A string of countries including Australia is continuing to assist Indonesian authorities in their search for a missing submarine and its 53 inhabitants, who will run out of air at 5:00am AEST on Saturday morning.
Key points:
- Search teams are scouring the ocean floor for signs of life
- The Indonesian Navy has found an object 100 metres below the sea
- An expert in military technology says chances of survival are quite low
The Indonesian Navy’s KRI Nanggala 402 submarine went missing on Wednesday, after it failed to re-emerge from its last reported dive in waters near Bali.
There is mounting concern the 43-year-old vessel may have sunk too deep to reach or recover the stranded 53 crew in time before oxygen supplies run out.
“We will maximise the effort today, until the time limit tomorrow at 3:00am [local time],” military spokesperson Achmad Riad told reporters.
While Indonesian authorities have had their search bolstered by a sonar-equipped Australian warship with a helicopter, there have been no signs of life.
With oxygen due to run out in a few hours, what are the chances of a successful rescue?
Who and what is doing the searching?
Twenty-four Indonesian ships and a patrol plane were mobilised for the search on Friday, with similar large searches made in the past two days.
An American reconnaissance plane was expected to join the search Saturday.
“These two Australian ships will help expand the search area and extend the duration of the search effort,” Australian Navy Rear Admiral Mark Hammond said.
Singaporean and Malaysian rescue ships were also expected in the coming days.
Marcus Hellyer, a senior analyst focussing on defence capability and military technology at the Australian Strategic Policy Institute, told Radio National’s PM that Australia’s vessels were constrained in their ability to help.
“The Sirius is essentially a big oil tanker, so there’s not much you can do except maybe refill ships at sea,” Dr Hellyer said.
What has been found so far?
Indonesian search parties have focused on an area where an oil slick was found after the submarine disappeared.
Indonesia’s Navy Chief of Staff Yudo Margon also said an unidentified object exhibiting high magnetism was located at a depth of 50 to 100 metres, and officials held out hope it is the submarine.
But the navy said it believes that the submarine sank to a depth of 600-700 metres, much deeper than its collapse depth, at which water pressure would be greater than the hull could withstand.
The vessel’s collapse depth was estimated at 200 metres by a South Korean company that refitted the ageing vessel in 2009-2012.
Do we know what caused the accident?
The cause of the disappearance is still uncertain.
The navy said an electrical failure could have left the submarine unable to execute emergency procedures to resurface.
Admiral Margono also suggested oil could have spilled from a crack in the submarine’s fuel tank, or the crew could have released fuel and fluids to reduce the vessel’s weight so it could surface.
But there has been no conclusive evidence the oil slick was from the sub.
What chances are there of survival?
Dr Hellyer said submarine accidents were often “catastrophic”.
In 2000, the Russian nuclear submarine Kursk suffered internal explosions and sank during manoeuvres in the Barents Sea.
Most of its 118 crew died instantly, but 23 men fled to a rear compartment before they later died, most of suffocation.
And 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.
“It is very rare that there are people left alive after an initial leak, explosion, or mechanical fire,” Dr Hellyer said.
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Dr Hellyer said there has only been one successful deep-water submarine rescue in the history of submarine operation, that being the rescue of the USS Squalus in 1939.
The vessel was diving in the North Atlantic near the state of New Hampshire, but sank after a valve failed, flooding the vessel. It sank to a depth of 73 metres.
Crew travelling in an adjacent submarine sounded the alarm and were able to pinpoint the location of the downed vessel, with 33 survivors onboard later rescued.
“They knew exactly where the submarine was, and happened to be near a submarine base,” Dr Hellyer said.
“Fortunately, they were able to save those members of the crew who survived.
“But that is the exception.”
ABC/wires