The Sejong the Great-class destroyers, also known as KDX-III, are three guided missile destroyers of the Republic of Korea Navy. The ROKN has deployed three ships with an option for three more which was taken up in December 2013. Hereby KDX-3, which has the experimental meaning, is no longer used, and now it has been called KD-3.
The ship features the Aegis Combat System combined with AN/SPY-1D multi-function radar antennae. The Sejong the Great class is the third phase of the South Korean navy's Korean Destroyer eXperimental program, a substantial shipbuilding program, which is geared toward enhancing ROKN's ability to successfully defend the maritime areas around South 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 Sejong the Great destroyers are by far the largest destroyers in the South Korean Navy, and indeed are larger than most destroyers in the navies of other countries. and built slightly bulkier and heavier than s or s to accommodate 32 more missiles. As such, some analysts believe that this class of ships is more appropriately termed a class of cruisers rather than destroyers. KDX-III are currently the largest ships to carry the Aegis combat system.
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 other 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. Block IIIB has added infrared induction mode to Block IIIA, improving cruise missile interception capability. Anti-submarine warfare armaments consists of both K-ASROC Hong Sang-uh anti-submarine rockets which has same form to the U.S. ASROC. and 32 K745 LW Cheong Sang-uh torpedoes. Anti-ship capability is provided by 16 SSM-700K Hae Sung long-range anti-ship missile, each with performance similar to the U.S. Harpoon. It is equipped on a navy ship that is built after the late KD-2 class destroyer. Land-attack capability is provided by the recently developed Hyunmoo-3C cruise missile, which has similar to the U.S. Tomahawk. Missile batteries
The 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 have a capacity of 128 missiles, as opposed to 96 on the Arleigh Burke class and the Japanese Atago-class destroyers. The Sejong the Great class is thus one of the most heavily armed ships in the world, with even greater missile capacity than the Chinese People's Liberation Army NavyType 055 destroyer, or the U.S. Navy Ticonderoga-class guided missile cruiser, and considering only surface ships is surpassed only by the with 352 missiles. The four American Ohio-class submarines converted to guided-missile configuration carry 154 cruise missiles each. 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 s. These destroyers have the capability to track and monitor any missile launched from anywhere from North Korea. This capability was demonstrated by the tracking of a North Korean missile in April 2009.
BMD
In August 2016, press reports revealed that South Korea was considering adding the SM-3 interceptor to its Sejong the Great-class ships to enable them to perform ballistic missile defense in response to North Korean efforts to bolster offensive missile capabilities. This comes just months after the U.S. decision to deploy the THAAD missile interceptor system on mainland South Korea. The addition of SM-3s to the ships may require software and computer hardware upgrades. The following month, Aegis manufacturer Lockheed Martin confirmed the next three Sejong the Great vessels will be capable of performing "integrated air and missile defense" to supplement U.S. Army ground-based missile interceptors on the peninsula, likely being outfitted with the SM-3. While the first three destroyers are fitted with Aegis Baseline 7 based on older proprietary computers that can't carry out IAMD operations, the following three will be fitted with the Baseline 9 version of the Aegis Combat System that combines modern computing architecture to allow the AN/SPY-1D radar to perform air warfare and BMD missions at the same time.
Super Computer
It uses RedHawk Linux as OS.
Ships in the class
For reference, The annual maintenance cost per ship is 51.4 billion. On 10 December 2013, the ROKN confirmed ordering three more vessels on the same class. On 10 October 2019, Hyundai heavy industry signed a deal to build the first of the three, 170m long, KDX-III batch 2, Aegis destroyers for the Republic of Korea Navy. The guide ship will be delivered in November 2024.
