The mathematics of wind power has fascinated Nova Scotia native Brad Blackford for decades.
A physicist by education, his first windmill boats were built on Hobie and Tornado Catamaran hulls, but he “needed a special design” to better test his theories.
Blackford built this windmill boat after he retired, about seven years ago.
“It was designed by a theory I worked out,” said Blackford. “I played with the design for many years.”
The twin hulls, which needed to be “pointed on both ends,” are made from thin wood covered by fiberglass and can be expanded from an eight to ten foot beam. Each rotor blade, nine feet in length, is made with fiberglass-covered foam.
The windmill can rotate 360 degrees, regardless of the direction the boat is facing, but harvests only fifty percent of the wind speed. A hydrofoil sits below the waterline, which lifts the boat during forward motion and allows it to ‘sail’ straight into the wind. This boat can do eight knots into the wind and 12 knots downwind.
“It is designed for maximum net force, not maximum power,” he said. “A subtle difference.”
Blackford and Vera, his wife of 52 years, trailer the windmill boat from Halifax to Stuart, Florida each February where they stay for two months. Docked at Sunset Bay Marina on the Saint Lucie River, the boat draws a lot of attention. Skippers on sport fishers, megayachts and skiffs slow down to take a closer look. It is not uncommon to see sets of binoculars as heads turn to watch the one-of-a-kind boat silently sail by.
“This started out as a hobby,” said Blackford, “which became addictive.”
Kathy Enzerink writes regularly for All at Sea Southeast.
Can you please send me details of what happens under water ie the prop.