Ships – Watercraft with means used in providing sailpower – Having specifically defined hull shape
Patent
1982-10-27
1985-11-26
Blix, Trygve M.
Ships
Watercraft with means used in providing sailpower
Having specifically defined hull shape
114 90, B63H 908
Patent
active
045548811
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to sailing craft and in particular to a system of sailor location.
The system subject of the invention may be compared by analogy with "trapeze systems" currently in use in relation to sailing craft although provides advantages to a sailor not normally attributable to a conventional "trapeze system". It is the object of the present invention to facilitate location of a sailor's body in various controlled and stable relationships to a sailing craft during all aspects of normal sailing and additionally wave jumping and "gliding".
In order that the sails of small unbalasted or lightly balasted craft sailing "close hauled" with respect to the wind may generate a horizontal forward (with respect to the craft's hull) motive force an undesirable heeling moment is generated about the fore aft axis of the hull, such force acting to capsize the vessel unless counteracted by an equal and opposite righting moment.
It has been the practice for many years to provide the equal and opposite righting moment abovementioned by utilising the weight of one or more sailors aboard the craft at points to the windward side of the fore aft axis of the craft and preferably outboard of the hull. In order that a sailor may locate his body weight at a point outboard of the crafts hull according to conventional means the sailor is provided with a harness about the wearer's torso releasably connected to a "trapeze" wire suspended from a point upon the upper regions of the mast of the craft. The length of such trapeze wire is adjusted so as to maintain the users torso above sea level with the vessel in a substantially upright position, the users feet resting upon the gunwale of the vessel and the users body almost entirely outboard of the hull.
Conventional dingy type hulls display considerable inherent "form" stability due to a relatively high beam/length ratios and such high beam/length ratio hull additionally affords a sailor the capability of placing his body weight at a considerable distance from the longitudinal centre line of the boat but not outboard of the gunwale thereby providing a considerable righting moment without utilising a trapeze system or other system designed to facilitate the placement of the sailors entire bodyweight outboard of the gunwale. Even when a trapeze system is provided with the conventional "dingy" hull having the aforementioned comparatively high beam/length ratio the trapeze system is relatively simple to master as the "form" stability of such hulls prevents capsize when an inexperienced sailor using a trapeze is a little late in swinging inboard of the the gunwale in a lull or places his bodyweight in a position on the hull other than in very close proximity to the centreline of such hull.
Board type sailing craft having low beam/length ratio hulls have recently become popular in conjunction with non-stayed masts mounted upon some type of universal joint at the junction of the mast and hull. The movable unstayed masts of such vessels are adapted to fall into non-perpendicular relationship to the hull should the sailor misjudge the necessary trim of the sail dictated by prevailing wind conditions thereby preventing what would be a capsize in a vessel with a stayed mast or mast otherwise secured in a perpendicular relationship to the hull. Such vessels as last described with moveable masts, commonly described as "sailboards", additionally permit movement of the board out of a substantially horizontal alignment with the water without necessarily altering mast and hence sail trim and this feature renders such craft forgiving in so far as placement of a sailor's body weight in respect of a hull/board having little "form" stability.
The advantages of fast manoeuvreable low beam/length ratio board type hulls are difficult to exploit in conjunction with the advantages of a conventional fixed and stayed mast rig due to the fact that, in order to counteract the heeling moment of the sail the sailor's body weight must be capable of being placed outboard of the gu
REFERENCES:
patent: 2364578 (1944-12-01), Wilkie
patent: 3217833 (1965-11-01), Smith
patent: 3716232 (1973-02-01), Johnson et al.
patent: 3837642 (1974-09-01), Martin
patent: 3985090 (1976-10-01), Rineman
patent: 4418631 (1983-12-01), Frohbach
Avila Stephen P.
Blix Trygve M.
Illirrie Holdings Pty Ltd.
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