Russia’s first Borey class ballistic missile nuclear submarine, the Yury Dolgoruky, was officially commissioned into the Russian Navy on Thursday, January 10, according to RIA Novosti.

Russian Defense Minister Sergei Shoigu attended the flag hoisting ceremony at the Sevmash shipyard in Severodvinsk in northern Russia.

The signing of the acceptance act by the Defense Ministry took place on December 29.

The Borey class submarines are expected to form the core of Russia's strategic submarine fleet, replacing the aging Project 941 (NATO Typhoon class) and Project 667 class (Delta-3 and Delta-4) boats. Russia is planning to build eight Borey and Borey-A class subs by 2020.

A Borey class strategic submarine is 580 feet (170 meters) long, has a hull diameter of 42 feet (13 meters), and a crew of 107, including 55 officers, a maximum depth of about 1,500 feet (450 meters) and a submerged speed of about 29 knots.

All the Borey class strategic submarines carry up to 16 Bulava ballistic missiles with multiple warheads.