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Britain
is it the HMS Dreadnought
HMS Dreadnought used the following:10 x 12" (305mm) main, 24 x 12 pounder(76mm) and 5 x 18" torpedo tubes.
None.
HMS Dreadnought only sank one enemy ship, and that was a U-boat, which it sank by ramming.
A dreadnought is a modern all-big-gun (12" guns or larger) battleship. Named for HMS Dreadnought, launched in 1905.