Indonesia in race against time in search for missing submarine as oxygen runs low

Indonesian navy ships continued a desperate search for a submarine that has most likely sunk too deep to retrieve, giving scant hope for the survival of the 53 people on board.

Authorities said oxygen in the submarine would run out by early tomorrow.

The diesel-powered KRI Nanggala 402 was participating in a training exercise on Wednesday when it missed a scheduled reporting call.

Officials reported an oil slick and the smell of diesel fuel near the starting position of its last dive, about 96 kilometres (60 miles) north of the resort island of Bali, though there was no conclusive evidence that they were linked to the submarine.

Indonesia’s navy chief of staff, Adm Yudo Margono, told reporters rescuers found an unidentified object with high magnetism at a depth of 50 to 100 metres (165 to 330 feet) and that officials hope it’s the submarine.

The navy believes the submarine sank to a depth of 600-700 metres (2,000-2,300 feet), much deeper than its estimated collapse depth.

Ahn Guk-hyeon, an official from South Korea’s Daewoo Shipbuilding and Marine Engineering, which refitted the vessel in 2009-2012, said the submarine would collapse if it goes deeper than around 200 metres (655 feet) because of pressure.

He said his company upgraded much of the submarine’s internal structures and systems but lacks recent information about the vessel.

Frank Owen, secretary of the Submarine Institute of Australia, also said the submarine could be at too great a depth for a rescue team to operate.

“Most rescue systems are really only rated to about 600 metres (1,970 feet),” he said.

“They can go deeper than that because they will have a safety margin built into the design, but the pumps and other systems that are associated with that may not have the capacity to operate.”  

Mr Owen said the Indonesian vessel was not fitted with a rescue seat around an escape hatch designed for underwater rescues.

He said a rescue submarine would make a waterproof connection to a disabled submarine with a so-called skirt fitted over the rescue seat so that the hatch can be opened without the disabled submarine filling with water.

Mr Owen said the submarine could be recovered from 500 metres (1,640 feet) without any damage but couldn’t say if it would have imploded at 700 metres (2,300 feet).

In November 2017, an Argentine submarine went missing with 44 crew members in the South Atlantic, almost a year before its wreckage was found at a depth of 800 metres (2,625 feet). In 2019, a fire broke out on one of the Russian navy’s deep-sea research submersibles, killing 14 sailors.

Indonesian President Joko Widodo asked all of the country’s people to pray that the submarine and crew could be found. 

Neighbouring countries are rushing to join the complex operation.

Rescue ships from Singapore and Malaysia are expected to arrive between tomorrow and Monday.

The Indonesian military said Australia, the US, Germany, France, Russia, India and Turkey have also offered assistance. South Korea said it too had offered help.  

Indonesia’s navy said an electrical failure may have occurred during the dive, causing the submarine to lose control and become unable to undertake emergency procedures that would have allowed it to resurface. It was rehearsing for a missile-firing exercise, which was eventually cancelled.

The German-built submarine, which has been in service in Indonesia since 1981, was carrying 49 crew members, its commander and three gunners, the Indonesian Defence Ministry said. It had been maintained and overhauled in Germany, Indonesia and most recently in South Korea.

More than 60 of the Type 209 class submarines have been sold and have served in 14 navies around the world, ThyssenKrupp Marine Systems spokesperson Eugen Witte said.  

Indonesia, the world’s largest archipelago nation with more than 17,000 islands, has faced growing challenges to its maritime claims in recent years, including numerous incidents involving Chinese vessels near the Natuna islands.