Singapore has taken a significant step towards modernising its submarine fleet and enhancing regional maritime security. ThyssenKrupp Marine Systems (TKMS) announced on 7 May 2025 that it has signed a contract with the Defence Science and Technology Agency (DSTA) of Singapore for the construction of two additional Type 218SG submarines for the Republic of Singapore Navy (RSN). This new order brings the total number of Type 218SG submarines, also known as the Invincible class, of the RSN to six. The first two submarines entered service in September 2024.
The Type 218SG design stands out as an improved version of TKMS’s successful Type 214 submarine for export. Some of the special design features in this design, such as the X-shaped rudder section that provides superior maneuverability in shallow coastal waters, are taken from the German Navy’s Type 212 submarine. This hybrid approach gives the Type 218SG an effective operational capability in both open seas and coastal waters.
Technical Specifications of Type 218SG
According to information provided by ESD, the Type 218SG submarines have a compact design with a width of 6,3 meters and a length of 70 meters. With a displacement of approximately 2.000 tons above water and 2.200 tons underwater, these submarines can reach speeds of 10 knots (19 km/h) above water and 15 knots (28 km/h) underwater. One of its most striking features is its fuel cell-powered Air-Independent Propulsion (AIP) system. Thanks to this system, the Type 218SG can operate much quieter than diesel-electric submarines and can stay underwater for long periods. According to estimates, these submarines can survive between 28 and 42 days without needing a snorkel.
Weapon Systems and Special Operations Capabilities
The Type 218SG is equipped with an impressive range of weapons. The submarine has a total of 8 forward-firing torpedo tubes, 533 x 2 mm and 650 x 10 mm. These tubes can launch heavy torpedoes as well as anti-ship missiles and sea mines. The Type 218SG also has a horizontal airlock that allows combat divers and special forces teams to land discreetly. This feature shows that the submarine can play an important role not only in conventional naval warfare missions, but also in special operations.
Statements from TKMS CEO
TKMS CEO Oliver Burkhard expressed his satisfaction with the additional order. “The additional order highlights the generally positive market situation in shipbuilding and gives us the opportunity to further expand our very full order book. We are also proud that Singapore has once again placed its trust in us, as our partnership goes far beyond submarine production. We feel deeply connected to the country and with our products we contribute to the security and defense capabilities of our customer’s country,” Burkhard said. These statements underscore the long-term and strategic partnership between TKMS and Singapore.
Singapore's Strategy to Strengthen Its Submarine Fleet
Singapore’s additional submarine order is an important part of the country’s maritime security strategy. With its strategic location, Singapore aims to have a strong naval force to ensure the security of maritime trade routes and support regional stability. With their advanced technologies and long-term underwater endurance, the Invincible-class submarines will make a significant contribution to Singapore’s submarine fleet and enhance the country’s deterrent at sea. This modernization process, which began with the commissioning of the first two submarines, is expected to accelerate further with the new orders.
