Knox class frigates were United States Navy ships, originally laid down as ocean escorts (formerly called destroyer escorts), but were all redesignated as frigates on 30 June 1975 in the USN 1975 ship reclassification and their hull designation changed from DE to FF.

History

The 46 ships of the Knox class were the largest, last and most numerous of the US Navy’s second-generation ASW escorts. The lead ship of the class was the USS Knox (DE-1052), laid down October 5, 1965 and commissioned April 12, 1969, at Todd Shipyards in Seattle. Planned as the follow-on to the twin 5-inch gun armed Garcia class frigates and the Tarter missile-equipped Brooke class frigates, their initial design incorporated the prior classes’ pressure-fired boilers (the design later was changed to conventional 1200 psi boilers) in a similar-sized hull designed around the massive bow-mounted AN/SQS-26 sonar.

Ten ships were authorized in FY 1964, sixteen in 1965 and ten each for FYs 1966, ’67 and ’68; six were canceled in 1968 and four more in 1969. They were built in four different shipyards and were originally commissioned as destroyer escorts (DEs) 1052–97 in 1969–74, they were redesignated as frigates (FF) on 30 June 1975.

The Knox class was the Navy’s last destroyer-type design with a steam powerplant.

Due to their unequal comparison (large size with low speed and a single screw and 5inch gun) destroyers then in service they became known to a generation of destroyermen as “McNamara’s Folly.”

These ships were retired with the end of the Cold War and the removal of the need for an advanced ASW capability. By 1994 all ships of this class had been retired from the US Navy, although some remain in service with foreign nations such as Egypt, Taiwan, Thailand, Turkey and Mexico.

Description

These ships were designed primarily as antisubmarine (ASW) platforms. They each had AN/SQS-26 hull-mounted sonar manufactured by General Electric and capable of active echo ranging in the 3.2 kHz range. The active modes of operation included omni-directional, phased directional, bottom bounce, and convergence zone. The battle displays included A and B scans. There was also a "Unit 31" chart readout display capable of long-distance passive detection, often well beyond the ranges capable of the surface search radar. The frigates were also equipped with an AN/AQS-35V Independent Variable Depth Sonar (IVDS) manufactured by EDO Corporation of College Point, NY, operating actively in the 13 kHz range with dual Planned Position Indicator (PPI) battle displays. The IVDS' sonar transducers were packaged within a 2 ton fiberglass-enclosed "fish" containing the sonar array and a gyro-compass/sensor package launched by the massive 13V Hoist from a stern compartment, located just beneath the main deck, to depths of up to . The IVDS could take advantage of water layer temperature conditions in close-range (less than 20,000 yard) submarine detection, tracking and fire-control.

At 4,200 metric tons (4,130 tons), with a length of 438 feet (133.5 metres)and a beam of 47 feet (14.3 m), they are driven by a single screw geared turbine developing 35,000 shaft horsepower (26 MW), giving them a speed of . The steam plant for these ships consists of two Combustion Engineering or Babcock & Wilcox "D" type boilers, each equipped with a high-pressure (supercharger) forced draught air supply system, allowing a plant working pressure of 1,200 PSI and 1000 °F superheat. This design allows fast acceleration, crucial while prosecuting a submarine attack. They are equipped with one 5 in (127 mm) 54 caliber Mark 42 gun forward, an ASROC abaft the gun and forward of the bridge. Since they are single purpose platforms their surface defense capability is nominal; however they do mount Harpoon missiles and Mk-46 torpedoes. The aft weapons point was originally outfitted with Mk 25 basic point defense missile systems (BPDMS) for launching Sea Sparrow missiles. These were eventually refitted with a 20 millimetre Phalanx CIWS. They are equipped with a helicopter hangar aft.

Chi Yang Class

In the 1990s the US agreed to transfer 8 Knox-class Frigates to the Republic of China (Taiwan)'s Navy (ROCN). The ROCN planned to upgrade these ships with new air defense, anti-submarine, and electronic warfare capabilities, including new radar, towed active sonar, CIWS guns, VL air defense missiles, active/passive electronic warfare systems, etc. However, due to budget considerations and acquisition of newer ships, only few upgrades have actually been implemented. These frigates were named Chi Yang Class and assigned to the ROCN 168 Patrol Squadron.

By 2005 the ROCN had removed several systems from the retired Gearing-class upgraded WWII-vintage destroyers and transferred them to the Chi Yang Class FFG. These systems include SM-1MR standard missile in box launchers, H-930 modular combat system, and DA-09 air/surface search radar (with speculations that the Mk 75 76/62 rapid-fire gun might also replace the older Mk 42 127 mm/5" gun in the future). Each Chi Yang class frigate has 10 SM-1 missiles installed in 2 x forward twin box launchers on top of the helicopter hangar, and 2 x triple box launchers installed between the stack and the hangar, pointing to port and starboard.

The anti-submarine capability of the Chi Yang class FFG is provided by its SQS-26 bow-mounted sonar, SQS-35(v) VDS, SQR-18(v)1 passive TAS, MD500 ASW helicopter, Mk-16 8-cel Harpoon/ASROC box launcher, and 4 x Mk.46 324 mm torpedoes. While on ASW patrol, the frigate will carry 2 x Harpoon SSM and 6 x ASROC's in its Mk-16 box launcher.

Units

Ship Name	Hull No.	Builder	Commission– Decommission	Fate	Link
Knox	FF-1052	Todd, Seattle	1969–1992	Sunk as target
Roark	FF-1053	Todd, Seattle	1969–1991	Scrapped
Gray	FF-1054	Todd, Seattle	1970–1991	Scrapped
Hepburn	FF-1055	Todd, San Pedro	1969–1991	Sunk as target
Connole	FF-1056	Avondale	1969–1992	To Greece, renamed Epirus (F-456)
Rathburne	FF-1057	Lockheed	1970–1992	Sunk as target
Meyerkord	FF-1058	Todd, San Pedro	1969–1991	Scrapped
W. S. Sims	FF-1059	Avondale	1970–1991	Grant aid to Turkey as parts hulk
Lang	FF-1060	Todd, San Pedro	1970–1991	Scrapped
Patterson	FF-1061	Avondale	1970–1991	Scrapped
Whipple	FF-1062	Todd, Seattle	1970–1992	To Mexico, renamed Almirante Francisco Javier Mina (F-214)
Reasoner	FF-1063	Lockheed	1971–1993	To Turkey, renamed Kocatepe (F-252)
Lockwood	FF-1064	Todd, Seattle	1970–1993	Scrapped
Stein	FF-1065	Lockheed	1972–1992	To Mexico, renamed Ignacio Allende (F-211)
Marvin Shields	FF-1066	Todd, Seattle	1971–1992	To Mexico, renamed Mariano Abasolo (F-212)
Francis Hammond	FF-1067	Todd, San Pedro	1971–1992	Scrapped
Vreeland	FF-1068	Avondale	1970–1992	To Greece, renamed Makedonia (F-458)
Bagley	FF-1069	Lockheed	1972–1991	Scrapped
Downes	FF-1070	Todd, Seattle	1971–1992	Sunk as target
Badger	FF-1071	Todd, San Pedro	1970–1991	Sunk as target
Blakely	FF-1072	Avondale	1970–1991	Scrapped
Robert E. Peary	FF-1073	Lockheed	1972–1992	To Taiwan, renamed Chih Yang (FF-932)
Harold E. Holt	FF-1074	Todd, San Pedro	1971–1992	Sunk as target
Trippe	FF-1075	Avondale	1970–1992	To Greece, renamed Thraki (F-457)
Fanning	FF-1076	Todd, San Pedro	1971–1993	To Turkey, renamed Adatepe (F-251)
Ouellet	FF-1077	Avondale	1970–1993	To Thailand, renamed HTMS. Phutthaloetla Naphalai (FFG 462)
Joseph Hewes	FF-1078	Avondale	1971–1994	To Taiwan, renamed Lan Yang (FF-935)
Bowen	FF-1079	Avondale	1971–1994	To Turkey, renamed Akdeniz (F-257)
Paul	FF-1080	Avondale	1971–1992	To Turkey as parts hulk
Aylwin	FF-1081	Avondale	1971–1992	To Taiwan, renamed Ning Yang (FF-938)
Elmer Montgomery	FF-1082	Avondale	1971–1993	To Turkey as parts hulk
Cook	FF-1083	Avondale	1971–1992	To Taiwan, renamed Hae Yang (FF-936)
McCandless	FF-1084	Avondale	1972–1994	To Turkey, renamed Trakya (F-257)
Donald B. Beary	FF-1085	Avondale	1972–1994	To Turkey, renamed Karadeniz (F-255)
Brewton	FF-1086	Avondale	1972–1992	To Taiwan, renamed Fong Yang (FF-933)
Kirk	FF-1087	Avondale	1972–1993	To Taiwan, renamed Fen Yang (FF-934)
Barbey	FF-1088	Avondale	1972–1992	To Taiwan, renamed Hwai Yang (FF-937)
Jesse L. Brown	FF-1089	Avondale	1973–1994	To Egypt, renamed Dumyat (F961)
Ainsworth	FF-1090	Avondale	1973–1994	To Turkey, renamed Ege (F-256)
Miller	FF-1091	Avondale	1973–1991	To Turkey as parts hulk
Thomas C. Hart	FF-1092	Avondale	1973–1993	To Turkey, renamed Zafer (F-253)
Capodanno	FF-1093	Avondale	1973–1993	To Turkey, renamed Mauvenet (F-250)
Pharris	FF-1094	Avondale	1974–1992	To Mexico, renamed ARM Guadalupe Victoria(F-213)
Truett	FF-1095	Avondale	1974–1994	To Thailand, renamed HTMS. Phutthayotfa Chulalok (FFG 461)
Valdez	FF-1096	Avondale	1974–1991	To Taiwan, renamed Ki Yang (FF-939)
Moinester	FF-1097	Avondale	1974–1994	To Egypt, renamed Rasheed (F.962)

References

External links

• Knox-class frigates at Destroyer History Foundation
• Global Security
• Federation of American Scientists
• USS Brewton FF-1086 Home Page