 The anti @-@ aircraft armament was intended to be four 38 @-@ caliber 64 @-@ millimetre ( 2 @.@ 5 in ) anti @-@ aircraft guns fitted on the upper deck with 220 rounds stored per gun . Four 75 @-@ millimetre ( 3 @.@ 0 in ) guns were to be mounted in pairs on the main turret roofs for sub @-@ caliber training with the main guns . Six underwater 450 @-@ millimetre ( 18 in ) torpedo tubes were fitted , three on each broadside ; they were provided with a total of eighteen torpedoes . 
