Traveling along rivers and seas on ships has been known in history for more than five thousand years. Today, according to generally accepted terminology, a sea vessel is a cargo, passenger or commercial large-sized watercraft, and a ship is a military one. The list of ships could take a long time. The most famous maritime ones are sailing ships and yachts, passenger liners and steamships, boats, tankers and dry cargo ships. Ships are aircraft carriers, battleships, cruisers, destroyers and submarines.

Ship structure

Whatever type or class the watercraft belongs to, it has common design elements. First of all, of course, the hull, on which superstructures for various purposes, masts and deckhouses are installed. An important element of all ships are engines and propulsors, in general, power plants. Devices, systems, electrical equipment, pipelines and premises equipment are important for the life of a watercraft.

They are also equipped with spar and rigging.

The bow is the front end, the stern is the rear end of the hull, and its side surfaces are the sides. 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 the horizontal floors. The hold of a ship is the lowest room, which is located between the bottom and the lower deck. The space between decks is called a tween deck.

Ship hull design

If we talk about a ship in general, be it a warship or a civilian vessel, then its hull is a waterproof, streamlined body, hollow inside. 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 frame and plating. Bulkheads and decks are elements inherent to certain types of ships.

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

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

At the ends of the hull most often ends with strong beams: at the stern - with a sternpost, and at the bow - with a stem. Depending on the type of vessel, the contours of the bow may be different. Reducing resistance to the movement of the vessel, ensuring maneuverability and seaworthiness depend on them.

The underwater bow of the ship reduces water resistance, which means 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.

Case set

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

The underwater parts of the ship experience the main load. Therefore, in the middle of the bottom frame, the main longitudinal connection is installed, which absorbs the forces arising from the longitudinal bending of the vessel - the vertical keel. It runs the length of the hull, connecting to the stem and sternpost, and its design depends on the type of vessel.

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 width of the bottom becomes smaller.

Often, to reduce the influence of the ship's sideways motion, side keels are installed; they do not exceed the width of the hull and have a different design.

Vertical steel plates, called bottom floors, are installed across the hull and welded to the keel and can be permeable or impermeable.

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

Ship shell

The shell of the vessel consists of outer bottom and side plating and deck plating. The outer cladding is made of horizontal separate belts connected in various ways: overlapping, end-to-end, smooth, herringbone.

The underwater parts of the ship must be the strongest, therefore the lower (tongue) plating belt is made thicker than the intermediate belts. The thickness of the plating belt, called shearstrak, on the beams of the upper continuous deck is also the same in thickness.

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

A deck is a combination of decking and decking.

Ship deck

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

Decks are named according to their location on the ship: lower, middle and upper. At the ends of the ship (bow and stern), platforms run below the lower deck and 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 vessels and mixed navigation vessels have one main or upper deck. Marine ones, 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, forming an interdeck space.

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

The upper deck, also called the main or main deck, withstands the greatest stresses during transverse compression and longitudinal bending of the hull. The deck of a ship is usually made with a slight rise in the center towards the bow and stern and a convexity in the transverse direction, so that water that falls on the deck during rough seas flows more easily to the sides.

Ship superstructures

Deck superstructures are above-deck structures located across the entire width of the vessel. They form closed volumes that are used as office and residential premises. Side walls are called superstructures, the side walls of which continue the side of the ship. But most often the rooms above the upper deck do not reach the sides. Therefore, there is a somewhat conventional division into the superstructures themselves, which are located over a fairly large length of the vessel, 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: forecastle or bow, stern or poop and middle. The forecastle - the bow superstructure - is designed to increase the bow of the hull.

The tank can occupy up to 2/3 of the length of the vessel. The elongated forecastle is used for cabins on passenger ships, and cargo tween-decks on cargo ships.
In the aft superstructure - poop or poop - living quarters for the crew are arranged.

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

On sea vessels, depending on the type and purpose of the vessel, cuttings are carried out in several tiers.

On river ships, only the rooms containing the helm and radio are called deckhouses, and all other structures on the upper deck are called superstructures.

Ship compartments

The structure of a military or civilian ship implies the presence of watertight compartments, which increase its unsinkability.

The internal vertical walls (bulkheads) are made waterproof, dividing the internal volume of the ship into compartments along the length. They prevent water from filling the entire internal volume in the event of damage in the underwater part of the ship and the spread of fire.

The compartments of the ship, depending on their 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 waterproof partition. Cargo is transported in cargo compartments (holds). The living quarters for the crew and passengers are called accommodation and passenger holds. Fuel is stored in the fuel compartment.

The rooms in the compartments are protected by light bulkheads. To allow access to the compartments, rectangular hatches are made in the deck flooring. Their sizes depend on the purpose of the compartments.

Marine propulsion system

The power plant on a ship is the engines and auxiliary mechanisms that not only set the ship in motion, but also provide it with electricity.

The ship is driven by a main propulsion unit connected by a shafting.

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

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

Ship devices and systems

The structure of a ship is not only the hull and superstructures, it also includes ship equipment, 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. Each ship also has towing, mooring, boat, and cargo equipment. All of them are driven 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 of holds or wastewater, drinking water or foam is supplied in case of fire, and heating, air conditioning and ventilation are provided.

The engine room mechanisms are served by a fuel system to power the engines, an air system to supply compressed air, and cool the engines.

Electrical equipment provides lighting on the ship and the operation of mechanisms and devices that are powered by the ship's power plant.

All modern ships are equipped with sophisticated navigation equipment to determine direction of movement (course) and depths, measure speed and detect obstacles in fog or oncoming ships.

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

Ship premises

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 airliner is already a rarity today. Few people allow themselves to move at low speed over long distances. You can travel by air much faster. Therefore, passenger cabins are more of a property of cruise ships.

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

A cabin on a ship, specifically on a military ship, is a rest room for the crew officers. The ship's commander and senior officers have separate single cabins.

Public premises are salons, cinema halls, restaurants, libraries. For example, the Oasis of the Seas cruise ship has 20 restaurants on board, a real ice skating rink, a casino and a theater for 1,380 spectators, a nightclub, a jazz club and a discotheque.

Sanitary and utility premises include sanitary and hygienic (laundries, showers, bathrooms, baths) and household premises, which include kitchens, all kinds of storage rooms and utility rooms.

Passengers are usually prohibited from entering service areas. These are the rooms in which the ship is controlled, or where radio equipment, engine rooms, workshops, storerooms for spare parts and other ship supplies are located.
Special purpose premises include cargo holds, solid or liquid fuel storage facilities.

Sailing vessel

The structure of a sailing ship is not much different from an ordinary vessel. Only sailing equipment, spar and rigging.

Sailing rig - a set of all the sails of a ship. Spar - parts that directly support the sails. These are masts, yards, topmasts, bowsprits, booms and other elements familiar from books about pirates of past centuries.

Special gear, with the help of which masts, bowsprits and topmasts are secured in a certain position, is called standing rigging, for example, shrouds. Such equipment remains stationary and is made of thick resinous, plant-based, or galvanized iron or steel cable, and in some places, chains.

Movable gear, with the help of which the sails are set and removed, and perform other operations related to the control 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 counterparts.

A multi-deck ship under sail appeared in the 16th century. Depending on the displacement, Spanish galleons could have from 2 to 7 decks. The superstructure was also built in several tiers, which contained 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 vessel, be it sailing ships driven by the force of the wind, inflating sails, or paddle steamers with a steam engine as propulsion, cruise liners with a steam turbine unit, or nuclear icebreakers.

The outer lightweight hull of the submarine had the shape of a cylinder, gradually tapering towards the bow and stern. The main deck of the superstructure extended from the bow to frame 124 at the stern. In the bow it rose above the water level by 3.7 m, and in the stern by 1.2 m. The internal cavity between the superstructure and the strong hull was filled with water through scuppers during the dive.

The conning tower, located in the midship frame area, was covered from above by a bridge fence. The deck located immediately behind the wheelhouse was called the “cigarette deck” because sailors were allowed to smoke on it. A Browning anti-aircraft machine gun of 7.62 or 12.7 mm caliber was also installed here.

When submerged, the machine gun was retracted inside the boat. In 1941, machine guns were replaced by 20-mm Oerlikon Mark 4 Mod anti-aircraft guns. 3 with a rate of fire of 450 rounds/min, and in 1944 the Gato began to be equipped with 40 mm Bofors cannons with a rate of fire of 160 rounds/min.

The deck in front of and behind the bridge had a reinforced structure for installing guns. The artillery armament of the Gato boats was very diverse. The type and location of the guns depended on the time the boat was commissioned and the wishes of its commander.

At first, two deck-mounted 76.2 mm guns were installed on the submarines, but they turned out to be very weak weapons and could not cause serious damage even to small ships. During the operation of the boats, these guns were replaced with more powerful 102 mm or 127 mm Mk40 guns.

Their projectiles had several times greater mass and initial flight speed. In addition, the barrels of the 127-mm guns were made of stainless steel, which made it possible not to close the barrel with a plug when diving, and this speeded up bringing the weapon into firing position after surfacing.

At the bottom of the wheelhouse enclosure there were lockers for ammunition.

There were many visual differences between submarines produced by different shipyards. Most noticeable were the number, location and configuration of the scuppers. Some submarines were equipped with additional weapons and equipment.

And it is not without reason that naval historians claim that it is impossible to find two absolutely identical boats of the Gato type.

Hydroacoustic equipment

The first series of boats were equipped with WCA type sonars with a JT hydrophone. The hydrophone operated in the range 110 Hz - 15 kHz. The sonar range was 3429 m. It made it possible to determine the bearing and range to the target, and if the target was a submarine, then the diving depth was also determined. In 1945, the more advanced WFA sonar was adopted.

Of interest is the analysis of submarine operations carried out by the Bureau of Research during and after the war. This institution, organized in Washington and located in Pearl Harbor, analyzed 4,873 submarine attacks. It turned out that only 31 of them were produced using sonar devices. Moreover, of these attacks, only seven ended in the sinking of enemy ships.

To determine the temperature of the sea water, a barothermo-graph was used - SVT40131. In addition, a Benedix hydrodynamic log was installed on the submarines.

Handbook of Maritime Practices Author unknown

1.3. Submarine structure

Submarines are a special class of warships that, in addition to all the qualities of warships, have the ability to swim underwater, maneuvering along the course and depth. According to their design (Fig. 1.20), submarines are:

– single-hulled, having one strong body, which ends at the bow and stern with well-streamlined ends of a lightweight design;

- half-hulled, having, in addition to a durable body, also a lightweight one, but not along the entire contour of the durable body;

- double-hulled, having two hulls - strong and lightweight, the latter completely encircling the perimeter of the strong one and extending the entire length of the boat. Currently, most submarines are double-hulled.

Rice. 1.20. Design types of submarines:

a – single-hull; b – one and a half hull; c – double-hulled; 1 – durable body; 2 – conning tower; 3 – superstructure; 4 – keel; 5 – light body

A durable hull is the main structural element of a submarine, ensuring its safe stay at maximum depth. It forms a closed volume, impenetrable to water. The space inside the pressure hull (Fig. 1.21) is divided by transverse waterproof bulkheads into compartments, which are named depending on the nature of the weapons and equipment located in them.

Rice. 1.21. longitudinal section of a diesel battery submarine:

1 – durable body; 2 – bow torpedo tubes; 3 – light body; bow torpedo compartment; 5 – torpedo loading hatch; 6 – superstructure; 7 – durable conning tower; 8 – cutting fence; 9 – retractable devices; 10 – entrance hatch; 11 – stern torpedo tubes; 12 – aft end; 13 – rudder blade; 14 – aft trim tank; 15 – end (aft) watertight bulkhead; 16 – aft torpedo compartment; 17 – internal waterproof bulkhead; 18 – compartment of the main propulsion electric motors and power station; 19 – ballast tank; 20 – engine compartment; 21 – fuel tank; 22, 26 – aft and bow groups of batteries; 23, 27 – team living quarters; 24 – central post; 25 – hold of the central post; 28 – nasal trim tank; 29 – end (bow) watertight bulkhead; 30 – nasal extremity; 31 – buoyancy tank.

Inside the durable hull are quarters for personnel, main and auxiliary mechanisms, weapons, various systems and devices, bow and stern groups of batteries, various supplies, etc. On modern submarines, the weight of the durable hull in the total weight of the ship is 16-25 %; in the weight of hull structures only – 50-65%.

The structurally sound hull consists of frames and plating. The frames, as a rule, have an annular shape and an elliptical shape at the ends and are made of profile steel. They are installed one from the other at a distance of 300-700 mm, depending on the design of the boat, both on the inside and outside of the hull skin, and sometimes in combination on both sides closely.

The shell of the durable hull is made from special rolled sheet steel and welded to the frames. The thickness of the skin sheets reaches up to 35 mm, depending on the diameter of the pressure hull and the maximum immersion depth of the submarine.

Bulkheads and pressure hulls are strong and light. Strong bulkheads divide the internal volume of modern submarines into 6-10 waterproof compartments and ensure the ship's underwater unsinkability. According to their location, they are internal and terminal; in shape - flat and spherical.

Light bulkheads are designed to ensure the ship's surface unsinkability. Structurally, bulkheads are made of frames and sheathing. A bulkhead set usually consists of several vertical and transverse posts (beams). The casing is made of sheet steel.

End watertight bulkheads are usually of equal strength to the strong hull and close it in the bow and stern parts. These bulkheads serve as rigid supports for torpedo tubes on most submarines.

The compartments communicate through watertight doors having a round or rectangular shape. These doors are equipped with quick-release locking devices.

In the vertical direction, the compartments are divided by platforms into upper and lower parts, and sometimes the boat’s rooms have a multi-tier arrangement, which increases the useful area of ​​the platforms per unit volume. The distance between the platforms “in the light” is made more than 2 m, i.e., slightly greater than the average height of a person.

In the upper part of the durable hull there is a strong (combat) deckhouse, which communicates through the deckhouse hatch with the central post, under which the hold is located. On most modern submarines, a strong deckhouse is made in the form of a round cylinder of small height. On the outside, the strong cabin and the devices located behind it, to improve flow around when moving in a submerged position, are covered with lightweight structures called the cabin fencing. The deckhouse casing is made of sheet steel of the same grade as the robust hull. The torpedo-loading and access hatches are also located at the top of the durable hull.

Tank tanks are designed for diving, surfacing, trimming a boat, as well as for storing liquid cargo. Depending on the purpose, there are tanks: main ballast, auxiliary ballast, ship stores and special ones. Structurally, they are either durable, that is, designed for maximum immersion depth, or lightweight, capable of withstanding pressure of 1-3 kg/cm2. They are located inside the strong body, between the strong and light body and at the extremities.

Keel - a welded or riveted beam of box-shaped, trapezoidal, T-shaped, and sometimes semi-cylindrical section, welded to the bottom of the boat hull. It is designed to enhance longitudinal strength, protect the hull from damage when placed on rocky ground and placed on a dock cage.

Lightweight hull (Fig. 1.22) is a rigid frame consisting of frames, stringers, transverse impenetrable bulkheads and plating. It gives the submarine a well-streamlined shape. The light hull consists of an outer hull, bow and stern ends, deck superstructure, and wheelhouse fencing. The shape of the light hull is completely determined by the outer contours of the ship.

Rice. 1.22. Cross section of a one-and-a-half-hull submarine:

1 – navigation bridge; 2 – conning tower; 3 – superstructure; 4 – stringer; 5 – surge tank; 6 – reinforcing stand; 7, 9 – booklets; 8- platform; 10 – box-shaped keel; 11 – foundation of the main diesel engines; 12 – casing of a durable hull; 13 – strong hull frames; 14 – main ballast tank; 15 – diagonal racks; 16 – tank cover; 17 – light hull lining; 18 – light hull frame; 19 – upper deck

The outer hull is the waterproof part of the lightweight hull located along the pressure hull. It encloses the pressure hull along the perimeter of the boat's cross-section from the keel to the top watertight stringer and extends the length of the ship from the fore to aft end bulkheads of the pressure hull. The ice belt of the light hull is located in the cruising waterline area and extends from the bow to the midsection; The width of the belt is about 1 g, the thickness of the sheets is 8 mm.

The ends of the light hull serve to streamline the contours of the bow and stern of the submarine and extend from the end bulkheads of the pressure hull to the stem and sternpost, respectively.

The bow end houses: bow torpedo tubes, main ballast and buoyancy tanks, a chain box, an anchor device, hydroacoustic receivers and emitters. Structurally, it consists of cladding and a complex set system. Made from sheet steel of the same quality as the outer casing.

The stem is a forged or welded beam that provides rigidity to the bow edge of the boat hull.

At the aft end (Fig. 1.23) there are located: aft torpedo tubes, main ballast tanks, horizontal and vertical rudders, stabilizers, propeller shafts with mortars.

Rice. 1.23. Diagram of stern protruding devices:

1 – vertical stabilizer; 2 – vertical steering wheel; 3 – propeller; 4 – horizontal steering wheel; 5 – horizontal stabilizer

Sternpost – a beam of complex cross-section, usually welded; provides rigidity to the aft edge of the submarine hull.

Horizontal and vertical stabilizers provide stability to the submarine when moving. Propeller shafts pass through horizontal stabilizers (with a two-shaft power plant), at the ends of which propellers are installed. Aft horizontal rudders are installed behind the propellers in the same plane with the stabilizers.

Structurally, the aft end consists of a frame and plating. The set is made of stringers, frames and simple frames, platforms and bulkheads. The casing is of equal strength to the outer casing.

The superstructure (Fig. 1.24) is located above the upper waterproof stringer of the outer hull and extends along the entire length of the pressure hull, passing beyond its limits at the tip. Structurally, the superstructure consists of sheathing and frame. The superstructure contains various systems, devices, bow horizontal rudders, etc.

Rice. 1.24. Submarine superstructure:

1 – booklets; 2 – holes in the deck; 3 – superstructure deck; 4 – side of the superstructure; 5 – scuppers; 6- pillers; 7 – tank cover; 8 – casing of a durable hull; 9 – strong hull frame; 10 – light hull lining; 11 – waterproof stringer of the outer casing; 12 – light hull frame; 13 – superstructure frame

Retractable devices (Fig. 1.25). A modern submarine has a large number of different devices and systems that ensure control of its maneuvers, use of weapons, survivability, normal operation of the power plant and other technical means in various sailing conditions.

Rice. 1.25. Retractable devices and systems of a submarine:

1 – periscope; 2 – radio antennas (retractable); 3 – radar antennas; 4 – air shaft for diesel operation under water (RDP); 5 – RDP exhaust device; 6 – radio antenna (collapsing)

Such devices and systems, in particular, include: radio antennas (retractable and retractable), exhaust device for diesel operation under water (RDP), RDP air shaft, radar antennas, periscopes, etc.