Originally built as light cruisers with fifteen 6.1" guns, they were modified to heavy cruiser configuration just before the war began.
Mikuma and Mogami received principal credit for destroying USS Houston and HMAS Perth in the Battle of Sunda Strait, night of Feb/Mar42. They also accidentally torpedoed and sank 4 of their own troop-laden transports and an escort ship, although that was blamed on the Japanese destroyer Fubuki for some years.
In June 1942, their class was escorting the invasion ships for the Battle (and invasion) of Midway (Island), but were called back after the loss of all four first-line aircraft carriers of the Kido Butai strike group. Nonetheless, they were repeatedly attacked by American aircraft. Mikuma was eventually sunk, and Mogami slinked away with her stern and its gun turrets utterly wrecked, to the point that it was decided to install a flight deck there instead -- making it a class of its own -- as was being done for battleships Hyuga and Isa.
The last three ships of the class were all in the Battle of Leyte Gulf. Mogami was finally sunk in the south, after the Battle of Surigao Strait. None of them s survived the war.
A 1:1800 "2-D model" of the class is below the ONI drawing.
Now would you like to return to my home page or the main drawings page?