View source for Pegasus-class hydrofoil

{{Short description|Class of U.S. Navy patrol boats}}
{{refimprove|date=November 2009}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image= [[File:PHM-1.jpg|300px|USS Pegasus]]
|Ship caption={{USS|Pegasus|PHM-1}}
}}
{{Infobox ship class overview
|Name=''Pegasus''-class hydrofoil
|Builders=[[Boeing Integrated Defense Systems|Boeing Marine Systems]], [[Boeing Renton Factory|Renton, Washington]]
|Operators={{navy|United States}}
|Class before=
|Class after=
|Subclasses=
|Cost=
|Built range=1973&ndash;1982
|In service range=
|In commission range=1977&ndash;1993
|Total ships building=
|Total ships planned=
|Total ships completed=6
|Total ships cancelled=
|Total ships active=
|Total ships laid up=
|Total ships lost=
|Total ships retired=6
|Total ships preserved=1
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship class=
|Ship displacement= {{convert|237.2|LT|t|0|abbr=on}}
|Ship length= {{convert|133|ft|m|abbr=on}}
|Ship beam= {{convert|28|ft|m|abbr=on}}
|Ship propulsion=*2 × Mercedes-Benz [[MTU Friedrichshafen|MTU]] marine diesels (hullborne), {{convert|1600|bhp|0|abbr=on}}
*1 × [[General Electric LM2500]] gas turbine (Foilborne), {{convert|18000|shp|0|abbr=on}}  
|Ship speed=*{{convert|12|kn|lk=in}} hullborne
*{{convert|48|kn}} foilborne
|Ship range= 
|Ship complement= 4 officers, 17 enlisted
|Ship sensors=*LN-66 navigation radar
*MK 94 Mod 1 (PHM-1), MK 92 Mod 1 (PHM 2-6) [[fire-control system]]
|Ship EW=
|Ship armament=*8 × [[Boeing AGM-84 Harpoon|Harpoon]] [[Surface-to-surface missile]]
*1 × [[Otobreda 76 mm|Mk 75 76 mm OTO Melara]], 62 cal. gun
|Ship armour=
|Ship aircraft=
|Ship notes=
}}
|}
[[File:Six Pegasus class hydrofoils underway.jpg|thumb|All six members of the ''Pegasus'' class of armed hydrofoils]]
[[File:DN-SC-90-09333.jpg|thumb|The 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 hydrofoils''' were a series of [[Fast Attack Craft|fast attack]] [[patrol boat]]s employed by the [[United States Navy]]. They were in service from 1977 until 1993. These [[hydrofoil]]s 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 [[narcotic]]s 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 boat]]s, such as the {{sclass2|Komar|missile boat|5}} and {{sclass2|Osa|missile boat|4}}es, 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 U.S. Navy proposed the PHM design as a NATO standard, with the program being led by the U.S. Navy, and an order placed for two prototypes in 1972.<ref name="Jenkins p1-2">Jenkins 2000, p. 1–2.</ref> The Italian Navy and the West 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.<ref name="jss75 p279-0">McLeavy 1975, pp. 279–280.</ref> The U.S. Navy planned to buy up to 30 PHMs, with 10 to be purchased by West Germany and four by Italy.<ref name="jss75 p279-0"/><ref name="Jenkins p2">Jenkins 2000, p. 2.</ref><ref name="Conways47 p625">Gardiner  and Chumbley 1995, p. 625.</ref>

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. [[United States Congress|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 {{convert|800|hp|kW|lk=on}} twin turbo-charged [[Mercedes-Benz]] [[diesel engine]]s when waterborne, using water jets (designed by [[Aerojet]]),<ref>[https://babel.hathitrust.org/cgi/pt?id=mdp.39015076086977;view=1up;seq=536 Testimony of Rear Adm. G. G. Halvorson], Fiscal year 1974 authorization for military procurement, pt. 4, p. 2392</ref> giving them a speed of {{convert|12|kn|lk=in}}. When foilborne, the ships were powered by a [[General Electric LM2500]] gas turbine and a very large water jet, giving them a speed of over {{convert|48|kn}}.

''Pegasus'' ships were well armed for their size, carrying two four-rack [[Boeing Harpoon|RGM-84 Harpoon]] [[anti-ship missile]]s and an [[Otobreda 76 mm|Oto Melara 76 mm]] gun. The Harpoons, specifically, were capable of sinking far larger ships at distances in excess of {{convert|60|nmi|km|lk=in}}. The West German version would have carried the [[Exocet|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 Integrated Defense Systems|Boeing]], in [[Seattle, Washington|Seattle]] at the Renton plant at the south end of [[Lake Washington]]. They were stationed at [[Naval Air Station Key West|NAS Key West]]. [[Principal contractor]]s, along with Boeing, were [[Sperry Corporation]] for MK 92 Mod 1 fire control system, [[Hollandse Signaalapparaten]] and Sperry Corp. (under license) for WM 28 fire control system, [[OTO-Melara]] for 76 mm gun, and [[NAVSEC]] for design support.<ref>[https://babel.hathitrust.org/cgi/pt?id=mdp.39015076086977;view=1up;seq=523 Testimony of Rear Adm. G. G. Halvorson], Fiscal year 1974 authorization for military procurement, pt. 4, p. 2379</ref>

The technology was first pioneered by {{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|2}} 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. {{cnspan|When in hydrofoil form, the ships would use 1000 gallons of fuel per hour. When in surface ship form, the ships would use 100 gallons of fuel per hour.<ref>{{cite web |title=Combat Ships: The Fast and the Furious |url=https://www.youtube.com/watch?v=ue3RNtrE7l8 |website=Youtube | date=10 April 2022 |publisher=Smithsonian Channel |access-date=18 April 2023}}</ref>|date=March 2023}}  USS ''Aries'' PHM-5 Hydrofoil Memorial, Inc. obtained ''Aries'' for rehabilitation as a memorial located on the Gasconade River in [[Gasconade, Missouri]] at {{coord|38|40|15|N|91|33|10|W|region:US}}. All other PHMs in the class were sold for scrap. In the early 2000s ''Gemini'' was converted into a yacht, but was abandoned by its owners in the 2010s and scrapped in 2017.<ref>{{cite web|url=http://www.starnewsonline.com/news/20141022/uss-gemini-yacht-on-cape-fear-sold-for-scrap-metal|website=StarNews Online|title=USS Gemini, yacht on Cape Fear, sold for scrap metal |accessdate=1 July 2016}}</ref>

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

==See also==
* [[Boeing hydrofoils]]
* {{USS|High Point|PCH-1}}
* {{USS|Plainview|AGEH-1}}
* {{HMCS|Bras d'Or|FHE 400}}, a Canadian hydrofoil intended for anti-submarine duties
* {{HMS|Speedy|P296}}, a [[Royal Navy]] [[Jetfoil]] [[mine countermeasure vessel]].
* [[Matka-class missile boat]], a class of Soviet PHM
* [[Sarancha-class missile boat]], a class of Soviet PHM
* {{sclass|Sparviero|patrol boat}}, a class of Italian PHM
* [[PHM Pegasus]], a videogame based on this class of vessels
* [[USS Flagstaff]]
* [[USS Tucumcari]]
* [[List of patrol vessels of the United States Navy]]
* [[Osprey-Class PTF]]

==References==
{{Reflist}}

* Gardiner, Robert and Stephen Chumbley. ''Conway's All The World's Fighting Ships 1947–1995''. Annapolis, Maryland, USA: Naval Institute Press, 1995. {{ISBN|1-55750-132-7}}.
* McLeavy, Roy. ''Jane's Surface Skimmers: Hovercraft and Hydrofoils 1975–76''. Jane's Yearbooks, 1975. {{ISBN|0 354 00525 1}}.
* Jenkins, George. [https://web.archive.org/web/20170817075536/http://www.foils.org/phmhist.pdf "Patrol Combatant Missile (Hydrofoil): PHM History 1973–1995"] (pdf).  ''Foils.com'', 1 November 2000. Retrieved 5 September 2012.

==External links==
{{Commons category|Pegasus class hydrofoil}}
* [https://web.archive.org/web/20141220120758/http://www.boeing.com/history/boeing/hydro.html Boeing page]
* [http://www.ussaries.org/ USS Aries PHM-5 Hydrofoil Memorial, Inc.] - [[Brunswick, Missouri]]

{{Pegasus class hydrofoil}}

[[Category:Pegasus-class hydrofoils| ]]
[[Category:Missile boat classes]]