Did Japan Have An A-Bomb Program?

I know the Germans had an a-bomb program during WWII but I don’t remember hearing whether the Japanese had one also. Was there ever an atmoic bomb program in Japan during WWII?

There was reportedly a fledgling program, but I don’t think it went beyond paper studies. I think the information is in Richard Rhodes’ massive and indispensable book he Making of the Atomic Bomb. In his book Hiroshima, John Hersey says that within hours of the explosion there were circulating mimeographed explanations of it – so it was certainly being thought about.
In his science fiction World War series, Harry Turtledove depicts a Japan that is certainly aware of the basics of fassion and actively seeking to build a bomb, but Tokyo gets nuked first.

There were a number of small programmes being funded by different government agencies. At least some of those involved had a clear idea of what was involved, but the logistical obstacles meant that there was never the political/funding commitment for a serious attempt at building one. Most of the practical research was directed at isotope separation and the experiments reached an industrial size, but never on the massive scale that would have been required.
The FAS summarise the Japanese effort. It’s a subject where there’s very little material been published in English (or even, as far as I know, in Japanese).

As I’ve already mentioned in one of the other threads today, this old post of mine critically picks apart some of the wilder claims that have been made about the Japanese efforts.

Those Pesky “Big Uglys” and their “Not Empires!”. (I’m reading Homeward Bound right now :slight_smile: )

Another thread mentions they had a dirty bomb program (spread radioactive material via air-drop), but I’m not sure about a conventional fission program.


I haven’t read it, but John Dower has a 45-page essay entitled “NI and F: Japan’s Wartime Atomic Bomb Research” that seems to be on target. It’s included in his book Japan in War & Peace, which should be pretty available.

:confused: :confused: :confused:
Haven’t you seen Godzilla? :rolleyes:

Godzilla was awakened by an American bomb.

The dirty bomb suggestion is one of the “wilder claims” I mentioned above. See the old post linked to there and the comments I made in the other thread.

I was just pondering about the fact that suddenly we have a half dozen or so A-Bomb threads in GQ, then I noticed that they were all started by dolphinboy.

Do you have a term paper due or something?

And yet they insisted on wearing white sandals after Labor Day. Can you imagine?

I seem to recall that Germany was sending Japan all its uranium and/or heavy water when Germany was defeated and the sub was sent back.

Erm, what? Got any backing for this?

I heard this too, on one of the History Channel’s Last Days of WW2 episodes. A quick Google search found this movie about it: U-234: Hitler’s Last U-Boat.

Well I never. That does sound persuasive, although I’d like to see something more authoritative than a documentary about it. Thx!

I remember seeing the show on the History channel. The U-Boat also carried a disassembled ME-262 jet fighter plane. Some info here:

There’s a book about it too: Germany’s Last Mission to Japan: The Failed Voyage of U-234 by Joseph M. Scalia.

Scalia’s book is recommended. Given the substantial amount of rubbishy speculation that’s been written about the U-234 in the last decade or so, he did the useful exercise of looking at it in the wider context of attempts to carry out technology exchanges between the Axis powers. By explaining why all the other stuff and passengers were on board, he basically makes the whole mission far less mysterious.

The mission grew out of the undertaking between Germany and Japan, formalised in the likes of the Tripartite Pact in 1940, to pool the results of their military research. In practice, this proved a rather complicated affair even in the early stages of the war. There was a reluctance on both sides to reveal their best stuff, though they were able to gradually build up some trust over time. Another obstacle was the sheer difficulty of transferring men, plans and equipment halfway round the globe in the face of Allied forces. Submarines were a recourse of last resort. By the time U-234’s specific mission was planned there was no great expectation that it would be able to get through. Amongst other factors, Johann Fehler was hardly either the best trained or the most competent captain at Doenitz’s disposal.
In this sort of context, it’s not obvious that the uranium was an especially important part of the cargo. There was a lot of other stuff on board and all of that can be accounted for in ways that don’t bear on nuclear research. Nor were any of the passengers on board for such a reason. There’s even a somewhat mundane reason why uranium was attractive as a part of the shipment: because of contraints of space and ballast, especially dense material and equipment was preferred.
So why was the uranium on board? Scalia has identified a series of requests, starting in 1943, from Tokyo asking that the Germans send them uranium ore. While initially disguised with other explanations, the reason they wanted it was indeed for their bomb research. For the Japanese programmes had a huge problem: they didn’t know of any natural uranium deposits, either in Japan or in their conquered territories. They did eventually find ways around this scarcity, notably by locating a source in Korea and mining that. But even just finding enough uranium to experiment on, never mind solving the problem of getting sufficient to actually process for a reactor or bomb, remained a headache for them until the end. By contrast, uranium was one of the resources that the Germans had a good supply of. By the end of 1943 they’d agreed to send 1000 kg. Some of this was sent in earlier missions and it may even be that some got through.
Scalia also makes the interesting point that it wasn’t even as if the German nuclear programmes were the main call on their supply. Various armament projects were using it, in much the same way that it’s used in modern shells etc. These applications called for the ore to be refined into uranium oxide and then processed into metallic uranium plates. By the last stages of the war, Allied bombing had managed to disrupt this last industrial step and the production of metallic uranium had ground to a halt. It may be that what went on U-234 was redirected from the, now surplus, supply for such production.
Rather than any sort of enriched material for immediate incorporation into any sort of bomb, what was shipped was thus probably uranium oxide intended for use in Japanese research. With the Japanese project halted by this stage by Allied bombing, it’s not even as if they needed that. But there’s no reason to suppose that Tokyo had told Berlin that their research had stopped.

In an interview he did for Playboy, Akio Morita (founder of Sony) said he worked in the ‘special weapons’ division during the war. Most of his effort was on trying to build some kind of ‘death ray’ to fry enemy planes from the sky.

When Hiroshima happened he and the other scientists knew exactly what it was, but they were simply amazed that the Americans had been able to build one so quickly. As others have said Japan never came close to getting the resources together for a serious bomb-building effort, they sort of knew Germany hadn’t either, so they weren’t expecting that the US had.

This would be during the 1920’s wouldn’t it?

No… no term paper due. I haven’t been in school for 25 years. Just had some questions nagging at me that I wasn’t able to get good answers to anywhere.

When I was going to school there was no Internet or SDMB.

My parents (both alive) vividly remember when we dropped the “big ones” on Japan and both said it was done to end a war that was going to be long and bloody if we didn’t. Neither knew whether Japan or Germany had any atomic weapons program and both said they never heard of the Trinity Project so our secret was well kept at the time.

The orginal question was why didn’t we drop one on Tokyo and the answers I got helped put everything in perspective.

I’m bumping this because, having been alerted to it by cckerberos’s post above, I’ve now had a look at Dower’s essay and it’s worth commenting on.

Certainly the best discussion in English that I’ve seen, though for his specific details about the projects he’s almost entirely dependent on two particular accounts in Japanese. It seems, as is apparently well known amongst specialists on Japan in the period, that many of the government papers from the war were systematically destroyed between the surrender and the arrival of the occupation forces. Most of the original documentation from the projects were lost in this cull. However, many of the physicists involved were interviewed in the decades that followed and this provided a basis for the accounts Dower draws upon. One of these was a popular 1968 history of the Showa period, edited by Yomiuri Shimbunsha, which devoted 150 pages to a description of the projects. The other was a 1970 multi-volume history of Japanese science and technology. All the English accounts of the subject seem to ultimately predominately derive from these two sources, but Dower’s at least gone through them in the original versions.
Most of the essay isn’t a straightforward narrative of the projects, since he, entirely reasonably, wants to situate them within certain existing debates about Japanese society and nuclear technology. The main points he argues are:
[ul]Aside from the initial destruction of documents, there was no postwar attempt to hide the projects. There was a secret briefing to the US occupation authorities, but I suspect that secrecy - given the period in which it occured - was as much at the behest of the latter as the Japanese. As already noted, the participants were free to talk and the subject does seem to have been widely mentioned in the Japanese press in the years after the war.
Largely because of the language barrier, the matter wasn’t discussed in the US until 1978, when it was then presented as the unveiling of a postwar cover-up. Dower convincingly refutes this notion.[/ul]
[ul]The efforts were all fragmentary, underfunded and speculative. His interest here is them as an example in a much wider historical debate. While Japanese wartime propaganda was founded on the notion of national unity, with the whole society together in their aims, Dower is one of those historians who argue this was a myth. Not everybody was a slave to the ideals and even the government wasn’t coherently united.[/ul]
[ul]In each of the projects, the main impetus was from the military rather than the physicists. In keeping with the previous point, the scientists were not particularly behind the war effort and were mainly interested in securing their students on projects that prevented them being conscripted.[/ul]
Dower’s read an adequate amount of the literature on the Allied and German projects in order to roughly compare the Japanese efforts with them, but the obvious weakness of the essay is that he simply doesn’t pretend to understand the physics. He does try to give some context about Japanese physics in the period, though it’s a bit thin. Unsurprising - and understandable - weaknesses given what his interests in the topic are.

In the light of the discussion in the parallel thread, I’ll note that he claims that Japanese science fiction writers had picked up on the idea of atomic weapons prior to 1945. No, he doesn’t say who. There was also apparently a popular boys’ magazine that carried a story called “Atom Bomb” during the war.