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18 Aug 2022

ROKS Dosan Ahn Changho Deploys For The First Time

ROKS Dosan Ahn Changho Deploys For The First Time
Photo : ROKN
Originally posted on Naval News

On August 16th, the Republic of Korea Navy (ROKN) confirmed that its first ship-in-class KSS III submarine, ROKS Dosan Ahn Changho, has been operationally deployed for the first time. The feat is the culmination of three years of testing and trials following the submarine’s launch in 2018.

South Korea's first KSS III submarine set sails for its maiden operational deployment

ROKS Dosan Ahn Changho, which was commissioned in August 2021, has already made headlines multiple times for conducting submarine-launched ballistic missiles (SLBMs) tests. Many see the deployment of the vessel as a major milestone, marking the first time the country’s SLBMs will be at sea in an operationally-ready capacity.

“The ability to deploy SLBM-armed submarines during times of conflict is a warning to enemies and provides deterrence…This effect will not be as great as that of American ballistic missile submarines armed with nuclear warheads. However the fact that a ballistic missile submarine will be operating in near waters is still very symbolic.” - Commander Yoo Ji-hoon, Resercher at Korea Institute for Defense Analyses


They also point out that the ROKS Dosan Ahn Changho sets the ROKN apart from the Korean People’s Navy, North Korea’s maritime force. This is because the Sinpo-class submarine, North Korea’s ballistic missile submarine, is not mission ready and is thought to be capable of carrying only three SLBMs at most.

Cutaway of North Korean Navy Romeo Mod Class submarine

The Romeo-Mod submarine will carry three ballistic missiles in the sail, which is an unusual configuration today.


“North Korea’s Sinpo-class submarines use the unconventional method of carrying SLBMs in the bridge…The ROKS Dosan Ahn Changho, on the other hand, uses the Vertical Launch System, making it at least five years more advanced than its North Korean counterpart.” - Rear Admiral Park Jongseung, Director of the Agency for Defense Development


The ROKS Dosan Ahn Changho, on the other hand, can carry up to six SLBMs based on the Hyunmoo-2 ballistic missile. Before the acquisition of the vessel, the Navy relied on the KSS II Sohn Won-yil-class submarines, modified German Type 214s, for at sea deterrence. These ships carry the Hyunmoo-3 cruise missile which have the ability to fly close to the water to minimize detection, but are slow and have limited warhead capacity.

The SLBMs carried on the ROKS Dosan Ahn Changho are significantly faster than cruise missiles and have far greater destructive capacity due to their larger payloads. Unlike cruise missiles, however, they are relatively easy to detect due to their arched flight trajectory. The ROKN hopes that operating both cruise missiles and ballistic missiles from submarines will give it greater operational flexibility.

The new submarine also uses air-independent propulsion (AIP), allowing it to stay submerged for extended periods of time.

About KSS-III Dosan Ahn Changho-class SubmarinesKSS-III Dosan Ahn Changho-class submarine

3,000 tons KSS III submarine ‘Dosan Ahn Chang-ho’ during its seat trials. ROK Navy picture.

The Dosan Ahn Changho-class is named after a prominent independence fighter against Japan’s occupation of the country in the early 20th century. The preliminary design phase for the KSS III program began in 2004. Hyundai Heavy Industries (HHI) and Daewoo Shipbuilding and Maritime Engineering (DSME) were jointly responsible for the design, with local companies LIG Nex1, Hanwha, and STX Engine also being involved in the project. Moreover, British companies BMT and Babcock provided technical assistance.

The Batch I submarine has a crew of 50, length of 83.5 m, width of 9.6 m, and draft of 7.7 m. With a standard displacement of 3,358 tons surfaced and up to 3,800 tons submerged, its maximum submerged speed is 20 knots. The vessel also has a range of 10,000 nautical miles at cruising speed.

In addition to the aforementioned 6 VLS cells, the KSS-III Batch 1 submarines are also fitted with eight 533-mm torpedo tubes. Babcock will provide the weapon handling system, while Spain’s Indra Sistemas will be responsible for supplying the PEGASO electronic defense system. French companies are also involved in the project, with ECA Group producing the steering consoles and Safran the optronic masts. LIG Nex1 and Hanwha will provide flank array sonars and the combat management system, respectively.

Construction on ROKS Dosan Ahn Changho started at DSME’s Okpo shipyard in November 2014, with the launch taking place on September 14th, 2018. The second submarine, ROKS Ahn Moo, was launched by DSME on November 10th, 2020. HHI started construction of ROKS Yi Dongnyeong, the third boat and final vessel of Batch I, in June 2017 at its Ulsan shipyard. It was launched in September 2021.

KSS-III Batch II was approved by the government in March 2019. The Batch II vessels are expected to have a longer hull, bringing the displacement up to around 4,000 tons, and carry an additional four more VLS cells for a total of ten. Moreover, it is expected to use more domestically produced components including lithium ion batteries and high-temperature superconductor motor technology for the integrated full electric propulsion system.

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