The Defense Acquisition Program Administration (DAPA) announced on November 20th that it is officially commencing the performance upgrade program for the Republic of Korea Navy's Jangbogo-II (Son Won-il class) submarines, which displace 1,800 tons.

DAPA held the System Development Launch Meeting for the Jangbogo-II submarine performance improvement project at HD Hyundai Heavy Industries in Ulsan on the same day. The meeting, attended by the Navy, the Defense Agency for Technology and Quality (DTaQ), and development companies, focused on sharing the business plan, discussing detailed system development promotion plans, and coordination measures across different fields.

The Navy has been operating a total of nine Jangbogo-II class submarines since the lead ship, the Son Won-il, was deployed for operations in 2007. HD Hyundai Heavy Industries constructed vessels 1-3, 5, 7, and 9, while Hanwha Ocean (formerly Daewoo Shipbuilding & Marine Engineering) constructed vessels 4, 6, and 8. The Son Won-il class is armed with the domestically developed Haeseong-II cruise missile, which has a range of 1,000 kilometers and is capable of long-range precision striking against the enemy's core facilities.

DAPA plans to invest a total of 468.9 billion won by 2033 to complete the performance upgrade for three Jangbogo-II submarines. The project involves replacing the combat system and the existing towed array sonar with the latest equipment, and adding new systems such as mine avoidance sonar, flank array sonar, and a buoyant antenna.

The existing combat system and towed array sonar are aging equipment developed in the 1990s, with reduced performance that made effective response to potential enemy threats increasingly difficult. This comprehensive performance upgrade is expected to significantly enhance the submarine's operational capabilities, including detection, identification, and attack. DAPA anticipates that the application of a domestically developed combat system will also ensure stable subsequent logistics support, thereby contributing to the military's seamless execution of operations.

The diesel-powered Jangbogo-II (Son Won-il class) submarines are equipped with Air Independent Propulsion (AIP), allowing them to perform underwater operations for approximately two weeks without needing to surface. Measuring 65 meters in length and 6.3 meters in width, the Jangbogo-II submarine has a maximum speed of 20 knots (about 37 km/h). Armed with torpedoes, mines, and guided missiles, it is the Navy's main submarine capable of conducting anti-surface warfare, anti-submarine warfare, and offensive mine-laying missions.