South Korean shipbuilder Hanwha Ocean showcased its OCEAN-40F frigate design at the Defense & Security 2025 exhibition in Bangkok. The 4,000 tons design marks Hanwha’s second proposal for Thailand, following the successful delivery of HTMS Bhumibol Adulyadej which was commissioned in 2019. The new design features weapons and systems from European partners along with enhanced counter-drone capabilities.
The OCEAN-40F represents a leap in capability over its predecessor. At 4,000 tons, the new design is 250 tonnes heavier than the 3,750 tons Bhumibol Adulyadej, providing additional space for enhanced weapons systems, sensors, and growth margin for future upgrades. Hanwha Ocean representatives on the booth explained that the design philosophy rests on three pillars: “Larger, Lethal, and Legendary, representing increased scale and operational presence, multi-domain combat readiness, and a future-proof platform worthy of the Royal Thai Navy’s distinguished heritage.“
Hanwha Ocean has signed memorandums of understanding with France’s Naval Group to serve as combat management system and sensors integrator, and with MBDA for weapons integration. This partnership delivers a strike capability centered on MBDA’s Exocet MM40 Block 3c anti-ship missiles, which offer both over-horizon engagement and coastal attack capabilities. The company also signed an MoU with Cohort Group, including collaboration on sonar systems, torpedo launcher systems, surveillance, targeting and fire-control systems as well as communications management.
The frigate’s air defence is provided by a 16-cell vertical launch system equipped with MBDA’s VL MICA NG surface-to-air missiles, and two SIMBAD RC launchers (forward and aft) add additional close-range air defense capability. The weapons suite is rounded out by a 76mm main gun,and two 30mm remote weapon stations that serve dual purposes in both conventional surface warfare and emerging asymmetric threats.
With the Russo-Ukrainian war and the conflict in the Red Sea, counter-drone capabilities have emerged as a critical requirements for modern naval platforms, and the OCEAN-40F addresses this comprehensively. “The ship will have both hardkill and softkill measures,” a Hanwha Ocean representative explained. “RF jamming and GNSS spoofing capabilities provide softkill options to disrupt drone navigation and control, complemented by hardkill capabilities with the 30mm guns.” The 4D air surveillance radar plays a central role in detecting small, low-flying drones.
Stealth has been a fundamental design consideration from the outset. The frigate features inclined hull surfaces and superstructure to minimize radar cross-section, with simplified shapes for all exposed equipment and an enclosed radar mast to reduce radar reflectivity. Beyond radar stealth, the design incorporates infrared signature suppression through exhaust gas silencers and specialized thermal coatings, a degaussing system for magnetic silence, and an enhanced propeller design to minimize underwater radiated noise.
The OCEAN-40F features a comprehensive sonar suite including hull-mounted sonar, towed array sonar, and notably, an intercept sonar designed to detect combat divers and small unmanned underwater vehicles. This layered underwater detection capability is complemented by torpedoes and acoustic decoys for countermeasures and underwater strike.
The frigate’s integrated survivability philosophy addresses the full spectrum from detection avoidance to post-damage recovery. Beyond low-observable features, the design includes structural reinforcement in critical areas, underwater explosion-proof construction, ballistic protection for vital systems, and comprehensive damage control arrangements. Crew training facilities and advanced firefighting systems ensure the ship can maintain essential functions even after sustaining battle damage.
Hanwha Ocean faces competition from several established players in the Thai frigate program. Hyundai Heavy Industries, Spain’s Navantia, Türkiye’s TAIS consortium, and potentially China’s CSSC are all vying for the contract.
“The Royal Thai Navy hasn’t issued a request for proposal yet, so we’ve made the design flexible to meet the RTN’s upcoming requirements,” the Hanwha Ocean representative noted.
