General Facts

TYPE
Frigate

ORIGIN
United States

NICKNAMES
FF-1052 class (first pennant number)
Damyat class (Egyptian service
Ignacio Allende class (Mexican service)
Baleares class (Spanish production)
Chi Yang class (Taiwanese service)
Phutthayotfa Chulalok class (Thai service)
Muavenet class (Turkish service)

DESIGNED
Early 1960's

DESIGNER
Unknown

PRODUCTION
1965 - 1974 (US production)
1969 - 1976 (Spanish production

PRODUCERS
Spain - Bazan
United States - Avondale Shipyard
United States - Lockheed Shipbuilding
United States - Todd Shipyard

QUANTITY
A total of 46 produced in the USA and 5 in Spain

UNIT COST
Unknown

CHARACTERISTICS
Good ASW armament
Roomy and ergonomic for crews
Limited offensive armament
Limited speed
Very large and heavy
Limited air defence

Introduction

The Knox class is a frigate of US origin. It was developed in the 1960s the serve alongside older post WW2 era destroyers as anti-submarine escort. At first it was designated a destroyer escort, but was later redesignated as a frigate.

Design

The design is based on the older Garcia class ASW frigate. The Knox has a classic Cold War frigate layout with cannon and ASROC launcher on the bow, superstructure with funnel acting as sensor mast in the middle and helicopter deck and hanger at the rear. The Knox was the last US destroyer design with steam powerplant.

Firepower

The Knox class is fitted with a single 127mm dual purpose Mk 42 cannon. The main armament is the 8-round Mk 16 ASROC launcher for ASROC anti-submarine and Harpoon anti-ship missiles. Additional ASW capability exists in the form of two twin launchers for Mk 44 and Mk 46 torpedoes. Short range air defense is provided by RIM-7 Sea Sparrow missiles, which were later replaced by a Phalanx CIWS. The helicopter deck allows for a single SH-2 Seasprite ASW helicopter.

Electronics

The sensor package consists of a AN/SPS-10 and AN/SPS-67 surface search radars and an AN/SPS-40 2D air search radar. For ASW duties dthe Knox relies on an AN/SQS-26 bow mounted low frequency active/passive sonar, an AN/SQR-18 towed array sonar and SH-2 Seasprite helicopter. Fire control is carried out by the AN/SPG-53 gun fire control system.

Mobility

The propulsion system consist of once Westinghouse steam turbine and two Babcock & Wilcox boilers. The total power production is 35.000 shp which powers a single shaft. The maximum speed is over 27 knots.

Users

The Knox class was produced in large quantities with the main user being the United States. Five modified ships were built in Spain. Many Knox class frigates ended up in foreign navies as the Knox class was replaced by the Oliver Hazard Perry in US service.

Knox class

The Knox class is the original and most produced variant of the Knox class. Over time the Sea Sparrow launcher was replace with a Phalanx CIWS. A sub class known as the Hewes class was developed. This featured a different arrangement of the officers quarters to allow for a flag staff to be carried to act as a flagship.

Baleares class

The Baleares class is a batch of 5 Knox class frigates produced under license in Spain. This class differs in having the Sea Sparrow system replaced by Standard SM-1MR missiles and associated targeting equipment. Additionally the lightweight Mk 46 torpedoes are replaced with Mk 37 heavyweight torpedoes.

Chi Yang class

The Chi Yang class refers to the Knox class in Taiwanese service. A total of 8 second hand Knox class were transferred to Taiwan. These were to be extensively upgraded, but only minor upgrades were carried out due to budget cuts. Later components were added from retired upgraded Gearing class destroyers, including SM-1MR missiles, H-930 modular combat system and DA-08 air and surface search radar.