The Khamronsin-class corvettes are three corvettes constructed for the Royal Thai Navy in the late 1980s. Based on a British design, all three ships were built in Thailand. A fourth vessel, constructed to a modified design, was built for the Thai Police and was the first to enter service in 1992. The three Khamrosin-class corvettes commissioned in 1992 and remain in service.

The three Khamronsin-class corvettes are based on the British Vosper Thornycroft Province design that was the basis for the Omani Dhofar class with increased spacing between the frames, increasing the length of the vessels.^[1][2] The vessels have a full load displacement of 630 tonnes (620 long tons).^{[2][lower-alpha 1]} The corvettes measure 62 metres (203 ft 5 in) long overall and 56.4 m (185 ft 0 in) at the waterline with a beam of 8.2 m (26 ft 11 in) and a draught of 2.5 m (8 ft 2 in). The Khamronsin class is propelled by two Kamewha controllable pitch propellers, each on their own shaft, powered by two MTU 12V 1163 TB93 diesel engines rated at 5,600 kilowatts (7,500 bhp). The vessels have a maximum speed of 25 knots (46 km/h; 29 mph) and a range of 2,500 nautical miles (4,600 km; 2,900 mi) at 15 knots (28 km/h; 17 mph).^[1][2] The corvettes have a complement of 6 officers and 51 enlisted.^[2]

The class is equipped with Plessey Nautis P combat data system and the British Aerospace Sea Archer 1A Mod 2 optronic gun control fire system (GCFS). They mount the Plessey AWS 4 air/surface search radar and the Atlas Elektronik DSQS-21C hull-mounted sonar. The Khamronsin class is armed with one OTO Melara 76 mm (3 in)/62 Mod 7 gun mounted forward and twin-mounted Breda 30 mm (1.2 in)/70 guns atop the aft superstructure. The corvettes also mount two triple Plessey PMW49A torpedo tubes for Sting Ray torpedoes and two 12.7 mm (0.50 in) machine guns. A Mk.6 depth charge launcher and naval mines can also be installed aboard the ships.^[2]

The first two Royal Thai Navy corvettes were ordered on 29 September 1987 from Ital Thai Marine at their yard in Bangkok, Thailand with aid to construct a third at the Bangkok Naval Dockyard.^[1][2] The first two vessels were laid down on 15 March 1988, one in each yard. The third ship was laid down at Ital Thai Marine's yard on 20 April. Longlom was launched on 8 August 1989 and Kamronsin on 15 August.^[2] Srinakarin, the fourth vessel, was ordered by the police in September 1989 from the Ital Thai Marine yard. The vessel's yard number was 82.^[3][4] Srinakarin was the first to enter service in April 1992. Kamronsin was the first naval version to commission on 29 July 1992, followed by Thayanchon on 5 September and Longlom on 2 October.^[2] All four ships are in service.