Moscow, Aug 3 (RIA Novosti) Russia's latest Borey class nuclear submarine, the Yury Dolgoruky, will undergo at least six more sea trials before it is inducted into the Russian Navy, officials said Monday.

The submarine, to be armed with the new Bulava sea-launched ballistic missiles (SLBM), successfully completed its first round of sea trials in the White Sea July 10.

'According to our estimates, the submarine still needs at least five or six sea trials before commissioning,' said Anastasia Nikitinskaya, a spokesperson for Sevmash plant.

The vessel is 170 meters (580 feet) long, with a hull diameter of 13 meters (42 feet), has a crew of 107, including 55 officers, a maximum depth of 450 meters (about 1,500 feet) and a submerged speed of about 29 knots. It can carry up to 16 ballistic missiles and torpedoes.

The construction cost of the submarine totalled 23 billion rubles (about $713 million), including nine billion rubles ($280 million) for research and development.

Two other Borey class nuclear submarines, the Alexander Nevsky and the Vladimir Monomakh, are currently under construction at the Sevmash plant and are expected to be completed in 2009 and 2011.