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Three units are being built by Hyundai Heavy Industries and Daewoo Shipbuilding & Marine Engineering. The destroyer class is also referred to as KDX-III.
The lead ship in its class, Sejong the Great (DDG 991), was launched in May 2007. The destroyer was commissioned in December 2008. The second destroyer, Yulgok Yi I (DDG 992), was launched in November 2008 and delivered in September 2010.
The vessel entered service with the ROKN in June 2011. The third destroyer, Seoae Ryu Seong-ryong (DDG 993), was launched in March 2011. It is scheduled for commission in 2012.
Background
The ship features the Aegis Combat System (Baseline 7 Phase 1) combined with AN/SPY-1D multi-function radar antennae.
The Sejong the Great class is the third phase of the Republic of Korea Navy's Korean Destroyer eXperimental (KDX) program, a substantial shipbuilding program, which is geared toward enhancing ROKN's ability to successfully defend the maritime areas around Korea from various modes of threats as well as becoming a blue-water navy. At 8,500 tons standard displacement and 11,000 tons full load,overall length of 165m, beam of 21m and draft of 6m,the KDX-III Sejong the Great destroyers are the largest destroyers in the Republic of Korea Navy,and built slightly bulkier and heavier than Arleigh Burke-class destroyers or Atago-class destroyers to accommodate 32 more missiles. KDX-III are currently the largest surface warfare ships to carry the Aegis combat system.
Missions
Sejong the Great Class destroyers are deployed in conventional naval warfare, anti-submarine warfare and anti-air warfare operations.
The destroyer conducts accurate strikes on the main enemy targets, and can protect mobile and convoy fleets from enemy aircraft and guided missiles.
It also supports the MASOC (Maritime Air Support Operation Centre) which controls all tactical aircraft operating on the sea.
The KDX-III destroyers allow the ROKN to protect Korean waters from air, surface, and subsurface threats.
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| Sejong the Great Class (Sejongdaewang Class) destroyers are armed with Chung Sang Eo (Blue Shark) torpedoes. |
Armaments
Sejong the Great-class destroyers' main gun is the 127 mm/L62 Mk. 45 Mod 4 naval gun, an improved version of the same gun used on other warships from several foreign nations. Point-defense armaments include one 30 mm Goalkeeper CIWS and a RIM-116 Rolling Airframe Missile Block 1 21-round launcher, the first Aegis platform to carry RAM.Anti-aircraft armament consists of SM-2 Block IIIA and IIIB in 80-cell VLS. Anti-submarine warfare armaments consists of both K-ASROC Hong Sahng-uh (Red Shark) anti-submarine rockets and 32 K745 LW Cheong Sahng-uh (Blue Shark) torpedoes. Anti-ship capability is provided by 16 SSM-700K Hae Sung (Sea Star) long-range anti-ship missile, each with performance similar to the U.S. Harpoon. Land-attack capability is provided by the recently developed Hyunmoo-3C (Guardian of the Northern Sky) cruise missile, which is similar to the U.S. Tomahawk.
Missile batteries
VLS: 128 cell
Mk 41 VLS 48 cell (Fwd)
Mk 41 VLS 32 cell (Aft)
K-VLS 48 cell (Aft)
Anti-ship missile launchers: 16
Command and control
KDX-III destroyers are equipped with the Aegis combat system developed by Lockheed Martin. The Aegis system consists of SPY-1 radar and other components including SPY-1D (V) transmitter and MK 99 fire control system.
The radar acquires and tracks multiple targets such as aircraft and missiles.
This system, integrated with the MK 41 vertical launching system, delivers missiles against multiple threats in different attack scenarios. It can be used as an integrated single ship system and in a ship-to-ship network.
In July 2010, the Sejong the Great (DDG 991) successfully completed the combat system ship qualification trials (CSSQT) at the Pacific Missile Range Facility, off the Hawaiian island of Kauai.
Sensors / radars
The AN/SPY-1D multifunction radar and four antenna arrays are housed in a single deck house. The ship is also equipped with AN/SPG-62 I/J band fire control radar, Atlas Elektronik bow-mounted DSQS-21 BZ-M sonar and MTeQ towed array sonar system.
Helicopter system
The KDX-III destroyers have a stern helicopter deck to support the operations of two Westland Lynx Mk 99 ASW helicopters. Hangar facilities are provided for the helicopters.
Propulsion
Sejong the Great Class destroyers are equipped with a combined gas turbine (COGAG) propulsion system.
Four General Electric LM2500 gas turbines driving the two shafts provide a total power output of 75MW.
The ship systems are powered by three Rolls-Royce AG9140RF gas turbine generator sets. The propulsion system provides a top speed of 30kt and a maximum range of 5,500nm at 20kt.
Capabilities
Sejong the Great-class destroyers' are often compared to the Arleigh Burke and Atago classes because they utilize the AN/SPY-1 multi-function radar, have similar propulsion and capabilities. One notable difference between the Sejong the Great-class ships and Arleigh Burkes is the number of VLS cells. Destroyers of the Sejong the Great class will have a capacity of 128 missiles, as opposed to 96 on the Arleigh Burke class (although ships in the Arleigh Burke class have the capability to quad-pack 4 ESSM missiles into one launch cell, greatly increasing armament) and the Japanese Atago-class destroyers. The Sejong the Great class is thus one of the most heavily armed ships in the world second only to the Kirov-class battlecruiser with 352 missiles. Another similarity to Arleigh Burke Flight IIA and Atago-class destroyers is the presence of full facilities for two helicopters, a feature missing from earlier Arleigh Burke and Kongō-class destroyers.
Three of these destroyers have, according to South Korean newspaper Chosun Ilbo, the capability to "track and monitor any missile launched from anywhere from the North." This capability was demonstrated by the tracking of a North Korean missile in April 2009.
Hull names
On April 20, 2007, Chief of Naval Operations of the Republic of Korea Navy announced that the lead ship of KDX-III class destroyers will be referred as Sejong the Great. Sejong the Great (Hangul: 세종대왕) is the fourth king of the Joseon Dynasty of Korea. He is credited with the creation of the Korean alphabet, Hangul.