Chungnam-class (FFX Batch III)

The Chungnam-class frigate, also designated as the Incheon-class Batch III, FFX-III, or FFG-III, is a class of guided-missile frigates built for the Republic of Korea Navy. The design is based on the preceding Daegu class, which developed from the Incheon class. The FFX Batch III is occasionally referred to as the Ulsan class, a name shared with both the predecessor class to the FFX program and the planned FFX Batch IV. The Republic of Korea Navy plans to acquire six vessels in this class, with construction split among Hyundai Heavy Industries, SK Oceanplant, and Hanwha Ocean.

The class features a combined diesel-electric or gas propulsion system driving two shafts. In terms of defensive capabilities, the vessels are designed to intercept up to eight incoming missiles simultaneously. A derivative of the design, designated HDF-4000TH, was offered by Hyundai Heavy Industries to the Royal Thai Navy. This export variant is configured with a fixed-phased array radar, Barak missiles for area and point defense, and Blue Spear anti-ship missiles.

Two ships of the class are active, two have been launched, and two are under construction. The lead ship, ROKS Chungnam (FFG-828), was built by Hyundai Heavy Industries, laid down in April 2022, launched in April 2023, and commissioned in December 2024. The second vessel, ROKS Gyeongbuk (FFG-829), was built by SK Oceanplant, where construction began with a steel-cutting ceremony in July 2023; the ship was laid down in April 2024, launched in June 2025, and commissioned in June 2026. SK Oceanplant also built the third and fourth vessels, ROKS Jeonnam (FFG-831) and ROKS Jeju (FFG-832), which have both been launched. The final two planned vessels, currently designated FFG-833 and FFG-835, are under construction by Hanwha Ocean with planned commissioning dates through 2028.