Almost as peculiar as the ‘Bat Bomb’ idea of the US military (featured in a recent EG article) was a similarly outlandish scheme dreamed up by the Japanese, also in WWII. Yes, the Japanese came up with an idea of their own, for bombing the US mainland: Fu-Go balloon bombs, first launched in November 1944.
Made by housewives and school children from paper, cloth and rope, these unlikely weapons were intended to be transported by high altitude jet streams – 200 mph winds travelling at 30,000 ft – which would theoretically carry them to their target in three to four days. This madcap scheme was dreamed up by Japanese Ninth Army Technical Research Laboratory chief, Major-General Sueyoshi Kusaba. The plan was to have the balloons create mysterious blasts across the US – mysterious because the incendiary elements of the bombs would burn up all the evidence.
Around 32 ft in diameter, the balloons were to have anti-personnel explosives and incendiary devices slung beneath them. Each balloon could lift some 1,000 pounds in weight, 200 of which was sand bag ballast. The balloon was filled with hydrogen at the onset of the balloon’s journey, and an altimeter trip-switch would release gas if the balloon got too high or drop sand if it dipped too low. The device was timed to be over the target within a predetermined timescale, and when it was assumed it had made it there, the bombs would release, after which an 84-minute incendiary fuse would be ignited to facilitate self-destruction.
This truly was low-cost warfare. The balloons were constructed mostly by school kids, who pasted squares of washi paper together, with no idea what they were working on, for up to eleven hours a day. Although there were some 9,000 of these supposedly lethal weapons deployed, very few actually reached their intended target.
There were casualties, however. Six people were killed in Oregon by one of the devices when one of them tried to investigate it and the explosives went off. Yet another device actually did start a small fire in a forest, which the Japanese high command had hoped would happen on a large scale, but the blaze was put out quickly. One balloon bomb did also collide with an electric power line at the Hanford Site in Washington, shutting down production of plutonium for the world’s first atom bomb.
Michell Monument, for US victims of a Fu-Go bomb
Most of the bombs failed, though, because they were simply too big and far too numerous. Mid-air explosions were observed near the California coast, and initially it was thought that the balloons were being released from submarines off the US West Coast. When a squadron of P-47 fighter planes spotted a balloon bomb while on coastal patrol, they managed to recover it because the bombs failed to explode, and so the Japanese secret was out. News of this plot was heavily censored, but in truth those behind the scheme got all their estimates wrong, and the balloon bomb campaign failed utterly.