The Buzz

The Ultimate Battleship Battle: Japan's Yamato vs. America's Iowa

It would have been the ultimate duel of dreadnoughts. In one corner, Japan’s Yamato, weighing in at 65,000 tons, the biggest battleship in history. In the other corner, Iowa, at 45,000 tons the pride of America's World War II battleship fleet. In reality, the two ships never met in battle. But what if they had, in a cataclysmic clash of seagoing titans?

One researcher can offer an answer, or at least a very educated guess. Jon Parshall, historian and author of the superb Shattered Sword: The Untold Story of the Battle of Midway has pitted the top battleships of various nations against each other at Combinedfleet.com, the go-to site for information on the Imperial Japanese Navy.

Among the battleships he compares are Yamato and Iowa, based on five criteria: guns, armor, underwater protection, fire control and “tactical factors” such as speed and damage control.

It would have been the ultimate duel of dreadnoughts. In one corner, Japan’s Yamato, weighing in at 65,000 tons, the biggest battleship in history. In the other corner, Iowa, at 45,000 tons the pride of America's World War II battleship fleet. In reality, the two ships never met in battle. But what if they had, in a cataclysmic clash of seagoing titans?

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One researcher can offer an answer, or at least a very educated guess. Jon Parshall, historian and author of the superb Shattered Sword: The Untold Story of the Battle of Midway has pitted the top battleships of various nations against each other at Combinedfleet.com, the go-to site for information on the Imperial Japanese Navy.

Among the battleships he compares are Yamato and Iowa, based on five criteria: guns, armor, underwater protection, fire control and “tactical factors” such as speed and damage control.

Guns:

Yamato’s 18.1-inch guns were the largest ever mounted on a warship. Since they couldn't match American quantity, it was Japanese navy doctrine for each warship to be more powerful than its individual U.S. counterpart. Yamato’s nine 18-inchers could throw a 3,200-pound shell out to 26 miles, while Iowa’s nine 16-inch guns could propel a 2,700-pound shell 24 miles.

Even though Japanese shells were less effective than American ones, the range advantage should belong to Yamato. Yet the real issue was even hitting the target in the first place. Given World War II fire control systems, the chance of hitting a battleship moving at 30 miles per hour from a distance of 25 miles is very small.

For his analysis, Parshall assumes that both battleship captains would close the range to less than 23 miles. At that distance, both the Yamato’s and Iowa’s guns could penetrate each other’s armor. “That’s why I say there’s a lot of luck involved here,” Parshall explained. “Iowa’s fire control is better. But if Yamato gets lucky and gets in the first hit or two, and they’re doozies, it could very easily be game over for Iowa.”

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Advantage: neither ship.

Armor:

Yamato seemingly had the edge here, with 16 inches of belt armor to Iowa’s 12 inches. The Japanese vessel had 9 inches of deck armor to Iowa’s 6, and an impressive 26 inches of armor on the faces of her main gun turrets, versus just 20 inches of turret armor for Iowa.

“Yamato was simply built to stand up to and utterly outclass any conceivable American or British opponent by sheer weight of gunfire and elephant-like armor,” Parshall writes. “As such, hers is a sort of ‘brute force’ approach to protection. Her armor layout isn’t the most efficient, but she has a lot of armor, so it doesn’t really matter.”

While Yamato was thickly armored everywhere, Iowa’s armor was thicker over her more vital areas. However, as Parshall points out, only America could afford to build battleships with hulls and interiors constructed entirely out of tough but light Special Treatment Steel, which meant that U.S. battleships could be smaller and lighter for an equivalent amount of protection.

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Nonetheless, Parshall gives a slight edge to Yamato here; if both ships suffered damage to their fire control systems and had to close the range, the invulnerability of Yamato’s turrets to Iowa’s shells could prove important.

Advantage: Yamato.

Underwater Protection:

Why is a battleships’s underwater armor important? Battlewagons hurled big cannon shells at each other, not torpedoes, which is why battleships tended to be more heavily armored above the waterline.

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