Summary: The Invincible-class, built by ThyssenKrupp Marine Systems of Germany, boasts cutting-edge features like extensive automation, large payload capacities, and enhanced underwater endurance. Singapore’s Navy currently operates three of these submarines, with another under construction, aiming to replace older models and bolster defense capabilities amid regional tensions.

Singapore's Secret Weapon: The Invincible-Class Submarine in the Indo-Pacific Power Play

As Beijing asserts itself in the Indo-Pacific, greater attention is turning to the capabilities of the region’s lesser militaries. Singapore is among the nations the U.S. might deputize to help counter Chinese influence in the region. 

Singapore is not known for its military might, and you have probably never heard of the Invincible-class submarine, also known as the Type 218SG, in service with the Republic of Singapore Navy (RSN).

Introducing the Invincible-Class

The RSN has completed three Invincibles, with one more on the way. The vessels are all ordered from the German-based naval conglomerate ThyssenKrupp Marine Systems (TKMS). The Invincible class is a custom version of the export-oriented Type 214 submarine. Among its attributes are extensive automation, a large payload capacity, enhanced underwater endurance, and fantastic ergonomics.

Two of the Invincibles were ordered in 2013, and two more in 2017. The RSN wanted the Invincibles to replace its Challenger-class and Archer-class subs. At present, the first-in-class Invincible is being used for training, while the second in class, Impeccable, is undergoing sea trials.

The Invincible’s Specifications

The attack submarine measures 229 feet long with a 20-foot beam. When submerged, the Invincible class displaces 2,200 long tons. The diesel-electric propulsion system relies on two 120-kilowatt PEM fuel cells, which can propel the vessel at a top speed of 20 knots when submerged. The Invincible can operate for 4-6 weeks submerged, without snorkeling.

TKMS fully customized the Invincible to meet the RSN’s requirements, which included naval operations in littoral waters, guarding sea lines of communication, intelligence-gathering, and special operations.

The Invincible has multiple unique features, including an X-shaped rudder configuration, similar to that found on Israeli submarines, which improves maneuverability in the shallow waters of the Strait of Malacca and the South China Sea; a fuel-cell-powered air-independent propulsion module for charging lithium-ion batteries, which allow the submarine to stay submerged about 50% longer than the Archer class; and a Horizontal Multi-Purpose Airlock that can be used for launching torpedoes, special operations personnel, divers, and submarine-launched cruise missiles.

Extreme attention was paid to ergonomic details while designing the Invincible class. Accordingly, the vessel has air conditioning, enlarged living quarters, additional showering facilities, individual on-sharing bunk beds, personal media entertainment systems, toilet cubicles, additional storage space, and equipment that has been personalized to the individual sailor. 

Additionally, the Invincible is highly automated. The Combat Management System, an Atlas Elektronik/ST Electronics product, helps the crew operate the submarine on three four-hour shifts (instead of the standard two six-hour shifts). The advanced automation allows the vessel to sail with just 28 sailors – fewer than any other conventional submarine – and just 10 need to be on duty at any given time.  

While it is not on par with modern American submarines, the Invincible class is a capable, modern vessel that promises to augment the RSN’s underwater capabilities. This will be vital if China continues to press its territorial claims aggressively throughout the Indo-Pacific. 

About the Author: Harrison Kass 

Harrison Kass is a defense and national security writer with over 1,000 total pieces on issues involving global affairs. An attorney, pilot, guitarist, and minor pro hockey player, Harrison joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. Harrison listens to Dokken.

The image is a Creative Commons Photo of a Germany Type 212A Submarine.