Russian nuclear sub in final trials

The Russian Navy's newest ballistic missile-equipped, nuclear-powered strategic submarine Project 955A Borei-A class, Knyaz Vladimir, has headed out for its final sea trials.

"On Tuesday evening, the cruiser set off for the White Sea from Severodvinsk for final trials," the press office of the Russian Northern Fleet said in a statement on Wednesday.

The trials will last several days, first in the surfaced and then in the submerged position.

The nuclear-powered submarine was originally set to formally join the Northern Fleet in 2017, but that schedule repeatedly slipped due to technical issues.

The submarine has undergone state trials, according to the Russian Defense Ministry.

In autumn last year, it test-fired a new RSM-56 Bulava nuclear-armed, submarine-launched ballistic missile.

Being as quiet as possible is essential for the survival of any submarine and is particularly important for the Boreis, which are a key component of Russia's second-strike nuclear deterrent.

The Russian Navy presently has three Project 955 Borei class submarines in service, the first of which became operational in 2013.

Data from Russia's Defense Ministry shows that the Knyaz Vladimir is less noisy, and features improved maneuvering, depth and armament control systems.

Currently, three Project 955 nuclear-powered subs are operational in the Russian Northern and Pacific Fleets.

These submarines are also the only ones in the Russian Navy that carry the Bulava ballistic missile.

According to the Russian Navy, the Knyaz Vladimir is an improved Project 955A strategic missile-carrying underwater cruiser, and represents the fourth generation of nuclear-powered subs built for the navy.

Meanwhile, the new submarines are significantly different externally from their predecessors, notably with the streamlining of the hull to remove a boxlike superstructure around the missile tubes and the revised shape of the sail. The rudders and vertical end-plates are also updated.

All of these features make the submarine more efficient and maneuverable above and below the waves, and help reduce its acoustic signature.

The submarine began its sea trial as the Kremlin made clear recently that it looks to modernize its strategic arsenals.

According to a report carried by Russian state news agency Tass, a contract has been signed to build two more missile-carrying underwater cruisers as part of this project, and there are also plans to build two more Borei-A subs.