Marine magnetic mines. Submarine mine weapons. Sections of this page

On the evening of November 10, 1916, the ships of the German 10th flotilla, consisting of 11 new destroyers of 1000 tons of displacement, launched in 1915, left Libau, occupied by the Germans, to the open spaces of the Baltic and headed towards the mouth of the Gulf of Finland. The Germans intended to strike at Russian ships. Their destroyers confidently moved forward. With the stupid self-confidence characteristic of the Germans, German officers even in those years did not believe in the strength and skill of the enemy, and mines... it is unlikely that Russian minefields were impenetrable and dangerous.

The darkness of the autumn evening quickly thickened. The destroyers sailed in wake formation and “stretched out in a long straight line. From the lead ship, only the dark silhouettes of the three rear destroyers were visible; the rest seemed to blend into the surrounding darkness.

The first underwater attack hit the Germans at about 21:00. By this time, the three end ships had fallen far behind. The commander of the destroyer flotilla, Witting, knew about this, but still continued to lead his ships forward. And suddenly the radio brought him the first alarming news: the destroyer “V.75” - one of the stragglers - ran into a Russian mine. An underwater strike burst into the ship like a heavy hammer and damaged it so much that there was no point in saving the destroyer; it was time to save the people. As soon as the second destroyer S.57 took on board the crew, V.75 received a second blow, broke into three parts and sank. “S.57” with a double command began to retreat, but then another underwater strike sounded menacingly. The third ship "G.89" had to urgently triple its crew and take on board all the people from "S.57", which went to "catch up" with "V.75".

Freshly impressed by the Russian mine strikes, the commander of “G.89” had no time for bold raids and ordered a return to base.

Thus the end three of the line of German destroyers melted away. The remaining eight continued to move towards the Gulf of Finland. Here the Germans did not meet Russian light forces. Then they entered the bay of the Baltic port and began shelling the city. With this senseless shelling, the Germans expressed their anger at the losses they had suffered.

Having finished shelling, the German destroyers set off on a reverse course. And then again the sea boiled with underwater explosions. The first to hit the V.72 mine. Someone walking near the V.77 removed people from the blown up ship. The commander of this destroyer decided to destroy the V.72 with artillery fire. In the impenetrable darkness of the night, volleys of guns were heard. The lead ship did not figure out what was happening and decided that the tail of the column was attacked by the Russians. Then the leading destroyers made a 180° turn and went to the rescue. Not even a minute had passed before one of them - "G.90" - was hit near the engine room and followed "V.72". Like a frightened wolf pack, the German destroyers rushed in different directions, just to quickly escape from the deadly ring of Russian mines. The “victorious” arrogance disappeared from the German officers; they had no time for victories. At any cost it was necessary to bring at least the surviving ships to their bases. But at 4 o’clock a dull explosion and a waterspout rising above the S.58 notified the flotilla of the loss of the fifth destroyer. The ship was slowly sinking, and around, as if besieging it, not allowing other destroyers to approach, there were formidable Russian mines, spotted from the surface of the water. Only boats from the S.59 managed to penetrate this deadly underwater palisade and remove the crew from the dying ship. Now the expectation of another catastrophe did not leave the Germans. And indeed, after an hour and a half, "S.59" suffered the same fate as "S.58", and after another 45 minutes, "V.76" - the seventh destroyer that died on Russian mines skillfully placed on probable routes of enemy ships.

During the 1,600 days of the First World War, the Germans lost 56 destroyers to mines. They lost one-eighth of this amount on the night of November 10-11, 1916.

During the entire period of the First World War, Russian miners placed about 53,000 mines in the waters of the Baltic and Black Sea. These mines were hidden under water not only near their shores for their protection. Approaching the enemy’s shores, penetrating almost into their very bases, the brave sailors of our fleet littered the coastal waters in the southern Baltic and the Black Sea with mines.

The Germans and Turks did not know peace and security on their own shores, and Russian mines lay in wait for them there. At the exits from the bases, on coastal routes - fairways, their ships took off into the air and sank to the bottom.

Fear of Russian mines constrained the enemy's actions. The enemy's military transportation and combat operations were disrupted and disrupted.

Russian mines worked flawlessly. They killed not only warships, but also numerous enemy transports.

One of the German submarine “aces,” Hashagen, wrote in his memoirs: “At the beginning of the war, only one mine posed a danger - the Russian mine. Not one of the commanders who were “entrusted with England” - and, strictly speaking, we were all like that - willingly went to the Gulf of Finland. “Many enemies - many honor” is an excellent saying. But close to the Russians with their mines, the honor was too great... Each of us, if not forced to do so, tried to avoid “Russian affairs.”

During the First World War, many enemy ships were lost in minefields of Russia's allies. But these successes were not achieved immediately. At the very beginning of the war, the mine weapons of the British and French turned out to be very imperfect. Both of them had to take care of improving the mine equipment of the fleet. But there was no time for study; it was necessary to find a source of ready-made experience, high-tech mine equipment and borrow it. And so two countries, which had powerful, advanced in technology and numerous fleets, had to turn to Russia for help. And the Germans themselves diligently learned from the Russians the art of mine warfare. At all times, Russian naval sailors had mine equipment at a great height - they were not only brave, but also skillful, proactive, and inventive miners. Russian mines were distinguished by their high combat effectiveness, tactics and placement techniques minefields in the Russian fleet they were excellent.

From Russia they sent to England 1000 mines of the 1898 model and mine specialists who taught the British how to create, manufacture mines, how to place them so that they could hit enemy ships without fail. Then, at the request of the British, they were sent our mines of the 1908 and 1912 models. And only after learning from Russian miners, borrowing their rich experience of studying in peacetime and combat use of mines during the war, the British learned to create own samples good mines, learned to use them and, in turn, had a great influence on the progress of mine weapons.

In the second world war The Allied mine weapons turned out to be better, more combat-ready, and more accurate than the German ones, despite all their “new products” advertised by the Germans.

Underwater stockade

(minefield)

Where the North Sea meets the Atlantic Ocean, England and Norway are separated by a very wide passage of water; between their shores is more than 216 miles. Ships pass here freely, without special precautions, in peacetime. This was not the case during the First World War, especially in 1917.

Under the water, along the entire width of the passage, were hidden mines. 70,000 mines in several rows, like a palisade, blocked the passage. These mines were placed by the British and Americans to block the exit to the north for German submarines.

Only one narrow water path was left for the passage of their ships. This underwater “stockade” was called the “great northern barrier.”

It was the largest in terms of the number of mines and the size of the blocked area. In addition to this barrier, both sides erected many others. Underwater “stockades,” entire chains of hundreds and thousands of mines, protected the coastal sea areas of the warring countries and blocked narrow water passages. More than 310,000 of these underwater shells were hidden in the waters of the North, Baltic, Mediterranean, Black and White Seas. More than 200 warships, dozens of minesweepers (ships designed to detect and destroy mines) and about 600 merchant ships were lost in minefields during the First World War.

During World War II, mines became even more important. In the days when these lines are being written, the results of the mine war at sea have not yet been published. But some of the data that has been published in the press allows us to say that both sides made extensive use of improvements in the design of mines, new methods of laying them, and continuously, very actively used mine weapons.

Underwater "stockade"

During the First World War, mines were primarily deployed to protect coastal areas and sea routes. Such barriers were placed in advance, in some cases even before war was declared, at naval positions covering the approaches to their waters. The position for such a minefield was chosen so that it could be defended by both naval ships and coastal artillery.

Thousands of mines were lined up in the lines of such a barrier, which is called “positional”.

One of the positional barriers was erected even before the start of the 1914 war at the entrance to the Gulf of Finland. It was called the “Central Mine Position”, consisted of thousands of mines and was guarded by ships of the Baltic Fleet and coastal batteries. Throughout the war, especially at the beginning, this barrier was updated and expanded.

Minefields that are placed near the coast to prevent enemy ships from approaching and prevent them from landing troops are called defensive.

But there is another type of obstacle in which mines do not seem to protect or attack, but only threaten and by threat force enemy ships to change course, slow down their movements or completely abandon the operation. Sometimes, if the enemy is confused or neglects the threat of these mines, they turn into an attacking force and sink enemy ships. Such barriers are called maneuverable. They are placed at different moments during the battle to make it difficult for enemy ships to maneuver. Maneuver barrier mines should very quickly become dangerous once they are placed.

Very often, mines are also used as weapons for attack - minefields are placed off enemy shores, in foreign waters. Such barriers are called “active”.

During the Second World War, mining enemy waters became one of the most frequently used operations. Aerial minelayers, which appeared in the First World War, made possible the widespread use of active barriers.

Modern aircraft penetrate deep into the rear of enemy states and litter rivers and lakes with mines. They perform operations that cannot be carried out by either surface or submarine ships.

At first, the Allies had to mainly protect their shores with mines in order to prevent the Nazi fleet from carrying out offensive operations. The Red Fleet laid minefields that reliably covered the flanks of the Red Army, which abutted the seas.

An important role was played by English mines, which surrounded the approaches to the British Isles and prevented the Germans from invading England from the sea. In the end, the Nazis had to abandon attacks from the sea; they had no chance of success.

While the Allies defended themselves with mines, the Germans carried out offensive mine operations. They mined the waters off the coast of their opponents, at the exits of their naval bases. They tried to do this later.

But soon the Allies switched from mine defense to mine offensive. There came a turning point in the mine war, around the fall of 1942, when the Allies themselves began to widely lay active minefields off the coast of Germany, lock fascist ships in their bases, and restrict their movement even along coastal fairways.

* * *

How are mines located in an underwater “stockade”? First of all, it depends on the place where the barrier is placed. If you need to block a narrow fairway, where an enemy ship has to stay in a strictly defined direction, it is enough to scatter a small number of mines along its path without particularly precise adherence to any placement order. In such cases, they say that a mine “can” has been laid. If we're talking about about blocking a large water area or a wide passage, then they lay a lot of mines, hundreds and thousands, or even tens of thousands. In this case, they say that a “minefield” has been laid. For such a barrier, there is a certain order for placing mines. And this order depends mainly on which enemy ships the barrage is set against. First of all, you need to decide in advance which hole to place the mines on. If a barrage is placed against large ships sitting deep in the water, the mines can be deepened 8–9 meters below the surface of the water. But this means that small enemy ships with shallow draft will freely pass through the obstacle; they will pass over the mines. The way out of this situation is simple - you need to place mines in a small depression - 4–5 meters or less. Then the mines will be dangerous for both large and small enemy ships. But it can also happen: it is unlikely that small enemy ships will pass through the barrier, but it would be good for your small ships to be able to maneuver in a mined area.

Therefore, miners have to carefully weigh all the features of the combat situation and only then decide on which hole to place mines. And having solved this issue, it is necessary to ensure that the mines are placed exactly at the given recess.

How large are the gaps between mines in an underwater “stockade”? Of course, it would be nice to place mines thicker, so that the likelihood of colliding with mines and hitting a ship passing on the surface would be as high as possible. But this is hampered by one very serious obstacle, which forces us to maintain gaps between mines of at least 30–40 meters. What is this obstacle?

It turns out that mines are bad neighbors to each other. When one of them explodes, the force of the explosion spreads underwater in all directions and can damage the mechanisms of neighboring mines, disabling them or exploding them. It will turn out like this: one mine exploded under an enemy ship - this is good, but neighboring mines immediately exploded or completely failed. The passage seems to have cleared and other enemy ships will be able to pass through the barrier without losses, and this is already bad. This means that it is better to place mines less often, so that the explosion of one of them does not affect the others. And to do this, it is necessary to select in advance the size of the smallest gap between them, so that, on the one hand, the obstacle remains dangerous for enemy ships, and on the other, so that the explosion of one mine does not disarm neighboring sections of the obstacle. This interval is called the mine interval.

Different mine designs are more or less sensitive to the force of the explosion of a neighboring mine. Therefore, for different designs, mines and intervals are chosen differently. Some mines are protected from the influence of a nearby explosion using special devices. But still, the gap between mines varies between 30–40 meters.

How dangerous is such a rare underwater “stockade” for ships?

If a battleship 30–36 meters wide passes over such a barrier, then, of course, it will probably run into a mine and be blown up. What if it is a destroyer or other small warship only 8-10 meters wide? Then two cases are possible. Either the ship goes towards the obstacle so that its course line is perpendicular to the mine line, or the ship's course line is directed at an angle to the mine line. In the first case, there is little chance of hitting the ship, since the width of its hull is 3-4 times less than the gap between the mines, and most likely the ship will slip through the barrier. In the second case, the probability of a collision with a mine depends on the angle between the ship's course line and the mine line - the smaller and sharper this angle, the greater the chance that the ship will run into a mine. It’s not hard to imagine, and even better is to draw a line of mines and a ship that intersects it at an acute angle. That is why, if the miners know exactly in which direction the enemy ships will pass, they place mines at a very small, acute angle to the probable line of their course.

But this direction is not always known. Then the entire barrier placed against small ships in one line will most likely turn out to be useless or very ineffective. To prevent this from happening, against small ships, miners set up a barrier in two or more lines, placing mines in a checkerboard pattern so that each mine of the second line falls between two mines of the first. At the same time, such a safe gap is maintained between the lines so that the explosion of a mine in one line does not cause the explosion of mines in another line and would not put them out of action.

During the Second World War the situation changed. Small ships with shallow draft (torpedo boats, sea “hunters”) began to play a huge role in naval operations. It was against such ships that small mines had to be placed in a very small depression, sometimes 0.5 meters. And yet, such ships often easily passed through minefields.

The Germans began to set up dense barriers of small mines. But Soviet miners learned to cope with this “novelty” of the Nazis, to guide their small ships through German “dense” barriers.

And finally, there is another type of minefield. Two or more mine lines break, drawing an underwater zigzag. Therefore, enemy ships have to overcome not 2-3 lines of mines, but 6-9 such lines. All this applies to those barriers that consist of so-called anchor mines, such mines that are installed on an anchor in one place and at a certain specified depth.

Anchor mines were the most common in the First World War, but they did not lose their importance in the Second World War.

But there are other mines that are located differently under water. These are bottom mines hiding at the bottom of the sea. These mines played a big role in World War II.

There are also floating mines that are placed in the likely path of enemy ships. Most of all, such mines were and are used in maneuverable obstacles.

These three types of mines differ in the method and location of placement under water, but the mines also differ in another important way. Some mines explode only upon direct collision with a ship; they are called “contact” mines. Other types of mines explode even if: the ship passes on a known, sufficient close range. Such mines are called “non-contact” mines. An anchor mine can be “contact” or “non-contact”, this depends on its devices contained in the housing. The same applies to floating mines and bottom mines.

All these mines, their structure, features and differences will be discussed further. But they have one thing in common. These spherical, oval or pear-shaped metal shells lurk at different depths underwater. They guard their area of ​​the sea like invisible sentries. An enemy ship is approaching. A deafening explosion, raising a huge column of water, hits the underwater part of the ship, tearing it apart. Streams of water rush into the hole. No pumps have time to pump out the mass of rushing water. It happens that the ship immediately or after a more or less short time goes to the bottom. It happens that an underwater attack incapacitates him and weakens his resistance to the enemy.

How are mines constructed?

Mine at anchor

The most important, “working” part of the mine is its charge. Long gone are the days when a mine was filled with ordinary black powder. Nowadays, there are special explosives that explode more powerfully than gunpowder. A common “filling” of a mine is an explosive substance - TNT.

A charging chamber filled with explosive is placed inside a metal shell - the body of the mine. The shape of the body can be different: spherical, ovoid, pear-shaped.

At the moment of explosion, the “filling” burns and turns into gases, which tend to expand in all directions and therefore press on the walls of the housing. This pressure instantly increases to a very large value, tears the hull and hits the ship and the surrounding masses of water with a blow of enormous force. If the walls did not offer resistance to gases, their pressure would increase more slowly and the impact force would be much less.

Separate moments of setting an anchor mine using a shtert

This is the first, main role of the mine body. But the same body also serves another very important purpose.

The chamber with the charge must be hidden underwater at a certain depth so that the mine is not noticed from the surface. An enemy ship, passing over a mine, must touch it and cause an explosion.

All mines (except bottom mines), if placed against surface ships, are usually installed at a depth of 0.5 to 9 meters. If a barrier is placed against submarines, mines are installed at different depths, including deep ones. But the chamber with the explosive is heavier than water and cannot by itself float either on the surface of the water or at some level under water. On its own, it would have sunk to the bottom. But this does not happen - the shell of the mine plays the role of a float for it. Inside the shell there are “voids” filled only with air, so that the weight of the water displaced by the mine is greater than the weight of the body with the charge and other devices. Therefore, the mine acquires the property of buoyancy, it will be able to float on the surface of the water.

At the same time, we must remember and know that a mine is not a small or light projectile. The sizes and weights of mines vary. So, for example, the smallest German mine together with the anchor weighs 270 kilograms and contains only 13–20 kilograms explosive. Its body is a ball. The diameter of the ball is only 650 millimeters. The Germans have mines with a diameter of more than a meter and a total weight of more than a ton. In such a mine, the explosive weighs 300 kilograms.

And yet, no matter how large and heavy the mines are, the body holds them well in a given recess.

If a mine is simply immersed in water to a certain level and then released, the sea will immediately push it back to the surface.

But we need the mine to remain under water, so that something holds it in one place and does not allow it to float up. For this purpose, a special anchor is attached to the shell on a steel cable. The anchor falls to the bottom and holds the mine at a given depression and prevents it from floating up. To make it easier to imagine how this happens, let’s watch the laying of a mine from a ship.

It turns out that it depends on the length of the rod. The longer it is, the sooner its weight touches the bottom, the sooner the mine will stop reeling in, the deeper the mine will go into the water. The shorter the pin, the later the view will stop, and the smaller the mine will be deepened. Let's explain this with an example. Our pole length is 4 meters. The weight touched the bottom. This means that the minrep stopped reeling in just at the moment when the anchor was 4 meters from the bottom. The mine at the same moment was still on the surface of the water. Now the anchor begins to pull her down. And since the anchor has 4 meters left to fall, the mine body will plunge into the water by the same 4 meters.

What is the shtert for? It is much easier to measure the minerep of the required length in advance and throw the mine and anchor into the water. The anchor will touch the bottom, and the mine will be positioned at a given depression. But it’s very troublesome every time to check on a map about the depth of the sea in a given place, calculate how long the minrep is needed, and measure it. It is much easier and faster to lay mines when a long minerep, suitable for various depths, is wound on the view. A small cable automatically places the mine on a given recess.

This whole device is very simple and at the same time quite reliable. But there are other, equally simple and at the same time very interesting devices for placing mines on a given recess.

One of these devices is a very simple and interesting mechanism. This mechanism is often found in both mines and torpedoes and performs very important and varied work in these shells. It's called a "hydrostat".

How does a hydrostat work? From above - there is no water pressure on the disk, the spring has unclenched Bottom - water pressure on the disk compressed the spring
Separate moments of setting an anchor mine using a hydrostat 1st position - mine dropped 2nd position - the mine goes to the bottom 3rd position - anchor at the bottom 4th position - the mine floats up, the anchor is in place 5th position - the mine is positioned at a given depression

In any vessel, even an ordinary glass, the liquid presses on the walls and bottom. If we circle with a pencil any area on the wall or bottom of a glass, then this area is pressed by the weight of a column of liquid, the base of which is equal to the area of ​​the circled area, and the height is equal to the distance from the area to the surface of the water. It is clear that the greatest pressure will be on the bottom of the glass.

Now let's assume that our glass is made of metal, and its bottom can move up and down. This glass is empty. Place a compressed spring under the bottom. She will unclench and raise the bottom up. Let's now start pouring water into the glass, more and more. The bottom remains in place, which means that the force of our spring is greater than the weight of the poured water. But the water level rose again, the column of water in the glass increased, and the bottom went down. Such a device is called a hydrostat, and the movable bottom is called a hydrostatic disk (see figure on page 53). For it, you can always choose a spring that will be compressed by the weight of a column of water of a certain height.

A mine with an anchor first goes to the bottom. Then the body with the view connected to it is separated from the anchor using a special mechanism and raised upward, the minrep is unwound from the view. The hydrostat is located right there, near the view. All the time the mine body is being raised, the water pressure is still very high, the hydrostat spring remains compressed, and the disk is motionless. But the shell reached just such a level when the weight of the water column above the hydrostat disk turned out to be less than the force of the spring. The spring begins to decompress, the disk moves upward. A brake is connected to the disc. As soon as the disk begins to move upward, the brake stops the minrep - the body stops at the depth to which the hydrostat is installed.

The same hydrostat had already worked earlier in the mechanism that separated the mine from the anchor at the bottom. The rod that fastens the mine to the anchor is connected to the hydrostat disk. When a mine with an anchor reaches the bottom, the increased water pressure squeezes the hydrostat disk, and thereby moves the fastening rod to the side. The mine is released and floats up.

How does the hydrostat work in a disconnector? Above is a mine connected to an anchor; there is no pressure on the hydrostat; below - a mine with an anchor at the bottom - the pressure on the hydrostat plate has reached such a value that the spring is compressed and the fastening rod is removed - the mine body is separated from the anchor and floats up

Not only the hydrostat can play the role of a disconnector, freeing the mine from the anchor.

The rod connecting the mine to the anchor can be supported by a spring, and so that it does not loosen, insert between it and the stop... a piece of sugar or another substance that dissolves in the will (rock salt). Sugar or salt do not immediately dissolve in water; it takes several minutes. During this time, the mine with an anchor will reach the bottom. And when the sugar completely melts, the spring will unclench so much that it will pull the rod along with it, the mine will free itself from the anchor and float up.

How does a sugar disconnector work? On top - a compressed spring rests on a piece of sugar and holds the mine. Below - sugar dissolved in water, the spring unclenched and released the mine, which floats up

It is also possible to adapt the rod so that the moment its load touches the bottom, a mechanism is triggered that releases the mine.

All these simple devices- with a hydrostat, with dissolving substances, with a stert - they often and successfully work in mine mechanisms and ingeniously solve the most diverse and complex problems; we will meet with them again.

So, the mine is placed on a given depression and lies in wait for enemy ships. Will an enemy ship explode if it simply touches the shell of a mine, even if it hits this shell hard with its hull? No, it won't explode. The explosive filling of the mine has a very valuable property - it is insensitive to shocks and shocks. During transportation of loaded mines, loading them onto a ship, while laying mines, no matter how careful the miners are, shocks and even impacts still occur. If the mines exploded, it would be too dangerous and difficult to use, and many accidents would occur.

How does a simple mechanical fuse work? On the left is the striker before the collision with the ship; on the right - when the ship collides with a mine, the cargo moves away, the striker acts
How does an electric fuse work? When a ship hits a mine, the load shifts, the striker closes the electrical contacts, and an explosion occurs

In addition to tens or hundreds of kilograms of the main explosive, a metal cup with 100–200 grams of a more sensitive explosive is also placed in the mine. This substance is called a “detonator”.

In order for the mine to explode, it is enough to quickly heat the detonator, and the explosion is transmitted to the entire charge.

How to heat the detonator? To do this, just hit the detonator primer. Upon impact, heat develops. It is transferred to the detonator substance, an explosion occurs, which in turn causes the main charge of the mine to explode.

This means that the mine must be arranged in such a way that when it collides with a ship (and in this case the mine receives a very strong blow), something would hit the detonator cap. This is the essence of the device of a percussion-mechanical mine fuse. Inside the mine, the sharp firing pin of the firing pin “targeted” the primer. A special stop prevents the firing pin from hitting the primer. This emphasis is made in the form of a weight on a rod, which is mounted on a hinge. One has only to move the load to the side, and the lever with the striker will do its job; will fall on the capsule, hit it, heat it up, ignite it, explode it. But this requires a strong push, from which the load would shift to the side. This is the shock that occurs when a ship collides with a mine.

Another way to heat up the detonator is to use a ship's collision with a mine. You can connect the detonator to the electric circuit from the battery and arrange the impact mechanism so that when pushed, the load moves away, and the falling lever closes the electric circuit. Then the electric current will heat the conductor, the heat will spread along the conductor, penetrate the detonator and explode it. But where will the current flow from? From the body of the mine, from its upper part, a kind of “whisker” of the mine sticks out in all directions, 5–6 whiskers. These are the so-called “galvanic shock caps”. They are covered with soft lead shells on top. Inside the lead caps are glass vessels. These glass vessels are filled with a special liquid - electrolyte. If you pour such a liquid into a vessel and immerse two different conductors in it, you will get a so-called galvanic element - one of the sources of electric current. In a mine, these two different conductors - the electrodes of the element - are placed separately from the electrolyte, in a special cup. When a ship that hits a mine crushes the cap and breaks glass vessels, the electrolyte is poured into a cup with electrodes. An electric current immediately arises, which flows through the conductors into the electric fuse. At this moment, the circuit is already closed and the developing heat explodes the detonator and the mine itself.

Construction of an anchor mine body. At the top of the shell, “whiskers” stick out in all directions - lead, crushable caps with galvanic elements enclosed in them. These elements are connected by wires to the detonator

There are also mines that do not have dangerous “whiskers”, and yet the explosion is caused by an electric current. When the ship hits a mine, the weight releases the striker lever, the tip of the firing pin falls, not onto the detonator capsule, but onto the glass capsule with electrolyte and breaks it. The liquid is poured into a cup with electrodes, an electric current is generated, which flows through a closed circuit and explodes the mine.

We already know that a mine charge will not explode either from impact or from friction until a fuse is inserted into the shell, until an impact on an enemy ship or even proximity to it causes the mechanism to ignite the detonator to operate. But before the mines begin, the fuse is already inserted and the mine is ready for action. If you handle it carelessly on the deck or touch it at the moment of setting it, if for some reason the glass vessels of the fuse break, and... the ship will become a victim of its own mine. In the past, such cases happened more than once, and this taught miners not only to be careful and skillful in handling mines when laying them, but also to introduce special mechanisms into them that do not allow the mine to explode before a certain time. The design of these mechanisms is as ingenious as all other mine mechanisms.

How do all these devices work? In one place, the electrical circuit of the fuse is interrupted, the contacts are disconnected and they do not close until the sugar or salt melts in the safety mechanism, or the clock mechanism is triggered, or until the hydrostat disk moves from its place.

All this takes time. Until this time has expired, the mine cannot explode either on the deck or near the ship that placed it, even if for some reason the glass vessel breaks.

In the meantime, the ship that laid the mines will have time to emerge into clear water and escape from the danger it has “sown.”

Mine with antenna

We already know about the “Great Northern Barrage” of 1917, when 70,000 mines formed an underwater stockade stretching between the coasts of Scotland and Norway.

This barrier was deployed against German submarines. Therefore, it was not only multi-row - in several lines, but also “multi-storeyed” - rows of mines were placed at different depths. Could such a barrier be considered impassable for enemy submarines? To answer this question, it is best to do a simple arithmetic calculation. The width of the blocked area is 216 miles. If mines were placed every 40 meters in each line, then 10,000 mines would have to be spent on one line. But a submarine is a small ship, 40 meters is a very wide, safe gate for such a ship. This means that one line of mines or even two lines is not enough. You need at least three lines, or even more. And all these mines would constitute only one “floor” of the barrier. And several such floors were needed, one every 10 meters deep. When they calculated how many mines were needed, it turned out that about 400,000 would be needed. Such a number of mines was difficult to produce in short term and, besides, it would take a lot of time to stage them.

Diagram of the device of an anchor antenna mine. The figure also shows the armature structure

The difficulty was very serious; American and English miners persistently invented and looked for a way out of a difficult situation.

How can we ensure that a rarer barrier is impassable, so that one mine works as well as four or five mines?

The answer was very simple. It was necessary to ensure that the mine would explode not only if a ship struck its body and galvanic shock caps, but also if the ship passed close, at some distance. Then there will be no need to place mines so densely; fewer mines will guard the barred area just as well.

One of the American inventors, engineer Brown, solved this problem.

He reasoned something like this: sea water is a solution of salts. You can imagine the ocean or sea as a giant vessel filled with such a “solution.” It is known from physics that if one plate of zinc or copper and another of steel are lowered into such a vessel, then a galvanic current is formed between them. You can put a copper or zinc plate on the mine, then it will serve as one of the electrodes of the galvanic cell. And when the steel mass of the ship passes close to the mine, you will get a second plate, another electrode of the element. Now, if the copper plate of the mine and the steel plate (ship) are connected by electrical conductors to a sensitive device (in technology, such a device is called a “relay”), then the device will close the electrical circuit, current will flow into the detonator and detonate the mine. It is not difficult to connect the mine plate to the relay, but how to connect the steel bulk of the ship to the relay? Brown proposed to equip the mine with conductors - antennas - extending up to the surface of the sea and down to great depths. These antennas lie in wait for a submarine throughout the depths of the sea. As soon as the ship touches the conductor, the circuit will be closed and the mine will explode.

True, the strike will be delivered at some distance from the ship. But a mine explosion is dangerous even for a surface ship at a distance of 5 meters, and for an underwater ship even at a distance of 25 meters.

Therefore, Brown's invention greatly helped the Americans and the British. They managed to block the entire passage between Scotland and Norway and only cost 70,000 mines (instead of 400,000).

Such mines carried out underwater strikes during the Second World War.

The mine's antenna can also be arranged so that it extends not only down and up, but also to the sides, so that it can also act against surface ships.

That this is so can be seen from the design of one “new product” of German miners, which they tried to use against the Soviet fleet. True, this time we are not talking about an electric antenna, but about an ordinary hemp cable, which was assigned the role of a “tentacle” of the mine.

The Germans equipped an ordinary small anchor ball mine with a charge of 40 kilograms of explosive in a special way. In addition to the fuse caps on the upper hemisphere of the mine shell, they equipped the lower part of the shell with two ordinary mechanical contacts.

And from these contactors an ordinary hemp cable extends upward (to the surface of the sea) - the “tentacle” of the mine. It is supported on the water by cork floats, one for every meter of cable length.

German mine with "tentacle"

In the evening twilight and at night it is very difficult to distinguish both the cable and its floats in the water, and during the day they can pass for a floating part of a harmless fishing net.

If the ship runs into a mine and crushes the caps, the charge will explode. If this does not happen, the ship will pass by, but will touch and slightly pull the cable - one of the mechanical contacts will immediately work, and the mine will explode.

And against this new product, our miners quickly found their own means, learned to avoid the “tentacles” of the mine, and neutralize them.

This is how the miners ensured that the mine exploded without a collision with the ship, without direct contact with it. But still contact remained, if not with the mine itself, then with its antenna. What if the ship doesn't touch the antenna? It turned out that Brown's invention only partially solved the problem.

But it was necessary to solve it completely, to ensure that the mine exploded without any contact with the ship, only when it approached. Miners solved this problem in different ways at the end of the First World War, but only in the Second World War did the warring parties widely use new proximity mines.

Magnetic mines

Before the new year, 1940, on the English ship Vernoy, in a solemn atmosphere, King George VI presented awards to five officers and sailors.

The admiral, who presented the recipients to the king, said in his speech: “Your Majesty! You have the honor to present awards to these five officers and sailors as a token of the country's appreciation and respect for their great courage and the high skill they displayed in carrying out combat mission on dismantling, disarmament and unraveling the secrets of the construction of two enemy mines of a completely new type; they successfully completed their task, risking their lives every minute of their lives dangerous work».

What feat did these five officers and sailors accomplish? What did they do to deserve being awarded in such a solemn and warm atmosphere in front of the ranks of their comrades?

On one moonlit night in November 1939, German bombers appeared over the southeast coast of England.

While the air raid sirens howled, while they rushed across the night sky and combed its long beams of searchlights, while they briefly and angrily “barked” anti-aircraft guns, shooting at the air pirates hiding high behind the clouds, a large three-engine German plane flew slowly and low along the coastline. Amid the noise and confusion of the air raid aimed high against the bombers, the plane quietly approached the intended area and... bombs flew into the water. But at that moment, observers of the English coastal defense discovered this air enemy. They were surprised: bombs in this area - it was very strange. It was difficult to understand what the Germans were actually bombing. There were no ships at sea in this place, there were no targets for bombing.

But suddenly the bombs began to disintegrate in the air. Something flew away from them and fell like a stone into the sea. And then it turned out that it was not bombs that were falling further, but some heavy objects suspended from parachutes. They reached the water. You can see the parachute panels still fluttering near the surface. This means that nothing is pulling them rapidly under water; This means that heavy objects separated from the parachutes and sank to the bottom. Observers began to guess... Maybe these are not bombs at all? After all, already in the first two months of the war, many British ships were lost to mysterious mines, in what seemed to be the safest places. Minesweepers walked ahead of the ships, combing the sea. And yet it didn't help. They suspected that these were mines of a special device, magnetic, hiding at the bottom of the sea, that they were delivered by airplanes.

Meanwhile, the second fascist plane turned too close to the shore. The darkness of the night deceived the air bandit; his bombs landed very close to the shore. Observers reported unusual shells to mine specialists on the Vernoy ship. They made tools from non-magnetic material and only then began to disassemble and disarm the suspicious surprise that had fallen from the sky. Why were such precautions needed?

How a destroyer plane drops its new weapon - a magnetic parachute mine. The picture shows the individual positions of the mine during the drop.

Magnetic mines were not news to either the British or the Soviet miners. The British were making such mines at the end of the First World War, and Russian sailors had to deal with magnetic mines back in 1918. Therefore, it was known that such mines explode when any metal object approaches.

The magnetic properties of the steel mass of the ship’s hull were used to construct so-called “induction” fuses in mines. Several turns of conductor connected to a sensitive relay enter the main device of the mine's induction fuse. When a ship passes near such a mine, its steel mass excites a very weak electric current in the conductor, so weak that it cannot detonate the charge. But the strength of this current is sufficient to close the relay contacts - the arrow closes the contact from the battery placed in the mine body to the detonator - the mine explodes.

The conductor turns in the induction fuse are an intermediary between the steel mass of the ship and the relay pointer. It would be even better to do without this intermediary, who in some cases may fail and fail to fulfill his task. It turned out that it is really possible to do without an intermediary conductor... It is enough just to make the relay arrow magnetic. Then the steel mass of the ship, as soon as the relay is in its magnetic field, will force the needle to deflect and close the contacts from the battery to the fuse. Why would such a deviation occur?

The main material for construction modern ships steel serves. Earthly magnetism magnetizes the steel bulk of the ship, turns it into a very powerful magnet, forming its own magnetic field. The magnetic needle in a mine is under the influence of the earth's magnetic field and is located along its magnetic poles. This is the case until a ship appears nearby. The ship's magnetic field distorts the earth's magnetic field, and thereby causes the needle to deviate at some angle; at the same time, the contacts from the battery to the detonator are closed. This is how the idea of ​​constructing a magnetic mine, which caused so much noise at the beginning of the Second World War, was born.

So, five mine specialists from the Vernon, armed with non-magnetic tools, approached the mysterious mines. Their task was extremely difficult and dangerous. They had no idea about the details of the construction of German magnetic mines. Every new nut and screw removed threatened to cause an explosion. At every minute of work, the miners were guarded by a sudden, irresistible danger, death.

For this work, courage alone was not enough. It was necessary to arm this courage with cool, calm, cautious thoroughness. It was necessary not to rush in order to quickly get away from danger, but on the contrary, not to rush in work in order to more accurately sense this danger and neutralize it. The miners acted persistently and methodically. Only one of them worked for the mine. After each disassembly operation, having unscrewed a nut or screw, he walked away from the mine, returned to his comrades, and handed over the removed part to them. This was done so that in the event of a mine explosion during any dismantling operation and the death of one of the miners, the rest would know exactly at what point in the disassembly the explosion occurred, where the secret of the mine was hidden, and how to defeat this hidden death when dismantling the next mine.

So, slowly but surely and persistently mastering the “secrets” of the new underwater weapons, five English miners revealed all its secrets and learned how the German magnetic mine works.

The oka was very similar to an aerial bomb, a huge cigar 2.5 meters long and 0.6 meters in diameter. Her total weight- 750 kilograms, and the explosive charge weighed a little more than 300 kilograms. The body was made of light non-magnetic metal, duralumin. This was done so that the shell of the mine did not have a magnetic effect on the internal mechanism.

The charge (the newest explosive) is placed in the thicker part of the mine body. In the middle part of the body there is a mechanism for exploding the mine - an electric battery. The current of this battery cannot explode the charge because the electrical circuit is interrupted. Where the chain is interrupted, one of its ends is shaped like a magnetic needle. Two springs hold this arrow in one position. But as soon as a metal magnetic object appears near the mine and creates a magnetic field, the force of the springs is overcome and the arrow rotates on the axis until it touches the end of the second part of the chain (at the break point). The circuit will close, current from the battery will flow to the charge and explode it.

A parachute box in the form of two opening cones is placed in the pointed “tail” of the mine. The box contains a parachute with cables on which a mine hangs.

Airplanes equipped for dropping torpedoes are armed with magnetic mines. Only instead of one torpedo, such an aircraft takes with it two mines; they are placed in a chamber at the bottom of the aircraft fuselage. When the mine separates from the aircraft, its parachute box opens and releases the parachute. The parachute opens and lowers the mine onto the water on its cables. The impact on the water is not strong (thanks to the parachute) and the mechanisms do not break. After a mine falls into the water, a special mechanism is triggered, which releases the parachute. The mine sinks to the bottom. At low drop heights, mines are placed without parachutes.

A mine explodes when a ship passes over it and affects it with its magnetic field. A magnetic mine has to be placed at a shallow depth, no more than 20–25 meters, since at greater depths it will not “feel” the ship.

Almost simultaneously with the description of the magnetic bottom mine, information appeared in the press about another type of such weapon, about a pop-up magnetic mine. There are so many interesting and instructive details in the design of the pop-up mine that it is worth getting to know it.

Such a mine is dropped without a parachute at low altitude.

The design of this mine is more complex; it has many new mechanisms, because the pop-up mine faces a more difficult task - to lie in wait for ships at great depths, not in coastal waters, but on sea routes. Up to 120 meters separate such a mine from the surface of the water. When a ship appears nearby, the mine should float up and explode only at a shallow depth - 10–15 meters.

This mine is shaped like a radio tube, magnified 100 times or more. It weighs 400 kilograms and contains 200 kilograms of explosives. The body of this mine is also made of non-magnetic metal. The upper part of the case houses an electric battery, a mechanism with a locked magnetic needle and electrical circuits. In addition, two hydrostats are located here. Their mechanisms operate at a certain depth.

The charge and explosive device are placed in the middle part of the mine. There are two chambers at the bottom. One is intended for ballast water (we will soon find out when and why the mine takes this ballast). The second is filled with compressed air. In addition, the back of the mine body is equipped with tails: this is a stabilizer.

The plane drops a mine from a low altitude (30–60 meters) without a parachute, and it falls with its front part down. The mine touched the water and sank to the bottom. But the disk of one of the hydrostatic devices is adjusted to operate at a depth of 20 meters. As soon as the mine reaches this depth, the disk begins to move and pushes a thin piston, which presses on the adjacent tube; mercury pours out of it into the place where the electrical circuit is interrupted. The circuit closes, and the current from the battery releases the magnetic needle from the fuse.

This mine has three electrical circuits. The first has already worked, but the second and third are still open. While the mine sinks to the bottom, the ballast compartment is filled with water through holes in the tail section. This makes the tail of the mine heavier than its front part - the mine turns over in the water and “sits” on the bottom on its tail. Now the mine is installed and lies in wait for its future victim.

The magnetic needle is very sensitive. When the ship is still a little less than a kilometer away, it begins to oscillate and turn around its axis. The ship is approaching - and the needle is turning more and more. Finally, the moment comes when the arrow touches the contact.

The second circuit will close, but the mine will not explode; after all, an explosion at a depth of 100–120 meters will not harm the ship. Besides, the ship is still far away; it is only approaching that part of the sea surface under which the mine is installed - there is still time for the explosion. Therefore, when the circuit closes, it is not the mine charge that explodes, but a small fuse in the tail section. This small explosion opens the valve of the compressed air tank. With enormous force, the air rushes into the ballast compartment and expels water from there. Mina is getting lighter. When water leaves the ballast compartment, special springs close the holes - more water no longer penetrates the mine. The mine begins to float to the surface. There is less and less water pressure on the disk of the second hydrostat, which has not yet “worked”. At a depth of 10–15 meters, this pressure will decrease so much that the spring will go up and push the disk; the lever connected to the disk will operate and close the third, combat electrical circuit. This time the electric current will charge and detonate the mine.

But where will it explode? Under the ship or to the side of it, in front or behind? These questions are difficult to answer. Of course, the ship will suffer most if a mine explodes under its very bottom. What is needed for this to happen? It is necessary that both the mine and the ship travel the distance to the explosion point at the same time. But the ship may not go in that direction at all, because the ship’s hull can affect the needle if the mine is not in front, but somewhere to the side. If the ship is heading towards a mine, then in this case one can rarely expect a real explosion. The mine goes upward at a speed of 6–7 meters per second; a battleship is approaching it at a speed of, say, 40 kilometers per hour or 11 meters per second; Let's assume that the arrow closes the circuit when the ship is 300 meters from the mine. The mine will reach the explosion point in 17 seconds (approximately), and the ship in 27 seconds. This means the mine will explode in front of the ship, approximately 100 meters away, and will not cause any harm. From this example it is clear that a successful coincidence of the magnitude and strength of the ship’s magnetic field is necessary (this determines at what distance from the ship the magnetic needle will close the contact of the second circuit and the mine will begin to float up) with the direction of the ship’s movement, with its speed and with the depth of installation of the mine. Only in this case the explosion will occur under the bottom or very close to it. Therefore, even if a pop-up magnetic mine were actually used, it would hardly be expected to be particularly successful.

At the beginning of the Second World War, there were many cases of Allied ships being killed by German magnetic mines. We had to urgently look for remedies against the new underwater danger. Such a remedy has been found and is successfully serving its purpose.

How these means are designed and operate, we will talk about this in the chapter about sea workers, about sailors-miners from minesweepers who find and destroy enemy mines.

Mines that “hear”

(acoustic mines)

Even before German planes took off from their airfields in occupied Greece to land on the island of Crete, Nazi air destroyers often “visited” this area of ​​the Mediterranean and dropped mines on the waterways leading to the island. They tried to surround Crete with a mine ring, tighten a deadly noose around the island and cut it off from the main naval bases of the English fleet. All this was done in order to block the path of enemy ships in advance, weaken the defense of the island, and so that at critical moments of the air attack planned by the Germans, the British would not be able to provide assistance to Crete from the sea.

The Germans were unpleasantly surprised when it turned out that British ships regularly supplied the island and suffered negligible losses from mines. It’s as if someone managed to tell the English miners what kind of “traps” awaited them on the approaches to the island, and taught them to avoid dangers. The Nazis especially felt the weakness of their mines when the German transports heading to the island experienced powerful and destructive blows from British ships.

It seemed that the mines dropped by the Germans were powerless against the British ships. And the Nazis pinned special hopes on these mines. By this time, their magnetic mines, one of the types of Hitler’s “mysterious” weapons with which the Germans intended to conquer the world, were well known to the Allies. Allied miners learned to fight German magnetic mines without much loss. And then the Germans decided to unleash a new “unknown” weapon on the Allied ships, a new, seemingly irresistible, mine of enormous destructive power. It was with these mines that the Germans blocked Crete, and yet they were defeated again and again. The new mines caused almost no losses to the enemy. What new mines were these? Their peculiarity was that inside, in the body of the mine, there was a mechanical “ear” - a microphone, the same as in the handset of an ordinary telephone. Very soon the specialists figured out the structure of this mine. It turned out that the mine “hears” the noise of the machines and propellers of the approaching ship.

Moreover, this “hearing” is so subtle that it detects the moment when a ship passes over a mine. Then it explodes at the very bottom of the ship... unless, of course, measures are taken to prevent this from happening.

The device of the “hearing” mine is very interesting.

As with all other mines, the power of its impact lies in the charge. It is very large, much larger than in other mines. The amount of explosive filling the charging compartment of the mine reaches 700–800 kilograms. It is known that a “hearing” mine, or, as experts call it, an acoustic mine, hides on the bottom of the sea off the coast at relatively shallow depths. It explodes at some distance from the bottom of the ship. Therefore, the Germans equipped this mine with almost a ton of explosives, so that the force of its underwater strike, weakened by the thickness of the water, would be sufficient to destroy the ship. The membrane of the mine's mechanical ear is connected to a special oscillating vibrator lever located inside the mine, in the center of its upper part. There is a microphone under the vibrator; as soon as the vibrator touches the microphone, a continuous chain will be created from the shell to its mechanical ear. As long as there is no noise, as long as the “ear” does not “hear” anything, the vibrator is at rest and does not connect to the microphone.

Mine that “hears” (acoustic mine) 1 - ship vehicles; 2 - area of ​​greatest noise; 3 - sound waves; 4 - sound waves vibrate the “ear” of the mine and activate the vibrator; 5 - contact “whiskers”; 6 - another “ear” of the mine; 7 - vibrator; 8 - charge; 9 - microphone; 10 - detonator.

The mine runs on an electric battery. The microphone is always connected to the circuit of this battery, and a small direct current flows through it. The primary winding of the transformer is included in the same circuit. While the mine does not “hear” anything and the vibrator is at rest, the current in the microphone circuit flows harmlessly, not threatening anything.

But a ship is approaching. Sound waves from the noise of cars and propellers diverge in all directions and travel far under water. They reach the membrane - the "eardrum" of the mine's mechanical ear - and begin to vibrate it. At first these fluctuations are small and slow. But the noise gets closer, the sounds intensify, the mine membrane begins to vibrate more and more. The vibrator also vibrates with it. And at the same time, with each vibration, it either touches the microphone, is included in its electrical circuit, then moves away from it, and is disconnected from the circuit. Each switching on causes an increase in the electrical resistance of the microphone, each switching off reduces this resistance. Because of this, the voltage of the direct electric current passing through the microphone circuit and the primary winding of the transformer changes all the time, becoming either less or more. Direct current turns into pulsating current. According to the laws of electrical engineering, an alternating current is excited in the secondary winding of the transformer, and its strength is greater, the “louder” the sounds of noise “heard” by the mine.

The mine also has a current rectifier. The alternating current from the secondary winding of the transformer passes through this rectifier and enters a new electrical circuit composed of two relays.

Meanwhile, the ship is approaching, its noises are intensifying and, along with them, the current in the new electrical circuit is increasing. Finally, the noise reaches a certain level and... the first relay is activated. It closes the contacts and at the same time connects a new special-purpose battery to the winding of the second relay. And within seconds, the increasing noise causes the second relay to operate, which with its contacts forms a “bridge” between the new battery and the mine detonator. Current from the battery rushes through this bridge to the detonator, heats it, ignites it, and thereby explodes the mine. The entire explosive device is timed so that the explosion occurs just under the ship and hits it in the least protected part of the hull, at the bottom.

In addition to acoustic mines, which “hear” the approach of a ship, the Germans also used magnetic-acoustic mines. In these mines, both magnetic and acoustic devices work in the fuse circuit, or rather, the acoustic device seems to help the magnetic one. Such help was needed because a purely acoustic device often failed and worked at the wrong time.

Despite all the tricks of the Germans, their “new unknown weapon” - acoustic mines - was very quickly figured out by the Allies. They soon learned to neutralize them and clear blocked areas of the sea from them. In turn, the Allies managed to create more advanced models of acoustic mines.

"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 touches a mine fuse, its antenna, or passes near a magnetic or acoustic mine, an explosion will still follow. But there are also “sighted” mines that seem to “distinguish” between ships and explode only under enemy ships.

In 1866, when the Austrians fought with the Italians, among the coastal structures near Trieste, not far from its harbor, a small house, camouflaged by trees, was carefully guarded. One of the rooms inside the house, if Italian spies had penetrated it, would have aroused their legitimate curiosity. All the walls of the room were painted thick black. The only window was closed not with ordinary glass, but with optical glass - a lens.

The image of the harbor of Trieste through the lens fell on a glass prism inside the room and was reflected from it down onto the matte surface of a special “observation” table.

Mine "piano" of the Austrians (1866)

Dots were marked on the surface of the table. If the image of the harbor was reflected correctly onto the matte table, each dot represented a location where a mine was hidden under the water. But these were no ordinary anchor mines. An electric wire connected these mines to the mysterious house.

Attached to the observation table was the same keyboard as a grand piano. Each key controlled the explosion of a specific mine. As soon as one or another piano key was pressed, an electric current from the station on the shore immediately ran to the mine and exploded it.

Scheme of station minefields. On the left is a diagram of the barrier, on the right is a diagram of the device of group 1 mines - group of mines; 2 - main cables from the control station to the distribution boxes; 3 - batteries of rapid-fire guns protecting the minefield; 4 - wires from the junction box to the mines; 5 - coastal mine control station; 6 - station mines; 7 - electrical wire from the junction box to the mine; 8 - distribution box; 9 - main station cable

From the picture of the harbor reflected on the frosted glass, the observer could monitor the approach of an enemy ship. As soon as the ship was above the mine, pressing the keys of the mine “piano” sank it.

This device was tested, the “music” of the mine piano was considered very successful, but... the Austrians did not have to use it as military weapon: by this time the Italians had already been defeated in the naval battle of Lisse.

“Sighted” mines were not invented by the Austrians. This weapon originated during civil war in America between northerners and southerners.

A few years before the Battle of Lissa, the southerners used mines that exploded with an electric current “sent” from the shore. The current was turned on when an enemy ship passed over the mine. These were “sighted” mines; it is these mines that should be considered the ancestors of modern “station” mines guarding the naval bases of the warring parties. Since then, the technology for constructing and exploding sighted mines has continuously improved.

How do modern sighted mines protect the shores?

On the shore, somewhere between the rocks or underground, a mine control station is camouflaged. The protected area of ​​the sea is divided into square sections, clearly visible from the shore. Modern stations have neither a keyboard nor a panorama table.

How does a coastal control station for “sighted” mines work?

Instead of a “piano” there is an ordinary control panel with switches, and instead of a panorama there is a periscope, like on a submarine. From the station, the cables stretch to the sea, go under water, wind along the rocky or sandy bottom and crawl into the distribution box.

Several wires are already radiating from the box to the mines guarding a certain square of the sea. These mines are similar to anchor mines, but they can also be bottom mines and are designed so that an electric current turned on from the station explodes the entire group. An enemy ship is approaching. He approaches the mined area, where one of the groups of mines lies in wait for the gate. A few more minutes, and the ship is already above the hidden sighted mines. The “eyes” of these mines are there, on the shore, inside the camouflaged station. From there, through the periscope, everything is clearly visible, and observers accurately catch the moment when they need to detonate the mines. Turning the switch - the electric current from a special coastal power station instantly runs the distance to the distribution box, from there it flows through the wires to the mine fuses and powerful explosion destroys the ship.

What happens if it is not a surface ship that is clearly visible that approaches the protected area, but an enemy submarine that is secretly approaching the shore? The submarine cannot be seen from the station through the periscope, but it will be heard: as soon as the submarine inevitably touches one of the mines or its mine, a signal will sound at the station, and turning the switch will explode exactly that group of mines, near which the invisible one is sliding under water at that moment enemy.

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.

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 artillery department 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

For the first time an electric fuse for " hellish machines"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 mine proved to be excellent marine structures Jacobi and Nobel. 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”.

Sea mines

a weapon (a type of naval ammunition) to destroy enemy ships and hinder their actions. The main properties of mines: constant and long-term combat readiness, surprise of combat impact, difficulty in clearing mines. Mine mines can be installed in enemy waters and off their own coast (see Minefields). A mine is an explosive charge enclosed in a waterproof casing, which also contains instruments and devices that cause a mine to explode and ensure safe handling.

The first, although unsuccessful, attempt to use a floating mine was made by Russian engineers in the Russian-Turkish war of 1768-1774. In 1807 in Russia, the military engineer I. I. Fitzum designed a mine, detonated from the shore using a fire hose. In 1812, the Russian scientist P. L. Schilling implemented a project for a mine that would be exploded from the shore using an electric current. In the 40-50s. Academician B. S. Jacobi invented a galvanic shock mine, which was installed under the surface of the water on a cable with an anchor. These mines were first used during the Crimean War of 1853-56. After the war, Russian inventors A.P. Davydov and others created shock mines with a mechanical fuse. Admiral S. O. Makarov, inventor N. N. Azarov and others developed mechanisms automatic installation mines into a given depression and improved methods of laying mines from surface ships. M. m. were widely used in the First World War of 1914-18. In World War 2 (1939-45), non-contact 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. Airplanes were widely used to lay mines in enemy waters.

M. m., depending on their carriers, are divided into ship-based (thrown from the deck of ships), boat-based (shot from torpedo tubes submarine) and aviation (dropped from an airplane). Based on their position after installation, moths are divided into anchored, bottom, and floating (with the help of instruments they are held at a given distance from the surface of the water); by type of fuses - contact (explode upon contact with a ship), non-contact (explode when a ship passes at a certain distance from the mine) and engineering (explode from a coastal command post). Contact mines ( rice. 1 , 2 , 3 ) there are galvanic impact, shock-mechanical and antenna. The fuse of contact mines has a galvanic element, the current of which (during the contact of the ship with the mine) closes the electrical fuse circuit using a relay inside the mine, which causes an explosion of the mine charge. Non-contact anchor and bottom mines ( rice. 4 ) are equipped with highly sensitive fuses that react to the physical fields of the ship when it passes near mines (changing magnetic field, sound vibrations, etc.). Depending on the nature of the field to which proximity mines react, magnetic, induction, acoustic, hydrodynamic or combined mines are distinguished. The proximity fuse circuit includes an element that senses changes in the external field associated with the passage of a ship, an amplification path and an actuator (ignition circuit). Engineering mines are divided into wire-controlled and radio-controlled. To make it more difficult to combat non-contact mines (mine sweeping), the fuse circuit includes urgency devices that delay bringing the mine into firing position for any required period, multiplicity devices that ensure the mine explodes only after a specified number of impacts on the fuse, and decoy devices that cause the mine to explode while trying to disarm it.

Lit.: Beloshitsky V.P., Baginsky Yu.M., Underwater strike weapons, M., 1960; Skorokhod Yu. V., Khokhlov P. M., Mine defense ships, M., 1967.

S. D. Mogilny.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what “sea mines” are in other dictionaries:

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Sea mines- SEA MINES. They were installed in the water to engage surface water. ships, submarines (submarines) and enemy vessels, as well as difficulties in their navigation. They had a waterproof housing that contained an explosive charge, a fuse and a device that provided... Great Patriotic War 1941-1945: encyclopedia

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Sea mines- one of the types of weapons of the naval forces, designed to destroy ships, as well as to limit their actions. M. m. is a high explosive charge enclosed in a waterproof casing in which ... ... A brief dictionary of operational-tactical and general military terms

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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 the design as completely as possible today LMB mines, 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 various types 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 device.

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 fuse design has a clock-type timer mechanism that 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 the explosion of the mine, if the hydrostat in the fuse does not stop the timer mechanism until 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 at the moment the twelfth target ship approaches, the acoustic circuit is adjusted to the noise level available on this moment, 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)