NO322547B1 - Hybrid craft for high speeds - Google Patents

Description

HYBRID MARINE VESSEL

The invention generally relates to marine vessels and in particular a hydrofoil assisted speed boat hull consisting of a slim center hull element and two or more side hull elements, where the vessel in normal fast moving condition mainly operates as a hydrofoil stabilized super-slim monohull vessel.

Among modern speedboat concepts, the catamarans have taken a dominant market position as monohull vessels during the last two 10 years, especially in sizes under 100 metres. This type of vessel is characterized by its operational simplicity, good stability and relatively good speed and sea characteristics, especially in the speed range between 30-35 knots. However, the market seems to make higher demands on speed, and several catamarans that do 45 knots, and exceptionally over 50 knots, have recently become a reality. These requirements have resulted in larger engine installations and the introduction of active stabilization systems to reduce movements, such as T-foils located in the bow area and trim flaps or interceptors located aft. However, the introduction of T-foils, which are mainly non-lift generating devices, introduces a significant drag that reduces the speed by about 2-3 knots on a 40-45 knot catamaran.

In parallel with increased requirements for speed on special routes, most operators are still hesitant to join this development trend due to the fact that it results in a sky-high increase in fuel consumption. It is very likely that the catamaran technology, which was originally commercially developed in the early 70s, has today reached its optimal stage of development from a hydrodynamic point of view. Further reduction of drag is severely limited by the fact that the main drag component is related to viscous hull friction. To solve this, either the wet bag surface must be reduced, or the viscous hull friction must be reduced by applying new technology, such as e.g. air lubrication.

Acknowledgment of a lack of proven methods to solve these technological challenges indicates that the catamaran concept, as we know it today, is no longer particularly suitable to fully meet the future market needs in all respects. This view is supported by the increased attention to environmental issues among the population and authorities, which will probably force the development of new and better concepts in this regard. The environmental impact of the speedboats' tendency to create waves has also caused increased regional concern.

Previous technology

The surface shear hydrofoils were commercially developed in the mid-1950s and mass-produced by Rodriquez, Italy. As is known, these are based on a monohull vessel equipped with a fore- and aft-placed surface-cutting hydrofoil arrangement, which in the transverse direction consists of a V-like hydrofoil span. Thus, parts of the foil span protrude through the waterline on both sides, and provide a transverse ship's righting moment when the vessel capsizes and forces the surface foil span underwater. The hull is lifted completely out of the water at higher speeds, in which condition it is self-stabilizing transom and longboard due to the surface cutting foil arrangement. Propulsion is provided by fully submerged propellers mounted on inclined shafts. This design concept's advantage over traditional monohull vessels of similar size was better seaworthiness and performance / speed efficiency at a cruising speed of around 35 knots. The downside was increased complexity, construction cost, weight and speed limitation. Consequently, the design is generally limited to a maximum length of around 40 m and a maximum displacement of around 150 tonnes. The design became very popular as passenger boats, and today there are still large numbers in operation around the world, mainly in the former Soviet republics, Japan and the Mediterranean countries. In the opinion of the inventor, there is probably so far no other speedboat concept that has accumulated the same number of transported passengers. Compared to modern speedboats such as catamarans and monohulls, the concept has lost its popularity, and can no longer compete in terms of speed requirements and passenger comfort, although it remains a leader in terms of speed/performance efficiency.

One of the most significant steps in the development of speedboat technology came in the mid-70s when Boeing, USA, developed the JetfoiPen. Similar to the hydrofoils from Rodriquez, the concept is based on a monohull vessel that is lifted clear of the waterline at higher speeds. However, the foil system is based on the fully submerged type which consists of a completely flat fully submerged foil span supported by three vertical supports. Unlike a surface-cutting foil, it is not self-stabilizing, and therefore depends on adjustable flaps integrated into the trailing edge of the foil span. The main foil is positioned aft, extends across the vessel's full width and provides primary lifting power and transom stability. A smaller foil (T-foil) is placed in the center line ahead, fixed on a vertical support. This provides the secondary lifting force in addition to the necessary longship righting moment. All the foils can be tilted upwards when the vessel is resting at full displacement. The 27.4 m and 117 tonne Jetfoil design has a normal cruising speed in the lifted state of around 45 knots. This design enjoys the advantage of excellent sea characteristics and high speed / performance efficiency The downsides, however, are high construction costs, technical complexity, weight and payload limitations.

In the early 90s, Kværner Fjellstrand and Westamarin developed the Foilcat concept. This is basically a catamaran equipped with a fully submerged foil system that lifts the vessel above the waterline, and operates at a cruising speed of around 45 knots. The largest design is 35 m and has a maximum displacement of 175 tonnes. It is described in Norwegian patent no. 175199. The design mainly has the same advantages and disadvantages as the Jetfoils. This has limited its commercial penetration.

In order to reduce the large frictional resistance that characterizes catamarans operating at a cruising speed of around 45 knots, there has recently emerged a trend towards developing foil-assisted catamarans equipped with a fully submerged foil system in order to partially lift the hull out of the water. time it controls stomping, and to a lesser extent rolling and heaving movements. Examples of this are US 4606291 and US 4665853. Since the design operates in a partial displacement state, and as such still has two submerged hulls, they will still be subject to a significant frictional resistance.

The trimaran design has gained an increased reputation within the sailing community due to its good speed and seaworthiness. As is known, the trimaran concept consists of three fully submerged hull elements, and includes a longer narrow center hull and a pair of shorter outriggers or side hulls, integrated to the underside of a transom support structure placed amidships or aft. However, the design has not yet been adopted in the speed boat market. Variations of this design are described in various patents and patent applications, such as US 4348972, US 5178085, US 5529009, JP 63130492, WO 93/07046, WO 94/20359, WO 97/10988 and EP455605. Some of these include lifting devices in the form of T-foils mounted on the side hulls and the center hull in order to dampen rolling and pitching movements. However, all operate in a permanent displacement state with three submerged hulls.

A foil-assisted hybrid marine vessel is described in US patent no. 5503100. However, this invention seems to be burdened with a number of impractical features which will probably make the invention unusable as a speed boat. The reason for this is the combination between its complex hull shape and unorthodox propulsion and foil arrangement, which will result in excess weight and high frictional resistance.

The invention

In a preferred embodiment, the current invention is a hybrid between a monohull vessel and a trimaran. As is known, the so-called Froude's number expressed by the formula;

where, v = velocity (m/s), g = acceleration constant (9.81 m/s<A>2), L = waterline length (m),

an important role in determining a vessel's wave resistance. Traditional trimarans with fully submerged side hulls tend to operate in a planing regime when the length of the side hulls is short and the speed sufficiently high. Because of. of that the stability requirements

indicates a certain positive metacenter height (+ GM), the side hulls tend to have a relatively large dip in relation to the length, which entails a general risk of significantly increased wave resistance at higher Froude numbers.

The current invention is based on a hybrid hull geometry consisting of a combination between an improved variant of the above-mentioned trimaran and a monohull vessel, consisting of a deep narrow center hull element and at least a pair of narrow and shallow side hull elements integrated to the vessel via a rigid deck construction that connects the side hull elements to the center hull element, and operating in two distinctly different states, namely a hydrostatically stable lower speed condition with a positive meta-center height (+ GM) with the center hull element and at least one of the side hull elements submerged, and a hydrostatically unstable higher speed condition with a partially lifted, partially submerged center hull element with a negative metacenter height (- GM) while the side hull elements are partially or completely above the waterline, and where the transition from one state to the other is aided by hydrodynamic lift-generating, heel-, heave- and pitch-regulating wings or hydrofoils, in that vessel is characterized wood n combination of the following features;

that the center hull element itself has a large waterline length in relation to the width i

the waterline, and a large main deck width in relation to the width of the waterline;

that the center hull element below its wet deck level has a transom section as shown in figures 4a-d and 4e-m over a larger part of its length, possibly a combination of these;

that the side hull elements have a depth that is less, possibly significantly less,

than the depth of the center hull element, possibly with an adjustable height, and placed in such a way in the longship direction that a larger part lies aft of the vessel's longship center of gravity, or close to said center of gravity, and symmetrically around the vessel's centreline;

that at least one primary hydrodynamic wing or hydrofoil device is placed between and below the center hull element and the side hull elements, integrated to these by means of vertical supports, possibly also to the intermediate wet deck structure, through at least one vertical support on each side of the vessel's centreline;

that at least one secondary hydrodynamic wing or hydrofoil device is placed in an aft or forward position on the center hull element, possibly in both places, integrated to the vessel through at least one vertical support for each set of hydrofoil device, possibly also to the intermediate wet deck construction;

that the wings or hydrofoils are positioned so that the center of hydrodynamic lift is

located at or near the vessel's longship center of gravity;

that the hydrodynamic lifting force generated by the hydrofoil devices at

maximum speed is at least 20% of the lightest weight of the vessel;

that the side hull elements consist of structurally integrated or independently attached elements placed below the wet deck and made of a rigid construction material or a flexible shock-absorbing elastomeric material throughout its length, or over a greater part of its length;

that the side hull elements contain floating elements that are adjustable in height above

the entire length of the side hull elements, or over a greater part of their length;

that the center hull element, preferably on larger vessels, is equipped with a water ballast tank with a permanent opening located in the bottom plate of said hull element at a distance in front of the aft end of said hull element, for rapid self-filling and emptying, possibly equipped with a device for remote-controlled filling and emptying;

In a preferred embodiment, the vessel is equipped with a fully submerged lift-generating roll-stabilizing and heave-damping primary hydrofoil device located below and between the center hull element and the side hull elements, close to the vessel's center of gravity (LCG), and attached to the center hull element, to the intermediate wet deck structure and the side hull elements, by means of vertical, possibly also inclined supports, and a secondary hydrodynamic lift-generating and trim-regulating hydrofoil placed aft, alternatively forward or both places, and attached to the center hull element, possibly also to the intermediate wet deck structure, depending on the hydrofoil device's transom span, by using vertical supports.

In another preferred embodiment, particularly suitable for vessels larger than 100 m, the vessel is equipped with two primary lift-generating, heel-stabilizing and trim-regulating primary hydrofoils with a high aspect ratio. Since vessels of this size normally have a displacement in excess of 1,000 tonnes, with regard to optimization of overall resistance, it may be desirable that the foil span be increased beyond the vessel's normal width in order to achieve a lift/displacement ratio of 50% at 40 - 45 knots speed. Such an arrangement is shown in Figure 8. Here, parts of the deck structure are extended transversely beyond the normal width of the vessel with the intention of providing a foundation for the outer foil supports. These foundation structures can also accommodate facilities for mooring, as well as embarkation and disembarkation.

For larger versions, such as around 200 m or larger, an arrangement of three primary lift generating foils may be feasible. In such a case, the approximate location of the foils should be aft, forward and amidships.

Best condition

High-speed hybrid marine vessels according to the current invention are equipped with hydrodynamically lift-generating, pitch-, heave- and trim-regulating wings or hydrofoils that operate in two distinctly different states, a hydrostatically stable lower speed state with a positive metacenter height (+ GM) and with the center hull element and at least one of the side hull elements submerged, and a hydrostatically unstable higher speed state with a negative metacenter height (- GM) with the center hull element partially lifted, partially submerged, while the side hull elements are partially or completely out of the water, in the said vessel is dynamic stabilized using the foil system, and consisting of

a center hull element with an integrated rigid deck structure which in the transverse direction extends beyond the width of the center hull element, and where the underside of said deck structure, defined as the wet deck, lies above the waterline when the vessel is at rest in an intact state, and at an increasing height above the mean waterline when the vessel's forward speed is significantly increased,

said vessel has a ratio between the largest width of the frame above the waterline and the largest width of the frame on the center hull element measured on a waterline that represents an arbitrary straight-flowing condition of at least 2,

said center hull element has a ratio between greatest length in waterline

and greatest width in the waterline in an arbitrary straight-flowing state of at least 6,

said central hull element has a rectangular, U- or trapezoid-like transom shape below wet deck level in its aft part, which gradually transitions to a U-, V- and Y-shape closer to the bow, possibly a combination of these,

said vessel is provided with at least one set of side hull elements arranged so that a set consists of a side hull element placed on each side of the vessel's longship centreline, integrated to the underside of the wet deck, and with a depth that is less, possibly significantly less, than the depth of the center hull element, so that the ratio between the depth of the side hull elements and the depth of the center hull element is less than 0.7, where the depth is measured from the lower continuous deck running from the stern to the front of the vessel, to the lowest part of the bottom of said hull elements,

said side hull elements are in a preferred embodiment located wholly or partly within the width extent of the lowest continuous deck defined above,

said side hull elements are in a preferred embodiment positioned so that a

greater part lies aft of the vessel's longship's center of gravity,

said side hull elements are in a preferred embodiment positioned in such a way in the longship direction that their aft ends lie aft of the aft end of the center hull element,

said side hull elements are in a preferred embodiment arranged so that they are parallel to the vessel's longship centerline, or at a smaller angle directed inward or outward, and that said sidehull elements on both sides are arranged symmetrically around the vessel's longship centerline,

said side hull elements can, preferably on larger vessels, be placed so that one is placed in front of the other on each side in the longship direction, so that the center of gravity of the longship of the vessel comes between the aft end of the aft side hull elements and the bow of the forward side hull elements,

the wet deck extends in the longship direction at least from the upper and forward part of the bow on the side hull elements to the aft end of the center hull element, and in the longship direction has an arc shape with the end points placed at a higher level than at arbitrary points along the bow, or is in its entirety, or parts thereof, horizontal or at an angle to the horizontal plane, where the aft end is at a higher level than a point on the intermediate wet deck plane, possibly with a combination of an arc-shaped middle part and angularly oriented fore and aft parts,

said wet deck is horizontal in the transom direction or oriented at an angle so that a point on said wet deck farthest from the vessel's center line is at the same level, or at a higher level, than a point on said wet deck closer to said center line,

In a preferred embodiment, said hybrid marine vessel further includes an arrangement which constitutes a set of fully submerged primary hydrodynamic wing or hydrofoil, where the total transverse span of said hydrofoil arrangement corresponds to at least 50%, preferably close to 100%, of the vessel's greatest width, and where said hydrofoil is located close to the vessel's longship's center of gravity, or more precisely slightly forward of said point, attached to the center hull element, the wet deck and the side hull elements, possibly to parts of the wet deck or the deck structure that extends beyond said side hull element, or to any of these structural elements, depending on said hydrofoil's transom span, by means of at least two vertical and/or inclined struts which transmit the hydrodynamic lifting force ul the vessel, normally an upward force, and where at least one, preferably several, remotely controlled flaps are arranged on each side of the vessel's centerline integrated to the following edge of hydrofoil spanned, and which provides the necessary hydrodynamic stability by exerting an adjustable transom righting moment about the vessel's centerline when the vessel moves forward at higher speed with the side hull elements partially submerged or completely above the centerline of the waterline

In another preferred embodiment, said hybrid marine vessel includes an arrangement consisting of at least one fully submerged secondary hydrodynamic wing or hydrofoil, where the total transom span of said hydrofoil arrangement is less than 50% of the vessel's greatest width, and where a set of said secondary hydrofoil device is located at a greater distance behind the center of gravity of the vessel's longship, attached to the center hull element and / or the wet deck by means of at least one support for each set of hydrofoils that transmits the hydrodynamic force to the vessel, and where at least one remotely controlled flap for each set of hydrofoils is integrated to the following edge which provides the necessary trim regulating moment about the vessel's longship's center of buoyancy by exerting an adjustable longship's righting moment when the vessel moves forward at higher speed

Figures

The present invention is explained in more detail with reference to the attached figures, where;

figure 1 shows the vessel according to the invention, seen from the side;

figure 2 shows the vessel according to figure 1 at a midship section through the primary foil, and where the center hull element, wet deck and side hull elements are shown;

figure 3 shows a transom section in the stern, where the waterline (WL-1) at a higher speed condition, the waterline (WL-2) at a lower speed condition, vertical center of gravity (VCG) and metacenter point (M) at a lower speed condition and at a higher speed state (Ml);

figures 4a-4d show possible transom sections in the stern for center hulls

the element below wet deck level;

figure 4e-4m shows possible transom sections in the foredeck for the center hull element

below wet tire level;

figure 5 shows a vessel according to the invention seen from behind, and where the adjustable side hull elements are indicated;

figure 6 shows in a transom section the details of the floating elements which are adjustable in height and integrated into the side hull elements of a vessel according to the invention, and where the mode of operation is indicated;

figures 7a-7g illustrate the operation of the water ballast system;

figure 8 illustrates in plan a larger vessel with two sets of primary hydrofoils and

a double set of side hull elements;

figure 9 shows a transom section of a vessel equipped with a surface cutter

primary foil system;

figure 10 shows in a plan a fully submerged primary foil system, where the leading and trailing edge, chord length (CL) and adjustable flaps are indicated;

Figure 1 shows the profile of the vessel (1) with the center hull element (2) and the side hull elements (3). Below the vessel are shown the primary hydrofoil (4) system and vertical supports (11) as well as the secondary hydrofoil (5) system.

As described, an arrangement has been placed which constitutes a primary hydrodynamic wing or hydrofoil (4) which is placed between the center hull element (2) and the side hull elements (3) and which provides a greater hydrodynamic lifting force, resulting in a reduced draft and reduced wet liquid surface, while providing dynamic stability through a surface cutting foil system (6), as shown in Figure 9, or preferably a fully submerged foil system (4) attached to vertical supports (11) as shown in Figure 2, with a fully adjustable hydrofoil- buckle, or preferably adjustable flaps (27) integrated along the following edge (29) of said foil buckle (4). At a speed of 45 knots, the hydrodynamic lift provided by the foil system can achieve values corresponding to 20 - 90% of the light ship's displacement, depending on the size of the foil system and the vessel's displacement. As a result of this, the vessel will be lifted sufficiently into the water for the side hull elements to come completely or partially clear of the waterline.

This gives the vessel a great advantage in terms of hydrodynamic resistance compared to a traditional catamaran, which may be lifted accordingly. The reason for this is that the wet liquid surface on the center hull element according to the invention is smaller than the combined wet liquid surface on the catamaran's two hulls when the total displacement is the same. This fact, together with the effect of the foil-generated lift, contributes to a significant reduction of wet liquid surface area. Thus, it leads to a significant reduction of frictional resistance, which makes the concept exceptionally suitable as a fast-moving transport platform.

In contrast to traditional catamarans which are characterized by a high metacenter height (GM), and which results in high hydrostatic stability, or roll stiffness, the vessel according to the invention has lower hydrostatic stability at smaller angles of heel when it is at rest on the water. With increasing speed and foil-generated lift, the hydrostatic stability is further reduced. When the speed and lift are high enough, and the side hulls come clear of the waterline, the vessel will, according to the invention, enter a completely hydrostatically unstable state. Such a condition is characterized by negative metacenter height (-GM), which is generally defined as the vertical distance between the vessel's vertical center of gravity (VCG) and an imaginary metacentric point (M) on an imaginary vertical line through the vessel's centerline. At small bank angles, said vertical line will cross itself at a given point, normally above the vertical center of gravity (VCG). The higher the metacenter point is above said point, the higher the hydrostatic stability and the metacenter height (+GM) will be. An unstable vessel is therefore generally associated with a low, or negative metacenter height (-GM), which means that the metacenter point is below the vessel's vertical center of gravity (VCG).

Figure 4 shows, as indicated above, different geometric shapes of the center hull element which are examples of labile or unstable hull shapes on the indicated waterline (WL-1).

The first line of hull shapes as shown in figure 4, indicated a-d, shows four possible cross-ship shapes of the center hull element below the wet deck level in the stern. As indicated, it can consist of the fundamentally different rectangular, U-, or trapezoid-like shapes that gradually transition to a U-, V-, and Y-shape in a position further ahead. To the right of the figure, the different reference levels are indicated, namely; waterline (WL-1), wet deck level (8) and main deck level (7).

The other variants in Figure 4, e-m, show possible transom shapes in the front part of the center hull element below the main deck level (7). As indicated, these can consist of the fundamentally different V-, U-, or Y-shapes, or a combination of these. The operation of the dynamic stability as applied to the vessel according to the invention can basically be compared to the principles that are applied to modern combat aircraft. As is known, these types of aircraft are aerodynamically unstable, and thus cannot be controlled manually in contrast to conventional stable aircraft which are controlled by the pilot. Consequently, they are computer-controlled in a fundamentally identical manner to the vessel according to the invention. Naturally, they are statically stable while resting on their wheels on the ground, in a similar way to current vessels when at rest on the water or moving at slow speed. A more down-to-earth example is the bicycle, which is also statically unstable and cannot balance unless it is affected by a righting moment.

A statically unstable state combined with an active dynamic stabilizing effect, brought about through adjustable flaps on the foil system, is very advantageous in terms of achieving high comfort. The external excitation forces, represented by wave action on the hull, are naturally much smaller for a hull according to the invention and characterized by the wood negative metacenter height (-GM), in contrast to a traditional catamaran characterized by the wood high positive metacenter height (+GM). In particular, this is the case with transverse waves that cause rocking motions. As a result, this will mean that the vessel according to the invention will exhibit limited or no swaying movements, depending on the wave condition, while said catamaran cannot avoid this, even if it were to be equipped with a similar foil system.

Since only the center hull element is submerged, which typically has a considerably smaller waterline area than a catamaran or a traditional monohull vessel, the vertical heave movements are also reduced. These movements are further reduced due to the combination of passive and active damping produced by the large primary foil located close to the vessel's longship center of gravity (LCG), as indicated in Figure 1.

In a normal operating condition, where the speed will typically be 40-50 knots, the vessel will have a dynamic stability margin against swaying in side waves that can be compared to a Foilcat design that has been lifted completely clear of the water. This is because the side hull elements have considerably less displacement compared to the hulls on the aforementioned Foilcat. With regard to pitching movements, the secondary foil, or trimfoil, placed aft or forward will give a significant dampening effect on pitching movements. According to the invention, this gives the vessel unique sea characteristics.

When the vessel moves forward at a lower speed, or is at rest, the lifting force from the foil system is reduced, or ceases. Thus, the draft will increase and both side hull elements (3) will be submerged, as indicated by the waterline (WL-2) in Figures 1 and 3. Thus, the side hull elements will provide the necessary hydrostatic stability.

A method for adjusting the side hull elements is shown in figures 5 and 6. The adjustment of the side hull elements (3) can in principle take place in any technically feasible way, for example by using suitable floating elements (21) which are forced out of its normal stowed space (22) within the side hull element by injecting a medium into a piston device which pushes said element down until it is sufficiently submerged in the water, as indicated in Figure 5. In this way the hydrostatically unstable center hull element can be stabilized , and the immersion of the floating elements can be continuously adjusted, even when the vessel is operated without a stabilizing foil system.

Another method consists of the floating elements that are integrated into the side hull elements being held in a lower position at a given depth or displacement when the vessel moves forward at a lower speed, or is at rest on the water. When the speed is increased and the hydrofoil system provides the necessary dynamic stability, said floating element can be temporarily lifted so that the desired clearance to the waterline is achieved. Such an arrangement can consist of floating elements (21) which are connected to the overlying wet deck (8) by means of a number of pneumatic or hydraulic actuators (23) placed between them (8,21) in addition to an airtight flexible membrane (24) attached to said adjustable floating elements and overlying wet deck. The actuators (23) can be connected to a common or individual pressure accumulator which is provided with a necessary permanent air pressure so that the actuators and the adjustable floating elements are kept in a permanent lower position, limited by the flexible membrane (24) which completely encloses said element and the internal placed the actuators. Elevation of the floating elements is provided by applying a negative pressure to the internal volume (22) within the flexible membrane using electrically driven vacuum pumps. Thereby, the relatively large internal area will exert a sufficiently large lifting force which overcomes the downward vertical forces generated by the pressure from the hydraulic or pneumatic actuators (23), so that said actuators are pressed together, which results in the floating elements being lifted to a temporary upper position . The electric vacuum pumps can be started manually from the bridge, while the control signals that disconnect said pumps can come from the vessel's permanent electrical monitoring system, such as speed log or inclinometer. This will ensure that the vacuum pumps are automatically disconnected in a certain state or situation, e.g. at a given maximum bank angle or minimum speed. The floating elements will then automatically be lowered back to their lower normal position. The downside of this method is that it is relatively complicated and expensive. For smaller vessels, such as 30-60 m, this will result in a relatively large increase in weight. For larger vessels, however, this will not necessarily be the case since it can actually reduce weight, depending on the vessel's length and wet deck level above the waterline. The advantage is that it can reduce the draft of the side hull elements when the vessel is operated at a higher speed, which in turn can reduce the possibility of these interfering with the waves. Compared to the water ballasting method described below, it will reduce the maximum draft as well as drag at lower speed since the method does not result in increased displacement at lower speed.

Another method is for the vessel to be provided with a separate water ballast tank (15), as shown in figures 1 and 7, structurally integrated in the bottom of the center hull element (2), and placed at a distance forward of the vessel's stern, preferably aft of the center of gravity of the longship ( LCG). In the aft part of the tank there is an opening (16) with a suitable design, and at a given distance aft of a vertical step (17) in the bottom plate. When the vessel is at rest, and with a suitable speed below a given value, the water will flow into the tank as illustrated in figure 7 b. The maximum speed at which this will take place is given by the lengthwise extent of the opening (16) and the vertical distance between the step (17) at the front of the opening and the toe (18) at the aft edge of the opening, as well as the static pressure head of the water. When the speed is above this value, the water flow will be separated by the vertical step (17). With increasing speed, the direction of the water flow will move more towards the horizontal plane, until at a given speed it no longer hits the toe of the inclined aft part of the opening, but passes under it, as illustrated in Figure 7 a. In this condition, the ballast tank will no longer take in water, but is gradually emptied using the so-called ejector principle until it is completely empty. At a given lower speed, the water flow will again hit the toe, be separated and lead into the tank until it is filled. The tank is provided with a pipe (25) for venting to atmosphere to avoid vacuum and overpressure in the tank.

The above-mentioned five-pass method presupposes a certain degree of ideal conditions, where the static pressure head, given by the vessel's draft, is approximately constant. This is of course not always the case as it is affected by load condition, trim, foil generated lift and waves. To remedy the problem, an adjustable wedge-shaped shoe (19) can be placed in the aft part of the opening, as shown in figure 7 d. This is hinged in the aft part at point (27) so that its angular position can be freely adjusted up and down. The bottom of the shoe is preferably designed so that it is arched in the longitudinal direction. The toe of the shoe is wedge-shaped so that it will easily separate the flow of water. When the vessel is at rest, or moving forward below a given speed, the shoe will point downwards in the vertical plane as illustrated by the dashed lines in figure 7 d, so that the toe of the shoe sticks sufficiently deep in relation to the lower part of the step (17) to ensure that it "shovels" water. Depending on the toe's vertical level in relation to said lower part of the step, the angle of the hinged shoe at a given speed will change by itself when the water flow no longer hits the toe. At this moment, "shoveling" of water ceases, and the tank gradually empties. In this condition, the shoe will plan on the surface of the water flow due to the planing forces and the vertical planing about the hinges of the shoe, provided it is freely stored. As long as the speed is above a given value, the shoe's angle will regulate itself and adapt to the minor variations on the surface of the water flow that are affected by trim and waves, without the toe touching the water flow. When the speed is again reduced below a given value, the water flow will again hit the toe, be separated and "shoveled" into the tank. By connecting a remote-controlled hydraulic cylinder to the shoe, a greater degree of control over the shoe's angular position can be achieved, and thus the tank will be able to be filled and drained more independently of the vessel's speed (V).

A preferred arrangement in relation to the above alternatives is the arrangement as shown in Figure 7 f-g. Here the hinged shoe has been removed and replaced with a permanent toe as first described However, a hinged plate (20) has been placed in front of the opening. A remote-controlled actuator device (26) which is controlled from the bridge is attached to the plate so that it can be tilted vertically around the hinge (27) placed at the front. When the plate is in the lower position, the water flow will separate at the aft edge of the plate and pass under the toe, depending on the speed and the tilt angle of the plate. When the plate is tilted slightly upwards, the water flow will follow the plate, depending on the tilt angle and speed (V), and is thereby directed into the tank. This method is safer and more advantageous from an operational perspective. In a similar way to the remote-controlled shoe option, the filling and emptying of the tank can be controlled more independently of the vessel's speed and trim, but the latter option will presumably be less prone to damage in operation. Depending on the volume of the tank and the longship's position, the aforementioned rapid ballasting system can be used to give the side hull elements the required degree of immersion, which means that the vessel will have a rapid transition from dynamic to static stability. Naturally, this transition can also be assisted by using the trim foil. This method is advantageous because of its operational simplicity

Claims (12)

1. A high-speed hybrid marine vessel (1) equipped with hydrodynamic lift-generating, yaw, pitch, and trim control wings or hydrofoils (4,5) operating in two distinctly different states, a hydrostatically stable lower speed state with a positive metacenter height (+ GM ) with the center hull element (2) and at least one of the side hull elements (3) submerged, and in a hydrostatically unstable higher speed condition with a negative metacenter height (- GM) with the center hull element (2) partially raised, partially submerged, and the side hull elements partially or completely out of the water , in which the vessel is dynamically stabilized using said hydrofoil system, characterized by the vessel (1) consists of a center hull element (2) with an integrated rigid deck structure which in the transverse direction extends beyond the width of the center hull element (2), and where the underside of the deck structure, defined as the wet deck (8), lies above the waterline (WL-2 ) when the vessel is at rest in an intact state, the vessel (1) has a ratio between the largest width of the frame above the waterline and the largest width of the frame on the center hull element (2) on a waterline (WL-1, WL-2) that represents an arbitrary straight-floating condition of at least 2, the center hull element (2) has a ratio between greatest length in the waterline and greatest width in the waterline in an arbitrary straight-flowing condition of at least 6, the center hull element (2) has a transom shape below the wet deck (8) level which gradually transitions to a U-, V- and Y-shape closer to the bow, or a combination of these, the vessel (1) is provided with at least one set of side hull elements (3) arranged so that a set consists of a side hull element located on each side of the vessel's longship centerline, integrated to the underside of the wet deck level (8), and with a depth that is less than the depth on the center hull element (2), the side hull elements (3) are positioned in the longship direction so that a larger part lies aft of the vessel's longship center of gravity, the wet deck (8) extends in the longship direction at least from the upper and forward part of the bow (30) on the side hull elements to the aft end (14) of the center hull element (2), said wings or hydrofoils (4, 5) are positioned so that the joint point for hydrodynamic lift is located at or near the center of gravity of the vessel's longship, said wings or hydrofoils (4,5) provide a dynamic lifting force at maximum speed corresponding to at least 20% of the vessel's lightest weight 2. High-speed hybrid marine vessel (1) according to claim 1, characterized by an arrangement which constitutes a fully submerged primary hydrodynamic wing or hydrofoil (4) where the total transom span of said hydrofoil device corresponds to at least SO% of the vessel's greatest width, located close to the vessel's longship center of gravity , and fixed by means of at least two vertical and/or inclined struts (11) which transmit the hydrodynamic lifting force to the vessel, and where at least one remotely controlled flap (27) is arranged on each side of the vessel's centerline integrated to the following edge of the hydrofoil span ( 4) which provides the necessary hydrodynamic stability by & exerting an adjustable transverse righting moment about the vessel's centerline (9) when the vessel moves forward at higher speed 3. High-speed hybrid marine vessel (1) according to crawl and 2, characterized by an arrangement constituting a set of fully submerged secondary hydrodynamic wing or hydrofoil (S) placed on the center hull element (2) at a greater distance behind the center of gravity of the longship of the vessel, where the total transverse span of said set corresponds to less than 50% of the vessel's greatest width, attached to the center hull element and/or the wet deck (8) by means of at least one support (11) for each said set which transfers the hydrodynamic force to the vessel, and where at least one remote-controlled flap (27) is integrated into the aft part of said set and which provides the necessary trim-regulating moment about the vessel's longship's center of buoyancy by exerting an adjustable longship's righting moment when the vessel moves forward at higher speed 4. High-speed hybrid marine vessel (1) according to claims 1 and 2, characterized by an arrangement which constitutes two sets of fully submerged secondary hydrodynamic wing or hydrofoil (5), where both sets are placed on the center hull element (2), where one of said sets is placed at a greater distance behind the vessel's longship's center of gravity, while the other is placed at a greater distance forward of said center of gravity, where the total transom span for each of said sets corresponds to less than SO% of the vessel's greatest width, the center hull element and / or wet deck attached ( 8) by means of at least one support (11) for each said set which transfers the hydrodynamic force to the vessel, and where at least one remote-controlled flap (27) is integrated to the aft part of said set and which provides the necessary trim regulating moment about the vessel's longship center of buoyancy by exerting an adjustable longship righting moment when the vessel moves forward at higher speed 5. High-speed hybrid marine vessel (1) according to crawling, characterized by an arrangement comprising two sets of fully submerged primary hydrodynamic wings or hydrofoils (4) where the total transverse span of each set corresponds to at least 50% of the largest width of the vessel, where one of said set is placed at a greater distance in front of the vessel's longship's center of gravity, while the other is placed at a greater distance behind said center of gravity, fixed by means of at least two vertical and/or inclined struts (11) per set that transmit the hydrodynamic forces to the vessel , and where at least one remotely controlled adjustable flap (27) per set is arranged on each side of the vessel's centreline, where said flap arrangement is integrated to the aft part of the aft hydrofoil span (4) while the other is integrated to the aft part of the front hydrofoil span, and where the flap arrangement provides the necessary hydrodynamic stability and trim damping by exerting an adjustable transom and longitudinal re th moment when the vessel moves forward at a higher speed 6. High-speed hybrid marine vessel (1) according to claim 1, characterized by an arrangement consisting of several sets of fully submerged primary hydrodynamic wings or hydrofoils (4), attached to the vessel by means of vertical and/or inclined struts (11). 7. High-speed hybrid marine vessel (1) according to claim 1, characterized by an arrangement consisting of one or more sets of hydrodynamically self-stabilizing surface-cutting wings or hydrofoils (6), attached to the vessel by means of vertical and/or inclined struts (11). 8. High-speed hybrid marine vessel (1) according to claims 1-7, characterized in that the side hull elements (3) consist of structurally integrated or independently attached elements located below the wet deck level (8) 9. High-speed hybrid marine vessel (1) according to claims 1-8, characterized by separate side hull elements (21) which are independently adjustable in height over the entire length of the side hull elements, or over a larger part of their length 10. Fast-moving hybrid marine vessel (1) according to claims 1 -9, characterized in that the side hull elements (3) on larger vessels are arranged so that one is placed in front of the other on each side in the longship direction so that the center of gravity of the longship of the vessel lies between the aft end of the the aft side hull elements and the bow of the forward side hull elements 11. High-speed hybrid marine vessel (1) according to claims 1-9, characterized in that the center hull element (2) is provided with one or more water ballast tanks (15) for rapid emptying and filling of water using (16,17,18,25 ) 12. High-speed hybrid marine vessel (1) according to requirements 1-10, characterized by the water ballast tank (15) integrated in the submerged part of the center hull element (2) provided with a permanent opening (16) at the bottom of said hull element and located in front of the stern end ( 14) on said hull element, for using the effect of the surrounding water's static pressure head and / or dynamic pressure head for rapid filling of the tank when the vessel is at rest or moving forward, and which utilizes the effect of the dynamic pressure head of the water flow that passes under the opening to to drain the water ballast at a suitable speed by means of a vertical step (17) in the bottom plate and a structurally integrated wedge-shaped toe (18) in the aft part of the opening, alternatively a self-regulating or remotely controlled separately hinged shoe (19) placed in the aft part of the opening , or a remote-controlled adjustable plate (20) placed in the front part of the opening and hinged at point (27) behind the vertical step.