U.S. Navy Sends Deep-Dive Unmanned Recovery Vehicle to Search for Argentine Sub

The U.S. Navy’s Cable operated Unmanned Recovery Vehicle (CURV), in this 2015 photo, is a 6,400-pound Remotely Operated Vehicle (ROV) that is designed to meet the U.S. Navy’s deep ocean salvage requirements down to a maximum depth of 20,000 feet of seawater. US Navy Photo The U.S. Navy is providing deep-dive search and recovery assistance to the Argentine Armada as the international effort continues scanning the depths for remains of its missing submarine.

Thursday afternoon , an Argentine spokesman announced there was no longer any hope of rescuing the 44 sailors onboard the ARA San Juan — missing for more than two weeks — and was focusing all efforts on locating the wreckage.

Argentine officials believe San Juan’s last known location was right at the edge of the continental shelf. Anticipating the sub could have entered a deep uncontrolled dive, the U.S. Navy sent to Argentina a Cable operated Unmanned Recovery Vehicle (CURV) 21 which can dive to 20,000 feet below the sea surface, according to a Navy spokesperson.

The search for the sub has focused on an area near where an explosion was detected having occurred shortly after San Juan’s final communication. The explosion, analyzed by U.S. and international nuclear test monitors, occurred at about the point where the continental shelf drops-off into deep ocean, according to the Argentine Armada. Some naval experts believe the explosion could really have been an implosion of the sub diving to a depth beyond its limit. ARA San Juan (S-42) The CURV is a 6,400-pound Remotely Operated Vehicle (ROV) equipped with continuous transmission frequency modulation (CTFM) sonar for target detection and a high-resolution digital still camera, black and white and color television camera. It arrived in Argentina on Friday morning, and was being loaded onto a ship to be transported to the search area by afternoon, according to a U.S. Navy spokesperson.

The two Navy Boeing P-8A Poseidon aircraft that were part of the search have returned to their home bases. Also, the Navy’s undersea search and rescue teams started packing their equipment on Friday to return to their home bases, according to a Navy spokesman.

Even if San Juan is ultimately located, chances are naval experts will never fully know what happened, said defense consultant, and U.S. Naval Institute Combat Fleets of the World author Eric Wertheim.

“When you look at the Thresher , we still don’t have a lot of answers,” Wertheim said, referring to the 1963 sinking of nuclear attack submarine USS Thresher (SSN-593) which killed 129 crew members. Argentine Armada Image According to the last communication received by the Argentine Navy from San Juan , the submarine experienced a short-circuit in its forward battery compartment after sea water entered through the snorkel. Smoke and possibly fire occurred, but the sub announced it intended to continue to port submerged.

Wertheim said one of the questions investigators will likely try answering is why San Juan didn’t remain on the surface.

“You could have a release of chlorine gas. Fire is a tremendous risk on submarines,” Wertheim said. […]