WO2008033161A1

WO2008033161A1 - Sailboat hull

Info

Publication number: WO2008033161A1
Application number: PCT/US2007/004425
Authority: WO
Inventors: Edwin Joseph Salisbury
Original assignee: Edwin Joseph Salisbury
Priority date: 2006-09-15
Filing date: 2007-02-21
Publication date: 2008-03-20

Abstract

The invention is a sailboat hull design, intended for use by yacht designers or naval architects in the creation of light displacement racing and cruising monohull sailboats. The hull design has two bows integrated into a monohull shape, resulting in a light displacement hull type with enhanced form stability and reduced form drag.

Description

DESCRIPTION

Sailboat Hull

1. Technical Field: The invention relates to monohull sailboat design, which is a part of the technical field of naval architecture.

2. Background Art: The invention occurs within the context of modern monohull sailboats with keels, in particular the development of light displacement planing designs. The lighter the sailboat, the faster the sailboat can travel; however, along with light displacement there is a corresponding decrease in the amount of keel ballast that can counteract the heeling force of wind on the sails.

Sailboat hull design solutions to date have involved hull shapes with wide beams, since a wide beam creates form stability, which helps resists the - heeling force of wind on the sails. Because a single bow is used on current monohull sailboat designs, the pointed bow in combination with a wide beam at the stern results in a roughly triangular plan shape. This triangular plan shape creates form drag through the water, because when the hull is heeled, the immersed body of the hull points in a different direction to the direction of travel (see reference 1).

Scow dinghies use a blunted bow in order to increase form stability and reduce form drag. However, a blunt bow is only appropriate for calm inland waters, where the bow is not required to go through waves or chop. As a result, scow dinghies race on inland bodies of water only, and monohull sailboats do not use this design approach. References:

1. Illustration of immersed hull body for boat with wide beam and single bow: http^/www.finot.com/ecrits/ecritqroupe/αuestionmois/arrierelarαe.htm

2. Illustration of scow dinghy with blunted bow: http://www.lhvcsailing.com/fleet/fleet.html - Z -

3. Disclosure of Invention: The invention provides an improvement to the existing trends in monohull sailboat design by creating a hull with two bows. This design has the benefit of increased form stability, because the wide beam is maintained from the bow to the stern. It also has the benefit of reduced form drag, because when the hull is heeled, the immersed body of the hull aligns with the direction of travel. Unlike a scow dinghy, the two bows create a pointed end that can penetrate waves or chop when heeled, since typically only one bow would be immersed at a time.

A further benefit is the creation of additional hull surface in the middle and forward sections of the boat, which will support hull planing at lower speeds.

The hull shape has a higher initial wetted surface area, but at fairly low angles of heel much of the wetted surface area rises out of the water, with the result that the immersed body of the hull has a canoe like shape when heeled, with correspondingly low frictional drag.

There is no limitation regarding a maximum or minimum size of the hull, although the proportions of the hull would vary with the particular size of each sailboat application. That is, the relative proportions of a 6 meter long hull would be different from those of a 20 meter long hull, while maintaining the basic form of two bows blending into an overall monohull form with a single stern.

4. Brief Description of Drawings: Drawing 1 of 2 contains a perspective view of the invention. Drawing 2 of 2 contains a plan view of the invention, along with front, back, and right elevations.

5. Best Mode for Carrying Out the Invention: The invention is compatible with existing industry practices for hull, keel, rudder, and rig design and construction. No special technologies are required for the implementation of the invention. The invention would be licensed for use by yacht designers and/or naval architects, who would modify the size and proportions of the invention as needed for their specific project.

6. Industrial Applicability: The invention is most applicable for use in custom or mass produced racing monohull sailboat designs. There is additional specialized applicability to custom or mass produced light displacement cruising monohull sailboat designs.

Claims

1. Statement of Prior Art: Monohull saiboat designs, characterized by a hull with a single stern and bow, are part of the prior art, but also necessary for the definition of the invention.

2. Statement of Features for Which Protection is Sought: The invention is characterized by the presence of two bows, which are blended into an overall monohull form with a single stern.