The ''Phutthayotfa Chulalok''-class frigates are two of forty-six s originally laid down for the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

as ocean escorts (formerly called

destroyer escort Destroyer escort (DE) was the United States Navy mid-20th-century classification for a warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships. Development of the destroyer escort was promoted by th ...

s), 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. The

Thai Navy The Royal Thai Navy ( Abrv: RTN, ทร.; , ) is the naval warfare force of Thailand. Established in 1906, it was modernised by the Admiral Prince Abhakara Kiartiwongse (1880–1923) who is known as the father of the Royal Navy. It has a str ...

acquired them between 1994 and 1996.

Description

The ''Phutthayotfa Chulalok'' class are

long overall Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also u ...

and at the waterline, with a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Radio beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially lo ...

of and a

draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...

of , at a standard

displacement Displacement may refer to: Physical sciences Mathematics and physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

of and at full load. The steam plant for these ships consists of two

Combustion Engineering Combustion Engineering (C-E) was a multi-national American-based engineering firm that developed nuclear steam supply power systems in the United States. Originally headquartered in New York City, C-E moved its corporate offices to Stamford, Connec ...

boilers each equipped with a high-pressure (supercharger) forced draught air supply system, with a plant working pressure of and superheat and rated at driving a Westinghouse geared turbine connected to a single

screw A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the screw head, head. The most common uses of screws are to hold objects together and there are many forms for a variety ...

. This gives them a speed of . As built, they were equipped with one /54 caliber Mark 42 gun forward, an eight-round ASROC launcher (with 16 missiles carried) abaft the gun and forward of the bridge, with four fixed Mark 32 anti-submarine torpedo tubes. A helicopter deck and hangar for operating the DASH drone helicopter was fitted aft. The helicopter facilities were expanded in the 1970s to accommodate the larger, crewed Kaman SH-2D Seasprite LAMP helicopter.

Service history

and were purchased by Thailand in 1996 and 1999. Thailand had initially leased ''Truett'' in 1994. Following refits and a service life extensions costing some $14 million each, ''Ouellet'' and ''Truett'' were commissioned by the Royal Thai Navy as ''Phutthaloetla Naphalai'' (FFG-462) and ''Phutthayotfa Chulalok'' (FFG-461). Both are still in active service. In 2013, it was reported that the ships of this class would be retired, ''

Phutthayotfa Chulalok Phutthayotfa Chulalok (born Thongduang; 20 March 1737 – 7 September 1809), also known by his regnal name Rama I, was the founder of the Rattanakosin Kingdom (now Thailand) and the first King of Siam from the reigning Chakri dynasty. He asce ...

'' in 2015, and ''

Phutthaloetla Naphalai Phutthaloetla Naphalai (born Chim; 24 February 1767 or 1768 – 21 July 1824), also known by his regnal name Rama II, was the second King of Siam from the Chakri dynasty, ruling from 1809 to 1824. In 1809, Itsarasunthon succeeded his father ...

'' in 2017.

Ships of the class

''Phutthayotfa Chulalok''

''Phutthayotfa Chulalok'' (). The ship is named after the first king of the

Chakri Dynasty The Chakri dynasty is the current reigning dynasty of the Thailand, Kingdom of Thailand. The head of the house is the Monarchy of Thailand, king, who is head of state. The family has ruled Thailand since the founding of the Rattanakosin era and ...

, King Phutthayotfa Chulaok the Great. The Royal Thai Navy first leased the ship from the US Navy after she was decommissioned on 30 July 1994. The ship was eventually purchased on 9 December 1999.

''Phutthaloetla Naphalai''

''Phutthaloetla Naphalai'' (). The ship is named after the second king of the

, King Phutthaloetla Naphalai The Royal Thai Navy purchased the ship from the US Navy after she was decommissioned on 6 August 1993. The ship subsequently underwent a US $14M refit at the Cascade General Shipyard,

Portland Portland most commonly refers to: *Portland, Oregon, the most populous city in the U.S. state of Oregon *Portland, Maine, the most populous city in the U.S. state of Maine *Isle of Portland, a tied island in the English Channel Portland may also r ...

, Oregon, and arrived in Thailand in 1998.

References

Bibliography

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External links

{{DEFAULTSORT:Phutthayotfa Chulaok class Ships built in Bridge City, Louisiana 1970 ships Royal Thai Navy ships Frigate classes