A Review of the German Nuclear Weapons Project

Sam Turchetta
February 27, 2019

Submitted as coursework for PH241, Stanford University, Winter 2018

The Uranverein

Fig. 1: German Nuclear Weapons Project workin on a nuclear pile at Haigerloch. (Source: Wikimedia Commons)

The German Nuclear Weapons Project was an organized scientific program designed by Germany to produce nuclear weapons to combat the allied forces in World War II. In December 1938, Otto Hahn, and his assistant, discovered nuclear fission, which happens after blasting Uranium with neutrons. This discovery showed the German government that weapons of mass destruction could be created from relatively small matter, Uranium, leading them to create the First Uranverein. The Uranverein, or "Uranium Club," was created after seeing the benefits of nuclear chain reactions for the military. The group invited many well respected German physicists hoping to find a way to get a sustained nuclear chain reaction that could have a large impact on the targeted area. However, after 3 months of work, the group was terminated due to three of the researchers being called into military training, ending the first of two Uranverein's. [1]

The Second Uranverein formed a month after the first one was terminated, and continued to work until the end of World War II in 1945. Many notable names were in the group, including Werner Heisenberg, Carl Friedrich von Weizsacker, Otto Hahn, and more. This powerhouse of German physicists was made to beat the United States in the race to make a nuclear weapon. Heisenberg is regarded as one of the most important physicists in history, given his contributions to quantum physics. He relates important works from Kant or Descartes into his findings that helped him warn a Nobel prize. Having this individual among those developing weapons for the Germans was a blessing. [2] After Heisenberg reported that the enrichment of U-235 in Uranium was the best and only way to create explosives exponentially stronger than any every seen before. After this report was given to the German Army Weapons Bureau the Germans were able to get its first ton of Uranium delivered. After the Uranverein struggled to produce results for multiple years, the army decided to cut all things that would not give beneficial results in the near future. This could be related to the loss of many Jewish physicists who decided to work for the Allied forces. [3] This led to Heisenberg reporting to the German government that their support was a necessity for nuclear physics. This was because they talked about how nuclear weapons could be utilized as weapons for the army. However, months later Heisenberg told Speer, a leader of the government committee, that an atomic bomb could not be built until 1945 and would need a lot of resources to achieve that, forcing Speer to focus on closer possible achievements and lowering the priority of the German Nuclear Weapons project. In the end, the Uranverein was unable to beat the United States in the race for nuclear weapons and it cost them World War II.

The Uranverein vs. The Manhattan Project

The German Nuclear Weapons Project was the Germans equivalent to the United States's Manhattan Project. Fig.1 shows some of the developers of nuclear weapons working on the Project. Although the two were meant to race to see who could create a nuclear weapon that could be used to help win the war. The question is how did the United States seem to win the race by a landslide despite Germany having a large head start due to their discovery of nuclear fission before the United States and Germany having some of the most innovative scientists? There are a couple reasons that seem evident. First, the Manhattan Project was incredibly well coordinated, with 120,000 workers on the project in over 37 different factories and development facilities all over the U.S. While the United States show this large commitment, the Germans seemed to not believe this investment would pan out, so they limited the funds allocated to the German Nuclear Weapons Project. This moderate approach to fission reactors caused the German to fall behind. Secondly, some of the greatest physic minds fled Germany due to being in fear of Hitler. These same brilliant scientists moved on to work with Manhattan Project and greatly help the United States's effort. These factors led to the United States leading the world into the nuclear age, instead of Germany. [1]

Disorganization of the German Nuclear Weapons Project

The Uranverein was constantly embroiled in failures to communicate properly and and overall lack of organization. This was due to many factors. First, the scientists seemed disconnected a great deal of the time. For example, Heisenberg stated the relevance of nuclear fissions and the real world appliance it had on weaponry for the military and many scientists were surprised at the fact that they were working to create an explosive bomb. This lack of communication clearly inhibited the overall process. Similarly, at the top of the German government the communication was poor. This was due to Sheer, the overseer of the project, being scared to go to Hitler despite having limited successful results to give to him. This lack of communication caused the project to be destined for failure. Also, Heisenberg incorrectly calculated that the critical mass needed for a U-235 nuclear weapon was around 2-3 tons instead of the correct 15-60 kg. This definitely made the process harder.

© Sam Turchetta. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] P. L. Rose, Heisenberg and the Nazi Atomic Bomb Project (University of California Press, 1998).

[2] Werner Heisenberg, Physics and Philosophy (Harper, 1958).

[3] A. Wendorff, German Nuclear Program Before and During World War II, Physics 241, Stanford University, Winter 2014.