Appreciating the size of a "Really Big Gun" -- 18" of Raw Muscle

[vintage hunter]

U.S.New Jersey, one of the four Arizona class battle wagons (New Jersey, Arizona, Missouri and Wisconsin)

Arizona class? No such thing is there? The New Jersey and her sisters(6 in all) are Iowa class.
The U.S.S. Arizona was a Pennsylvania class, commissioned in 1916.
Never heard of any U.S. Battleships having 18'' main guns, 16'' is the largest I can reference to.