IJN Musashi

Musashi was the second of the Yamato-class giants — the answer Japan built to a problem it could not solve any other way. Unable to match American shipyards ship for ship, the Imperial Japanese Navy gambled on individual supremacy: battleships so large and so heavily gunned that each could, in theory, fight several enemies at once. Two were completed to the design; the third hull was finished as the carrier Shinano.

She was laid down on 29 March 1938 at the Mitsubishi yard in Nagasaki — a commercial yard in a working city, where concealment was far harder than at the naval arsenal that built Yamato. Enormous rope screens were hung around the slipway and the surrounding hillsides were screened from view. She was launched on 1 November 1940 in a ceremony kept deliberately small for a hull of her size, and commissioned on 5 August 1942.

Musashi shared her sister’s scale: 263 m overall, a beam of 38.9 m, and over 72,000 tons at full load — the largest battleships ever built. Her nine 460 mm (18.1-inch) guns were the heaviest naval artillery ever mounted afloat, and the figure that makes that more than a superlative is the shell: 1,460 kg against the 1,225 kg of the American 16-inch/50 that armed the Iowa class. Each turret weighed more than a destroyer.

Her protection was built to the same standard — a main belt up to 410 mm, turret faces of 650 mm, deck armour of 200–230 mm — and was calculated against the heaviest shellfire at battle range. Four steam turbines and twelve boilers gave ~150,000 shp for 27 knots, slower than the fast American battleships she was meant to out-shoot but fast enough to work with the fleet.

What the design could not answer was the aeroplane, and the gap was not a matter of quantity. By 1944 Musashi carried well over a hundred 25 mm Type 96 automatic cannon, but the weapon was poor for the task: a cyclic rate of ~220 rounds a minute that fell far lower in practice, because it fed from 15-round magazines and stopped to reload every few seconds; triple mounts that were hand-trained, too slow to follow a diving aircraft; and an effective reach against aircraft of roughly 1.5–3 km against the ~9 km ceiling of her 127 mm dual-purpose guns.

That left a layered defence with the wrong layer doing the work. The 127 mm battery was the weapon with the reach, and the 25 mm barrels could only engage aircraft already inside their attack runs. As completed she carried twelve 127 mm guns to cover a hull 263 m long; the 1944 refit doubled that number, and it was still twenty-four long-range barrels against carrier strikes arriving in waves.

For most of her career Musashi did what Yamato did: she waited. The two giants spent long months at the Truk anchorage, held back as a strategic reserve for the decisive fleet action that Japanese doctrine still expected. Fuel shortages and the sheer value placed on them kept the heaviest guns in the navy idle while the carrier war was lost around them.

In February 1943 she relieved Yamato as flagship of the Combined Fleet. In May that year she carried the ashes of Admiral Isoroku Yamamoto home from Truk, reaching Tokyo Bay on 23 May 1943. In the two years between her commissioning and the Philippines she did not fire her main battery at an enemy ship once.

Her first damage came from below. On 29 March 1944, leaving Palau, she was hit forward by a torpedo from the submarine USS Tunny. One hit on a ship of her size was not dangerous in itself — she took on water forward and made Japan under her own power — but it put her in the yard at a moment when the navy had decided what its battleships were now for.

The refit that followed at Kure was an admission. Her wing 155 mm secondary turrets were landed to make room for anti-aircraft guns: the 127 mm battery was doubled from twelve barrels to twenty-four, and the 25 mm fit grew to around 130. She left Kure with roughly six times as many light anti-aircraft barrels as heavy ones.

On 24 October 1944, steaming with the Centre Force toward Leyte Gulf, Musashi entered the Sibuyan Sea and the concentrated attention of Admiral Halsey’s carrier aircraft. Helldivers and Avengers from the US Third Fleet came in waves through the morning and afternoon and singled her out: she was the largest target in the formation, and as she began trailing oil and losing speed she became the easiest to find. By mid-afternoon she had fallen behind the force she was meant to be screening.

What killed her was not any single hit but the water. Torpedo damage forward opened her to progressive flooding that outran the damage-control parties; she went down by the bow until her forecastle was awash, and counter-flooding to correct the list cost her the reserve buoyancy she needed.

The American tally for the day is around 17 bombs and 19 torpedoes, and this entry states it as what it is: a US estimate assembled from attacking aircrews’ claims across many separate waves. Japanese survivor and damage-report accounts give lower totals, the two cannot be reconciled because the ship took most of her records down with her, and no supportable alternative total is available.

She capsized to port and sank in the evening of 24 October. Rear Admiral Toshihira Inoguchi chose to remain aboard and went down with the ship. Losses are commonly cited as ~1,023 of a complement of roughly 2,400, and no supportable alternative figure is available: the complement itself was not fixed — the 1944 refit added large numbers of anti-aircraft crew — the survivors were taken off by several destroyers with separate tallies, and accounts differ on whether men landed in the Philippines and killed in the fighting there are counted against the ship.

The Centre Force’s objective was Leyte Gulf, and what it did is documented: the rest of the force passed through the San Bernardino Strait that night and fell on the escort carriers off Samar the next morning, where the destroyer USS Johnston and her sisters made their stand. It is a common interpretation — not an established fact — that the air effort spent on Musashi through 24 October is what left the strait open, since the same strikes could not be in two places at once. Leyte Gulf was a catastrophe for Japan either way.

The verdict on the class is a fact rather than an opinion: Yamato and Musashi were the largest, most heavily gunned and most expensive battleships ever built, and between them they sank no enemy capital ship. Musashi’s 460 mm guns, designed to smash an American battle line, never fired at one. Yamato followed her in April 1945, sunk by aircraft in the same way.

The wreck lay unfound for seventy years. In March 2015 a research team funded by Paul Allen located Musashi more than 1,000 m down in the Sibuyan Sea, identifying her from a chrysanthemum bow crest, a main-gun turret and a valve wheel stamped with the Mitsubishi mark.

She lies inverted and broken, and is a war grave: over a thousand of her crew are still aboard. The Japanese government has asked that the site be treated accordingly, and no recovery of material has been authorised.

• Janusz Skulski, The Battleship Yamato (Anatomy of the Ship, Conway) — covers the Yamato class.
• William H. Garzke & Robert O. Dulin, Battleships: Axis and Neutral Battleships in World War II (Naval Institute Press).
• Thomas J. Cutler, The Battle of Leyte Gulf, 23–26 October 1944 (Naval Institute Press).