Singapore has launched its fourth Type 218SG Invincible-class submarine, christened the RSS Inimitable and designed specifically for operations in Singapore’s trade-congested waters, according to multiple media sources.
Launched at the Thyssenkrupp Marine Systems (TKMS) shipyard in Kiel, Germany, the submarine was designed with a low signature and air-independent propulsion system (AIP) for long underwater endurance. With a length of about 70 meters and a displacement of around 2,000 tons, the Invincible-class is currently the largest submarine built in Germany.
The RSS Inimitable will be handed over in 2025 after intensive testing. The submarine’s launch follows the launch of the RSS Invincible in 2019 and the double launching of the RSS Impeccable and RSS Illustrious in December 2022.
TKMS and Singapore’s ST Engineering signed a Memorandum of Understanding (MOU) to jointly enhance the capabilities of Singapore’s Type 218SG submarines over their operational lifetimes.
Singapore’s submariners have undergone rigorous training to prepare for all scenarios while aboard the RSS Inimitable. The objective is to train and drill the crew until competent handling of the submarine’s subsystems becomes muscle memory.
To train the RSS Inimitable’s crew, a virtual procedural trainer (VPT) replicated about 12 million parts of an Invincible-class submarine in software, linking with other simulators such as a combat trainer, steering and diving trainer system, and a new maintenance trainer.
The Invincible-class boats are the most advanced submarines in Southeast Asia, representing a significant qualitative and quantitative advantage over models operated by other regional navies. Singapore operates eight submarines while Malaysia has two Scorpene-class boats and Indonesia four Type 209 boats.
Naval Technology says the Type 218SG is custom-made for Singapore’s particular naval needs. It has advanced capabilities, high automation levels, significant payload capacity, improved underwater endurance over the previous Archer and Challenger-class submarines and ergonomics optimized for the Asian physique.
The new Type 218SG submarines are designed with features similar to those of their predecessors, the Type 214 and Type 212A, such as X-rudders. These features allow them to maneuver easily in shallow waters.
They will also have modern combat systems, including eight 533mm torpedo tubes and a multi-purpose lock in the bow section for launching torpedoes, missiles, and special forces assault teams. There is also an option to integrate vertical multi-purpose locks for launching missiles vertically.
The Type 218SG has advanced sensors to enhance situational awareness in shallow and congested waters. Next-generation automation and sense-making systems will aid in making quick decisions.
Notably, the boats are equipped with lithium-ion battery AIP and are capable of speeds of over 10 knots surfaced and more than 15 knots submerged. Its AIP system allows it to stay submerged for approximately 50% longer than preceding Archer-class submarines, enabling it to stay underwater for 4-6 weeks without snorkeling.
Singapore’s submarine program is more advanced and capable than its neighbors and plays critical military and naval diplomacy roles.
In the 2018 book “Naval Modernization in Southeast Asia, Part Two”, Collin Koh Swee Lean mentions that while small navies usually cannot afford to operate submarines due to the complexity and costs involved, Singapore uses technology as a force multiplier to overcome manpower limitations.
He argues Singapore’s “lean and mean” submarine force serves as a credible deterrent for interdicting enemy forces in Singapore’s wide-reaching waters, the crucial Malacca Strait chokepoint as well as the South China Sea.
On submarine capability development, Koh says that while Singapore’s domestic politics and economics do not significantly influence the direction of its submarine program, its tech-savvy population and high-tech defense industry are major plus factors.
However, he points out that Singapore’s neighborhood may be a limiting factor as it angles to demonstrate its submarine program is purely defensive and has no ill-intent. In that connection, he notes that while Malaysia and Vietnam have acquired SM-39 Exocet and Klub-S submarine-launched anti-ship/land attack missiles, Singapore has not followed suit.
Koh notes that Singapore has offered to share its submarine rescue capabilities by signing Memoranda of Understanding (MOU) with Vietnam and Indonesia, highlighting the diplomatic aspect of its submarines.
At the same time, Singapore’s submarine program, alongside other defense acquisitions, provides an important insurance policy in the event of a regional or global conflict.
In March 2024, The Wall Street Journal (WSJ) noted that despite Singapore being roughly the size of New York and being at peace with its neighbors, it is one of the world’s most militarized countries, spending US$11.7 billion on defense in 2022.
The report also notes that Singapore’s per capita defense spending is among the highest worldwide and possibly the most densely defended of any global country, with more troops, tanks and aircraft per square kilometer than any other nation.
Singapore’s founding Prime Minister Lee Kuan Yew said if Singapore were to survive, it should become a “poisonous shrimp” with a military so powerful that larger adversaries would think twice before attacking.
From an economic perspective, WSJ notes that Singapore sees its defense spending as a signal to foreign investors that the country can be defended and that investments are safe.
While Singapore may be at peace with its neighbors, US-China tensions over Taiwan have prompted Singapore to boost its defense spending. Singapore’s Defense Minister Ng Eng Hen has recently stated that the risk of a regional or even global conflict for the next decade has become “non-zero.”
While Singapore has sought to balance its relationship with the US and China, the US can use Changi Naval Base and Changi Air Base as a transit point for its aircraft carriers in the South China Sea, potentially making Singapore a target during a US-China conflict over Taiwan.