10 Facts About the Indonesian Submarine That is Known so Far

In the early hours of Wednesday morning (21 Apr), an Indonesia submarine, the KRI Nanggala 402, was carrying out a training exercise in north Bali waters.

Then, less than an hour after its descent, the submarine with 53 crew members on board lost contact and disappeared off the coast of Bali. What’s more, the periscope, which should have been visible, had also vanished.

A search team which included vessels from all over the world came together to look for the lost submarine, but when they did, they learnt the tragic truth.

Here are 10 facts about the disappearance of the KRI Nanggala 402.

1. It Was Conducting a Routine Drill When It Vanished

At about 3:00am on that fateful day, the Nanggala began torpedo drills, with 53 crew members on board.

The training exercise was conducted in waters north of Bali.

It should have been a routine activity for the long-serving submarine, but 45 minutes after it sank into the water, contact with the submarine was lost as sonar pings had gone unanswered.

2. The Submarine is Nearly Half a Century Old & Has Served in Numerous Navies Around the World

The 1,300-tonne Naggala was built by Germany and was first delivered for service in 1981.

It has served in numerous navies around the world, including Greece, India, Argentina and Turkey.

The submarine was 44-years-old when it went missing.

However, it underwent a refit in South Korea in 2012 and was said to be in good condition.

3. Authorities Were Racing Against Time to Locate the Submarine as Oxygen Was Running Out

Like most rescue missions, the authorities were racing against the clock to find the missing submarine and its crew members.

This was because there was a limited amount of oxygen on board the vessel to subsist the crew members.

Officials predicted that even if the submarine had managed to withstand the water pressure, it would only have enough air until dawn on Saturday (24 Apr).

4. There Was an Oil Spill Near Where the Submarine Dived

Rescue teams were dispatched immediately, and they made an alarming discovery later that day.

An aerial search found an oil spill on the surface near where the submarine had dived.

This oil spill could mean two things:

1. There was damage to the submarine’s fuel tank
2. It could have been a distress signal from the crew

Either way, it wasn’t good news.

5. Singapore Sent a Special Rescue Vessel to Indonesia & Obtained Visual Images of the Submarine

Soon after news of the lost submarine broke, several countries offered to join the search effort.

In addition to an aircraft from the US, five vessels from Singapore, Malaysia, Australia, and India joined the search.

Singapore’s vessel—the MV Swift Rescue—is a rescue vessel from the Republic of Singapore Navy (RSN).

According to Navy Chief Admiral Yudo Margono, the MV Swift Rescue’s Remotely Operated Vehicle was deployed at 7:00am.

At around 9:00am, it obtained visual images of the submarine at a depth of 850m.

6. An Escape Suit Was Found Floating in the Waters

Search teams also found a torn bright orange escape suit floating in the dark waters.

Admiral Yudo said the escape suit was usually stored in a box, so the fact that it was found outside meant there was an emergency situation.

“Either they were not able to put the suits on fast enough, or the submarine shook while they were trying to put them on,” he said.

7. When the Submarine Was Found, It Was Cracked Into 3 Parts

When rescue teams obtained visual images of the submarine, they were shocked to discover that it was cracked into three parts on the seabed.

They also found broken remnants of the submarine floating in the water, including hull parts, a vertical rear steer, an anchor, and dive rudder.

Some items were which likely disgorged from the submarine were also found, such as pieces of Muslim prayer mats, special sponges for clearing condensation, and a bottle of grease used to lubricate periscopes.

8. All 53 Crew Members on Board Have Been Declared Dead

Sadly, based on the visual images, officials have concluded that all 53 crew members on board have died.

“Based on the authentic evidence, I declare that the KRI Nanggala-402 has sunk and all the crew have died,” Air Chief Marshal Hadi said.

“They’re the best soldiers… and may the God Almighty reward their good deeds and dedication.”

9. The Submarine May Have Cracked Due to a Power Blackout

While the true cause of the accident is unknown, officials are speculating that it was due to a blackout.

See, the submarine was built to sustain pressure at a maximum depth of around 250 metres.

So, when it descends beyond this depth, the submarine could be badly damaged. In fact, experts previously warned that the vessel could break into pieces if it had sunk to depths as low as 700m.

Officials believe that a power blackout on the submarine may have caused it to lose control and become unable to perform emergency procedures.

Other believe that water somehow flooded the submarine. If that happened, the submarine would sink very quickly, or “like a stone”, as one military analyst said.

10. The Crew May Not Have Died Due to a Lack of Oxygen

Since the bodies of the crew members have not yet been discovered, the cause of their death has not been established.

What is known are the dangers to the human body when it’s stranded in a submarine as atmospheric pressure builds up:

• Ruptured eardrums
• Nitrogen narcosis: nitrogen entering bloodstream at increased pressure, which can result in impaired judgement and loss of fine motor control. Some can even enter a coma and die
• Barotrauma: gases in body organs or structures get compressed
• Decompression sickness: sudden return to normal pressure can lead to the formation of gas bubbles in tissues and blood, which could be life-threatening
• Oxygen toxicity: lung damage from breathing in too much oxygen

As previously stated, the crew members on board could also have died from a lack of oxygen. It’s simply too early to say at this point.

Nevertheless, this incident has rocked the country, especially the loved ones of the crew members. It is the first major submarine accident in Indonesia, which has been working to replace its ageing military equipment.

President Joko Widodo said: “This tragedy shocked us all. Not only the families of the 53 crew members and the navy, but also the entire Indonesia people.”

Fair seas and following winds on your eternal patrol, Heri. I’ll miss you buddy.

RIP Nanggala and crew. pic.twitter.com/OG7AI6OqX6

— Henrik Paulsson (@henrikrpaulsson) April 24, 2021

“We convey our deep sorrow for this tragedy, especially to families of the submarine crew. They were the best sons of the nation, the best patriots who guarded the sovereignty of the country.”

Feature Image: Aerial-motion / Shutterstock.com (Image is for illustration purposes only)