Golden Journal No. 42:
Battleship-Carriers
Publisher’s Preview
by Mike Bennighof, Ph.D.
April 2022

By early 1942, naval staffs in the United States and Japan had seen hard proof that the aircraft carrier would be the decisive weapon of the Pacific naval war, not the battleship. In both countries, naval architects conducted a rapid survey of large warships suitable for conversion to aircraft carriers.

In the United States, the panic came immediately after Pearl Harbor. Initially the emergency carrier proposal centered on eight large hulls: the six fast battleships of the Iowa class, and the first two battle cruisers (“large cruisers” in U.S. Navy parlance) of the Alaska class. Five Iowa class ships had been laid down at that point, but none had yet been launched; laying down of the sixth unit was delayed pending a decision on whether to complete her as a carrier or a battleship.

While six Alaska-class large cruisers had been ordered under the September 1940 Two-Ocean Navy Act, only two had been laid down by the spring of 1942; a third would follow in December 1943 and the last three would be cancelled outright. Smaller warships – Baltimore-class heavy cruisers and Cleveland-class light cruisers - could be turned into light carriers with limited air groups, but only the eight battleship or large cruiser hulls could become full-sized fleet carriers.

Once things settled somewhat, cooler heads found a few problems with the proposed fleet carrier conversions. They would take much longer to complete than would new Essex-class carriers built from the keel up, absorbing considerably more cash, steel and labor as well. Once complete, they would not be as effective as the purpose-built ships: they would carry fewer aircraft than an Essex-class ship, with a shorter steaming range, and though they would be better-protected against enemy shellfire this was a relative thing, as they would not be armored against battleship guns any more while their internal subdivision (and thus their resistance to torpedoes) would be less effective than that of the Essex class.

And so the battleships and battle cruisers would be completed as battleships and battle cruisers (well, four of the six battleships, anyway) while two more Essex-class ships were ordered in December 1941 to join the 11 already on order, with ten more ordered in August 1942 and a further three in June 1943. Of those 26 orders, only one would be cancelled before completion.

Panic gripped the Japanese some months later, when four fleet carriers (out of a total inventory of six) went to the bottom of the Pacific Ocean west of Midway Island. With only one new fleet carrier under construction, this presented a serious problem. Like the Americans six months earlier, the Japanese naval staff cast their eyes on ships under construction that might be converted into aircraft carriers. Unlike the Americans, they found very few candidates: the third battleship of the Yamato class and the two heavy cruisers of the Ibuki class.

Shinano and the first heavy cruiser, Ibuki, would be converted into carriers. Work on the second cruiser, which never received a name, had been laid down just a few weeks before, was suspended as it seemed better to start over with a purpose-built aircraft carrier on the same slipway.

With so few heavy ships under construction, the discussion moved to those ships already in service. Perhaps the four battle cruisers of the Kongo class could be used, or the four older battleships of the Fuso and Ise classes, or the two newer dreadnoughts of the Nagato class. Or all ten of them.

Each grouping presented problems: the battle cruisers were considered vital to protect carrier task forces from surface attack. If they became aircraft carriers themselves, then the carrier escort groups would lose considerable firepower. The four older dreadnoughts were older, slower and lacked modern underwater protection. The two newest dreadnoughts had 16-inch guns the admirals were loathe to send ashore.

Ultimately the Japanese reached the same conclusion as the Americans: purpose-built carriers could enter service faster than converted battleships and battle cruisers, and do it more cost-effectively. The Imperial Navy placed emergency orders for sixteen (!) fleet carriers of the Unryu class, a simplified variant of the carrier Hiryu lost at Midway. Three of them would be completed, with one actually surviving the war.

Instead of razing the old dreadnoughts to their main deck and converting them to through-deck carriers, they would become hybrid battleship-carriers operating a large group of seaplanes.  Two of them would actually undergo conversion, Ise and Hyuga. The two older ships had a slightly different layout that would require sacrificing three of their six turrets rather than just two for the Ise class ships (plus, Hyuga had already lost one turret to an ammunition explosion, making the decision easier). That would entail more work and expense, while reducing their surface firepower.

We’ve got all of these proposed conversions in Golden Journal No. 42: Battleship-Carriers. The Americans get all eight converted carriers: all six Iowa-class fast battleships and the pair of battle cruisers. Yes, the battleship Illinois wasn’t even laid down until after the conversion plan had been rendered moot and so was even more unlikely to have been made into an aircraft carrier, but you need a piece for her.

The American drawings are based on the actual American conversion plans, which in turn were very heavily based on the Essex class aircraft carriers (at least the above-the-waterline parts of the ships). They’re a little shorter and thicker than Essex, with the ex-battle cruisers even shorter, with the same island design and deck armament.

The Japanese get all ten of their heavy ships in aircraft carrier guise: the four older dreadnoughts, the two newer dreadnoughts, and the four battle cruisers. No actual drawings of these proposals seem to have survived the war, so our drawings are based on the final reconstruction of the battleship Kaga as an aircraft carrier, at least outwardly. In terms of their inner structure, it’s probably a safe assumption that they would have come closer to more recent Japanese practice – which, while not as good as American designs, was still better than Kaga. The converted battle cruisers are, of course, a modified version of the former battle cruiser Akagi.

This being a Golden Journal, we of course tell you all about the converted ships, and give you scenarios (for Midway Deluxe Edition) so you can play with them. Every Ship Guy needs this Journal: twenty new pieces, die-cut and silky smooth, with that extraordinary ship artwork you love.

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Mike Bennighof is president of Avalanche Press and holds a doctorate in history from Emory University. A Fulbright Scholar and NASA Journalist in Space finalist, he has published a great many books, games and articles on historical subjects; people are saying that some of them are actually good. He lives in Birmingham, Alabama with his wife, three children, and his Iron Dog, Leopold.

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