MARINE VESSEL HULL WITH A LONGITUDINALLY-VENTED, PARTIAL-BEAM TRANSVERSE STEP
A marine vessel hull, and marine vessels comprising at least one such hull, comprising a non-entrapment hull having at least one partial-beam, longitudinally vented transverse step, each partial-beam, longitudinally vented transverse step comprising a transverse step with port and starboard portions that extend inwardly to an intersection with at least one longitudinal step but do not fully extend from starboard to port across the full beam of the vessel.
This application claims priority from U.S. Provisional Application Ser. No. 62/835,650, filed Apr. 18, 2019, titled MARINE VESSEL HULL WITH A LONGITUDINALLY-VENTED, PARTIAL-BEAM TRANSVERSE STEP, incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTIONVarious boat hulls designs are known in the art with advantages and disadvantages. Hulls with transverse steps have certain performance benefits and hulls with longitudinal steps generally have a softer ride and tend to be very stable.
Certain hull designs comprising a combination of transverse steps and longitudinal steps are known, including Applicant's U.S. Pat. No. 10,246,162, titled MARINE VESSEL HULL WITH A LONGITUDINALLY VENTED TRANSVERSE STEP, incorporated herein by reference in its entirety. Designs, such as those disclosed in the foregoing and as depicted in
Thus, there is a continued desire in the art to design boat hulls that provide desired or optimal performance in specific situations.
SUMMARY OF THE INVENTIONOne aspect of the invention comprises a marine vessel hull having at least one longitudinally-vented, partial-beam transverse step. Each longitudinally-vented, partial-beam, transverse step comprises at least one port forward longitudinal step portion connecting to a port transverse step portion and at least one starboard forward longitudinal step portion connecting to a starboard transverse step portion. The port transverse step portion extends to the port of the vessel from an intersection with the at least one port forward longitudinal step portion. The at least one port forward longitudinal step portion defines a longitudinal air pathway configured to feed air into the port transverse step portion when the hull is in motion on a body of water. The starboard transverse step portion extends to the starboard of the vessel from an intersection with the at least one starboard forward longitudinal step portion. The at least one starboard forward longitudinal step portion defines a longitudinal air pathway configured to feed air into the starboard transverse step portion when the hull is in motion on a body of water. In each partial-beam transverse step, no transverse step portion extends between the at least one port forward longitudinal step portion and the at least one starboard forward longitudinal step portion.
At least one port aft longitudinal step portion and at least one starboard aft longitudinal step portion may extend aft of the at least one longitudinally-vented, partial-beam transverse step. The respective forward and aft longitudinal step portions are preferably longitudinally aligned with one another such as to define an otherwise continuous longitudinal step extending forward and aft of the at least one partial-beam transverse step but for port and starboard discontinuities introduced by the at least one partial-beam transverse step.
Each longitudinal step portion may have a cross-sectional profile that comprises a cutout into the hull relative to a line defined by a deadrise angle of the hull, the cutout comprising a vertical rise starting from the line defined by the deadrise angle and a run tilted outwardly upward at a lesser, non-horizontal angle than the deadrise angle and that extends to an intersection with the line defined by the deadrise angle. The partial-beam, longitudinally-vented transverse step defines a plurality of longitudinally unrestricted transverse step air pathways configured to ventilate the partial-beam, longitudinally-vented transverse step from the port and starboard when the vessel is in motion on a body of water. The hull is preferably devoid of lifting strakes.
Embodiments may have any combination of partial-beam transverse steps and longitudinal steps, including embodiments with at least two longitudinally-vented, partial-beam transverse steps, or with only two longitudinally-vented, partial-beam transverse steps, with a plurality of longitudinal steps, wherein at least one longitudinally-vented, partial-beam transverse step intersects with all of the longitudinal steps or wherein at least one longitudinally-vented, partial-beam transverse step intersects with fewer than all of the longitudinal steps, with two longitudinal steps and two partial-beam transverse steps, and wherein each longitudinally-vented, partial-beam transverse step intersects with fewer than all of the longitudinal steps.
Each transverse step portion may taper from a maximum height at an inboard edge to a minimum height at an inboard edge. The maximum height of each transverse step portion may exceed the height of the longitudinal step with which the transverse step portion intersects. The transverse step portion may have a zero height at the inboard edge or a non-zero height at the inboard edge.
Another aspect of the invention comprises a marine vessel comprising at least one marine vessel hull as described herein. In preferred embodiments, the vessel comprises only a single hull, although multiple hull embodiments may also be provided.
As depicted in
Longitudinally-vented transverse steps not only allow air to be channeled from the sides of the transverse steps but also rammed from the longitudinal steps forward of the transverse steps, thus greatly increasing air volume feeding into the transverse steps. Unlike longitudinal lifting strakes, which have cross-sectional profiles that extend laterally away from the line defined by the deadrise angle of the hull in cross section, longitudinal steps have cross-sectional profiles that comprise cutouts into the hull relative to the line defined by the deadrise angle. These cutouts create a pocket for air flow. The two lines marked A in
In the embodiment illustrated in
Thus, each partial-beam, longitudinally-vented transverse step, as defined herein, comprises a port forward longitudinal step portion connecting to a port transverse step portion and a starboard forward longitudinal step portion connecting to a starboard transverse step portion. The port transverse step portion extends to the port of the vessel from an intersection with the port forward longitudinal step portion and the starboard transverse step portion extends to the starboard of the vessel from an intersection with the starboard forward longitudinal step portion. No transverse step portion extends between the port forward longitudinal step portion and the starboard forward longitudinal step portion.
As shown, the longitudinal step may optionally also extend aft of the transverse step, but some embodiments may only have forward longitudinal step portions. Although depicted in
Embodiments with more than one longitudinal step intersecting the transverse step(s) have at least one innermost inboard longitudinal step closest to the center line (e.g. step 132 in
The longitudinal steps aft of the aft-most transverse step may converge (i.e. their depth [sometimes also referred to as their height] reduces in size) at the aft, meaning that they have a first, relatively-greater depth in one portion of the vessel located forward of the aft and a second, relatively-lesser depth at the aft. The transverse step may have a height that tapers from maximum height at the intersection with the chine to a minimum height (and in some embodiments, such as depicted in
The degree of extension forward of the longitudinal step associated with a longitudinally vented transverse step is not limited to any particular length. In some embodiments, the longitudinal steps may converge forward to a zero depth, preferably along an “S” curve, such as to provide an air channel that is less restricted than would arise from continuing the longitudinal steps into, for example, the aft side of a transverse step located forward of the longitudinal step. The longitudinal steps may also be reintroduced gradually aft of the discontinuity caused by each transverse step, rather than abutting the transverse step.
Each partial-beam transverse step and its connected one or more longitudinal steps defines a set of air pathways along the longitudinal step(s) that feed(s) air into the partial-beam transverse step when the marine vessel is in motion on a body of water. The transverse step feeds the air into an air layer below the hull of the vessel aft of the transverse step. Because the transverse step does not extend from port to starboard, the air layer does not extend along the region 92 surrounding the centerline of the hull aft of the transverse step (as depicted in
The hull depicted herein comprises a non-entrapment hull having no amas or retaining rails or other structures extending downward into the water relative to the line defined by the deadrise angle of the hull. This non-entrapment design, characterized by an absence of amas or rails, facilitates water flow having a transverse component that smoothly follows the hull along the deadrise line A in cross section, as shown in
Although shown here as a combination of features, the invention is not limited to any particular combination. For example, the features of the partial-beam, longitudinally-vented transverse step as discussed herein may be applicable to any type of hull shape or size. Embodiments of the invention may include boat hulls having all of the described and depicted features or fewer than all of the described and depicted features. For example, although the embodiments depicted herein are devoid of lifting strakes, and the absence of lifting strakes may have certain advantages, such as reducing vertical acceleration and reducing the chattering, pounding and human and structural fatigue associated with such vertical acceleration, other embodiments may include designs having lifting strakes or any other appendage added to the hull.
Thus, embodiments of the present invention may comprise combinations of all or fewer than all of the following features:
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- at least one partial-beam, longitudinally vented transverse step (i.e. one or more longitudinal steps extending forward of one or more partial-beam transverse steps);
- one or more longitudinal steps extending aft of a partial-beam transverse step; and
- one or more longitudinal steps extending between a plurality of partial-beam transverse steps.
Although the embodiments depicted herein comprise a single partial-beam, longitudinally vented transverse step with a single longitudinally step having all of the above features, the invention is not limited to such a combination.
The boat hull designs as discussed herein may be incorporated into any type of marine vessel, but may be particularly well suited for use in sport fishing, military or performance vessels. The term marine vessel refers to any boat, yacht, or the like that is designed for travel on the surface of a body of water, including even vessels not designed for constant contact with water, such as for example, seaplanes. Similarly, the term hull refers to the portion of any such vessel that typically makes contact with the water when the vessel is normally operating in water.
Although illustrated herein in connection with a single hulled vessel, it should be understood that the hull design generally disclosed herein may be appropriate for use in connection with a multi-hull vessel, such as without limitation, a catamaran, a trimaran, or a vessel with any number of hulls known in the field in which each hull is separate and distinct from one another. When used in connection with a multi-hulled vessel, each of the multiple hulls may be identical and symmetrical, or each of the hulls may be different and asymmetrical relative to one another. For example, in a catamaran, each hull may comprise a mirror image of one another, such as a first hull essentially comprising the port half of the design of a single hull as illustrated herein, and a second hull comprising essentially the starboard half. In multi-hulled designs, each of the hulls retains its non-entrapment design. The area between the hulls, however, may or may not have an entrapment design.
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
Claims
1. A marine vessel hull having a port and starboard, the vessel comprising at least one longitudinally-vented, partial-beam transverse step, each longitudinally-vented, partial-beam, transverse step comprising:
- at least one port forward longitudinal step portion connecting to a port transverse step portion, the port transverse step portion extending to the port of the vessel from an intersection with the at least one port forward longitudinal step portion, the at least one port forward longitudinal step portion defining a longitudinal air pathway configured to feed air into the port transverse step portion when the hull is in motion on a body of water; and
- at least one starboard forward longitudinal step portion connecting to a starboard transverse step portion, the starboard transverse step portion extending to the starboard of the vessel from an intersection with the at least one starboard forward longitudinal step portion, the at least one starboard forward longitudinal step portion defining a longitudinal air pathway configured to feed air into the starboard transverse step portion when the hull is in motion on a body of water;
- wherein no transverse step portion extends between the at least one port forward longitudinal step portion and the at least one starboard forward longitudinal step portion.
2. The marine vessel hull of claim 1, wherein each longitudinal step portion has a cross-sectional profile that comprises a cutout into the hull relative to a line defined by a deadrise angle of the hull, the cutout comprising a vertical rise starting from the line defined by the deadrise angle and a run tilted outwardly upward at a lesser, non-horizontal angle than the deadrise angle and that extends to an intersection with the line defined by the deadrise angle.
3. The marine vessel hull of claim 1, further comprising:
- at least one port aft longitudinal step portion extending aft of the at least one longitudinally-vented, partial-beam transverse step;
- at least one starboard aft longitudinal step portion extending aft of the at least one longitudinally-vented, partial-beam transverse step.
4. The marine vessel hull of claim 3, wherein the at least one forward port longitudinal step portion and the at least one aft port longitudinal step portion are longitudinally aligned with one another and the at least one forward starboard longitudinal step portion and the at least one aft starboard longitudinal step portion are longitudinally aligned with one another such as to define at least one otherwise continuous longitudinal step extending forward and aft of the at least one partial-beam transverse step but for port and starboard discontinuities introduced by the at least one partial-beam transverse step.
5. The marine vessel hull of claim 1, wherein hull is devoid of lifting strakes.
6. The marine vessel hull of claim 1, wherein the partial-beam, longitudinally-vented transverse step defines a plurality of longitudinally unrestricted transverse step air pathways configured to ventilate the partial-beam, longitudinally-vented transverse step from the port and starboard when the vessel is in motion on a body of water.
7. The marine vessel hull of claim 1, wherein the hull comprises a plurality of longitudinal steps.
8. The marine vessel hull of claim 7, wherein at least one longitudinally-vented, partial-beam transverse step intersects with all of the longitudinal steps.
9. The marine vessel hull of claim 7, wherein at least one longitudinally-vented, partial-beam transverse step intersects with fewer than all of the longitudinal steps.
10. The marine vessel hull of claim 7, comprising a plurality of partial-beam transverse steps.
11. The marine vessel hull of claim 10, wherein one of the plurality of longitudinally-vented, partial-beam transverse steps intersects with more longitudinal steps than another of the plurality of longitudinally-vented, partial-beam transverse steps.
12. The marine vessel hull of claim 11, comprising exactly two longitudinal steps and exactly two partial-beam transverse steps.
13. The marine vessel hull of claim 12, wherein each longitudinally-vented, partial-beam transverse step intersects both longitudinal steps.
14. The marine vessel hull of claim 12, wherein each longitudinally-vented, partial-beam transverse step intersects with only one of the longitudinal steps.
15. The marine vessel hull of claim 1, wherein each transverse step portion of the at least one transverse step tapers from a maximum height at an inboard edge to a minimum height at an inboard edge.
16. The marine vessel hull of claim 15, wherein the maximum height of each transverse step portion exceeds a height of the longitudinal step with which the transverse step portion intersects.
17. The marine vessel hull of claim 15, wherein each transverse step portion has a zero height at the inboard edge.
18. The marine vessel hull of claim 15, wherein each transverse step portion has a non-zero height at the inboard edge.
19. A marine vessel comprising at least one marine vessel hull of claim 1.
20. The marine vessel of claim 19, wherein the vessel comprises only a single hull.
Type: Application
Filed: Apr 17, 2020
Publication Date: Oct 22, 2020
Inventor: Stephen Daniel Matthews (Stuart, FL)
Application Number: 16/851,506