King Sejong the Great Class Destroyer

The King Sejong the Great class destroyers or also known as KD-III, are guided missile destroyers of the Republic of Korea Navy. The lead ship was launched 25 May 2007, sponsored by Kwon Yang-sook, the First Lady of the Republic of Korea at the time and was commissioned in December 2008. The second ship was commissioned in August 2010. As of 2010, the ROK Navy has committed itself to deploy three ships with an option for three more.

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, the KDX-III King Sejong the Great destroyers are by far 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.

King Sejong the Great Class Destroyer
Builders:	Hyundai Heavy Industries Daewoo Shipbuilding & Marine Engineering
Operators:	Republic of Korea Navy
Preceded by:	Chungmugong Yi Sun-sin class destroyer (KD-II)
Cost:	$923 million
General characteristics
Class and type:	Sejong the Great class destroyers
Displacement:	8,500 tons standard displacement 11,000 tons full load
Length:	165.9 m
Beam:	21.4 m
Draft:	6.25 m
Propulsion:	4 General Electric LM2500 COGAG; two shafts, 100,000 total shaft horsepower (75 MW)
Speed:	30+ knots (56+ km/h)
Range:	5,500 nautical miles (10,200 km)
Complement:	300-400 crew members
Sensors and processing systems:	AN/SPY-1D(V) multi-function radar AN/SPG-62 fire control radar DSQS-21BZ hull mounted sonar MTeQ towed array sonar system
Electronic warfare and decoys:	LIG Nex1 SLQ-200K Sonata electronic warfare suite
Armament:	1 x 5 inch (127mm/L62) Mk-45 Mod 4 naval gun 1 x 30 mm Goalkeeper CIWS 1 x RAM Block 1 CIWS 4 x 4 SSM-700K Hae Sung anti-ship missiles 80-cell Mk 41 VLS SM-2 Block IIIB/IV 48-cell K-VLS 32 x Hyunmoo III land attack cruise missiles 16 x K-ASROC Red Shark in (VLS) 2 x 3 K745 LW Blue Shark torpedoes
Aircraft carried:	• Hangar for two Super Lynx or SH-60 Seahawk, one more on landing pad

Armaments

Sejong the Great class destroyers' main gun is the 127mm/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 two 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 IIIC (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)

Capabilities

Sejong the Great class destroyers' are often compared to Arleigh Burke class and Atago class 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 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 and the Japanese Atago class destroyers. Another similarity to Arleigh Burke class 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.

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 the Sejong the Great. King Sejong the Great is the fourth king of the Joseon Dynasty of Korea. He is credited with the creation of the Korean alphabet, Hangul.