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1. Introduction

2. Performance characteristics

2.1 Main ship dimensions

2.2 Displacement

2.3 Load capacity

2.4 Capacity

2.5 Vessel speed

3. Seaworthiness

3.1 Buoyancy

3.2 Stability

3.3 Propulsion

3.4 Handling

3.6 Unsinkability

4. Sources

Introduction

A ship is a complex engineering and technical floating structure for the transportation of goods and passengers, water craft, mining, sports, as well as for military purposes.

In the Law of the Sea, a sea vessel is understood as a self-propelled or non-self-propelled floating structure, that is, an object artificially created by man, intended for permanent stay at sea in a floating state. For the recognition of a particular structure as a ship, it does not matter whether it is equipped with its own engine, whether it has a crew, whether it is moving or is predominantly in a stationary floating state. The same definition, except for the sea, applies to inland waters and rivers.

As an engineering structure designed for specific purposes, the ship has operational characteristics and seaworthiness.

Performance characteristics

The main dimensions of the ship

The main dimensions of a vessel are its linear dimensions: length, width, side height and draft.

Diametral plane (DP) - the vertical longitudinal plane of symmetry of the theoretical surface of the ship's hull.

The plane of the midship frame is a vertical transverse plane passing in the middle of the length of the vessel, on the basis of which a theoretical drawing is built.

Under the frame (Shp) is meant the theoretical line on the theoretical drawing, and the practical frame on the design drawings.

Structural waterline (DWL) - waterline corresponding to the estimated total displacement of ships.

Waterline (VL) - the line of intersection of the theoretical surface of the hull with a horizontal plane.

Aft perpendicular (CP) - the line of intersection of the diametral plane with a vertical transverse plane passing through the point of intersection of the axis of the stock with the plane of the design waterline; KP on the theoretical drawing coincides with the 20th theoretical frame.

Fore perpendicular (NP) - the line of intersection of the diametrical plane with a vertical transverse plane passing through the extreme bow point of the design waterline.

Main plane - a horizontal plane passing through the lowest point of the theoretical surface of the body without protruding parts.

On the drawings, in the descriptions, etc., the dimensions are given in length, width and height.

The dimensions of the vessels along the length are determined parallel to the main plane.

Longest length L nb - the distance measured in the horizontal plane between the extreme points of the bow and stern ends of the hull without protruding parts.

The length along the design waterline L kvl is the distance measured in the plane of the design waterline between the points of intersection of its fore and aft parts with the diametral plane.

The length between perpendiculars L PP - the distance measured in the plane of the design waterline between the bow and stern perpendiculars.

The length along any waterline L vl is measured as L kvl

The length of the cylindrical insert L c - the length of the ship's hull with a constant section of the frame.

The length of the bow point L n - is measured from the bow perpendicular to the beginning of the cylindrical insert or to the frame of the largest section (for ships without a cylindrical insert).

The length of the stern taper L to - is measured from the end of the cylindrical insert or frame of the largest section - the end of the stern of the waterline or other designated point, such as the stern perpendicular. Dimensions for the width of the vessels are measured parallel to the main and perpendicular to the diametrical planes.

Maximum width In nb - the distance measured between the extreme points of the body without protruding parts.

Width at the midship frame B is the distance measured at the midship frame between the theoretical surfaces of the sides at the level of the design or design waterline.

DWL width In kVL - the largest distance measured between the theoretical surfaces of the sides at the level of the design waterline.

Width along VL V ow is measured as V kvl.

Height dimensions are measured perpendicular to the base plane.

Side height H - vertical distance measured on the midship frame from the horizontal plane passing through the point of intersection of the keel line with the plane of the midship frame, to the side line of the upper deck.

Depth to the main deck Н Г. П - depth of the side to the uppermost solid deck.

Depth to tween deck H TV -- Depth to deck below the main deck. If there are several tween decks, then they are called the second, third, etc. deck, counting from the main deck.

Draft (T) - vertical distance measured in the plane of the midship frame from the main plane of the design or design waterline.

Draft by the bow and draft by the stern T n and T k - are measured on the bow and stern perpendiculars to any waterline.

Average draft T cf - measured from the main plane to the waterline in the middle of the ship's length.

Fore and aft sheer h n and h k - smooth rise of the deck from the midship to the bow and stern; the magnitude of the rise is measured on the bow and stern perpendiculars.

Beam sag h b - the difference in height between the edge and the middle of the deck, measured at the widest point of the deck.

Freeboard F is the vertical distance measured at the side at the middle of the vessel's length from the upper edge of the deck line to the upper edge of the corresponding load line.

If necessary, other dimensions are also indicated, such as, for example, the largest (overall) height of the vessel (height of a fixed point) from the load waterline when empty for passage under bridges. Usually they are limited to indicating the length - the largest and between the perpendiculars, the width at the midship frame, the height of the side and draft. In cases of application of international Conventions - on the safety of life at sea, on the load line, measurement, classification and construction of ships - they are guided by the definitions and dimensions established in these Conventions or Rules.

Displacement

Displacement is one of the main characteristics of a vessel, which indirectly characterizes its size.

Distinguish the following displacement values:

mass or weight and volume,

surface and underwater (for submarines and submarines),

· light displacement, standard, normal, full and maximum.

The total displacement is equal to the sum of the light displacement and the deadweight.

The displacement of a ship is the amount of water displaced by the underwater part of the ship's hull. The mass of this amount of water is equal to the weight of the entire ship, regardless of its size, material and shape. (According to the law of Archimedes)

Ш Mass (weight) displacement is the mass of a vessel afloat, measured in tons, equal to the mass of water displaced by the vessel.

Since the mass of the vessel can vary widely during operation, two concepts are used in practice:

Displacement in full load D, equal to the total mass of the ship's hull, all mechanisms, devices, cargo, crew passengers and ship stores at the maximum allowable draft;

Lightweight displacement D0, equal to the mass of the vessel with equipment, permanent spare parts and supplies, with water in boilers, machinery and pipelines, but without cargo, passengers, crew and without fuel and other supplies.

Ш Volumetric displacement - the volume of the underwater part of the vessel below the waterline. With a constant weight displacement, the volumetric displacement varies depending on the density of the water.

That is, the volume of fluid displaced by the body is called volumetric displacement.

The center of gravity of volumetric displacement W is called the center of displacement.

Standard displacement (standard displacement) - the displacement of a fully equipped ship (vessel) with a crew, but without reserves of fuel, lubricants and drinking water in tanks.

Normal displacement - Displacement equal to the standard displacement plus half the fuel, lubricants and potable water in the tanks.

Full displacement (loaded displacement, full load displacement, designated displacement) - a displacement equal to the standard displacement plus full reserves of fuel, lubricants, potable water in tanks, cargo.

Displacement reserve - an excess addition to the mass of the vessel, taken during design, to compensate for the possible excess of the mass of its structure during construction.

The largest displacement is a displacement equal to the standard displacement plus the maximum reserves of fuel, lubricants, drinking water in tanks, cargo.

Underwater displacement - the displacement of a submarine (batyscaphe) and other underwater vessels in a submerged position. Exceeds the surface displacement by the mass of water taken when immersed in the main ballast tanks.

Surface displacement - the displacement of a submarine (bathyscaphe) and other underwater vessels in a position on the surface of the water before immersion or after surfacing.

load capacity

Carrying capacity is one of the most important operational characteristics - the mass of cargo for which the ship is designed to carry - the weight of various types of cargo that the ship can carry, provided that the design landing is maintained. Measured in tons. There is net tonnage and deadweight.

Net carrying capacity (Useful carrying capacity) is the total mass of the payload carried by the ship, i.e. the mass of cargo in the holds and the mass of passengers with luggage and fresh water and provisions intended for them, the mass of fish caught, etc., when loading the vessel according to the design draft.

Deadweight (full load capacity) - DWT - deadweight tons. Represents the total mass of the payload carried by the vessel, which is the net carrying capacity, as well as the mass of fuel, water, oil, crew with luggage, provisions and fresh water for the crew when the vessel is loaded to the design draft. If a ship with cargo takes on liquid ballast, then the mass of this ballast is included in the deadweight of the ship. Deadweight at summer load line draft in sea ​​water is an indicator of the size of a cargo ship and its main operational characteristic.

Carrying capacity should not be confused with carrying capacity, and even more so with the register capacity (registered carrying capacity) of the vessel - these are different parameters measured in different quantities and having different dimensions.

Capacity

In addition to determining the carrying capacity of a ship in units of weight (now usually in metric tons) and measuring the total weight of a ship with a displacement parameter, a historical tradition has developed to measure the internal volumes of a ship. This parameter is only used for civil ships.

The capacity of the ship is the volumetric characteristic of the ship's premises. Cargo capacity and register capacity should not be confused. For passenger and cargo-passenger ships, there is also the “passenger capacity” parameter.

The parameters of capacity (cargo capacity), carrying capacity (including deadweight) and displacement are not related to each other and are generally independent (although for one class of ships there are coefficients that indirectly relate one parameter to another).

Gross tonnage (BRT) is the total tonnage of all watertight enclosed spaces; thus, it indicates the total internal volume of the vessel, which includes the following components:

The volume of rooms under the measuring deck (the volume of the hold below deck);

The volume of rooms between the measuring and upper decks;

The volume of enclosed spaces located on the upper deck and above it (superstructures);

Amount of space between hatch coamings.

Gross tonnage does not include the following: enclosed spaces, if they are intended and suitable exclusively for the named purposes and are used only for this:

Premises in which there are power and electric power plants, as well as air intake systems;

Auxiliary machinery spaces that do not serve the main engines (for example, refrigeration plant rooms, distribution substations, elevators, steering gears, pumps, processing machines on fishing vessels, chain boxes, etc.);

A ship that has openings in the upper deck without strong watertight closures (gauge hatches and openings) is called a sheltered ship or a ship with a hinged deck; it has a smaller register capacity because of such holes. Closed interior volumes in open spaces that have strong watertight closures are included in the measurement. The condition for exclusion from the measurement of open spaces is that they do not serve to accommodate or serve crew and passengers. If the upper deck of double-deck or multi-deck ships and bulkheads of superstructures are fitted with strong watertight closures, the space between decks below the upper deck and superstructure spaces are included in the gross tonnage. Such vessels are called full-set and have a maximum allowable draft.

Net tonnage (NRT) is the usable volume for accommodating passengers and cargo, i.e. commercial volume. It is formed by subtracting the following components from the gross tonnage:

Premises for the crew and navigators;

navigation facilities;

Premises for skipper stores;

Ballast water tanks;

Engine room (power plant premises).

Deductions from gross tonnage are made according to certain rules, in absolute terms or as a percentage. The condition for the deduction is that all these spaces are included in gross tonnage first. In order to be able to check whether the tonnage certificate is genuine and belongs to this vessel, it indicates the dimensions of the identity (identification dimensions) of the vessel, which are easy to verify.

The cargo capacity of a vessel is the volume of all holds in cubic meters, cubic feet, or in 40 cubic foot "barrels". Speaking about the capacity of holds, the capacity is distinguished by piece (bales) and bulk (grain) cargo. This difference follows from the fact that in one hold, due to floors, frames, stiffeners, bulkheads, etc., bulk cargo can be placed more than piece cargo. The general cargo hold is approximately 92% of the bulk cargo hold. The calculation of the ship's capacity is made by the shipyard; capacity is indicated on the capacity diagram, and it has nothing to do with the official measurement of the ship. Specific cargo capacity is the ratio of the capacity of the holds to the mass of the payload. Since the mass of the payload is determined by the mass of the necessary operational materials, the specific cargo capacity is subject to slight fluctuations. General cargo ships have a specific cargo capacity of approximately 1.6 to 1.7 m3/t (or 58 to 61 cubic feet).

Vessel speed

Speed ​​is one of the most important operational characteristics of a vessel and one of the most important tactical and technical characteristics of a vessel, which determines the speed of its movement.

The speed of ships is measured in knots (1 knot is equal to 1.852 km / h), the speed of inland navigation vessels (river, etc.) is measured in kilometers per hour.

There are the following types of vessel speed:

Ш The absolute speed of the ship is the speed measured by the distance traveled by the ship per unit time relative to the ground (an immovable object) along the line of the ship's path.

Ø The safe speed of the vessel is the speed at which appropriate and necessary action can be taken to avoid collision.

Ш Cruising (for warships also the combat economic speed of the ship) is a speed that requires a minimum fuel consumption per mile traveled with normal displacement and the operation of ship and combat equipment in a mode that ensures full technical readiness of the main mechanisms for the development of full combat speed.

Ш The general speed of the ship is measured by the distance traveled by the ship per unit of time along the general course.

Ш Permissible speed of the vessel - the established maximum speed, limited by the conditions of the combat mission being performed, the situation or the rules of navigation (when trawling, towing, in waves or shallow water, in accordance with the rules of the raid service or a mandatory port order)

Ш The highest speed of the ship (or maximum) develops when the power plant (Main Power Plant) of the ship is operating in forced mode while ensuring the full combat readiness of the ship. Prolonged forcing of the power plant can lead to its failure and loss of speed, as a result of which the ship will reach top speed resorted to in exceptional cases.

Ш The lowest speed of the vessel (or minimum) - the speed at which the vessel can still be kept on course (controlled by the rudder).

Ш The relative speed of the ship is measured by the distance traveled by the ship per unit time relative to the water.

Ш Full combat speed of the vessel (or full speed) is achieved when the power plant is operating in full power mode (without afterburner) with the simultaneous operation of all combat and technical means of the vessel, ensuring the full combat readiness of the vessel.

Ш The economic speed of the vessel (or technical and economic) is the speed achieved when the power plant is operating in the economic mode. At the same time, the task of the lowest fuel consumption per mile traveled is achieved while simultaneously ensuring the established combat readiness and domestic needs of the vessel.

Squadron speed of a ship (or assigned) - the speed of a formation or a group of ships, established in each individual case based on the requirements of the assigned task, the situation in the transition area, navigation and hydrometeorological conditions.

Seaworthiness

ship speed carrying capacity unsinkability

Seaworthiness must be possessed by both civilian ships and warships.

The study of these qualities with the use of mathematical analysis is carried out by a special scientific discipline - the theory of the ship.

If a mathematical solution of the problem is impossible, then they resort to experience in order to find the necessary dependence and verify the conclusions of the theory in practice. Only after a comprehensive study and testing on the experience of all the seaworthiness of the vessel, they begin to create it.

Seaworthiness is studied in two sections: statics and dynamics of the vessel. Statics studies the laws of equilibrium of a floating vessel and the qualities associated with it: buoyancy, stability and unsinkability. Dynamics studies the vessel in motion and considers its qualities such as handling, pitching and propulsion.

Buoyancy

The buoyancy of a vessel is its ability to stay on the water at a certain draft, carrying the intended cargo in accordance with the purpose of the vessel.

Buoyancy reserve

The ability of a ship to stay on the water at a certain draft, while carrying a load, is characterized by a buoyancy margin, which is expressed as a percentage of the volume of watertight compartments above the waterline to the total watertight volume. Any violation of the impermeability leads to a decrease in the buoyancy margin.

The equilibrium equation in this case has the form:

P = r (Vo?Vn) or: P = r V

where P is the weight of the vessel, g is the density of the water, V is the submerged volume, and is called the basic buoyancy equation.

It follows from it:

Ш At a constant density r, a change in the load P is accompanied by a proportional change in the immersed volume V until a new equilibrium position is reached. That is, with an increase in the load, the vessel “sits” deeper into the water, with a decrease, it floats higher;

Ш At a constant load P, a change in density r is accompanied by an inversely proportional change in the submerged volume V. Thus, a ship sits deeper in fresh water than in salt water;

III Change in volume V, other things being equal, is accompanied by a change in draft. For example, when ballasting with outboard water or emergency flooding of compartments, it can be assumed that the ship did not take the cargo, but reduced the submerged volume, and the draft increased - the ship sits deeper. When pumping water, the opposite happens.

The physical meaning of the buoyancy margin is the volume of water that the ship can take (say, when compartments are flooded) while still afloat. A buoyancy margin of 50% means that the waterproof volume above the waterline is equal to the volume below it. Vessels are characterized by reserves of 50-60% and more. It is believed that the larger the supply was obtained during construction, the better.

neutral buoyancy

When the volume of water received is exactly equal to the buoyancy margin, buoyancy is considered to be lost - the margin is 0%. Indeed, at this moment the ship is sinking along the main deck and is in an unstable state, when any external influence can cause it to go under water. And as a rule, there is no shortage of influences. In theory, this case is called neutral buoyancy.

negative buoyancy

When receiving a volume of water greater than the buoyancy margin (or any cargo that is larger in weight), it is said that the ship receives negative buoyancy. In this case, it is unable to swim, but can only sink.

Therefore, a mandatory reserve of buoyancy is established for the vessel, which it must have in an intact state for safe navigation. It corresponds to full displacement and is marked with a waterline and/or load line.

Straightness hypothesis

To determine the effect of variable loads on buoyancy, an assumption is used under which it is considered that the acceptance of small (less than 10% of displacement) loads does not change the area of ​​the effective waterline. That is, the change in draft is considered as if the hull is a straight prism. Then the displacement directly depends on the draft.

Based on this, the settlement change factor is determined, usually in t/cm:

where S is the area of ​​the effective waterline, q means the amount of change in load in tons required to change the draft by 1 cm. When calculated backwards, it allows you to determine if the buoyancy margin has not gone beyond the permissible limits.

Stability

Stability is the ability of the vessel to resist the forces that caused it to tilt, and after the termination of these forces, return to its original position.

Vessel inclinations are possible for various reasons: from the action of oncoming waves, due to asymmetric flooding of compartments during a hole, from the movement of goods, wind pressure, due to the receipt or expenditure of goods, etc.

Stability types:

Ш Distinguish between initial stability, i.e. stability at small angles of heel, at which the edge of the upper deck begins to enter the water (but not more than 15 ° for high-sided surface ships), and stability at high inclinations.

Ш Depending on the plane of inclination, there are transverse stability with roll and longitudinal stability with trim. Due to the elongation of the shape of the ship's hull, its longitudinal stability is much higher than the transverse one, therefore, for the safety of navigation, it is most important to ensure proper transverse stability.

Ш Depending on the nature of the acting forces, static and dynamic stability are distinguished.

Static stability - considered under the action of static forces, that is, the applied force does not change in magnitude.

Dynamic stability - considered under the action of changing (that is, dynamic) forces, such as wind, sea waves, cargo movement, etc.

Initial stability

If the vessel, under the influence of the external heeling moment of the MKR (for example, wind pressure), rolls at an angle and (the angle between the initial WL0 and the current WL1 waterlines), then, due to a change in the shape of the underwater part of the vessel, the center of magnitude C will move to point C1 (Fig. 2 ). The support force y V will be applied at point C1 and directed perpendicular to the effective waterline WL1. Point M is located at the intersection of the diametrical plane with the line of action of the support forces and is called the transverse metacenter. The ship's weight force P remains at the center of gravity G. Together with the force yV, it forms a pair of forces that prevents the ship from tilting by the heeling moment of the MKR. The moment of this pair of forces is called the restoring moment of the MW. Its value depends on the shoulder l=GK between the forces of weight and support of the tilted vessel:

MB \u003d Pl \u003d Ph sin and,

where h is the elevation of the point M above the CG of the vessel G, called the transverse metacentric height of the vessel.

Fig.2. The action of forces when the ship rolls

It can be seen from the formula that the value of the restoring moment is the greater, the greater h. Therefore, the metacentric height can serve as a measure of stability for a given vessel.

The value h of a given ship at a certain draft depends on the position of the center of gravity of the ship. If the load is positioned so that the ship's center of gravity takes a higher position, then the metacentric height will decrease, and with it the static stability arm and the restoring moment, i.e., the ship's stability will decrease. With a decrease in the position of the center of gravity, the metacentric height will increase, the stability of the vessel will increase.

The metacentric height can be determined from the expression h = r + zc - zg, where zc is the elevation of the CV over the OL; r -- transverse metacentric radius, i.e., the elevation of the metacenter above the CV; zg -- the elevation of the ship's CG above the main one.

in a built ship, the initial metacentric height is determined empirically - by heeling, i.e., the transverse inclination of the ship by moving a load of a certain weight, called roll-ballast.

Stability at high angles of heel

Fig.3. Diagram of static stability.

As the ship's roll increases, the restoring moment first increases, then decreases, becomes equal to zero, and then not only does not prevent the inclination, but, on the contrary, contributes to it (Fig. 3)

Since the displacement for a given load state is constant, the restoring moment changes only due to a change in the lateral stability arm lst. According to the calculations of transverse stability at large angles of heel, a diagram of static stability is built, which is a graph expressing the dependence of lst on the angle of heel. The static stability diagram is built for the most typical and dangerous cases of ship loading.

Using the diagram, it is possible to determine the heeling angle from a known heeling moment or, conversely, to find the heeling moment from a known heeling angle. The initial metacentric height can be determined from the static stability diagram. To do this, a radian equal to 57.3 ° is laid off from the origin of coordinates, and the perpendicular is restored to the intersection with the tangent to the curve of the stability shoulders at the origin. The segment between the horizontal axis and the intersection point on the scale of the diagram will be equal to the initial metacentric height.

Influence of liquid cargoes on stability. If the tank is not filled to the top, i.e., it has a free surface of the liquid, then when tilted, the liquid will overflow in the direction of the list and the ship's center of gravity will shift in the same direction. This will lead to a decrease in the stability arm and, consequently, to a decrease in the restoring moment. Moreover, the wider the tank, in which there is a free surface of the liquid, the more significant will be the decrease in lateral stability. To reduce the influence of the free surface, it is advisable to reduce the width of the tanks and strive to ensure that during operation there is a minimum number of tanks with a free liquid surface

Influence of bulk cargoes on stability. When transporting bulk cargo (grain), a slightly different picture is observed. At the beginning of the inclination, the load does not move. Only when the angle of heel exceeds the angle of repose does the cargo begin to spill. In this case, the spilled cargo will not return to its previous position, but, remaining at the side, will create a residual roll, which, with repeated heeling moments (for example, squalls), can lead to loss of stability and capsizing of the vessel.

To prevent spillage of grain in the holds, suspended longitudinal semi-bulkheads are installed - shifting boards or bags of grain are laid on top of the grain poured in the hold - bagging the cargo.

Effect of a suspended load on stability. If the cargo is in the hold, then when it is lifted, for example, by a crane, there is, as it were, an instantaneous transfer of the cargo to the suspension point. As a result, the ship's CG will shift vertically upward, which will lead to a decrease in the righting moment arm when the ship receives a roll, i.e., to a decrease in stability. In this case, the decrease in stability will be the greater, the greater the mass of the load and the height of its suspension.

Propulsion

The ship's ability to move environment with a given speed at a certain power of the main engines and the corresponding propulsion is called propulsion.

The vessel moves on the border of two media - water and air. Since the density of water is about 800 times the density of air, the resistance of water is much greater. air resistance. The water drag force consists of frictional drag, form drag, wave drag, and projecting drag.

Due to the viscosity of water, friction forces arise between the hull of the vessel and the layers of water closest to the hull, to overcome which a part of the power of the main engine is expended. The resultant of these forces is called frictional resistance RT. Friction resistance also depends on speed, on the wetted surface of the ship's hull and on the degree of roughness. The amount of roughness is affected by the quality of the coloring, as well as the fouling of the underwater part of the hull by marine organisms. So that the friction resistance does not increase for this reason, the ship is subjected to periodic docking and cleaning of the underwater part. Friction resistance is determined by calculation.

When a viscous fluid flows around the ship's hull, the hydrodynamic pressures are redistributed along its length. The resultant of these pressures, directed against the movement of the vessel, is called the form resistance RФ. Form resistance depends on the speed of the vessel and on its shape. With a poorly streamlined shape, vortices are formed in the stern of the vessel, which leads to a decrease in pressure in this area and an increase in the drag of the vessel's shape. Wave resistance RВ arises due to the formation of waves in the zones of high and low pressure when the ship is moving. Part of the energy of the main engine is also spent on wave formation. Wave resistance depends on the speed of the vessel, the shape of its hull, as well as on the depth and width of the fairway. The resistance of the protruding parts RHF depends on the friction resistance and on the shape of the protruding parts (rudders, bilge keels, propeller shaft brackets, etc.). Form resistance and wave resistance are combined into residual resistance, which can only be calculated approximately. For exact definition residual resistance values ​​are used to test ship models in the test basin.

Controllability

Handling is the ability of a vessel to be agile and stable on a course. Agility is the ability of the vessel to obey the action of the rudder, and stability on the course is the ability to maintain a given direction of movement. Due to the influence of various disturbing factors (waves, wind) on the movement of the vessel, constant intervention of the helmsman is required to ensure stability on the course. Thus, the qualities that characterize the ship's controllability are contradictory. So, the more agile the ship, i.e., the faster it changes the direction of its movement when the rudder is turned, the less stable it is on the course.

When designing a ship, the optimal value of a particular quality is chosen depending on the purpose of the ship. The main quality of passenger and cargo ships making long-distance voyages is course stability, and that of tugboats is agility.

The ability of the vessel to spontaneously deviate from the course under the influence of external forces is called yaw.

Rice. 4 Scheme of the forces acting on the ship when the rudder is shifted.

To ensure the required controllability, one or more rudders are installed in the stern of the vessel (Fig. 4). If, on a ship moving at a speed v, the rudder is shifted to an angle b, then the pressure of the oncoming water flow will begin to act on one side of the rudder - the resultant of the hydrodynamic forces P, applied at the center of pressure and directed perpendicular to the surface of the rudder. Let us apply mutually balanced forces P1 and P2, equal and parallel to P, at the ship's center of gravity. The forces P and P2 form a pair of forces, the moment of which MVR turns the ship to the right, MVR = Pl, where the arm of the pair is l = GA cosb + a.

We decompose the force P1 into components Q = P1 cosb = P cosb and R = P1 sinb = Psinb. The force Q causes drift, i.e., the movement of the vessel perpendicular to the direction of movement, and the force R reduces its speed.

Fig.5. Elements of the ship's circulation: DC - circulation diameter; DT - tactical circulation diameter; c - drift angle.

Thus, immediately after the rudder is put on board, the ship's CG will begin to describe a curve in the horizontal plane, gradually turning into a circle called circulation (Fig. 5). The diameter of the circle Dц, which will begin to describe the center of gravity of the vessel after the start of the steady circulation is called the diameter of the circulation. The distance between the DP before the start of the circulation and after the ship has turned 180 ° is the tactical diameter of the circulation DT. A measure of the agility of a vessel is the ratio of the diameter of the circulation to the length of the vessel. The angle between the ship's DP and the tangent to the ship's trajectory during circulation drawn through the ship's center of gravity is called the drift angle c.

When moving on the circulation, the ship rolls on the side opposite the rudder shift, under the action of the centrifugal inertia force applied at the center of gravity of the ship, and the hydrodynamic forces applied to the underwater part of the ship and the rudder. To ensure good controllability at low speeds (in cramped water areas, when mooring), when a conventional steering wheel is ineffective, active control tools are used.

Rolling is called the oscillatory movements that the ship makes near the position of its equilibrium.

Oscillations are called free (on calm water) if they are made by the vessel after the termination of the forces that caused these oscillations (wind squall, jerk of the towline). Due to the presence of resistance forces (air resistance, water friction), free oscillations gradually damp out and stop. Oscillations are called forced if they are performed under the action of periodic perturbing forces (incoming waves).

Rolling is characterized by the following parameters (Fig. 6):

W amplitude and - the largest deviation from the equilibrium position;

Ш span - the sum of two successive amplitudes;

W period T - the time of making two full swings;

W acceleration.

Fig.6. Rolling parameters: u1 and u2 amplitudes; u1+ u2 range.

Rolling complicates the operation of machines, mechanisms and instruments due to the impact of emerging inertia forces, creates additional loads on the strong bonds of the ship's hull, and has a harmful physical effect on people.

Distinguish side, keel and vertical pitching. When rolling, oscillations occur around the longitudinal axis passing through the center of gravity of the vessel, while keel - around the transverse. Rolling with a short period and large amplitudes becomes gusty, which is dangerous for mechanisms and is hard to bear by people.

The period of free oscillations of the ship in calm water can be determined by the formula T \u003d c (B / vh), where B is the width of the ship, m; h -- transverse metacentric height, m; c - coefficient equal to 0.78 - 0.81 for cargo ships.

It can be seen from the formula that with an increase in the metacentric height, the pitching period decreases. When designing a vessel, they strive to achieve sufficient stability with moderate rolling smoothness. When sailing in waves, the navigator must know the period of the vessel's own oscillations and the period of the wave (the time between two neighboring crests running on the vessel). If the period of the vessel's natural oscillations is equal to or close to the period of the wave, then a resonance phenomenon occurs, which can lead to the capsizing of the vessel.

When pitching, it is possible either to flood the deck, or when the bow or stern is exposed, they hit the water (slamming). In addition, the accelerations that occur during pitching are much greater than when onboard. This circumstance should be taken into account when choosing mechanisms installed in the bow or stern.

Heave is caused by a change in the supporting forces as the wave passes under the vessel. The heave period is equal to the wave period.

To prevent undesirable consequences from the action of rolling, shipbuilders use means that contribute, if not to a complete cessation of rolling, then at least to moderate its scope. This problem is especially acute for passenger ships.

To moderate pitching and flood the deck with water, a number of modern ships make a significant rise in the deck in the bow and stern (sheer), increase the collapse of the bow frames, and design ships with a forecastle and poop. At the same time, water-breaking visors are installed in the bow on the tank.

To moderate the roll, passive uncontrolled or active controlled roll stabilizers are used.

Fig.7. The scheme of action of the zygomatic (lateral) keels.

The passive dampers include bilge keels, which are steel plates installed over 30-50% of the length of the vessel in the chin area along the water flow line (Fig. 7). They are simple in design, reduce the pitching amplitude by 15-20%, but provide significant additional water resistance to the movement of the vessel, reducing the speed by 2-3%.

Passive tanks are tanks installed along the sides of the vessel and interconnected at the bottom by overflow pipes, at the top - by an air channel with an uncoupling valve that regulates the overflow of water from side to side. It is possible to adjust the cross-section of the air channel in such a way that the liquid during rolling will overflow from side to side with a delay and thereby create a heeling moment that counteracts inclination. These tanks are effective in long-period pitching regimes. In all other cases, they do not moderate, but even increase its amplitude.

In active tanks (Fig. 8), water is pumped by special pumps.

Fig.8. Active sedative tanks.

Currently, active side rudders (Fig. 9) are most often used on passenger and research ships, which are conventional type rudders installed in the widest part of the vessel slightly above the cheekbone in an almost horizontal plane. With the help of electro-hydraulic machines, controlled by signals from sensors that respond to the direction and speed of the ship's inclination, it is possible to change their angle of attack. So, when the vessel is tilted to starboard, the angle of attack is set on the rudders so that the resulting lifting forces created moments that were inverse to the inclination. The efficiency of the rudders on the move is quite high. In the absence of pitching, the rudders are removed into special niches in the hull so as not to create additional resistance. The disadvantages of the rudders include their low efficiency at low speeds (below 10 - 15 knots) and the complexity of the automatic control system for them.

Fig.9. Active side rudders: a - general form; b - scheme of action; c - forces acting on the side steering wheel.

There are no stabilizers to moderate pitching.

Unsinkability

Unsinkability is the ability of a ship to stay afloat, maintaining a sufficient degree of stability and a certain margin of buoyancy, when one or more compartments are flooded.

The mass of water poured into the hull changes the landing, stability and other seaworthiness of the vessel. The unsinkability of the vessel is ensured by its buoyancy margin: the greater the buoyancy margin, the more outboard water it can take while remaining afloat.

When installing longitudinal watertight bulkheads on a ship, it is necessary to carefully analyze their effect on unsinkability. On the one hand, the presence of these bulkheads can cause an unacceptable roll after the flooding of the compartment, on the other hand, the absence of bulkheads will adversely affect stability due to the large area of ​​the free water surface. Thus, the division of the ship into compartments should be such that in the event of a side hole, the buoyancy of the ship is exhausted before its stability: the ship must sink without capsizing.

To straighten the vessel, which has received a roll and trim as a result of a hole, forced counter-flooding of pre-selected compartments with the same magnitude, but with the opposite magnitude of the moments, is carried out. This operation is carried out using unsinkability tables - a document with the help of which it is possible to determine the landing and stability of the vessel after damage with a minimum expenditure of time, select compartments to be flooded, and evaluate the results of straightening before it is carried out in practice.

The unsinkability of sea vessels is regulated by the Register Rules developed on the basis of the International Convention for the Safety of Life at Sea, 1974 (SOLAS-74). In accordance with these rules, a ship is considered unsinkable if, after the flooding of any one compartment or several adjacent compartments, the number of which is determined depending on the type and size of the ship, as well as the number of people on board (usually one, and for large ships - two compartments ), the ship sinks no deeper than the margin line. In this case, the initial metacentric height of the damaged vessel must be at least 5 cm, and the maximum arm of the static stability diagram must be at least 10 cm, with a minimum length of the positive section of the diagram of 20 °.

Sources

1. http://www.trans-service.org/ - 15/12/2015

2. http://www.midships.ru/ - 15/12/2015

3. en.wikipedia.org - 12/15/2015

4. http://flot.com - 12/15/2015

5. Sizov, V. G. Theory of the ship: Tutorial for universities. Odessa, Phoenix, 2003. - 12/15/2015

6. http://www.seaships.ru - 15/12/2015

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Annotation.

7 figures, 24 pages, 7 tables.

The course paper provides an overview of scientific and technical literature, which examines the history of creation and design, technical and combat characteristics, as well as the reasons for the appearance of the light cruiser of the USSR, named after the outstanding Russian commander Field Marshal M.I. Kutuzov.

Introduction.

The Great Patriotic War dealt a huge blow to the Soviet Union. Many enterprises were destroyed because of this, the development of the country, including the Navy, was suspended and we lagged behind many countries.

In the first ten post-war years, the development of the Soviet Navy proceeded along the path of excluding obsolete ships, aircraft and coastal facilities from its composition, modernizing ships, weapons, military equipment and building new modern ships and combat equipment. The USSR, having no real technical capabilities to create a powerful ocean-going nuclear missile fleet, was forced to build ships with conventional artillery and torpedo-mine weapons. During this period, the USSR fleet retained the status of a coastal fleet and was intended mainly for solving defensive tasks. In accordance with this, the development of the project "68-bis" of the cruiser of the "Sverdlov" type was carried out. These ships were the largest cruisers in the history of the Soviet Navy and the most numerous in their subclass.

Serial construction of the lung cruisers of this type were produced in accordance with the first post-war military shipbuilding program of the USSR, adopted in 1950. By the mid-1950s, 25 units were planned for construction under the 68-bis project. Actually completed in various modifications -14 units. The cruisers of the 68-bis project were one of the largest cruising series in the world. From 1956 to mid-1960, they were the main ships of the Soviet Navy.

general characteristics historical period.

Second World War 1939-1945, unleashed by Germany, Italy in Europe and Japan in the Far East, ended in their complete defeat. The victory was achieved by the joint efforts of the countries of the anti-fascist coalition, but the decisive contribution to it was made by Soviet Union.

After the war, the United States became the leader of the capitalist world. Their competitors were either crushed or weakened. During the years of the war, the United States became the main international creditor, they penetrated into the economy of the most developed capitalist countries. The US military potential was already enormous in the mid-1940s. Their armed forces included 150 thousand different aircraft and the largest fleet in the world, which had only aircraft carriers (of various types) over 100 units. They had a monopoly on the atomic bomb. The entire arsenal of propaganda tools was aimed at glorifying American atomic omnipotence and intimidating peoples. In fact, the United States and NATO turned the World Ocean into an arena for unleashing war against the USSR and other socialist countries. In order to resist them, a powerful fleet was needed, and because of the small amount of resources, it was quite difficult to saddle it, but already in 1946 the development of the 68-bis project began, and on June 14, 1947 it was approved by the decision of the USSR Council of Ministers. Probably, "68-bis" absorbed the distant echoes of the old Russian cruisers (part of the so-called Vladivostok detachment, which raided the Japanese coast in 1904) and German lone raiders who piracy almost with impunity in the Atlantic during the first stage of World War II . The chief designer of the 68-bis project, A.S. Savichev, managed to create a new generation artillery ship. Something in the ship was from the Italians, from the German heavy cruisers of the Admiral Heater type and, of course, all the best from the 68-bis and 68-K projects. The first ship of this project was the artillery cruiser "Sverdlov", which marked the beginning of the commissioning Navy USSR large series of artillery cruisers. Summing up the shipbuilding program of 1946-1955, we can say that it was not completed due to insufficient growth production possibilities country as a whole, because it was the post-war period. But with the beginning of the 50s, great changes took place in the field of naval structures and military equipment, which for the better changed views on the composition of the armament of warships, but also on the types and classes of both submarines and surface ships.

The main goals and objectives of the creation of the ship.

In January 1947, a tactical and technical assignment was issued for the development of a project under the code "68-bis". The development of this project was carried out by TsKB-17 under the leadership of the chief designer A.S. Savicheva (saving time from development draft design refused). In 1949, at the request of the leadership of the Navy, the working draft was revised taking into account the installation of new radar stations and means of communication of the Pobeda system. The development of the LKR project under the code "68-bis" is the result of almost 15 years of work by the Central Design Bureau on the creation of Soviet LKR under the leadership of A.S. Savicheva. The cruisers of this series became the basis of the ocean fleet of the USSR, the first to go beyond the seas washing its shores, and “printed out the 30-year heyday of the USSR Navy. The main task for these cruisers was to act as part of a squadron, withdrawing light forces into an attack, supporting ship patrols and reconnaissance, as well as protecting the squadron from enemy light forces.

Resources, scientific-technical and industrial-production base for the creation of a cruiser.

The 68bis project was approved in 1947. In 1940, the weapons adopted by the Soviet Navy were used to a limited extent during the Great Patriotic War. In the post-war period, light cruisers were armed with these guns. By 1940 standards, the MK-5bis was an excellent weapon. It had a sufficient rate of fire and had excellent ballistic characteristics for its caliber. However, by the standards of the 1950s, when the 68K and 68-bis cruisers armed with this artillery system began to enter service, it could hardly be called modern. The main drawback of the gun was its low rate of fire, caused by the use of cap loading. While American light cruisers fired up to 12 rounds per minute. At the same time, all new Western artillery systems had a significant elevation angle and could conduct anti-aircraft fire. Although the Soviet gun was superior to its Western counterparts in terms of firing range. In addition, the powerful artillery of the cruisers could also be used to neutralize American aircraft carriers, and during the period of aggravation of international tension, the cruisers of the 68bis project often accompanied the aircraft carriers of a potential enemy, keeping his ships in the zone of effective shelling. On the deck, the cruiser of this project could take more than 100 ship
barrage mines. The cruiser had a slightly increased power of steam turbine engines at full speed, more powerful artillery of auxiliary and anti-aircraft calibers, the presence of special artillery radar stations in addition to optical means of aiming guns at the target, more modern navigation and radio equipment and communications equipment, increased autonomy (up to 30 days) and cruising range (up to 9000 miles

For the first time, an all-welded hull made of low-alloy steel (instead of a riveted one) has been implemented.
Structural underwater mine-torpedo protection includes: a double bottom of the hull (length up to 154 m), a system of side compartments (for storing liquid cargo) and longitudinal bulkheads, as well as 23 main watertight autonomous hull compartments formed by transverse sealed bulkheads. In the general and local strength of the ship a significant role is played by the mixed hull recruitment system - mainly longitudinal - in the middle part, and transverse - in its bow and stern ends, as well as the inclusion of an "armored citadel" in the power circuit of the hull. The location of office and residential premises is almost identical to the Chapaev-class cruiser (project 68-k).

Characteristics, tactical and technical data and features of the project of the ship.

Basic performance data (TTX):

Displacement: 18,640 tons

Length: 210 m

Width: 23 m

Height: 52.5 m

Draft: 7.3 m

Reservations: armored belt 100 mm

Engines: Two-shaft, two turbo-gear units, type TV-7

Power: 121,000 hp With. (89 MW)

Propeller: 2

Travel speed: 35 knots (64.82 km/h)

Cruising range: 7400 miles at 16 knots

Crew: 1200 people

The ship had two masts, two chimneys, four three-gun turrets of the main caliber artillery. In the middle part of the cruiser, two blocks of superstructures are mounted. The forward superstructure accommodated: a conning tower, a forward control tower for controlling the fire of main battery artillery, two batteries of small-caliber anti-aircraft artillery. Two stern MZA batteries and a second KDP of the main caliber were installed on the aft superstructure. Six twin 100-mm universal deck-tower artillery mounts are mounted on the forecastle, three on each side. The cruiser had an all-welded hull and a double bottom. For the manufacture of structures, low-alloy steel of increased strength was used.

Fig 1. General view of the ship

To protect the vital parts of the ship, general and local armor was provided: projectile, anti-fragmentation and bulletproof. The designs used mainly homogeneous armor. The bulk of the armor fell on the citadel, consisting of a side belt and traverses covered with a protective deck. The body armor weight is about 3000 tons.

According to the calculations, it was envisaged that the armor should provide in combat conditions the protection of the vital centers of the ship from the damaging effects of 152-mm and 203-mm armor-piercing shells.

The constructive underwater protection used on the ship against the effects of enemy torpedo and mine weapons was limited only by a double bottom. The system of side compartments and longitudinal bulkheads only limited the flooded volumes inside the hull, but could not localize the impact of the explosion of the torpedo warhead.

Fig 2. Booking.

Armament.

Figure 3.152-mm three-gun turret MK-5

Twelve 152-mm B-38 guns in 4 three-gun MK-5-bis turrets were located in two groups - two turrets in the bow and stern.

The installations had their own Shtag-B radar rangefinder (2nd and 3rd towers) and an AMO-3 optical sight. The towers could be controlled both from the inside (local control) and remotely - from the central artillery post through the system remote control D 2. The surface target detection range was 120 kbt, the accurate tracking range was 100 kbt.

The Molniya ATs-68-bis fire control system was used to control the main fire.

The fire was controlled by the commander of the artillery fire control group of the main caliber division. He was at his command post - in the central artillery post.

Table1. The main characteristics of the MK-5.

Table 2. The ammunition load of the B-38 gun includes:

Universal Artillery

Gun mount SM-5-1

The protection of the ship from the light forces of a potential enemy was provided by twelve 100-mm universal guns mounted in two-gun stabilized SM-5-1 installations. The ammunition included high-explosive, high-explosive fragmentation, anti-aircraft and lighting shells (cartridges), as well as shells of passive radar interference.

Fire control was provided by the Zenit-68-bisA PUS system and a universal coordinate converter with the Yakor APLS. Radar "Anchor" was intended to control the firing of guns of universal caliber. The station had a device for automatic tracking of targets in three coordinates. The detection range of air targets was up to 30-160 kbt, surface targets - up to 150-180 kbt.

Table 3. Characteristics of the SM-5-1 gun mount

Flak

Fig 4. B-11 gun mount

The upper part of the bow superstructure of the cruiser with 30 mm AK-230 assault rifles

The air defense of the ship in the near zone was provided by 32 37-mm 70-K submachine guns, in twin V-11 gun mounts. The V-11M artillery system was put into service in 1946. The guns were mounted in a common cradle and had water cooling. Food - oboymennoe, manual. Guidance in both planes is manual. To protect the calculation from the fire of onboard weapons, the AU aircraft were equipped with a 10-mm shield covering the gun platform. The maximum firing range on the horizon was 8400 m, on air targets - 4000 m. The ammunition included fragmentation tracer and armor-piercing tracer unitary cartridges.

The installations were placed in two groups, bow and stern, consisting of 4 batteries, 2 on each side. The B-11 installations could fire at air targets at sharp bow and stern angles relative to the plane of the ship.

Table 4. Characteristics of the B-11 installation

General arrangement of courts Chainikov K.N.

§ 10. Tactical and technical (or combat) qualities of naval ships

The tactical and technical (or combat) qualities of the ships ensure the fulfillment of the tasks assigned to us, just as the operational qualities ensure compliance with the purpose of civilian ships. These qualities are:

ship's combat readiness - the ability to strike at the enemy with the aim of destroying him, while maintaining or supporting his weapons and technical means;

the survivability of a ship is its ability to withstand combat and navigational damage, the effects of fires, atomic and chemical weapons. The struggle for the survivability of a ship also means the struggle for unsinkability, putting out fires, repairing damage to the hull and combat installations, and switching over power assets and their lines.

The rest of the combat (or tactical and technical) qualities of the ships are already familiar to us: speed, maneuverability, cruising range, autonomy and habitability.