What is immersion depth. Maximum diving depth of submarines: features and requirements. Depth - salvation or death

Underwater shipbuilding has several goals. All of them, one way or another, are associated with a decrease in the possibility of detecting a submarine by increasing the distance between it and the water surface, as well as some other factors.

Of course, military-industrial complex in general, a special area, the goals of which are often very different from the aspirations of an ordinary peaceful person. However, in the proposed article, we will consider some data on the depth of submersion of submarines, as well as the limits in which this value varies.

A bit of history: bathyscaphe

The material will, of course, be about warships. Although man's exploration of the open spaces of the sea includes even a visit to the planet's maximum depth - the bottom of the Mariana Trench, which, as you know, is more than 11 km from the surface of the oceans. However, the historic dive, which took place back in 1960, was carried out in a bathyscaphe. This is an apparatus that does not have buoyancy in the full sense, since it can only sink and then rise due to the tricks of engineering genius. In general, during the operation of the bathyscaphe, there is no question of moving in a horizontal plane over any serious distances. Therefore, the depth of submersion of submarines, which, as you know, can cover huge distances, is much less than the record for a bathyscaphe, at least for now.

The most important characteristic

Speaking of records in the field of ocean exploration, one should not forget about the true purpose of the submarines. The military targets and payload that are usually carried on such ships does not only imply the highest mobility required for them. In addition, they must skillfully hide in ideally suited water layers, emerge at the right time and descend as quickly as possible to the depth necessary for survival after a military operation. In fact, the latter determines the level of combat capability of the ship. Thus, the maximum immersion depth of a submarine is one of its most important characteristics.

Increase factors

In this regard, there are several considerations. An increase in depth makes it possible to improve the maneuverability of a submarine in the vertical plane, since the length of a warship is usually at least several tens of meters. Thus, if it is 50 meters under water, and its dimensions are twice as large, moving up or down is fraught with a complete loss of disguise.
In addition, in the water column there is such a thing as "thermal layers", which greatly distort the sonar signal. If you go below them, then the submarine becomes practically "invisible" to the tracking equipment of surface ships. Not to mention the fact that at great depths such a device is much more difficult to destroy with any weapon available on the planet.

The greater the submerged depth of submarines, the stronger the hull must be able to withstand incredible pressures. This, again, plays into the hands of the overall defense capability of the ship. Finally, if the depth limit allows you to lay down on the ocean floor, this also increases the invisibility of the submarine for any location equipment at your disposal. modern systems tracking.

Basic terminology

There are two main characteristics that show the ability of a submarine to dive. The first is the so-called working depth. In foreign sources, it also appears as operational. This characteristic shows what is the depth of immersion of submarines, which can be lowered an unlimited number of times over the entire period of operation. For example, the American "Thresher" normally made 40 dives per year within this value, until the next attempt to exceed it tragically died along with the entire crew in the Atlantic. Second the most important characteristic- calculated or destructive (in foreign sources) depth. Corresponds to its value at which the hydrostatic pressure exceeds the strength of the hull, calculated during the design of the device.

Test depth

There is another characteristic that should be mentioned in context. This is the depth of submersion of the submarine, which, according to the calculations, is below which it can cause the destruction of the skin itself, or the frames, or other external equipment. It is also called "test" in foreign sources. In no case should it be exceeded for a particular device.

Returning to the Thresher: with a design value of 300 meters, he went to a test depth of 360 meters. By the way, in the United States, the submarine is sent to this depth immediately after launching from the factory and, in fact, “runs in” on it for a certain time before being transferred to the department ordering it. Let's finish the sad story of Thresher. Tests at 360 meters ended tragically for him, and although this was not caused by the depth itself, but by technical problems with the submarine's nuclear engine, however, the accidents, apparently, are not accidental.

The submarine lost its course due to a motor stop, purging the ballast tanks did not work, and the device went to the bottom. According to experts, the destruction of the submarine's hull occurred at a depth of about 700 meters, so, as we can see, there is still a decent difference between the test value and the really destructive one.

Average figures With the passage of time, naturally, the values of the depths increase. If the submarines of the Second World War were designed for values of 100-150 meters, then subsequent generations raised these limits. With the invention of the possibility of using nuclear fission to create engines, the depth of submersion of nuclear submarines also increased. In the early 60s, it was already about 300-350 meters. Modern submarines have limits of the order of 400-500 meters. While there is clear stagnation on this front, it seems that the matter is for future developments, although mention should be made of an extraordinary project created in the Soviet Union in the 80s.

Absolute record

We are talking about the Komsomolets submarine, which, unfortunately, tragically sank, but it still holds the unconquered peak in the development of the sea depths by modern submarines. This unique project has no analogues in the world yet. The fact is that for the manufacture of its case, a very durable, expensive and extremely inconvenient material in processing was used - titanium. The maximum depth of submersion of a submarine in the world still belongs to Komsomolets. This record was set in 1985 when a Soviet submarine reached 1027 meters below the sea surface.
By the way, the working value for it was 1000 m, and the estimated value was 1250. As a result, Komsomolets sank in 1989 due to a strong fire that started at a depth of about 300 meters. And although he, unlike the same Thresher, managed to surface, the story still turned out to be very tragic. The fire damaged the submarine so much that it sank almost immediately. Several people died in the fire, and about half of the crew drowned in icy water while help arrived.

Conclusion

The immersion depth of modern submarines is 400-500 meters, the maximum usually has somewhat greater values. The record of 1027 meters set by Komsomolets is not yet under the force of any of the submarines in service with all countries. Word for the future

The submersion of a submarine is its transition from a surface position to an underwater one or a change in the depth of immersion from less to more.

The transition of the submarine from the surface to the underwater position is carried out by filling the tanks of the main ballast, and changing the immersion depth from less to more, as a rule, by the course and horizontal rudders.

A two-stage dive of a submarine is commonly referred to as a normal dive. It is produced:

When signboard;

When trimming in areas cramped for maneuvering in a submerged position;

For training purposes, as well as at the discretion of the submarine commander.

During a normal dive, the end tanks of the main ballast are filled first, then middle group with an empty quick-dive tank.

Before diving, the holds are drained on the submarine, the compartments and the battery are ventilated, the bridge is prepared for diving, and when approaching the diving point, the course is stopped and the quick dive tank is purged. The dive is preceded by the command of the submarine commander “All down. In places to stand, to dive. The personnel take places according to the diving schedule, close the outboard openings and prepare the submarine systems for swimming under water. Main command post transferred from the bridge to the central post or to the conning tower. Observation of the horizon is carried out through the periscope and with the help of radio equipment. Then the tanks of the main ballast of the bow and stern (end) groups are filled, and the ventilation of the stern group opens 1-2 seconds earlier than the bow, and the submarine moves into position.

In the positional position, the filling of the drainage line and unloaded torpedo tubes with water is checked, the compartments are inspected to determine the quality of the pressure hull sealing. The roll and trim of the submarine are reduced to zero.

After performing the above actions, the tanks of the main ballast of the middle group are filled. The ventilation valves of these tanks close at a depth of 5-7 m. If the submarine begins to sink rapidly with the beginning of filling the middle group, you should immediately close the ventilation valves of the tanks of the middle group, blow out the "middle", start the pump to pump water out of the equalization tank overboard and emerge position, and then establish and eliminate the cause of the failure of the submarine. Only then repeat the dive. If the submarine does not sink when the middle group is filled, it is considered "light". In this case, the redemption of positive buoyancy is carried out by receiving water from behind the side into the surge tank. With the arrival of the submarine to a depth of no more than the periscope, the ventilation valves of all the tanks of the main ballast are closed.

Normal dive on the go

Arriving at the dive point and switching to the required mode of movement, the submarine commander commands: “All down. In places to stand, to dive. When executing this command, the same actions and in the same order are carried out as when diving without a move. After the command “Fill the middle one”, the commander orders: “Dive so many meters, trim so many degrees.” When diving to a safe or greater depth, it is not recommended to create a trim of more than 5-7 °.

When diving on an even keel, the filling of the main ballast tanks will be more uniform. In this case, the horizontal rudders are shifted "parallel to the dive" in such a way that the trim of the submarine is zero. This situation persists to a depth of about 5-7 m.

With the arrival of the submarine at the specified depth, you can create a trim set by the commander.

If the boat does not sink, water should be taken into the surge tank. In this case, as soon as the depth gauge shows a change in depth, water intake is suspended. If, after filling the middle group of tanks of the main ballast, the submarine begins to sink rapidly, it is necessary to create a trim to the stern, keeping it from further diving with the course and rudders. At the same time, water must be pumped out of the surge tank overboard. If this is not enough, you should partially blow out the middle group of main ballast tanks, pump out the required amount of water from the surge tank, and then, having removed the "bubble" from the "middle one", continue diving.

Urgent dive

An urgent dive is performed by the submarine commander or watch officer and, as a rule, one combat shift. It ensures that the submarine goes under water in a minimum time.

At the command "All down", the personnel on the bridge quickly descend into the boat. On the signal "Urgent dive", the personnel perform the following actions:

Stops diesel engines, disengages nose clutches, seals air supply shafts to diesel engines and other outboard openings, opens pressure equalization valves of main ballast tanks containing fuel, as well as a buoyancy tank ventilation valve;

Closes the upper hatch hatch (pl commander or officer of the watch);

Fills the tanks of the main ballast;

Manages horizontal rudders;

Blows out the fast dive tank and closes its kingstones;

Closes the ventilation valves of the middle group and the main ballast tanks.

During an urgent dive, the middle group of tanks is filled after battening down the hatchway. The control device of the signaling station should show that the wheelhouse hatch, locks of the air supply shaft to diesel engines, ship and battery ventilation are closed.

AT initial period dives of a submarine, the bow horizontal rudders should be put on the dive, and the stern - on the ascent. In this case, both pairs of horizontal rudders create drowning forces. Stern horizontal rudders, creating a trimming moment on the stern, help to keep the boat on an even keel, balancing the trimming moment that appears with the filling of the fast dive tank.

Upon reaching the depth, when all the tanks of the main ballast are full, the stern rudders should be shifted to dive, create a trim of up to 10 ° on the bow (depending on the design of the submarine) and hold it during the dive.

If the submarine must remain at periscope depth, the quick dive tank is purged at a depth equal to half the periscope depth. If it is necessary to go to a safe depth, the fast dive tank is blown at a depth not less than periscope. The ventilation valves of the main ballast tanks are closed immediately after the submarine goes under water.

As a rule, with the “Urgent Dive” command, an order is given by the submarine commander (officer on duty): “Dive to a depth of so many meters with a trim of so many degrees.” With the approach to a given depth, the trim is retracted, and the helmsman-horizontalist reports the depth of immersion using a depth gauge.

During an urgent dive, one must be ready to carry out emergency blowing of the end tanks of the main ballast, if the trim, rapidly increasing, exceeds the allowable one. Blowing out the middle group of tanks may be required in case of loss of buoyancy due to incorrect calculation of the load of the submarine or in case of belated blowing of the fast dive tank.

Dive to the ultimate depth

In a submerged position, the submarine can be located at depths: periscope (7-9 m), under the RDP

Our expert is Vladimir Rodionov, Candidate of Medical Sciences, Head of the HBO Department of the Republican Scientific Center for Chemistry of the Russian Academy of Medical Sciences, Head of the Department of HBO of the RMAPE of the Ministry of Health of the Russian Federation.

Who's new?

Often the decision to dive to the depths comes to tourists spontaneously. For example, when they find themselves in the city to buy souvenirs, and smiling sellers of underwater excursions approach them and offer to make an unforgettable trip to the depths of the sea at ridiculous prices. However, buying a dive certificate at a random excursion shop is a big mistake. Normal diving centers (which belong to the most famous diving associations - PADI, PDA, CMAS) do not contact such intermediaries. Low price excursions should also alert. The third point - when concluding a contract, it is required to fill out a special questionnaire that allows you to find out if a person has any diseases in which diving can be dangerous (first of all, this applies to all acute ailments and most serious chronic diseases, especially pulmonary and cardiovascular pathologies, as well as congenital heart defects).

The first dive, according to all the rules, should take place in the so-called "closed" water: a pool or a bay, and not in the sea ("open" water). There is also a clear safety rule for beginners: a maximum of two clients per instructor. In reality, everything often happens quite differently: tourists are immediately taken out to sea, while the boat is overcrowded, it is not uncommon when there are only 1-2 instructors for 10 inexperienced divers.

Not knowing the ford, do not poke your head into the water

Diving for the first time is allowed to a depth of no more than 10-12 meters, so diving sites in normal centers are chosen very carefully and so that there are no undercurrents. For beginners, when diving to a depth of more than 40 meters, the narcotic effect of nitrogen often manifests itself (the so-called "deep intoxication"). The resulting euphoria often pushes them to inappropriate behavior and, in particular, makes them rise abruptly, without stopping. And under no circumstances should this be done.

When ascending even from a shallow depth, it is important not to exceed the ascent rate of 10-18 m per minute. If you violate the decompression regime (that is, ascent), decompression (or caisson) sickness may develop. Its essence is this. As you dive, nitrogen enters the diver's bloodstream and dissolves there. And with a rapid ascent (under high pressure and with significant air consumption), this gas does not have time to be excreted from the body. As a result, bubbles form in the blood and tissues, which destroy the body. With a mild degree of decompression sickness, pain in the joints and muscles, a feeling of heaviness in the heart, and increased fatigue most often occur. In severe forms, damage to the lung tissue, paralysis and other neurological disorders, up to and including death, are possible.

The French are to blame
Caisson disease is called so by analogy with the invention of the French scientist Triget, who in 1839 patented a caisson (box) for the construction of bridge supports. Since that time, people have been able to stay under high pressure for a relatively long time. Immediately after this invention, many caisson workers died from decompression sickness. But this ailment was known before, long before the invention of the caisson and spacesuit, however, its consequences were less severe, since people without special equipment could not stay under water for a very long time. But nevertheless, for a long time, Japanese ama divers suffered from tarawan disease (from the age of 30, unfortunate women noted unsteadiness of their gait, hand tremors, and memory impairment). The disease is associated with hypoxia and the formation of gas bubbles in the central nervous system during systematic diving.

The French are to blame

Caisson disease is called so by analogy with the invention of the French scientist Triget, who in 1839 patented a caisson (box) for the construction of bridge supports. Since that time, people have been able to stay under high pressure for a relatively long time. Immediately after this invention, many caisson workers died from decompression sickness. But this ailment was known before, long before the invention of the caisson and spacesuit, however, its consequences were less severe, since people without special equipment could not stay under water for a very long time. But nevertheless, for a long time, Japanese ama divers suffered from tarawan disease (from the age of 30, unfortunate women noted unsteadiness of their gait, hand tremors, and memory impairment). The disease is associated with hypoxia and the formation of gas bubbles in the central nervous system during systematic diving.

The intensity of gas formation depends not only on the ascent mode, but also on the individual resistance of a person to decompression sickness. The risk of developing the disease is directly proportional to the time spent under water and at depth. So, with a 6-hour stay at a depth of 7-8 m and a quick ascent, 5% of people fall ill; from 16 m - every second; from a depth of 24 m - almost every person.

And pray that the insurance won't let you down

In order for the dive to be successful, the diver must not only think over the choice of the ascent mode in advance (and strictly follow it underwater), but also be absolutely healthy and rested at that time. Also, he should not smoke and take alcohol and drugs (especially tranquilizers) either before or after the ascent. At first, heavy physical activity should also be avoided - for example, you should not go to the gym in the evening.

It is also dangerous to fly an airplane earlier than a day after a dive (and 72 hours after multiple dives in one day). This exacerbates the development of decompression sickness.

Just in case, you need to find out where the nearest recompression pressure chamber is located, which is necessary for the treatment of decompression sickness. But since 1 hour of operation of this installation costs from $ 700 to 2500, and in severe forms of the disease, continuous treatment may be required for several days, the best way out for a person planning diving is to purchase special medical insurance. For up to 20 days, its cost will be about 30 euros, and for a year it will cost about a hundred euros.

Breathe deeply!

If the victim has developed decompression sickness, it is better to start treatment as soon as possible, and not wait until arriving at home. Moreover, special recompression pressure chambers in which it is possible to install special treatment, in ordinary Russian medical institutions unfortunately not today. The last time such a pressure chamber worked at the Russian Research Center for Chemistry of the Russian Academy of Medical Sciences was in the 1990s, but due to the high cost of its use, it no longer functions.

Therefore, such patients can be treated only in oxygen pressure chambers. The method of hyperbaric oxygen therapy (HBO) is not the most effective in this case, but it is better than nothing.

The meaning of the word "deep" is as difficult to quantify as the height of the word "tall."

Eighteen meters is “high” for a person standing on the ground and “low” for a satellite in orbit. Obviously, the terms "deep" and "high" are subjective. However, physics and physiology can slightly reduce the arbitrary meaning of the word "deep" in recreational diving. In any case, the boundary must be drawn somewhere, if only to make our discussion more meaningful and to understand the peculiarities of diving.

PADI and most members of the recreational diving community define "deep" diving as diving to 18 meters or less, but no deeper than 40 meters. recreational diving, limited time for non-stop diving to depths of more than 18 meters, as well as the intensity and focus of training for recreational divers, setting depth limits is very useful and justified by experience.

Although 40 m is defined as the maximum depth, there are four reasons why in most cases it is necessary to reduce the optimal depth limit to 30 m. First, at depths greater than 30 meters, small no-decompression limits and rapid air consumption make dives very short. Considering the time and effort it takes to plan and execute a deep dive, its program and goal should be completely satisfying and achievable in 10 minutes.

Secondly, at depths of more than 30 meters, most divers are exposed to nitrogen anesthesia. This is nitrogen poisoning that increases with depth. Although the susceptibility to nitrogen in the blood varies from person to person, this is a good enough reason not to go deeper than 30 m.

Thirdly, when diving to depths of more than 30 meters, the chances of getting decompression sickness increase, especially during repeated dives. With only one air tank, at this depth it is very easy to exceed the no-compression limit.

Finally, in many places at depths of more than 30 meters, nothing or almost nothing is visible - the water absorbs light. It is much more difficult to navigate and read instrument readings there - the latter circumstance makes it difficult to control the equipment.

How to Increase Your Personal Depth Limit

Although the diving community defines "deep" dives as deep as 18 meters, you need to decide which dive is "deep" for you personally based on your environment, training and experience. When setting a depth limit for yourself, do not forget about the experience and training of your partner.

Let's say diving to 18 meters will not cause any difficulties if it is done in the warm, transparent oxen of a tropical sea, and you and your buddy are appropriately prepared and have been actively diving all the time. The same dive, but after a break of ten months and without preparation, it will certainly be more difficult and seem more “deep”. The same dive to a depth of less than 18 meters in a cold and dark lake in conditions of poor visibility can be considered “deep” even with the appropriate experience and training.It is clear that the limits of depth vary depending on the circumstances.

When setting your depth limit for a given dive, take into account the conditions in which it is being made, as well as the capabilities of a partner and your own. First, think about the diving conditions. Based on them, what is the real depth limit? Maybe you'd better start with a shallower dive, and then gradually increase the depth? Secondly, decide how prepared you are physically and mentally for diving. Are you in good shape, do you have the necessary experience, do you feel confident? Third, look at how deep you've dived before, what your nitrogen group is, and how long you've been on the surface since your last dive. Check with your dive computer if you have one. On repetitive dives, the no decompression limit decreases, and it limits the depth of your dive (remember that more deep diving done at the beginning). Fourth, evaluate the geographical location of the place where you dive. How quickly will help arrive if something happens to you? Fifth, evaluate the capabilities of your partner using the same criteria. The optimal and safe depth for both of you will be the maximum depth for this dive.

They go deeper

The diving community almost unequivocally accepts 40 meters as the limit for recreational diving, but you've probably heard or read about technical diving people who go lower. This circumstance, however, does not in any way affect the depth limits set for recreational divers.

Having understood the essence of the matter, you will understand that when practicing technical diving, you need to take a lot more equipment underwater: often not one, but four - six cylinders, several regulators, and so on, with an increasingly complex design. Diving to depths of more than 40 meters often requires breathing a special helium mixture, as well as several decompression stops lasting an hour or more. As you understand, this type of diving requires special training and significant prior experience in recreational diving. Even with the right equipment, experience and training, technical diving remains a much riskier activity than recreational diving. When taking into account all additional equipment, special diving techniques and intensive training, which reduce risk in technical diving, exceeding the 40-meter depth limit seems reasonable. Technical diving is not for everyone and is not the next required step even after several thousand recreational dives, but if you are interested in technical diving, you will need to acquire the necessary training and experience before trying.

The quality, uninterrupted supply of water, the life of the device, and sometimes the hydraulic structure itself depend on the depth of immersion of the pump in the well. It is better to entrust the calculation of the minimum installation depth of a borehole pump to specialists. It depends on the flow rate of the source and the performance of the pump. It is necessary to mount the device in such a way as to exclude dry operation. At the same time, the distance from the bottom must be sufficient so that sand and silt are not sucked into the inlet pipe along with water.

Variety of models of submersible pumps

Permissible depth limits for installation of a borehole pump

the device should not come into contact with the bottom of the hydraulic structure;
the device must be immersed at least 1 meter under the water surface.

Why is there a depth limit relative to the water table at all? This is due to the characteristics of the device. Firstly, it is necessary to provide conditions under which it is impossible to work on a "dry run". Secondly, the cooling of the electric motor is carried out at the expense of the working medium. There must be enough water so that the device does not overheat, otherwise it may be difficult to pump the liquid.

The restriction on placement above the bottom exists because suspended solids are most abundant in the near-bottom water layer. This applies to all hydraulic structures, but is especially true for sand wells. In the water there are particles of soil, sand, silt. If you lower the pump too low, it will pump dirty water, unsuitable for drinking and domestic needs. Getting into the pump mechanism, grains of sand can damage it and disable it. Therefore, it is desirable to place the device 2-6 m from the bottom.

Scheme of installing a pump in a well

How to take into account the dynamic level of the well

The dynamic level is the distance from the water surface to the surface of the earth. Take into account the value when the level is minimum. This is important because the amount of water in the well is not constant. It may vary depending on the season, the intensity of water intake from the horizon through hydraulic structures drilled into this reservoir. The dynamic level indicators are indicated in the well passport. They may vary depending on the type and design of the pump. The higher the performance of the pump, the greater should be the depth of its immersion.

A Practical Method for Determining the Right Depth

In practice, the pump is installed in the well as follows:

First, the device is lowered on a safety cable to the entire depth of the water well.
When the device reaches the bottom, it is raised by 1.5-2 m, temporarily fixed.
After that, run to check the work.
If the device is working normally, there are no comments or complaints, it is finally fixed in this position.

Note! The method is used only in cases where the depth of immersion of the pump in the well is up to 16 meters. It is not suitable for deep wells.

Usually our compatriots try to do all the work on their own. Installing water-lifting equipment does not seem too complicated, so many people do it on their own. When installing, remember that errors can result in unplanned repairs or even replacement of the pump. Therefore, if you have any doubts about the correctness of the actions performed, consult a specialist.