Her main armament consisted of six BL 9 @.@ 2 @-@ inch Mk X guns in single turrets , two on the centreline and two on each beam , giving a broadside of four 9 @.@ 2 in guns . Her secondary armament of four BL 6 @-@ inch Mark XI guns was arranged in single casemates . They was mounted amidships on the main deck and was only usable in calm weather . Twenty Vickers QF 3 @-@ pounders was fitted , six on turret roofs and fourteen in the superstructure . The ship also mounted three submerged 18 @-@ inch torpedo tubes .