US Releases Data Related to Sub Collision

The US National Transportation Safety Board (NTSB) on Friday released data on the surface and undersea movements which led to the February 9 collision between US submarine Greeneville and Japanese fishing vessel Ehime Maru off Hawaii, the Associated Press reported.

NTSB data on the last 15 minutes before the tragic collision show that the 190-foot (57-meter) Japanese trawler was traveling in a south-southeast direction at 12.5 mph (20 kph), nearly parallel to southbound course of the submerged 360-foot (108-meter) submarine, the AP said.

The nuclear-powered submarine passed the Ehime Maru, but then reversed course to prepare an emergency ascent drill, which was a demonstration for 16 civilian guests aboard the submarine.

When the two vessels were about two miles (3.2 kilometers) apart, the submarine made a series of zigzag turns, continuing in a north-northwest direction before ascending to an initial periscope depth five minutes before the impact.

After one and a half minutes, the Greeneville descended, going the same direction as the Japanese boat. The submarine reached 405 feet (121.5 meters) in two minutes and at the same time turned its course northward.

The Greeneville then shot to the surface in 50 seconds, coming up under the Ehime Maru.

With its bottom ripped by the submarine, the Ehime Maru sank within minutes, leaving nine of the 35 people aboard missing.

The information released by the NTSB was based on preliminary tape of the Greeneville's recorded sonar data and its own navigation data for the 10 minute period before the collision.






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