Vessel with an improved hull.

The present invention concerns a vessel with an improved hull.

In particular, the present invention concerns a vessel with an improved hull, whereby the hull consists of a central hull part and two lateral hull parts provided on either side on the central hull part.

Such vessels are widely known, for example in the form of speedboats, yachts, commercial vessels or the like.

The hulls of these known vessels have evolved over the years from hulls with an extremely deep V-shape into designs with several hull parts.

The supporting part of the hull, with which the vessel is carried by the water, is hereby kept as small as possible while sailing, such that the friction between the vessel and the water is restricted as much as possible.

A first disadvantage of such known vessels, however, is that, in order to lift the vessel from the water so as to be able to make the vessel plane on such a limited bearing surface, an enormous amount of energy is consumed, which energy

is simply wasted.

Another disadvantage of such known vessels is that they cause huge waves, which may be very annoying to fishermen for example, which may destroy the plant and animal life in the water or damage the quay.

Another disadvantage of these known vessels is that the supporting part of the hull is usually situated far in the back of the vessel while sailing, whereas the centre of gravity of the vessel is situated more in the centre of the vessel, which results in an unstable situation.

Consequently, the vessel tends to constantly penetrate in the water with its BOW, as a result, of which a rocking motion is created and the vessel is strongly slowed ^' down by the hydrodynamic resistance at each downward movement, reducing the vessel's performance and increasing the vessel's fuel consumption.

Moreover, as the speed of these known vessels increases, the vessel's instability increases, as the supporting part of the hull is situated more and more to the back, such that the distance between the vessel' s centre of gravity and said supporting part of the hull increases further.

Other known vessels are for example hydrofoil crafts.

Such hydrofoil crafts consist of a hull on which are provided hydrofoil struts under the water line, comparable to the wings of aeroplanes, which hydrofoil

struts lift the vessel from the water as soon as the vessel has a sufficiently high speed.

These known hydrofoil crafts are advantageous in that lifting the vessel out of the water requires far less energy than with the ordinary, conventional speedboats, whereas very high speeds can be realised as well.

Moreover, they lie far more stably in the water, as hydrofoil struts are usually fixed to the BOW as well as to the stern.

However, a disadvantage of these known hydrofoil crafts is that they that have a deep draught, as long as they are not planing, which may be a problem when slowly entering the harbour.

An additional disadvantage of these known hydrofoil crafts is that they cannot sail on a rough sea.

Further, they are very fragile and can be easily damaged. Moreover, they have a peculiar look.

The present invention aims to remedy one or several of the above-mentioned and other disadvantages.

To this end, the invention concerns a vessel with an improved hull, whereby the hull consists of a central hull part and two lateral hull parts provided on either side of the central hull part and whereby, when the vessel is lying in the water, the supporting part of the central hull part extends by a certain length over the supporting part of the

lateral hull parts in the axial direction of the vessel, and the different hull parts are placed at a certain angle of heel in relation to the water line when the boat is at rest.

An advantage of such a vessel according to the invention is that, thanks to the mutual arrangement of the hull parts in relation to each other as well as in relation to the water line, the vessel lies very stably in the water, also when sailing at high speed.

Another advantage of such a vessel according to the invention is that the vessel requires far less energy to gain speed and that it can be optimally lifted out of the water.

An additional advantage is that such a vessel can sail at much higher speeds, as the resistance is very small thanks to the optimal lift.

The above-mentioned angle of heel of the hull parts in relation to the water line is preferably such that the vessel undergoes an upward force while sailing.

This will be the case, for example, when the inclination of the supporting parts of the hull parts is at least partly directed upward towards the BOW.

The above-mentioned upward force is due to the pressure exerted by the water on the aforesaid inclinations of the hull parts while the boat is sailing, which force also has a vertical component, which offers the advantage that a vessel according to this embodiment can be very easily

lifted from the water so as to plane, such that energy is saved or less engine power is required.

According to another preferred embodiment of a vessel according to the invention, the above-mentioned supporting hull parts are mainly situated in a triangle while sailing, whereby the centre of gravity of the vessel is situated within the above-mentioned triangle, seen from above.

Such an embodiment of a vessel according to the invention has a particularly good stability on the water, comparable to the stability of the known hydrofoil crafts.

Moreover, such a vessel according to the invention is far more compact, it has a shallower draught and it is less liable to damage than the known hydrofoil crafts.

On the other hand, such a vessel according to the present embodiment is no longer subject to the aforesaid rocking motion, as is known from the other conventional vessels.

In order to better explain the characteristics of the invention, a preferred embodiment of a vessel with an improved hull according to the invention is described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:

figures 1 tot 4 represent a vessel according to the invention in which the different hull parts are indicated, in a side-view, bottom view, top view and rear view respectively;

figures 5 to 8 and 9 to 12 represent the vessel, analogous to figures 1 to 4, with an indication of the water line when the vessel is at rest and makes speed respectively; figures 13 to 16 represent cross sections according to lines III-III, IV-IV, V-V and VI-VI from figures 5 and 6 respectively, with an indication of the water line when the vessel is at rest; and figures 17 to 20, analogous to figures 13 to 16, represent the condition when the vessel makes speed.

The vessel 1 according to the invention as represented in figures 1 to 20 is made with an improved hull 2, whereby this hull 2 consists of a central hull part 3 and two lateral hull parts 4 and 5 provided on either side of the central hull part 3.

Initially, the improvement of the hull 2 of the vessel 1 according to the invention consists in that, when the vessel 1 is situated in the water, as represented in figures 5 to 12, the supporting part 6 of the central hull part 3 extends from the supporting parts 7 and 8 of the lateral hull parts 4 and 5 by a certain length L or L' in the axial direction AA ¹ of the vessel 1.

Moreover, according to the invention, the different supporting parts 6 to 8 of the hull parts 3 to 5 are positioned at a certain angle of heel B in relation to the water line W when the vessel 1 is at rest.

This angle of heel B depends on the application and may thus

vary depending on whether the vessel in question is a fast pleasure boat, a fast vessel for commercial transport, a speedboat or another type of vessel, whereby the angle B is such that, while sailing, the vessel 1 undergoes an upward force.

Moreover, the angle of heel B of the central hull part 3 must not necessarily be the same as the angle of heel B of the lateral hull parts 4 and 5.

In order to obtain an upward force, it is sufficient if the angle of heel B of the supporting parts 6 to 8 of the hull parts 3 to 5 is directed at least partly upward towards to the BOW 10 of the vessel 1, whereby this part of the central hull part 3 is preferably positioned towards the front in the axial direction AA' in relation to the other supporting parts 7 and 8 of the lateral hull parts 4 and 5.

This angle of heel B is further selected such that it corresponds practically to the gradient which the hull of a conventional vessel, such as a speedboat or the like, assumes when it is partly lifted out of the water as it gains speed, such that it is able to plane.

In the given example, the central hull part 3 extends up to the stern 9 of the vessel 1.

Moreover, a part 11 of the central hull part 3, which is situated between the two lateral hull parts 4 and 5, has an angle of heel C which is directed upward towards the stern 9 of the vessel 1.

Optionally,, this part 11 which is directed upward towards the stern 9, can moreover be provided with a hinge 12 around which the rear part 13 of the part 11 may hinge.

In other words, the moving part 13 can be adjusted in height in relation to the rest of the hull 2, such that what is called a trimming tab is obtained.

The hull parts 3 to 5 may be formed as individual parts or they may melt into one another, as illustrated in the cross sections of figures 13 to 20, as a single integrated hull 2.

The shape of the central hull part 3 of the vessel 1, seen in cross section at right angles to the axial direction AA" , preferably has a V-shaped profile 14.

The lateral hull parts 4 and 5 preferably have a V-shaped profile 15 as well, seen in cross section at right angles to the axial direction AA', which is turned somewhat to the centre of the vessel 1, however.

The principle of the invention is as follows.

The position of rest of the vessel 1 is illustrated in figures 5 to 8 and 13 to 16 by means of the water line W, whereby the supporting part 6 to 8 extends over a height H of the vessel 1.

When the vessel 1 is run up to speed from the above-mentioned position of rest, for example by means of a motor, the

resistance of the water to the supporting parts 6 to 8 of the hull parts 3 to 5 will exert an upward force on the vessel 1, as the hull parts 3 to 5 are formed with a certain angle of heel B in relation to the water line W.

Thus, thanks to this upward force, the vessel 1 will be partly lifted out of the water into a position, as represented in figures 9 to 12 and 17 to 20, in which it is clearly visible that the height H' at which the vessel 1 lies in the water in relation to the water line W , has been reduced. -

This condition of the vessel 1 is also called the planing of the vessel 1.

Thanks to the shape of the vessel 1 according to the invention, the power which is required to partly lift the vessel 1 out of the water will be much smaller than with the known vessels.

It should be noted that, while planing, the vessel 1 is partly lifted out of the water, whereby the vessel 1, as opposed to the known speedboats, always retains a horizontal position.

This offers as an extra advantage that the view in front of the bow of the vessel 1 is always optimal.

As represented in the bottom view of figure 10, the above-mentioned supporting parts 6 to 8 of the hull parts 3 are necessarily situated in a triangle D while sailing.

It is made sure, according to the invention, that the centre of gravity G of the vessel 1 is always situated within this triangle D, seen from above.

As a result, the vessel 1 will always assume a very stable position while sailing, such that the vessel 1 will not be slowed down so much by the known rocking motions arising in the known conventional vessels.

As the vessel 1 is made with a central hull part 3 provided with a V-shaped profile 14 and with lateral hull parts 4 and 5 which have a V-shaped transverse profile 15 as well, which is tilted somewhat towards the centre of the vessel 1, whereby the lateral hull parts 4 and 5, together with the central hull part 3 and the water, enclose a space 16 which narrows towards the rear, this makes sure that, while sailing, due to the speed of the vessel 1, the air is pushed under the vessel 1 at the above-mentioned space 16, such that an air film is created between one or several hull parts 3 to 5 and the water.

In this air film, the air pressure is higher, such that an upward force is exerted on the vessel 1, and the vessel 1 undergoes an extra lift.

Thanks to the shallower draught, the vessel 1 has to displace less water while sailing, which of course has a positive effect on the energy consumption and which makes it easier to gain high speeds.

Moreover, the vessel 1 undergoes less frictional resistance while sailing, as the air film provides for a

sort of lubrication between the wall of the vessel 1 and the water.

Further, this phenomenon helps to reduce shocks while sailing, for example due to the beating of the waves or the like.

Further, the V-shaped transverse profile 15 of the lateral hull parts 4 and 5 is tilted somewhat to the centre of the vessel 1, as the supporting parts 7 and 8 of the lateral hull parts 4 and 5 are turned somewhat to the inside of the vessel 1 in this manner.

An advantageous consequence thereof is that the water displacement is directed to the inside as well, and not to the outside, which again produces a push-up effect.

Another major advantage of a vessel 1 according to the invention is that, by providing the central hull part 3 with an upward directed angle of heel C towards the stern, an interaction is created between the waves produced by the central hull part 3, which surge as of the centre line of the vessel 1, and the waves produced by the lateral hull parts 4 and 5, which surge as of the lateral hull parts 4 and 5 to the centre line, whereby this interaction is optimised such during the design stage that both waves practically neutralize one another when the vessel makes speed.

Thus, the net produced surge will be much smaller compared to the surge caused by the conventional known vessels, which

again has a positive effect on the performance of the vessel 1.

Further, the angle of heel C is such that the part 11 of the central hull part 3 comes as close as possible to the water surface, without the part 11 ending up in the water while sailing, however.

This takes into account that a waterway 17 is created by the part 6 of the central part 3 which is situated more to the front and which lies deeper in the water, which waterway 17 is represented by means of a dashed line in figure 19.

The situation can be compared to what happens with a wing profile of an aeroplane.

Thus, a pressure is built up between the water surface and the rear part 11 of the central hull part 3, which again makes sure that the vessel undergoes an upward force or lift.

It also provides for a good air lubrication.

By moreover providing the vessel 1 with a moving part 13 which is hinge-mounted in relation to the rear part 11 of the central hull part 3, which part 13 can be set in the right position for example by the skipper of the vessel 1 or by an automatic control mechanism, it is possible to optimize the pressure build-up under the rear part 11 of the vessel 1 and thus to optimize the lift 10 exerted on the vessel while sailing, for example ' as a function of the speed .

It is also clear that the principle of the invention makes it possible to design the vessel 1 such that it can compete, as far as looks are concerned, with the trendy designs of the known speedboats and motorboats , which is not true for the known hydrofoil crafts .

Of course, many forms of the vessels 1 according to the invention are possible, whereby it is each time important, taking into account the distribution of weight in the ve s s el 1 and the above -des cribed principle s , to e st abl i sh by experiment what form can be best given to the ves s el 1 , depending on the f ield of application .

Parameters which may certainly vary are, among others :

the above-mentioned angles of heel B and C; the length L or L ' by which the supporting part 6 of the central hull part 3 extends from the other supporting parts 7 and 8 ; the particular shape of the cross sections, for example to optimize the flow of air; the position of the centre of gravity G; etcetera.

The angles of heel B and C are generally smaller when a vessel is concerned which is designed to move large masses at a relatively low speed, and vice versa, the angles of heel B and C are larger when a rather light, fast vessel is concerned.

Also the aimed speed plays a major role when determining the

angles of heel B and C.

The present invention is by no means restricted to the vessels given as an example; on the contrary, such vessels can be made according to all sorts of variants while still remaining within the scope of the invention.