Poland’s new KSS-III subs threaten Russia’s Baltic dominance.
Announced in early April 2025, the proposal includes not only the delivery of three advanced diesel-electric submarines but also a comprehensive maintenance, repair, and overhaul package, investments in Polish shipyard infrastructure, and a leased vessel for crew training.
The first submarine could be delivered within six years of a signed contract, with all three in service within eight and a half years, according to Hanwha representatives. This development, reported by Janes on April 21, 2025, signals Poland’s intent to modernize its aging fleet and bolster its strategic position in a region marked by growing tensions with Russia.
Why is a South Korean shipbuilder vying for a European naval contract, and what makes the KSS-III a game-changer for Poland’s maritime ambitions?
The KSS-III Batch 2, also known as the Dosan Ahn Changho-class, represents the pinnacle of South Korea’s submarine technology. Designed and built by Hanwha Ocean and HD Hyundai Heavy Industries, the submarine is a cornerstone of the Republic of Korea Navy’s modernization efforts.
With a surfaced displacement of approximately 3,600 tons and a submerged displacement of around 4,000 tons, the KSS-III measures 89.3 meters in length and 9.6 meters in beam, making it larger than many submarines operating in the Baltic but agile enough for the region’s shallow waters.
Its propulsion system is a standout feature, combining a diesel-electric setup with an air-independent propulsion [AIP] system powered by fuel cells developed by Bumhan Industries. This allows the submarine to remain submerged for over three weeks without surfacing, a critical advantage in the Baltic Sea, where depths average just 50 meters and enemy anti-submarine warfare assets, such as Russian patrol aircraft, are ever-present.
The AIP system, paired with lithium-ion batteries from Samsung SDI, triples the submerged endurance of its predecessor, the KSS-III Batch 1, and reduces propulsion noise, enhancing stealth.
The submarine’s armament further distinguishes it as a formidable platform. It is equipped with six 533mm torpedo tubes, capable of launching heavy torpedoes like the South Korean K761 Tiger Shark or Western equivalents, as well as anti-ship missiles such as the U.S.-made Harpoon or South Korea’s Haeseong.
The KSS-III Batch 2 also features ten vertical launch system [VLS] cells, a rarity for non-nuclear submarines, which can deploy the Hyunmoo-IV-4 submarine-launched ballistic missile or the Chonryong cruise missile. These weapons enable strikes against land and sea targets from hundreds of miles away, giving Poland a strategic reach unprecedented in its naval history.
The submarine’s combat management system, developed by Hanwha Systems, integrates a horseshoe-shaped sonar array from LIG Nex1, offering superior detection in the Baltic’s challenging acoustic environment, where salinity gradients and shallow depths complicate underwater sensing.
Additional sensors include a Thales mine-detection sonar, an Indra radar electronic support measures system, and a Safran Series 30 optoelectronic mast, ensuring comprehensive situational awareness. The high degree of automation reduces the crew requirement to 33, though the vessel can accommodate up to 50 personnel, including special forces for covert operations.
Poland’s current naval capabilities are modest by comparison. The Polish Navy operates a single Soviet-era Kilo-class submarine, ORP Orzeł, commissioned in 1986. With a displacement of 2,450 tons submerged and a length of 72.6 meters, the Kilo-class relies on conventional diesel-electric propulsion, requiring frequent surfacing to recharge batteries.
Its armament includes six 533mm torpedo tubes for torpedoes and anti-ship missiles, but it lacks the VLS capability and AIP system of the KSS-III. The Kilo’s dated sensors and higher noise levels make it vulnerable to modern anti-submarine warfare systems, particularly those of Russia’s Baltic Fleet.
Poland decommissioned its four Norwegian Kobben-class submarines between 2017 and 2021, leaving ORP Orzeł as its sole underwater asset. The Orka program, initiated in 2014 and restructured in 2023, aims to acquire three to four new submarines to replace this aging fleet, with a focus on stealth, cruise missile capability, and interoperability with NATO forces.
The KSS-III’s technical advantages translate into significant strategic benefits for Poland. The AIP system and lithium-ion batteries enable prolonged, stealthy patrols, allowing Polish submarines to monitor Russian naval movements in the Baltic without detection.
The VLS cells provide a deterrent capability, enabling strikes against Russian military infrastructure, such as the heavily fortified Kaliningrad enclave, or naval assets from a safe distance. This marks a shift for Poland from a primarily defensive naval posture to one capable of power projection.
The submarine’s versatility supports multiple missions, including anti-submarine warfare, anti-surface warfare, intelligence gathering, and mine-laying, addressing the Polish Navy’s need for a multi-role platform given its limited fleet size.
The Baltic Sea’s confined and shallow waters demand submarines that can operate covertly and evade detection, and the KSS-III’s acoustic anechoic coating, elastic mounts, and low-noise propulsion make it exceptionally difficult to track, even compared to Russia’s newer Kilo-class variants like the Project 636.3 Varshavyanka.
Hanwha Ocean’s offer extends beyond the submarines themselves, addressing Poland’s operational and industrial needs. The company proposes leasing a decommissioned Jang Bogo-class [KSS-I] submarine, a 1,200-ton vessel based on the German Type 209 design, to serve as a training platform.
Scheduled for decommissioning from the South Korean Navy in 2027, the Jang Bogo would be refitted with command systems compatible with the KSS-III, allowing Polish crews to gain experience before the new submarines arrive.
This interim solution, to be formalized through a government-to-government agreement, mitigates the risk of delays in achieving operational readiness, a common challenge when transitioning to advanced platforms.
Hanwha also commits to establishing a maintenance, repair, and overhaul center in Poland, supported by technology transfers to local companies. This center would ensure timely spare parts delivery, manage equipment obsolescence, and enable Poland to maintain its submarines independently, reducing reliance on foreign support.
Investments in Polish shipyards, potentially involving firms like WB Electronics, aim to create jobs and position Poland as a regional hub for submarine maintenance, echoing South Korea’s successful industrial partnerships in Poland’s K2 Black Panther tank and K9 Thunder howitzer programs.
The KSS-III faces competition from European contenders, notably Germany’s Type 212CD and France’s Scorpène. The Type 212CD, developed by Thyssenkrupp Marine Systems, is a 2,500-ton submarine optimized for the Baltic’s shallow waters.
It features an AIP system using fuel cells and a stealthy design with a non-magnetic steel hull, making it nearly undetectable by magnetic sensors. Its armament includes six 533mm torpedo tubes for torpedoes and mines, with the option for anti-ship missiles like the IDAS system to engage helicopters. However, it lacks VLS cells, limiting its strategic strike capability compared to the KSS-III.
The Scorpène, offered by Naval Group, has a displacement of 1,800 to 2,000 tons and an AIP option using ethanol-based fuel cells. It carries up to 18 weapons, including torpedoes, anti-ship missiles, and mines, but also lacks VLS. Both European submarines are proven designs, with the Type 212 in service with Germany and Norway and the Scorpène exported to Chile, Malaysia, and India.
Yet, Hanwha’s promise of faster delivery—six years for the first KSS-III versus potentially longer timelines for European builders—gives it an edge, especially as Poland seeks to counter Russia’s growing assertiveness following the invasion of Ukraine.
The Baltic Sea is a geopolitical flashpoint, with Russia maintaining a robust naval presence through its Baltic Fleet, based in Kaliningrad and Kronstadt. The fleet operates several Kilo-class submarines, including the quieter Project 636.3 Varshavyanka, which carries torpedoes, anti-ship missiles, and Kalibr cruise missiles.
Russia’s newer Yasen-class nuclear submarines, occasionally deployed to the Baltic, boast advanced sensors and long-range missiles but are less suited to the region’s shallow waters due to their 13,800-ton displacement. The KSS-III’s stealth and firepower make it a credible counter to these threats, particularly in denying Russia control over key maritime chokepoints like the Danish Straits.
Sweden’s A26 Blekinge-class submarines, with AIP and stealth features, already enhance NATO’s underwater capabilities in the Baltic, and Poland’s adoption of the KSS-III would further tilt the balance, creating a networked submarine force alongside German and Norwegian assets.
Historically, Poland’s naval ambitions have been constrained by its focus on land-based defense, a legacy of its position between Germany and Russia. The Polish Navy’s submarine force peaked in the Cold War with five Kilo-class and several smaller vessels, but budget cuts and the obsolescence of Soviet-era equipment reduced it to a single operational submarine by the 2010s.
The Orka program reflects Poland’s post-2014 shift toward rapid military modernization, spurred by Russia’s annexation of Crimea and the ongoing war in Ukraine. Poland has invested heavily in NATO-compatible systems, including U.S.-made HIMARS rocket systems, Patriot air defenses, and South Korean K2 tanks and FA-50 aircraft.
The KSS-III offer builds on this partnership, leveraging South Korea’s reputation for delivering advanced weaponry on time and within budget, as demonstrated by the K9 howitzer program, which saw Poland receive 48 units by 2023.
South Korea’s emergence as a global defense exporter adds another layer to the story. Once reliant on foreign technology, South Korea has developed indigenous capabilities through programs like the KSS-III, which achieves an 80% localization rate with domestically produced systems.
Hanwha Ocean’s success in securing all three KSS-III Batch 2 contracts for the South Korean Navy, with the first vessel set to launch in 2025, underscores its expertise. The company’s outreach to Poland, Canada, and Saudi Arabia reflects a broader strategy to challenge European and U.S. dominance in the arms market.
At the MSPO 2024 exhibition in Kielce, Hanwha signed a memorandum of understanding with Poland’s WB Group to localize MRO services, a move praised by Polish officials, including President Andrzej Duda, who toured Hanwha’s pavilion. This industrial collaboration could transform Poland’s shipbuilding sector, which has struggled to compete with Western European yards since the decline of its Soviet-era industry.
Despite its strengths, the KSS-III proposal is not without challenges. Some Polish submariners have expressed concerns that the submarine’s 3,600-ton displacement is too large for the Baltic’s confined waters, favoring smaller designs like the Type 212CD. Integrating Western systems, such as the Naval Strike Missile, would require cooperation with European manufacturers, potentially complicating exports due to intellectual property restrictions.
The high cost of the Orka program, estimated at over $2.5 billion, may strain Poland’s defense budget, already stretched by commitments to tanks, aircraft, and frigates. Moreover, while Hanwha’s MRO center promises long-term benefits, Poland’s shipyards lack experience with advanced submarine technologies, raising questions about their ability to absorb South Korean know-how quickly.
These hurdles, though not insurmountable, highlight the risks of adopting a non-European platform in a region dominated by German and French suppliers.
From a broader perspective, Hanwha Ocean’s offer is a bold play in a shifting global defense landscape. The KSS-III Batch 2 is not just a submarine; it’s a symbol of South Korea’s technological ascent and Poland’s determination to assert itself as a NATO powerhouse.
For the United States, the deal reinforces the strategic alignment of two key allies, both of whom rely on American weapons systems and share concerns about revisionist powers like Russia and China. The KSS-III’s ability to project power and deter aggression aligns with NATO’s goals in the Baltic, where U.S. naval forces, including Virginia-class submarines, occasionally operate.
Yet, the choice of a South Korean submarine over European alternatives could strain relations with Germany and France, whose shipbuilders have long viewed Poland as a key market. As Poland weighs its options, the decision will reverberate beyond the Baltic, signaling whether non-traditional suppliers can reshape the alliances and technologies that define modern warfare.
Will the KSS-III propel Poland to the forefront of underwater warfare, or will the complexities of integration and cost temper its ambitions? Only time will tell.
Bulgarian military