 They were initially fitted with a Type 13 fire @-@ control system derived from Vickers equipment received during World War I , but this was replaced by an improved Type 14 system around 1925 . It controlled the main and secondary guns ; no provision was made for anti @-@ aircraft fire until the Type 31 fire @-@ control director was introduced in 1932 . A modified Type 14 fire @-@ control system was tested aboard Nagato in 1935 , and later approved for service as the Type 34 . A new anti @-@ aircraft director , designated the Type 94 , used to control the 127 mm AA guns , was introduced in 1937 , although it is unknown when they were installed on the ships . The 25 mm AA guns were controlled by a Type 95 director that was also introduced in 1937 . 
