History enthusiasts have long wondered how a fight would have turned out between two of the most famous battleships of World War 2: the Japanese Yamato and U.S.S. Iowa. At 69,646 tons, the Yamato was the largest battleship ever built and boasted the largest naval guns ever built. The 48,500 ton American Iowa-class battleships were faster than the Yamato but were less heavily armored and had slightly smaller guns. However, radar and early mechanical firefighters computers may have given her an edge of the optically-directed guns of the Yamato.
According to Weapons of World War II, the Imperial Japanese Navy (IJN) Yamato had nine 18.1-inch guns in three triple turrets. She also had six 6.1-inch guns and 24 5-inch anti-aircraft guns. She also had up to 150 one-inch anti-aircraft guns and 12 anti-aircraft rocket launchers. Each of her 18.1-inch guns had a range of 24 nautical miles (26 statute miles / 42 kilometers). The Yamato’s guns were able to penetrate up to 24-inches of armor at maximum range.
The Iowa-class battleships had nine 16-inch guns in three triple turrets. Each big gun had a range of 20.54 nautical miles (23.64 statute miles / 38 kilometers). The Iowa-class battleships also bristled with anti-aircraft guns as part of their carrier escort role. These included 20 5-inch guns, 80 1.6-inch guns, and 49 .8-inch guns.
Advantage: Yamato. The Yamato‘s big guns outraged the Iowa-class battleships by 3.5 nautical miles. That would mean the U.S.S. Iowa would have to steam several miles through Yamato‘s fire. Both ships could fire 2 rounds per minute from their main guns.
The Yamato had the heaviest armor and according to Weapons of World War II, her armor extended well below the waterline. At its thickest the Yamato’s side armor was 16.1 inches thick and her deck armor was 7.8 to 9.8-inches thick.
The Iowa class battleships were the first to have heavier armor on the decks than on the sides. This was undoubtedly due to the air threat and threat of “plunging fire” that the ship might face. The Iowa has deck armor that is approximately 14 inches thick and side armor that is 12.2 inches thick at its strongest.
Advantage: Yamato. The Japanese ship was built to be nearly impervious to 16-inch shells from Allied battleships. However, her guns were able to penetrate armor of the U.S.S. Iowa.
The IJN Yamato had excellent optical fire control directors to aim the big guns. However, she did not have radar or sophisticated “computers” to increase accuracy.
The Iowa had a Fire Control System with advanced mechanical computers to increase accuracy. The Iowa also had radar.
Advantage: Iowa. When it comes to fire control systems, the advantage lies with the Iowa-class battleships.
There are two types of battle that could be anticipated. First, the American battleship has to close range to be able to hit that Yamato. Tactically, that would be a disadvantage for the Iowa-class battleship. First, the Yamato could “cross the T” of the Iowa and turn broadside to the American battleship to fire all nine big guns. In the 6.36 minutes it would take for the Iowa to get into range, the Yamato could fire up 114 unanswered shots. Alternatively, the Yamato could turn tail and flee at 28 knots while firing her rear battery. In a running fight, it would take the U.S.S. Iowa 42 long minutes to catch the IJN Yamato. In that time span, if she had the magazine capacity, the Yamato could fire up to 252 unanswered shots.
Advantage: Yamato. While long range shots may not be the most accurate, when you are dropping 1.6 ton rounds that can penetrate up to 24 inches of steel, the recipient of your gunfire is going to have a bad day.
The Yamato had a sister ship the Musashi. But, by the end of the war, the Japanese Navy was bereft of air cover and low on fuel. In contrast, by the end of the war, the U.S. had four Iowa-class battleships and a staggering 140 aircraft carriers. According to Weapons of World War II, the United States attacked and sank the IJN Yamato with 386 aircraft. She absorbed 13 torpedo and 8 bomb hits before capsized and exploding.
Advantage: Iowa. World War 2 was not fought by individual ships. It was fought by fleets and squadrons. The industrial power of the United States provided the U.S.S. Iowa with a large and capable supporting cast for any battle. Since the American fleet was larger, it could likely have swarmed the Yamato and her escorts.
In single combat, the Yamato could well have sunk the U.S.S. Iowa. She had the firepower. However, in a surface fleet action, the numerically superior Americans would likely have prevailed. In history, both the Yamato and Musashi were sunk by air attack. The battle was won from the air and the U.S.S. Iowa never even had to show up.
Iowa-class Battleship, Wikipedia.org
Koenig, William, Epic Sea Battles, Chartwell Books, NJ, 1975
Japanese Battleship Yamato, Wikipedia.org
Ludeke, Alexander. Weapons of World War II, Parragon Press, Bath, UK, 2007.
Preston, Anthony. Jane’s Fighting Ships of World War II, Random House, 1994.
Iowa-Class Battleships- U.S. Naval History & Heritage Command
Japanese Navy Ships – Yamato, U.S. Naval History & Heritage Command