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Hydrofoils: Ships That Fly

March 27, 2017 | By Megan Churchwell, Curator, Puget Sound Navy Museum
The U.S. Navy's fleet of big ships is balanced by a diverse collection of smaller vessels including speedy patrol boats. Of these, hydrofoil patrol boats were some of the most unusual vessels of the U.S. Navy fleet.
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Photo By: NHHC
VIRIN: 210624-N-ZX259-3065

And now, thanks to the U.S. Navy's first operational hydrofoil, was launched in 1962. Operating from the Puget Sound Naval Shipyard, she underwent testing at speeds of more than 50 knots. It was hoped that hydrofoils like High Point would join the fleet as antisubmarine warfare vessels. However, testing revealed that the hydrofoil technology was not yet advanced enough to produce a reliable hydrofoil to join the fleet, and more research was needed. Still, much was learned through these tests. In 1975, High Point was transferred to the U.S. Coast Guard for evaluation as a coastal patrol vessel.
USS Plainview (AGEH 1)
USS Plainview (AGEH 1) was built by Lockheed Shipbuilding and Construction Company and operated out of the Puget Sound Navy Shipyard from her 1969 commissioning until 1978. At 220?, she was the world's largest military hydrofoil. She tested the feasibility of large hydrofoil craft operations at sea. Plainview was used to show the effectiveness of hydrofoils in accomplishing Navy missions like launching torpedoes, firing missiles, and underway replenishment. USS Plainview reminded many crew members of an airplane, with her aluminum construction and Lockheed jet aircraft engines. Her bridge was often compared to an airplane cockpit because of the many dials and gauges.
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Photo By: NHHC
VIRIN: 210624-N-ZX259-2990

USS Tucumcari (PGH 2)
USS Tucumcari (PGH 2), designed by Boeing, was the first weapon-equipped military hydrofoil. The heavily-armed "TUC" was launched in 1967. She measured 71' long, and carried a 40mm cannon, four .50 caliber machine guns, and an 81mm mortar. Early Boeing hydrofoil test pilot Vern Salisbury, who had been a Marine fighter pilot during the Korean War, said that hydrofoils offered more thrills than flying. On testing runs aboard USS Tucumcari, he ran rings around Coast Guard patrol boats and even circled nuclear submarines. "Heads would pop out of the hatches as we would circle," he recalled. At the time, the top speed (more than 50 knots per hour) was considered classified. Following extensive tests in Washington and California, Tucumcari was sent to Vietnam, becoming the first U.S. Navy hydrofoil to see combat duty.

USS Pegasus and the Navy's PHM Program
After the success of USS Tucumcari, the Navy asked Boeing to produce a larger armed hydrofoil. The PHM (Patrol Hydrofoil Missile) program consisted of six hydrofoil patrol boats. At 132 feet, they were nearly twice as long as Tucumcari. Heavily armed for their size, with a 76mm rapid-fire gun and eight Harpoon missiles, PHM boats could challenge much larger warships. Launched by Boeing between 1974 and 1982, all six Pegasus-class hydrofoils were assigned to patrol the waters around Key West, Florida to combat drug trafficking. With speeds in excess of 40 knots in any weather, they were the only U.S. ships that could outrun the speedy boats used by smugglers.

The End of an Era
In 1993, the PHMs were decommissioned due to government cutbacks. However, the technology developed by the PHM program contributed to the creation of several types of commercial hydrofoils, such as the Boeing Jetfoil passenger ferries launched in the 1980s. The Puget Sound Navy Museum's newest exhibit, "Patrol Boats on Puget Sound," features hydrofoils and other small, fast patrol boats that have operated on Puget Sound for more than a century. "Patrol Boats on Puget Sound" opened on March 3, 2017 and will remain on view for two years.

Check out the 1975 Navy documentary video on the hydrofoil technology of the USS Pegasus (PHM-1)

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