Pegasus-class hydrofoil



The Pegasus-class hydrofoils were a series of fast attack patrol boats employed by the U.S. Navy. They were in service from 1977 through 1993. These hydrofoils carried the designation "PHM" for "Patrol, Hydrofoil, Missile." The Pegasus class vessels were originally intended for NATO operations in the North Sea and Baltic Sea. Subsequently, participation by other NATO navies, including Germany and Italy, ceased and the U.S. Navy proceeded to procure six PHMs, which were highly successful in conducting coastal operations, such as narcotics interdiction and coastal patrol, in the Caribbean basin.

History
In the late 1960s, NATO developed a requirement for a small, fast warship to counter large numbers of Warsaw Pact missile boats, such as the Komar and Osa class missile boats, deciding that a hydrofoil would be the best way to meet this requirement. In 1970 Admiral Elmo Zumwalt, the new Chief of Naval Operations (CNO), keen to increase the Navy's number of surface vessels in a cost-effective manner, committed the United States to the NATO program for a hydrofoil. The US Navy proposed the PHM design as a NATO standard, with the program being led by the US Navy, and an order placed for two prototypes in 1972. The Italian Marina Militare and the German Bundesmarine signed letters of intent to participate in the programme, with other NATO navies, including the Royal Navy and Canadian Forces studying the project. The US Navy planned to buy up to 30 PHMs, with 10 to be purchased by Germany and four by Italy.

After Zumwalt's retirement, the Navy chose to funnel most of the money for the PHMs into larger vessels. This delayed the ongoing construction of Pegasus, and the other vessels were not started. Congress eventually forced the Navy to complete the vessels. The difficulties in project progression forced the other involved navies to abort their participation.

The Pegasus class ships were powered by two 800 horsepower (600 kW) twin turbo-charged Mercedes-Benz diesels when waterborne using water jets giving them a speed of 12 knots. When foilborne, the ships were powered by a General Electric LM2500 gas turbine and a very large water jet giving them a speed of 48+ knots.

Pegasus ships were well armed for their size, carrying two four-rack RGM-84 Harpoon anti-ship missiles and an Oto Melara 76 mm gun. The Harpoons, specifically, were capable of sinking far larger ships at distances in excess of 60 nmi. The German version would have carried the MM38 Exocet.

As Pegasus was constructed several years before the rest of the series, there are some slight differences, such as the fire-control system.

All six vessels were constructed by Boeing, in Seattle at the Renton plant at the south end of Lake Washington. They were stationed at NAS Key West.

The technology was first pioneered by the USS Tucumcari (PGH-2), where it successfully operated in Vietnam, but ultimately ran aground off Puerto Rico. It was judged to be more advanced than the Grumman USS Flagstaff (PGH-1) which was built at the same time to the same requirements. The primary technology, also used in the Boeing Jetfoil ferries, used submerged flying foils with waterjet propulsion.

The ships were retired because they were not judged cost effective for their mission in a Navy with primarily offensive missions rather than coastal patrol. USS Aries PHM-5 Hydrofoil Memorial, Inc. obtained Aries for rehabilitation as a memorial located on the Grand River in Brunswick, Missouri at 39.42083°N, -93.12972°W. All other PHMs in the class have been scrapped except for Gemini which was converted into a yacht.

List of ships

 * USS Pegasus (PHM-1) (July 9, 1977–July 30, 1993), formerly Delphinus
 * USS Hercules (PHM-2) (December 18, 1982–July 30, 1993)
 * USS Taurus (PHM-3) (October 10, 1981–July 30, 1993)
 * USS Aquila (PHM-4) (June 26, 1982–July 30, 1993)
 * USS Aries (PHM-5) (September 18, 1982–July 30, 1993)
 * USS Gemini (PHM-6) (November 13, 1982–July 30, 1993)