Armour: The Fuso, when built, had an armour displacement of 8,588 tonnes, roughly 29% of the ships weight, between 1930 and 1933 this was increased to 12,199 tonnes with extra horizontal protection and torpedo blisters from the top of the belt down to the bottom of the hull. Engines: When built, the Fuso class employed a mixture of coal/oil boilers (24 of them) to propel the ship at 23 knots. When modernised in the early 30s these boilers were replaced with Kanpon Oil-fired burners increasing the total speed to almost 25 knots.