US 10,160,517 B1Granted

Watercraft hull with angled keels

OwnerHoward D. Harleyinventor

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Abstract

A pressurized air cushioned hull with fixed rigid side, front and rear seals. The hull includes a plurality of keels, with an air cushion disposed between inboard walls of each keel and an air cushion created/disposed along the outboard walls of each keel. These air cushions along the outboard walls of the keels are created by angling each keel by about 0.02° to about 1° relative to the longitudinal axis of the hull, wherein the left keel(s) is rotated clockwise and the right keel(s) is rotated counterclockwise, such that a distance between the keels is smaller at the front end of the keels than at the rear end of the keels. This slight angle was found to allow air, rather than water, to contact the outboard walls, unexpectedly reducing drag resistance a significant amount, thus improving performance of the hull as a whole.

Claims21

Dependent claims

A hull of a watercraft, comprising:

a first keel positioned laterally on one side of a longitudinal axis of the hull, wherein the first keel is
inwardly angled toward the longitudinal axis of the hull at a forward end of the first keel, and
outwardly angled away from the longitudinal axis of the hull at a rear end of the first keel;
a second keel positioned laterally on an opposite side of the longitudinal axis of the hull, wherein the second keel is
inwardly angled toward the longitudinal axis of the hull at a forward end of the second keel, and
outwardly angled away from the longitudinal axis of the hull at a rear end of the second keel,
wherein the first and second keels are oblique to each other, such that
a fore spaced distance exists between the first keel and the second keel at the forward ends of the first and second keels,
a rear spaced distance exists between the first keel and the second keel at the rear ends of the first and second keels, and
the rear spaced distance is greater than the fore spaced distance,
whereby an angled configuration of the first and second keels creates a first air cushion along an outboard wall of the first keel and a second air cushion along an outboard wall of the second keel, thus reducing drag resistance experienced by the hull traveling through water.

8 more elements

A surface effect vessel hull having a central longitudinal axis, said surface effect vessel hull comprising:

a first catamaran hull and a second catamaran hull joined together by a deck, each catamaran hull defining a longitudinal dimension;
wherein said first catamaran hull is positioned on a left side of said central longitudinal axis and said second catamaran hull is positioned on a right side of said central longitudinal axis,
wherein said first catamaran hull defines a first set of keels that are inwardly slanted at a front end of said first set of keels and outwardly slanted at a rear end of said first set of keels, the inward and outward slants being relative to said longitudinal dimension of said first catamaran hull,
such that said first set of keels are oblique to each other with said first set of keels having a fore distance between each other at said front end and a rear distance between each other at said rear end, said fore distance between said first set of keels being smaller than a rear distance between said first set of keels,
wherein said first set of keels are slanted relative to said longitudinal dimension of said first catamaran hull at an angle of about 0.05° to about 0.50°,
wherein said second catamaran hull defines a second set of keels that are inwardly slanted at a front end of said second set of keels and outwardly slanted at a rear end of said second set of keels, the inward and outward slants being relative to said longitudinal dimension of said second catamaran hull,
such that said second set of keels are oblique to each other with said second set of keels having a fore distance between each other at said front end and a rear distance between each other at said rear end, said fore distance between said second set of keels being smaller than a rear distance between said second set of keels,
wherein said second set of keels are slanted relative to said longitudinal dimension of said second catamaran hull at an angle of about 0.05° to about 0.5°,
wherein said first set of keels and said second set of keels are symmetric to each other about said central longitudinal axis of said surface effect vessel hull,
said first set of keels and said second set of keels each having inboard walls and outboard walls;
a left inboard air cushion created between said inboard walls of said first set of keels;
a right inboard air cushion created between said inboard walls of said second set of keels;
one or more left outboard air cushions created along said outboard walls of said first set of keels;
one or more right outboard air cushions created along said outboard walls of said second set of keels;
a length-to-beam ratio of about 7% to about 12% for said left inboard air cushion and said right inboard air cushion relative to the longitudinal axis of the hull,
wherein said length-to-beam ratio of said left inboard air cushion is about 9% at said front end of said first set of keels and about 10% at said rear end of said first set of keels,
wherein said length-to-beam ratio of said right inboard air cushion is about 9% at said front end of said second set of keels and about 10% at said rear end of said second set of keels,
whereby said left inboard air cushion, said right inboard air cushion, said one or more left outboard air cushions, and said one or more right outboard air cushions collectively reduce drag resistance experienced by said surface effect vessel hull through water,
whereby said drag resistance of said surface effect vessel hull through water is reduced by about 24% to about 42% relative to said left inboard air cushion and said right inboard air cushion alone without said one or more left outboard air cushions and said one or more right outboard air cushions.

16 more elements

Dependencies are inferred from the claim text.