[23] The KSS-III initiative consists of the development of nine diesel-electric attack submarines, capable of firing submarine-launched ballistic missiles (SLBM), to be built in three batches, between 2014–2029.
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.
[27][28] 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.
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.
[34] The design further incorporates an indigenously-designed fuel-cell powered air-independent propulsion (AIP) module - which enables the submarine to conduct long-distance underwater operations for up to 20 days.
[41][42] According to DSME, the Batch-II series will be equipped with "a greater level of South Korean technology" - with over 80% of the submarine's parts to be domestically sourced.
[59] On 11 October 2019, South Korea's Defense Acquisition Program Administration (DAPA) contracted DSME to design and build the first Batch-II submarine - at an estimated cost KRW ₩1.11 trillion.
[63] At the 2019 convention of the "International Maritime Defense Industry Exhibition" (MADEX), held at Busan, South Korea, DSME unveiled the DSME-2000 - a 2,000 t (2,000 long tons), diesel-electric variant of the KSS-III, as an export-oriented design for foreign navies.
[66] The DSME-3000 was first displayed to the public at the 2021 convention of the "International Maritime Defense Industry Exhibition" (MADEX), held at Busan, South Korea.
[65] The DSME-3000 will be equipped with lithium-ion batteries and a fuel-cell powered AIP system, as on the KSS-III; however, the variant being offered to India lacks the K-VLS cells, which are standard on both Batch-I and Batch-II submarines being built for the Republic of Korea Navy.
[65] DSME entered the competition in April 2019 and was later shortlisted as a finalist, along with four other international shipyards - ThyssenKrupp Marine Systems (TKMS), Rubin Design Bureau, Navantia and Naval Group.