 The twelve 45 @-@ calibre 35 @.@ 6 cm ( 14 @.@ 0 in ) Type 41 guns of the Ise class were mounted in three pairs of twin @-@ gun , superfiring turrets . Numbered one through six from front to rear , each turret weighed 655 long tons ( 666 t ) . The hydraulically powered turrets had an elevation capability of − 5 / + 20 degrees . The guns had a rate of fire of 1 @.@ 5 – 2 rounds per minute and could be loaded at any angle between -3 and + 20 degrees . In 1921 the elevation was increased to + 30 degrees and then to + 43 degrees during their mid @-@ 1930s modernization , except for No. 6 turret as its supporting structure could not be lowered . The recoil mechanism of the guns was also changed from a hydraulic to a pneumatic system , which allowed for a faster firing cycle of the main guns . 
