The Republic of Singapore Navy (RSN) has officially welcomed its second Type 218SG submarine, the RSS Invincible, at Changi Naval Base. The submarine arrived on Tuesday, August 27th, aboard the heavy transport vessel MV Rolldock Star, which docked at approximately 11:40 AM local time. RSS Invincible, the lead submarine of the Invincible-class, was launched on February 18, 2019, in Kiel, Germany. With its arrival, the RSN will begin a series of trials and crew training exercises to ensure the submarine’s operational readiness. Two more submarines of this class, the RSS Illustrious and RSS Inimitable, are expected to be delivered by 2025. The Type 218SG submarine is a collaborative design effort between Singapore’s Defence Science and Technology Agency (DSTA), ThyssenKrupp Marine Systems (TKMS), and the RSN. It is specifically tailored to meet the RSN’s operational needs, including maritime operations in littoral waters, securing sea lines of communication, intelligence-gathering, and supporting special operations. The Type 218SG’s design draws elements from the Type 214 and Type 212 submarines, and incorporates concepts from the Type 216 submarine.
In November 2013, Singapore’s Ministry of Defense (MINDEF) selected the Type 218SG design from TKMS. The initial contract, valued at USD 1.36 billion, included two submarines along with a comprehensive training and logistics package. This marked the RSN’s first order for custom-built submarines, as previous acquisitions involved second-hand vessels. By May 2017, an additional order for two more Type 218SG submarines was placed, raising the total to four, with deliveries scheduled between 2024 and 2025. Construction of the first Type 218SG began in 2014 at TKMS’s Kiel shipyard. The lead boat, RSS Invincible, was launched on February 18, 2019, with key defense officials in attendance. However, its delivery was delayed to 2022 due to COVID-19 restrictions. The construction of subsequent submarines began in January 2018. By December 2022, the second and third submarines, RSS Impeccable and RSS Illustrious, were launched, with the final boat, RSS Inimitable, launched in April 2024. The overall cost for these acquisitions is estimated at USD 1.8 billion. In December 2021, it was reported by German media that an additional submarine might be under negotiation, although this has not been confirmed by either RSN or TKMS.
The Type 218SG is 70 meters in length with a beam of 6.3 meters, and has a displacement of around 2,000 tons when surfaced and 2,200 tons when submerged. The submarine is capable of reaching speeds of 10 knots on the surface and 15 knots underwater. The Type 218SG submarine, designed for the Republic of Singapore Navy, incorporates several advanced features to enhance its operational capabilities. It boasts an X-shaped rudder configuration for superior maneuverability in shallow littoral waters, a fuel-cell-powered air-independent propulsion (AIP) module for extended underwater endurance of up to 28-42 days, and a Horizontal Multi-Purpose Airlock (HMPL) for launching torpedoes, special operations forces, divers, and submarine-launched cruise missiles. The submarine is designed with extensive ergonomic considerations for crew comfort, such as air conditioning, enlarged living quarters, personal entertainment systems, and additional facilities, while also employing automation technologies that reduce crew size and improve operational efficiency. The submarine’s payload capacity is enhanced, providing greater firepower than its predecessors, and it is built using materials suited for Singapore’s tropical climate and saline waters.
Current details about the Type 218SG’s armament are scant and almost non-existent; however, it is understood that the submarine features eight 533-millimetre (21.0 in) and two 650-millimetre (26 in) forward-firing torpedo tubes— (same configuration with Israel’s Dolphin-II submarines) which may be used for firing heavyweight torpedoes, anti-ship missiles and for laying naval mines, as well as a dedicated horizontal air-lock, to disembark naval special forces teams. The Type 218SG is reported to have a greater ordnance payload (and essentially greater firepower) than the RSN’s previous submarines, owing to its much larger size. Not much about the Type 218SG’s sensors and automation have ever been reported by Singapore; however, it is understood the submarines are equipped with a “Combat Management System” (CMS) jointly developed by German-based Atlas Elektronik and Singapore-based ST Electronics, along with data analytics and decision support engines developed by the DSTA.
