US 7,418,915 B2 · Entrapment tunnel monohull optimized 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.

Claims44

Dependent claims

A watercraft comprising a center hull and a pair of outer side hulls respectively located on opposite sides of the center hull and including outer surfaces forming portions of the outer sides of the watercraft, 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;

said outer surfaces of the side hulls being substantially vertical to the water surface when the hull is at rest and extend to a lower keel;
said center hull also having vertical surface portions facing the reverse deadrise surface portions of said outer hulls;
and said center hull including a deadrise surface portion on each of its sides extending from said vertical surface portions and intersecting with the reverse deadrise surface portion of its adjacent outer hull, whereby said vertical surface portions, reverse deadrise surfaces and deadrise surface portions define an air entrapment tunnel on each side of the center hull;
said lower edges of said outer hulls extending to a greater depth below the waterline than said vertical surface portions of the center hull.

1 more element

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 stern, 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;

said center hull having vertical surface portions facing the reverse deadrise surface portions of said outer hulls;
said center hull also including 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;
said reverse deadrise decreasing on said outer hulls from bow to stem;
said center hull having an at rest design water line;
and said reverse deadrise of the inner surface portions of the side hulls sloping fore to aft;
said center hull including a plurality of running strakes which run from the bow of the center hull to a predetermined point amidship;
said hulls having 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.

4 more elements

Dependencies are inferred from the claim text.

Entrapment tunnel monohull optimized waterjet and high payload

Life of this patent

Entrapment tunnel monohull optimized waterjet and high payload

Life of this patent

Abstract

Claims44