Russia's Nerpa nuclear attack submarine, damaged in a fatal accident during tests in November last year, started on Friday the second stage of new sea trials, a source involved in the tests said.
The vessel resumed sea trials on July 10 in the Sea of Japan following extensive repairs. The first stage of new sea trials was successfully completed on Monday.
"The submarine left dock at the Vostok repair facility in the town of Bolshoy Kamen in the Primorye Territory and headed for the Sea of Japan," the source said.
Some special equipment to check the vessel's performance has been installed on board the submarine and the new trials will last for at least two weeks, according to the Amur shipyard officials.
On November 8, 2008, while the Nerpa was undergoing sea trials in the Sea of Japan, its on-board fire suppression system activated, releasing a deadly gas into the sleeping quarters. Three crewmembers and 17 shipyard workers were killed. There were 208 people, 81 of them submariners, on board the vessel at the time.
Following the repairs, which cost an estimated 1.9 billion rubles ($60 million), the submarine was cleared for final sea trials before being commissioned with the Russian Navy, and will be leased to the Indian Navy by the end of 2009 under the name INS Chakra.
India reportedly paid $650 million for a 10-year lease of the 12,000-ton K-152 Nerpa, an Akula II class nuclear-powered attack submarine.
Akula II class vessels are considered the quietest and deadliest of all Russian nuclear-powered attack submarines.