Fears rise for missing submarine after ‘oxygen deadline’ passes

The hopes of finding and saving dozens of people on board a missing Indonesian submarine are fading fast as its oxygen supply is now believed to have run out.

There is still no sign of the missing KRI Nanggala 402 crew as the deadline for its oxygen – enough to last three days after losing power – was expected to have been passed earlier on Saturday.

Indonesian officials said on Friday that the submarine would only have enough air to last until around dawn on Saturday if equipment was functioning properly.

“So far we haven't found it ... but with the equipment available we should be able to find the location,” Achmad Riad, a spokesman for the Indonesian military, told a news conference.

Koh said the assumption that the submarine had 72 hours of oxygen was optimistic given the submarine's limited ability to generate oxygen due to its conventional power generation.

“So there's a possibility ... oxygen might have already run out,” said Koh.

It is believed there are 53 people on board the vessel, which includes 19 more people on board than would usually be.

Experts claim that the search and rescue operation, involving hundreds of military, is fast reaching the point where it is “fruitless” and that the incident “has all the making of a major tragedy”.

Frank Owen, secretary of the submarine institute of Australia, explained the passing of the oxygen deadline acted as a “line in the sand” for the authorities to recognise search and rescue was “fruitless”.

He told BBC Radio 4’s Today programme: “Without some defined point, people will tend to keep on hoping against hope that people might still be alive.

“The consumption of oxygen is based on a very average usage and if you actually were sitting in a disabled submarine, you would be lying down and minimising all exertion so that you reduce your oxygen consumption.”

He added: “For this submarine, the only option was for it to be abandoned at the surface or for it to have found some seabed less than 180 metres deep so they could escape.

“It’s not fitted with the rescue seat to allow it to have an interface with a rescue vehicle.

“This has all the makings of a major tragedy, made all the worse by the fact it had an extra 19 people on board – probably most of them trainees because they are building up their numbers in the Indonesian navy ... so the future is even more bleak.”

The United States is deploying a P-8 Poseidon aircraft to assist, while the Indonesian navy said it was sending search helicopters and ships to the area.

Australia has also deployed a sonar-equipped frigate with a helicopter to help the hunt, while navy officials said vessels are en route from India and Singapore, as concerns grow that the submarine might have been crushed by water pressure.

Contact was lost with the 44-year-old submarine on Wednesday as it prepared to conduct a torpedo drill, off Bali.

Indonesia's navy said it was investigating whether the submarine lost power during a dive and could not carry out emergency procedures as it descended to a depth of 600-700 metres (1,968-2,296 feet), well beyond its survivable limits.

Additional reporting by Reuters