The Wave Powered Boat
Solo sailor Kenichi Horie has used wind, solar and man power through a series of nautical adventures. For his latest undertaking, he harnessed the energy of the waves. Tsuneishi Shipbuilding Company built the Suntory Mermaid II, reportedly the world's first wave powered boat. Suntory Mermaid II has an overall length of 9.5 meters, a maximum width of 3.5 meters and a weight of three tons, and is homeported at Nishinomiya Yacht Harbor. Horie departed from Honolulu's Hawaii Yacht Club in mid-May 2008 and crossed about 7,000 km of ocean, arriving back at the Kii Channel. The trip's planned duration of 2.5 months was extended to 111 days, as good weather and calm seas resulted in a speed of only 1.5 knots. Wave powered boats feature fins at the front of the craft, which generate thrust force by moving up and down like the tails of dolphins and whales and absorbing the energy of the waves. The lone researcher of wave powered boats, Professor Hiroshi Terao of Tokai University's oceanography department, assisted in the construction of a vessel to bring Kenichi Horie's dream of wave powered sailing to life. Because the fins absorb energy from the pitching motion of the boat, the pitching decreases and the boat's stability is improved. Under normal use the sole power source is wave energy, but the boat can also use sails or an outboard motor when entering or leaving harbor, or in case of emergencies. While cruising, the outboard motor and sails will not be used. Ichiro Yokoyama, the ship's designer, was a chief designer of the ship "Nippon Challenge" which sailed in the America's Cup, the world's premier yacht race. A catamaran (twin-hulled ship) with two fins was designed as the optimum configuration for the harnessing of wave energy. The body of "SUNTORY Mermaid II" uses recycled aluminum material. The catamaran body, at 9.5 m (31 ft.) in length, uses an aluminum alloy (A5083) which is more durable and corrosion resistant than other recycled aluminum, an important consideration given the duration and rigors of the voyage. Additionally, Tsuneishi Forestry Construction Company, which was in charge of building the boat, utilized its aluminum processing technology to create a light body using aluminum sheets only 3 mm in thickness for the outer hull, though 5 mm is considered standard. The onboard power source for "SUNTORY Mermaid II" is an estimated 650 watt solar cells (Solar battery generator) generating power for the navigation light (installed at the top of the mast), ham radio, iridium satellite phone, and PC.
www.tsuneishi.co.jp Collaboration
Tokai University, Sumitomo Light Metal Industries, Ltd. TSUNEISHI Holdings Company, SHARP Corporation, Hawaii Yacht Club, Kansai Yacht Club, Shin-Nishinomiya Yacht Harbor Co., Ltd., and Nishinomiya City
42 MN
September 2008