Instruction

Every ship has a hull. It determines the appearance and contours of the vessel. In the hull, the rear part is distinguished - the stern, the bow, one or even several decks and the hold. Deck superstructures are located at the ends of the ship. In front it is a tank, and behind it is a poop, which is often covered with a dense awning on sailing ships. Vessels built according to the catamaran scheme have two separate hulls connected to each other in a rigid way or by means of hinged structures.

The boat must be between the wind and the man in the sea. Thus a ship that has a stronger catch in the wind than a man to recover it will drift towards it and it can be quickly approached. The current does not work. The engine must not be restarted until the person has been recovered.

Take a buoy or a corpse

The acceptance of a dead body or buoy is always met with wind. Thus, there is no risk of damaging the propeller by hitting the chain connecting the buoy or dead body to the ground. It is necessary to arrive at a reduced speed, then break the wreck of the ship near the buoy and quickly grab the buoy to dock the boat.

The internal space of the hull is divided by bulkheads into several longitudinal and transverse parts. To make the ship unsinkable, the compartments are most often made airtight and independent of each other. If the ship gets a hole, then water will accumulate in only one of the compartments, the rest will provide the ship with buoyancy. Powerful pumps are provided for pumping out water in each compartment of a modern ship.

Docking must be done at a reduced speed to limit the risk of sudden pontoon strike. It is necessary to introduce yourself slowly at an angle of 30 or 40 ° relative to the pontoon. Therefore, in order to bring the ship's stern closer to the pontoon, the bar should be located on the side of the quay. Get out of line quickly to avoid boat support and place the bar straight. Quickly move the moorings to the ground and keep the ship against the pontoon.

In the case of docking, you must be careful with the underwater zone. Therefore, it is necessary to arrive at an angle and aim at the third visible docking ring. The vessel in which Teseo set out on other young warriors and brought it triumphantly to Athens was a thirty-hour oar, which the Athenians held until the time of Demeter Phalera. They took away the old pieces when they deteriorated and replaced them with new pieces that bonded tightly to the old structure until there was not even a nail or beam from the original ship.

A ship in the water is conditionally divided into two parts - surface and underwater. The line along which the surface of the water touches the hull is called the waterline. Usually, a load waterline is applied to the skin. It indicates the maximum draft that is permissible when the vessel is fully loaded. From the outside, on the underwater part of the ship, there is a propeller and a rudder. Inside the underwater part, the engine room and cargo rooms are most often arranged.

Even philosophers, discussing their sophistication, cite this ship as an example of doubt, and one states that it is always the same ship, and others a different ship. However, as is often the case, things are not so simple. Thomas Hobbes, for example, goes further and asks us to imagine a situation where someone retained the old wooden planks of the original ship and subsequently reassembled them in the same order in which they were previously removed. Assuming that each of the boards that made up A had not deteriorated to the point where it could no longer be reused, it seems plausible to believe that the newly assembled ship is in fact the ship with which Teseo triumphantly triumphed in Athens.

The bow of the ship provides an easy move when moving at high speeds. The elongated and pointed bow of the vessel allows you to cut through the water column without any extra effort. The nose on both sides of the hull goes into the side. That part of it, which is installed above the deck, is called the bulwark. In the rear of the hull, both sides end in the stern.

Suppose that, shortly before returning to Athens, Teio solemnly promised that if ever a ship was sunk, she would go with her. Be that as it may, the question now is: what to do if two ships collide with the Greek coast and, by chance, see them fall together?

The only thing left to do at this point is to try and make some clarity. Rather, consider that the only way to adequately account for the problem is to accept the argument that what makes an object identical to another is the absolute material identity of the object in question. After all, it is plausible to think that an artifact can be taken apart and then reassembled, even though it is still numerically identical to the "starting artifact". And that's the last thing that really matters.

The upper part of the ship's hull is called the deck. Various deck structures are installed on it; on sailing ships, masts and related equipment for sail control are placed here. The number of masts on large sailing ships of past centuries reached three or even five. Rigging systems are used to securely hold the masts in a vertical position, set and stow the sails.

How exactly? As is often the case, such paradoxes arise from questions that are rather trivial, such as: how can one change and, in spite of everything, retain its identity? The answers, as we have just seen, are almost simple. Moreover, note that the question of identity concerns not only artifacts such as ships, statues, auditoriums, or entire cities, but also, and above all, people, that is, people in flesh and bone. In fact, since we are also If, as Heraclitus teaches us, "do all things flow", can we bathe twice in the same river?

A horizontally located deck, as a rule, consists of a base (set) and an upper deck. If the ship has several decks, then they usually have their own purpose. Particularly large vessels can have strong double decks and the same massive double bottom. This design allows you to protect the ship from overloading during heavy seas.

And again, if people are constantly changing, is it just the right to punish someone for committing a crime, years ago, when supposedly there was this "other person"? It is clear that here the clash between competing theories may have been especially severe: in fact, it must be about questioning our understanding of inanimate objects, and that our understanding still needs to be questioned when it comes to what to do with our personal identity and our persistence over time.

What is the moral we can draw from all these considerations? One of the first remarks to be made is that paradoxes may not reside only in the minds of cunning philosophers, logicians, or mathematicians, but perhaps they may have much more real consequences than they might believe. The other is that without paradoxical philosophical reflection it would probably lose much of its charm, which clearly does not mean that it would be impossible to philosophize, but only that it would be less interesting to deal with it, after all, if paradoxes there would be merit, our ability to reason, providing those limiting cases by which the plausibility of our intuition can be measured.

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, which includes a number of elements, each of which has its own purpose and name.

A guide to the discovery of the Janas ship and Bitia Tirrenia's twin. Continue with a new exit to help you discover the ships of the companies we represent. We boarded the Janas ship from Tirrenia and visited, photographed and filmed to show you all the beauty of these two ships.

Yanas in the port of Civitavecchia. The ships are in service on the route to Sardinia from or. Solutions for sleeping on board. Chair; cabins with 2, 3 or 4 beds inside and outside; cabin with access to animals; disabled cabin 3 internal or external beds; bed. All cabin cabins have bathrooms with showers and are divided between inside and outside. All types of cabins and their bathrooms are equipped with bath sheets.

The main parts of the ship

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



Cabins for the disabled are equipped with either external or internal with 3 single beds and consist of a single bed and a bunk bed. The bathroom is also large and equipped for the disabled. The entire ship allows the mobilization of wheelchairs from the garage, with an elevator and parking spaces for people with reduced mobility located next to the elevator. The garage has a special signalization for car parks and how to get to it.

Conventionally, the body can be divided into two parts. The front is called the bow, and the back 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 - surface part ship. The stern and bow on both sides of the center line 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. On the decks of sailing ships, one or more vertical masts are installed, to which sails and rigging equipment are attached.





Pet cabins benefit from precise daily sanitation to ensure maximum hygiene.

Those who wish to travel in a chair will be able to leave their four-legged friends at the kennel. Cabins with access to animals have a cost plus euros.

We remind you that you cannot leave animals in the car during the viewing.

Large ships in their upper part are equipped with a superstructure. This design serves as a continuation of the sides and can occupy a significant part of the deck area. A massive superstructure makes it possible to efficiently use the space on the deck, but worsens the stability of the ship and increases its windage. The cabin, which is part of the superstructure, is intended to control the ship.



All outside cabins have portholes and a bathroom with shower, two bunk beds and two high beds in a 4 bed configuration and 2 low beds and 1 high bed in a 3 bed configuration. There is no TV in the cabins. Only 1 or 2 people can be occupied as they pay for cabin exclusivity. When multiple people are near the beds, this is defined as the exclusive use of the cabin, as other people are not allowed to use the access.

Other ship design elements

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



Inside cabin with 4 beds Inside cabins are identical appearance, but do not have a porthole, instead you will find a beautiful painting or design. They also have a bathroom with a shower and 2 beds and 2 beds. Cabins are not equipped with TVs. As with the outside stands, only one person can be occupied, with 2 or 3 people always enjoying exclusive use.

Cabins with 2 beds are identical to 4 beds as a place.

Interior and bathroom are different from 4 beds as they only have two lower beds. Cabins with 2 beds in some periods are obtained from quad cabins by closing the two upper beds.

They have their own names and elements of the vessel 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 aft end of the keel is called the sternpost. A steering wheel is usually hung on it. The propeller shaft can also be passed through the stern. This part of the structure should be the most durable, because the load on it during movement is very high.

A bed can be booked in a 4-bed cabin where people are divided by gender. You cannot choose between low or high bed.

There are two 2nd class seats on board the ship for which they cannot be reclined. The chairs are also equipped with luggage racks for those who travel in a chair and without a car.

Bridge Deck The bridge deck is easy access to the ship, you won't have any type of chair so you should look for alternative seating options. The restaurant is especially bright thanks to its windows with external glass.

There are tables with easy access for the disabled and high chairs for children.

Parallel to the keel on the sides and bottom of the vessel are stringers that provide internal longitudinal connections. They are connected to the transverse elements of the set - frames. These parts of the structure, together with stringers, give the body external contours and smooth outlines. The skin is attached to such longitudinal and transverse bonds.

Related article

Warship- a complex self-propelled engineering structure, bearing the naval flag of its state assigned to it and staffed by a military team. It is equipped with modern equipment, mechanisms and weapons and is designed to perform tasks typical of its class. Any ship must have certain seaworthiness, survivability and have a minimum weight (displacement) with sufficient strength and the required weapons. The basis of any ship is the hull.

Surface ship hull(Fig. 1.1) - a steel waterproof hollow body with a streamlined shape. It provides the creation of buoyancy force and is a platform on which various weapons and equipment are mounted, due to the purpose of the ship. The hull is equipped with steering, anchor, mooring, towing, lifting and other devices. Inside the hull are located: the main and auxiliary mechanisms, residential and service premises, ammunition cellars, storage of fuel, oils, water, chain boxes for cleaning anchor chains and other internal devices. Superstructures are installed on the upper deck of the hull, masts, pipes and other structures and mechanisms are removed.

Rice. 1.1. The location of the main structures of the hull, the placement of weapons, posts and premises on a surface ship:
A - tank; B - waist; B - yut; 1 - guisstock; 2 - upper deck; 3 - bow anchor device; 4 - breakwater; 5 - bow artillery installation; 6 - anti-submarine weapons; 7 - bow (navigation) bridge; 5 - artillery fire control post; 9 - mast; 10 - chimney; 11 - torpedo tube; 12 - stern bridge; 13 - aft artillery mount; 14 - aft spire; 15 - flagpole; 16 - valance; 17 - platform; 18 - personnel quarters (stern); 19-stern ammunition cellar; 20-compartment of auxiliary mechanisms; 21 - engine room; 22 - watertight bulkheads; 23 - boiler room; 24 - second bottom; 25 - living quarters for officers; 26 - crew quarters (nasal); 27 - bow ammunition cellars; 28 - spire compartment; 29 - chain box


Structurally, the hull of a surface ship consists of the following main parts: a set (skeleton), side and bottom plating, decks and platforms, an inner bottom, longitudinal and transverse watertight bulkheads. Set and plating are essential elements of any hull; the presence of decks and bulkheads depends on the purpose of the ship.


Rice. 1.2. Ship Hull Recruitment System:
1 - beams of the main direction; 2 - cross beams


Housing set- a system of rigidly interconnected longitudinal and transverse beams of various designs, connected by welding or riveting to the sheets of the outer plating, second bottom and decks. In most cases, the resulting floors are reinforced by a set of whole (continuous) beams, called main direction beams, and split beams perpendicular to them, called cross beams (Fig. 1.2).

Depending on the direction of the main beams relative to the ship, there are three framing systems: transverse, longitudinal and mixed. In the transverse framing system of the hull, the beams of the main direction run across the ship, are structurally continuous along its width and consist of frames along the sides, transverse beams along the decks and floors along the bottom. With a transverse framing system, longitudinal beams (vertical keel, stringers) are also required, but the latter are cross-braces, their number is small (3-5). This dialing system is widely used on river and small sea vessels (tugboats, barges).

In the longitudinal framing system, the main (continuous) beams run along the ship and consist of a significant number of stringers running continuously along the bottom and sides, longitudinal beams along the decks and a large number of simple longitudinal beams located along the bottom, second bottom, sides and upper deck (between stringers and longitudinal beams). Frames are made in the form of powerful frames, spaced from one another by 1.5-2.5 m and cut at the intersection with longitudinal ties. This system of recruitment in its pure form is currently used only on oil tankers that do not have a second bottom.

Modern warships are built mainly according to a mixed recruitment system (Fig. 1.3): the set of the bottom, second bottom and decks is made longitudinal; a set of sides and extremities of the ship - transverse.


Rice. 1.3. Hull of the ship of the mixed recruitment system:
1 - deck belt; 2 - longitudinal beam; 3 - deck stringer; 4 - beam knitsa; 5- frame; 6 - sheerstrake; 7 - beams; 8 - side belts; 9 - side stringer; 10 - cheekbone; 11 - flora; 12 - bottom stringer; 13 - zygomatic belt; 14 - bottom belt; 15 - sheet pile belt; 16 - keel belt; 17 - vertical keel; 18 - flooring of the second bottom; 19 - longitudinal waterproof bulkhead


Regardless of the framing system, the hull must have strong connections in all three directions (longitudinal, transverse and vertical) in order to reliably withstand the forces acting on the ship. Depending on the purpose and location of the hull parts, a set of bottoms, a set of sides, a set of decks, etc. are distinguished.

bottom set- overlap, consisting of mutually intersecting longitudinal and transverse ties, called stringers and floors, respectively. In the middle of the set, coinciding with the diametrical plane of the ship, a vertical keel is installed - the main longitudinal connection of the bottom set, which perceives the forces that arise during the longitudinal bending of the ship.


Rice. 1.4. Vertical keel design:
a, b - destroyers; in - cruisers; g - keel beam of a large ship


K and l runs along the entire length of the ship. The design of the keels depends on the class of ships. On fig. 1.4 shows the design of the keels for some ships. Previously, on large ships, the vertical keel was sometimes replaced by two stringers that formed the keel beam. On ships built recent years the keel beam is usually replaced by a vertical keel with reinforced lining, sheathing and inner bottom (Fig. 1.5). In the bow and stern ends of the ship, the keel is connected to the stem and stern. Sometimes a horizontal sheet is installed above the vertical keel, which is called the horizontal keel.


Rice. 1.5. Welded construction of the keel of a large ship


Bottom stringers - longitudinal beams running parallel to the keel and together with it providing the longitudinal strength of the hull. By design, stringers are riveted or welded beams of various sections. The number of stringers on each side depends on the size of the ship. Approximately on destroyers there are 3 stringers, on cruisers - 4-5. Towards the bow and stern, the number of stringers decreases, as the width of the bottom of the ship decreases. When the bottom goes to the side of the ship, one stringer is placed on board, such stringers are called cheekbones.

Flores - vertical steel sheets that are welded to the vertical keel, run across the ship and form part of the frame frame. They are impenetrable and permeable. The first are installed to delimit the double bottom compartments and ensure the watertightness of the compartments. The latter have oval cutouts to facilitate construction, provide passage and lay pipes in the double bottom compartments.

Lateral keels (Fig. 1.6) are made to reduce the span of the ship during side roll and partially play the role of a longitudinal connection. Lateral keels in width do not go beyond the dimensions of the hull. Their design is varied.


Rice. 1.6. Side Keels:
a - the location of the keel; b, c - keel designs


board set- continuation of the set of the bottom; consists of side stringers and frames.

Side stringers are laid along the entire length of the ship, from bow to stern, and are strong beams with stiffeners. They connect the side branches of the frames, perceive the load from them and transfer it to the transverse bulkheads. Sometimes additional stiffeners are placed between the stringers.

Frames - transverse ribs of the ship's hull connected to the decks, zygomatic stringers and bottom floors. They can cut on each deck or pass through decks without being cut. The connection of the frames with the transverse beams of the set of decks is carried out with the help of brackets. Structural execution of frames can be varied: from squares and sheet strips to riveted and I-beams, and, finally, trusses (frame frames). The spacing of the skin between adjacent frames is called spacing. In our military shipbuilding, the system of numbering frames from bow to stern has been adopted; the stem is taken as zero. The middle frame along the length of the ship is conditionally called the midship frame (midship).

deck set- a system of intersecting transverse and longitudinal beams. Beams of the main direction are longitudinal beams. They are through, they cut the transverse beams and are attached to them with knees. Transverse beams and half-beams are located at a distance equal to spacing from one another and are attached to the frames with knits. To communicate with the premises located below the decks, holes (hatches) are cut in the latter, which are bordered along the perimeter above the deck by vertical waterproof sheets called coamings (Fig. 1.7). Longitudinal beams are placed under the decks, supporting the transverse beams of the decks, which are called carlings.


Rice. 1.7. The layout of carlings and coamings:
1 - deck sheet; 2 - coaming; 3 - carlings; 4 ~ cross beams


L yu to and are round and rectangular. Each manhole cover has seals and a rubber rim to ensure watertightness. According to their purpose, hatches are divided into entrance, cargo and light hatches. The movement of personnel through the hatches is carried out along the ladders (ladders of light construction). Ladders serve to communicate between decks; are inclined and vertical. Inclined ladders, as a rule, have handrails made of metal pipes; vertical - installed in mines, emergency gatherings (emergency, spare), at the exits from the engine and boiler rooms, ammunition cellars, etc.

Mines (fig. 1.8) - pipes of a special design (usually quadrangular section) passing through the spaces between decks. On the upper (lower) deck, the shaft has a neck with a waterproof cover on the wing or wing.

Rice. 1.8. Waterproof mine


When heavy local cargo is located on the deck - gun mounts, masts, deck mechanisms, etc. - pillars are installed under them in the spaces between decks (Fig. 1.9), which are calculated for the weight of decks with a set and cargo located on decks. Pillers come in various designs: permanent and removable.


Rice. 1.9. Welded tubular pillers


Set at the ends of the ship. The transverse rigidity of the extremities of the ship is given by the frames, floors and beams, which work together with the decking and plating of the sides, as well as the transverse bulkheads, which are placed (like the frames) at the extremities more often than in the middle part of the ship. To give strength to the converging edges of the sheets of side and bottom plating, stems are installed along with the set and create a rigid structure for the ends of the ship. At the bow of the ship there is a stem, which is made in the form of a forging, casting or welded structure. It is able to withstand the impact of waves, ice and floating objects. The stern end of the ship ends with a cast part - the stern pin - not m. The shape and design of the stems depend on the purpose and size of the ship, the number of propellers, the type of rudder, etc.

The shell of the ship make up the outer skin (bottom and side) and decking.

The outer skin is a waterproof shell that separates the internal volume of the ship from the water and serves simultaneously to ensure the ship's longitudinal and transverse strength. It consists of a series of belts made up of separate sheets and located along the ship. The connection of two sheets of one belt forms a joint; the connection of the belts is the groove of the outer skin. Sheathing sheets are connected in various ways: butt, overlap, edge to edge (herringbone), smooth, on planks, etc. Depending on the location of the outer sheathing belt, they are called: tongue and groove, bottom, cheekbone, side, ice sheerstrake (Fig. 1.10) Usually, the sheet piling belt (adjacent to the keel) and the sheerstrek (sheathing belt at the beams of the upper continuous deck) are made thicker than the other belts to increase the overall longitudinal strength of the ship. On warships, in addition, the plating is often doubled along the keel track, waterline (ice belt), under anchor hawses, in the area of ​​propellers.


Rice. 1.10. The location of the belts of the outer skin:
1 - sheerstrake; 2 - ice; 3 - onboard; 4 - zygomatic; 5 - bottom; 6 - sheet pile; 7 - keel


On the deck, the deck limits the internal volume of the ship from above and consists of sheets resting on the deck set. Deck flooring is made from sheets of maximum length, which are located along the long side of the ship. The outer deck sheet, running parallel to the side contour, is called the deck stringer and serves to ensure the longitudinal strength of the ship. Throughout the deck, with the exception of the area of ​​the extremities of the ship, it has a thickness 20-30% greater than the adjacent deck deck belts. The usual thickness of the belts adjacent to the deck stringer: for small ships - 4; destroyers - 5; cruisers - 7-8 mm. The smallest thickness of the deck is determined by the conditions of durability, but must be at least 4 mm. The combination of sheets and sets is the actual deck.

The hull of the ship to accommodate equipment, weapons, cargo and personnel, as well as to ensure unsinkability, fire safety and strength, is divided in height into a number of decks and platforms. According to the location on the ship, the decks are called upper, middle and lower (Fig. 1.11).


Rice. 1.11. Ship decks:
1 - outer bottom; 2 - the second, or inner, bottom; 3 - third bottom; 4 - second platform; 5 - the first platform; 5 - lower deck; 7 - middle deck; 8 - upper deck; 9 - forecastle deck; 10 - superstructure deck


The platforms pass under the lower deck at the ends of the ship and not along the entire length of the ship, but are interrupted and in this way differ from the decks. Platforms are counted from top to bottom. The number of decks and platforms depends on the design, purpose and size of the ship.

Upper deck(main) is a kind of roof and withstands the greatest tensile and compression stresses during the longitudinal bending of the hull, stresses from transverse compression of the hull, local pressure of loads, powder gases during firing and water that has appeared on the deck. To reduce flooding during waves and thereby improve the seaworthiness of the ship, the deck usually has a sheer, i.e., a rise from the middle part to the bow and stern (Fig. 1.12). In the transverse direction, the upper deck has a deflection, i.e., a bulge that provides water flow to the sides and increases the longitudinal rigidity of the deck. Directly on the upper deck, as well as on special foundations and foundations, various purposes and types of superstructures, deckhouses, bridges, weapons, deck devices, ship control posts and other equipment are placed, masts and chimneys are removed.


Rice. 1.12. Scheme of sheer and deflection of the deck:
a - sheer; b, c, d - deflection at various sections along the length of the ship


The upper deck is conditionally divided into sections, which are called: b a c - the section of the upper deck from the stem to the foremast or conning tower; w to a f y t - from the fore mast or conning tower to the main mast or aft superstructures inclusive; yut - from the main mast or stern superstructures to the cut of the stern. Some warships, many auxiliary vessels have additional decks: a forecastle above the forecastle; waist - spardek; yutom - poop.

On the upper deck, a waterway (gutter) and a scupper system are installed along the sides to remove water from the deck, superstructures and platforms. To make the deck less flooded with water, wave guides (breakwaters) and visors are installed on the forecastle (forecastle).

Deck superstructures- parts of the ship's hull located on some part of the upper deck along the entire width of the ship and forming closed volumes on it, intended for use as residential and various service premises. In accordance with the division of the upper deck into sections of the superstructure located on it, they are called bow (tank), middle and stern (poop). The bow superstructure (forecastle) also serves to increase the height of the bow of the ship's hull.

Usually, rooms located above the upper deck do not reach the side. Therefore, superstructures are conditionally called those that are located on a relatively large length of the ship, and cuttings are short superstructures. R o s t r y - open superstructure; they are a lattice (sometimes solid) flooring, constructed above the upper deck and resting on the middle superstructure on the inside, and on the pillars on the outside. The flooring is laid on roster beams. The rosters are designed to accommodate boats, lifeboats, rescue equipment and automatic anti-aircraft artillery.

The decks and platforms of the interior spaces are supported by beams and are calculated for their own weight and the weight of the goods placed on them. The best coating for interior decks is linoleum, which is easy to clean, gives the premises a neat appearance, and has sound and heat insulation qualities. Decks of residential cockpits located above rooms with high temperature(engine and boiler rooms) are covered with heat-insulating plates made of various insulating materials.

Rice. 1.13. Bottom set design diagram:
1, 2, 16, 17 - platform sections; 3-15 - inner bottom sections


inner bottom- steel decking over the bottom set (Fig. 1.13). In length, it covers the region of the set of a longitudinal or mixed system. In the bow and stern, where the set is most often transverse, there is no second bottom; it is being replaced by platforms. The thickness of the sheets of the inner bottom, in order to avoid rapid destruction by corrosion, is taken from 4 to 10 mm, depending on the class of the ship. In the engine and boiler rooms, the flooring is thicker. The double-bottom space is divided by floors and stringers into waterproof compartments (cages) with manholes (necks) closed with waterproof covers (Fig. 1.14). The space between the outer shell of the bottom and the second bottom (interbottom space) is used to store fuel, oil, fresh water and ballast water.


Rice. 1.14. Waterproof wing cap


Bulkheads- flat vertical structures (walls), consisting of sheets and a set; made waterproof and permeable. Transverse watertight bulkheads, dividing the internal volume of the ship along the length, form autonomous watertight compartments. Longitudinal watertight bulkheads form watertight side compartments. Watertight bulkheads prevent the spread of water entering through holes through the ship, thereby ensuring its unsinkability, and also prevent the spread of fire and poisonous substances.

The transverse watertight bulkheads that block the ship from the bottom to the upper deck are called the main ones. Semi-bulkheads, like main bulkheads, bear vertical and horizontal loads, but unlike them do not go from side to side. Secondary (permeable) bulkheads are installed between the main bulkheads, which separate the interior spaces.

Watertight doors (Fig. 1.15) are placed on watertight bulkheads and serve to enter watertight compartments. Such a door consists of a stamped metal sheet with a device for attaching sealing rubber along its perimeter and six wedge battens with individual or natural central battening. Lightweight doors that lead to superstructures and bridges have a lightweight design. They are also equipped with rubber seals that protect against the penetration of water (splash) and light (from the room).


Rice. 1.15. waterproof door