Russia’s Sevmash shipyard will float out a third 'Borey-class' strategic nuclear submarine, the 'Vladimir Monomakh' at year's end. 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 plans to build eight Borey and Borey-A class subs by 2020, reports Ria Novosti. Two Borey class vessels, the Yury Dolgoruky and the Alexander Nevsky, have been already built and are undergoing sea trials.