The underwater bow of the ship. Benefits of sea water for the nose

The movement along rivers and seas on ships has been known in history for more than five thousand years. Today, according to the generally accepted terminology, a seagoing vessel is a cargo, passenger or commercial large-sized floating craft, a ship is a military one. The list of ships can be long. The most famous marine are sailboats and yachts, passenger liners and steamships, boats, tankers and bulk carriers. Ships are aircraft carriers, battleships, cruisers, destroyers, and submarines.

Ship structure

Whatever type or class the craft belongs to, it has common structural elements. First of all, of course, the hull, on which superstructures for various purposes, masts and deckhouses are installed. Engines and propellers, in general, power plants are an important element of all ships. For the life of the floating craft, devices, systems, electrical equipment, pipelines and equipment of the premises are important.

Equipped with spars and rigging.

The bow is called the front, the stern is the rear end of the hull, its lateral surfaces are the sides. The sailors call the starboard side in the direction of travel the starboard, the left side - the backboard.

The bottom or bottom is the lower part of the ship, decks are horizontal overlaps. The hold of a ship is the lowest space between the bottom and the lower deck. The space between the decks is called a twindeck.

Ship hull design

If we talk about a ship in general, whether it be a warship or a civilian ship, its hull is a streamlined, watertight, hollow body. The hull provides the ship's buoyancy and is the base or platform on which equipment or weapons are mounted, depending on the purpose of the ship.

The type of vessel determines both the shape of the hull and its dimensions.

The ship's hull consists of a set and a skin. Bulkheads and decks are elements specific to certain types of ships.

Sheathing can be made of wood, as in ancient times and today, plastics, welded together or riveted steel sheets, or even reinforced concrete.

On the inside, to maintain the strength and shape of the hull, the skin and deck are reinforced with a set of rigidly fastened beams, wood or steel, which are located in the transverse and longitudinal directions.

At the extremities, the hull most often ends with strong beams: in the stern - with the sternpost, and in the bow - with the stem. Depending on the type of vessel, bow contours can be different. They determine the reduction of resistance to the movement of the vessel, ensuring maneuverability and seaworthiness.

The underwater bow of the ship reduces water resistance, which means that the ship's speed increases and fuel consumption decreases. And on icebreakers, the stem is strongly inclined forward, due to which the ship crawls onto the ice and destroys it with its mass.

Body kit

The hull of any vessel must have strong connections in the vertical, longitudinal and transverse directions in order to withstand the pressure of the water, the shock of waves in any storm and other forces that act on it.

The underwater parts of the ship are experiencing the main load. Therefore, in the middle of the bottom set, the main longitudinal connection is established, which perceives the forces arising from the buckling of the vessel - the vertical keel. It runs the entire length of the hull, connects to the stem and sternpost, and its design depends on the type of vessel.

The bottom stringers run parallel to the keel along it, their number depends on the size of the ship and decreases towards the bow and stern, as the bottom width becomes smaller.

Often, to reduce the influence of the ship's side roll, side keels are installed, they do not go beyond the dimensions of the hull in width and have a different design.

Vertical steel sheets, called bottom floras, are installed across the hull and welded to the keel and can be both permeable and impermeable.

The set of boards continues the bottom set and consists of stringers (longitudinal beams) and frames (transverse stiffeners). The bow is considered in naval shipbuilding to be a zero frame, and the middle frame is considered midship.
The deck set is a system of intersecting longitudinal and transverse beams - beams.

Ship shell

The ship's shell consists of the outer bottom and side planking and deck flooring. The outer sheathing is made of horizontal individual belts, connected in various ways: close, butt, smooth, herringbone.

The underwater parts of the ship must be the strongest, therefore the lower (sheet pile) plating belt is made thicker than the intermediate belts. The planking belt, which is called the shirstrek, at the beams of the upper continuous deck, is of the same thickness.

Deck flooring consists of the longest sheets that rest on the deck set, and limits the top of the ship. The sheets are placed with the long side along the vessel. The smallest thickness of metal deck deck is 4 mm. can also be made of boards.

The deck is a set and deck.

Ship deck

In terms of height, the ship's hull is divided into several decks and platforms. A platform is a deck that does not run along the entire length of the ship, but only between several bulkheads.

Decks are named according to their location on the vessel, lower, middle and upper. At the ends of the ship (along the bow and stern) under the lower deck are platforms that are counted from top to bottom.

The number of both decks and platforms depends on the size of the vessel, its purpose and design.

River and mixed navigation vessels have one main or upper deck. Marine, such as a passenger ship, or rather a passenger ship, three decks.

Large lake passenger ships have an intermediate deck, in addition to the main one, which forms an interdeck space.

A cruise ship can have significantly more decks. For example, there were four of them on the Titanic, stretching along the entire length of the ship, two platforms that did not reach either the bow or the stern, one was interrupted in the bow, and one was located only in the front of the liner. The newest liner Royal Princess has nineteen decks .

The upper deck, also called the main or main deck, withstands the greatest stresses during transverse compression and buckling of the hull. The deck of the ship is usually made with a slight rise in the center to the bow and stern and a bulge in the transverse direction, so that water that has fallen on the deck when the sea is rough can easily flow down to the sides.

Ship superstructures

Deck superstructures are superstructures located across the entire beam of the vessel. They form closed volumes that are used as office and living quarters. Superstructures are called sidewalls, the side walls of which continue the side of the ship. But more often than not, the rooms above the upper deck do not reach the sides. Therefore, there is a somewhat conventional division into superstructures proper, which are located on a rather large length of the ship, and deckhouses, also superstructures, but short.

Since the upper deck of the ship is divided into sections that have their own names, the same names are given to the superstructures located on them: tank or bow, stern or poop and middle. The forecastle - bow superstructure - is designed to increase the bow of the hull.

The tank can take up to 2/3 of the length of the vessel. In an extended tank, cabins are located on passenger ships, and on cargo ships - cargo twin decks.
In the aft superstructure - a poop or poop - they don't arrange living quarters for the team.

Between superstructures, the deck is fenced with bulwarks, which should protect the deck from flooding with water.

On sea-going vessels, depending on the type and purpose of the vessel, felling is performed in several tiers.

On river vessels Only the rooms in which the steering wheel and radio are located are called wheelhouses, and all other structures on the upper deck are superstructures.

Ship compartments

The structure of a warship or a civilian ship implies the presence of watertight compartments that increase its unsinkability.

Internal vertical walls (bulkheads) are made watertight, dividing the length of the inner volume of the ship into compartments. They prevent water from filling the entire internal volume in case of damage in the underwater part of the ship and the spread of fire.

The compartments of the ship, depending on the purpose, have their own names. The main power plants are installed in a compartment called the engine or engine room. The engine room is separated from the boiler room by a watertight partition. Cargoes are transported in cargo compartments (holds). The living quarters for the crew and passengers are called living and passenger holds. Fuel is stored in the fuel compartment.

Rooms in the compartments are fenced with light bulkheads. To get into the compartments, rectangular hatches are made in the deck flooring. Their sizes depend on the purpose of the compartments.

Marine propulsion system

The propulsion system on a ship consists of engines and auxiliary mechanisms that not only set the ship in motion, but also provide it with electricity.

The ship is set in motion by the main mover, connected by a shaft line.

Auxiliary mechanisms provide the vessel with electricity, desalinated water, steam.

According to the principle of operation and type of the main engine, as well as energy sources, the ship's power plant can be steam or steam turbine, diesel, diesel turbine, gas turbine, nuclear or combined.

Marine devices and systems

The structure of the ship is not only the hull and superstructures, it is also ship devices, special equipment and deck mechanisms that ensure the operation of the ship. Even people far from shipbuilding cannot imagine a ship without a steering or anchor device. And also on each vessel there is a towing, mooring, boat, cargo device. All of them are powered and serviced by deck auxiliary mechanisms, which include steering gears, towing, cargo and boat winches, pumps and much more.

Ship systems are many kilometers of pipelines with pumps, instruments and apparatus, with the help of which water is pumped out from holds or drains, drinking water or foam is supplied in case of fire, heating, air conditioning and ventilation are provided.

The mechanisms of the engine room are served by a fuel system for powering engines, an air system for supplying compressed air, and cooling engines.

With the help of electrical equipment, lighting on the ship and the operation of mechanisms and devices that are powered by the ship's power plant are provided.

All modern ships are equipped with sophisticated navigation equipment for determining the direction of movement (course) and depths, measuring the speed of the course and detecting obstacles in fog or oncoming ships.

External and internal communication on the ship is carried out using radio equipment: radio stations, ultra-short-wave radio telephones, ship telephone exchanges.

Ship premises

The ship premises, no matter how many there are on the ship, are divided into several groups.

These are living quarters for the crew (officers 'cabins and sailors' quarters) and for passengers (cabins of various capacities).

A passenger liner is already a rarity today. Few people allow themselves to travel at low speed over long distances. Air travel can be made much faster. Therefore, passenger cabins are more of an accessory for cruise ships.

Passenger cabins, especially on cruise ships, are divided into several classes in terms of comfort. The simplest cabin resembles a railway carriage compartment with four shelves and almost no furniture, often facing inside the hull and without a porthole or window, with artificial lighting. The Royal Princess liner also provides passengers with luxurious two-room suites with balconies.

A cabin on a ship, namely on a military ship, is a resting room for crew officers. The ship commander and senior officers have separate single cabins.

Public spaces are salons, cinemas, restaurants, libraries. For example, the cruise ship Oasis of the seas on board has 20 restaurants, a real ice skating rink, a casino and a theater for 1380 spectators, night club, jazz club and disco.

The sanitary facilities include sanitary facilities (laundries, showers, bathrooms, baths) and household facilities, which include kitchens, all kinds of storerooms and utility rooms.

Passengers are usually denied access to office spaces. These are the premises in which the ship is controlled, or radio equipment, the engine room, workshops, storerooms for spare parts and other ship supplies are located.
Special-purpose premises include cargo holds, storage of solid or liquid fuels.

Sailing vessel

The structure of a sailing ship is not much different from a conventional ship. Only with sailing equipment, spars and rigging.

Sailing rig - a set of all the sails of the ship. Mast - the parts that directly carry the sails. These are masts, yards, topmills, bowsprites, geeks and other elements familiar from books about pirates of past centuries.

Special tackle, with the help of which masts, bowsprites and topmills are fixed in a certain position, are called standing rigging, for example, cables. Such equipment remains stationary and is made of thick resin, made from plant materials, or galvanized iron or steel cable, and in some places - chains.

Movable gear, with the help of which sails are set and removed, perform other operations related to the management of a sailing vessel, are called running rigging. These are sheets, halyards and other elements made of flexible steel, synthetic or hemp cables.

In all other respects, even in the number of decks, they are similar to their brothers.

The multi-deck sailing ship appeared in the 16th century. On Spanish galleons, depending on the displacement, there could be from 2 to 7 decks. The superstructure was also built in several tiers, which housed living quarters for crew officers and passengers.

The structure of a ship, at least its main structural elements, does not depend on the type and purpose of the ship, whether it be sailboats driven by the force of wind blowing sails, or paddle steamers with a steam engine as a propulsion device, cruise liners with a steam turbine installation, or nuclear icebreakers.

Looking at the ship in profile, you can evaluate its outline and hull lines. The vessel itself is a frame, called a set, and a skin. The body kit serves to stiffen the entire structure. It also forms the appearance of the ship, its contours. It can be seen that in its front (bow) part, the vessel has a special shape. The bow of the ship is specially made pointed so that when moving through the water column the ship experiences minimal resistance of the environment.

The forward end of the ship in naval terminology is called the bow. By its location, it is opposite to the stern. The bow of the ship most often has an elongated shape, narrowed from the sides. Its function is to cut the waves that impede the rapid movement of the vessel. Such a peculiar shape of the bow is best suited to the operating conditions of the ship.

Elements of the bow of the ship

The bow of the ship has a complex structure. It is designed in such a way as to minimize resistance to water elements. At the very end of the nose is the stem. This is a thick bar, which is a kind of continuation of the keel. In the place where the stem comes to the waterline, a metal plate is often placed, which is called "green" or "water cutter".

In ancient times, on the prow of sailing ships, ornaments were usually placed in the form of figures - rostra, which performed a decorative function. Such images not only made the ship more attractive, but often made warships look intimidating. Roman warships, instead of decorative figures, often had massive battering rams in front, with which the nose ended.

Deck elements at the fore of the vessel also have their own names. The bow space of the upper deck of the ship is called "tank". On a sailing vessel, the tank starts at the foremast and ends at the foremost end of the vessel. Sometimes the ship has an elevation on the deck in the front part - a forecastle. This structural element can occupy up to half of the entire length of the vessel. Rigging and mooring equipment is installed on the front of the deck.

In the area of \u200b\u200bthe bow, the ship's hull has a reinforced structure. The set is stronger and more frequent here, and the casing is of considerable thickness and strength. This is done so that the ship has the ability to confidently go against the wind and strong waves. A strong bow is also needed when touching the berth at the moment of mooring. In any swimming conditions, the nose takes on the main load of the external environment, so the requirements for its design are always more stringent.

When looking at an ocean-going ship, it is not always possible to imagine how many parts it consists of. At first, the external forms of the structure, the contours of the hull and deck superstructures are striking. Meanwhile, any ship is a complex system that includes a number of elements, each of which has its own purpose and name.

The main parts of the ship

The basis of any ship, be it a small craft or a giant ocean liner, is its hull. It consists of a set, which includes rigid longitudinal and transverse elements, as well as a skin that is attached to the set from the outside. The set, in combination with the hull, gives the boat a smooth outline, watertightness and protection of the hull from damage. This is a kind of backbone, the skeleton of a ship.

Conventionally, the body can be divided into two parts. The front is called the bow, and the rear is called the stern. The part of the ship that is below the waterline is called underwater. Everything that rises above the surface of the water is the surface of the ship. The stern and bow on either side of the centerline are connected by sides.

The horizontal surface at the top of the hull is called the deck. It has long been recruited from boards tightly fitted to each other. One or more vertical masts are installed on the decks of sailing ships, to which sails and rigging equipment are attached.

Large ships are equipped with a superstructure in their upper part. This structure serves as a continuation of the sides and can occupy a significant part of the deck area. The massive superstructure allows efficient use of the space on the deck, but worsens the stability of the ship and increases its windage. To control the ship, the wheelhouse, which is part of the superstructure, is intended.

Other structural elements of the ship

In the middle and bow of the ship, you can often see the continuation of the side, rising slightly above the surface of the deck. This lightweight construction made of wood or heavy canvas is called a bulwark. It can be stationary or temporary. Bulwarks are indispensable during rough seas, when passing dangerous reefs and sailing.

They have their own names and elements of the ship set. The main longitudinal part of the structure, which runs along the entire hull in its lower part, is called the keel. In front, the keel passes into an inclined stem. The stern end of the keel is called the sternpost. The steering wheel is usually hung on it. Shaft can also be passed through the sternpost

Have you noticed how easy it is for us to breathe at sea? The thing is that the sea air contains small particles of sea water, rich in minerals. By acting on the mucous membrane of the respiratory tract, they not only moisturize it, but also help the epithelial cells to work more efficiently.

Rinsing the nose with sea water has been practiced for a long time, but it was not immediately possible to scientifically prove its positive effect on health. It is still believed that a salt solution (or saline solution) is comparable in effectiveness with seawater-based sprays.

However, this is not true:
Exposure to minerals is only possible when using sea salt. In addition to sodium and chlorine, seawater contains magnesium and calcium ions, which stimulate the nasal mucosa. Particularly important are magnesium ions, which contribute to the production of energy necessary for the ciliated cells of the mucous membrane to remove pathological microorganisms from the nasal cavity 1;

Mechanical cleansing will help both in the prevention and treatment of the common cold. The effectiveness of the prevention and treatment of rhinitis with the help of regular nasal lavage has been repeatedly subjected to clinical studies both in Russia and abroad.
Nasal lavage helps with diseases such as colds (ARVI), rhinitis (runny nose), sinusitis (inflammation of the sinuses), allergic rhinitis, and respiratory diseases associated with air pollution in big cities and at work 1. Rinsing the nose with seawater, as part of complex therapy, will help to avoid the development of such unpleasant complications as, for example, otitis media, sinusitis, frontal sinusitis, as well as chronicity of process 1;

Liquefying mucus and making it easier to remove it from the nose also happens in different ways. Regular rinsing of the nose with sea water prevents the thickening of mucus in the nasal cavity and clears the mucous membrane of bacteria, viruses and allergens, improves the performance of the microcilia, which are responsible for the distribution of mucus in the nasal cavity and the removal of mucus, and with it bacteria, viruses, allergens from the nasopharynx.

To learn how to properly rinse your nose, watch our animated video on this topic.

Remember personal and nasal hygiene. In the latter, the Marimer seawater can help.

Marimer is natural seawater for the prevention and treatment of rhinitis. Thanks to the innovative spraying system, in one injection, many micro-drops of seawater are gently distributed throughout the nasal cavity and help to effectively clear mucus from it 2.

Each microparticle of Marimer seawater contains beneficial trace elements that help support the protective functions of the nose from the very beginning of the treatment of the common cold. The unique design of the can helps to avoid discomfort for a soft and comfortable use. A wide range of products will allow you to choose the right format for each family member 2.

Marimer seawater is collected every day, offshore at a depth of several meters in Atlantic waters in a bay near Saint-Malo. This bay has powerful ebb and flow, and the constant mixing of the water provides a rich variety of seaweed, which means a high content of mineral elements.

Sterility is ensured through a microfiltration process without irradiation and the use of antiseptics (no chemicals are used in water treatment). Within a few days after collection, water is poured into bottles. During the manufacturing process, water quality is monitored to ensure the highest level of safety. A special valve in the nozzle prevents bacteria and other contaminants from entering the bottle.

The innovative spraying system (microdiffuse) creates an optimal droplet / aerosol particle size, ensuring - accurate and continuous spraying, even and maximum complete distribution of the solution on the mucosal surface.

1 GS Maltseva, "The use of sea water for the prevention and treatment of diseases of the nasal cavity and nasopharynx in children." // Journal "Pediatrics", No. 03, 2013.
2 Instructions for the medical use of MARIMER FORTE and MARIMER preparations dated 05/07/2015 and 05/06/2015.

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Surface ships and submarines built for the Russian Navy during the late USSR can be criticized
forge for imbalance in the composition of weapons, inability to use it at full range, lack of
a combat information and control system like Aegis - for anything other than aesthetic imperfection.
Graceful predatory silhouettes of cruisers, BODs, destroyers, multipurpose nuclear submarines, inherited from the Soviet
shipbuilding school, continue to delight the eye and cause pride in Russian citizens and respect in half
with envy of the subjects of foreign states (destroyers, unfortunately, are only pleasing to the eye).

Judging by the projects of the ships of the last (fourth) generation, developed at the Severny Design Bureau and the Almaz Central Design Bureau (22350 and 20380),
ship architecture continues to receive due attention and, despite new requirements that run counter to aesthetics,
nK radar signature, frigates and corvettes under construction are as pleasing to the eye as their predecessors. But,
unfortunately, the reverent attitude towards the long-standing traditions and canons of the genre is not universal. To date
two alarm calls have already been received, causing concern for the new look of the Russian Navy.

1. The forward-inclined forward wall of the conning tower of the APCR (RPKSN) project 955 "Borey"

Fencing of the cabin APKR pr. 955 (slightly retouched photo from newsreaders.ru from skroznik, submitted by tsonyo from forums.airbase.ru)

They prefer not to mention this architectural absurdity in the descriptions of the Boreyev construction, but questions arise from
many and sometimes they are even asked to the authors of the project. Quote : "(correspondent of the Central Naval Portal Dmitry
Glukhov) - Why is the bow of the cabin (more precisely, the fencing of the retractable devices) of the SSBN of the Borey project is made so neo-
usually negative slope? (former general director of the Rubin Central Design Bureau Andrey Dyachkov) - This was done due to the peculiarities
placing in this place one of the stations of the sonar complex of the boat "(link).

That is, earlier, throughout the entire design and construction of nuclear submarines in Russia and abroad, there were no such features,
but, suddenly emerging, they turned out to be so significant for the combat effectiveness of a strategic submarine cruise
ra, that for this it was necessary to disfigure its silhouette (it is very difficult to imagine a car with a windshield
would be tilted outward or a dolphin with a forehead tilted forward). Doubts about the appropriateness of this constructive
solutions arise also because A. Dyachkov's commentary is, of course, not about the main, but about the auxiliary (second
power) station GAK, presumably - mine detection (opinionCurious c forums.airbase.ru).

The point here, most likely, is different. CDB "Rubin" has never attached much importance to the form of fencing the felling of its projects -
they were always either strictly rectangular (family 667, 877, 677), or almost (949 / 949A). Obviously tired of this one-
obrazia, the bureau's management decided to enter the history of shipbuilding since "new cabin concept "(a phrase from Acustic with
forums.airbase.ru). Unfortunately, the military reception, the fleet command and the state leadership did not have enough taste,
to interfere with the architectural research of "Rubin" and order it to be done as it should, that is, beautifully. Make it beautiful without
damage to the performance of individual products is always possible - there would be a desire (I know from experience).

For the sake of fairness, it should be noted that in some photographs where APCR are captured in foreshortening three-quarters from the nose or
stern, acquired ugliness is almost imperceptible, but the art of industrial design in particular consists in
his objects looked equally impressive from all sides.

2. The cut off bow end of the Mistral type DVKD

"Mistral" (photo from nemiga.info) -here THIS will show off in our parade line on the Day of the Navy!

Any reasonable explanation as to why the tip of the Mistral's nose ended up neatly cut off like a piece
sausages, I could not find. On the forums, the most incredible assumptions are put forward, such as a decrease in windage
(tiny nose and immense freeboard! ) or redirecting the incoming air flow in order to reduce
turbulence on the flight deck is a problem that for some reason stubbornly did not want and do not want to be noticed by the designers of all the others
aircraft carriers on the globe.

Or maybe everything is much simpler, and the clue to cutting the stem of the DVKD lies in the banal savings of the contractor company
on metal and man-hours? Or in the reluctance (inability) of the designer to find another way to meet the requirements set in the TTZ
load the masses and ensure normal alignment? After all, several tons of iron removed by a slight movement of the hand (thought) with
the very nose and the very top of the ship's hull are capable of having a much greater influence on the position of its center of gravity than
several hundred tons located amidships in the waterline area. Another option : longer flight deck was unnecessary,
and to make the body proportionally shorter (due to the cylindrical insert) was not possible (or simply did not want
moose to change the layout) - why engage in useless arts, if you can just brilliantly cut off the excess.

In general, the cropped Mistral fits well into the general picture of the degradation of European (if not world) aesthetics
naval architecture with its Daring and Horizons. God is with them, it is their choice, but why drag this decadence into
Russia? To be honest, until the very launch of the Vladivostok, I childishly hoped that as part of the finalization of the project for
the needs of the Russian Navy, the Russian "Mistral" will be welded a piece of the stem taken from it, so that it ("Mistral") does not become too discordant
with the current ship composition of the domestic fleet. It didn’t come true. As in the case of "Boreas" the customer did not notice or
pretended not to notice the pronounced ugliness and did not insist on making changes to the project (the French were very
need this order and they probably would try).

I would like to think that the unsightly "Boreas" and "Mistrals" are an annoying misunderstanding that will not happen again, and our military
ships were, are and will bethe most beautiful in the world .

Other photos of the new concept of the wheelhouse enclosure of the Rubin Central Design Bureau

Modern ships are made of materials whose density is many times higher than that of water. But they do not sink, because they are designed in such a way that inside they have many rooms filled with air.

When it comes to a ship, we use the terms " ship " or " vessel ". Meanwhile, these concepts do not mean the same thing. In the general case, the ship is considered to be any vehicle, which is used to transport passengers and goods by water. Different rules and codes interpret this concept differently. For example, the International Regulations for Preventing Collisions of Ships at Sea states that a ship is any means of transportation on water. Hence, the ship is a broader concept. And ships are considered to be large sea vessels and ships of any size, carrying a naval flag. Each ship has its own unique name, flies under the flag of the state in which it is officially registered.

How the ship works

1 - bow, 2 - bulb, 3 - anchor, 4 - side, 5 - stern, 6 - stern, 7 - chimney, 8 - wheelhouse, 9 - deck.

The ship's hull consists of several parts.

The front is called nose ... During movement, it cuts the waves and is therefore shaped so that the resistance of the water is minimal. The front end of the nose is called stem ... And the part of the nose protruding below the waterline is called bulb ... It changes the direction of water flow through the hull, thereby reducing drag, increasing ship speed and reducing fuel consumption.

The back of the ship is called stern. It is divided into surface and underwater parts. In the underwater part there are steering wheel and propeller screw ... On the surface there is an engine room and a cargo compartment.

The side part is called board . Bulwark - this is the part of the side located above the deck.

The inner space of the ship is vertically divided into rooms by horizontal overlap - deck. There can be several decks: upper deck, wheelhouse deck, superstructure deck, tank deck, first, second deck, etc. It all depends on the size and purpose of the ship. For example, lifeboats are placed on the boat deck. Passenger ships have special promenade decks.

Along the bottom of the vessel, from bow to stern, there is a longitudinal beam, which is called keel ... It provides strength to the hull and bottom.

The line of contact of the hull with a calm water surface is called waterline ... It conventionally separates the surface and underwater parts of the ship.

In order to stay in one place, the ship in the parking lot must be thrown onto the ground anchor .

Marine engine sets in motion ship propellers : air and propeller, paddle wheel). Sailing ships are driven by sails. (Propellers are devices that convert engine energy or any other energy, such as wind energy, into work to move a vehicle).

The watertightness of the vessel, buoyancy and unsinkability provides body ... It consists of a casing and a kit.

Center of mass and center of pressure of the ship

When a ship is floating, two forces act on it, equal in magnitude and opposite in direction: gravity (weight) R and buoyancy.

Ship weight R Is the sum of the weights of the hull, mechanisms, fuel, water supplies, crew, weapons, etc. The force of gravity is always directed downward and pulls the ship to the bottom. It is attached to a point called the center of gravity of the ship, or center of gravity ... When designing and building a ship, they try to make sure that its center of gravity is in diametrical plane ... This is a vertical plane that runs through the entire length of the ship and divides it into 2 symmetrical parts. The center of gravity is located either at half the height of the freeboard or slightly below it.

The buoyancy force is applied to the geometric center of gravity of the submerged volume of the ship and is directed vertically upward. The point of application of the buoyant force is called pressure point , or center of pressure .

When creating a ship, make sure that both these centers (the center of gravity of the ship and the center of pressure) are in the center plane on the same vertical.

Equilibrium equation for the ship has the form:

P \u003d γ (V o - V n) , or:

P \u003d γ V

where

V n - the waterproof volume of the ship is above the waterline,

V o - the entire waterproof volume,

P - weight of the vessel,

γ - density of water,

V - immersed volume

This equation is called basic buoyancy equation.

Buoyancy

Buoyancy is the most important seaworthiness of a ship. It is the ability to stay afloat along with the cargo needed to complete certain tasks. Having lost its buoyancy, the ship will sink.

Each ship has buoyancy reserve , which is defined as the percentage of all watertight volumes of a ship located above the waterline to its total watertight volume.

W = V n / V o * 100

From the point of view of physics buoyancy apas is equal to the volume of water that the ship can take on board while staying afloat.

For example, if the buoyancy margin is 50%, then the vessel is immersed in water so that its waterproof volume above the waterline is equal to the volume below it.

The volume of superstructures and all protruding parts on the upper watertight deck is not included in the buoyancy reserve. The volumes of damaged compartments are also excluded from it.

If the ship takes on board an amount of water equal to the buoyancy reserve, then it will submerge in the water along the main deck. Its buoyancy reserve in this case will be zero. And the ship itself will be in an unstable position. In physics, this is called neutral buoyancy. Even a small impact on the ship in this state can lead to the fact that the buoyancy becomes negative and the ship sinks. Therefore hin order for the navigation to be safe, a mandatory buoyancy reserve ... It is designated cargo waterline or freight line - a special mark applied to the vessel. It shows the level to which the vessel can be loaded. The larger the load, the closer the load line is to the water.

To preserve the buoyancy reserve, the ship's hull and all its rooms are made waterproof. They are separated by bulkheads and decks. Doors, portholes, hatches are watertight. If water enters some room on the ship, it will not be able to enter other rooms. It is very important that all these ship structures are always in good condition.