Tapi-class corvette

In 1969, Thailand ordered from the United States a single small PF 103-class frigate, of which four examples, the Bayandor class, had been built for Iran in the 1960s, with a second example being ordered in 1971. For procurement purposes, they were allocated the US Navy hull numbers PF 107 and PF 108.^[2]

As built, single 3 inch/50 calibre Mk 34 automatic anti-aircraft guns were mounted fore and aft,^[2] each capable of firing 6.8 kg (15 lb) shells to a range of 13,400 m (14,600 yd) at a rate of 45 rounds per minute,^[3] backed up by a twin Bofors 40mm/L60 mount. Two triple Mark 32 torpedo tubes for anti-submarine torpedoes and a Hedgehog anti-submarine mortar comprised the ships' anti-submarine armament.^[2] AN/SPS-6 air-search radar and SQS-17 sonar comprised the ships' sensor suite.^[2]

The first ship, Tapi, was commissioned on 19 November 1971, with the second ship, Khirirat, following on 10 August 1974.^[1] Both ships were modernised during the 1980s, with the US 3-inch guns being replaced by a rapid fire OTO Melara 76 mm gun forward, and a Bofors 40mm/70 gun aft, with two single 20 mm cannon replaced the existing twin Bofors mount. The obsolete Hedgehog was removed, and the ships were fitted with new radar and sonar systems.^[2][1]

As of 2002, they were used for patrolling Thailand's Exclusive economic zone.^[1]

• Baker, A.D. (1998). The Naval Institute Guide to Combat Fleets of the World 1998–1999. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-111-4.
• Friedman, Norman (1997). The Naval Institute Guide to World Naval Weapon Systems 1997–1998. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-268-4.
• Gardiner, Robert; Chumbley, Stephen (1995). Conway's All The World's Fighting Ships 1947–1995. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-132-7.
• Saunders, Stephen (2002). Jane's Fighting Ships 2002–2003. Coulsdon, UK: Jane's Information Group. ISBN 0710624328.