Stepped bottom and variable frame cross section powerboat hull

Abstract

It concerns a hull made up of three (3) sections of different draught, width and design each. The front section (F) is larger than the middle (M) and the rear section (R), while the middle is larger than the rear. The hull sections are divided between them by a transverse rib ( 5 ). In the front, instead of having stabilizer fins, there are four oblong ribs ( 3 ) on each side. In the middle there are three oblong ribs ( 3 ) while in the rear there is one oblong rib ( 3 ) and two stabilizing fins ( 6 ) on each side. The advantage of this invention is the acquired capability of the powerboat to achieve higher speed, with less power and fuel economy, as there is a great reduction in friction due to the hull's design.

1 . The stepped-draught and variable limber-hole hull used in the manufacturing of all kinds of powerboats is made up of three sections (F) (M) (R), which differ in draught, width and design. The front section (F), instead of stabilizing fins, has three oblong ribs ( 3 ) on each side. The front section (F) has a sixty-nine degree (69°) V at its lowest point ( 1 ), which decreases reaching forty degrees (40°) at the point of contact ( 2 ) with the middle section of the hull (M). The middle section of the hull (M) has a smaller draught than the front. It is separated from the front with a crosscut rib ( 5 ) created by the draught difference between the front and the middle section of the hull. The middle section has three oblong ribs ( 3 ) and only one ( 1 ) stabilizer fin ( 6 ) over the first oblong rib. The middle section of the hull at its lowest point ( 7 ) has a V starting from the point of contact with front section of the hull, from forty degrees (40°) and ends at the point of contact with the rear section of the hull ( 8 ) at twenty-seven degrees (27°). The rear section of the hull (R) forms a recess compared to the middle section. It has a smaller draught than the front and middle sections and is separated from the middle section with one oblong rib ( 3 ). The rear section of the hull begins with a V of twenty-seven degrees (27°) at the point of contact with the middle section of the hull and ends at the boats mirror at an oval surface ( 9 ). The rear section has only one oblong rib ( 3 ) from each side, which is near the tail of the hull ( 9 ), while there are stabilizing fins ( 6 ) put on the imaginary line of the ribs of the hull's middle section.  
   
   
       2 . The powerboat hull is characterized according to  claim 1  by its four oblong ribs ( 3 ) on each side of its front section (F), three oblong ribs and one stabilizing fin on each side of the middle section (M) and one oblong rib ( 3 ) on each side of the rear section (R).  
   
   
       3 . The powerboat hull is characterized according to  claim 1  by the fact that its three sections are separated by two crosscut ribs ( 5 ) creating recesses. Therefore, the middle section (M) is a recess compared to the front section of the hull (E), and the rear section (R) a recess compared to the middle section of the hull.  
   
   
       4 . The powerboat hull is characterized according to  claim 1  by the fact that despite its sixty-nine degree V at its front section, the existence of oblong ribs instead of stabilizing fins gives at its upper tail the dimension of 1.75 m.  
   
   
       5 . The powerboat hull is characterized according to  claim 1  by the fact that the oblong ribs of the middle section of the hull, the stabilizing fin of its middle section and the stabilizing fins of the rear section are on an imaginary line with the oblong ribs of the front section, but they begin their stretch at a distance from the crosscut ribs that separate the hull's sections.  
   
   
       6 . The powerboat hull is characterized according to  claim 1 ,  2 ,  3  and  4  by the fact that during cruising it achieves a reduction of friction created by movement on the water's surface at a rate over 50% of the friction created by common hulls.  
   
   
       7 . The powerboat hull is characterized according to  claim 1 ,  2 ,  3 ,  4  and  5  by the fact that its front section is of larger dimensions than the other sections, creating during cruise a passage for the other sections to pass through, which because of their smaller dimensions run through the water at a higher speed and less friction.  
   
   
       8 . The powerboat hull is characterized according to  claim 1 ,  2 ,  3 ,  4 ,  5  and  6  by the fact that it is under less stress than common hulls, and this allows a lighter structure in its inner supports, so the total final weight of the boat is lighter than that of the boats that use common hulls.