Japanese battleship Mutsu

Japanese battleship Mutsu was a Nagato-class battleship of the Imperial Japanese Navy (IJN), the second and last ship of her class. Named after Mutsu Province, she was commissioned in 1921 and was one of the most powerful capital ships in the world during the interwar period. Her career was marked by modernization, participation in major Pacific War operations, and a catastrophic internal explosion in 1944 that destroyed the vessel.

Design and description

The design of the *Nagato*-class represented a significant leap forward for Japanese naval engineering, intended to rival new American Standard-type battleships like the USS *Colorado*. As built, *Mutsu* displaced 33,800 long tons and was powered by four Gihon turbines driving four propellers, capable of a top speed of 26.5 knots. Her primary armament consisted of eight 41 cm (16.1 in) 45-caliber guns mounted in four twin turrets, making her and her sister ship *Nagato* the first battleships in the world to carry guns of this caliber. Secondary armament included twenty 14 cm/50 3rd Year Type naval guns and an anti-aircraft battery of four 7.6 cm (3 in) guns. Her armor protection utilized a sophisticated "all or nothing" scheme, with a main belt of Vickers hardened steel up to 305 mm (12 in) thick. During a major reconstruction from 1934 to 1936 at the Kure Naval Arsenal, her hull was lengthened, anti-torpedo bulges were added, and her machinery was completely replaced, increasing her displacement to over 39,000 long tons. Her superstructure was rebuilt into a distinctive pagoda mast, and her anti-aircraft armament was significantly enhanced with additional 25 mm autocannons.

Construction and career

*Mutsu* was laid down at the Yokosuka Naval Arsenal on 1 June 1918, launched on 31 May 1920, and commissioned on 24 October 1921. She served as the flagship of the Combined Fleet on multiple occasions and participated in numerous fleet reviews and exercises during the interwar years. Following the outbreak of the Pacific War, she was part of the distant covering force for the Attack on Pearl Harbor in December 1941. In 1942, she was part of the main body of the Combined Fleet during the Battle of Midway and later participated in the Battle of the Eastern Solomons and the Battle of the Santa Cruz Islands, though she saw no direct surface combat. For much of 1943, due to fuel shortages and strategic priorities, she remained largely inactive in the Inland Sea, used primarily for training and as a symbol of Japanese naval power. Her final major operation was the transport of troops and supplies to Wake Island in late 1943.

Loss

On 8 June 1944, while anchored in Hashirajima anchorage near Hiroshima, *Mutsu* was destroyed by a massive internal explosion in her Number 3 turret magazine at approximately 12:13 PM. The ship broke in two and sank quickly, with the loss of 1,121 officers and crewmen, including the commander of the Battleship Division 1, Rear Admiral Miyoshi Teruhiko. A total of 353 survivors were rescued. An immediate investigation by the Imperial Japanese Navy concluded the explosion was likely caused by the deliberate act of a disgruntled crewman, though other theories, including defective *sanshiki-dan* (anti-aircraft) shells or accidental ignition, were also considered. The official cause remains a subject of historical debate.

Wreck

The wreck of *Mutsu* lies in approximately 40 meters (130 ft) of water in Hiroshima Bay. The bow and stern sections are separated, with the stern resting upside down. In the 1970s, salvage operations were conducted by a private company to recover valuable materials, including her valuable Vickers-manufactured armor plate and approximately 580 of her 16-inch shells. Her salvaged mainmast was relocated and is now displayed as a memorial at the Yasukuni Shrine in Tokyo, while one of her 15.5 cm secondary gun turrets is preserved at the Museum of Maritime Science.

Legacy

*Mutsu* remains a significant subject in Japanese naval history, symbolizing both the technological prowess of the IJN and the tragic, sudden losses it suffered. Her sister ship, *Nagato*, survived the war only to be used as a target ship in Operation Crossroads at Bikini Atoll. The story of *Mutsu*'s loss is frequently examined in historical studies of the Pacific War and is a notable example of a non-combat capital ship loss. The recovered artifacts serve as tangible memorials, and the circumstances of her sinking continue to be analyzed by historians and naval enthusiasts.

Category:Battleships of the Imperial Japanese Navy Category:Nagato-class battleships Category:World War II battleships of Japan Category:Ships built in Yokosuka, Kanagawa Category:Maritime incidents in 1944