On Wednesday, April 22, 2026, the investigation into the fire aboard the South Korean Sohn Won-yil-class submarine ROKS Hong Beom-do (SS-079), which occurred on April 9 of this year at HD Hyundai Heavy Industries’ shipyard in Ulsan, was completed. The vessel was deemed to have been completely destroyed from the inside by the fire.
Photo: ROK Navy
ROKS Hong Beom-do (SS-079) was the seventh of nine conventional Sohn Won-yil-class submarines built under the KSS-II/Jangbogo 2 program under license from Germany’s Type 214 design, with air-independent propulsion (AIP). It was 65 m long, 6.3 m wide, had a draft of 6 m, a surfaced displacement of 1,690 tonnes, and a submerged displacement of 1,860 tonnes. It was built by HD Hyundai Heavy Industries and entered service on January 19, 2018. It was named after Korean independence activist Hong Beom-do. Its armament consisted of eight 533 mm torpedo tubes capable of launching Sub-Harpoon cruise missiles.
Before the accident, the submarine had been undergoing a major overhaul since June 2025, which was scheduled to be completed in October of this year. The work covered the hull, equipment, and modernization of combat systems. However, on Thursday, April 9, at 1:58 p.m. local time, a fire was reported inside the aft section of the vessel. At 2:38 p.m., 31 fire units arrived at the scene, with 57 firefighters. The firefighting operation lasted until 3:56 p.m.
At the time the fire broke out, 47 people were aboard the submarine. Most managed to evacuate under their own power. One person, a 60-year-old woman employed by a subcontractor, who was cleaning or performing auxiliary work, was unable to escape and became trapped in the submarine’s narrow spaces. After 33 hours, on the evening of April 10, her body was found in a narrow passageway in the lower part of the submarine, near an escape hatch.
According to the inspection, the fire caused serious damage inside the submarine’s hull: cables and pipes that were part of the onboard installations melted, while the necessary flooding of the vessel with extinguishing agents caused additional damage, especially to sensitive systems such as electronics.
HD Hyundai Heavy Industries suspended work at the shipyard for some time for safety reasons and apologized to the Republic of Korea Navy Command (Daehanminguk Haegun) for the incident. A detailed investigation involving the police, prosecutors, fire service, National Forensic Service, and Ministry of Labor is ongoing. The area around the battery compartment is among the suspected points of ignition, but the exact cause has not yet been publicly confirmed.
According to press reports, the shipyard insured the submarine for the duration of the overhaul for only 50% of its value – that is, 250 billion KRW out of 500 billion KRW. The fire could have very serious financial consequences for the contractor.
See also: