Japanese Submarine That Could Launch Bomber Planes Like An Aircraft Carrier

The I-400: An Engineering Marvel of Japanese Naval History The I-400 submarine was a mammoth feat of engineering, a technological marvel tha...

The I-400: An Engineering Marvel of Japanese Naval History

The I-400 submarine was a mammoth feat of engineering, a technological marvel that embodied the ambitions and ingenuity of the Imperial Japanese Navy. With the capability to carry and launch three Aichi M6A Seiran attack planes, the I-400 stood as a potent symbol of Japan's ambition to extend its reach across the Pacific during World War II. In this article, we will explore the history, design, and legacy of the I-400 submarine.

The Concept

In the early 1940s, Japanese planners recognized the need for a long-range strategic bomber capable of reaching targets beyond the range of existing aircraft. To achieve this, they proposed a submarine-based aircraft carrier, a concept that had not been previously attempted on such a scale. The I-400 was designed as a key component of this strategy, with the primary goal of providing a platform to launch and recover attack planes in distant waters.

Design And Features

The I-400 was designed to be 400 feet (122 meters) long and capable of carrying three
Aichi M6A Seiran attack planes in a waterproof hangar within its hull. It was powered by four diesel engines and could reach a speed of 18 knots (33 kilometers per hour) on the surface and 6.5 knots (12 kilometers per hour) submerged. The submarine had a range of 37,500 nautical miles (69,500 kilometers) on the surface and 105 nautical miles (194 kilometers) submerged.

Launch and Recovery of Aircraft

One of the most remarkable features of the I-400 was its ability to launch and recover aircraft while submerged. The submarine's hangar was equipped with a hydraulic lift that could raise the planes to the surface, where they would be launched using compressed air. After completing their mission, the planes would return to the submarine and be retrieved using a crane. This capability allowed the I-400 to operate independently, without the need for a surface fleet.

Operational History

The I-400 was commissioned in December 1944 and assigned to the 1st Submarine Flotilla, where it underwent training and testing. Its first and only operational mission was a planned attack on the Panama Canal, which was aborted due to Japan's surrender in August 1945. After the war, the I-400 was captured by the United States and eventually scuttled off the coast of Hawaii in 1946.

Legacy

Despite its short operational history, the I-400 remains a symbol of Japanese engineering and innovation. Its design and capabilities were far ahead of their time, and the submarine's ability to launch and recover aircraft while submerged foreshadowed the development of modern ballistic missile submarines. The I-400 also played a role in the post-war arms race, as the United States and Soviet Union sought to replicate its technology and capabilities.

Conclusion

The I-400 submarine was a testament to the ingenuity and ambition of the Imperial Japanese Navy. Its innovative design and capabilities paved the way for the development of modern submarines and influenced the course of naval warfare in the latter half of the 20th century. While its operational history was brief, the I-400 remains an enduring symbol of Japan's technological prowess and military ambitions during World War II.