Bangladesh to procure 6 improved KSS-I submarines from South Korea to protect its maritime territory.

According to BDMilitary on May 21, 2025, the Bangladesh Navy is engaged in advanced negotiations with South Korea for the acquisition of six Improved Jang Bogo-class submarines under a defense procurement program valued at approximately $2 billion. The submarines are based on the German Type 209/1400 diesel-electric submarine design and are manufactured by Daewoo Shipbuilding & Marine Engineering (DSME). These units are planned to be stationed at BNS Pekua, a newly completed submarine base near Cox’s Bazar constructed by China’s Poly Technologies at a cost of $1.29 billion.
Follow Army Recognition on Google News at this link

The acquisition of six Improved Jang Bogo-class submarines is part of a broader naval strategy to enhance Bangladesh’s submarine fleet through capabilities that support both offensive and defensive underwater operations in the Bay of Bengal and surrounding maritime areas. (Picture source: US DoD)

The BNS Pekua facility, now functioning as the headquarters of the Submarine Fleet Command, was purpose-built to accommodate underwater platforms and includes dry dock facilities for maintenance, workshops for propulsion systems and battery support, secure electronic infrastructure, and space for logistical operations. The base is protected with coastal surveillance radars and perimeter security systems and is designed to ensure rapid repair and operational readiness for the submarine fleet. Its strategic location near Cox’s Bazar allows the Bangladesh Navy to deploy vessels swiftly to eastern maritime zones, with direct access to sea lanes near Chattogram and the Andaman Sea. From this location, Bangladesh will be positioned to monitor key maritime routes and respond more efficiently to regional developments in the northern Bay of Bengal, including possible incursions or encroachments.

The procurement discussions with South Korea include clauses on lifecycle support, local assembly of key subsystems, and potential technology transfer for long-term sustainability. Under joint-venture or offset arrangements, Bangladesh has the option to locally produce components and munitions such as the Baek Sang Eo (White Shark) torpedoes. These negotiations also address future collaboration in maintenance, mid-life upgrades, and obsolescence management. Training of submarine crews, engineers, and technicians is expected to begin in South Korea, with in-country capacity development supported by South Korean contractors. The submarines will be equipped with South Korean-developed weapons, including the White Shark torpedo and the Haeseong-3 (C-Star) sub-launched cruise missile, along with provisions for Tiger Shark torpedoes as a future option and Smart Underwater Mines. This suite is intended to provide compatibility with South Korea’s K-CMS Combat Management System, facilitating target tracking, classification, and engagement through integrated electronic countermeasures.

The rationale for the acquisition, which is being considered alongside other Korean naval platforms, is tied to Bangladesh’s maritime requirements, including surveillance and deterrence in its Exclusive Economic Zone (EEZ), protection of offshore energy resources, and monitoring of fishing grounds. The strategic goal is to establish a credible underwater capability in response to growing submarine activity from neighboring countries, specifically India and Myanmar. The deployment of six submarines will permit staggered patrols and intelligence-gathering rotations, ensuring a persistent presence even during periods of crew rest or vessel maintenance. The Improved Jang Bogo-class submarines offer a submerged speed of 21.5 knots, surfaced speed of 11 knots, an endurance of up to 50 days, and a range of about 11,000 kilometers while snorkeling at 10 knots. With a crew capacity of 33 to 40 personnel and six 533mm torpedo tubes, the submarines are intended to deliver munitions for anti-ship, land-attack, and area-denial operations within Bangladesh’s maritime zones. The introduction of this capability is expected to strengthen Bangladesh’s deterrence posture, provide a platform for participation in multilateral naval exercises and humanitarian operations, and support regional stability through enhanced maritime situational awareness and security cooperation.

The Jang Bogo-class submarine, designated as KSS-I, is based on the German Type 209/1200 diesel-electric submarine design and constitutes the South Korean Navy’s first domestically constructed submarine class. Its development began with a 1987 order for three boats, following the approval of the Korean Submarine Program (KSS), with the first submarine, Jang Bogo (SS-061), built in Kiel, Germany, and commissioned in 1993. The second and third submarines, Icheon (SS-062) and Choi Mu-seon (SS-063), were assembled in South Korea using German-supplied components. Two additional batches were ordered in 1989 and 1994, bringing the total to nine submarines, all delivered by 2001. Organized under the ROK Navy’s Submarine Command, they were operated in six three-ship squadrons on a rotation basis for patrol, standby, and maintenance duties. The Jang Bogo-class laid the foundation for South Korea’s indigenous submarine construction capabilities and was later used as the basis for the Nagapasa-class submarines exported to Indonesia. South Korea remains the only country outside Germany to independently offer Type 209-based submarines for export.

Extensive modernization efforts began in the early 2000s to extend the service life and improve the combat capabilities of the Jang Bogo class. The upgrades included hull extensions to increase displacement from 1,200 to 1,400 tons, installation of the domestic ISUS-83 combat system, integration of White Shark heavyweight torpedoes, and addition of UGM-84D Harpoon missile launch capabilities from four of the eight 533 mm torpedo tubes. Some vessels were also equipped with TB-1K towed array sonar systems, improving detection and tracking of underwater targets. LIG Nex1 developed and produced the Torpedo Acoustic Counter Measures (TACM), and by 2000, these had been integrated into several units. Further upgrades included improved periscopes, sonar systems, and the potential integration of submarine-launched Hae Sung anti-ship cruise missiles. The enhancements reportedly improved low-frequency detection range by a factor of three, the number of simultaneously analyzable targets by four, and target tracking by two to four times compared to the original Type 209 design. There are ongoing development efforts to integrate lithium-ion battery power stacks to increase submerged endurance and power density. South Korea has not publicly disclosed whether air-independent propulsion (AIP) retrofits will be applied to this class.

The Jang Bogo-class has a surfaced displacement of approximately 1,200 tons and a submerged displacement of up to 1,400 tons, with a length of 56 meters (extended to 61.3 meters in export variants), a beam of 6.3 meters, and a draft of 5.5 meters. It is powered by four MTU Type 8V396 SE diesel engines and a Siemens electric motor driving a single shaft, generating 5,000 shp. The submarine’s maximum submerged speed is approximately 21.5 knots, while its surfaced speed is 11 knots. It has an endurance of 50 days and a range of 11,000 nautical miles at 10 knots surfaced, 8,000 nautical miles snorkeling, and 400 nautical miles submerged at 4 knots. Operational depth is rated at 500 meters. The standard complement is 33 personnel, including six officers. Each submarine is armed with eight 533 mm torpedo tubes that can launch 14 torpedoes, typically a combination of German SUT Mod 2 and Korean K-731 White Shark torpedoes, as well as up to 28 naval mines. The platform's acoustic signature has been reported between 100 and 110 decibels, with performance during multinational exercises such as RIMPAC and Pacific Reach showing the ability to operate undetected in proximity to high-value naval assets. Despite the training context limitations, exercises demonstrated the ability of these submarines to evade detection and simulate engagements with major surface combatants.

The Jang Bogo-class submarines have participated in several RIMPAC and bilateral exercises, simulating attacks against aircraft carriers, cruisers, and destroyers. For instance, Lee Jong-mu (SS-066) reportedly achieved 13 simulated kills totaling 150,000 tons during RIMPAC 1998, while Park Wi (SS-065) simulated the sinking of 11 ships at RIMPAC 2000 and completed a 137-day round-trip voyage to Pearl Harbor, a record for ROK submarines. Na Dae-yong (SS-069) launched the first Harpoon missile in exercise conditions in 2002 and simulated hits on ten ships totaling 100,000 tons. Jang Bogo (SS-061) reportedly achieved over 40 simulated torpedo hits in a single exercise in 2004, undetected throughout. Icheon (SS-062) destroyed a decommissioned cruiser in a training scenario using a German-made SUT torpedo in 1999. While these exercises are constrained by operational boundaries and scripted rules of engagement, they contributed to the development of South Korea’s submarine doctrine and crew training. The Jang Bogo class played a key role in exposing U.S. and allied forces to the threat posed by conventional submarines during peacetime drills and reportedly contributed to the U.S. decision to lease Sweden’s Gotland-class submarine for further anti-submarine warfare training.