All six members of the Pegasus class of armed hydrofoilsThe patrol combatant missile hydrofoils USS Aquila (PHM 4), front, and USS Gemini (PHM 6), center, lie tied up in port with a third PHM. The Coast Guard surface effect ship (SES) cutter USCGC Shearwater (WSES 3) is in the background.
The Pegasus-class hydrofoil was a series of six missile-armed patrol hydrofoils (PHMs) operated by the United States Navy from 1977 to 1993. Initially intended to counter Warsaw Pactmissile boats such as the Osa-class in NATO littorals. The class proved expensive to operate, fuel-intensive, and carried firepower disproportionate to its primary missions of coastal patrol and counter-narcotics operations.[1][2]
In the late 1960s, NATO sought a small, fast surface combatant to counter Soviet missile boats, but the resulting project was poorly conceived. The United States proposed the PHM as a NATO standard, initially planning up to 30 vessels, with options for Germany and Italy. However, lack of commitment from partners and the Navy’s focus on larger ships reduced the programme to just six USN vessels. The project suffered repeated cost overruns and construction delays, and Congressional oversight was selective, concentrating on ensuring completion rather than providing an effective, timely, and capable solution.[3]
Design and armament
The PHMs employed a combined diesel and gas turbine (CODOG) propulsion system with water-jet drives. Diesel engines provided fuel-efficient hullborne speeds up to 12 knots, while a LM2500 gas turbine powered foilborne speeds exceeding 48 knots. Fuel consumption was approximately 1,000 gallons per hour when foilborne and 100 gallons per hour hullborne, significantly limiting endurance.[4]
Armament comprised a 76 mm Oto Melara gun and provision for two quadruple RGM-84 Harpoon missile launchers, although the missiles were seldom carried as they made the class top heavy.[1] While effective against larger surface combatants, this level of firepower was rarely needed in the PHMs’ primary coastal patrol and counter-narcotics roles, highlighting a mismatch between design and mission profile.[5]
Operational history
All six vessels were constructed by Boeing in Renton, Washington, and based at Naval Air Station Key West, Florida. Despite their speed, limited endurance, maintenance requirements, and high fuel consumption restricted sustained operations.[1]
Cost and decommissioning
The 1979 GAO report identified alarming cost inefficiencies in the PHM programme, including overpricing and inadequate spare provisioning. High operational costs, combined with a small fleet and limited mission profiles, led to retirement of the class by 1993.
The Aries was preserved as a memorial on the Gasconade River in Missouri. Gemini was briefly converted into a yacht before being scrapped, and the remainder were sold for scrap.[6][7]
List of ships
Pegasus(PHM-1) (9 July 1977 – 30 July 1993), formerly Delphinus
Gardiner, Robert and Stephen Chumbley. Conway's All The World's Fighting Ships 1947–1995. Annapolis, Maryland, USA: Naval Institute Press, 1995. ISBN1-55750-132-7.
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