South Korea submarine plan lifts defense supply chain

June 8 (Asia Today) -- South Korea's submarine industry is entering a major transition as the government moves to pursue both advanced diesel-electric submarines and its first nuclear-powered submarine program.

The shift comes as renewed great-power rivalry and aging naval fleets among allied countries have placed underwater defense systems at the center of national security strategy.

Hanwha Ocean and HD Hyundai Heavy Industries are competing for Canada's Patrol Submarine Project, one of the world's largest submarine procurement programs. The project is estimated at nearly 60 trillion won, or about $39 billion, and calls for the phased introduction of 12 diesel-electric hybrid submarines.

Defense and maritime strategy experts said South Korea's KSS-III Jangbogo-III submarine platform has drawn attention for its operational performance. Its advantages include lithium-ion batteries that extend underwater operations and South Korea's shipbuilding infrastructure, which can deliver vessels on schedule and within planned budgets.

Sim Kyu-chan, a senior adviser at Bae, Kim & Lee and a retired Navy admiral, said long-term maintenance, repair and overhaul capabilities are critical because defense partnerships continue for more than 30 years after delivery.

"South Korea is an attractive option for Canada because it has the capacity for technology transfer and local maintenance, repair and overhaul infrastructure," Sim said.

The industry also received a major boost after President Lee Jae Myung formally launched the Jangbogo-N program, South Korea's first nuclear-powered submarine project, during a Future Defense Strategy Committee meeting at the Naval Academy in Jinhae on May 26.

The government is aiming to launch and deploy the submarine in the mid-to-late 2030s. The project is expected to provide long-term momentum for South Korea's submarine industry.

As discussions advance over a small reactor using low-enriched uranium and possible coordination under the South Korea-U.S. nuclear agreement, domestic companies are expected to move beyond diesel-hybrid systems into the more advanced nuclear submarine supply chain.

Nuclear-powered submarines can remain submerged far longer than conventional submarines, giving them strategic value for monitoring and deterring underwater threats. Industry officials said the project could also raise technology standards across related equipment sectors.

Submarines require high technical standards because they must operate under extreme underwater pressure and in sealed environments. A single defective component can endanger the vessel and crew, making military-grade testing and localization essential for suppliers.

South Korea's submarine ecosystem is built around Hanwha Ocean and HD Hyundai Heavy Industries, which handle system integration, final assembly and construction. If the two shipbuilders win major overseas orders, industry officials said the benefits could flow to small and midsize defense parts suppliers.

Key areas include precision navigation and electric propulsion. FIBERPRO supplies fiber-optic gyro-based inertial navigation and measurement systems, which help submarines determine their position without outside signals. Vitzrocell and Samsung SDI are active in special thermal batteries, lithium battery systems and other power-related technologies.

Mechanical, propulsion and hull-control systems are also supported by domestic suppliers. Hanwha Engine and STX Engine produce low-noise and low-vibration diesel engines and generator systems. BMT and Taekwang supply high-pressure fittings and valves used in cooling, fuel and hydraulic systems. HANLA IMS provides shipboard measurement and monitoring systems.

Defense industry officials said these suppliers could strengthen South Korea's position in the global submarine market if the government backs the sector with financing, diplomacy and long-term procurement planning.

A senior executive at a maritime defense company, speaking on condition of anonymity, said submarine projects require patience because the period from contract signing to construction and payment collection can be long.

"Unexpected diplomatic and political variables frequently affect global defense bids," the executive said. "Government policy financing and diplomatic support are needed so small and midsize partner companies are not shaken during the process."

Experts also warned against short-term market overheating, saying South Korea needs a national master plan to turn current momentum into a sustainable defense manufacturing ecosystem.

-- Reported by Asia Today; translated by UPI

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Original Korean report: https://www.asiatoday.co.kr/kn/view.php?key=20260608010002435

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This story was originally published June 8, 2026 at 6:20 PM.