KDDX-S is intended to replace the KDX II Chungmugong Yi Sun-sin-class destroyers of the ROK Navy
Xavier Vavasseur story with additional reporting by Eunhyuk Cha
One of the most discussed topics at MADEX 2023 was MUM-T (man, unmanned teaming), and Hanwha Ocean (known until recently as DSME) presented a new destroyer design known as “KDDX-S”. KDDX-S is designed to act as a mothership and play a key role in the MUM-T concept of the ROK Navy known as “Navy Sea Ghost”.
As its name infers, KDDX-S is based on DSME’s KDDX design proposal. Note however that DSME lost to rival HHI for the KDDX basic design. As previously reported by Naval News, South Korea’s DAPA selected HHI at the end of 2020 to carry out the basic design of the next generation destroyer of the Republic of Korea (ROK) Navy.
However Hanwha Ocean believes its KDDX design (which we covered at MADEX 2019) features many qualities which may be a strength for the upcoming KDDX-S competition. KDDX-S ships are set to replace the KDX II (Chungmugong Yi Sun-sin-class) destroyers. Six ships of the class are currently in service with the ROK Navy.
Talking to Naval News at MADEX 2023, Kyong-honn Min, Principal Engineer in the Naval & Special Ship Basic Design Team at Hanwha Ocean explained that the “S” in KDDX stands for “Smart”. He confirmed that the KDDX-S design is based on DSME’s KDDX design, although the hull form may be different.
Hanwha Ocean’s KDDX-S sits currently at 7,000 tons of displacement with a length of 145 meters, a width of 17.6 meters and a draft of 9.8 meters.
KDDX-S weapon and sensor systems
The new KDDX-S design features an inverted bow known to maximize hull speed while keeping the length of the hull reduced. The 5-inch main gun is encapsulated like the Zumwalt-class destroyer’s AGS (Advanced Gun System) to meet low RCS requirements. The model features a laser weapon system forward and two K-VLS zones: One forward of the bridge with 48 cells and one located amid-ship with just 4 cells (these may be the larger K-VLS II cells however, able to launch a land attack cruise missile).
The anti-ship missile launchers (2×4) located right behind the mast are enclosed inside the superstructure to maximize stealth. The missile canisters are raised right before launching the missiles (in a similar fashion to the NSM launchers fitted aboard Norway’s Skjold class corvettes). KDDX-S is fitted with lightweight torpedo launchers for anti-submarine warfare (as well as a Wildcat ASW helicopter).
For self-protection, the KDDX-S scale model on display at MADEX 2023 features two MASS chaff decoy launchers by Rheinmetall, two Korean anti-torpedo decoy launchers by LIG Nex1 and one CIWS-II by LIG Nex1 placed on top of the helicopter hangar.
The model also features the I-MAST integrated mast by Hanwha Systems already selected for the KDDX. The KDDX-S is set to feature EOTS and a towed array sonar too.
Drone Mothership
The destroyer features a dedicated cargo bay to accommodate, deploy and retrieve a wide range of “UxV” uncrewed systems: Unmanned Surface Vessels (USV), Unmanned Underwater Vehicles (UUV) and Vertical Take Off (VTOL) Unmanned Aerial Vehicles (UAV). The “UxV” area on the destroyer scale model showed the presence of two USV, two Camcopter S-100 type VTOL UAV, two XLUUV and a large RHIB. According to Kyong-honn Min, this area on the scale model was just to show the concept of KDDX-S as a mothership for MUM-T. The “UxV” area will change extensively as the design matures.
Work on KDDX-S started in 2019 with a feasibility study for the ROK Navy. Three alternatives were being looked. In 2023 one of the alternative was downselected to prepare for the KDDX-S development. Several key aspects of the vessel will be studied during this new phase: Pre-study of operational concept, stealth hull form, laser gun feasibility study, anti-drone system feasibility study, launch and recovery system for the “UxV”, command and constrol for the “UxV”…
The program will enter preliminary design phase in 2024. Naval News understands Hanwha Ocean will compete against HHI for the basic design contract to be awarded by DAPA. HHI wasn’t showcasing its KDDX-S design at MADEX 2023.
Our video coverage of KDDX-S at MADEX 2023:
