The Japanese battlecruisers that forced the United States to build bigger ships
In short: In a high-stakes game of naval chess, Japan’s Kongō-class ships were so formidable they dictated American industrial policy. These vessels weren't just weapons; they were technological sponges, built in Britain and refined through decades of radical reconstruction to become the fastest battleships of their era.
The Kongō-class was born from a desperate need for parity with the British Royal Navy. Following the 1907 launch of HMS Invincible, which rendered existing Japanese designs obsolete, the IJN authorized an expansion bill in 1911. The resulting class was designed by British architect George Thurston. To ensure Japan could master this technology, Vickers built the lead ship, Kongō, in Britain while transferring naval secrets to over 200 Japanese specialists who spent up to 18 months on secondment.
The ships underwent a dramatic evolution of form and function. Originally designed as battlecruisers with ten 12-inch guns, they were modified mid-construction to carry eight 14-inch guns after trials proved the new caliber superior. In the late 1920s, they were reboilered and reclassified as battleships to comply with treaties. However, a massive second reconstruction in the late 1930s replaced their old boilers with eleven oil-fired Kampon units, pushing speeds past 30.5 knots. This transformation turned them into 'fast battleships'—the only Japanese ships capable of operating alongside fast aircraft carriers.
Their impact was profound enough to influence the U.S. Navy's procurement; the threat posed by these high-speed vessels directly influenced the decision to order the Iowa-class fast battleships. During World War II, they were among the most active capital ships in the Japanese fleet, participating in every major engagement from Pearl Harbor and Midway to Guadalcanal. While Haruna and Kirishima were lost at Guadalcanal in 1942, Kongō and Haruna continued to fight until their respective sinkings in late 1944 and July 1945.
Technologically, the class was a study in adaptation. Their secondary armament shifted from 15 cm casemate guns to 127 mm dual-purpose mounts for anti-aircraft defense. Even their light AA guns were a point of contention: while Haruna eventually carried 118 French-designed 25-millimeter guns, the weapons were plagued by severe design flaws, including excessive vibration and insufficient magazine size, making them largely ineffective against fast targets.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: Kongō-class battlecruiser
To cite this card, link to https://intellectplus.co.uk/app/wars-kong-class-battlecruiser.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in World wars era · More in Wars & Conflicts · Latest · A–Z · All topics
