Projects

KSS-III (Jangbogo-III) Class Attack Submarines

KSS-III (Jangbogo-III) class, also known as Dosan Ahn Chang-ho class, is a series of next-generation diesel-electric attack submarines being built to strengthen the naval defence capability of the Republic of Korea Navy (RoKN).

Project Type

Attack submarine

Builders

DSME and Hyundai Heavy Industries (HHI)

Operator

Republic of Korea Navy (RoKN)

Crew

50

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KSS-III (Jangbogo-III) class, also known as Dosan Ahn Chang-ho class, is a series of next-generation diesel-electric attack submarines being built to strengthen the naval defence capability of the Republic of Korea Navy (RoKN).

The KSS-III project involves the development of nine attack submarines being built in three batches as part of South Korea’s indigenous submarine production programme.

The first and second hulls of Batch-I are being built by Daewoo Shipbuilding & Marine Engineering (DSME) and the third is being constructed by Hyundai Heavy Industries (HHI).

The Batch-II will include three submarines with some design changes to Batch-I hulls. The remaining three submarines will form part of Batch-III and will feature even more advanced technologies.

KSS-III class development details

The Agency for Defence Development (ADD) of South Korea issued a total of five requests for proposals (RFPs) for the KSS-III submarine project in February 2009.

The Ministry of Defence of South Korea awarded a contract to DSME in December 2012 for the construction of two KSS-III Batch-I submarines. The contract for the third submarine of Batch-I was awarded to HHI in November 2016.

Steel-cutting ceremony of the lead submarine of the KSS-III Batch I, Dosan Ahn Chang-ho, was held at DSME’s Okpo shipyard in November 2014 and the submarine was launched in September 2018. The sea trials of the submarine are underway, while delivery is scheduled for the end of 2020.

The keel for the second submarine, Son Byong-hi, was laid down in July 2016. It will be delivered by the end of 2022.

Construction on the third and final submarine of Batch I began at HHI’s shipyard in Ulsan in June 2017. The submarine is named Yi Dongnyeong.

The construction of KSS-III Batch-II submarines was approved in March 2019. South Korea’s Defense Acquisition Program Administration (DAPA) selected DSME for Batch-II basic design in May 2016.

The last and final submarine of the project is expected to be delivered by 2029.

Design and features of Jangbogo-III Batch-I submarines

KSS-III Batch-I submarines will be 83.3m-long, 9.6m-wide and will have a draught of 7.62m. With a gross tonnage of approximately 3,000t, the submarines will be capable of accommodating a crew of 50.

The submersibles will be operated and controlled using steering and diving consoles developed by ECA Group. A numerical autopilot in the consoles will allow for operation and control of the submarine in automatic, manual and mixed modes.

The submarines will carry continuous active sonar (CAS) and flank array sonar (FAS) for detection, classification and localisation of targets.

The KSS-III-class will also be integrated with a combat management system developed by Hanwha for the armament assignment, target detection and tracking, and engagement in linkage with the sensors.

Armament of Batch-I submarines

KSS-III Batch-I submarines will be fitted with six vertical launch system (VLS) tubes and eight 533mm torpedo tubes. The boats will also be capable of carrying cruise and ballistic missiles.

The first and second submarines in Batch-I will be equipped with Babcock’s weapons handling and launch system (WHLS).

The WHLS incorporates air turbine pump (ATP)-driven positive discharge and programmable firing valve launch (PFV) system. It offers compatibility with missiles, torpedoes and mines produced by suppliers in Spain, South Korea and the UK.

Sensors and navigation systems of KSS-III Batch-I submarines

The Batch-I submarines will be equipped with Safran Electronics & Defense’s new generation electro-optical surveillance masts, which will feature high image resolution and processing capabilities.

The submarines will be integrated with signal intelligence (SIGINT) system and an infrared (IR) system for discreet communications. A Link 11 tactical data link will be installed to facilitate secure data transfer.

The navigation aids aboard the submarines will include inertial navigation system (INS) and global positioning system (GPS).

The submarine will also feature marine radar, PEGASO electronic support system (ESM), active sonar, and towed array sonar for detection of targets.

Performance of KSS-III Batch-I submarines

Powered by a diesel-electric, fuel-cell air-independent propulsion system, the KSS-III Batch-I submarines will be capable of conducting long-distance underwater operations for up to 20 days.

The submarines can attain a maximum operating speed of approximately 20kt and a cruising range of 10,000nm.

Contractors

Sagem (now Safran Electronics & Defense) was awarded a contract by DSME to supply its new generation electro-optical surveillance masts for integration onto the first two Batch-I submarines, in October 2014.

Babcock was awarded a contract by DSME in September 2017 to design and produce WHLS for the first and second Batch-I submarines through 2024.

DSME placed a contract with ECA in June 2020 for the supply of the steering and diving consoles for the first KSS-III Batch-II submarine. Delivery of the equipment is scheduled for 2023, while the operational tests will be completed by 2027.

Hanwha is supplying combat management system for both Batch-I and Batch-II submarines, while LIG Nex1 is providing flank array sonars.

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