Background
Pressure hull building process of KSS-III submarines
The design of the KSS-III was jointly designed by Daewoo Shipbuilding & Marine Engineering (now Hanwha Ocean) and Hyundai Heavy Industries (now HD Hyundai Heavy Industries) - two of South Korea's largest shipbuilding enterprises; preparations for the design began in 2007.[23][24] The KSS-III is the largest submarine built in Korea and the first submarine designed with domestic technology, unlike the KSS-II submarine (Son Won-il-class submarine) previously produced in cooperation with Howaldtswerke-Deutsche Werft (HDW).[25][26]
The Dosan Ahn Chang-ho class, the first 3,000-ton submarine designed through the KSS-III program, achieved a 76 percent localization rate, twice as high as the previously license-built KSS-II submarine. The development process adopted a design process using digital mock-up simulation for the first time in Korea, and the hull was made of HY-100 alloy steel to withstand high pressure of deep water. Although the size of the submarine is larger than that of the existing KSS-II submarine, the noise is minimized by applying non-acoustic stealth technologies such as acoustic anechoic coating and elastic mounts. The submarine's interior is made up of large and small pipes measuring 85 km in total length and has 127 types of acoustic and electronic equipment embedded in.[25][26]
The first vessel, ROKS Dosan Ahn Changho, of the KSS-III program was designed as a system development process using experimental technologies to demonstrate South Korea's independent submarine building capabilities, but the second, ROKS Ahn Mu, is the first submarine to be built and commissioned through an official mass production process. Ahn Mu successfully passed 125 items of builder test, 208 items of harbor acceptance test, and 90 items of sea acceptance test during the trial run process from January 2020 to April 2023. It also includes key features such as VHF marine communication system, passive linear array sonar, torpedo acoustic counter measure, underwater radiated noise level, electric propulsion motor, which are improved from the previous Dosan Ahn Changho.[27]