The Ships of Battlegroup: Japan Mutsu (BB)

Displacement	39,050 tons	Belt Armor	13 inches
Overall Length	738 feet	Deck Armor	3.5 inces
Beam	113 feet	Main Turret Armor	14 inches
Speed	25 knots	Main Guns	8 × 16″

Laid down on June 1, 1918, launched on May 31, 1920 and commissioned on October 24, 1921, the ship carried a main armament of eight of the new 16 inch main guns mounted two per turret; two superfiring centerline forward and two superfiring centerline aft. Mutsu was the second ship of the two-ship Nagato battleship class and the ships had a mixture of 15 oil-fired and six mixed-firing boilers that gave them the exceptional speed of 26.7 knots. At the time of their construction, these were the most powerful battleships in the world—they had bigger guns, were better protected and faster than the excellent British Queen Elizabeth class and they were in the water before the similarly-armed and much slower American Colorado class. “Mutsu” is the name of an area in Japan.

The Japanese were always worried about the superior number of United States battleships and were always trying to put superior ships into the water, which was the case when the Nagato and Mutsu were launched. Restricted in battleship tonnage by treaty and unable to afford much new construction, the Japanese poured great efforts into modernizing and updating their battleline during the 1930s. In 1934, both ships of the class started major reconstruction that added bulges for added underwater protection (increasing beam from 95 to 113 feet), added a triple bottom, installed new oil-fired boilers and new engines that enabled them to steam at 25 knots, even with the broader beam, added the distinctively ugly Japanese “pagoda” foremast, replaced the guns with newer models with a higher angle of fire and longer range and increased the antiaircraft protection. In addition to modernization, the Japanese Imperial Navy honed a much superior surface night fighting capability with exhaustive training and equipped their cruisers and destroyers with the devastating “Long Lance” torpedo. Mutsu sortied and took part in the attempted Midway invasion in mid 1942 and was distantly involved in some of the later operations around Guadalcanal. On June 8, 1943, one of her magazines exploded while anchored in Hashirajima Bay and she was lost in this cataclysmic accident.

For other pre-World War Two battleships with 16 inch guns, see: Maryland and Nelson.

For a Queen Elizabeth class battleship, see: Warspite.

For a further discussion of what happened to the battleships of World War One, see the Introduction to these articles.