 The 6 pairs (3 per side) of fixed torpedo tubes mounted on the middle deck were replaced with 2 quadruple mounts using the powerful Type 93 torpedo, located on the upper deck, one on each side of the catapult.The bridge structure was rebuilt almost identically to the "Furutaka" class modifications to accommodate the latest rangefinders and fire control equipment for the main battery, antiaircraft and torpedoes.Of the twelve original boilers, two smaller ones were mixed-fuel capable.