https://web.archive.org/web/20031229125 ... D=58.topicBIG NOTE: A good portion of Stuart's posts from this weren't archived by the Internet Archive; the original thread can only be regarded as partially recovered
Subject: German Nuclear Weapons Program
Posted By: Seer Stuart The Prince of Darkness
Posted At: 10/27/02 17:10
Every so often, the proposition that Nazi Germany was on the verge of deploying a workable nuclear device comes up (recently we had the rather risible suggestion here that the Germans could have had a nuclear device in 1946 - why that was so daft will become obvious in due course). Usually, these claims are in the context of how if the Nazis had only done this or that they would have won the Second World War. I thought it would be interesting to look at the reality of the German nuclear weapons program since not only does it show that German scientists in WW2 couldn't find their ass with both hands and a roadmap but the story itself has a low humor that is quite irresistible.
A word on where all this comes from. The primary source was an operation called Alsos. Alsos was an intelligence operation run between 1942 and 1946 that attempted to discover who else was working on nuclear devices and how their work was progressing. Hence the name, looking at who also were developing nuclear technology. Alsos-A looked at Germany, Alsos-B at Japan and Alsos-C at the USSR. A putative Alsos-D would have looked at other possibilities. The joke is that the name itself also became a significant security breech since General Groves got to hear of the name and immediately noted that Alsos is Greek for Groves. He threw a fit but changing the name would have drawn attention to it so it stayed put. The other source is the Farm Hall transcripts - the German nuclear scientists were held at a place called Farm Hall between July 3, 1945 and January 3 1946 for interrogation. Their rooms were wired of course so their private conversations were recorded as well as their formal interrogations. The results can basically be summed up by the succinct comments of one of the Manhattan District engineers "Who are these clowns?"
The German nuclear weapons development program started in 1938 with a program to develop nuclear physics being started under the Heereswaffenamt (Army Ordnance Research Department). On September 26th 1939, Werner Heisenberg was conscripted into this department which now had the unofficial nickname of Uranverein (Uranium Club). Although Heisenberg was a brilliant theoretician he was a very poor experimentalist and an even worse administrator - a combination of traits that was to have dire effects on the program. Through 1940 and 1941, German scientists focused on two lines of research - how to make a chain-reacting pile and how to separate U-235. These were carried out at the Kaiser Wilhelm Institute in Berlin (under Heisenberg) and the Army Research Laboratory at Gottow (under Kurt Deibner).
The second of these research aims failed completely. German scientists were unable to devise a means of separating U-235 from U-238 and were thus unable to produce weapons-grade enriched uranium. Thus, any German nuclear device would have to use plutonium, produced by bombarding U-238 with neutrons in a nuclear reactor. Thus, the Deibner group was terminated in June 1942 and all the efforts concentrated on Heisenbergs group. The task was now defined; first make a reactor that could produce plutonium from U-238, then design and build a device from that Pu-239.
In order to make a reactor, it was first necessary to design it. Reactors require a moderator to slow down the neutrons so they can then be captured by the target nucleus. The most suitable moderators are very pure graphite or heavy water (deuterium oxide). Enter Walther Bothe, the scientist assigned to select the most suitable moderator. Bothe was incredibly careless and/or stupid (he was hopelessly in love with Ingeborg Moershner at the time and described his days in a letter to her as "speaking physics and thinking of you"). He failed to notice that his graphite samples were heavily contaminated with boron and cadmium, both ravenous neutron absorbers. As a result, he concluded that graphite was useless as a moderator and he opted for the use of heavy water. The next year was spent in a dance over heavy water supplies.
The only source of heavy water in Europe was the Norsk Hydro plant in the Rjukan Valley, about 75 miles west of Oslo. This has been built in 1934 and was seized by the Germans in 1940. By 1942, it was shipping approximately one ton of heavy water per year to Germany for use in reactor experiments. News of this quickly reached the Allies who took it as proof positive that the Germans were working on a reactor that could produce Pu-239. The plant would have to go. The British tried a commando raid on November 20 1942. Both the gliders used to deliver the commandos crashed in bad weather, many commandos being killed and most of the rest badly wounded. They surrendered without a fight expecting medical treatment for their wounded. Instead General von Falkenhorst had them all summarily murdered (he was sentenced to death for this after the war but, sadly, was reprieved in 1953). However, a second commando raid in February 1943 was much more successful; nine commandos infiltrated the plant and blew up the heavy water cells and six months production of heavy water. The plant was out of action until August 1943 but had barely resumed work when 174 B-17s plastered the factory with bombs. Although damage was slight, the Germans decided to dismantle the plant and rebuild it in Germany. In effect, heavy water production ended in Europe with this decision.
This left 14 tons of heavy water in Norway. The Germans loaded it into 49 drums, took them by train to Mael where they were to be loaded onto a rail ferry across the lake. The Norwegian resistance placed a mine on the ferry and sank it half way over the lake; 45 drums went to the bottom, only four partially-filled drums were salvaged. One of the saboteurs discovered that his (cantankerous) mother in law planned to take this ferry. On the pleas of his wife, he stopped her by mixing business with pleasure and feeding the old lady a huge dose of laxative (she had to be really, really ill because the Germans would look with great interest at everybody who was supposed to be on the ferry and wasn't). Sure enough, the gestapo arrived and interviewed the family. The mother in law spent the whole time being obnoxious, foul-tempered and accusing her son in law of poisoning her. The investigator was much touched by the devotion of this young couple in looking after a sickly but horrendous old harridan and, as he left, put his arm around the young husband's shoulder and said confidentially "you know, I would have quite understood if you had poisoned her"
Almost all the precious heavy water was irretrievably lost. That left just the supplies already in Germany. Or, rather, had. Heisenberg was a dreadful administrator; the work schedules he organized frequently left the laboratory in the charge of unqualified staff - or completely unattended. On June 23, 1942, the heavy water in an experimental reactor leaked into the uranium, liberated hydrogen and the reactor exploded. The laboratory, all the heavy water and the research documentation was all destroyed. German research was set back two years at least.
In fact it was much worse than that. It quickly became obvious that there were years of research work and engineering needed before a reactor could be built. A year later so little progress had bene made that the German atomic bomb program was canceled in July 1943. All the Uranium supplies in Germany were transferred to a German Army program aimed at using the material in armor-piercing shells for tanks (note; the natural uranium including the precious U-235, not the depleted uranium used now by the US). At that time the allies were plotting various means of stealing said uranium and/or destroying the source of supply. Little did they know the Germans literally intended to throw the stuff at them gratis. Thus, from mid-1943 onwards the German nuclear weapons development program was dead. No work on weaponizing nuclear research continued past this point. Hence the idiocy of claiming the Germans could have had a nuclear device in 1946.
However, some research on reactors did continue. A small atomic pile was built in a place called Haigerloch (near Hechingen) for neutron-multiplication calculations. This facility used all the remaining heavy water supplies in Europe (1.5 tons). This work showed that the reactor would have to be doubled in size before a sustained chain reaction could be maintained - and, of course, there was no more heavy water to moderate it. So that work to was abandoned. The pile, the scientists, the heavy water and all the uranium ore (still sitting in Army sheds waiting to be turned into tank ammunition) was captured by the US Army by February 24th 1945 and shipped to the USA.
And that was it. The Germans hadn't even begun to produce the tools needed to produce the equipment needed to produce the material needed for experiments in designing a workable device. The Germans didn't have the resources to follow all the possible routes to a workable device so they had to pick one and go with it. They picked the wrong one. Then, their poor scientific method and base incompetence meant that they blew that (in the case of their laboratory pile, quite literally).
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Subject: Re: German Nuclear Weapons Program #4
Posted By: Urgit Linuxphile
Posted At: 10/30/02 14:16
Are there books on this subject that you would reccomend? specifically on non-American nuclear weapons programs ( or British after the war ).
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Subject: Re: German Nuclear Weapons Program #5
Posted By: Seer Stuart The Prince of Darkness
Posted At: 10/31/02 3:09
The most succinct source on the German nuclear development program is contained in a book called "Building the Bombs" by Charles R Loeber and published by Sandia National Laboratories. Its a US Government publication. If you want to go deep into this, some necessary reading is as follows
The Farm Hall transcripts are publically available in "Hitler's Uranium Club" by Jeremy Bernstein (AIP Press 1996). An alternative view of Heisenberg's actions can be read in "Heisenberg's War" by Thomas A Powers (Alfred A Knopf 1993). The Norwegian Heavy Water Campaign is best described in "Blood and Water" by Dan Kurtzman (Henry Holt, 1997) and "Heavy Water and the Wartime Race for Nuclear Energy" by Per F Dahl (Bristol and Philadelphia Institute of Physics Publishing, 1999).
Perhaps the most serious lesson from the last two books is - don't mess with Norwegians.
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Subject: Re: German Nuclear Weapons Program #6
Posted By: mekozak Old Friend
Posted At: 10/31/02 18:39
As a general reference to the development of the atomic bomb, I would recommend Richard Rhodes, "The Making of the Atomic Bomb".
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Subject: Re: German Nuclear Weapons Program #7
Posted By: schudak Old Friend
Posted At: 7/30/03 2:22
Given that estimation, either Bohr or Heisenberg was totally out of mind.I think the best comment on the Heisenberg-as-saboteur theory was made by Niels Bohr. In September 1941, Heisenberg went to Copenhagen and met with Bohr. Bohr was quite convinced that Heisenberg was genuinely trying to build a nuclear device, was trying to recruit Bohr for the work and, failing that, trying to pump him for information on likely allied work.
Lets assume that Bohrs estimation of Heisenbergs intend is correct. Then Heisenberg made the following mistakes:
- he must have been totally unaware of the situation of Jews (despite loosing many valuable Jewish members of his staff to the enforced emigration), believing that Bohr would have been allowed to help, and believing that Bohr would help despite the antisemitism of the NAZI-regime
- he must have believed that the Bohr, a Dane, would help not only Germany but Hitler in building a Bomb
- he had to unveil the existence of the German a-bomb-program just to ask Bohr to help him, committing a SERIOUS breach of secrecy
Failing that, he tried to pump Bohr for information on an Allied bomb-program? A man who lived in Denmark?
If Bohrs estimation is correct, then Heisenberg was the most naive man walking the continent at that time.
It should be noted that Heisenberg and Bohr could never agree on the content of the meeting - they could not even agree on the place. What happened is that after the meeting Bohr knew (from Heisenberg) that there was some kind of a-bomb-project in Germany and BELIEVED that Heisenberg wanted his help in stopping the Allies from doing such a project.
While the deep friendship that existed between these two men ended, they did resume a friendly relationship, agreeing not to discuss the past.Bohr was deeply offended by Heisenberg's approaches (previously the men had been close friends) and their friendship ended.
Kind of. He was already in Sweden, fleeing thanks to the individual courage of Georg Duckwitz who warned all the Danish Jews of the impeding deportation (and subsequent murder). Thanks to him, only 450 of the 8000 Danish Jews where deported, the rest managed to escape to Sweden. From there Bohr took the (long offered) plane to England.Bohr subsequently departed courtesy of the RAF.
There is no indication in the Farm Hall protocols that Heisenberg ever doubted his managerial competence. He probably never saw himself as managing anything but his own institute. When he stated the problems of creating a bomb there was no need for him to exagerate the problems. After the war he often stated that he (and others) were spared the actual decision wether to build a bomb or not by the sheer size of the project. And being on the wrong path in some aspects did not make the project smaller. Unlike some others Heisenberg never claimed to have deliberately sabotaged the project of a German a-bomb.Was he genuinely disrupting the program or covering his ass against an investigation that would have revealed his managerial incompetence?
However, there are some facets in the story that can be best explained if one assumes that he did not press for a success and tried to reach an understanding with the scientist in the west to not build such an device. From that attempt of communication only the fact that a German a-bomb-project did exist was noted, and probably played its part in the urgency to fund Manhattan despite its size. Honestly assuming anything else would have been irresponsible by the Allies, and THEY could afford to wage WWII and spending all that money into a technology that imho prevented WWIII.
When Heisenberg later, in late 41 and early 42, realized (wrongly, but that was not apparent to him) that the a-bomb would demand immense resources exceeding the wartime-capabilities of Germany he was content to believe that the Allies could (or at least would) not mount such an effort, too. So the German a-bomb-project died a quite death in 1942 - or at least it went into stasis until a reactor was created that produced plutonium.
Lack of coordination and a concentrated effort certainly played a huge part in the failure of the German project, too. But its unfair to blame Heisenberg here, for he was not the one in charge of the organizational effort.
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Subject: Re: German Nuclear Weapons Program #11
Posted By: Theodore Resident Vexillologist
Posted At: 10/28/02 1:15
A fascinating read, Stuart, thanks. I nominate this (and the Heisenburg appendix) for archival in the Essays section.
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Subject: Re: German Nuclear Weapons Program #12
Posted By: schudak Old Friend
Posted At: 7/30/03 2:32
One should also note the third and totally independent group working on a reactor under Max von Ardenne, who was organizationally under the post ministry (weired...). He worked for the Soviets after the war and was instrumental in their catchup in the nuclear race.German scientists focused on two lines of research - how to make a chain-reacting pile and how to separate U-235. These were carried out at the Kaiser Wilhelm Institute in Berlin (under Heisenberg) and the Army Research Laboratory at Gottow (under Kurt Deibner).
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Wayne Clark
Mon Oct 06, 2008 3:29 pm
From this essay, it appears that the main problem was that the Germans didn't know how to put the pieces together, not that they didn't have the resources. Is that right? If they somehow had figured out the right design, either for a gun-type or an implosion-type bomb, could they have built one? Was the industrial base there for it? (Probably not, my intuition tells me, since obtaining the necessary fissile material for Fat Man and Little Boy took a huge industrial effort by a power not under attack, one that a Germany under siege would find almost impossible to match, but I don't know).
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Seer Stuart
Mon Oct 06, 2008 4:21 pm
It's actually both. They didn't have the resources, after all, look at the amount the U.S. invested in the Manhatten Engineering District over a period of years. Germany simply didn't have that level of production capacity to devote to a master project like that. But, also, Germany didn't have the scientists to put the right pieces together or the engineers to make it an attainable reality. If I had to rank the five powers in degree of nuclear progress, I'd put Germany right at the bottom, below even Japan.
US
UK
USSR
Japan
Germany
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