Wikimedia Commons/U.S. Navy
The USS Barb performed what would be the only U.S. ground operation on the Japanese home islands.
In the closing months of World War II, heavy losses and depleted fuel stocks kept many of Japan’s remaining combat aircraft grounded and warships in port, awaiting an anticipated amphibious invasion. Starting in July 1945, Allied battleships embarked on a series of naval bombardments of coastal cities in Japan in an effort to draw these forces out to battle—with little success. However, a week before the battleships began lobbing their massive shells, a legendary U.S. submarine toting a rocket launcher began its own campaign of coastal terror that foretold the future of naval warfare—and also engaged in the only Allied ground-combat operation on Japanese home-island soil.
Submarines still made use of deck guns during World War II, most of them ranging between three and five inches in caliber. These were used to finish off unarmed merchant ships or sink smaller vessels that could evade torpedoes—but also were occasionally directed to bombard coastal targets, such as in early-war Japanese raids on the coasts of California and Australia. The problem was that a single gun was unlikely to inflict much damage in a short amount of time, and the submarines were highly vulnerable to air, sea and land attack as long as they remained surfaced.
In 1942, the German Kriegsmarine actually tested submarine rocket artillery that could be fired underwater, but gave up on the idea due to its impracticality. Rumors that Germany had modified their subs to launch V-2 ballistic missiles at the United States led to a vigorous and bloody submarine hunt  in the closing weeks of World War II.
This story was originally published by The National Interest
The U.S. Navy, meanwhile, considered a much cruder solution: taking one of the Mark 51 rocket launchers it used on some of its LSM landing ships and strapping it to the main deck of a submarine. The twelve spin-stabilized 127-millimeter rockets mounted on the launch rack could only be fired while surfaced, and had a maximum range of three miles. However, a full volley could be ripple fired in the space of five seconds. The fixed launcher was unable to traverse, so the entire submarine had to turn to adjust the aim laterally.
Capt. Eugene Fluckey of the Gato-class submarine USS Barb volunteered his boat to try out the experimental rocket launcher in 1945. At the time, the Navy was actually testing the weapon’s viability as an anti-kamikaze weapon, but Fluckey managed to cajole the R&D staff into releasing the Mark 51 in time for his patrol, making the Barb the only rocket-launching submarine of the U.S. Navy in the conflict. You can check out footage of the rocket launcher on the Barb here .
The Barb, which displaced 2,400 tons submerged, was one of the top-scoring Allied submarines of World War II. By the most conservative count, it sank seventeen ships totaling ninety-seven thousand tons of shipping. Other tallies are considerably higher.
In January 1945, […]