Vessel displacement coefficient. Relationships of the main dimensions. Decks and below deck set

affects propulsion, stability, unsinkability, carrying capacity, cargo capacity, but choose from the condition of reducing the resistance to the movement of the vessel (from hydromechanical considerations).

R/D

Figure 8 - Curve of the dependence of the resistance to the movement of the vessel from the coefficient of the total completeness d

At δ cr

Sharply increases the speed ® increases the power of the main engine, the mass of fuel

R ® N ® main engine power, fuel weight

But the mass of the hull is reduced, the technology is simplified, the holds are more convenient (box form)

Therefore, they try to take δ close to δ cr.

The magnitude of the drop in the speed of the vessel in waves depends on the completeness of the vessel and the size. The larger the ship, the less effect its fullness has on the magnitude of this drop in speed. Therefore, for large vessels, higher values ​​of δ can be taken.

δ = a – b* Fr

where a and b are numerical coefficients depending on the type of ship.

Table 10 Calculation formulas for determining δ

The coefficient of completeness of the area of ​​the midship frame already fixed if selected δ and j. However, when choosing it, the following circumstances must be borne in mind.

For relatively slow and medium speed vessels(Fr<0,30)b take as much as possible to sharpen the ends of full ships (reduce drag). Upper limit ( b=1) is limited by the possibility of constructing a theoretical drawing without noticeable breaks in the waterline at the boundaries of the cylindrical insert.

For determining b the following expressions can be used:

At δ <0,650 b =0,813 + 0,267 δ ;

At 0.615< δ <0,800 b =0,928 + 0,080 δ ;

At δ > 0,800 b =0,992.

For less complete relatively fast ships, for which there is no reason for a special sharpening of the extremities, the following values ​​\u200b\u200bare recommended b :

Table 11 Values b for relatively fast ships (Fr > 0,30)

The coefficient of completeness of the area of ​​the constructive waterline(DWL) affects mainly the stability, unsinkability and cargo capacity of ships. At the same time, it is geometrically related to the shape of the frames, taper angles of the waterline and coefficients δ and j. Therefore, initially it is taken depending on these coefficients, then refined during the development of a theoretical drawing.

For vessels with U-frames and V-frames, the following ratios may be used:

a = δ + 0.10 and a = δ = 0.12, respectively.

Assortment completeness ratio

Completeness of the assortment - the ability of a set of goods of a homogeneous group to satisfy the same needs. A relative indicator of the completeness of the range is the coefficient of completeness, which is calculated on a single basis of the selected product /14, p.57/.

The power of the electric motor was chosen as a fundamental feature in calculating the completeness factor.

When calculating the completeness ratio of the assortment, based on the power of the electric motor, it is necessary to determine the actual completeness and the basic completeness. As a result of the research conducted at three outlets, it turned out that each seller can provide the consumer with an electric drill with the following motor power (W): 400, 450, 500, 550, 600, 650, 700, 850, 900, 1000, i.e. the fullness is 10. In addition, the main competitors of the studied outlet were found to have electric drills with electric motor powers of 800W and 950W. Based on the above data, it follows that the base completeness is 12.

To determine the completeness coefficient, the formula is used:

Kp = (Pd: Pb), (2)

where Kp - coefficient of completeness;

Pb - completeness basic;

Pd - real fullness,

Let's calculate the indicator of the completeness of trouser suits:

Kp \u003d (10:12) \u003d 0.83

As a result of calculations, the completeness factor of electric drills was 0.83. This coefficient shows that the range of electric drills with different motor power in the outlet under study is presented quite fully, in comparison with the available number of electric drills with the same motor power from the main competitors. Since this figure is quite high, it means that there is a high probability that consumer demand for electric drills is satisfied.

Assortment novelty ratio

The novelty (updating) of the assortment is the ability of a set of goods to satisfy changing needs through new goods /7, p.14/. The reasons for updating the assortment are:

Replacement of goods that are morally obsolete, not in demand;

Development of new products of improved quality;

Creation of competitive advantages of the organization;

Meeting the needs of a wide range of consumers.

Consumers of new products are "innovators". New products satisfy not so much the physiological as the psychological and social needs of such a group of people.

The novelty of the assortment is characterized by the coefficient of novelty, which is defined as the ratio of the number of new products in the general list of presented (H) to the actual breadth of the assortment (Wd).

Thus, the novelty coefficient is calculated by the following formula:

Kn \u003d (N: Shd), (3)

where Kn is the coefficient of novelty;

H - the number of new models of electric drills that went on sale for a certain period of time;

Shd - the actual breadth of the range.

This indicator is necessarily calculated for a certain period of time and shows the number of new products that went on sale to the department for the selected period of time.

By interviewing the seller of the studied store "Amursnabsbyt", it was found that over the past 3 months, 10 new models of electric drills have appeared.

Let's calculate the novelty coefficient:

Kn=(10:43)=0.23

The novelty coefficient for this outlet was 0.23. This fact indicates a gradual renewal of the range of electric drills. The Amursnabsbyt store pays great attention to updating its own assortment, offering new models in moderation, minimizing the risk of incurring losses due to low demand for the presented new models of electric drills.

The main, or main, geometric dimensions of the vessel are the length L, the width B, the depth H, the freeboard F, the draft T and the overall height of the vessel with superstructures h, (Figure 5). The ratio of these dimensions characterizes the shape of the vessel and its main qualities.

Figure 5 - Theoretical and overall dimensions of the vessel

There are the following main dimensions:

a) theoretical (calculated), measured according to the theoretical drawing without taking into account the thickness of the outer skin of the hull;

b) practical (constructive), measured taking into account the thickness of the skin;

c) overall (largest), measured between the extreme non-removable protruding parts of the ship.

The length of the vessel L is measured in DP between perpendiculars along the GVL, and in the presence of a cruising stern - between the bow and stern perpendiculars drawn along the axis of rotation of the rudder. Distinguish the greatest length of the vessel L max as the greatest distance in the diametrical plane. Vessel's breadth B is measured at the load waterline at its widest point. Overall width B max is measured in the midship plane between fixed parts (including fenders).

The ship's draft T is measured in the midship plane as the distance from the main plane to the load waterline. If the ship is trimmed, then the draft T cf is measured as half the sum of the draft in the bow T N and in the stern T K

The draft in the bow T N and in the stern T k, in turn, is measured from both sides of the vessel and calculated from the dependencies

Draft maximum T max. there is an overall dimension along the perpendicular from the GVL to the protruding outer edges of the bottom plating or the protruding parts of the rudder, propulsion unit or their guards.

The depth H is the vertical distance from the main plane to the top line of the side, measured in the midship plane. The freeboard height F is the distance from the GVL to the upper line of the side in the midship plane. The ship's height h is the overall dimension from the GVL to the highest point of the ship. This size must be known when passing ships under bridges. To characterize the shape of the vessel and some of its qualities, the ratios of the dimensions of the vessel listed above to each other are of great importance.

The L/B ratio affects the propulsion of the vessel. The larger it is, the sharper the ship, the less resistance to movement. Most often, this ratio is in the range of 48.

The ratio L / H affects the strength of the vessel. The larger it is, the more weight of additional materials is needed to provide the desired strength of the vessel. For tugboats this ratio is within 812, for cargo ships it reaches 50.

The H/H ratio affects the ship's stability. With its increase, the initial stability increases.

The W/T ratio affects stability, propulsion and course stability. The more W / T, the more stable the ship; for tugboats V/T = 2 4, for cargo ships up to 12.

The L/T ratio affects the agility of the vessel; the smaller it is, the more maneuverable the vessel is (excluding jet-propelled vessels, where agility is ensured by ejection of water through special side nozzles).

The H/T ratio affects the stability, strength and capacity of the vessel. For motorboats, it ranges from 1.2 to 3.6; for cargo ships - from 1.05 to 1.6.

For a better knowledge of the forms of the vessel, dimensionless coefficients of completeness are also used, obtained from a comparison of the areas and volumes characteristic of the vessel with the correct simplest geometric areas and volumes. The coefficients of completeness are used at the initial stage of design, as well as in solving many practical issues for a quick and approximate determination of some of the main elements of the ship. To obtain these coefficients, it is customary to designate the GVL area through S (it characterizes the completeness of the ship's contours in terms of - in a horizontal section); midship area through and (it characterizes the completeness of the ship's contours in cross section); the area of ​​the diameter through A (it characterizes the completeness of the contours of the vessel in the longitudinal section); the volume of the underwater part of the ship through V, which is a volumetric displacement characterizing the overall completeness of the ship's contours.

The ratios of the named areas and volumes to the areas and volumes of geometrically correct figures with the same overall dimensions are called the coefficients of completeness of the underwater part of the vessel.

GVL completeness coefficient b is the ratio of the area of ​​the load waterline S to the area of ​​a rectangle with sides L and B, i.e.

navigation vessel buoyancy cargo capacity

Its values ​​for river cargo ships range from 0.84 to 0.9.

The midsection fullness coefficient in is the ratio of the area of ​​the midship frame and to the area of ​​a rectangle with sides B and T, i.e.

Its values ​​for river cargo ships are 0.96? 0.99.

The coefficient of completeness of the diameter r is the ratio of the area of ​​the diameter A to the area of ​​a rectangle with sides L and T, i.e.

This coefficient is rarely encountered in settlement practice.

The coefficient of completeness of volumetric displacement d is the ratio of the volume of the vessel V to the volume of a parallelepiped with sides L, B and T, i.e.

Its values ​​fluctuate within 0.85? 0.90.

The coefficient of longitudinal completeness of displacement q is the ratio of the volumetric displacement of the vessel V to the volume of a prism with a base equal to the midship area and height L, i.e.

The coefficient of vertical fullness of displacement h is the ratio of volumetric displacement V to the volume of a prism with a base equal to the area of ​​the load waterline S and height T, i.e.

The coefficient of lateral fullness of displacement w is the ratio of the volumetric displacement of the vessel V to the volume of a prism with a base equal to the area of ​​diameter A and height B, i.e.

This coefficient is almost never found in calculation practice.

Thus, the coefficients of completeness b, c, d and e are the main ones, and c, h and w are derivatives.

LECTURE №2

The geometry of the ship's hull. Main dimensions. Completeness coefficients. Classification of ships. The role and tasks of classification societies.

The bounding surfaces and planes of sections of the ship's hull, as well as volumes, are almost impossible to describe with mathematical functions. Therefore, to depict the shape of the body, it is cut by a system of planes (Fig. 1, 2).

Fig.1 - The system of planes of the ship's hull

The geometric shape of the outer surface of the ship's hull is depicted in the form of a theoretical drawing (Fig. 3).

The following are taken as the projection planes of the theoretical drawing:

The main plane (OP) passing through the middle straight section of the keel line

Diametral (vertical-longitudinal), passing along the entire vessel and conditionally dividing it into two symmetrical parts - the starboard and port side. The projection of the ship on this plane - side.

The plane of the cargo (GVL) or structural (DWL) waterline, coinciding with the surface of calm water when the ship is sailing along the design draft. The projection of the ship on this plane - half-latitude.

The plane of the midship frame (vertically transverse), passing in the middle of the estimated length of the vessel and dividing it into two asymmetrical parts - bow and stern. The projection of the ship on this plane - frame.

Fig.2 - Image of the ship's hull on the theoretical drawing:

a - side, b - frame, With - half-width, 1 - bow body, 2 - diametral plane, 3 - aft body

Sections of the vessel with planes parallel to the planes of projections form three systems of main sections: frames, waterlines and buttocks.

Fig.3 - Theoretical drawing of the ship's hull

Theoretical drawing- the basis of all shipbuilding drawings, for example, the position and contour of structural frames (plaza drawing), sheet developments, as well as theoretical ship calculations (for example, stability and trim calculations).

The main geometric dimensions of the vessel is its length L, width B, board height H and draft T(see Fig.4).

Overall length
- the distance measured in the horizontal plane between the extreme points of the fore and aft ends of the hull without protruding parts.

Design waterline length
- the distance measured in the plane of the design waterline between the points of intersection of its bow and stern parts with the centreline.

Length between perpendiculars
- the distance measured in the plane of the design waterline between the bow and stern perpendiculars.

Fig. 4 - The main geometric dimensions of the vessel

Length at any waterline measured as
.

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

Width
- the distance measured between the extreme points of the body, excluding protruding parts.

Width at midship frame AT- the distance measured on the midship frame between the theoretical surfaces of the sides at the level of the design or design waterline.

Board 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 main deck
- the depth of the side to the uppermost solid deck.

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

Draft fore and aft and - are measured on the bow and stern perpendiculars to any waterline.

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

Bow and stern sheer h n and h to- smooth rise of the deck from the midships to the bow and stern; the magnitude of the rise is measured on the bow and stern perpendiculars.

Beams die 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- distance measured vertically at the side at the middle of the ship's length from the upper edge of the deck line to the upper edge of the corresponding load line.

The shape of the vessel is to a certain extent characterized by the following coefficients of completeness and ratios of the main dimensions (see Fig. 5):

Fig.5 - Determination of the coefficients of completeness of the ship's hull

The coefficient of the total displacement of the displacement - volume ratio of the underwater part of the hull to the volume of a rectangular parallelepiped with the dimensions of the ribs , , , into which this volume fits (Fig. 5, a):

.

Waterline area completeness factor
- the ratio of the area of ​​the constructive (cargo) waterline to the area of ​​a rectangle circumscribed around it with sides and (Fig.5, b):

,

The coefficient of completeness of the area of ​​the midship frame - the ratio of the submerged part of the midship frame area
to the area of ​​a rectangle circumscribed around it with sides and (Fig.5, c):

,

Vertical completeness factor corps - the ratio of the volume of the underwater part of the hull to the volume of a straight cylinder with a base bounded by the contour of the design waterline and a generatrix equal to the ship's draft :

.

Longitudinal completeness coefficient - the ratio of the volume of the underwater part of the hull to the volume of the cylinder, the base of which is outlined by the midship frame, and the length of the generators is equal to the length of the vessel :

.

The main ratios of the main dimensions are
,
,
,
,
, as well as their inverse relations.

The increasing flow of goods transported by sea, the desire to reduce transport costs and to maximize the loading of available ports, the variety of goods transported, the development of shipbuilding technology, as well as the increasingly popular tourism - all this has led to the fact that the traditional, which operated half a century ago the division of ships into passenger and cargo is no longer accepted.

Vessels are classified: by ACT, by area of ​​navigation, by type of propeller and engine, by nature of movement, and, finally, by purpose. According to the ACT, full-set and shelter-deck ships are distinguished (Fig. 6).

Complete ships have a deck that runs from stern to bow, which simultaneously serves as a freeboard deck and a bulkhead deck, since transverse watertight bulkheads are brought to it (Fig. 6, a). Varieties of full-set ships: three-island, well and well with a quarterdeck. The three-island vessel (Fig. 6, b) has three superstructures: in the stern (poop), in the middle of the vessel (middle superstructure) and in the bow (tank). This type of ship was common between the two world wars. Sometimes the stern and middle superstructures were combined into a continuous stern superstructure. At the same time, a so-called well was formed between the aft superstructure and the tank. Hence the name "well vessel" (Fig. 6, c). The volume of holds is limited in the stern by the propeller shaft tunnel and the shape of the aft end. To compensate, the main deck in this place was sometimes raised (Fig. 6, d), usually by half a tween deck, and the so-called quarter deck arose.

a - full ship 1 - upper deck and bulkhead deck; 2 - buoyancy margin; 3 - bulkheads; 4 - tween deck

b - three island ship 1 - yut; 2 - middle superstructure; 3 - tank; 4 - main (upper deck)

With - well boat 1 - upper deck; 2 - elongated poop; 3 - well; 4 - tank

d - well boat with quarterdeck 1 - quarterdeck; 2 - upper deck; 3 - middle superstructure; 4 - well; 5 - tank

e – shelteredvessel 1 - main deck and shelter deck; 2 - measuring hatch; 3 - freeboard deck (bulkhead deck); 4 - bulkheads

Fig.6 - Architectural and structural types of ships

For full-set ships and their varieties, the buoyancy margin is determined by the volume of the ship's hull between the waterline at maximum draft and the bulkhead deck. In the figure, the shaded area corresponds to the reserve buoyancy of full-size vessels. Shelter deck vessels (Fig. 6, f) have a significantly lower margin of buoyancy than full-set ones. The upper deck of shelter deck ships serves simultaneously as the main deck, and the bulkhead deck (freeboard deck) is located below. There are superstructures on the upper deck, but they are not taken into account when measuring the vessel, since they are not impenetrable and solid. These add-ons are shown in the figure by dark rectangles.

By sailing area Distinguish between ships of unlimited navigation, which are sometimes also called ships of long-distance navigation or seagoing ships, and ships of limited navigation (ships of coastal navigation, ships for navigation in sea bays, etc.

Type of main engine distinguish ships with a steam engine (with a reciprocating steam engine and a steam turbine); ships with an internal combustion engine (with an internal combustion engine and with a gas turbine); ships with nuclear power. This division of ships by engine type is quite rough.

By type of propulsion ships with a mechanical drive are distinguished: ships with paddle wheels (nowadays almost never occur; ships with a propeller (fixed-pitch screw and variable-pitch screw), which can also be located in the nozzle; ships with a special propulsion (vane and jet).

Other, less important principles for the classification of ships are by type of material used(ships made of wood, light alloys, plastics, reinforced concrete) and by number of buildings(single-hull, double-hull - catamarans and three-hull - trimarans).

With the development of shipbuilding, the classification of ships is becoming more and more relevant. on the principle of movement on water. There are displacement ships (the vast majority of sea-going ships belong to them) and ships that are supported when moving by dynamic force (hydrofoils and hovercraft).

From the point of view of operation, the most important is the division of ships according to their purpose, since the specialization of ships has been rapidly developing recently.

By appointment distinguish between passenger ships, including: linear passenger liners, cruise and coastal passenger ships (for excursions and cruises) and cargo ships, including universal ones for general cargo, container ships, ro-ro ships (ships with horizontal cargo handling), barge carriers, for transportation bulk cargo, tankers, refrigerated and other vessels for the transport of special cargo (for example, for the transport of timber, machinery, extra heavy cargo, etc.).

Cargo ships can also be subdivided according to the type of their operation: into line ships that run between ports on a schedule, and irregular ships (tramps), which go depending on the accumulation of a consignment.

We should also mention fishing vessels (fishing research, fishing, processing vessels-factories and transport vessels for fish and fish products), as well as special and auxiliary vessels (for hydrographic and oceanological research, cable, tugs, icebreakers, fire, rescue, etc.).

maritime shipping- transportation of people and goods by sea has long been associated with a certain risk. The ship was not always able to withstand the elements of the sea. And in our time, not only damage occurs, but also the death of ships due to unsatisfactory strength, stability, reliability of equipment and equipment of the vessel, improper placement of cargo, errors in navigation, as well as due to fires, collisions and groundings. Therefore, improving the navigation safety of ships has always been a serious task. In the 18th century, the first national classification societies arose, which divided the seagoing ships of that time - sailing - into the appropriate classes, depending on their seaworthiness. After the sinking of the passenger liner Titanic, which competed in the Blue Ribbon race, in 1912, a number of international conferences on ship safety were held and relevant conventions were adopted.

After the Second World War, the Intergovernmental Maritime Consultative Organization (IMCO) was formed within the framework of the UN, the competence of which includes international cooperation on security issues in the field of shipbuilding and shipping. The International Convention for the Safety of Life at Sea of ​​1960 and the new International Load Lines Agreement of 1966 are recognized by almost all governments of shipping states and are reflected in legal bulletins, regulations, etc. Along with this, there are other national regulations that relate to the safety of navigation and ships. Compliance with the rules for the construction of ships, which are contained in the above contracts and agreements, is controlled by national classification or other state bodies.

Since the safety of a ship depends mainly on its strength, stability, reliability of equipment and equipment, insurance companies, when concluding a contract, determine the characteristics and condition of the ship. In order not to be mistaken, insurance companies in the past kept their own experts in the service, who were supposed to judge the technical condition of the ships. The associations of experts that arose later divided all the ships into classes depending on their seaworthiness and assigned a certain sign to each class. The first printed list, in which the characteristics of ships were indicated by certain characters, appeared in 1764 in England - it was published by Lloyd's Register. This classification society arose in 1760 and, along with the French Bureau Veritas, founded in 1828, is the oldest. All countries with developed shipping have their own national classification organizations, which, based on the experience of building and operating ships, issue the Rules for their classification, construction and safety of ships.

Main goals classification societies:

Development and publication of the Rules;

Checking the classification documentation (drawings) on new and converted ships;

Acceptance of ships at shipyards and supervision of the construction of new ships, as well as the repair and re-equipment of old ones;

Classification and classification (revision) inspections of ships in service;

Registration of ships in the Ship Register.

The publication of the Rules is necessary in order to inform shipping companies, design offices and shipyards about the conditions of classification. They contain requirements for materials, dimensions and conditions for the manufacture of ship hull parts, rules for the installation of mechanical and electrical installations, technology for performing welding and riveting, rules for equipment and fittings, ensuring the necessary stability and protection against fires. In addition, Rules are issued for special types of ships and installations (tankers, ore carriers and bulk carriers, yachts, hold refrigeration units, etc.). There are Rules that relate to the safety of operation and movement of ships, such as Rules for ensuring unsinkability, Rules for the maintenance of radio, television and navigation installations, Regulations or recommendations for the placement of goods - grain, ores, etc. The scope of the rules published by the classification organizations, depends on the tasks assigned to them and the rights given to them.

When supervising the construction at the shipyard and classifying ships, the classification authorities proceed from the relevant documentation. The documents (drawings, calculations, descriptions) must contain all the data necessary to assess the strength and reliability of the ship as a whole or individual installations and parts of equipment. The construction of new and converted old ships can be carried out only after the approval of all the necessary documentation for this.

When classifying a ship, it is assumed that its hull, installations, equipment and arrangements must comply with legally binding requirements. The class is assigned to a vessel for several years if it is in satisfactory condition. Regular classification inspections - revisions are carried out on the vessel. Typically ships are inspected once a year afloat to confirm class and every 3-5 years in dock to renew class. There are deviations from this rule: ships with more wear and tear and old ones that no longer have the highest class are inspected at shorter intervals. Passenger ships once a year, and cargo and other seagoing ships, once between two class renewal inspections, are subject to a bottom inspection in the dock. Along with these regular inspections, special inspections are also carried out after an accident, fire or other damage to the ship.

Vessel classification is confirmed:

By assigning a class to it;

Drawing up a ship class certificate (certificate) and other documents, as well as transferring them to the owner of the ship (ship owner, captain).

The list of ships to which the Register class has been assigned is published annually by classification societies.

With the increase in the intensity of shipping, the number of maritime disasters has also increased, as a result of which people and great material values ​​\u200b\u200bare killed. The reasons for many accidents include the unsatisfactory condition of safety devices, insufficient strength and defective equipment of ships, as well as poor professional training of crew members. Therefore, the maritime countries have agreed on the minimum requirements that should be placed on ships with regard to their safety. The first agreement of 1914 was replaced in 1929 by the London Convention for the Safety of Life at Sea (SOLAS 1929), which in 1948 and 1960 reprinted. New changes were developed by a conference held in 1972. SOLAS contains requirements that are mandatory for all ships (with the exception of military ones) of the States parties to the treaty.

These requirements mainly concern:

Current inspections and inspections of ships, including machinery, devices and equipment, as well as the preparation of safety certificates;

Ship structures in relation to the separation of the hull of passenger ships by bulkheads and the stability of damaged ships;

Execution and installation of bulkheads of peaks and engine room, propeller shaft tunnel, double bottom;

Closing of openings in watertight bulkheads and in outer plating below the maximum draft;

Drainage systems on passenger ships;

Stability documentation for passenger and cargo ships, as well as water ingress safety plans for machinery and electrical installations;

Fire protection, detection and extinguishing of fires on passenger and cargo ships, as well as general fire fighting activities;

Equipment of passenger and cargo ships with life-saving appliances;

Equipping ships with telegraph and radiotelephone installations.

The main dimensions of the vessel include: length (L), width (B), depth (H or D), draft (T or d)

Vessel length (L). Distinguish length:

According to the constructive overhead line /Lkvl / - the distance (in the plane of the waterline) between the points of its intersection with the stem and stern;

Between perpendiculars (Lpp) - the distance in the square of the waterline between the bow and stern perpendiculars; the bow perpendicular passes through the extreme bow point of the waterline, the stern perpendicular passes through the axis of the rudder stock;

The greatest / Lnb / - the distance between the extreme points of the bow and stern ends;

Overall / LGB / - the greatest length plus protruding parts.

Vessel width B. There are widths:

By DWL /VKVL/ - distance in DWL area in the widest part of the hull between the points of its intersection with the inner surface of the hull plating;

On the midsection /Vmd/ - the same as Vkvl, but in the plane of the midship frame;

The largest /Vnb/ - the distance in the widest part of the body between its extreme points, excluding protruding parts

Dimensional /Vgb/ - Vnb, taking into account the protruding parts.

Vessel's draft /d, T/ - distance in the plane of the midship frame between the main square. (OP) and KVL at the estimated overhead line.

Vessel's landing - average draft, trim (difference between bow-catfish and stern draft), roll (roll angle). Control over the landing of the vessel during operation is carried out according to the marks of the recess, which are applied in Arabic numerals on both sides on the stem, in the area of ​​​​the midship, stern at a distance of 10 cm from each other (in decimeters).

Board height /D,Н/ - vertical distance in the midship plane at the side from the inner edge of the vertical keel to the upper edge of the upper deck beam.

Freeboard F = D - d or H - T

Relationships of the main dimensions(L/B, W/T, H/T, L/H, W/H serve as the primary characteristic of the shape of the hull of the vessel, and they also affect the seaworthiness of the vessel.
COMPLETENESS COEFFICIENTS of the underwater part of the ship's hull also serve as a characteristic of the shape of the hull and, moreover, for approximate calculations of the main dimensions of the ship.

S / LB - coefficient of completeness of the KVL area

\u003d / BT - coefficient of completeness of the midship frame area

V/ LBT - coefficient of overall completeness

V/ L - coefficient of longitudinal completeness

V/ST - coefficient of vertical completeness

The table of ratios of the main dimensions and coefficients of completeness is given in F on page 62 of Table 6