The progress of Fusō 's construction , while the IJN waited for the funding to be released and foreign developments , caused the IJN to reassess the Fusō @-@ class design . The distribution of the midships gun turrets was the most obvious flaw as they complicated the protection of the midships magazine and exposed more of the ship to the blast effects of the guns when they fired . Another issue was that Japanese sailors had problems maintaining a high rate of fire with the 45 @.@ 36 @-@ kilogram ( 100 @.@ 0 lb ) shells used in the manually loaded 152 @-@ millimetre ( 6 in ) secondary guns used in the Fusō class and earlier designs . To resolve this issue , the IJN designed a smaller 140 @-@ millimetre ( 5 @.@ 5 in ) gun that offset its lighter shell weight with a higher rate of fire . It also decided that the barbette armour of the earlier ships was too thin and wanted a modest increase in speed to partially counter the higher speeds of the latest foreign ships like the British Queen Elizabeth @-@ class battleships and Russian Borodino @-@ class battlecruisers . For financial reasons more powerful engines could not be ordered so the new design was lengthened slightly and the boiler rooms enlarged to increase speed by 0 @.@ 5 knots ( 0 @.@ 93 km / h ; 0 @.@ 58 mph ) to 23 knots ( 43 km / h ; 26 mph ) . To save weight the forecastle deck was shortened so that the lower midships gun turret was lower than in the Fusō class . This reduced the crew 's accommodations despite a significant increase in the crew 's numbers and naval historian Fukui Shizuo believed that these ships had the worst habitability of any Japanese capital ship . The final design was designated A @-@ 92 by the IJN and differed enough from the A @-@ 64 design of the Fusō class that it was considered a separate class .