South Korea has officially launched its newest and most advanced submarine to date, the ROKS Jang Yeong-sil (SS-087), marking a significant step in the country’s push for a true Korean-built submarine and a major milestone in its ongoing pursuit of defence self-reliance.
The launch ceremony, held earlier today at Hanwha Ocean’s massive Geoje shipyard in South Gyeongsang Province, drew senior defence officials, naval leadership, and representatives from South Korea’s expanding defence-industrial base.
The Jang Yeong-sil is the first of the KSS-III Batch II line—the next generation of indigenous diesel-electric submarines that stands as the diamond in the crown of Seoul’s naval modernization effort.
Several improvements have been made in the Batch II submarines compared to the Batch I. For the first time ever, a Korean submarine will be equipped with lithium-ion batteries instead of the traditional lead-acid batteries found in most diesel-electric submarines.
Compared to lead-acid, lithium-ion batteries provide significantly higher energy density, allowing longer submerged endurance and faster speeds without increasing the vessel's weight.
They recharge more quickly, enabling shorter snorkel or surface times that reduce detection risk. They also require less maintenance, have a longer operational lifespan, and are safer with modern thermal management systems.
The Batch II will use commercial NCM cells from Samsung SDI, although Hanwha plans for new options to be available by the time the first of the class is delivered. This will allow the Batch II to stay submerged for several weeks longer than her Batch I sisters, reportedly up to six to eight weeks.
They will also feature an improved air-independent propulsion (AIP) system, a new retractable bow thruster, an upgraded sonar suite developed by LIG Nex1, new MTU 4000 U83 engines built under license by STX, and an enhanced combat management system.
Their combat capabilities have also received an upgrade, with the Batch II increasing its vertical launch system (VLS) count from the Batch I’s six cells to ten. The KSS-III is one of the few conventional submarines in the world equipped with a VLS, capable of firing the Hyunmoo IV-IV submarine-launched ballistic missile (SLBM).
The Jang Yeong-sil is the culmination of several years of research and systems development undertaken by Hanwha Ocean and the Defense Acquisition Program Administration (DAPA).
“This launch signals a leap forward in our pursuit of a smart, elite naval force,” said Admiral Kang Dong-gil, Chief of Naval Operations, who presided over the event. “I am confident that the Jang Yeong-sil, constructed with our own technology, will fulfill its mission as a key force in defending our maritime sovereignty.”
The submarine will now undergo outfitting, systems integration, and sea trials before entering Republic of Korea Navy (ROKN) service in 2027. Once commissioned, she will operate alongside the earlier Batch I units Dosan Ahn Chang-ho, Ahn Mu, and Shin Chae-ho.
The Jang Yeong-sil is named after the 15th-century Korean inventor and scientist. When she joins the fleet, she will serve as a central node in the Republic of Korea Navy’s drive toward a blue-water capable force. She will also play a key role in the Republic of Korea’s Third Axis, the “Korea Massive Punishment and Retaliation” (KMPR) strategy.
While there was a push for the launch ceremony to take place during Prime Minister Mark Carney’s visit, scheduling conflicts prevented that from happening. They did try though.
Instead, he will be given a tour of the Jang Yeong-sil when he visits South Korea for APEC 2025 next week. He will be joined by other officials that TNSR has yet to confirm.
The Geoje launch underscores Hanwha Ocean’s growing prominence as South Korea’s premier naval shipbuilder. Formerly known as Daewoo Shipbuilding & Marine Engineering, the yard has become the focal point of national submarine development, transforming from a licensed builder of foreign designs into the core of South Korea’s submarine revitalization.
For Canada, the launch of the Jang Yeong-sil represents a new firsthand opportunity for officials to see what they might be getting. Team One Korea has offered Canada the KSS-III Batch II as its bid for the Canadian Patrol Submarine Project.
Having the submarine in the water, able to be seen and toured, will go a long way toward demonstrating the capabilities of the Batch II. It gives Hanwha the unique ability to actually show their proposal to officials.
It’s an advantage that shouldn’t be underestimated, especially with the Jang Yeong-sil being delivered on time and under budget. Officials like to see things. They like demonstrations, to have the chance to experience everything in person and ask questions.
Getting this submarine launched at such a critical time in the competition, especially right before the Prime Minister’s visit, gives Hanwha a one-time opportunity to sway him with what is, essentially, the submarine that Canada would receive if Team One Korea is selected.
For the Eurocentric Prime Minister, who is reportedly already leaning toward the Type 212CD, this is the one chance Hanwha might have to convince him of their value as a strategic partner.
Being able to get him inside the submarine itself is going to be a major part of that—it might even mark a turning point in his opinion.
I guess we’ll see next week.
Figures Carney is leaning toward the 212CD he's not interested in what the Navy actually needs nor how fast they need it. He seems to only care about his European deals and the political implications that come with it. Just another Liberal fail on procurement. On the bright side for him atleast he won't have to spend the money for them nearly as quickly, as the Victoria's would likely all be retired long before Canada receives a second submarine and after that who knows, especially if Poland ops for the 212CD. Will likely be several decades with that choice before Canada sees more than one submarine total operational at a time.
This is the first I've heard that Carney might be leaning towards the 212CD. Sure hope the Koreans make a good impression on him....fingers crossed