LLOYD M TREFETHEN
Engineering in Lexington, MA
License number
Massachusetts 16658
Expiration Date
Jun 30, 1984
Type
Mechanical Engineer
Address
Address
Lexington, MA 02421
Professional information
Dual Hull Watercraft
US Patent:
5896825, Apr 27, 1999
Filed:
Oct 31, 1997
Appl. No.:
8/961746
Inventors:
Lloyd M. Trefethen - Lexington MA
International Classification:
B63B 3500
US Classification:
114 3928
Abstract:
In a dual-hull watercraft, a separate keel hull and sail hull are connected by a tie line. The sail hull comprises a sail and hull without a keel. The keel hull comprises a keel and hull or a submerged keel. The flexible tie line is coupled to the keel at or near the keel center of effort and is coupled to the sail at or near the center of sail effort. During operation, the sail and keel are configured to "toe in" relative to each other, maintaining tension in the tie line allowing the sail and keel to provide for the other's drag. The tie line allows for directional steering of the craft without a rudder, and for controlling the speed of the craft and the heel angles of the sail and keel hulls. Two gliders similarly connected can exploit wind velocity differences and are operable without updrafts.