Technically speaking, these are two different classes, but they were practcially identical. I used to kind of scoff at these cruisers, because by the time WWII rolled around their main armament was hopelessly wimpy (6 x 8" guns, compared to 10 x 8" on the Myoko and Takao classes, and 9 x 8" on most U.S. CAs). On the other hand, they were apparently handy seaboats, well thought of by their sailors, and remarkably durable. From a naval architectural standpoint, they are intriguing because they represent the first attempt on the part of the Japanese to economize on weight by using the vessel's armor plating as part of the actual structure. Other indications of this effort to economize on weight include the sloping of the stern aft of Turret #3, a feature which became common in many Japanese naval vessels thereafter, and whose ultimate extension can be seen in the sloping main deck of Yamato forward of Turret #1 (and I always thought they did it because they knew how cool it looked.)
Year Completed Furutaka: 1926
Kako: 1926
Aoba: 1926
Kinugasa: 1926
Displacement Furutaka-class:10,507 tons
Aoba-class: 10,822 tons
Dimensions 595'0" x 51'9" (Aoba-class: 57'9") x 18'3" (Aoba-class: 18'7")
Speed 33 knots
Armament 6 x 8"/50
4 x 4.7"/45 DP
up to 42 x 25mm AA
8 x 24" TT
Crew 625
