Here's a crazy idea I just thought of.
Suppose that Fat Man is chosen over Little Boy for the initial atomic bomb mission. The bomb is loaded onto Enola Gay and dropped on Hiroshima in a mission similar to OTL. However, in this mission the detonator malfunctions. No signal is sent to the conventional explosives surrounding the plutonium core and the bomb does not detonate.
If I remember correctly, this bomb would not have detonated upon contact with the ground (as LIttle Boy would have in case of malfunction). So, the bomb makes it all the way to the ground on the parachutes -- intact. If there is still a chance of the bomb going off on impact, the bomb lands in the river in the center of the city (the aiming point was a bridge) and the water softens the impact enough to not cause a detonation. It lands in shallow enough water, however, that it can be recovered.
The Japanese start wondering what they have here and immediately try to recover the object that had been dropped. It's very heavy and of a design never seen before. Not knowing what it is, but figuring it's dangerous (why would an American aircraft have dropped it on a city which hadn't been attacked yet?), the device is transferred to a secure site for scientists and army officers to investigate it.
The Enola Gay reports that the bomb failed to detonate. After five days frantically trying to figure out what went wrong (instead of the three between missions IOTL), they decide to deploy Little Boy against Hiroshima. The Japanese note the exact same mission profile. This time, however, the bomb detonates successfully with the same results as IOTL. The city is leveled.
It doesn't take a Japanese rocket scientist to realize that whatever had been dropped five days earlier had been another of these very powerful bombs. The question is: can they figure out why it didn't work and use it against the Americans in case the Americans invade? At the very least, announcing that they've got the bomb will make the Americans think twice about making further attacks on the islands. However, how many of these devices do the Americans have?
Now to be fair, the captured bomb would be best used against American troops trying to invade during an Olympic-style invasion. I can't imagine the Americans not dropping more bombs to try to forestall use of the captured bomb against invading troops: the bomb would likely be useless against aircraft and I believe the Americans had air superiority at that point so we wouldn't have the additional bombs shot down.
On the other hand, the Americans don't know what happened with the detonator. What happens if the same malfunction were to occur with one of the other bombs? 2 out of 3 isn't good enough here, and 1 out of 2 on air drops is worse. Do the Americans want to risk putting more bombs in Japanese hands in case of malfunction? If the bomb detonates, good. If the bomb doesn't detonate you have to assume it can be used against you.
Note that in the Nagasaki mission IOTL the bomber spent so much time circling over Kokura that antiaircraft fire got close and there were reports fighters were on the way. That's why they shifted to Nagasaki, the alternate target. You can bet that all remaining fighters and antiaircraft cannons will be moved to cities like Kokura and Nagasaki which haven't been attacked yet. If a bomber containing one of these devices is shot down it also leaves open the possibility of a recovery if the device fails to detonate.
Something tells me the Americans are going start focusing a lot on Little Boy style devices. And if the Japanese have subs (possibly provided by the Germans earlier) and are able to sneak one of these weapons past the American forces, however unlikely that is, and head for San Francisco...
Suppose that Fat Man is chosen over Little Boy for the initial atomic bomb mission. The bomb is loaded onto Enola Gay and dropped on Hiroshima in a mission similar to OTL. However, in this mission the detonator malfunctions. No signal is sent to the conventional explosives surrounding the plutonium core and the bomb does not detonate.
If I remember correctly, this bomb would not have detonated upon contact with the ground (as LIttle Boy would have in case of malfunction). So, the bomb makes it all the way to the ground on the parachutes -- intact. If there is still a chance of the bomb going off on impact, the bomb lands in the river in the center of the city (the aiming point was a bridge) and the water softens the impact enough to not cause a detonation. It lands in shallow enough water, however, that it can be recovered.
The Japanese start wondering what they have here and immediately try to recover the object that had been dropped. It's very heavy and of a design never seen before. Not knowing what it is, but figuring it's dangerous (why would an American aircraft have dropped it on a city which hadn't been attacked yet?), the device is transferred to a secure site for scientists and army officers to investigate it.
The Enola Gay reports that the bomb failed to detonate. After five days frantically trying to figure out what went wrong (instead of the three between missions IOTL), they decide to deploy Little Boy against Hiroshima. The Japanese note the exact same mission profile. This time, however, the bomb detonates successfully with the same results as IOTL. The city is leveled.
It doesn't take a Japanese rocket scientist to realize that whatever had been dropped five days earlier had been another of these very powerful bombs. The question is: can they figure out why it didn't work and use it against the Americans in case the Americans invade? At the very least, announcing that they've got the bomb will make the Americans think twice about making further attacks on the islands. However, how many of these devices do the Americans have?
Now to be fair, the captured bomb would be best used against American troops trying to invade during an Olympic-style invasion. I can't imagine the Americans not dropping more bombs to try to forestall use of the captured bomb against invading troops: the bomb would likely be useless against aircraft and I believe the Americans had air superiority at that point so we wouldn't have the additional bombs shot down.
On the other hand, the Americans don't know what happened with the detonator. What happens if the same malfunction were to occur with one of the other bombs? 2 out of 3 isn't good enough here, and 1 out of 2 on air drops is worse. Do the Americans want to risk putting more bombs in Japanese hands in case of malfunction? If the bomb detonates, good. If the bomb doesn't detonate you have to assume it can be used against you.
Note that in the Nagasaki mission IOTL the bomber spent so much time circling over Kokura that antiaircraft fire got close and there were reports fighters were on the way. That's why they shifted to Nagasaki, the alternate target. You can bet that all remaining fighters and antiaircraft cannons will be moved to cities like Kokura and Nagasaki which haven't been attacked yet. If a bomber containing one of these devices is shot down it also leaves open the possibility of a recovery if the device fails to detonate.
Something tells me the Americans are going start focusing a lot on Little Boy style devices. And if the Japanese have subs (possibly provided by the Germans earlier) and are able to sneak one of these weapons past the American forces, however unlikely that is, and head for San Francisco...
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