Orion

The first ships with 343 mm guns, the Orion-class battleships, known as super-dreadnought, were built under the 1909 program. Their distinguishing features were the increased displacement and the absence of turrets near the sides. HMS Orion entered service in 1912 as the flagship of the 2nd Battleship Squadron of the Home Fleet, where she served during World War I. The ship participated in the Battle of Jutland. She was decommissioned in accordance with the Washington Naval Treaty in 1922.