An Engineering History of the Manhattan Project
24 comments
·September 11, 2025mclau157
Before there was any bomb there was the Chicago Pile-1 in the middle of Chicago in a space under the stands at Stagg Field originally built as a rackets court
A wooden frame supported an elliptical-shaped structure, 20 feet high, 6 feet wide at the ends and 25 feet across the middle. It contained 6 short tons of uranium metal, 50 short tons of uranium oxide and 400 short tons of graphite, at an estimated cost of $2.7 million. According to Robert Crease, CP-1 and preceding piles were "the largest unbonded masonry structures since the pyramids.
On December 2, 1942, Fermi announced that the pile had gone critical at 15:25. Fermi switched the scale on the recorder to accommodate the rapidly increasing electric current from the boron trifluoride detector. He wanted to test the control circuits, but after 28 minutes, the alarm bells went off to notify everyone that the neutron flux had passed the preset safety level, and he ordered Zinn to release the zip. The reaction rapidly halted. The pile had run for about 4.5 minutes at about 0.5 watts. Wigner opened a bottle of Chianti, which they drank from paper cups.
HPsquared
Was there ever a radiation hazard from that or a big cleanup? Seems very "early days safety standards".
toxic72
I have in my possession a chunk of one of those graphite bricks. Very neat piece of history.
cactusfrog
One of the best books I’ve ever read is The Making of the Atomic Bomb Book by Richard Rhodes. If you want an extremely in-depth history of the science and people behind Manhattan project, I would highly recommend reading it.
bruckie
Seconded. I tell people it's several books in one, all of which are brilliantly executed:
- Biographies of the preeminent scientists of the 20th century
- A history of late 19th and early 20th century physics and chemistry. Much more technical than many history books, which is a drawback for some audiences, but probably an attraction for a lot of people here.
- A history of World War I and World War II
- A history of the engineering and operation of the Manhattan Project
Highly, highly recommended for this audience.
One caveat: I tried the audiobook and couldn't stand the narrator. Your mileage may vary, but I recommend reading it.
adastra22
Don’t forget the very last chapter: a gruesome moment by moment portrayal of the effects of the atomic bomb on the people of Hiroshima.
wanderingmoose
If you want a book that is more technical and really gives a sense of what the scope of the project was, I'd highly recommend The Los Alamos Primer by Serber which was the intro lecture given to scientists when they would arrive. Serber did a great job of annotating the lecture to explain in more accessible detail each section. A quick read, and well worth it.
foo70
100% agree. Also, if you liked that, try his follow on, "Dark Sun", focusing on the fusion bomb development after the war. There is probably a much greater focus on politics, especially involving Teller.
sklargh
Dark Sun is not bad, but it is definitely overshadowed by Rhodes' magnum opus.
I recommend Igniting the Light Elements for people who want a keystone piece about the early thermonuclear. https://www.osti.gov/servlets/purl/10596 - it's an extensive Thesis on the history of early thermonuclear period. Also one of the last comprehensive looks before classification fully obscures the plurality of the programs.
dboreham
Thanks for posting that reference. I came to do the same after finding that thesis while searching for another book I remember reading. The book covered Wheeler's (I think it was Wheeler) work simulating the first thermonuclear device on borrowed IBM calculating machines in the basement of some place in NYC (I think it was a commercial organization), basically beginning the HPC industry. Anyway, the Fitzpatrick thesis begins asking why it took so long for thermonuclear devices to be developed. I haven't yet had time to read to the conclusion, but presumably "not fast enough computers" is the answer.
Update, I tracked down the book. The guy was Ford, who worked for Wheeler: https://pubs.aip.org/physicstoday/article/68/7/46/415213/Bui...
LABerthier
He was definitely trying to impart more of a lesson with Dark Sun
next_xibalba
The first half of this book is kind of a slog, focusing on the minutiae of the Soviet's espionage effort. Which, to be fair, was the basis for the Soviet's rapid development of fission and fusion weapons. I just wasn't expecting a (rather boring) spy book. The 2nd half is much more interesting as they get into the truly genius science and engineering of the hydrogen bomb. And boy, Teller really does come off as a complete jerk who wasted a lot of time on his preferred Super design.
beezle
While Serber's book is good, if you really want to know the technical details about Manhattan/project Y, get a copy of Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years (1943-45) ISBN 978-0521541176 in paper (can't speak to quality, I have the hard cover). It is quite accessible.
spoiler:
probably the biggest engineering problem was the explosive lens
pontifk8r
I really enjoyed S.L. Sanger’s book “Hanford and the Bomb: An oral history of World War II” - but it’s out of print now and used ones? Sheesh!
hirvi74
My grandfather worked on the Manhattan Project! I am not certain of what meaningful contributions, if any, my grandfather had nor how long he was apart of the project, but I am confident that he remained in NYC for the entirety of his work -- never in Los Alamos to my knowledge.
Nevertheless, I remember asking him what was it like to actually work on the project. He said that it was far less Hollywood-esque than many would imagine -- at least for him. He was just given math/engineering problems and was asked to solve them with no context. He never knew what he was truly working on, why he was working on these problems, etc.. The work was pretty isolating and contact was with others was pretty minimal. I do know that he met both Von Neumann and Oppenheimer on at least one occasion which is pretty awesome.
I wish I could find some records, but I do not even know where to look.
theresistor
My grandfather also worked on it, as a technician in Los Alamos.
He had previously been working for a scientific supplies company in Chicago that was (unbeknownst to him) providing supplies to the Manhattan Project. Apparently his boss was aware of it, and when my grandfather's draft was called a letter from his boss convinced the draft board to assign him to Los Alamos instead. He was eventually able to get my grandmother, a secretary and typist, a job as a secretary in Los Alamos as well so that she could join him. She teased him the rest of their lives, because as the secretary to someone more important than a lowly technician, she had technically had a higher security clearance than he ever did!
The Atomic Heritage Foundation collects records about people who were affiliated with the Manhattan Project, as well as oral histories. Perhaps they have more information about your grandfather's work? See here: https://ahf.nuclearmuseum.org/ahf/bios/
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colechristensen
>I wish I could find some records, but I do not even know where to look.
The National Atomic Testing Museum in Las Vegas had a room full of file cabinets full of records you could look through the last time I was there, that might be a start.
Maybe one of the national labs that currently works on stuff has public records?
ricksunny
The Atomic History Museum in LV does not allow casual perusing of their stacks, unfortunately. They will refer you to online NTS archives, and the vast majority of those available (post-declassification) are about radiation effects on biology particularly as regards historical incidents of radiation hazards. Oh, and, no index so you never know if you are seeing the entire universe of documents available. An archivist’s travesty, IMO.
catigula
Question: are there any other known "Manhattan projects" and if not, why not?
ricksunny
Answering the question is a tautology. If there were any other extant Manhattan Projects, we would not citably known about it because, being a ‘Manhattan Project’, it would be replete with secrecy, including disinformation to keep the public from giving leaks about it any credibility. (case example, the Alamogordo Trinity test was called an ammunition explosion accident, by way of an Army Air Forces colonel, for the benefit of the good people of nearby Albuquerque).
Many today suspect the UAP study subject as being an ongoing decades-long Manhattan Project, from the late 1940s onward.
crazygringo
Not sure what you mean. Atomic bomb projects in other countries? Of course. Other large-scale engineering-led national projects? Yes, like the moon landing.
ambyra
Podcast/narrated version would be cool.
From the article: The alpha and beta calutron buildings eventually occupied an area greater than 20 football fields, and the entire electromagnetic separation facility grew to 268 buildings, requiring 20,000 workers to build.
This was an enormous undertaking in a relatively short amount of time, even during wartime. I can hardly fathom the scale and urgency of these operations. I suppose the Russians invested similarly massive resources to build their own A-bomb after the war.
Interestingly, it was believed at the time that German scientists were also very close to producing a nuclear weapon. As was later discovered after the war, there were not.