Singapore Submarine Capabilities

The Republic of Singapore Navy (RSN) operates a technologically advanced naval force of two Challenger-class (Sjöormen-class) submarines and two Archer-class submarines (Västergotland-class).^{1 2}

Total Submarines in Fleet: 4

• Ballistic Missile Submarines (SSBNs): 0
• Nuclear-Powered attack submarines (SSNs): 0
• Diesel-electric attack submarines (SSKs): 4
• Air-independent propulsion (AIP) enabled: 2/4

Submarines

Between 1995 and 1997, the RSN acquired four second-hand Sjöormen-class submarines from Sweden: the HMS Sjöbjörnen, HMS Sjölejonet, HMS Sjöormen, and HMS Sjöhunden. In the early 2000s, RNS re-commissioned these vessels respectively as the RSS Challenger, RSS Conqueror, RSS Centurion, and RSS Chieftain.³ In November 2005, the RSN signed a contract with Sweden’s Kockums Naval Solutions to purchase two retired Västergotland-class submarines: HMS Hälsingland and HMS Västergötland. The RSN re-commissioned these vessels in 2011 and 2013 as the RSS Archer and RSS Swordsman.⁴

In December 2013, Singapore purchased two Type 218SG submarines from the German group Thyssen-Krupp for 1.36 billion USD. The long-range vessels will be equipped with the Air Independent Propulsion system (AIP). ⁵ In February 2019, the first vessel, the RSS Invincible, was launched in Kiel. It will be delivered to Singapore in 2022.⁶ In 2017, Singapore’s Ministry of Defence announced a decision to procure two additional Type 218SG submarines; the new boats were laid down in January 2018 and expected for delivery in 2024.⁷

Ship Biographies

Challenger-Class

Singapore possesses two Challenger-class diesel-electric attack submarines. These submarines are 51 meters long with a 6.1-meter-wide beam and can travel up to 16 knots when submerged. With its teardrop-shaped hull design and X-rudder configuration, the Challenger-class has improved underwater maneuverability, albeit with a limited diving depth of only 150 meters (compared to 300 meters for Archer-class submarines). Their weapons systems are capable of firing modern wire-guided torpedoes.⁸

Archer-Class

Singapore possesses two Archer-class diesel-electric attack submarines. These submarines are 60.5 meters long with a 6.1-meter-wide beam and can travel up to 15 knots when submerged. They feature Stirling Mk 3 AIP technology to enhance stealth and endurance capabilities.⁹ The vessels were originally designed to operate in the cold waters of the Atlantic; however, they have since undergone the process of ‘tropicalization’ which included the installation of corrosion-resistant piping and valves, marine growth protection systems, and additional cooling.¹⁰ The two Archer-class submarines have an advanced sonar system, the DCNS SUBTICS combat data system, and a pressurized diver’s lockout to facilitate special forces operations. Additionally, these have a new flank array sonar that was developed by Singapore’s Defence Science and Technology Agency and ST Electronics. Their weapons systems are capable of firing WASS Black Shark heavyweight torpedoes.¹¹

Invincible-Class

Singapore plans to possess four Invincible-class submarines, manufactured by the German shipbuilder ThyssenKrupp Marine Systems.¹² These submarines will be 70 meters long with a 6.3-meter-wide beam and can travel up to 15 knots when submerged. They feature air-independent propulsion based on Fuel Cell technology that allows them to be submerged for longer. They will also feature a combat system designed by Atlas Elektronik and ST Electronics.¹³ Their weapons systems will include eight torpedo tubes of 533 millimeters, which will be capable of firing heavyweight torpedoes. ¹⁴

Imports

Singapore operates submarines imported from Sweden. It has also placed orders for submarines from Germany.

Exports

Singapore is not an exporter of submarines.