Hanwha Ocean has officially launched the Republic of Korea Navy’s first Dosan Ahn Chang-ho-class (KSS-III) Batch-II attack submarine, an important development in South Korea’s ambitions to establish a sophisticated undersea fleet. The submarine, named ROKS Jang Yeong-sil (SS-087), was inaugurated at Hanwha’s shipyard in Geoje-si, Gyeongsang, in the presence of high-ranking military and defense officials.
Seoul has emphasized that the 3,600-ton diesel-electric submarine will play a central role in bolstering the nation’s maritime defense capabilities and enhancing its responsiveness to security threats in the vicinity of the Korean Peninsula. As part of its integration into the naval forces, the South Korean navy plans to conduct extensive testing and evaluation of the Jang Yeong-sil, aiming for its official deployment by late 2027.
The Jang Yeong-sil is designed to be significantly more powerful and advanced than its predecessors in the KSS-III Batch-I series. Notable enhancements include the use of lithium-ion batteries that facilitate longer missions underwater, increased speed, and a lowered likelihood of detection by enemy forces. The submarine’s combat and sonar systems have been upgraded, improving target acquisition and engagement accuracy, whether against land or maritime threats.
Safety and operational resilience are also key features of the new submarine. It includes an auxiliary propulsion system that allows for continued maneuverability should the main propeller encounter any issues. Additionally, the incorporation of advanced noise and vibration reduction technologies enhances its stealth capabilities, making it less detectable to adversaries.
As for specifications, the KSS-III Batch-II system employs entirely domestically-sourced technology and components. The submarine measures 89 meters (292 feet) in length and 10 meters (33 feet) in beam, enabling it to achieve speeds of up to 20 knots (37 kilometers/23 miles per hour). Remarkably, it can operate for missions exceeding 20 days without surfacing, covering distances of around 10,000 nautical miles (18,520 kilometers/11,508 miles).
In terms of armament, the Jang Yeong-sil is equipped with submarine-launched ballistic missiles and land-attack cruise missiles, significantly enhancing South Korea’s undersea strike and deterrence capabilities. Looking ahead, the South Korean government plans to commission a total of up to nine KSS-III submarines throughout the 2030s, building on the three vessels from the KSS-III Batch-I that have already been incorporated into service between 2021 and 2024.
