Key Points and Summary – IJN Musashi—sister ship to Yamato—was among the largest, most heavily armed battleships ever built.
-Laid down in Nagasaki and launched in November 1940, Musashi carried nine 18.1-inch Type 94 guns and a massive secondary battery.
-Commissioned in 1942 and briefly serving as Combined Fleet flagship, she saw limited action as carriers reshaped Pacific warfare.
-After a March 1944 torpedoing by USS Tunny, Musashi returned to service—only to be sunk on 24 October 1944 in the Sibuyan Sea under waves of U.S. carrier-borne bombers and torpedo planes.
-In 2015, a team funded by Microsoft cofounder Paul Allen located the wreck at ~1,000 meters depth, confirming the fate of the Imperial Navy’s engineering pinnacle.
Musashi: One of the Biggest Battleships Ever
The Musashi was a giant Japanese battleship. It was ordered in the late 1930s and built in the early 1940s, after World War II had already started.
The ship was launched in November 1940, about a year before Pearl Harbor.
According to Naval History and Heritage Command, the Musashi was built in Nagasaki. It would be the last ship built there by the Imperial Japanese Navy, and it was commissioned in 1942. The ship was 862 feet long and had a crew of 2,399 sailors. It was struck by American torpedoes in March of 1944 and returned to service that summer. But that October, the Musashi was struck and ultimately sunk.
The Building of the Ship
According to Naval Historia, the Musashi was “one of the largest and most heavily armed battleships ever constructed.”
“The design and construction of the Japanese battleship Musashi were monumental undertakings that pushed the boundaries of naval architecture and engineering of the time,” Naval Historia reports. “Musashi, alongside her sister ship Yamato, was conceived in the context of an escalating arms race leading up to World War II.”
Yamato-Class Battleships Musashi and Yamato. Image Credit: Creative Commons.
Naval Historia added that Japan built the ship to “counter the naval capabilities of potential adversaries,” including the United States, and that it was developed in secret, with a stringent effort to avoid intelligence leaks. Indeed, the U.S. was unaware of the ship’s existence while it was being constructed.
“Musashi’s design was a masterpiece of naval engineering, embodying the zenith of battleship technology,” Naval Historia said. It was built to carry “the largest guns ever mounted on a warship, while also providing enough armor to protect against similar weapons.”
Big Guns
Per Naval Historia, the centerpiece of the ship design was “her main battery of nine 46-cm (18.1-inch) Type 94 naval guns, the largest caliber guns ever fitted to a warship.” The secondary armament also included a complement of 155-mm guns.
In 1943, Admiral Isoroku Yamamoto, commander of the Combined Fleet, named Musashi the fleet’s flagship. Just a few months later, Yamamoto, seen as the mastermind of Pearl Harbor, would be killed during Operation Vengeance.
The Naval Historia account went on to note that for all its prowess, the Musashi’s “opportunities to engage in the kind of decisive naval gun battles for which she was designed were limited by the nature of the Pacific War,” when aircraft carriers became more important.
The Musashi ended up playing a “peripheral” role in the Battle of the Philippine Sea in June 1944.
“The military history of Musashi is practically non-existent,” War History Online wrote. “Musashi then spent her short life transporting troops and supplies, or discharging her anti-aircraft artillery against Truk, an atoll of the Caroline Islands.”
In March 1944, the Musashi was struck by six torpedoes from the American submarine USS Tunny, with one striking the bow.
The Day the Musashi Sank
The battleship would reach its end during the Battle of Leyte Gulf in June 1944.
As War History Online recalls, it all went down on Oct. 24, 1944.
“Musashi was attacked by approximately 259 aircraft launched in 6 waves from the aircraft carriers USS Intrepid, USS Essex, USS Franklin, and USS Enterprise. The attacking aircraft were Curtiss SB2C ‘Helldiver’ bombers and Grumman TBF ‘Avenger’ torpedo bombers.”
The ship was hit hard, receiving a total of “19 torpedo hits, 10 to its port and 9 to its starboard side, 17 bomb impacts, as well as suffering from 18 near-misses on the water near its hull.”
The battleship’s commander, Admiral Inoguchi, attempted to steer the Musashi to an island, but the ship sank before he could. Per War History Online, 1,376 survivors were rescued out of the crew of 2,399 men.
Japan Reflects
In October 2024, the U.S. Naval Institute wrote about Japanese reflections on that decisive Leyte Gulf battle – that month was the battle’s 80th anniversary.
“In the areas close to where the attacks occurred, the electricity flickered and sometimes went out completely,” Hayakawa, who was aboard the ship, said, according to USNI. “The sound and impact were very strong and reverberated throughout the ship.”
“When it came to Musashi’s brave fight, I was able to see it with my own eyes and it still stays in my mind,” a man named Tsuchiya said.
Finding the Wreckage
More than 71 years after it sank, the wreckage of the Musashi was found.
Microsoft cofounder Paul Allen funded an exploration team to find the wreckage. Allen has said he carried out the mission “because, since my youth, I have been fascinated with Second World War history.” The mission utilized The Octopus, Allen’s yacht, as well as an additional Remote Operated Vehicle.
The mission was not easy; the exact location of the wreckage wasn’t entirely clear. The search therefore included a hypsometric bathymetric survey of the ocean floor, which helped rule out some locations in the search. But the explorers found it.
“The Musashi is truly an engineering marvel, and, as an engineer at heart, I have a deep appreciation for the technology and effort that went into its construction,” Allen said at the time, per the Seattle Post-Intelligencer.
The vessel “was at a depth of more than 1km (3,280ft) on the floor of the Sibuyan Sea off the Philippines,” the BBC reported. The discovery came at the end of an eight-year effort and utilized an Autonomous Underwater Vehicle to discover the battleship in the Philippine archipelago.
The expedition also uncovered a “ghostly underwater photograph of the mammoth vessel’s rusting, coral-encrusted bow clearly bearing the chrysanthemum crest of the Japanese imperial family.”
Japan has a museum, located in Hiroshima, dedicated to the Yamato, the Musashi’s sister ship. The head of that museum told the Seattle newspaper that the shipwreck discovered in 2015 “must be the Musashi.”
About the Author: Stephen Silver
Stephen Silver is an award-winning journalist, essayist, and film critic, and contributor to the Philadelphia Inquirer, the Jewish Telegraphic Agency, Broad Street Review, and Splice Today. The co-founder of the Philadelphia Film Critics Circle, Stephen lives in suburban Philadelphia with his wife and two sons. For over a decade, Stephen has authored thousands of articles that focus on politics, national security, technology, and the economy. Follow him on X (formerly Twitter) at @StephenSilver, and subscribe to his Substack newsletter.
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