Nangala began torpedo exercises in northern Bali on Wednesday. Shortly after the start of the exercise, the submarine was lost. Oxygen was on board for the crew until Friday night. In a race against time, the Indonesian Navy searched for Nanggala with the help of Australia, the United States, Malaysia, Singapore and India. Now Indonesian Marshal Hadi Tjjanto mentioned that the wreck has been found.
On Saturday morning, a submarine-like object was discovered with sonar equipment. Debris and objects indicating Nanggala were found in the water, such as torpedo gear, lubricant for binoculars, radiator tube and prayer rugs. The hope of the survivors was already gone by then. Not only was the oxygen on board depleted, the boat was also at an altitude of 850 meters, while it was only able to dive 500 meters. Floating objects refer to the structure being cracked by water pressure at a great depth.
The cause of the shipwreck is unknown. Nanggala must quickly and suddenly sank because the crew had stopped sending distress signals. The battery may have exploded or the boat may have been flooded due to tube malfunction. If the submarine is making water, then the submerged cabin can be protected with a waterproofing door. But if this fails due to a technical malfunction or an explosion on the boat, the boat can quickly sink. The KRI-Nanggala 402, powered by a diesel engine, was built in Germany in 1977 and completely overhauled in South Korea in 2012.
Submarine accidents are relatively rare, but often catastrophic. In 2000, the Russian submarine Kursk sank in the Barents Sea after explosions on board. Most of the crew were killed on the spot, but 23 men later died due to lack of oxygen.
In 2017, an Argentine submarine disappeared in the Atlantic Ocean. The wreck was found nearly a year later at a depth of 800 meters. In 2005, seven crew members of a small Russian submarine were rescued three days after their boat tripped in fishing nets and cables in the Pacific Ocean. They only had an oxygen supply of six hours.