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Commentary: Indonesia submarine tragedy exposes painful realities of international rescue operations

The tragic loss of KRI Nanggala lays bare the limits to international cooperation on submarine rescue, says RSIS’ Collin Koh.

SINGAPORE: Submarines continue to capture the imagination of both naval planners and the general public alike.

They are seen as the force multiplier, especially for weaker militaries, serving as an asymmetric counter to a stronger adversary.

The “Silent Service”, as submarine forces are commonly nicknamed, is considered the elite of any navy, constituting a significant peacetime deterrent and a combat capability.

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Over the decades, as Southeast Asia embarked on a spate of submarine proliferation, there had been warnings about the potential likelihood of incidents.

These span diplomatic ones such as the infamous “Whiskey on the Rocks” episode that saw a Soviet submarine grounded on Swedish shores back in 1981, and unfortunate accidents such as the collision between US submarine Greeneville and Japanese vessel Ehime Maru in 2001.

Prior to last week, the most recent submarine mishap took place in February in Northeast Asia, when the Japanese submarine Soryu scraped the hull of a commercial vessel in the Pacific Ocean, while surfacing off Shikoku.

Fortuitously, while the submarine suffered damage, including a communications blackout, and three crew members were slightly injured, it returned safely to base.

The Indonesian submarine KRI Nanggala was not as lucky.

The boat lost contact with shore authorities around the time it last dived to get into position for a torpedo live-firing. After three days of intensive search, by which time the submarine is thought to have already depleted its oxygen supply, Indonesian authorities delivered the bad news: All 53 crew members are confirmed dead. Debris from the Nanggala was recovered.

An undated underwater photo released on Apr 25, 2021 shows parts of submarine KRI Nanggala 402 that sank in the Bali Sea, Indonesia. (Photo: Indonesian Navy via AP) Indonesia Submarine

The wreckage was found and visually verified on the seabed over 800m deep, well past the designed maximum diving depth of the submarine.

This latest tragic loss is the first such submarine mishap in Southeast Asia.

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To Indonesia’s credit, their response was swift and decisive. Cognisant of its resource limitations, the Indonesian military quickly sought foreign assistance through the International Submarine Escape and Rescue Liaison Office (ISMERLO) channel.

It invoked the Arrangement between the Republic of Singapore Navy and the Indonesian Navy Concerning Submarine Rescue Support and Cooperation signed in 2012.

Indonesian authorities fully understood the overarching priority to quickly locate the lost submarine and mount a rescue effort for any survivors on board.

This stands in sharp contrast to Moscow’s initial reaction. When the Russian submarine Kursk was lost in August 2000, Russia opposed foreign assistance on grounds of national security until it was too late to mount any meaningful rescue for the trapped survivors.

Crew on board a rescue ship pay respects to the fallen crew of KRI Nanggala with a moment of silence. (Photo: AP) Indonesia Submarine

International response to Jakarta’s call for help had come as quickly too – with Australia, India, Malaysia and the United States among foreign governments that dispatched assets.

Immediately upon receipt of the Indonesian request, Singapore dispatched the navy’s submarine support and rescue vessel MV Swift Rescue, which mounts a Deep Search and Rescue 6 deep-submergence rescue vehicle (DSRV) that very afternoon on Apr 21.

While the rescue has now turned into a recovery operation, owing to the devastating news over KRI Nanggala, the incident aptly demonstrated the usefulness of established international submarine emergency response procedures.

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More pertinently perhaps, it highlighted the utility of regional cooperation – as seen in the outpouring of support and offers of assistance.


International cooperation in submarine emergency response will always be important. Foreign militaries may possess the requisite capabilities one does not have that could be critical to any submarine emergency situation. 

But submarine emergency response is essentially also a race against time.

The Deep Search and Rescue Six submersible vessel is launched from the MV Swift Rescue. (Photo: Facebook/Valleryan Valleryan)

In this respect, international cooperation, while important, does have limitations. It could be the tyranny of geographical distance between the foreign country sending a submarine rescue ship to the site of mishap.

Even if a foreign country airlifts a DSRV to the country concerned, this would require an adequately-equipped vessel of opportunity in the port nearest to the site to be available. Time will be needed to outfit this vessel before deployment.

Having to sail a distance of over 1,500 km from Changi Naval Base to the site off Bali, under the best circumstances, the Swift Rescue would only arrive no earlier than the late afternoon or evening of Apr 23.

As the oxygen supply on board the Nanggala was estimated to run out by 3am of Apr 24, there was only a very limited window for rescue once the Swift Rescue gets into position.

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There are also other factors working against such an effort – the weather and sea conditions in particular.

If anything, the Nanggala episode shows the need for submarine-operating and aspiring navies to more seriously think about the supporting infrastructure that backstops safe and effective submarine operations.


Still, the Nanggala tragedy is not likely to put a damper on enthusiasm among regional navies in acquiring submarines.

Apart from Indonesia, Malaysia is thinking of expanding its fleet, Thailand is building one from scratch, and the Philippines has submarine plans in the pipeline.

Personnel from the Republic of Singapore Navy casting off the lines for MV Swift Rescue. (Photo: Facebook/Ng Eng Hen)

It has become clear that submarine capabilities should not solely be just about the submarines themselves.

Navies that seek to establish a credible, safe and effective underwater capability will have more than submarines to worry about. The after-sales life cycle of the submarines and their essential maintenance, repairs and overhauls schedules continue to be critical factors to consider from the fiscal, operational and safety point of view.

Given exorbitant costs involved, longer service for modern submarines today are expected, even if past their average life span. Training of the crew and shore-based supporting personnel will also continue to be crucial

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But for navies to respond to emergencies involving their submarines, they cannot merely rely on foreign assistance.

A submarine supporting infrastructure must include an emergency response capability - an additional expense for cash-strapped navies.

Yet through the decades of submarine proliferation across the oceans in this region, there has been an uneven emphasis on emergency response capabilities.

Navies in Northeast Asia – such as China, Japan and South Korea – as well as Australia, possess such capabilities as an organic part of their submarine forces. In Southeast Asia, only Malaysia, Singapore and Vietnam have such capabilities out of the five submarine-operating navies.

The Hai Lung SS-793 diesel-electric submarine emerges from underwater during a during a drill near Yilan naval base, Taiwan April 13, 2018. (Photo: REUTERS/Tyrone Siu/File Photo)

Vietnam is an interesting case. While its navy was in the process of building its fleet of six Kilo class submarines purchased from Russia, Vietnam signed a submarine emergency response agreement with Singapore in 2013 – equivalent to the one signed between Indonesia and Singapore the year before.

But this did not stop Vietnam from acquiring its own submarine rescue vessel, the Yet Kieu, commissioned in late 2019.

Having an organic submarine emergency response capability will come handy in times of a mishap.

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Furthermore, in today’s context when it is increasingly challenging to recruit sufficient manpower to crew submarines – a hazardous job compared to what surface warship crews are subjected to – it is necessary to win the confidence of people who work inside these steel cylinders.

Submariners expected to put their lives at stake would also expect assured help should they ever encounter distress out at sea.

Collin Koh is research fellow at the Institute of Defence and Strategic Studies, a constituent unit of the S Rajaratnam School of International Studies based in Nanyang Technological University, Singapore.

Source: CNA/sl