Key Points and Summary: In the late 1930s, Japan began designing the A-150, a “Super Yamato” battleship intended to surpass anything in the US Navy.
-This colossal warship, displacing 90,000 tons, would have boasted six 20-inch guns, the largest ever mounted on a battleship, and a top speed of 30 knots.
-Inspired by their victory over Russia in 1905, the Japanese aimed to overwhelm the US fleet with sheer size and firepower.
-However, the A-150 was ultimately deemed too ambitious. Technological limitations, resource constraints, the growing importance of aircraft carriers, and the demands of the war in China led to its cancellation.
20-Inch Guns and 90,000 Tons: Inside Japan’s A-150 Battleship Project
The Japanese Yamato-class battleships were the most significant vessels ever to steam the high seas. They were gargantuan dreadnoughts. Japan even had a plan to build a more enormous battleship – the A-150.
This would have outclassed almost anything in the world, assuredly dominated its region, and even overshadowed the best battleships from the U.S. Navy.
But the “Super Yamato-class” never came to fruition despite Japan’s grand ambitions.
Uber Large and Fast
Officially dubbed the Design A-150 battleship, work began in 1938. This ship would have a remarkable six 20-inch guns and would displace 90,000 long tons. The A-150 would also churn a top speed of 30 knots.
This was faster than the U.S. Navy’s North Carolina-class battleships, which could only manage 27 knots at top speed.
That was seen as exceptionally quick at the time.
Build It Before the United States Could React
Japan was worried about America’s ship-building industry and did not want to wake up a “sleeping giant” that could produce three ships for everyone that Japan could make.
So, the Japanese wanted to go with size and quality instead of just focusing on quantity. Why not make the A-150 so it was the most powerful ship in the world?
The idea was to overawe the American fleet.
Dominating the Russian Navy
The Japanese learned a valuable lesson when they destroyed the Russian fleet in the Battle of Tsushima Strait in 1905 during the Russo-Japanese War.
Japan’s navy was more sound structurally and strategically during that conflict. They used modern tactics against the Russians to sink six Tsar battleships and 14 other enemy vessels.
The number of Japan’s ships was superior, and the thinking was that Japan’s navy would continue to build large vessels for force-on-force naval battles that would be decisive and make the maritime branch a modern marvel.
Next Victim: the U.S. Navy
The next war would likely be against the United States, and Japan wanted more battleships to destroy the American fleet similarly by sending as many ships as possible to the bottom of the sea.
The A-150 would lead the charge with bigger guns and better armor – making the vessel survivable against anything the Americans could throw up against it.
The Japanese designers and engineers went to work.
Yamato-class battleship Yamato. Image Credit: Creative Commons
The A-150 would have massive 45-caliber 510mm guns in double or triple turrets. The warships aimed to have a number of 20-inch guns, the biggest on Earth, if this battleship was built.
This would equip the A-150 with the biggest guns ever on a battleship.
These were more significant armaments than what adorned the Yamato-class.
Since the A-150 was designed to be fast, too, it would be difficult for American shipyards to keep up with something similar. The U.S. Navy had nothing like the A-150.
What Became of the A-150?
However, the A-150 was a dream that never came true. The wish list of power and speed would be a bridge too far to make fast enough to win the war against the Americans.
The technology was not mature enough to usher in those big guns on such a large ship. It would be a tall order, and the shipbuilders were just not ready to construct such an ambitious project.
Moreover, the Japanese had to focus on the army, which became busy with the occupation of China and other territorial gains in East Asia. That sucked up men, money, and resources. What Japan imagined with the A-150, a 90,000-ton vessel, just wasn’t in the cards due to cost and the number of workers that would have been needed. The navy had to fight a war with what it had then, and the A-150 was never built. Time was not on Japan’s side either, and the A-150 would have taken many years to build.
Battleship Yamato Blueprint. Image Credit: Creative Commons.
Plus, the naval order of battle had changed by World War Two. This was the age of the aircraft carrier, and Japan needed naval aviation to match what the Americans were doing with their flat-tops. Battleships were not seen as the most decisive ships in the fleet, and the days of battleship-on-battleship battles were ending.
The A-150 was not needed, but it would have been a wonder had it been built, even though Japan did not have the capabilities to produce it. It will go down in history as one design to remember even though it never was to sail and fight the U.S. Navy.
Battleship Yamato-Class. Image Credit: Creative Commons.
About the Author: Dr. Brent M. Eastwood
Brent M. Eastwood, PhD, is the author of Don’t Turn Your Back On the World: a Conservative Foreign Policy and Humans, Machines, and Data: Future Trends in Warfare, plus two other books. Brent was the founder and CEO of a tech firm that predicted world events using artificial intelligence. He served as a legislative fellow for U.S. Senator Tim Scott and advised the senator on defense and foreign policy issues. He has taught at American University, George Washington University, and George Mason University. Brent is a former U.S. Army Infantry officer. He can be followed on X @BMEastwood.
NOTE: This piece has been updated to fix a small typo mistake.
