Wing boat sail rigging - has rigid flat aerodynamic surfaces with angle of attack controlled by trim tabs

摘要

The boat propulsion sail rigging comprises one or more rigid flat aerodynamic surfaces, secured by ropes. They can be secured to trucks travelling on a circular rail on or above the boat deck, and there can be three on the same mounting. The angle of the surfaces can be adjusted by a Flettner aileron or trim tab, a mechanism acting between hull and rigging, one acting on the rail trucks, or a combination of any of them. The design gives a high degree of aerodynamic efficiency as compared with conventional sails.