotates in a certain direction and pulls it back to the same level at which it floated before. What would happen if the mine could not stay at this level and went downwards? Then the same hydrostat would force the motor to rotate the screw in the other direction and raise the mine to the depth specified during installation.

Of course, even in a very large floating mine it is impossible to place such an energy source so that its reserve would last for a long time. Therefore, a floating mine “hunts” its enemy - enemy ships - for only a few days. These few days she is “in waters where enemy ships could collide with her. If a floating mine could stay at a given level for a very long time, it would eventually float into such areas of the sea and at such a time when its ships could get on it.

Therefore, a floating mine not only cannot, but should not serve for long. The miners supply it with a special device equipped with a clock mechanism. As soon as the period for which the clock mechanism is wound has passed, this device drowns the mine.

This is how special floating mines are designed. But any anchor mine can suddenly become floating. Its minerep can break off, fray in the water, rust will corrode the metal, and the mine will float to the surface, where it will rush with the current. Very often, especially during the Second World War, warring countries deliberately laid surface-floating mines on the likely routes of enemy ships. They pose a great danger, especially in poor visibility conditions.

An anchor mine, which has involuntarily turned into a floating mine, can give away the place where the barrier is placed and can become dangerous for its ships. To prevent this from happening, a mechanism is attached to the mine that sinks it as soon as it floats to the surface. It may still happen that the mechanism does not work and the broken mine will swing on the waves for a long time, turning into a serious danger for any ship that collides with it.

If the anchor mine was deliberately turned into a floating one, then in this case it is not allowed to remain dangerous for a long time; it is also equipped with a mechanism that sinks the mine after a certain period of time.

The Germans also tried to use floating mines on the rivers of our country, launching them downstream on rafts. An explosive charge weighing 25 kilograms is placed in a wooden box at the front of the raft. The fuse is designed in such a way that the charge explodes when the raft collides with any obstacle.

Another floating river mine is usually cylindrical in shape. Inside the cylinder is a charging chamber filled with 20 kilograms of explosives. The mine floats underwater at a depth of a quarter of a meter. A rod rises upward from the center of the cylinder. At the upper end of the rod, just at the very surface of the water, there is a float with whiskers sticking out in all directions. The whiskers are connected to a percussion fuse. A long camouflage stem, willow or bamboo, is released from the float onto the surface of the water.

River mines are carefully disguised as objects floating along the river: logs, barrels, boxes, straw, reeds, grass bushes.

From the book Secret Cars of the Soviet Army author Kochnev Evgeniy Dmitrievich

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From the book Underwater Strike author Perlya Zigmund Naumovich

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From the book Armored personnel carriers and armored vehicles of Russia author Gazenko Vladimir Nikolaevich

Mines that “hear” (acoustic mines) Even before German planes took off from their airfields in occupied Greece to land troops on the island of Crete, fascist air destroyers often “visited” this area of ​​the Mediterranean Sea and dropped mines on

From the book Warships author Perlya Zigmund Naumovich

“Sighted” mines All mines, both anchor and bottom, ordinary contact and non-contact (magnetic, acoustic), - they are all “blind” and do not recognize which ship is passing over them. Whether a friendly or enemy ship will touch the mine fuse, its antenna, or pass close

From the book Underground Storm author Orlov Vladimir

How bottom mines “deceive” Minesweeper ships cope well with anchor mines. But they are powerless against bottom mines, magnetic, acoustic and magnetic-acoustic. After all, these mines do not have mines, there is nothing to grab them and pull them out or hook them. They lie at the bottom and there

From the book Japanese Armored Vehicles 1939 - 1945 author Fedoseev Semyon Leonidovich

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Chapter VI Floating airfields Battle across hundreds of kilometers Almost in the middle of the sea route from Japan to America are the Hawaiian Islands. They stretch in a giant chain from west to east. The length of the chain is more than 2500 kilometers. At its eastern end, on the island of Honolulu,

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MINES AND COUNTERMINES After people invented gunpowder, the underground mine war became fierce. In 1552, Tsar Ivan the Terrible besieged the city of Kazan. Russian troops captured the Kazan-Ka River, cutting off the Tatars from water. From a defector, the Tsar learned that the Tatars were fetching water in the dungeon to

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From the author's book

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From the author's book

FLOATING TANKS "TYPE 3" AND "TYPE 5" On the basis of the "Chi-he" in 1943, the amphibious tank "Type 3" ("Ka-chi") with a 47-mm cannon and two machine guns was developed. The shape of the pontoons and the casing above the commander's dome is the same as that of the Ka-mi. The engine exhaust pipes are raised to the roof of the hull. In total there were

German aircraft bottom mine LMB
(Luftmine B (LMB))

(Information on the mystery of the death of the battleship "Novorossiysk")

Preface.

On October 29, 1955, at 1 hour 30 minutes, an explosion occurred in the Sevastopol roadstead, as a result of which the flagship of the Black Sea Fleet, the battleship Novorossiysk (formerly Italian Giulio Cezare), received a hole in the bow. At 4:15 a.m., the battleship capsized and sank due to the unstoppable flow of water into the hull.

The government commission that investigated the causes of the death of the battleship named the most likely cause an explosion under the bow of the ship of a German sea-bottom non-contact mine of the LMB or RMH type, or simultaneously two mines of one or another brand.

For most researchers who have studied this problem, this version of the cause of the event raises serious doubts. They believe that an LMB or RMH type mine, which could possibly lie at the bottom of the bay (divers in 1951-53 discovered 5 LMB type mines and 19 RMH mines), did not have sufficient power, and its explosive device could not lead to mine to explosion.

However, opponents of the mine version mainly point out that by 1955 the batteries in the mines were completely discharged and therefore the explosive devices could not go off.
In general, this is absolutely true, but usually this thesis is not convincing enough for supporters of the mine version, since opponents do not consider the characteristics of mine devices. Some of the supporters of the mine version believe that for some reason, the clock devices in the mines did not work as expected, and on the evening of October 28, being disturbed, they went off again, which led to the explosion. But they also do not prove their point of view by examining the design of the mines.

The author will try to describe as fully as possible today the design of the LMB mine, its characteristics and methods of activation. I hope that this article will bring at least a little clarity to the causes of this tragedy.

WARNING. The author is not an expert in the field of sea mines, and therefore the material below should be treated critically, although it is based on official sources. But what to do if experts in naval mine weapons are in no hurry to introduce people to German naval mines.
A dedicated land traveler had to take on this matter. If any of the maritime specialists deems it necessary and possible to correct me, then I will be sincerely glad to make corrections and clarifications to this article. One request is not to refer to secondary sources (works of fiction, memoirs of veterans, someone's stories, justifications of naval officers involved in the event). Only official literature (instructions, technical descriptions, manuals, memos, service manuals, photographs, diagrams).

German seaborne, aircraft-launched mines of the LM (Luftmine) series were the most common and most frequently used of all non-contact bottom mines. They were represented by five different types of mines installed from aircraft.
These types were designated LMA, LMB, LMC, LMD, and LMF.
All these mines were non-contact mines, i.e. for their operation, direct contact of the ship with the target sensor of a given mine was not required.

The LMA and LMB mines were bottom mines, i.e. after being dropped they fell to the bottom.

The LMC, LMD and LMF mines were anchor mines, i.e. Only the mine’s anchor lay on the bottom, and the mine itself was located at a certain depth, like ordinary sea mines of contact action. However, the LMC, LMD and LMF mines were placed at a depth greater than the draft of any ship.

This is due to the fact that bottom mines must be installed at depths not exceeding 35 meters, so that the explosion could cause significant damage to the ship. Thus, the depth of their application was significantly limited.

Non-contact anchor mines could be installed at the same sea depths as conventional contact anchor mines, having the advantage over them that they can be placed not at a depth equal to or less than the drafts of ships, but much deeper and thereby complicate their trawling .

In the Sevastopol Bay, due to its shallow depths (within 16-18 meters to the silt layer), the use of LMC, LMD and LMF mines was impractical, and the LMA mine, as it turned out back in 1939, had an insufficient charge (half as much as in LMB) and its production was discontinued.

Therefore, to mine the bay the Germans used only LMB mines from this series. No other types of mines of this series were found either during the war or in the post-war period.

LMB mine.

The LMB mine was developed by Dr.Hell SVK in 1928-1934 and was adopted by the Luftwaffe in 1938.

There were four main models - LMB I, LMB II, LMB III and LMB IV.

The LMB I, LMB II, LMB III mines were practically indistinguishable from each other in appearance and were very similar to the LMA mine, differing from it in their greater length (298 cm versus 208 cm) and charge weight (690 kg versus 386 kg).

The LMB IV was a further development of the LMB III mine.
First of all, it was distinguished by the fact that the cylindrical part of the mine body, excluding the explosive device compartment, was made of waterproof plasticized pressed paper (press paper). The hemispherical nose of the mine was made of bakelite mastic. This was dictated partly by the characteristics of the experimental explosive device "Wellensonde" (AMT 2), and partly by a shortage of aluminum.

In addition, there was a variant of the LMB mine with the designation LMB/S, which differed from other options in that it did not have a parachute compartment, and this mine was installed from various watercraft (ships, barges). Otherwise, she was no different.

However, only mines with aluminum casings were found in Sevastopol Bay, i.e. LMB I, LMB II or LMB III, which differed from each other only in minor design features.

The following explosive devices could be installed in the LMB mine:
* magnetic M1 (aka E-Bik, SE-Bik);
* acoustic A1;
* acoustic A1st;
* magnetic-acoustic MA1;
* magnetic-acoustic MA1a;
* magnetic-acoustic MA2;
* acoustic with low-tone circuit AT2;
* magnetohydrodynamic DM1;
* acoustic-magnetic with low-tone circuit AMT 1.

The latter was experimental and there is no information about its installation in mines.

Modifications of the above explosive devices could also be installed:
*M 1r, M 1s - modifications of the M1 explosive device, equipped with devices against trawling by magnetic trawls
* magnetic M 4 (aka Fab Va);
* acoustic A 4,
* acoustic A 4st;
* magnetic-acoustic MA 1r, equipped with a device against trawling by magnetic trawls
* modification of MA 1r under the designation MA 1ar;
* magnetic-acoustic MA 3;

Main characteristics of the LMB mine:

Frame	-aluminum or pressed damask
Overall dimensions:	-diameter 66.04 cm.
	- length 298.845 cm.
Total mine weight	-986.56 kg.
Weight of explosive charge	-690.39 kg.
Type of explosive	hexonite
Explosive devices used	-M1, M1r, M1s, M4, A1, A1st, A4, A4st, AT1, AT2, MA1, MA1a, Ma1r, MA1ar, MA2, MA3, DM1
Additional devices used	-clock mechanism for bringing the mine into firing position types UES II, UES IIa
	-timer self-liquidator type VW (may not be installed)
	-timer neutralizer type ZE III (may not be installed)
	-non-neutralization device type ZUS-40 (may not be installed)
	-bomb fuse type LHZ us Z(34)B
Installation methods	- parachute drop from an airplane
	-dropping from a watercraft (LMB/S mine option)
Mine application depths	- from 7 to 35 meters.
Target detection distances	-from 5 to 35 meters
Mine use options	- unguided bottom mine with a magnetic, acoustic, magnetic-acoustic or magnetic-barometric target sensor,
Time to bring into combat position	-from 30 min. up to 6 hours in 15 minutes. intervals or
	-from 12 o'clock up to 6 days at 6-hour intervals.
Self-liquidators:
hydrostatic (LiS)	- when lifting a mine to a depth of less than 5.18 m.
timer (VW)	- in time from 6 hours to 6 days with 6-hour intervals or not
hydrostatic (LHZ us Z(34)B)	-if the mine after being dropped did not reach a depth of 4.57m.
Self-neutralizer (ZE III)	-after 45-200 days (may not have been installed)
Multiplicity device (ZK II)	- from 0 to 6 ships or
	- from 0 to 12 ships or
	- from 1 to 15 ships
Mine tamper protection	-Yes
Combat work time	- determined by the serviceability of the batteries. For mines with acoustic explosive devices from 2 to 14 days.

Hexonite is a mixture of hexogen (50%) with nitroglycerin (50%). More powerful than TNT by 38-45%. Hence the mass of the charge in TNT equivalent is 939-1001 kg.

LMB mine design.

Externally, it is an aluminum cylinder with a rounded nose and an open tail.

Structurally, the mine consists of three compartments:

*main charge compartment, which houses the main charge, bomb fuse LHZusZ(34)B, clock for bringing the explosive device into firing position UES with hydrostatic self-destruction device LiS, hydrostatic mechanism for switching on the intermediate detonator and device for inactivating the bomb fuse ZUS-40..
On the outside, this compartment has a yoke for suspension to the aircraft, three hatches for filling the compartment with explosives and hatches for the UES, bomb fuse and mechanism for activating the intermediate detonator.

*explosive device compartment in which the explosive device is located, with a multiplicity device, a timer self-liquidator, a timer neutralizer, a non-neutralization device and a tamper-evident device.

*parachute compartment, which houses the stowed parachute. The terminal devices of some explosive devices (microphones, pressure sensors) go into this compartment.

UES (Uhrwerkseinschalter). The LMB mine used clock mechanisms for bringing the mine into firing position of the UES II or UES IIa types.

The UES II is a hydrostatic clock mechanism that begins timing only if the mine is at a depth of 5.18 m or more. It is turned on by the activation of the hydrostat, which releases the anchor mechanism of the watch. You should know that the UES II clock mechanism will continue to operate even if the mine is removed from the water at this time.
UES IIa is similar to UES II, but stops working if the mine is removed from the water.
The UES II is located under the hatch on the side surface of the mine on the opposite side to the suspension yoke at a distance of 121.02 cm from the nose. The diameter of the hatch is 15.24 cm, secured with a locking ring.

Both types of UES could be equipped with a hydrostatic LiS (Lihtsicherung) anti-recovery device, which short-circuited the battery to an electric detonator and exploded the mine if it was raised and it was at a depth of less than 5.18 m. In this case, the LiS could be connected directly to the UES circuit and was activated after the UES had completed its time, or through a forecontact (Vorkontakt), which activated the LiS 15-20 minutes after the start of the UES operation. LiS ensured that the mine could not be raised to the surface after it was dropped from the craft.

The UES clock mechanism can be preset to the required time to bring the mine into firing position, ranging from 30 minutes to 6 hours at 15-minute intervals. Those. the mine will be brought into firing position after being reset in 30 minutes, 45 minutes, 60 minutes, 75 minutes,......6 hours.
The second option for UES operation is that the clock mechanism can be pre-set for the time it takes to bring the mine into firing position within the range from 12 hours to 6 days at 6-hour intervals. Those. the mine will be brought into firing position after being reset in 12 hours, 18 hours, 24 hours,......6 days. Simply put, when a mine hits water to a depth of 5.18 m. or deeper, the UES will first work out its delay time and only then will the process of setting up the explosive device begin. Actually, the UES is a safety device that allows its ships to safely move near the mine for a certain time known to them. For example, during ongoing mining work in the water area.

Bomb fuze (Bombenzuender) LMZ us Z(34)B. Its main task is to detonate the mine if it does not reach a depth of 4.57.m. until 19 seconds have elapsed since touching the surface.
The fuse is located on the side surface of the mine at 90 degrees from the suspension yoke at 124.6 cm from the nose. Hatch diameter 7.62cm. secured with a retaining ring.
The design of the fuse has a clock-type timer mechanism, which opens the inertial weight 7 seconds after the safety pin is removed from the fuse (the pin is connected by a thin wire to the aircraft's release device). After the mine touches the surface of the earth or water, the movement of the inertial weight triggers a timer mechanism, which after 19 seconds triggers the fuse and explodes the mine, if the hydrostat in the fuse does not stop the timer mechanism before this moment. And the hydrostat will only work if the mine by that moment reaches a depth of at least 4.57 meters.
In fact, this fuse is a mine self-destructor in case it falls on the ground or in shallow water and can be detected by the enemy.

Non-neutralization device (Ausbausperre) ZUS-40. The ZUS-40 non-neutralization device can be located under the fuse. It is intended to The enemy diver was unable to remove the LMZusZ(34)B fuse, and thereby make it possible to lift the mine to the surface.
This device consists of a spring-loaded striker, which is released if you try to remove the LMZ us Z(34)B fuze from the mine.

The device has a firing pin 1, which, under the influence of a spring 6, tends to move to the right and pierce the igniter primer 3. The movement of the firing pin is prevented by a stopper 4, resting on the bottom of a steel ball 5. The non-destructive device is placed in the side ignition cup of the mine under the fuse, the detonator of which fits into the socket of the non-destructive device . The striker is moved to the left, as a result of which the contact between it and the stopper is broken. When a mine hits water or soil, the ball flies out of its socket, and the stopper, under the action of spring 2, falls down, clearing the way for the striker, who is now restrained from puncturing the primer only by the fuse detonator. When the fuse is removed from the mine by more than 1.52 cm, the detonator leaves the liquidator socket and finally releases the striker, which pierces the detonator cap, the explosion of which explodes a special detonator, and from it the main charge of the mine explodes.

From the author. Actually, the ZUS-40 is a standard non-neutralization device used in German aerial bombs. They could be equipped with most high-explosive and fragmentation bombs. Moreover, the ZUS was installed under a fuse and a bomb equipped with it was no different from one that was not equipped with one. In the same way, this device could be present in the LMB mine or not. A few years ago, an LMB mine was discovered in Sevastopol, and when trying to dismantle it, two home-grown deminers were killed by the explosion of the mechanical guard of the explosive device (GE). But only a special kilogram charge worked there, which was designed specifically to shorten excessive curiosity. If they had begun to unscrew the bomb fuse, they would have saved their relatives from having to bury them. Explosion 700 kg. hexonite would simply turn them into dust.

I would like to draw the attention of all those who like to delve into the explosive remnants of war to the fact that yes, most German capacitor-type bomb fuses are no longer dangerous. But keep in mind that under any of them there may be a ZUS-40. And this thing is mechanical and can wait for its victim indefinitely.

Intermediate detonator switch. Placed on the opposite side of the bomb fuse at a distance of 111.7 cm. from the nose. It has a hatch with a diameter of 10.16 cm, secured with a locking ring. The head of its hydrostat protrudes onto the surface of the side of the mine next to the bomb fuse. The hydrostat is locked by a second safety pin, which is connected with a thin wire to the aircraft's release device. The main task of the intermediate detonator switch is to protect against a mine explosion in case of accidental activation of the explosive mechanism before the mine reaches depth. When the mine is on land, the hydrostat does not allow the intermediate detonator to connect to the electric detonator (and the latter is connected by wires to explosive device) and if the explosive device is accidentally triggered, only the electric detonator will explode. When the mine is dropped, simultaneously with the safety pin of the bomb fuse, the safety pin of the intermediate detonator switch is pulled out. Upon reaching a depth of 4.57 meters, the hydrostat will allow the intermediate detonator to connect with the electric detonator.

Thus, after separating the mine from the aircraft, the safety pins of the bomb fuse and the intermediate detonator switch, as well as the parachute pull pin, are removed using tension wires. The parachute cap is dropped, the parachute opens and the mine begins to descend. At this moment (7 seconds after separation from the aircraft), the bomb fuse timer opens its inertial weight.
At the moment the mine touches the surface of the earth or water, the inertial weight due to impact with the surface starts the bomb fuse timer.

If after 19 seconds the mine is not deeper than 4.57 meters, then the bomb fuse detonates the mine.

If the mine has reached a depth of 4.57 m before the expiration of 19 seconds, then the timer of the bomb fuse is stopped and the fuse does not take part in the operation of the mine in the future.

When the mine reaches a depth of 4.57 m. The hydrostat of the intermediate detonator switch sends the intermediate detonator into connection with the electric detonator.

When the mine reaches a depth of 5.18 m. The UES hydrostat starts its clockwork and the countdown begins until the explosive device is brought into firing position.

In this case, after 15-20 minutes from the moment the UES clock starts operating, the LiS anti-recovery device may turn on, which will detonate the mine if it is raised to a depth of less than 5.18 m. But depending on the factory presets, LiS may not be turned on 15-20 minutes after starting the UES, but only after the UES has completed its time.

After a predetermined time, the UES will close the explosive circuit to the explosive device, which will begin the process of bringing itself into a firing position.

After the main explosive device has brought itself into a combat position, the mine is in a combat alert position, i.e. waiting for the target ship.

The impact of an enemy ship on the sensitive elements of the mine leads to its explosion.

If the mine is equipped with a timer neutralizer, then depending on the set time in the range from 45 to 200 days, it will separate the power source from the electrical circuit of the mine and the mine will become safe.

If the mine is equipped with a self-liquidator, then, depending on the set time within up to 6 days, it will short-circuit the battery to the electric detonator and the mine will explode.

The mine can be equipped with a device to protect the explosive device from opening. This is a mechanically actuated discharge fuse, which, if an attempt is made to open the explosive device compartment, will detonate a kilogram charge of explosives, which will destroy the explosive device, but will not lead to the explosion of the entire mine.

Let's look at explosive devices that could be installed in an LMB mine. All of them were installed in the explosive device compartment at the factory. Let us immediately note that it is possible to distinguish which device is installed in a given mine only by the markings on the body of the mine.

M1 Magnetic Explosive Device (aka E-Bik and SE-Bik). This is a magnetic non-contact explosive a device that responds to changes in the vertical component of the Earth's magnetic field. Depending on the factory settings, it can respond to changes in the north direction (magnetic lines of force go from the north pole to the south), to changes in the south direction, or to changes in both directions.

From Yu. Martynenko. Depending on the place where the ship was built, or more precisely, on how the slipway was oriented according to the cardinal points, the ship forever acquires a certain direction of its magnetic field. It may happen that one ship can safely pass over a mine many times, while another is blown up.

Developed by Hartmann & Braun SVK in 1923-25. M1 is powered by an EKT battery with an operating voltage of 15 volts. The sensitivity of the early series device was 20-30 mOe. Later it was increased to 10 mOe, and the latest series had a sensitivity of 5 mOe. Simply put, M1 detects a ship at distances from 5 to 35 meters. After the UES has worked for a specified time, it supplies power to M1, which begins the process of tuning to the magnetic field that is present in a given place at the time the A.L.A (a device built into M1 and designed to determine the characteristics of the magnetic field and accept them for zero value).
The M1 explosive device in its circuit had a vibration sensor (Pendelkontakt), which blocked the operation of the explosive circuit when the mine was exposed to disturbing influences of a non-magnetic nature (impacts, jolts, rolling, shock waves of underwater explosions, strong vibrations from working mechanisms and ship propellers working too closely). This ensured the mine's resistance to many minesweeping measures of the enemy, in particular to minesweeping using bombing, pulling anchors and cables along the bottom.
The M1 explosive device was equipped with a VK clock spring mechanism, which, when assembling the mine at the factory, could be set to work out time intervals from 5 to 38 seconds. It was intended to prevent the detonation of an explosive device if the magnetic influence of a ship passing over a mine stopped before a specified period of time. When the M1 mine's explosive device reacts to a target, it causes the clock solenoid to fire, thus starting the stopwatch. If magnetic influence is present at the end of the specified time, the stopwatch will close the explosive network and detonate the mine. If the mine is not detonated after approximately 80 VK operations, it is switched off.
With the help of VK, the insensitivity of the mine to small high-speed ships (torpedo boats, etc.) and magnetic trawls installed on aircraft was achieved.
Also inside the explosive device was a multiplicity device (Zahl Kontakt (ZK)), which was included in the electrical circuit of the explosive device, which ensured that the mine exploded not under the first ship passing over the mine, but under a certain one.
The M1 explosive device used multiplicity devices of types ZK I, ZK II, ZK IIa and ZK IIf.
All of them are driven by a clock-type spring drive, the anchors of which are controlled by electromagnets. However, the mine must be brought into firing position before the electromagnet that controls the anchor can begin to operate. Those. the program for bringing the M1 explosive device into firing position must be completed. A mine explosion could occur under the ship only after the multiplicity device had counted the specified number of ship passes.
The ZK I was a six-step mechanical counter. I took into account triggering pulses lasting 40 seconds or more.
Simply put, it could be configured to pass from 0 to 6 ships. In this case, the change in the magnetic field should have lasted 40 seconds or more. This excluded the counting of high-speed targets such as torpedo boats or aircraft with magnetic trawls.
ZK II was a twelve-step mechanical counter. It took into account triggering pulses lasting 2 minutes or more.
ZK IIa was similar to ZK II, except that it took into account triggering pulses lasting not 2, but 4 minutes or more.
ZK IIf was similar to ZK II, except that the time interval was reduced from two minutes to five seconds.
The electrical circuit of the M1 explosive device had a so-called pendulum contact (essentially a vibration sensor), which blocked the operation of the device under any mechanical influences on the mine (moving, rolling, shocks, impacts, blast waves, etc.), which ensured the mine’s resistance to unauthorized influences. Simply put, it ensured that the explosive device was triggered only when the magnetic field was changed by a passing ship.

The M1 explosive device, being brought into firing position, was triggered by an increase or decrease in the vertical component of the magnetic field of a given duration, and the explosion could occur under the first, second,..., twelfth ship, depending on the ZK presets..

Like all other magnetic explosive devices, the M1 in the explosive device compartment was placed in a gimbal suspension, which ensured a strictly defined position of the magnetometer, regardless of the position in which the mine lay on the bottom.

Variants of the M1 explosive device, designated M1r and M1s, had additional circuits in their electrical circuit that provided increased resistance of the explosive device to magnetic mine trawls.

Production of all M1 variants was discontinued in 1940 due to unsatisfactory performance and increased battery power consumption.

Combined explosive device DM1. Represents an M1 magnetic explosive device
, to which a circuit with a hydrodynamic sensor is added that responds to a decrease in pressure. Developed by Hasag SVK in 1942, however, production and installation in mines began only in June 1944. For the first time, mines with DM1 began to be installed in the English Channel in June 1944. Since Sevastopol was liberated in May 1944, the use of DM1 in mines installed in Sevastopol Bay is excluded.

Triggers if within 15 to 40 sec. after M1 has registered the target ship (magnetic sensitivity: 5 mOe), the water pressure decreases by 15-25 mm. water column and remains for 8 seconds. Or vice versa, if the pressure sensor registers a decrease in pressure by 15-25 mm. water column for 8 seconds and at this time the magnetic circuit will register the appearance of the target ship.

The circuit contains a hydrostatic self-destruct device (LiS), which closes the explosive circuit of the mine if the latter is raised to a depth of less than 4.57 meters.

The pressure sensor with its body extended into the parachute compartment and was placed between the resonator tubes, which were used only in the AT2 explosive device, but in general were part of the wall of the explosive device compartment. The power source is the same for the magnetic and barometric circuits - an EKT type battery with an operating voltage of 15 volts.

M4 Magnetic Explosive Device (aka Fab Va). This is a non-contact magnetic explosive device that responds to changes in the vertical component of the Earth's magnetic field, both north and south. Developed by Eumig in Vienna in 1944. It was manufactured and installed in mines in very limited quantities.
Powered by a 9 volt battery. The sensitivity is very high 2.5 mOe. It is put into operation like the M1 through the UES armament watch. Automatically adjusts to the magnetic field level present at the mine release point at the time the UES ends operation.
In its circuit it has a circuit that can be considered a 15-step multiplicity device, which before installing the mine can be configured to pass from 1 to 15 ships.
No additional devices providing non-removal, non-neutralization, periodic interruption of work, or anti-mine properties were built into the M4.
Also, there were no devices that determined the duration of changes in magnetic influence. The M4 triggered immediately when a change in the magnetic field was detected.
At the same time, M4 had high resistance to shock waves of underwater explosions due to the perfect design of the magnetometer, which was insensitive to mechanical influences.
Reliably eliminated by magnetic trawls of all types.

Like all other magnetic explosive devices, the M4 is placed inside a compartment on a gimbal suspension, which ensures the correct position regardless of the position the mine occupies when it falls to the bottom. Correct, i.e. strictly vertical. This is dictated by the fact that magnetic power lines must enter the explosive device either from above (northern direction) or from below (south direction). In a different position, the explosive device will not even be able to adjust correctly, let alone react correctly.

From the author. Obviously, the existence of such an explosive device was dictated by the difficulties of industrial production and the sharp weakening of the raw material base during the final period of the war. The Germans at this time needed to produce as many of the simplest and cheapest explosive devices as possible, even neglecting their anti-mine properties.

It is unlikely that LMB mines with an M4 explosive device could have been placed in the Sevastopol Bay. And if they were installed, then they were probably all destroyed by mine trawls during the war.

Acoustic explosive device A1 ship. The A1 explosive device began to be developed in May 1940 by Dr. Hell SVK and in mid-May 1940 the first sample was presented. It was put into service in September 1940.

The device responded to the noise of the ship's propellers increasing to a certain value with a frequency of 200 hertz, lasting more than 3-3.5 seconds.
It was equipped with a multiplicity device (Zahl Kontakt (ZK)) of type ZK II, ZK IIa, ZK IIf. More information about the ZK can be found in the M1 explosive device description.

In addition, the A1 explosive device was equipped with a tamper-evident device (Geheimhaltereinrichtung (GE) also known as Oefnungsschutz)

The GE consisted of a plunger switch that kept its circuit open when the explosive compartment cover was closed. If you try to remove the cover, the spring plunger is released during the removal process and completes the circuit from the main battery of the explosive device to a special detonator, detonating a small 900-gram explosive charge, which destroys the explosive device, but does not detonate the main charge of the mine. The GE is brought into firing position before the mine is deployed by inserting a safety pin, which completes the GE circuit. This pin is inserted into the body of the mine through a hole located 135° from the top of the mine at 15.24 cm. from the side of the tail hatch. If the GE is installed in an enclosure, this hole will be present on the enclosure, although it will be filled and painted over so as not to be visible.

Explosive device A1 had three batteries. The first is a 9-volt microphone battery, a 15-volt blocking battery, and a 9-volt ignition battery.

The A1 electrical circuit ensured that it would not operate not only from short sounds (shorter than 3-3.5 seconds), but also from sounds that were too strong, for example, from the shock wave of depth charge explosions.

The variant of the explosive device under the designation A1st had a reduced sensitivity of the microphone, which ensured that it would not be triggered by the noise of acoustic mine trawls and the noise of the propellers of small ships.

The combat operation time of the A1 explosive device from the moment it is turned on ranges from 50 hours to 14 days, after which the microphone power battery fails due to the exhaustion of its capacity.

From the author. I would like to draw the readers' attention to the fact that the microphone battery and blocking battery are constantly in operation. There is no absolute silence underwater, especially in harbors and ports. The microphone transmits all the sounds it receives to the transformer in the form of alternating electric current, and the blocking battery, through its circuit, blocks all signals that do not meet the specified parameters. The operating current ranges from 10 to 500 milliamps.

Acoustic explosive device A4. This is an acoustic explosive device that responds to the noise of the propellers of a passing ship. It began to be developed in 1944 by Dr.Hell SVK and at the end of the year the first sample was presented. It was adopted for service and began to be installed in mines at the beginning of 1945.

Therefore, encounter A4 in LMB mines. installed in the Sevastopol Bay is impossible.

The device responded to the noise of the ship's propellers increasing to a certain value with a frequency of 200 hertz, lasting more than 4-8 seconds.

It was equipped with a multiplicity device of the ZK IIb type, which could be installed for the passage of ships from 0 to 12. It was protected from the noise of underwater explosions due to the fact that the relays of the device responded with a delay, and the noise of the explosion was abrupt. It was protected from simulators of propeller noise installed in the bow of the ship due to the fact that the noise of the propellers had to increase evenly over 4-8 seconds, and the noise of the propellers emanating simultaneously from two points (the noise of real propellers and the noise of the simulator) gave an uneven increase .

The device had three batteries. The first is for powering the circuit with a voltage of 9 volts, the second is for powering the microphone with a voltage of 4.5 volts, and the third is a blocking circuit with a voltage of 1.5 volts. The microphone's quiescent current reached 30-50 milliamps.

From the author. Here too I would like to draw the attention of readers to the fact that the microphone battery and the blocking battery are constantly in operation. There is no absolute silence underwater, especially in harbors and ports. The microphone transmits all the sounds it receives to the transformer in the form of alternating electric current, and the blocking battery, through its circuit, blocks all signals that do not meet the specified parameters.

The A4st explosive device differed from the A4 only in its reduced sensitivity to noise. This ensured that the mine did not detonate against unimportant targets (small, low-noise vessels).

Acoustic explosive device with low-frequency circuit AT2. This is an acoustic explosive device that has two acoustic circuits. The first acoustic circuit reacts to the noise of the ship's propellers at a frequency of 200 hertz, similar to the A1 explosive device. However, the activation of this circuit led to the inclusion of a second acoustic circuit, which responded only to low-frequency sounds (about 25 hertz) coming directly from above. If the low-frequency circuit detected low-frequency noise for more than 2 seconds, then it closed the explosive circuit and an explosion occurred.

AT2 was developed in 1942 by Elac SVK and Eumig. Began use in LMB mines in 1943.

From the author. Official sources do not explain why the second low-frequency circuit was required. The author suggests that in this way a fairly large ship was identified, which, unlike small ones, sent quite strong low-frequency noises into the water from powerful heavy ship engines.

In order to capture low-frequency noise, the explosive device was equipped with resonator tubes that looked similar to the tail of aircraft bombs.
The photograph shows the tail section of an LMB mine with the resonator tubes of the AT1 explosive device extending into the parachute compartment. The parachute compartment cover has been removed to reveal the AT1 with its resonator tubes.

The device had four batteries. The first is for powering the primary circuit microphone with a voltage of 4.5 volts and the electric detonator, the second is with a voltage of 1.5 volts to control the low-frequency circuit transformer, the third is 13.5 volts for the filament circuit of three amplifying radio tubes, the fourth is 96 anode at 96 volts for powering the radio tubes.

It was not equipped with any additional devices such as multiplicity devices (ZK), anti-extraction devices (LiS), tamper-evident devices (GE) and others. Triggered under the first passing ship.

The American Handbook of German Naval Mines OP1673A notes that mines with these explosive devices tended to detonate spontaneously if they found themselves in areas of bottom currents or during severe storms. Due to the constant operation of the normal noise contour microphone (underwater at these depths is quite noisy), the combat operation time of the AT2 explosive device was only 50 hours.

From the author. It is possible that it was precisely these circumstances that predetermined that of the very small number of samples of German naval mines from the Second World War, now stored in museums, the LMB / AT 2 mine is in many. True, it is worth remembering that the LMB mine itself could be equipped with a LiS anti-detachment device and a ZUS-40 anti-neutralization device under the bomb fuse LHZusZ(34)B. It could, but apparently quite a few mines were not equipped with these things.

If the microphone was exposed to the shock wave of an underwater explosion, which is characterized by a very rapid increase and short duration, a special relay reacted to the instantly increasing current in the circuit, which blocked the explosive circuit for the duration of the passage of the blast wave.

Magnetic-acoustic explosive device MA1.
This explosive device was developed by Dr. Hell CVK in 1941, and entered service in the same year. The operation is magnetic-acoustic.

After dropping the mine, the process of working out the delay time with the UES clock and adjusting to the magnetic field that exists in a given place is completely similar to that in the M1 explosive device. Actually, MA1 is an M1 explosive device, with the addition of an acoustic circuit. The process of turning on and setting up is specified in the description of turning on and setting up the M1 explosive device.

When a ship is detected by a change in the magnetic field, the ZK IIe multiplicity device counts one pass. The acoustic system does not take part in the operation of the explosive device at this time. And only after the multiplicity device has counted 11 passes and registered the 12th ship, the acoustic system is connected to work.

Now, if within 30-60 seconds after the magnetic detection of the target the acoustic stage registers the noise of the propellers, lasting several seconds, its low-frequency filter will filter out frequencies greater than 200 hertz and the amplification lamp will turn on, which will supply current to the electric detonator. Explosion.
If the acoustic system does not register the noise of the screws, or it turns out to be too weak, then the bimetallic thermal contact will open the circuit and the explosive device will return to the standby position.

Instead of a ZK IIe multiplicity device, an interrupting clock (Pausernuhr (PU)) can be built into the explosive circuit. This is a 15-day electrically controlled on-off clock designed to operate the mine in a firing and safe position on 24-hour cycles. Settings are made in intervals that are multiples of 3 hours, for example, 3 hours on, 21 hours off, 6 hours on, 18 hours off, etc. If the mine does not go off within 15 days, then this clock is taken out of the circuit and the mine will go off during the first passage of the ship.

In addition to the hydrostatic LiS device built into the UES watch, this explosive device is equipped with its own hydrostatic LiS, which is powered by its own 9-volt battery. Thus, a mine equipped with this explosive device is capable of exploding when raised to a depth of less than 5.18 meters from one of the two LiS.

From the author. The amplification tube consumes significant current. Especially for this purpose, the explosive device contains a 160-volt anode battery. The second 15-volt battery powers both the magnetic circuit and the microphone, and the multiplicity device or interrupting clock PU (if installed instead of the ZK). It is unlikely that batteries that are constantly in use will retain their potential for 11 years.

A variant of the MA1 explosive device, called MA1r, included a copper outer cable about 50 meters long, in which an electrical potential was induced under the influence of a magnetic linear trawl. This potential blocked the operation of the circuit. Thus, MA1r had increased resistance to the action of magnetic trawls.

A variant of the MA1 explosive device, called MA1a, had slightly different characteristics that ensured that the explosive chain was blocked if a decrease in noise level was detected, rather than a steady noise or an increase in it.

A variant of the MA1 explosive device, called MA1ar, combined the features of MA1r and MA1a.

Magnetic-acoustic explosive device MA2.

This explosive device was developed by Dr. Hell CVK in 1942, and entered service in the same year. The operation is magnetic-acoustic.

After dropping the mine, the process of working out the delay time with the UES clock and adjusting to the magnetic field that exists in a given place is completely similar to that in the M1 explosive device. Actually, the magnetic circuit of the MA2 explosive device is borrowed from the M1 explosive device.

When a ship is detected by a change in the magnetic field, the ZK IIe multiplicity device counts one pass. The acoustic system does not take part in the operation of the explosive device at this time. And only after the multiplicity device has counted 11 passes and registered the 12th ship, the acoustic system is connected to work. However, it can be configured for any number of passes from 1 to 12.
Unlike MA1, here, after the magnetic circuit is triggered when the twelfth target ship approaches, the acoustic circuit is adjusted to the current noise level, after which the acoustic circuit will issue a command to detonate a mine only if the noise level has risen to a certain level in 30 seconds. The explosive circuitry blocks the explosive circuit if the noise level exceeds a predetermined level and then begins to decrease. This ensured the mine's resistance to trawling by magnetic trawls towed behind a minesweeper.
Those. first, the magnetic circuit registers the change in the magnetic field and turns on the acoustic circuit. The latter registers not just noise, but increasing noise from quiet to a threshold value and issues a command to explode. And if the mine is encountered not by a target ship, but by a minesweeper, then since the minesweeper is ahead of the magnetic trawl, at the moment the acoustic circuit is turned on, the noise of its propellers is excessive, and then begins to subside.

From the author. In this fairly simple way, without any computers, the magnetic-acoustic explosive device determined that the source of the magnetic field distortion and the source of the propeller noise did not coincide, i.e. It is not the target ship that is moving, but the minesweeper, pulling a magnetic trawl behind it. Naturally, the minesweepers involved in this work were themselves non-magnetic, so as not to be blown up by a mine. Embedding a propeller noise simulator into a magnetic trawl does not give anything here, because the noise of the minesweeper's propellers overlaps with the noise of the simulator and the normal sound picture is distorted.

The MA2 explosive device in its design had a vibration sensor (Pendelkontakt), which blocked the operation of the explosive circuit when the mine was exposed to disturbing influences of a non-magnetic nature (impacts, jolts, rolling, shock waves of underwater explosions, strong vibrations from working mechanisms and ship propellers working too closely). This ensured the mine's resistance to many minesweeping measures of the enemy, in particular to minesweeping using bombing, pulling anchors and cables along the bottom.
The device had two batteries. One of them, with a voltage of 15 volts, fed the magnetic circuit, and the entire electrical explosion circuit. The second 96-volt anode battery powered three amplifying radio tubes of the acoustic circuit

In addition to the hydrostatic LiS device built into the UES watch, this explosive device is equipped with its own hydrostatic LiS, which is powered by the main 15-volt battery. Thus, a mine equipped with this explosive device is capable of exploding when raised to a depth of less than 5.18 meters from one of the two LiS.

The MA 3 explosive device differed from the MA 2 only in that its acoustic circuit was set not for 20, but for 15 seconds.

Acoustic-magnetic explosive device with low-tone circuit AMT 1. It was supposed to be installed in LMB IV mines, but by the time the war ended this explosive device was in the experimental stage. Application of this explosion)