Yachts with bilge keels. French cruising yacht with bilge keels

When a sailing yacht sails at an angle to the direction of the wind, a force is created on its sails, one of the components of which acts across the ship and causes the yacht to heel and drift. On a close-hauled course, the drift force is almost four times greater than the useful thrust force, which propels the yacht forward; on the gulfwind course the drift force and the thrust force are almost equal, and only on the gybe course there is practically no drift force.

The roll and drift of a yacht going close-hauled increases the resistance of the water to the movement of its hull and reduces the speed of the yacht in the direction of the wind. This is why stability and resistance to drift are the most important qualities, which determine the yacht’s ability to tack. These qualities are directly dependent on the vessel's draft. In fact, the stability of a yacht can be ensured by lowering its center of gravity or by creating a special, more stable hull shape.

In the first case, the required position of the center of gravity is achieved by laying internal ballast or installing a heavy false keel under the bottom of the yacht. The deeper the keel is sunk, the lower the yacht's center of gravity. Consequently, the need to sufficiently lower (deepen) the ballast is the first reason regarding large draft sailing yachts.

Since the yacht moves in the water at a drift angle to the heading, a lifting force is generated on its hull, counteracting the drift force. We know that when an airplane takes off along the airfield runway, the oncoming air flow hits the wings at a certain angle and creates a lifting force on them, which lifts the airplane off the ground. A similar phenomenon is observed when the yacht is moving. However, although water is 800 times more dense than air, a sufficient lift force cannot be generated on the hull of a yacht (as well as on the fuselage of an airplane); To do this, it is necessary to install unique hydrofoils in the form of fins, keels, centerboards under the bottom or along the sides of the yacht.

The narrower and deeper the keel, which works like an airplane wing, the greater the lifting force generated on it. On sports vessels, where speed is especially important, this is why narrow and deep keels are used, on which the greatest lifting force is generated with a minimum area. The effectiveness of this form of keels is the second reason for the significant increase in the draft of a sailing vessel.

Since the improvement sailing equipment, which made it possible to tack, the efforts of shipbuilders were aimed at creating full-fledged hulls of shallow-draft sailboats. Such vessels are needed for navigation in shallow waters along sea ​​coasts, in river mouths and areas with large fluctuations in water levels.

One of the first ships with a shallow draft were Dutch sailing ships with fenders. These sailing ships were wide vessels, which provided them with the necessary stability. To increase resistance to drift, instead of a deep keel, two large dowel boards were hung on the sides, which rose out of the water when passing through shallow areas. When tacking, usually only the leeward door was lowered.

Shverts are undeservedly forgotten by modern yachtsmen, although in the 18th-19th centuries there were many yachts with Shverts (including in Russia). The aerodynamic quality of narrow and long doors is quite high. Indeed, thanks to the installation of shverets, such vessels as flat-bottomed Temzin barges sailed close-hauled. Particularly successful are the swivels of the Dutch design, which remain vertical when the ship rolls (Fig. 1, a).

Rice. 1. Installation of bilge keels:
a - Swiss; b - double-deck vessel; c - yacht “Iris”; g - a yacht with bilge keels.

The screws do not take up space inside the body; no wells are needed for their installation. Even now, shverets are sometimes installed on yachts converted from lifeboats, since in this case the installation of a false keel is, as a rule, undesirable due to the increase in draft, and the gap in the keel for the passage of the lower keel violates the strength of the hull. However, controlling large-area swivels is very inconvenient. While underway and when grounded, the leeward shverd is strongly pressed against the side of the vessel by water pressure and it is difficult to lift it out of the water.

When mooring, the fenders are often damaged, and when rocking, they rub against the sides and damage the ship's hull. Therefore, despite all the improvements, centerboards were replaced by lowering keels - centerboards.

It is believed that the centerboard was invented in America at the end of the 18th century, but there is evidence of much earlier use. For example, the ancient Incas stuck several vertical narrow boards between the logs of their rafts. By changing the number and arrangement of boards, it was possible to adjust the position of the center of lateral resistance relative to the center of sail and thus change the course of the raft in relation to the wind.

After the invention of the centerboard, on some Temzin barges the centerboards began to be placed in wells inside the hull. This protected them from damage when sailing in such a “tight” place like the Thames. At first, such paired centerboards were installed parallel to the DP. Then, on sports ships, they began to be installed with an inclination to the diameter so that when heeling, the leeward centerboard became vertical and worked more efficiently (Fig. 1.6). The windward centerboard was usually chosen into the well to reduce the wetted surface; When sailing on a full course, both centerboards were retracted. In Russia, double-center vessels were known as “Ri-Ri” and had two rudders installed behind the centerboards.

In 1890, the first permanent yacht, the Iris, appeared. With a length of 18 and a width of 3.8 m, she had a draft of only 1.1 m. The keels on her were 3 m long and about 300 mm wide. Obviously, by installing such keels, the designer wanted, first of all, to give the yacht the property of stably landing on the ground at low tide (Fig. 1, c). Despite the shallow draft, the Iris showed good tacking qualities and was not inferior to its deep-draft rivals. This is how another type of shallow-draft yachts appeared - with bilge keels (Fig. 1, d).

The prototype of modern yachts with bilge keels is the Bluebird yacht, designed and built by the Englishman Balfour in 1924. 15 years later he built a new yacht with two keels and a steel hull. Balfour used a steel structure, since during the operation of the Bluebird it became clear that the strength of fastening the heavy false wings to the hull was insufficient. The new yacht had a maximum length of 14.6; waterline length 12; width 3.3 and draft 1.45 m. Interesting feature the yacht was the shape of its keels. The cigar-shaped ballast was suspended on a narrow steel sheet (Fig. 2), and the aft end of the ballast was supported by a streamlined post on which the rudder was hung. The keels were set at an angle of 10° to the vertical and provided effective resistance to the yacht's drift.

In 1936, the Buttercup yacht, 7.5 m long with two bilge keels, was built in England. Each keel was a three-hundred-kilogram lead casting mounted on a wooden fin. On the transom, on a separate fin, the steering wheel was hung. “Buttercup” tacked well, and during the transatlantic passage in 1956, another positive property of two-keel ships was discovered. On full courses and on a wave, when the pressure on the yacht's sails decreases, conventional yachts have very gusty roll and pitch. The zygomatic keels of the Buttercup significantly softened the rolling, increasing its period. The effect of a higher center of gravity than that of conventional yachts also had an effect. This contributed to the success of the thirty-day passage across the ocean, during which the yacht sailed mostly at full speed.

The widespread use of bilge keels for shallow-draft yachts began in 1955, after successful experiments in replacing the bulb keel with bilge keels on a small yacht. With this replacement, the draft became 300 mm instead of 700, and the seaworthiness and tacking qualities of the “new” yacht turned out to be no worse than with a bulbkeel. The roll under the sails almost did not increase, despite the decrease in the ballast depth.

In recent years, yachts with bilge keels - especially small yachts - have become very popular. In England, Germany, France and Holland, mass production of such vessels has been established, and often the same hull is supplied both as a yacht with bilge keels, and with a fin keel, and as a compromise. The choice of one or another type of keels is determined by the customer depending on the operating conditions of the yacht.

What are the features of yachts with bilge keels compared to keelboats, compromises and dinghies?

The effectiveness of the keel in generating sufficient drift resistance force, as mentioned above, depends to a large extent on the aerodynamic aspect ratio of the keel. The latter is estimated by the ratio T²/S , Where T - keel draft (from the bottom of the yacht to its lower edge), a S - keel area.

If you reduce the draft of a conventional type of keel yacht, you will have to increase the length of the keel line in order to keep the keel area unchanged. But at the same time, the relative elongation of the keel will decrease, and accordingly the force of resistance to drift will decrease; the yacht will tack with a large drift angle. With a significant decrease in the draft of the keel yacht, the drift will reach an unacceptable value (12-18°) and it will become advisable to install a lowering keel passing inside the ballast false keel. The result is a compromise solution that combines the features of a keelboat and a dinghy, which is why such yachts are called “compromises”. With the centerboard raised, the compromise maneuvers poorly, thanks to the false keel, but for normal tacking the compromise requires the same depth of the fairway as for a conventional keel yacht. That is why a compromise often cannot satisfy the requirements of a tourist or sports swimming enthusiast.

A dinghy has the shallowest hull draft of all types of sailing yachts, but it is impossible to maneuver on it with the centerboard retracted due to the flat-bottomed shape of the hull.

The operating experience of the first yachts with bilge keels showed that with a draft equal to 50-60% of the draft of a normal keel yacht, they tack no worse.

Table 1. Comparison of main types of yachts.

In table 1 shows comparative data on yachts of four main types with a sail area of ​​about 20 m² and approximately the same length along the waterline. The features of a yacht with bilge keels (a two-keel yacht) are also visible from its comparison with a conventional keel yacht, shown in Fig. 3.

When close-hauled, the keel of a conventional yacht works less efficiently with increasing roll due to the increased inclination of the keel to the water surface (the projection of the keel on the vertical plane decreases); at the same time, the vertical component from the forces of water pressure on the keel increases, which creates an additional heeling force. The greater the roll, the greater the drift angle the yacht moves. When a yacht with bilge keels rolls, the leeward keel plunges deeper into the water, and its plane approaches the vertical; drift resistance increases, and the vertical component of water pressure on the keel is practically absent.

In the upright position, the draft of a two-keel vessel is 40-60% less than the draft of a keel yacht. When heeling, the draft of a keel yacht decreases, while that of a two-keel yacht, on the contrary, increases. When grounded with a list, a conventional keel yacht sits more tightly and is much more difficult to remove.

When the yacht rolls, the forces acting on the sails and hull lie in different vertical planes.

As a result, a driving moment appears, which makes it difficult to control the yacht. The shoulder of this moment in a two-keel yacht turns out to be smaller than in a regular one; therefore, the center of sail of a two-keel yacht should lie forward of the center of lateral resistance by a smaller amount than that of a conventional yacht. Due to the lower draft, the heeling moment arm on a yacht with bilge keels is also less than on a conventional keel yacht.

Two-keel yachts are very convenient for areas with large fluctuations in water levels and shallow anchorage. At low tide, such yachts do not fall on board, but stand on the keel and stern fin.

A two-keel yacht, having a shallow draft, does not have the design flaws inherent in a dinghy or a compromise. She does not have a centerboard well, which takes up space in the cabin and causes a lot of trouble with its water leakage. Finally, there is no centerboard itself, which can bend when running aground or simply get jammed in the well with a floating chip. And most importantly, neither the dinghy nor the compromise can tack with such a shallow draft as a yacht with bilge keels. All this makes us pay attention to this type of sailing yacht and recommend it for widespread use in shallow water areas of our country.

Modern yachts with zygomatic keels, two types are built - with light and heavy zygomatic keels. For yachts of the first type (Fig. 4, a), the ballast keel is mounted on a low fin in the DP, i.e., in the same place as for conventional yachts, and the bilge keels are made of lightweight construction - from steel sheets, plywood or fiberglass.

Rice. 4. Modern types of yachts with bilge keels:
a - a yacht with light bilge keels and ballast in the DP; b - yacht with ballast on the bilge keels.

In yachts of the second type (Fig. 4, b), ballast keels are attached to the bilge keels, and the fin in the DP is made only in the stern for hanging the rudder.

From the point of view of stability, both methods of placing false fins are equivalent, since the center of gravity of the ballast lies at the same depth below the waterline. However, in the first case, the weight of the ballast is better absorbed by the rigid keel beam and distributed over the transverse set; in this case, the strength of the fastening of the light bilge keels should be designed only for the effect of resistance to drift and the reaction that occurs when the yacht runs aground. The drift force on a yacht with a sail area of ​​20 m² can reach 200-300 kg, so the bottom where the bilge keels are installed must be adequately reinforced.

Sometimes the fastening of such keels is deliberately made weak, so that if there is an excessive load (for example, when hitting a stone on a wave), the keel breaks away from the hull without violating the waterproofness of the outer skin. In this case, the keel is attached with screws to the overhead sheathing belt, and not a single screw should go into the main belt. If ballast is attached to the bilge keels, the design of the latter's attachment to the hull must be very reliable. If the keels are insufficiently tied to the hull frame, the skin straps become loosened and water leakage occurs. Typically, such keels are fastened with through bolts to durable stringers and floors. The stringers must be well connected to the frame frames and bulkheads, as, for example, this is done on a 7.5-meter yacht (Fig. 5).

1 - bilge keel, steel δ - 13; 2 - overhead strip 100X3, steel; 3 - bulkhead (wood);
4 - bolt Ø12; 5 - bolt Ø8.

The zygomatic carinae are usually placed at an angle of 8-15° to the vertical, either on the cheekbone itself, or at a distance of 1/4 of the width from the DP. When installing keels, you need to carefully check whether they will distort the smooth flow of water around the hull. Sometimes bilge keels are placed so that the distance between their bow edges is less than between the stern ones (the angle between the keel and the DP line at half latitude is 1-2°). Due to this, the angle of attack of the keel on a close-hauled course increases, and, consequently, the force of resistance to drift increases with a corresponding decrease in the drift angle. However, at full courses the resistance of such keels will be slightly greater than that of parallel keels.

Experiments conducted with a two-keel yacht showed that when replacing the fin keel with bilge ones, the area of ​​each of them should be equal to 60-70% of the area of ​​the fin keel. This area ensures good tacking qualities of the yacht. The area of ​​each keel should be about 1/35-1/40 of the area of ​​the sails.

As already noted, the bilge keel should be as short as possible (along the length of the yacht) in order to have good aerodynamic aspect ratio. Low keels, extending over most of the yacht's length, are ineffective and must have a very large area.

If ballast is attached to a fin in the DP, this fin must have a minimum area, otherwise the centering of the yacht will deteriorate. In this case, the rudder is hung on a separate fin under the stern valance; such a fin is necessary for support when the yacht runs aground and to protect the rudder blade.

The cross-section of the keel has a great influence on the resistance to drift. In their simplest form, bilge keels can be made flat from sheets of metal or bakelized plywood. But the results will be better if you install thicker profiled keels. The sections of such a keel are a special streamlined profile (Fig. 6). The keels of conventional keel yachts have a symmetrical profile (Fig. 6, a) with a relative thickness b/L= 0.10-0.14. Compared to a sheet keel of equal area and elongation, a profiled keel increases lift does not, but its drag is much less. At large drift angles (10-12°), the resistance of a profiled keel is 2-2.5 times less than that of a sheet keel. At small drift angles, thinner profiles ( b/L= 0.06-0.08) have a slight advantage over thick ones.

Rice. 6. Profiled keels:
a - symmetrical profile; b - asymmetrical profile.

Profile ordinates (dimensions b in % of chord).

Since on a yacht with bilge keels only the leeward keel actually works, it is advisable to use an asymmetrical (aviation) section profile (Fig. 6,b). Compared to a symmetrical profile keel, such a keel has a slightly increased drag, but its lifting force is 25-50% greater. Consequently, thanks to the use of such a profile, it is possible either to install a keel with a smaller area, or to tack with a smaller drift angle. Note that the increase in the lifting force of asymmetrical profiles occurs due to the greater pressure difference on the side surfaces of the profile.

The zygomatic keels of an asymmetrical profile should be installed with their convex surfaces towards the DP; only in this case will they work correctly and their installation will be justified.

The profiled keel can be made of wood or metal. The wooden keel is assembled from bars with through bolts, which secure the keel to the hull assembly. Metal keels can be cast or welded - from sheets of steel or aluminum alloys (Fig. 7). These keels usually have a flange for attaching to the hull.

The above discussed mainly the advantages of yachts with bilge keels, but it should also be noted that there are disadvantages that limit their scope of application to shallow water areas. Due to the small depth of the ballast, the stability of a yacht with bilge keels is somewhat less than that of a regular one. It is very difficult to impart sufficiently effective aerodynamic extension to the bilge keels. Due to the fact that only one leeward keel practically works, the total area of ​​the bilge keels is 20-25% larger than the keel area of ​​a conventional keel yacht, which increases the wetted surface of the hull and water resistance.

To ensure sufficient stability of a yacht with bilge keels, it is necessary to increase the height of its freeboard and width; this preserves sufficient form stability shoulders at high roll angles.

In Fig. 8 shows drawings of a small vessel with bilge keels (French construction).

enlarge, 1500x1845, 306 KB
Rice. 8. Drawings of a cruising yacht with bilge keels:
a - theoretical drawing; b - appearance; c - general location.
1 - sofa bed; 2 - hanging bunk; 3 - latrine; 4 - boxes; 5 - galley; 6 - folding table; 7 - cabinet: 8 - shelf; 9 - canister with water; 10 - canister with gasoline; 11 - sail box; 12 - outboard motor.

The yacht has high seaworthiness and can be used for coastal navigation, as well as for navigation on large lakes and reservoirs. The large width (L/B = 2.7) combined with a slight deadrise of the bottom provides good stability. The bow frames have a high deadrise, which softens the impact of the hull on the wave when tacking. Buttock lines, flat at the bow and smoothly emerging from the water at the stern, indicate the yacht’s good wave-survivability and propulsion.

The sheer line is typical of modern small cabin yachts - sheer up, which allows for increased side height in the middle part of the yacht, where the berths are located.

The yacht is designed for sailing three to four people. In the cabin there are two berths 1850X650; the third berth - a tubular one - is suspended on the port side in the forepeak. The deckhouse coamings are a continuation of the sides, which makes the cabin more spacious. The forepeak is separated from the cabin by a plywood bulkhead. On the left side in the forepeak there are lockers, a latrine and a wardrobe for shore clothes. On the starboard side there are lockers for stores and supplies. For the convenience of working with the anchor chain and staysails, there is a fore hatch. The cabin on the starboard side has a galley with a folding table; There are cupboards for utensils in the bow above the berth. The height of the cabin at the entrance is 1400 mm.

The yacht's cockpit (1600X1100) is self-draining. Sails, tools, as well as 20-liter canisters of gasoline and water are stored in the side niches near the cockpit. Aft of the cockpit there is a well for an outboard motor with a power of 5-7 liters. With. This design is very convenient to use, since the motor is always ready to start, is well protected from damage and does not require a special storage space. During long-term parking, the well can be closed from above with a hood with a lock. A stationary engine, for example the “SM-255-L” type, can also be installed on the yacht.

Total area sails is 20 m². The staysail stay is attached to the top of the mast, which allows you to increase the sail area by 4-5 m² in light winds by setting the balun. The center of sail is shifted forward from the center of lateral resistance by 5% of the length along the waterline. The mast is a tilting mast, installed in a stander on the roof of the cabin, supported by two rigid frames. The main sheet is mounted on a stand installed in the cockpit.

The keels, with an area of ​​0.8 m² and a weight of 235 kg, are placed at an angle of 5° to the vertical and bolted to reinforced floors.

The hull design is typical for yachts of this type. The oak keel is glued to the laminated stem. The paneling is made of pine 20 mm thick. The cross-section of the frames is 25X30, the spacing is 200 mm. The deck, deckhouse roof and cockpit are made of waterproof plywood 8-10 mm thick. This yacht can also be built with glued laminated cladding.

D. A. Kurbatov.

Drawings and description of the process of building a small cruising yacht with bilge keels.

Zygomatic keels are long plates installed in the cheekbone area along the streamline (Fig. 5.6). Representing a very simple design that does not take up useful volumes inside the ship, and at the same time creating a noticeable calming effect, bilge keels have become very widespread and are currently used in all fleets of the world.

The effect of zygomatic keels is to artificially increase the rolling resistance, so it manifests itself most effectively at large rolling amplitudes in the resonance zone.

Rice. 5.6. Zygomatic carinae

Typically, the total area of ​​the bilge keels is taken from 2 to 4% of LB, the height of the keels is from 0.3 to 1.2 m depending on the type of ship, on average 3-5% of the width of the ship. Their length usually ranges from 25 to 75% of the length of the ship. The installation location is the bilge rounding, and so that the keels do not protrude beyond the midsection dimensions. The keel line must be consistent with the stream line determined by model testing.

Structurally, the keels are made in the form of a sheet mounted on an edge. When the keel height exceeds 400 mm, strip or semicircular iron is placed on the free edge of the sheet. When the keel height is more than 600 mm, the keel is made in the form of a dihedron, into which ribs are welded for rigidity.

The influence of the side keels on the speed of the vessel is small. For high-speed ships, the reduction in speed in calm water does not exceed 2-3%. In rough weather, this decrease in speed is even less.

Serving primarily to ensure the strength of the ship's hull, the main purpose of the side keel is to reduce lateral motion during movement. They are long plates installed along the side in the cheekbone area, which is where their second name comes from.

Device

Side keels are the simplest and most common passive roll dampers. In most cases, side (side) keels consist of a protruding rib, attached directly to the ship's hull on the zygomatic part of the rim. They are located in the middle part of the ship, ½ - ⅔ of its entire length. As a rule, the height of the lateral carinae ranges from thirty centimeters to 0.75 meters.

On ships with a full midsection, there is virtually no need to install side keels.

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Notes

1. Krylov A. N.// Encyclopedic Dictionary of Brockhaus and Efron: in 86 volumes (82 volumes and 4 additional). - St. Petersburg. , 1890-1907.
2. Samoilov K. I. Marine dictionary. - M.-L. : State Naval Publishing House of the NKVMF of the USSR, 1941.
3. , With. 561.
4. // Military Encyclopedia: [in 18 volumes] / ed. V. F. Novitsky [and others]. - St. Petersburg. ; [M.]: Type. t-va I.V. Sytin, 1911-1915.

Literature

Links

An excerpt characterizing the Onboard Keel

The invention relates to shipbuilding, in particular to bilge keels. The bilge keel contains a longitudinal plate secured to the bilge of the ship's hull by means of an intermediate backing plate. A bent plate, made in the form of an isosceles square, is attached at its apex to the longitudinal plate symmetrically with respect to its axis. The height of the square, measured along the axis of symmetry, is equal to 0.2-0.35 of the height of the keel, and the angle between the sides of the square is 60-90. EFFECT: increased efficiency in calming the ship's motion. 1 ill.

The invention relates to the field of shipbuilding, in particular to bilge keels.

There are known zygomatic keels of a split or lattice design, in which the keels consist of individual plates, installed in rows and interconnected by a strip of rigidity (Shmyrev A.I. et al. Roll dampers for ships, Shipbuilding, 1961, pp. 14, 227). This design of bilge keels has not found practical application due to low strength and low manufacturability.

The design of a plate keel is known, in the design of which the longitudinal plate is made with concave sections of the upper and lower free surfaces symmetrically located in height, alternating with kinks (AS No. 506238, V 63 V 39/06, 3/44). This design has not been widely used due to difficulties in manufacturing, as well as increased requirements for precision processing and installation.

The most widely known are lamellar bilge keels containing a longitudinal plate, which is fixed to the bilge of the ship's hull by means of an intermediate backing strip, and on the free edge of the plate is fixed an edging profile made of a rod or a pipe, and sometimes from a strip-bulb profile - RD5.1002-80 " Chine keels of surface vessels and ships", pp. 11, 12.

However, such bilge keels are not effective enough in calming the rolling of ships.

The purpose of the proposed technical solution is to increase the efficiency of vessel motion control.

This goal is achieved by the fact that the zygomatic keel is equipped with an additional bent plate, made in the form of an isosceles square and attached at the top to the longitudinal plate symmetrically to its axis, while the height of the square, measured along the axis of symmetry, is equal to 0.2-0.35 of the height of the keel, and the angle between the sides of the square is 60-90.

The drawing shows the proposed keel. The bilge keel contains a plate 3, fixed to the bilge of the ship's hull 1 using an intermediate strip 2, and a bent plate in the form of an isosceles square 4, attached to the outer edge of the plate 3.

The device works as follows. While sailing in rough seas, forward and vertical movement is observed, as well as roll of the ship. In this case, a transverse flow of liquid flows around the zygomatic keel with an increased angle of attack due to the concavity of the upper and lower surfaces of the keel formed by the plate and the sides of the angle, i.e. with increased intensity of wave and vortex formation simultaneously on two outer edges, which ensures effective operation of the keel both when lowering and when lifting the vessel.

FORMULA OF THE INVENTION

A bilge keel containing a longitudinal plate secured to the bilge of the ship's hull by means of an intermediate backing strip, characterized in that, in order to increase operational efficiency, it is equipped with an additional bent plate made in the form of an isosceles square and attached with its apex to the longitudinal plate symmetrically with respect to it axis, while the height of the square, measured along the axis of symmetry, is equal to 0.2-0.35 of the height of the keel, and the angle between the sides of the square is 60-90.

The invention relates to shipbuilding and concerns the creation of bilge ship keels that allow the utilization of wave energy. The bilge keel is made in the form of a blade located on the underwater part of the vessel's hull. The blade is hingedly attached to the ship's hull, with the ability to rotate relative to the horizontal axis. One of the surfaces of the blade is pivotally connected to a hydraulic cylinder rod equipped with a piston. The hydraulic cylinder is pivotally connected to the ship's hull. The cavities of the hydraulic cylinder on both sides of the piston are connected to the hydraulic accumulator. The bilge keels are placed symmetrically relative to the longitudinal axis of the ship's hull. The technical result of the implementation of the invention is to expand the functionality of the device while providing the possibility of obtaining additional energy. 1 ill.

The invention relates to the field of shipbuilding and can be used in the designs of seaworthy ships, while the use of the proposed device allows one to obtain an additional source of energy by utilizing the wave energy that causes the ship to rock. A wave power plant is known, containing hingedly connected floats and deformable chambers of variable volume placed above and below the hinge, connected to power devices (see AS USSR N 1213239, F 03 B 13/20, 1986). The disadvantage of this solution is the impossibility of using it as a bilge keel (roll stabilizer), since it is impossible to rigidly fix one float relative to another and, accordingly, there is no resistance to the ship's rolling from side to side; in addition, the known design will have great resistance to the movement of the ship. A bilge keel is also known, made in the form of a blade located on the underwater part of the ship’s hull (see Marine Dictionary, M., Transport, 1965, 114 pp.). The disadvantage of this solution is the limited functionality of the device. The problem to be solved by the stated solution is expressed in expanding the functionality of the device. The technical result obtained when solving a functional problem can be defined as providing the possibility of obtaining additional energy. The problem is solved by the fact that the bilge keel, made in the form of a blade located on the underwater part of the ship's hull, is distinguished by the fact that the blade is hingedly attached to the ship's hull, with the possibility of rotation relative to the horizontal axis, while one of the surfaces of the blade is hingedly connected to the equipped a piston, a hydraulic cylinder rod, pivotally connected to the hull of the vessel, while the cavities of the hydraulic cylinder on both sides of the piston are connected to the hydraulic accumulator, while the bilge keels are placed symmetrically relative to the longitudinal axis of the hull of the vessel. A comparative analysis of the features of the claimed solution with the features of the prototype and analogues indicates that the claimed solution meets the “novelty” criterion. The features of the distinctive part of the formula of the invention solve the following functional problems: The feature..."the blade is hingedly attached to the hull of the vessel, with the ability to rotate" gives the blade mobility and, thereby, provides the ability to "remove" the energy perceived by the blade during its interaction with the surrounding aquatic environment . The feature that determines the orientation of the axis of rotation of the blade provides the possibility of utilizing the energy of the ship's lateral motion. The signs “one of the surfaces of the blade is pivotally connected to an equipped piston, a hydraulic cylinder rod, pivotally connected to the hull of the vessel” describes a mechanism that ensures the conversion of the “rocking” movements of the blade into mechanical energy. The feature “the hydraulic cylinder cavities on both sides of the piston are connected to the source of the working fluid” provides the possibility of fixing the blade in a given position and even the possibility of actively counteracting pitching by appropriate movement of the blades. The feature “the bilge keels are placed symmetrically relative to the longitudinal axis of the ship’s hull” ensures symmetry of the forces on the ship’s hull that occur during operation of the device. The drawing schematically shows the claimed device. The drawing shows the side 1 of the vessel, blade 2, hinges 3, rod 4, cylinder 5, hydraulic accumulator 6, hydraulic distribution unit 7, pipes 8 and 9, pipelines 10, piston 11, gearbox 12, sea surface 13. Blade 2 is hinged to the body vessel with the ability to rotate relative to the horizontal axis due to the hinge 3. The rod 4 and cylinder 5 form a double-acting hydraulic cylinder, the cavities of which, located on both sides of the piston 11, are connected through pipes 8 and 9 and pipelines 10 to the hydraulic distribution unit 7 of the hydraulic accumulator 6. The cylinder body 5 and the end of the rod 4, through hinges 3, are connected, respectively, to the side of the vessel and the blade 2. As a hydraulic distribution unit 7, any device of a similar purpose can be used that satisfies the operating conditions in its characteristics and has remote, preferably automated control of channel switching. High pressure hoses are used as pipelines 10. As a reducer 12, a valve device of a known design is used, which ensures the supply of liquid to the pipeline 10 with a pressure lower than in the accumulator. The claimed device works as follows. When the device is operating in power plant mode. The hydraulic distribution unit 7 is in a state that ensures the sequential release of fluid compressed in the cavity of the hydraulic cylinder 5 into the cavity of the hydraulic accumulator 6 through the pipe 8 and the corresponding pipeline 10, and the reverse discharge (filling) into the cavity of the hydraulic cylinder 5 of liquid under low pressure from the cavity of the hydraulic accumulator 6 through the gearbox 12, pipe 8 and the corresponding pipeline 10. In this case, the blade 2 has complete freedom of movement. When, as a result of lateral rolling, the corresponding side 1 of the ship is immersed deeper into the water, a hydrodynamic force acts on the blade 2, tending to turn the blade with its free end towards the sea surface 13. This leads to the movement of the piston 11 inside the cylinder 5 and then the release of the compressed fluid into the cavity of the hydraulic accumulator 6, when the ship's hull moves in reverse side, the piston goes down, and the cylinder cavity is filled with working fluid under low pressure, then everything is repeated. This ensures constant “pumping” of the hydraulic accumulator with compressed fluid, which is used to drive the corresponding machines and mechanisms or for other purposes. When the device is operating in zygomatic keel mode. The hydraulic distribution unit 7 is in a state that ensures the supply of high-pressure fluid from the cavity of the hydraulic accumulator 6 into the cavity of the hydraulic cylinder 5 (on both sides of the piston 11). In this case, the blade 2 is fixed at a certain angle to the hull of the vessel. When, as a result of lateral rolling, the corresponding side 1 of the ship sinks deeper into the water, a hydrodynamic force arises on the blade 2, tending to prevent such a rotation of the ship's hull. In this case, the hydraulic cylinder rigidly fixes the position of the blade 2.

Formula of invention

A bilge keel is made in the form of a blade located on the underwater part of the ship's hull, characterized in that the blade is hingedly attached to the ship's hull, with the possibility of rotation relative to the horizontal axis, while one of the surfaces of the blade is pivotally connected to a hydraulic cylinder rod equipped with a piston, pivotally connected to the hull of the vessel, while the cavities of the hydraulic cylinder on both sides of the piston are connected to the hydraulic accumulator, while the zygomatic keels are placed symmetrically relative to the longitudinal axis of the hull of the vessel.