Negative Difference. The concept of the longitudinal stability of the vessel

Bank and trim can be formed as a result of moving people, cargo, with swingturns. The occurrence of the chassis differential small vessels The nose or stern arises as a result of the wrong position (angle of inclination) of the suspension motor on the trunk of the vessel. Roll and differential angles can reach dangerously critical, especially if there is water vessel and overflow. The transfusion of water towards the slightest lifting of the vessel contributes to the formation of an even more roll or a differential and can cause the vessel tilting. There should be no water in the body.

When driving, the resistance from the side of the tailing side is more and the ship seeks to appreciate in the opposite direction, that is, smaller resistance. Therefore, to keep the vessel on the course, it is necessary to shift the steering wheel in the direction of the tail, which increases the power of the resistance and, accordingly reduces the speed.

With sharp turns of the displacement vessels, the roll is especially great and sent to the outer side. People on board, with a sudden maneuver, can move towards the roll and thereby aggravate the position of the vessel. There may be a real risk of tipping. The vessel needs to know the dependence of the speed of its vessel and the maximum possible, in terms of safety, the wheelchair angle of the steering wheel. Before maneuvering, make sure that people are in their places, and there are no prerequisites for moving them and cargo.

Glissing vessels, by virtue of the shape of the building of the case, are plugged into the inner side of the turn. This is more safe because the inertia force is directed in the opposite side of the turn and seeks to reduce the roll. It should be remembered that people in the cockpit, especially standing, can fall or fall out overboard. It is necessary to avoid sharp turns, and if necessary, be sure to warn people on board.

For a small displacement vessel, a differential is considered a differential to feed no more than 5 cm or the "smooth keel" position. With a differential to feed, the speed is greater than 5 cm, t. C. Significant immersion of the feed increases the fascinable mass of water and the windshield resistance of the vessel. The feeder on the feed causes increased stability of the vessel in the course. If necessary, change the direction of movement, it poorly reacts to the steering wheel, it is prone to the wind.

With a differential on the nose, the water resistance also increases and speed decreases. The trim on the nose worsens the stability of the vessel in the course and causes an increased sensitivity to the handling of the steering wheel. At the slightest blackwave, the vessel begins to deviate from the rectilinear course and becomes difficult to control the path in rectilinear areas. These phenomena are explained by the fact that in the presence of a differential, the hydrodynamic effect on the vessel body by its length is significantly different from the usual operating conditions.

With a differential of the nose of the feed of the vessel, having a smaller resistance of the surrounding water, becomes more mobile and overly sensitive to the wheelchair, and with a differential on the stern - on the contrary.

In glissing vessels, the sofa focus makes it difficult to go to gliding. The vessel may not overcome the "hump" of resistance. When gliding, the phenomenon of "delphinning" is possible, periodic vertical movement of the nose.

This phenomenon is easy to stop, shifting part of the cargo in the nose. In case of difficulty, the exit to the glyceing of the vessel with overloaded feed is quite even temporary movement of the part of the cargo in the nose. With a differential on the nose of the glissing vessel, the stem is almost not rising above the water. This increases the moistened surface of the vessel, therefore, the speed decreases. In addition, the course at an angle to the wave is possible a sharp burrowing of the vessel. This happens as a result of the fact that if from the left side at the entrance to the wave there will be a majority of the wave, the ship goes to the right and vice versa.

It should be remembered that when towing a towed vessel, you will not allow a differential to the sovereign. In this case, the ship will constantly burn, and at the time of his return to the initial course it is possible to overturn. At the same time, the differential to the stern gives the opportunity to go strictly in the Kilwater towing.

Ship Difference (from Lat. Differens, Differentis Parental Padge - Difference)

the slope of the vessel in the longitudinal plane. D. s. It characterizes the landing of the vessel and is measured by the difference in its precipitate (deepening) with feed and nose. If the difference is zero, they say that the ship "sits on a smooth keel", with a positive difference - the vessel sits with a differential to feed, with a negative - with a differential on the nose. D. s. affects the valid of the vessel, the conditions of the propeller, the permeability in the ice, etc. D. s. It happens static and chassis that occurs at high speeds of movement. D. s. Typically adjust the reception or removal of water ballast a.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

Watch what is a "Ship Difference" in other dictionaries:

Ship Difference - Origin: from Lat. Differens, Differentis Difference the slope of the vessel in the longitudinal plane (around the transverse axis passing through the center of gravity of the area of \u200b\u200bwaterline) ... Sea Encyclopedic Directory

- (Trim difference) The angle of the longitudinal inclination of the vessel, which causes the difference in the precipitation of the nose and the stern. If the deepening of the nose and the stern is equally, the vessel sits on a smooth keel. If the deepening of the feed (nose) is greater than the nose (feed), the vessel has ... ... ...

- (Lat., From Differe to distinguish). The difference in the depth of immersion in the water of the stern and the nose of the ship. A dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. Differ Lat., From Differre, raise. The difference in dive into water feed ... ... Dictionary of foreign words of the Russian language

- (vessel) the slope of the ship in the longitudinal vertical plane relative to the sea surface. It is measured by the differenttometers in degrees for a submarine or the difference between the deepening of the feed and the nose for surface ships. Affects turning ... ... marine dictionary

- (from Lat. Differens Difference) Difference in the sediment (deepening) vessel nose and feed ... Big Encyclopedic Dictionary

Sea term, the angle of deviation of the vessel housing from the horizontal position in the longitudinal direction, the difference in the sediment of the stern and the nose of the vessel. In aviation to designate the same angle defining the orientation of the aircraft, the term is used ... ... Wikipedia

BUT; m. [Lat. Differens] 1. Spec. The difference in the sediment of the nose and the stern of the vessel. 2. Finance. The difference in price for goods when ordering and receiving it in the process of trading operations. * * * Different (from lat. differens difference), difference in sediment (deepening) vessel ... ... encyclopedic Dictionary

Trim - Differ, the difference in depth (landing) of the vessel nose and firing; If, for example, feed is in-depth on 1 ft. More nose, then they say: the ship is D. on the feed of 1 ft. D. I had a special value in a sail. Fleet, GDѣ good sailboat d. Imitation D. on ... ... Military encyclopedia

- [from lat. Differens (Differentia) Difference] vessel tilting the vessel in the longitudinal plane. D. Defines the landing of the vessel and is measured by the difference between the sediments of the stern and the nose. If the difference is zero, they say that the vessel is sitting on a smooth keel; If the difference ... Big Encyclopedic Polytechnic Dictionary

Ship Difference (Ship) - The slope of the ship (vessel) in the longitudinal plane. It is measured with the help of a device of a differenttometer as the difference in the precipitate of Io SA and feed in meters (for pl in degrees). It occurs when flooding the premises or compartments in the tip of the ship, uneven ... ... Dictionary of Military Terms

The stability that manifests itself with the longitudinal inclinations of the vessel, i.e., when differentiated, is called longitudinal.

Fig. one

Despite the fact that the drive corners of the vessel rarely reach 10 degrees., And usually 2 - 3 degrees, longitudinal inclination leads to significant linear differentials with a large length of the vessel. Thus, the vessel with a length of 150 m The angle of inclination 1 0 corresponds to a linear differential equal to 2.67 m. In this regard, in the practice of operating vessels, issues related to the differential are more important than the issues of longitudinal stability, since transport vessels with normal ratios Longitudinal stability is always positive.

Under the longitudinal inclination of the vessel to the angle ψ around the transverse axis of C.V. It moves from the point C to the C1 point and the power of maintenance, the direction of which is normal to the active waterline, will act at an angle to the initial direction. The line of action of the initial and new direction of maintenance forces intersect at the point. Point of intersection of the line of operation of maintenance forces with infinitely small inclination in the longitudinal plane is called the longitudinal meticenter M.

Radius of curvature of the movement curve C.V. In the longitudinal plane is called a longitudinal meticenter radius R, which is determined by the distance from the longitudinal meticenter to the TsV.

The formula for calculating the longitudinal metuclear radius R is similar to the transverse metuclear radius: R \u003d i f / v, where i f - the moment of inertia of the area of \u200b\u200bwaterline relative to the transverse axis passing through its ts.t. (point f); V is a volumetric displacement of the vessel.

The longitudinal moment of the inertia of the IF waterline area is much larger than the transverse moment of inertia I x. Therefore, the longitudinal metuclear radius R is always significantly larger than the transverse R. Approximately believe that the longitudinal metuclear radius R is approximately equal to the length of the vessel.

The main position of stability is that the regenerating moment is the moment of a pair formed by the power of the vessel's weight and power of maintaining. As can be seen from the drawing as a result of an application of an appearance of an external moment, called the differential moment MDIF, the vessel obtained an inclination to the small angle of the differential ψ. Simultaneously with the advent of the angle of the differential, the regenerating moment of Mψ, acting to the side opposite the action of the differential moment.

The longitudinal inclination of the vessel will continue until the algebraic sum of both moments becomes zero. Since both points act in opposite parties, the equilibrium condition can be written in the form of equality:

M D and F \u003d M ψ

The regenerating moment in this case will be:

M ψ \u003d d '· g k 1 (1)

• where GK1 is the shoulder of this moment, called the shoulder of the longitudinal stability.

From the rectangular triangle G M k1 we get:

G k 1 \u003d m g · sin ψ \u003d h sin ψ (2)

Included in the last expression The value of Mg \u003d H determines the elevation of the longitudinal meticenter over the ts. The vessel is called longitudinal meticenter height. Substitting the expression (2) in formula (1), we get:

M ψ \u003d d '· h · sin ψ (3)

Where the product d'h is the coefficient of longitudinal stability. Having in mind that the longitudinal meticenter height H \u003d R - A, formula (3) can be written in the form:

M ψ \u003d d '· (r - a) · sin ψ (4)

• where a is the elevation of the Ts.T. Ship over his Ts.V.

Formulas (3), (4) are metuclear longitudinal stability formulas. In view of the smallness of the angle of the differential in the indicated formulas, instead of sinψ, you can substitute an angle ψ (in radians) and then:

M ψ \u003d d '· h · ψ and l and m ψ \u003d d' · (r - a) · ψ.

Since the magnitude of the longitudinal metuclear radius R is many times more transverse R, the longitudinal meticenter height n of any vessel is many times more transverse H, so if the ship has transverse stability, the longitudinal stability is provided with obviously.

Different vessel and differential angle

In the practice of calculating the lines of the vessel in the longitudinal plane associated with the definition of the differentiation, instead of the angular differential, it is customary to use a linear differential, the value of which is defined as the difference in the vessel's precipitate with the nose and feed, that is, d \u003d t h - t.

Fig. 2.

The differential is considered positive if the sediment of the vessel's nose is greater than feed; The stern is considered negative. In most cases, trips are floating with a differential to feed. Suppose that the vessel floating on a smooth keel on the Waterlinnia should, under the action of some point, a differential received a differential and its new operating waterline occupied a position in 1 l 1. From the formula for the restoring point we have:

Ψ \u003d m ψ d '· h

We carry out the dotted line of AB, parallel VL, through the intersection point of the stern perpendicular with 1 l 1. DIFERENT D - determined by the ABE triangle cathet. From here:

t g ψ \u003d ψ \u003d d / l

Compare the last two expressions, we get:

d L \u003d M ψ D '· H, O T C Y D A M ψ \u003d D L · D' · H

Changing the differential in the longitudinal movement of cargo

Consider the methods of determining the sediment of the vessel under the action of a differential torque resulting from the movement of the cargo in the longitudinal horizontal direction.

Fig. 3.

Suppose that the weight of p is moved along the vessel to the distance ιx. Moving the cargo, as already indicated, can be replaced by an application to the vessel of the moment of the pair of forces. In our case, this moment will be different and equal: M diff \u003d p · l x · cosψ. The equilibrium equation during the longitudinal movement of cargo (the equality of the differential and restoring moments) has the form:

P · l x · cos ψ \u003d d '· h · sin

• location:

t g ψ \u003d p · i x d '· h

Since the small incidence of the vessel occurs around the axis passing through the C.T. Waterlinnia Square (T.F), you can get the following expressions to change the sediment with the nose and feed:

Δ t h \u003d (l 2 - x f) · t g ψ \u003d p · i x d '· h · (l 2 - x f)

Δ t h \u003d (l 2 + x f) · t g ψ \u003d - p · i x d '· h · (l 2 + x f)

Therefore, precipitation nose and feed when moving the cargo along the vessel will be:

T n \u003d t + δ t n \u003d t + p · i x d '· h · (l 2 - x f)

T K \u003d T + Δ T K \u003d T + P · I x D '· H · (L 2 - x F)

If we take into account that Tg ψ \u003d d / l and that D '· h · sin ψ \u003d mψ, you can write:

T H \u003d T + P · I x 100 · m 1 s m · (1 2 - x F L)

T K \u003d T - P · I x 100 · m 1 s m · (1 2 + x F L)

• where T is the sediment of the vessel when the position on the smooth keel;
• M 1cm - moment, differential vessel for 1 cm.

The value of the abscissa X f is found according to the "curves of the theoretical drawing", and it is necessary to strictly take into account the sign before x F: when the point F is located in the nose of the Middle, the value x F is considered positive, and when the point is arranged in the stern from the Middle - negative.

L x shoulder is also considered positive if the load is transferred towards the nasal part of the vessel; When transferring the cargo to the stern of the shoulder L x is considered negative.

Options precipitation scale due to reception 100 tons of cargo

The largest distribution was obtained by the scale and tables of changes in the sediment with the nose and feed from the reception of a single cargo, the mass of which, depending on the displacement, is selected equal to 10, 25, 50, 100, 1000 tons. The basis of building such scales and tables is the following considerations. The change in the sediment of the end of the vessel when taking the cargo is composed of an increase in the average precipitate by the value of ΔT and changes in the sediment of the ΔT h and Δt k. The value of ΔT does not depend on the location of the received cargo, and the values \u200b\u200bof ΔТ H and ΔT k at a given sediment and the fixed mass of the PC will vary in proportion to the abscissa of Ts.T. Accepted cargo xp. Therefore, using such a dependence, it suffices to calculate the changes in the sediment of the end from receiving the goods first in the nose area and then the feed perpendicular and to build a scale or a table of changing the sediment of the vessel's finish from taking a weight, for example, 100 tons. V values \u200b\u200bΔT, ΔT h, ΔT k Calculated by formulas.

According to the increments of the sediment of the end of the vessel, we build a schedule for changes in these sediment from the receipt of the specified cargo.

To do this, on a straight line A - B we conceal the position of the Midel - the Spantom and put it in the selected scale to the right (in the nose) and left (in the stern) half the length of the vessel. Of the points obtained, we restore perpendicular to the line A - b. On the nose perpendicular laying up the segment b - in, depicting in the selected scale, the calculated change in precipitation with the nose when taking the cargo in the nose. Similarly, on the feed perpendicular, we lay down the segment A - G, depicting the calculated changes in the sediment with the nose when taking the cargo in the stern. By connecting the direct point in - r, we obtain a graph of changes in the sediment with a nose from the reception of a weight weighing 100 tons.

Fig. four

Δ T n \u003d + 24 s m \u003d 0, 24 m;

Δ T K \u003d + 4 s m \u003d 0, 04 m

In the same way, the schedule for changing the sediment of the vessel feeds from the reception of cargo is made. Here the segment B - D in the accepted scale depicts the change in the sediment with the feed when taking the cargo 100 tons in the nose, and the segment A - E - when taking the cargo in the stern.

We produce calibration scale. Over the schedule (or under it) we spend two straight lines for applying a precipitate change: the upper - for the nose, and the bottom - for the stern. At each of them, we note the points corresponding to divisions 0 (their position is determined by the points of intersection of the line A - B with graphs in G and E - D, i.e. the points of Zh - P). Then between the line A - B and graphs in G and the unit, we select such segments, the length of which in the accepted scale would be equal to 30 or 10 cm changes in precipitation. Such segments during the graduation of the scale "nose" will be segments from - and and cl. As a result, we get on the division scale 30 and 10 on the scale. The distances between 0 and 10, 10 and 20 are divided into 10 equal parts. The dimensions of these divisions on both sections of the scale should be the same.

Using a graph of E - D, in a similar way to build a precipitate for sipart feed. In practical calculations, there are several scales for changing the sediment of the end from receiving 100 tons of cargo. Most often, the scales for three precipitate (displacements) are built: the sediments of the empty vessel, the sediment of the vessel with full load and intermediate.

Scale, charts or tables of changes in the sediment of the vessel's ends from receiving a single cargo (for example, 100 tons) may have a very different look. Several such examples are given below in Figures 5-7.

Fig. 5 Changes Changes Changes Changes from receiving 100 tons of cargo combined with appropriate points on the vessel
Fig. 6 Scale of changes in the precipitation of the end of the vessel from receiving 100 tons of cargo, combined with the corresponding points on the vessel
Fig. 7.

Offered for reading:

On the stability of the cargo vessel when moving, its load has a great influence. The ship management is much easier when it is not completely loaded. The vessel, which is not having a cargo in general, is easier the steering wheel, but since the vessel's screw is close to the surface of the water, it has increased dustiness.

When accepting the cargo, and therefore, the increase in the sediment becomes less sensitive to the interaction of wind and the waves and is more resistant to the course. The position of the body relative to the surface of the water also depends on the load. (i.e. has a vessel roll or a differential)

From the distribution of cargo by the length of the vessel relative to the vertical axis depends on the moment of inertia of the mass of the vessel. If most of the goods are concentrated in the fodder holds, the moment of inertia becomes large and the ship becomes less sensitive to the perturbing effects of external forces, i.e. More sustainable on the course, but at the same time it is more difficult to appear.

Improving the turning time can be achieved by concentrating the most heavy loads in the middle part of the case, but with simultaneous deterioration in the resistance of the movement.

Placing goods, especially heavyweight, upstairs causes filling and roll roll, which adversely affects stability. In particular, the negative impact on the controllability is the presence of water under the slices of the hold. This water will move from the side to board even when the steering is deviated.

The trigger of the vessel worsens the flow of the body, reduces the speed and leads to a displacement of the point of application of the side hydrodynamic force on the housing into the nose or stern, depending on the difference in the sediment. The influence of this displacement is similar to the change in the diametrical plane due to the change in the area of \u200b\u200bthe nasal adjustment or the feed deadwood.

The feeder on the stern shifts the center of the hydrodynamic pressure in the stern, increases the resistance of the motion in the course and reduces turning. On the contrary, the trim on the nose, improving turning, worsens stability in the course.

In case of differential, the efficiency of the steering wheel may worsen or improved. With a differential on the stern, the center of gravity shifts to the feed (Fig. 36, a), the shoulder of the rotating point of the steering wheel and the moment itself decreases, the turnover is worsening, and the movement stability increases. With a differential on the nose, on the contrary, with the equality of the "steering forces" and, the shoulder and the moment are increasing, so the turnover is improving, but stability on the course becomes worse (Fig. 36, b).

With a differential on the nose, the vessel improves turning, the stability of the movement on the opposite wave increases, and vice versa, strong stern rolls appear on the associated wave. In addition, with a differential on the nose of the vessel, the desire appears to exit the wind on the front and the cessation of the walking of the nose under the wind in the rear.

With a differential on the stern, the ship becomes less turning. In front of the front, the ship is steadily on the course, but with the oncoming excitement it is easy to string from the course.

With a strong differential to feed, the vessel appears a desire to dump the nose under the wind. In the back, the ship is managed with difficulty, it constantly strives to bring the fodder to the wind, especially with the lateral direction.

With a small differential, the effectiveness of the drivers increases on the feed and most vessels increase the speed of the course. However, further increase in the differential leads to a decrease in speed. Different on the nose due to an increase in water resistance to movement, as a rule, leads to the loss of the speed of the front.

In the practice of shiping, the sink differential is sometimes specifically created when towing, when swimming in ice, to reduce the possibility of damage to the screws and steering wheel, to increase resistance when driving in the direction of waves and wind and in other cases.

Sometimes the vessel commits a flight, having some roll on any board. The roll can cause the following reasons: the improper arrangement of goods, uneven consumption of fuel and water, structural disadvantages, lateral pressure of the wind, accumulation of passengers on one board, etc.

Fig.36 Influence of the differential Fig. 37 Roll effect

Roll has a different impact on the stability of the single and two-screw vessel. With a roll, the simultal vessel does not go straight, but seeks to evade the course to the side opposite to the roll. This is due to the peculiarities of the distribution of water resistance for the vessel.

When moving the simulated ship without a roll on the cheekbones of both sides, two forces will be resist and, equal to each other in size and direction (Fig. 37, a). If you decompose these forces to the components, then the forces will be directed perpendicular to the sides of the cheekbones and they will be equal to each other. Consequently, the ship will go exactly at the rate.

When the ship rushes on the area "L" of the immersed surface of the joke of a loss of a lifted board larger the raised side of the raised side. Consequently, greater resistance of the oncoming water will be checked by the loss of the tail and the smaller - the cheekbar of the raised side (Fig. 37, b)

In the second case, water resistance strength and, attached to one and other cheekbone, are parallel to each other, but different in size (Fig. 37, b). With the decomposition of these forces according to the rule of the parallelogram to the components (so that one of them was parallel, and the other is perpendicular to board), make sure that the component is perpendicular to the board, more corresponding to the opposite side.

As a result, it can be concluded that the nose of the simulated vessel when the roll shies towards the raised side (opposite roll), i.e. in the direction of the smallest resistance of water. Therefore, to keep the single-ship in the course, you have to shift the steering wheel towards the roll. If the steering wheel will be in the "straight" position at the ship, the vessel will circulate to the side opposite to the roll. Consequently, when performing revolutions, the diameter of the circulation towards the roll increases, in the opposite direction - decreases.

Two-duty vessels from the course is caused by the joint effect of the unequal windshield resistance of water by the movement of the hull on the side of the vessel's sides, as well as various values \u200b\u200bof the impact of the unfolding efforts of the left and right machines with one number of revolutions.

At the vessel without a roll, the point of the application of water resistance forces is in the diametral plane, so the resistance from both sides has an equal impact on the vessel (see Fig. 37, a). In addition, the vessel does not have rolls, unfolding moments relative to the center of gravity of the vessel, created by the focus of the screws and, almost the same, since the shoulders of the stops are equal, and therefore.

If, for example, the vessel has a permanent roll on the left side, then the deepening of the right screw will reduce and increase the recess of the screws on the right side. The center of water resistance to the movement will shift toward the lone board and takes the position (see Fig. 37, b) on the vertical plane with which the movers with unequal shoulders of the application will operate. those. then< .

Despite the fact that the right screw due to a smaller blowing will work less efficiently compared to the left, however, with an increase in the shoulder, the overall turning point from the right car will become much more than from the left, i.e. then< .

Under the influence of more than the right car, the vessel will strive to decounded towards the left, i.e. Caught onboard. On the other hand, an increase in water resistance to the movement of the vessel from the side of the cheekbone will predetermine the desire to evade the ship towards elevated, i.e. starboard.

These moments are comparable to each other. Practice shows that each type of vessel, depending on the various factors, shied in a certain direction during the roll. In addition, it was established that the values \u200b\u200bof the evading moments are very small and they are easily compensated for by a steering wheel by 2-3 ° to the side of the side, the opposite side of the evasion.

The coefficient of the completeness of displacement.Its increase leads to a decrease in force and reduce the damping point, and therefore, to improve sustainability.

Form of the stern.The shape of the stern is characterized by an area of \u200b\u200bfeed podzer (underrbs) of the stern (i.e., an area of \u200b\u200bcomplementary feed to a rectangle)

Fig.38. To the definition of the area of \u200b\u200bthe feedstone:

a) feed with suspended or semi-lines;

b) feed with a wheel located for Ruderpost

The area is limited to the feed perpendicular, the liquid of the keel (baseline) and the feed circuit (in fig. 38 shaded). As a criterion, the feed of the feed can be used the coefficient:

where is the middle sediment, m.

The parameter is the coefficient of completeness of the DP area.

A constructive increase in the area of \u200b\u200bthe underrbs of the feed tip 2.5 times can reduce the circulation diameter by 2 times. However, sustainability will deteriorate sharply deteriorate.

Steering area.The increase increases the transverse power of the steering force, but at the same time increases the damping effect of the steering wheel. It is practically it turns out that an increase in the steering area leads to improved turning only at large corners of the smoker.

Relative steering elongation.An increase in its unchanged spaces to the growing power of the steering force, which leads to some improvement of turning.

Rule location.If the steering wheel is located in the screw stream, the speed of water flow on the steering wheel increases due to the additional flow rate caused by the screw, which ensures a significant improvement in the turning. This effect is particularly manifested in the simplicity of acceleration mode, and as the speed approaches the steady value decreases.

On duvunt ships, the steering wheel, located in the DP, has relatively low efficiency. If there are two fever steering on such vessels for each of the screws, turning sharply increases.

The effect of the velocity of the vessel on its handling appears ambiguously. The hydrodynamic forces and moments on the steering wheel and the vessel case are proportional to the square of the raid flow velocity, so when the vessel moves with the steady speed, regardless of its absolute value, the ratios between the specified forces and the moments remain constant. Consequently, on different steady speeds of the trajectory (with the same corners of the wheelchair) retain their shape and dimensions. This circumstance was repeatedly confirmed by natural tests. The longitudinal circulation size (extensive) is significantly dependent on the initial movement speed (when maneuvering from a small run runs 30% less than the eleg from the full stroke). Therefore, in order to make a turnover on a limited water area in the absence of wind and flow, it is advisable before starting the maneuver to slow down and perform turnover at a reduced speed. The smaller the water area on which the ship circulation is performed, the less should be the initial speed of its stroke. But if in the process of maneuver, change the speed of rotation of the screw, the flow rate of the flux by the steering wheel will change, located behind the screw. At the same time, the moment created by the steering wheel. It will change immediately, and the hydrodynamic moment on the housing of the vessel will be changed slowly as the velocity itself changes, therefore the former relationship between these moments will temporarily break, which will lead to a change in the curvature of the trajectory. With an increase in the rotational speed of the screw, the curvature of the trajectory increases (the radius of curvature decreases), and vice versa. When the vessel speed comes in accordance with the nasal rotation frequency of the screw, the curvature of the trajectory will again become equal to the initial value.

All of the above is true for the case of the sixth weather. If the vessel is exposed to the wind of a certain force, then in this case the handling significantly depends on the velocity speed: the speed is less, the greater the effect of wind on handling.

When for any reason it is not possible to allow an increase in speed, but it is necessary to reduce the angular speed of rotation, it is better to quickly reduce the speed of rotation of the drivers. It is more effective than the operating of the steering organ on the opposite board.

13.Notability The upper deck, which is a smooth lift of the deck from the face of the nose and in the stern, also affects the appearance of the vessel. There are vessels with standard saddles, determined by the rules about the cargo stamp, a court with a reduced or increased saddle and court without saddleness. Often, the saddle is performed not smoothly, but with straight areas with slots - two or three plots on half the length of the vessel. Due to this, the upper deck does not have a double curvature, which simplifies its manufacture.

The deckline for sea ships is usually the species of a smooth curve with a rise from the middle part in the direction of the nose and the stern and forms the sedlice of the deck. The main purpose of the saddle is to reduce the fillerness of the deck when swimming the vessel on the excitement and ensure non-passibility when flooding its tips. River and sea vessels with a large height of the surface board of saddles, as a rule, do not have. The lifting of the deck in the feed is installed, based on, primarily from the condition of non-optomasics and non-optimability.

14.Ged - This is the bias deck from the DP to the sides. Usually die have open decks (upper and decks of add-ons). Water falling on the decks, due to the presence of dots, flows to the sides and from there is given abroad. The arrow is killed (the maximum elevation of the deck in the DP in relation to the onboard edge) is usually taken equal to the V50 vessel width. In cross section, dying is a parabola, sometimes, to simplify the technology of manufacturing the housing, it is formed in the form of a broken line. Platforms and decks underlying the upper deck, do not have. The plane of the Middle Spangout divides the vessel body into two parts of the nasal and feed. The tip of the housing is performed in the form of cut (cast, wrought or welded). Nasal