 The ships ' secondary armament consisted of twenty 50 @-@ calibre 14 @-@ centimetre Type 3 . Eighteen of these were mounted in casemates in the forecastle and superstructure and the remaining pair were mounted on the deck above them and protected by gun shields . They had a maximum elevation of + 20 degrees which gave them ranges of 16 @,@ 300 metres ( 17 @,@ 800 yd ) . Each gun had a rate of fire of up to 10 rounds per minute . Anti @-@ aircraft defence was provided by four 40 @-@ calibre 3rd Year Type 8 @-@ centimetre AA guns in single mounts . The 7 @.@ 62 @-@ centimetre ( 3 in ) high @-@ angle guns had a maximum elevation of + 75 degrees , and had a rate of fire of 13 to 20 rounds per minute . They fired a 6 kg ( 13 lb ) projectile with a muzzle velocity of 680 m / s ( 2 @,@ 200 ft / s ) to a maximum height of 7 @,@ 500 metres ( 24 @,@ 600 ft ) . The ships were also fitted with six submerged 53 @.@ 3 @-@ centimetre ( 21 @.@ 0 in ) torpedo tubes , three on each broadside . They carried twelve to eighteen 6th Year Type torpedoes which had a 200 @-@ kilogram ( 440 lb ) warhead . They had three settings for range and speed : 15 @,@ 000 metres ( 16 @,@ 000 yd ) at 26 knots ( 48 km / h ; 30 mph ) , 10 @,@ 000 metres ( 11 @,@ 000 yd ) at 32 knots ( 59 km / h ; 37 mph ) , or 7 @,@ 000 metres ( 7 @,@ 700 yd ) at 37 knots ( 69 km / h ; 43 mph ) . 
