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.
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.
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.
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.
|Ship Name||Hull No.||Builder||Commission–|
|Knox||FF-1052||Todd, Seattle||1969–1992||Sunk as target|
|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|
|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)|
|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)|
|Downes||FF-1070||Todd, Seattle||1971–1992||Sunk as target|
|Badger||FF-1071||Todd, San Pedro||1970–1991||Sunk as target|
|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)|