Internal wave: scary thing that sank the Indonesian submarine
Did Indonesian Navy submarine KRI Nanggala fall victim to powerful internal waves in the sea off Bali? Photo / AP
It is believed that a frightening unseen natural force dragged an Indonesian submarine deep into Balinese waters last week.
KRI Nanggala 402 lost contact after submerging during a routine training exercise in the Bali Sea last Wednesday.
After a frantic five-day search, the attack vessel was found by rescuers cracked on the seabed at a depth of 838m. All 53 crew members were deceased.
After finding objects inside the submarine during the search, questions began to arise as to how the manned submarine could disappear so quickly.
How did the KRI Nanggala 402 disappear?
Indonesian military officials now suspect that the submarine was hit by an internal solitary wave, a powerful force generated when a volume of water is pushed through a relatively smaller passage.
According to Nikkei Asia, the density of the waters off Bali and in the nearby Lombok Strait likely triggered a “massive moment” of force, with enough downward momentum to suck the submarine down. in a matter of moments.
What are internal waves?
Internal solitary waves are powerful, hard to detect currents that pose a major threat to submarines and can put great pressure on offshore oil platforms.
Satellite images captured by NASA in 2016 show an internal solitary wave off the Lombok Strait.
The space agency explained that internal waves occur when “the interface between the layers is disturbed, for example when the tidal flow passes over irregular ocean floors, ridges or other obstacles.”
As the Lombok Strait is a relatively narrow passage between the Pacific and Indian Oceans, the tides develop a “complex rhythm” but “tend to combine about every 14 days to create an unusually strong tidal flow”.
The combination of ocean topography, strong currents and moving water between the two oceans makes the region famous for its generation of intensive internal waves.
Waves are difficult to photograph and cause only minor ripples on the ocean surface, despite their potential to create a strong underwater drag.
‘There was nothing they could do’
Iwan Isnurwanto, commander of the Navy Command and Staff School, said images of a suspected internal solitary wave in the area where the submarine went missing were produced by the Japanese weather satellite. Himawari 8.
“There was nothing they could do, no time to do anything … if the submarine was shot down by such a wave,” Isnurwanto told a neighborhood press briefing. general of the navy in Jakarta.
âHe probably tilted (down), which rolled all of the crew (to the bottom of the ship).
“We need to investigate further, but that is probably what happened.”
Other theories on why the submarine sank
Prior to the sinking of the KRI Nanggala, reports suggested that the attack vessel may have suffered a power failure.
The theory came from a provisional analysis submitted by the Navy Information Service and indicated that the submarine was at risk of power failure during the static dive. The analysis warned that the submarine could fall to a depth of 600 to 700 m.
It was suggested that the vessel needed an emergency button to counter the problem.
A former general TB Hasanuddin also suggested that a refurbishment and modernization of the submarine, completed in 2012 in South Korea, may have been poorly completed.
He said that the same year the modernization was completed, there was a failure with the test firing of the torpedo system in the ship, killing three people.
âI suspect that in the results of this repair there are things or constructions that are not correct, so that the KRI Nanggala-402 sank. It’s very unfortunate, âhe said.
The ship was first built in 1978 and had its last refit in 2012, when its depth was increased to 250m.
During the search, crews discovered an oil spill and several objects, including prayer rugs and pieces of the ship’s torpedo tube, hours after KRI Nanggala lost contact. The results raised immediate concern for the well-being of those on board.
It is believed that the water pressure caused the sub to split, through which some of the objects escaped.
The air supply was scheduled to expire at 3 a.m. last Sunday.
Research ships received magnetic signals from the submarine on Sunday morning, and confirmation that the ship was at the bottom of the sea came soon after.
Joko Widodo, President of Indonesia, said the nation was shocked by its first submarine disaster and that the government “expresses our sincere condolences, especially to the families of the crew.”
The discovery of the KRI Nanggala 402 ended a panicked five-day search that involved nations surrounding Indonesia, including the United States and Australia.
A rescue ship, the MV Swift Rescue, was capable of retrieving people underwater, if there were any survivors, reports the Times News Service.
The ship’s crewed submersible is capable of carrying up to 17 people to the surface and has decompression chambers and medical centers.
The KRI Nanggala 402 was one of five submarines in the Indonesian fleet and was refitted in South Korea in 2012.
– With threads