Hydrofoil
A hydrofoil is a boat with wing-like foils mounted on struts below the hull. As the craft increases its speed the hydrofoils develop enough lift for the boat to become foilborne - i.e. to raise the hull up and out of the water. This results in a great reduction in drag and a corresponding increase in speed.
Early hydrofoils used U-shape foils, but modern hydrofoils use T-shape foils which allow better maneuverability.
A March 1906 Scientific American article by American hydrofoil pioneer William E. Meacham explained the basic principle of hydrofoils. Alexander Graham Bell considered the invention of the hydroplane a very significant achievement. After reading this article Bell began to sketch concepts of what is now called a hydrofoil boat. With Casey Baldwin he began hydrofoil experimentation in the summer of 1908. Baldwin studied the work of the Italian inventor Enrico Forlanini and began testing models based on his designs. This lead him and Bell to the development of hydrofoil watercraft. During Bell's world tour of 1910-1911 he and Baldwin met with Forlanini in Italy. They had rides in the Forlanini hydrofoil boat over Lake Maggiore. Baldwin described it was as smooth as flying. On returning to Baddeck a number of designs were tried culminating in the HD-4. Using Renault engines a top speed of 54 mph (87 km/h) was achieved, accelerating rapidly, taking wave without
difficulty, steering well and showing good stability. Bell's report to the United States Navy permitted him to obtain two 350 horsepower (260 kW) engines. On September 9, 1919 the HD-4 set a world's marine speed record of 70.86 mph (114 km/h). This record stood for ten years.
The Soviet Union experimented extensively with hydrofoils, constructing hydrofoil ferries with streamlined designs, especially during the 1970s and 1980s. Such vessels include the Meteor type and the smaller Vokhod type; these vessels have inspired people in the former Soviet Union to continue tinkering with hydrofoils and selling them to hydrofoil operators.
The U.S. Navy operated combat hydrofoils, such as USS Pegasus, from 1977 through 1993. These hydrofoils were fast and well armed, and were capable of sinking all but the largest surface vessels. In their narcotics interdiction role, they were a nightmare for drug runners, being very fast, and having missiles and guns to stop anything they could not catch, as well as the ability to call in air support.
Some operators of hydrofoil include:
See also
