Carbon rudder for 147' sloop

GMT Composites recently shipped this extraordinary rudder to Vitters Shipyard in The Netherlands for installation in a 44.7 meter (147-foot) sloop under construction there. Lady B, designed by Dubois Naval Architects and scheduled for 2009 delivery, is a flush-deck mega-sailer with cutting-edge styling and state-of-the-art technology in construction, materials as well as gear and equipment.
Because sailing performance is a key factor in the design brief (Lady B will sail at over 20 knots), this aluminum-hulled sloop features a towering high-aspect rig, a lifting keel with 4-6 meter (14-20 feet) draft and 240-tonnes displacement. Those factors will generate loads on her rudder appendage which could only be practically solved with a carbon composite solution. Because GMT had previously worked successfully with both her designer and her builder on mega-sailer rudders, they returned to GMT for this critical component.
The GMT rudder is 6.1 meters (20 feet) in height, has a chord depth of 1.4 meters (4 feet 6 inches) and yet, including the carbon stock, weights only 421 kg (926 pounds). A rudder built with a steel stock and at these dimensions and equivalent strength would weigh 5-times as much, an unacceptable situation when lightening weight in the ends of the yacht is so important for enhancing sailing performance.
Lady B’s rudder is shown alongside the GMT-built rudder for a Frers 44, just to give more sense of scale. GMT has engineered and built carbon composite rudders for sailboats throughout this range of sizes as well as smaller, and we anticipate building ones even larger.
For more, go to Rudders & Stocks.