The Dreadnought was built by Britain and it was revolutionary in another sense. It was the first battleship to mount all its main guns in rotating turrets rather than below deck casements, thus allowing all of her main guns to bear on a target in virtually any direction. In addition, she was the first battleship to have the same calibre of main armament. (10x12 inch guns if I don't have a memory cramp) Before that, the casement mounted guns could only be brought to bear on one quarter of the compass. (i.e. A battery could only fire on targets bearing 0 to 90 degrees, C battery from 90 to 180. etc.) It was impossible for all the guns to engage one target, and because of this, it was relatively easy to predict which way a ship would turn to unmask the next set of guns. Some preceding warships did have turrets, but usually they only had 2 or 4 main guns. The dreadnought had no such weakness, she could fire in one direction and manouvre in any other, and in addition, the casement batteries were a major weakness in terms of armour thickness and water entry in heavy seas. The Dreadnought did not need them.
Dean.