What is the largest submarine in the world?

As of 2014, the world's largest submarine is the Russian Navy's Typhoon Class submarine with a submerged displacement of more than 48,000 tonnes. Each Typhoon is 175 meters long with a beam length of 23 meters and draught length of 12 meters.

Typhoons are powered by two nuclear water reactors, two steam turbines and four turbogenerators. The second-largest submarine is another Russian submarine called the Borei Class with a submerged displacement of 24,000 tonnes. The third-largest submarine, and the largest ever built for the United States, is the Ohio Class used by the US Navy, which has a submerged displacement of 18,750 tonnes.