Asia Defense

South Korea’s First-of-Class KSS-III Attack Sub Begins Sea Trials

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Asia Defense

South Korea’s First-of-Class KSS-III Attack Sub Begins Sea Trials

South Korea’s newest diesel-electric attack sub is expected to be delivered to the Republic of Korea Navy by 2020.

South Korea’s First-of-Class KSS-III Attack Sub Begins Sea Trials
Credit: Republic of Korea Navy

South Korean shipmaker Daewoo Shipbuilding and Marine Engineering (DSME) has begun initial sea trials of the first of a planned fleet of nine 3,000-ton indigenously designed KSS-III (JangbogoIII-class) diesel-electric attack submarines (SSKs) this month.

Sea trials of the first-of-class Dosan Ahn Chang-ho began last week, an industry source confirmed with IHS Jane’s. According to the source, these include tests of the SSKs propulsion systems and steering equipment, next to others.

The initial set of builder sea trials can take up to 24 months, although the Republic of Korea Navy (ROKN) is expecting the 83.3-meter-long and 9.6-meter-wide SSK to be delivered by the end of next year.

Work on the SSK began in May 2016, punctuated by various delays due to construction and development problems, as well as logistical issues. The Dosan Ahn Chang-ho was launched in September 2018 at the DSME shipyard on Geoje Island, near the port city of Busan in the southeastern part of South Korea.

“The Dosan Ahn Chang-ho submarine is the Navy’s first mid-class submarine and has been built with a combination of cutting-edge technologies,” the ROKN said in a press release at the time. “This is a national strategic weapons system capable of responding to all threats, and it will help strengthen the Navy’s defense capabilities.”

As I explained last year.

The entire KSS-III class of subs will be produced in three batches. The first batch will include three boats, each fitted with six vertical missile tubes with the first two submarines to be assembled by DSME and the third to be built by South Korean shipbuilder Hyundai Heavy Industries (HHI). The first three boats are expected to be operational by the early 2020s.

The next batch of three submarines, also fitted with a six-tube vertical launch system, is slated to be deployed by 2025, while the last three boats, reportedly boasting a displacement of over 3,500 tons and equipped with 10 vertical launch tubes each, will all be delivered to the ROKN by 2029. Each batch will reportedly see a gradual increase in the number of indigenous components used for the various sub-systems of the boats.

The air-independent propulsion powered KSS-III boats will be the first ROKN SSK to have the capability to vertically launch ballistic or cruise missiles. Notably, the South Korean Ministry of Defense’s (MoD) Agency for Defense Development (ADD) part of the Defense Acquisition Program Administration (DAPA), has partnered up with South Korean defense contractor LIG Nex1 to design and produce a new submarine-launched ballistic missile (SLBM) for the KSS-III SSK class.