SINGAPORE – Submarines are often referred to as silent service because of their ability to remain undetected while chasing enemy ships. Submarines have played a crucial role in major conflicts for over a century since the Germans used submarines with devastating effects in World War I.
But the recent sinking of the Indonesian submarine KRI Nanggala 402 has highlighted the dangers associated with operating these complex war machines, designed as “ship killers” that operate over long distances in an unforgiving underwater environment.
The loss of the 53 crew members aboard the Nanggala in April after losing contact during an exercise was the fourth recorded accident since 2000 in which a complete submarine crew was killed.
In 2017, the Argentine submarine ARA San Juan and its 44-strong crew went missing during an exercise off the coast of the country. His wreck was found a year later.
In 2003, a Chinese submarine was in the sea off northeast China when the diesel engine did not shut down when the boat was submerged and all of the oxygen was used up, killing all 70 on board.
The Russian nuclear submarine Kursk sank in 2000 after an explosion in the Barents Sea, with no survivors among its 118 crew.
The many risks to submariners include those arising from the literal high pressure submarine environment that offers wafer-thin margins of error. An incident such as a fire on board or a power failure can quickly escalate and become catastrophic.
So why do Singapore and other Southeast Asian countries continue to acquire and operate these assets while even the smaller regional navies recognize the risks of their investment?
The answer lies in the strategic nature and versatility of these deep-diving predators, which have proven their pedigree in naval history.
While the earliest submarine prototypes date back to the 16th century, they first came to prominence as a military weapon in World War I, when they mainly played the role of trade robbers.
Then the German submarines – short for submarines – sank about 5,000 mostly merchant and civilian ships, which brought important supplies to the British.
During World War II, submarines became more versatile and deadly by adding visual surveillance of enemy shores and the addition of secret agents or special forces to their repertoire, said Ben Ho, a research fellow at the S. Rajaratnam School of International Studies (RSIS).
American submarines, for example, never made up more than 2 percent of the total force of the United States Navy during World War II, but the ships they operated made up, according to Mr. Over 55 percent of all Japanese ships sunk in the Pacific from Don Keith, who wrote the book Final Patrol: True Stories Of World War II Submarines.
In this day and age, Ho said the typical attack submarine is like a Swiss Army Knife charged with a multitude of missions, as opposed to its rarer ballistic missile cousin, whose raison d’etre is nuclear deterrence.
“The submarine is an extremely versatile platform that, through its camouflage and the ability to generate surprises – offers its operator an asymmetrical advantage, even when facing a strong opponent à la David versus Goliath.”
As an example of the strategic importance of submarines, RSIS research fellow Collin Koh said that the sinking of the Argentine cruiser ARA General Belgrano by the British HMS Conqueror in the 1982 Falklands conflict between the two countries had a profound impact on Buenos Aires.
“The Argentine Navy’s surface fleet, including its only aircraft carrier, ARA Vienticinco de Mayo, has been confined to port and made no sorties for the remainder of the conflict,” he said.
Singapore went deep with the commissioning of the RSS Conqueror in July 2000. The Navy of the Republic of Singapore currently operates four refurbished Challenger and Archer class submarines.
They will be replaced by four advanced, purpose-built Type 218SG submarines from the German defense company thyssenkrupp Marine Systems, the first of which will be delivered from next year.
Regional countries such as China, India and South Korea are also planning to expand their submarine fleets.
Closer to home, Vietnam operates the largest fleet in Southeast Asia with six submarines. Indonesia had five before the recent sinking. Malaysia operates two and Thailand has ordered one.
The Philippine Navy has repeatedly campaigned for the establishment of a submarine force. Myanmar was given a Soviet-era submarine by the Indian Navy last year.
Dr. Koh believes even a tiny “token” fleet is important as it could act as a deterrent, although he warned that even a small force could be expensive to acquire, operate and maintain.
He cited the US confrontation with the Libyan regime Muammar al-Gaddafi in the 1980s, when the US Navy worried about its tiny fleet of Soviet submarines despite its poor state of readiness.
Australia is also concerned about the potential challenge Indonesia’s two Cakra-class submarines, including the ill-fated Nanggala, could pose when it led a multinational peacekeeping force in East Timor in 1999, added Dr. Koh added.
“Even a small submarine force would be a worthwhile investment in the eyes of the Southeast Asian navies, which are typically small and weak compared to their stronger regional counterparts,” he added.
Put another way, a submarine is like a mobile minefield that adds uncertainty to an enemy’s planning as it poses an elusive but deadly threat, said Frank Owen, secretary of the Submarine Institute of Australia, who served 31 years in the Royal Australian Navy had served.
Dr. Koh added, “Classical threat perceptions are not necessarily the key or the only engine for finding submarines in Southeast Asia; it is also about catching up with the Joneses, as is the case, for example, in the case of Thailand. ”
“It’s not so much that the neighbors’ submarines pose a real threat, but that if you don’t buy submarines, you can fall behind in building a modern, balanced fleet.”
While hitting beyond their tonnage, submarines are exposed to a wide variety of operational risks, even when usually manned by some of the most elite military personnel, selected through a rigorous process. The greatest risk is collisions, Owen said.
A submarine can almost never be seen from a surface ship, he said. Even when it shows up, the silhouette of a submarine is small.
Underwater it relies on hearing the sounds of other ships, but the sound can be distorted so a sub may not hear anything if it returns from the deep until it’s too late, he added.
In 2001, the US submarine USS Greeneville collided with a Japanese fishing ship while diving, causing the ship to sink and killing nine of the 35 people on board, including four high school students.
Like a warship, a submarine has instruments and sensors to keep it safe even under difficult conditions. But unlike a surface ship that stays afloat as long as the hull is intact, it is inherently less safe.
On a submarine, small mistakes can have catastrophic consequences because emergencies don’t occur in isolation, said Anil Jai Singh, senior vice president at thyssenkrupp Marine Systems.
“One thing leads to another, which can be catastrophic if not dealt with properly and in good time. Sometimes even the best response cannot save a situation that is developing very quickly,” he said.
This means that even a small problem can spiral quickly and cause the crew to lose control of the submarine or the boat to lose neutral buoyancy and sink, said Bryan Clarke of the Washington-based Hudson Institute.
Mr Singh said the two biggest emergencies were either a major flood from a ruptured pipeline or hull damage or a major fire on board that could result in a total power outage, an internal explosion, smoke and suffocation, or a rising water level in the submarine.
Although redundancies are built into critical systems, they can fail, he added.
The high pressure environment means that a hull fracture can create a jet of water many times the force a surface ship could experience, Owen said.
“Any high tide at depth quickly becomes uncontrollable and the weight of the water absorbed into the submarine can quickly exceed the buoyancy that emptying the ballast tanks could provide.”
Mr. Singh, a former Indian Navy submarine operator for 28 years, suggested that in the case of the Nanggala, if she was dived at a conservative speed of 5 knots with a downward angle and loss of power, it would have taken the ship less than three minutes for the ship to enter at a depth of 850 m below the depth where it was found.
“In addition to this total darkness on board, there are still unresponsive emergency systems and the foreboding of the crew that they will quickly fall over the oppressive depth of the submarine.
“These dangers do not differentiate between times of war and times of peace, so the risk is omnipresent when a submarine sets sail.”