The Baleares class are a group of five frigate

Frigate

A frigate is any of several types of warship, the term having been used for ships of various sizes and roles over the last few centuries.In the 17th century, the term was used for any warship built for speed and maneuverability, the description often used being "frigate-built"...

s built for the Spanish navy

Spanish Navy

The Spanish Navy is the maritime branch of the Spanish Armed Forces, one of the oldest active naval forces in the world. The Armada is responsible for notable achievements in world history such as the discovery of Americas, the first world circumnavigation, and the discovery of a maritime path...

 in the 1970s. The ships are a modified version of the American Knox class frigate

Knox class frigate

Knox class frigates were United States Navy warships, originally laid down as ocean 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.A sub-class of the Knox class was built, commonly referred to as...

s. The key differences are the replacement of the Sea Sparrow PDMS and ASW helicopter facilities by Standard SAM

RIM-66 Standard

The RIM-66 Standard MR is a medium range surface-to-air missile originally developed for the United States Navy . The SM-1 was developed as a replacement for the RIM-2 Terrier and RIM-24 Tartar that were deployed in the 1950s on a variety of USN ships...

 and associated radars. They received a SPS-52B 3D search radar and one SPG-51 illuminator for the Standard SM-1 medium range SAM, fired from a Mk22 16-round single arm launcher. The SQS-26 long range LF sonar was replaced by a SQS-23G MF sonar, while two Mk25 tubes for Mk37 torpedoes

Mark 37 torpedo

The Mark 37 torpedo is a torpedo with electrical propulsion, developed for the US Navy after World War II. It entered service with the US Navy in the early 1950s, with over 3,300 produced. It was phased out of service with the US Navy during the 1970s, and the stockpiles were sold to foreign...

 were mounted in the transom. The SQS-35 variable depth sonar was maintained.

The five ships were upgraded several times during their service lives. They received a Spanish TRITAN combat data system and the EW suite was upgraded with Spanish equipment. Mk36 SROC decoy launchers were also added, as well as two quadruple Harpoon launchers amidships. Two Meroka CIWS

Meroka CIWS

The Meroka CIWS is a Spanish Navy 12 barrelled 20 mm CIWS, using twelve Oerlikon 20 mm/120 guns mounted in 2 rows of 6 guns each. The system's primary purpose is defence against anti-ship missiles, and other precision guided weapons. However it can also be employed against aircraft, ships...

gun system were also fitted. The old SQS-23G sonar was replaced by a modern DE-1160LF set built in Spain (a larger, lower frequency version of the SQS-56 sonar) and the Mk25 tubes were removed to allow for female crewmember berthing.

The ships have recently been retired, in order to assume the costs of the F100 frigates (the Álvaro de Bazán class), which will replace the Baleares class on a one to one basis.

Ships in class

All ships were built in Ferrol. They made up the 31 Escort Squadron, based in Ferrol. The Spanish Navy adopted the Standard SAM, what gave the class an excellent anti-air (A/A) capacity, which the American Knox class lacked.

Ship	Launched	Commissioned	Status
F72 Andalucia	30 March 1971	23 May 1974	Decommissioned 2005
F74 Asturias	13 March 1972	2 December 1975	Decommissioned June 30, 2009
F71 Baleares	20 August 1970	24 September 1973	Decommissioned 2004
F73 Cataluna	3 November 1971	16 January 1975	Decommissioned 2004
F75 Extremadura	21 November 1972	10 November 1976	Decommissioned 2006