Principles and structure of a submarine

Ensuring strength is the most difficult task, and therefore the main attention is paid to it. In the case of a two-hull structure, the water pressure (excess 1 kgf / cm² for every 10 m of depth) assumes a robust housing that has an optimal shape to withstand pressure. The flow is provided by a lightweight body . In a number of cases, with a single-hull design, the robust housing has a shape that simultaneously satisfies both the conditions of resisting pressure and the flow conditions. For example, the hull of the submarine Dzhevetsky , or the British ultra-small submarine X-Craft , had this form.

Durable housing section with frames

Rugged Case (PC)

It contains all the main systems and devices , and often loads, is the basis for the rest of the submarine designs. To ensure survivability, it is divided by waterproof bulkheads into compartments.

If it was solid, deaf, of a simple geometric shape, this would be enough to provide strength, but in practice everything is different: in a submarine you need the neck of manholes, shafts, shafting, valves, and so on - there are plenty of places where the uniformity of the hull is broken. Each of them is a stress concentrator , that is, a weak point. This is where the destruction under load begins. So, in such places, amplifications are needed - additional elements of a set , thickening of the skin . ^[one]

The most important tactical characteristic of submarines, the depth of immersion , depends on how strong the casing is, what pressure it can withstand. Depth determines the stealth and invulnerability of the boat, the greater the depth of immersion, the more difficult it is to detect the boat and the more difficult it is to hit it. The most important working depth is the maximum depth at which the boat can remain indefinitely without the occurrence of residual deformations, and the maximum depth is the maximum depth that the boat can still plunge without breaking, even with residual deformations.

Of course, durability should be accompanied by water resistance. Otherwise, the boat, like any ship, simply cannot sail.

Before going out to sea or before a hike, during a test dive, the strength and tightness of a robust hull are checked on a submarine. Immediately before diving from the boat using a compressor (on diesel submarines - the main diesel engine), air is partially pumped out to create a vacuum. The command "listen in the compartments." At the same time, they monitor the shut-off pressure. If a characteristic air whistle is heard, and / or pressure quickly recovers to atmospheric pressure, the robust housing is leaking. ^[2] After immersion in the positional position, the “look in the compartments” command is issued, and the body and fittings are visually checked for leaks. ^[3]

Lightweight body (LC)

Lightweight body contours provide optimal flow around the design stroke. In the underwater position inside the light body there is water - the pressure inside and outside it is the same and it does not need to be durable, hence its name. Equipment that does not require isolation from outside pressure is located in a light housing: ballast and fuel tanks (on diesel submarines), ASG antennas, steering rods.

Types of housing design

• One-hull : tanks of the main ballast (CHB) are located inside a durable housing. Lightweight body only at the extremities. The elements of the kit, like a surface ship, are inside a sturdy hull. Advantages of this design: saving size and weight, respectively, lower power requirements of the main mechanisms, better underwater maneuverability. Disadvantages: the vulnerability of a strong hull, a small margin of buoyancy, the need to comply with the CBH durable. Historically, the first submarines were single-hull. Most American submarines are also single-hull.

• Double- case (CDB inside the lightweight case, lightweight case completely covers the strong one): for double-case submarines, the elements of the set are usually located outside the durable case in order to save space inside. Advantages: increased buoyancy, more tenacious construction. Disadvantages: an increase in size and weight, complication of ballast systems, less maneuverability, including during immersion and ascent. Most Russian / Soviet boats were built according to this scheme. For them, the standard requirement is to ensure unsinkability during flooding of any compartment and the adjacent Central City Hospital.

• One-and-a-half- hull: (CDB inside the lightweight case, the lightweight case partially covers the durable one). Advantages of one and a half hull submarines: good maneuverability, reduced diving time with a sufficiently high survivability. Disadvantages: less buoyancy, the need to put more systems in a sturdy case. This design was distinguished by medium-sized submarines of the Second World War , for example, German type VII , and the first post-war, for example, the Guppy type, USA.

• Multi- case (several strong cases inside one lung): this design is not typical. The well-known projects are “ Dolfein ” ( Netherlands ), which has three strong hulls inside one lung, and project 941 (“Shark”, USSR), which has two main strong hulls and three compartments connecting them inside one light hull. Some authors attribute project 941 to two-hull ^[4] .

Add-in

The superstructure forms an additional volume above the central cylinder head and / or the upper deck of the submarine, for use in the surface position. It is light, in the underwater position it is filled with water. It can play the role of an additional camera over the Central City Hospital, insuring tanks against emergency filling. It also has devices that do not require water resistance: mooring, anchor, emergency buoys. In the upper part of the tanks are ventilation valves (HV), under them are emergency flaps (AZ). Otherwise, they are called the first and second constipation of the Central City Hospital.

Strong chopping

Mounted on a sturdy housing on top. It is waterproof. It is a gateway to access the submarine through the main hatch, a rescue camera, and often a fighting post. It has an upper and lower hatchway . Mines of periscopes are usually passed through it. The robust deckhouse provides additional unsinkability in the above-water position - the upper deckhouse is high above the waterline , the risk of flooding the submarine with a wave is less, damage to the robust deckhouse does not violate the tightness of the robust case. Under the action under the periscope, the cabin allows you to increase its reach - the height of the head above the body - and thereby increase the periscope depth. Tactically, this is more profitable - urgent immersion from under the periscope is faster.

Felling Guard

Less commonly, a fence for retractable devices . It is mounted around a robust wheelhouse to improve the flow around it and the retractable devices. It also forms a bridge . It is easy.

According to the law of Archimedes , in order for a body to be completely immersed in water, its weight must equal the weight of the water displaced by it. For immersion, the submarine receives ballast - water - in tanks. To float up, the ballast is blown: water is displaced from the tanks by compressed air. When the boat is fully submerged, it changes depth with the help of rudders . Reception or pumping of ballast after this is done only for balancing.

Main Ballast Tanks

The filling of the CSB repays the main buoyancy reserve of submarines, and ensures normal immersion. In order to better control the dive, the CBH are divided into groups: bow , stern and middle , which can be filled or purged independently or simultaneously.

As a rule, the ballast of a submarine is calculated so that with the end groups filled, the boat floats “under the wheelhouse” - in positional position. During normal (non-urgent) diving, the end groups are first filled, the tightness of the hull and landing are checked, then the middle group is filled. During normal ascent, the middle group is blown first.

In the surface position, the boat floats with open Kingston and emergency shuts. Vent valves are closed. The boat is held on the surface by a cushion of air in the Central City Hospital. It is enough to open the ventilation valves, and the supporting water will displace the air - the boat will begin to sink.

At the end of the dive, the ventilation valves close. In normal mode, under the water, the boat floats with open Kingston and emergency flaps. Before emergence, emergency flaps are closed, air is supplied to the tanks. During normal ascent, after supplying a predetermined amount of air, the kingstones also close to avoid air overruns.

Auxiliary Ballast Tanks

In practice, the boat has a residual buoyancy , that is, there is a difference between the volume of the CBH and the volume of water that must be taken for complete immersion. This difference is compensated by auxiliary ballast tanks. The intake or pumping of water into the equalization tank extinguishes the residual buoyancy.

To compensate for the longitudinal displacements of the cargo - and there are always displacements - there are trim tanks - bow and stern. Reception / pumping of auxiliary ballast and its transfer between trim tanks in order to achieve equilibrium of a submerged submarine on an even keel is called trim.

In practice, it is impossible to take into the equalization tank exactly as much so that the boat without a course “freezes” at a constant depth. It is constantly required to take, then pump out the ballast. On modern submarines for this purpose there is an automatic - depth stabilizer . However, its reliability is low, and the range of work is limited. Therefore, setting the depth stabilizer and removing from it is a whole complex of actions, in compliance with the special mode of operation of the boat. ^[five]

When urgent immersion is required, use the quick immersion tank (pulp and paper mill, sometimes called the urgent immersion tank). Its volume is not included in the estimated buoyancy margin, that is, taking ballast into it, the boat becomes heavier than the surrounding water, which helps to “sink” to the depth. After that, of course, the quick immersion tank is immediately purged. It is housed in a rugged case and is rugged.

In a combat situation (including in military service and on a march), immediately after the ascent, the boat takes water to the pulp and paper mill and compensates for its weight by blowing the main ballast - while maintaining some excess pressure in the TsGB. Thus, the boat is in immediate readiness for urgent diving.

Among the most important special tanks are the following.

Torpedo and missile replacement tanks

To save the total load after the exit of torpedoes or missiles from the TA / mines, and to prevent spontaneous ascent, the water that entered them (about a ton for each torpedo, tens of tons for a rocket) is not pumped overboard, but dumped into specially designed tanks. This allows you to not disrupt the work with the Central City Hospital and limit the volume of the surge tank.

If you try to compensate for the weight of torpedoes and missiles at the expense of the main ballast, it should be variable, that is, an air bubble should remain in the Central City Hospital, and it will “walk” (move) —the worst situation for trim. An immersed submarine at the same time practically loses control , in the words of one author, "behaves like a mad horse." ^{[6] [7]} To a lesser extent, this is also true for the surge tank. But most importantly, if you compensate for large loads with it, you will have to increase its volume, which means the amount of compressed air necessary for blowing. And the supply of compressed air on the boat is the most valuable, it is always small and difficult to replenish.

Annular Clearance Tanks

There is always a gap between the torpedo (missile) and the wall of the torpedo tube (mine), especially in the head and tail parts. Before firing, the outer cover of the torpedo tube (mine) must be opened. This can be done only by equalizing the pressure overboard and inside, that is, filling the TA (shaft) with water that communicates with the outboard. But if you let in water directly from behind, the trim will be shot down - right before the shot.

To avoid this, the water needed to fill the gap is stored in special tanks of the annular gap (TsKZ). They are located near TA or mines, and are filled from the surge tank. After that, to equalize the pressure, it is enough to bypass the water from the central heating plant to the TA and open the outboard valve.

Filling and purging tanks, firing torpedoes or rockets, movement and ventilation require energy.

Accordingly, without energy, the boat can not only move, but retain the ability to "swim and shoot" for any length of time. That is, energy and vitality are two sides of the same process.

If with the movement it is possible to choose the solutions traditional for the ship - to use the energy of the burned fuel (if oxygen is enough for this), or the energy of atom splitting, then for actions peculiar only to the submarine, other energy sources are needed. Even a nuclear reactor, which gives an almost unlimited source, has a drawback - it produces it only at a certain pace, and it is very reluctant to change the pace. Trying to get more power from him means risking that the reaction gets out of control - a sort of nuclear mini-explosion.

So, you need some way to store energy, and quickly release as needed. And compressed air from the diving inception remains the best way. His only serious drawback is limited stocks. Air storage cylinders have considerable weight, and the more, the greater the pressure in them. This limits stocks.

Air system

Compressed air is the second most important source of energy on the boat and, secondarily, provides an oxygen supply. With its help, many evolutions are made - from immersion and ascent to the removal of waste from the boat.

For example, it is possible to deal with emergency flooding of compartments by supplying compressed air to them. Torpedoes and missiles are also fired by air - in fact, by blowing TA or mines.

The air system is divided into a system of high pressure air (VVD) with a pressure of 200-400 kg / cm ² (depending on the type of submarine), medium pressure air (VVP) with a pressure of 6-30 kg / cm ² and low pressure air (VND).

The VVD system is among them the main one. It is more profitable to store compressed air under high pressure - it takes up less space and accumulates more energy. Therefore, it is stored in VVD cylinders, and released to other subsystems through pressure reducers.

Replenishment of the Air Force is a long and energy-intensive operation. And of course, it requires access to atmospheric air. Given that modern boats spend most of their time under water, and at the periscope depth they also try not to linger, there are not many opportunities for replenishment. Compressed air has to be literally rationed, and usually the senior mechanic (commander of the BS-5) personally monitors this. Excess carbon dioxide released during breathing is removed from the air in chemical air recovery units ( scrubbers ) included in the ventilation and air recirculation system.

At nuclear submarines, autonomous oxygen generation units for breathing are used by electrolysis of outboard sea water ^{[8] [9]} . This system allows nuclear submarines for a long time (weeks) not to surface to replenish the air supply.

Some modern non-nuclear submarines in Sweden and Japan use a non-volatile Stirling engine powered by liquid oxygen, which is then used for breathing. Submarines equipped with this system can be continuously under water for up to 20 days.

Movement

Movement, or the course of a submarine, is the main consumer of energy. Depending on how surface and underwater travel is provided, all submarines can be divided into two large types: with a separate or with a single engine .

Separate is an engine that is used only for surface or only for underwater travel. A single , respectively, is called an engine that is suitable for both modes.

Historically, the first submarine engine was man. With his muscular strength, he set the boat in motion both on the surface and under water, that is, it was a single engine.

The search for more powerful and long-range engines was directly related to the development of technology in general. He went through a steam engine and various types of internal combustion engines to a diesel engine . But they all have a common drawback - dependence on atmospheric air. Inevitably, separation occurs, that is, the need for a second engine for underwater travel. An additional requirement for submarine engines is the low noise level. The noiselessness of the submarine in the creeping mode is necessary to maintain its invisibility from the enemy when performing combat missions in the immediate vicinity of it.

Traditionally , the electric motor , which is powered by a battery , has been and remains an underwater engine . It is non-volatile, quite safe and acceptable in weight and size. However, there is a serious drawback - the small battery capacity. Therefore, the supply of continuous underwater running is limited. Moreover, it depends on the mode of use. A typical diesel-electric submarine needs to recharge the battery every 300-350 miles of an economic course or every 20-30 miles of a full course. In other words, the boat can go through without recharging 3 or more days at a speed of 2-4 knots or an hour and a half at a speed of more than 20 knots. Since the weight and volume of the diesel submarine are limited, the diesel engine and electric motor act in several roles. A diesel engine can be an engine or a reciprocating compressor if it is rotated by an electric motor. That, in turn, can be an electric generator when it is rotated by a diesel engine, or an engine when it runs on a screw.

So, Project 641 boats have three movement groups, each consisting of a 37D two-stroke 6-cylinder diesel engine manufactured by the Kolomensky Zavod , the main propeller motor (in the side groups - PG-101, in the middle - PG-102) and the propeller. In addition, an electric motor of an economic course is installed in the middle group of movement. Diesels are in the V diesel compartment, electric motors are in the VI electromotor. In pneumatic shafts, tire-pneumatic couplings (ШПМ) are provided - when the movement group operates only on battery charging, the ШПМ between the ГГЭД and the screw is turned off, disconnecting the screw from the engines, when moving on an electric motor, the ШПМ between the diesel and ГГЭД is disconnected, thereby allowing the ГГЭД and the screw to rotate freely with the diesel stopped. Shpm are controlled by medium pressure air (VSP).

There were attempts to create a single combined cycle engine. German Walther submarines used concentrated hydrogen peroxide as fuel. It was too explosive, expensive and unstable for widespread use.

Only with the creation of a nuclear reactor suitable for a submarine did a truly unified engine appear, giving a course in any position for an unlimited time. Therefore, there was a division of submarines into atomic and non-nuclear .

There are submarines with a non-nuclear single engine. For example, Swedish boats of the Nakken type with a Stirling engine . However, they only lengthened the time of the underwater passage, without relieving the boat of the need to float to replenish oxygen reserves. This engine has not yet been widely used.

Electric Power System (EES)

The main elements of the system are generators , converters , storages, conductors and energy consumers.

Since most submarines in the world are diesel-electric, they have characteristic features in the scheme and composition of the EPS. In the classic diesel-electric submarine system, an electric motor is used as a reversible machine , that is, it can consume current for movement, or produce it for charging. In such a system there are:

• The main diesel . It is a surface engine and a generator drive. Also plays a secondary role as a reciprocating compressor .
• Main switchboard (main switchboard). Converts the generator current to a constant charging current of AB or vice versa, and distributes energy to consumers.
• Rowing electric motor (GED). Its main purpose is to work on the screw. It can also play the role of a generator .
• Rechargeable battery (AB). It stores and stores electric energy from the generator, gives it out for consumption when the generator does not work - primarily under water.
• Electrical fittings . Cables , breakers , insulators . Their purpose is to connect the remaining elements of the system, transfer energy to consumers and prevent its leakage.

For such a submarine, the characteristic modes are:

• Screw charging . The diesel on one side rotates the propeller, the diesel on the other runs on the generator, charging the battery.
• Screw flow rate . The diesel on one side rotates the propeller, the diesel on the other runs on a generator that supplies consumers.
• Partial electric movement . Diesel engines work on a generator, part of the energy of which is consumed by an electric motor, the other part goes to charge the battery.
• Full electric movement . Diesel engines operate on a generator, all of the energy of which is consumed by an electric motor.

In some cases, the system still has separate diesel generators (DG) and an electric motor of economic progress (EDEC). The latter is used for a low-noise economical mode of "creeping" to the target.

Since the second half of the 20th century , a tendency has arisen to build diesel-electric boats with full electric propulsion. In this case, the diesel engine does not work on the screw, but only on the generator. The advantages of such a scheme are the constant operation of the diesel engine and the ability to separate the HED and the generator, and use each in its own mode, which increases the efficiency of both, and hence the reserve of underwater travel. In addition, this makes the shafting line shorter and simpler, which means increased reliability. The disadvantage is the double conversion of energy (mechanical to electrical, then vice versa) and the associated losses. But they put up with this, considering the main mode of charging, and not consumption on GED.

On nuclear submarines, where theoretically there is no need for electricity to move, a low-speed propeller motor is often provided, and almost always an emergency diesel generator .

The main problem of storage and transmission of electricity is the resistance of EPS elements. Unlike ground-based units, resistance in conditions of high humidity and equipment saturation of submarines is a highly variable value. One of the constant tasks of the team of electricians is to control the insulation and restore its resistance to the standard.

The second serious problem is the condition of the batteries. As a result of a chemical reaction, heat is generated in them and hydrogen is released . If free hydrogen accumulates in a certain concentration (about 4%), it forms an explosive mixture with oxygen in the air, capable of exploding no worse than a depth bomb. A superheated battery in a tight hold causes a very typical emergency for boats - a fire in the battery pit .

When seawater enters the battery, chlorine is released, which forms extremely toxic and explosive compounds. A mixture of hydrogen with chlorine explodes even from light. Given that the probability of sea water entering the boat’s premises is always high, constant monitoring of the chlorine content and ventilation of the battery pits are required.

In the underwater position, flameless (catalytic) hydrogen afterburning devices — KPH — are used in the compartments of the submarine and the hydrogen afterburning furnace, which are built into the battery ventilation system. Complete removal of hydrogen is only possible by venting the battery. Therefore, on a boat, even in the base, there is a shift in the central post and in the post of energy and survivability (PES). One of its tasks is monitoring the hydrogen content and venting the battery. ^{[10] [11]}

Fuel system

On diesel-electric, and to a lesser extent, on nuclear submarines, diesel fuel is used - solarium. The volume of stored fuel can be up to 30% of the displacement. Moreover, this is a variable margin, which means it represents a serious task when calculating trim.

The solarium is quite easily separated from the sea water by sedimentation, while it practically does not mix, so this scheme is used. Fuel tanks are located at the bottom of the lightweight housing. As fuel is consumed, it is replaced by sea water. Since the density difference between solarium and water is about 0.8 to 1.0, the order of consumption is followed, for example: the bow on the port side, then the stern port on the starboard, then the bow tank on the starboard side, and so on, so that changes in trim are minimal.

On some 5th generation nuclear submarines, a non-volatile Stirling engine powered by liquid oxygen is used as a drive, which is later used for breathing. The system allows you to achieve high stealth, the boat up to 20 days may not rise to the surface.

Drainage system

As the name suggests, it is designed to remove water from the submarine. Consists of pumps ( pomp ), pipelines and fittings. It has drainage pumps for the rapid pumping of large quantities of water, and drainage for its complete removal.

It is based on centrifugal pumps with high performance. Since their supply depends on the back pressure, and therefore falls with depth, there are also pumps, the supply of which does not depend on the back pressure - piston pumps. For example, on a Project 633 submarine, the productivity of drainage facilities on the surface is 250 m³ / h, at a working depth of 60 m³ / h.

Противопожарная система

Противопожарная система ПЛ состоит из подсистем четырёх видов. По сути лодка имеет четыре независимых системы тушения: ^[12]

1. Система объёмного химического пожаротушения (СХП) ;
2. Система воздушно-пенного пожаротушения (ВПЛ);
3. Система водяного пожаротушения;
4. Огнетушители и противопожарное имущество (асбестовое полотно, брезент и т. п).

При этом, в отличие от стационарных, наземных систем, водяное тушение не является основным. Наоборот, руководство по борьбе за живучесть (РБЖ ПЛ), нацеливает на использование в первую очередь объёмной и воздушно-пенной систем. ^[13] Причина этому — большая насыщенность ПЛ оборудованием, а значит, высокая вероятность повреждений от воды, коротких замыканий, выделения вредных газов.

Кроме того, имеются системы предотвращения пожаров:

• система орошения шахт (контейнеров) ракетного оружия — на ракетных ПЛ;
• система орошения боеприпаса, хранящегося на стеллажах в отсеках ПЛ;
• система орошения межотсечных переборок;

Система объёмного химического пожаротушения (ЛОХ)

Лодочная объёмная химическая (ЛОХ) система предназначена для тушения пожаров в отсеках ПЛ (кроме пожаров порохов, взрывчатых веществ и двухкомпонентного ракетного топлива). Основана на прерывании цепной реакции горения при участии кислорода воздуха гасящим агентом на основе фреона. Основное её достоинство — универсальность. Однако запас фреона ограничен, и потому использование ЛОХ рекомендуется только в определённых случаях.

Система воздушно-пенного пожаротушения (ВПЛ)

Воздушно-пенная лодочная (ВПЛ) система предназначена для тушения небольших местных возгораний в отсеках:

• электрооборудования, находящегося под напряжением;
• скопившегося в трюме топлива, масла или других легковоспламеняющихся жидкостей;
• материалов в аккумуляторной яме;
• ветоши, деревянной обшивки, теплоизоляционных материалов.

Рекомендуется при отсутствии объёмного пожара. Цель — сэкономить запас ЛОХ. Может иметь ответвления, предназначенные специально для тушения пожаров в контейнерах (шахтах) ракет.

Система водяного пожаротушения

Система предназначена для тушения пожара в надстройке ПЛ и ограждении рубки, а также пожаров топлива, пролитого на воде вблизи ПЛ. Иными словами, не предназначена для тушения внутри прочного корпуса ПЛ.

Огнетушители и пожарное имущество

Предназначены для тушения возгораний ветоши, деревянной обшивки, электроизоляционных и теплоизоляционных материалов и обеспечения действий личного состава при тушении пожара. Иначе говоря, играют вспомогательную роль в случаях, когда использование централизованных систем пожаротушения затруднено или невозможно.

• Все системы и устройства подводной лодки настолько тесно связаны с живучестью и зависят друг от друга, что всякий, кто допускается на борт хотя бы временно, должен сдать зачёт по устройству и правилам безопасности на ПЛ, включая особенности конкретного корабля, на который получает доступ.
• Переход из отсека в отсек, особенно в подводном положении, возможен только с разрешения вахтенного офицера или вахтенного механика. ^[14]
• Бывший командир БЧ-5 дизельной ПЛ так описывает необычный случай из практики: ^[6]

У меня на «Малютке» служил старшина торпедистов, весом более 120 кг. Однажды, когда воды в дифферентных цистернах не хватило, я производил дифферентовку, командуя: «Товарищ мичман, пройдите, пожалуйста, в первый отсек и сидите там».

• Кормилицин Ю. Н., Хализев О. А. Устройство подводных лодок: Учебник. Том 2. — СПб.: «Элмор», 2009. — 280 с. — ISBN 5-7399-0153-7 .
• Амитин Маркс Беньяминович, Прасолов Сергей Николаевич Устройство подводных лодок — М.: Воениздат МО СССР, 1973.

• Подводные лодки мира и их ТТХ
• Сигналы аварийного состояния подводных лодок