China's Navy Recovers Components From Sunken Indonesian Sub

The People's Liberation Army Navy (PLA Navy) research vessel Explorer 2 has begun retrieving wreckage from the lost Indonesian submarine Nanggala, including an undeployed life raft module weighing 1,500 pounds.

So far, a small flotilla of three Chinese research and salvage vessels - the submarine rescue ship Yongxingdao-863, the fleet tug Nantuo-195 and the Explorer 2 - have conducted 13 operations at the wreck site, according to state-owned media. The missions have focused on photo and video documentation of the vessel, but they have also retrieved small objects, like the vessel's hydrophone, a wrench and a technical manual, according to the Indonesian Navy. 

The vessel's hull is broken into three main pieces - likely the result of a violent implosion from extreme pressure, according to Indonesian officials. The Indonesian Navy has indicated that it would like to raise the wreckage from its location in the strategically-important Lombok Strait, and the Chinese government nominated its research vessels to assist. 

"Lifting objects under the very deep sea, which is deeper than 800 meters, is a complex problem," said Cao Peng, the commander of one of the Chinese vessels.

The Chinese salvage mission has benefits for Indonesia, but it may also further China's national security objectives, a Chinese defense source told state-owned Global Times. The salvors will have an opportunity to "study the maritime military geography of the area where the submarine was wrecked, as well as expanding the international cooperation and influence of our navy in submarine rescue and salvage," the source said. 

The cause of the sinking is not yet known, but Indonesian officials have ruled out an explosion. At the time that the sub lost contact, it had just received permission to dive for a torpedo exercise. It went missing at 0300 hours local time on April 21, and an aerial search team spotted signs of an oil spill near the location of the dive about four hours later. With the assistance of the Singaporean rescue vessel MV Swift Rescue, Indonesian forces located the wreck site on April 25. Given the depth and the condition of the wreck, all 53 members of the sub's crew are presumed dead.