The South Korean shipyard SK Oceanplant recently carried out the launching of the third Ulsan-class FFX Batch-III anti-submarine frigate, named ROKS Jeonnam (FFG-831), continuing the schedule of the program aimed at modernizing the South Korean Navy’s (ROKN) medium escort fleet. The ceremony, held on November 25, took place at the shipyard’s facilities in Busan, marking a new advance in the construction of the six-unit batch planned by the Defense Acquisition Program Administration (DAPA).
According to information released by DAPA, ROKS Jeonnam will now begin a phase that will include work with the armament, systems integration, and sea trials that will extend over the coming months before its final delivery to the ROKN. At this point it is relevant to mention that these frigates constitute the core of South Korea’s new generation of anti-submarine escorts, with improvements in sensors, combat systems, and warfare capabilities in littoral and oceanic environments.
A program that advances
The launching of the new frigate for the South Korean Navy adds to the previous progress of the FFX Batch-III program, which will replace the older frigates (FF) and patrol combat corvettes (PCC). On this matter, the first unit, named ROKS Chungnam (FFG-828), was officially delivered to the South Korean Navy in December 2024, becoming the first Batch-III frigate to enter operational service. Meanwhile, the second unit, ROKS Gyeongbuk (FFG-829), was launched in July 2025. The latter had begun construction in 2021, followed by keel laying in 2023 and hull assembly in 2024.
With a displacement of 3,600 tons, these new frigates—129 meters in length and 14.8 meters in beam—are equipped with a 127 mm gun, anti-ship, land-attack, and anti-air missiles, as well as long-range anti-submarine torpedoes, also highlighting the presence of a hybrid propulsion system employed in the Batch-II frigates (Daegu class), which minimizes radiated underwater noise.
In addition to this, the Batch-III class frigates also have an integrated mast, which houses advanced detection technologies such as a new locally developed AESA radar, an advanced infrared search and tracking system (IRST), and the electro-optical tracking system (EOTS), which assist the ship and its crew in detecting and identifying threats.
Toward the next step: the FFX Batch-IV design phase
In parallel with the progress of the current batch, South Korea is already working on the preliminary design of the future FFX Batch-IV frigates, a project that aims to integrate structural improvements, greater automation, and a new-generation combat system. DAPA expects to complete the design phase in the coming years, with construction of the first hull to begin toward the end of the decade.
According to information released at the beginning of 2025, the future Batch-IV units will incorporate: improvements in acoustic and stealth signature; an increase in K-VLS vertical launch capacity; integration of new surface-to-surface and anti-air missiles; advances in hybrid or energy-efficient propulsion; and greater capacity to operate embarked UAVs.
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