 A special Type 3 "Sankaidan" incendiary shrapnel shell was developed in the 1930s for anti-aircraft use.As built, the "Fusō" class was fitted with a secondary armament of sixteen 50-caliber six-inch guns mounted in single casemates along the sides of the hull at the level of the upper deck.Eight guns were mounted per side, and each had an arc of fire of 130 degrees and a maximum elevation of +15 degrees.