The ''Cheonghaejin'' class (

Hangul The Korean alphabet is the modern writing system for the Korean language. In North Korea, the alphabet is known as (), and in South Korea, it is known as (). The letters for the five basic consonants reflect the shape of the speech organs ...

: ;

Hanja Hanja (; ), alternatively spelled Hancha, are Chinese characters used to write the Korean language. After characters were introduced to Korea to write Literary Chinese, they were adapted to write Korean as early as the Gojoseon period. () ...

: ) is a

submarine rescue ship A submarine rescue ship is a surface support ship for submarine rescue and deep-sea salvage operations. Methods employed include the McCann Rescue Chamber, deep-submergence rescue vehicles (DSRV's) and diving operations. List of active su ...

class of the

Republic of Korea Navy The Republic of Korea Navy (ROKN; ), also known as the ROK Navy is the naval warfare service branch of the Republic of Korea Armed Forces, South Korean armed forces, responsible for naval and Amphibious warfare, amphibious operations. The South ...

. Only one ship has been built in the class, ROKS ''Cheonghaejin'' (ASR 21), in 1995. Its operations include rescuing trapped sailors in

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

s, naval operation support for submarines, underwater research and mapping support, and recovery of sunk vessels. It is equipped with a

deep submergence rescue vehicle A deep-submergence rescue vehicle (DSRV) is a type of deep-submergence vehicle used for rescue of personnel from disabled submarines and submersibles. While DSRV is the term most often used by the United States Navy, other nations have different ...

(DSRV) that operates up to , and a rescue chamber that holds up to nine people.

Design and description

The design for a

was first offered for export as the DW 4000R Koje class. One ship of the design was ordered in 1992 to support the

(ROKN)'s submarine fleet. The vessel is capable of providing

battery Battery or batterie most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source * Battery indicator, a device whic ...

charging, provisions, fuel, oxygen and water to ROKN submarines. The ship measured long with a beam of and a draught of . At

full load The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weig ...

, the ship displaces . The vessel is powered by a diesel-electric system comprising four

MAN A man is an adult male human. Before adulthood, a male child or adolescent is referred to as a boy. Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromosome from the f ...

Burmeister & Wain Burmeister & Wain was a large established Danish shipyard and leading diesel engine producer headquartered in Copenhagen, Denmark. Founded by two Danes and an Englishman, its earliest roots stretch back to 1846. Over its 150-year history, it g ...

16 V 28/32

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

s creating each and two electric motors, creating . These power the two shafts with

controllable pitch propeller Controllability is an important property of a control system and plays a crucial role in many regulation problems, such as the stabilization of unstable systems using feedback, tracking problems, obtaining optimal control strategies, or, simply p ...

s, three

bow thruster Manoeuvering thrusters (bow thrusters and stern thrusters) are transversal propulsion devices built into or mounted to either the Bow (watercraft), bow or stern (front or back, respectively) of a ship or boat to make it more manoeuvrable. Bow th ...

s and two stern thrusters. This gives the ship a maximum speed of and a range of at . The vessel is also equipped with shaped rudders and a

dynamic positioning system Dynamic positioning (DP) is a computer-controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompass ...

which all the ship to better maneuver at low speeds. The ship has a crew of 130 personnel. The submarine rescue ship is equipped with two 2,000 kW shaft generators and four 400 kW diesel generator sets that create a total of 5,600 kW of electric power. These are used to power two electrohydraulic telescoping cranes at the fore and an A-frame crane on the stern used to handle the assigned

deep submergence vehicle A deep-submergence vehicle (DSV) is a deep-diving crewed submersible that is self-propelled. Several navies operate vehicles that can be accurately described as DSVs. DSVs are commonly divided into two types: research DSVs, which are used for ex ...

(DSRV). The initial DSRV was capable of operating to a depth of . However, a new DSRV was assigned to the ''Cheonghaejin'' class in November 2008. ''DSAR-5'' is capable of operating up to . The DSRV measures long with a beam of and a draught of and has a crew of three. The DSRV can transport up to 16 people. Additional capabilities include a

diving bell A diving bell is a rigid chamber used to transport divers from the surface to depth and back in open water, usually for the purpose of performing underwater work. The most common types are the open-bottomed wet bell and the closed bell, which c ...

capable of transporting nine people and a

decompression chamber A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of ...

. The ''Cheonghaejin'' class has a

towing winch Towing is coupling two or more objects together so that they may be pulled by a designated power source or sources. The towing source may be a motorized land vehicle, vessel, animal, or human, and the load being anything that can be pulled. ...

and carries two landing craft vehicle personnel on

davit Boat suspended from Welin Quadrant davits; the boat is mechanically 'swung out' Gravity multi-pivot on Scandinavia'' file:Bossoir a gravité.jpg, Gravity Roller Davit file:Davits-starbrd.png, Gravity multi-pivot davit holding rescue vessel on ...

s for use as work boats. The ship has hull-mounted sonar and a landing platform for a light helicopter. The vessel is armed with six machine guns.

Ships in class

Construction and career

The only ship of the class, ''Cheonghaejin'', was ordered for construction by

Daewoo Daewoo ( ; ; ; ; literally "great universe" and a portmanteau of "''dae''" meaning great, and the given name of founder and chairman Kim Woo-choong) also known as the Daewoo Group, was a major South Korean chaebol (type of conglomerate) and aut ...

at their shipyard in Okpo. The vessel's

keel The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often ...

was

laid down Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship. Keel laying is one ...

in December 1994 and the ship was launched on 17 October 1995. ''Cheonghaejin'' was commissioned on 30 November 1996 and entered active service in March 1997. In 1998, ''Cheonghaejin'' salvaged a North Korean submarine. ''Cheonghaejin'' also recovered a North Korean semi-submersible vehicle from a depth of . In 2023, the vessel was ordered to recover sections of a rocket fired by North Korea into the

Yellow Sea The Yellow Sea, also known as the North Sea, is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. Names It is one of four ...

. The rocket lay deep.

Citations

References

* * * {{Republic of Korea Navy ships Auxiliary ships of the Republic of Korea Navy Submarine rescue ships Auxiliary search and rescue ship classes