Entrapment tunnel monohull optimized for waterjet and high payload

Abstract

An entrapment tunnel watercraft vessel having three hulls consists of a main hull and two amas arranged outboard of the main hull with the keels of the three hulls being parallel. The main hull is a narrow, vee hull with variable, rearwardly decreasing deadrise. The amas have very fine bows and narrow, asymmetric deep-V hulls, with nearly vertical slab outboard sides above their keels and variable reverse deadrise on their inboard sides with the reverse deadrise angles decreasing from bow to stem. The tunnels on each side of the main hull are formed by three distinct surfaces, the sides of the main hull above its chine, the reverse deadrise inboard sides of each ama upward from their keels and a ceiling surface transversely spanning the aforementioned sides and having rearwardly increasing deadrise and rearwardly decreasing width. The tunnel ceilings slopes down from the bow to a section aft of midship where the ceiling height above the keel remains essentially constant. At speed the craft generates substantial amounts of lift and positive trim, thereby reducing the forward wetted length of the immersed tunnel ceiling and the apex of the ceiling is approximately at the craft dynamic waterline. As a result the watercraft vessel has improved seakeeping, stability and weight carrying ability.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be apparent in the following detailed description of illustrative embodiments thereof when read in connection with the accompanying drawings, wherein:

FIG. 1 is an isometric view of the preferred embodiment of a watercraft vessel constructed in accordance with the present invention taken from a point below and forward of the bow.

FIG. 2 is a side elevational view of the watercraft vessel shown in FIG. 1;

FIG. 3 is bottom view of the watercraft vessel shown in FIG. 1;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 2;

FIG. 6 is a cross-sectional view taken along line C-C of FIG. 2;

FIG. 7 is a cross-sectional view taken along line D-D of FIG. 2;

FIG. 8 is a cross-sectional view taken along line E-E of FIG. 2.

FIG. 9 is a bottom perspective view of a watercraft vessel (from below, aft) of a vessel including a hull form in accordance with the present invention and showing the location of the water inlets to the vessels set drives.

FIG. 10 is a bottom view of the watercraft shown in FIG. 9; and

FIG. 11 is a rear view of the watercraft vessel of FIG. 9.

Claims

1. A watercraft comprising a center hull and a pair of side hulls respectively located on opposite sides of the center hull, said center hull having a v-form including varying deadrise from the bow to at least a predetermined point forward of the stem, and said side hulls each having inner surface portions facing the center hull having greater reverse deadrise than the deadrise of the opposing surface of the center hull.

2. A watercraft as defined in claim 1 wherein said side hulls have outboard surfaces which are substantially vertical to the water surface when the hull is at rest.

3. A watercraft as defined in claims 1 or 2 wherein said center hull has vertical surface portions facing the reverse deadrise surface portions of said outer hulls.

4. A watercraft as defined in claim 3 wherein said center hull includes a deadrise surface portion on each of its sides extending from said vertical surface and intersecting with the reverse deadrise surface portion of the outer hulls, whereby said vertical surfaces, reverse deadrise surfaces and deadrise surface portions define an air entrapment tunnel on each side of the center hull.

5. A watercraft hull as defined in claim 4 wherein the reverse deadrise decreases on said outer hulls from bow to stem.

6. A watercraft as defined in claim 5 wherein said center hull has an at rest design water line.

7. A watercraft as defined in claim 6 wherein said center hull and outer hulls each have keels below the design waterline with the keels of the outer hulls being closer to the design waterline than the keel of the center hull.

8. A watercraft as defined in claim 6 wherein the center hulls and outer hulls include aft transom portions.

9. A watercraft as defined in claim 8 wherein said deadrise portions of the center hull from said transom portion forward for approximately 35% of the length of the center hull is located below said design waterline.

10. A watercraft as defined in claim 9 wherein said center hull and outer hulls each have keels below the design waterline with the keels of the outer hulls being closer to the design waterline than the keel of the center hull.

11. A watercraft as defined in claim 6 wherein said deadrise portions of the center hull slope fore to aft.

12. A watercraft as defined in claim 6 wherein the width of said deadrise portions of the center hull decreases fore to aft.

13. A watercraft as defined in claim 6 wherein said reverse deadrise of the inner surface portions of the side hulls scope fore to aft.

14. A watercraft as defined in claim 6 wherein the width of the reverse deadrise inner surface portions of the side hulls increases from fore to aft.

15. A watercraft as defined in claim 3 wherein said center hull includes a plurality of running strakes.

16. A watercraft as defined in claim 13 wherein said running strakes run from the bow of the center hull to a predetermined point A midship.

17. A watercraft as defined in claim 3 wherein said center hull includes a chine adjacent said vertical surface portions.

18. A watercraft as defined in claim 3 wherein the center hulls and outer hulls include aft transom portions.

19. A watercraft as defined in claim 16 wherein said hulls have a bustle extension aft of said transom portions, said bustle extension including a pair of spaced facing vertical surface portions generally aligned with the aft ends of the vertical surface portions of the center hull extending vertically from the water line at which the ends of the deadrise surfaces portions terminate at said transom portions, and a horizontal ceiling portion extending between said spaced vertical portions of the bustle above the watercraft design waterline.

20. A watercraft as defined in claim 17 wherein said bustle extension has running surfaces formed thereon outboard of its spaced vertical surface portions.

21. A watercraft as defined in claim 17 wherein said running surface of the bustle extension includes a deadrise portion corresponding in size and deadrise to the deadrise surface portions of the center hull at the transom and flat surface portion outboard of its deadrise surface portions.

22. A watercraft as defined in claim 1 wherein said center hull includes a deadrise surface portion on each of its sides intersecting with the reverse deadrise surface portion of the outer hulls, to define an air entrapment tunnel on each side of the center hull.

23. A watercraft hull as defined in claim 22 wherein the width of the reverse deadrise increases on said outer hulls from bow to stern.

24. A watercraft as defined in claim 33 wherein said center hull has an at rest design water line.

25. A watercraft as defined in claim 22 wherein said center hull and outer hulls each have keels below the design waterline with the keels of the outer hulls being closer to the design waterline than the keel of the center hull.

26. A watercraft as defined in claim 22 wherein the center hulls and outer hulls include aft transom portions.

27. A watercraft as defined in claim 26 wherein said deadrise portions of the center hull from said transom portion forward for approximately 35% of the length of the center hull is located below said design waterline.

28. A watercraft as defined in claim 27 wherein said center hull and outer hulls each have keels below the design waterline with the keels of the outer hulls being closer to the design waterline than the keel of the center hull.

29. A watercraft as defined in claim 22 wherein said deadrise portions of the center hull slope fore to aft.

30. A watercraft as defined in claim 22 wherein the width of said deadrise portions of the center hull decreases fore to aft.

31. A watercraft as defined in claim 22 wherein said center hull includes a chine spaced from the keel of the hull.

32. A watercraft as defined in claim 31 wherein said center hull has vertical surface portions extending upwardly from said chines.

33. A watercraft as defined in claim 22 wherein the center hulls and outer hulls include aft transom portions.

34. A watercraft as defined in claim 33 wherein said hulls have a bustle extension aft of said transom portions, said bustle extension including a pair of spaced facing vertical surface portions generally aligned with the aft ends of the vertical surface portions of the center hull extending vertically from the water line at which the ends of the deadrise surfaces portions terminate at said transom portions, and a horizontal ceiling portion extending between said spaced vertical portions of the bustle above the watercraft design waterline.

35. A watercraft as defined in claim 34 wherein said bustle extension has running surfaces formed thereon outboard of its spaced vertical surface portions.

36. A watercraft as defined in claim 35 wherein said running surface of the bustle extension includes a deadrise portion corresponding in size and deadrise to the deadrise surface portions of the center hull at the transom and flat surface portion outboard of its deadrise surface portions.