An engineering history of the Manhattan Project
construction-physics.com154 points by rbanffy 2 days ago
154 points by rbanffy 2 days ago
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.
The Rhodes book is great on this. Fermi was such a good physicist and a great hands-on engineer. Before electronic calculators or computers: a slide-rule, graphing paper and a notebook. A lot of danger getting the maths wrong! Luckily, Fermi was very good at maths.
I have in my possession a chunk of one of those graphite bricks. Very neat piece of history.
> but after 28 minutes, the alarm bells went off to notify everyone that the neutron flux had passed the preset safety level
Really feels like catching the dragon by its tail.
Imagine the fallout (literally and figuratively) if they'd gotten the calculations wrong.
Was there ever a radiation hazard from that or a big cleanup? Seems very "early days safety standards".
That reactor was run at a very low power level, so there was little activity. It was dismantled in 1943 and the parts moved to make CP-2 near Chicago at a site that later became Argonne National Laboratory. CP-2 had shielding (but no cooling) and operated at a few kilowatts.
> 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
Groves's book ("Now It Can Be Told") mentions the people that worked with the graphite bricks, that it got into their skin, and even after an after-work shower, they'd still ooze graphite for hours.
Firstly I wonder what their cover story for their spouses was.
Secondly it's clear that they should've had an on-site sauna. Get some deep cleaning going. That would've flushed the graphite gunk out of their hides.
When the USSR was building the bomb, the director of the graphite manufacturing company unofficially asked Kurchatov (the lead scientist of the Soviet nuclear project) to bring him a handful of diamonds.
He assumed that graphite of such high purity can be useful only for this purpose during the wartime.
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.
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.
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.
> Biographies of the preeminent scientists of the 20th century
This was the only parts of the book I skimmed over / skipped. While interesting, many of them go back to their parents and childhood upbringing which, again are interesting, but being more interested in the science/engineering I would skip ahead until their story was more relevant.
> The Making of the Atomic Bomb Book by Richard Rhodes
A good book.
May I also recommend the In Our Time episode on the Manhattan Project.
https://www.bbc.co.uk/programmes/m00108h1
(The Richard Rhodes book is on the recommended reading list for this episode, listed on the linked website; as are other very good books on the Manhattan Project worth a read).
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.
I read and enjoyed The Making of the Atomic Bomb and Dark Sun, but another book by Rhodes made me question his veracity. <https://www.goodreads.com/review/show/4413437417>
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.
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.
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...
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.
Soviets also benefited a lot from German scientists pulled from post-WW2 Germany in their own version of a Paperclip-like program. Recommended reading: Forgotten Creators by Todd Rider. Free and online, over 4,000 pages including references and important appendices, so one has to navigate to the chapter / section of interest.
This is the same Todd Rider whose PhD work at MIT (advised by the late Lawrence Lidsky) showed aneutronic fusion was unlikely to be workable. Lidsky had previously argued DT fusion wasn't going to cut it because of inherently low volumetric power density and had argued aneutronic fusion should be pursued. Between those two approaches lies lower neutronicity D-3He fusion, which may be fusion's only real hope. Helion has the lead in pursuing this approach, with a design focusing on highly efficient energy recirculation that feels informed by Rider's analysis.
His analysis of German fusion advances during WW2 is very much present in his work.
Learned about that book from HN, so thanks HN. Of late, I've been reading The Alchemy of Air which revolves around Haber-Bosch process and it's been a delight so far. Highly recommend if you love a mix of non-fiction, history & science.
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, they were not.
> it was believed at the time that German scientists were also very close to producing a nuclear weapon.
Yes this was the prime motivator, at least on paper. One can suspect Vannevar Bush or Leslie Groves of ulterior motives (Vannevar: fomenting a defense-fueled ‘Big Science’ infrastructure which he certainly achieved going into the postwar, Groves: creating a weapon to fend off the Soviets for the postwar).
> As was later discovered after the war, there were not.
Man this is a dicy one. There has been some scholarship in recent decades that the Germans may have got a lot farther than history has hitherto accepted to date, all the way up to minor (semi-fizzled?) detonations. Rainer Karlsch has been the main accumulator of relevant archives especially from the Soviet side. Todd Rider formerly of MIT’s Lincoln Lab has done yeoman’s work in piecing together the logic of Karlsch’a work and archive digging of his own & volunteers’. In short, we are not sitting on a consensus reality of just how far the Germans got in developing an atomic bomb, and we aren’t 100% certain on how little we relied on recuped German know-how in developing our own atomic bomb between May-August 1945, not how much we (ahem, Teller) may have relied in part on German know-how in developing the H-bomb. As I mentioned in another comment, the reference for this is
https://riderinstitute.org/revolutionary-innovation/#chapter...
Appendix D is the main one for this topic, and Chapter 8 for context.
The Soviet and other later nuclear weapons programs were significantly less expensive/complicated to reach equivalent capabilities, because they didn't pursue several paths simultaneously like the Manhattan Project did. They also weren't so rushed.
For example, the USSR built plutonium production facilities and tested a working plutonium-based implosion bomb before they produced highly enriched uranium. The Soviet uranium enrichment program was also simplified compared to the US: they built out the most effective technology that the American program demonstrated (gaseous diffusion). They developed the marginally effective calutron enrichment process only to a trial scale and ignored the practically useless liquid thermal diffusion enrichment process.
China choose two paths as well[0], and while at it building the largest man made tunnel complex in the world[1].
[0] https://nsri.nebraska.edu/-/media/projects/nsri/docs/academi... [1] https://en.m.wikipedia.org/wiki/816_Nuclear_Military_Plant
True, but I would note the Soviets chose to do things like put nuclear reactors and Pu production complexes underground to protect them from American air strikes. The sheer scale of their efforts and the added requirements for things like undergrounding entire plants certainly pushed their spending sky-high.
Yes, both countries' nuclear weapons programs were extraordinarily expensive over time. The first underground reactor of the Mining and Chemical Combine was built in 1958, well after the USSR had started stockpiling fission and fusion weapons. The original Mayak production complex had ordinary above-ground reactors.
I believe that the the "AD", "ADE-1", and "ADE-2" reactors here are the only underground ones:
https://en.wikipedia.org/wiki/Soviet_atomic_bomb_project#Plu...
They also had the benefit of having stolen information on what did and didn't work, via spies like the Rosenbergs. Why try what doesn't work if someone else has proved the path before
The USSR (first bomb test: 1949) obtained secret American information from spies and the UK (first bomb test: 1952) had secret information that was intentionally shared by the US. France (first bomb test: 1960) is an interesting case because it developed its program relatively frugally without intentional US information sharing or (as far as I know) spies within the US nuclear weapons program. By the late 1950s there was just a lot more information publicly known that couldn't be hidden again. And today there is nuclear information readily available on Wikipedia that would have been considered top secret as recently as the 1970s, like:
https://en.wikipedia.org/wiki/History_of_the_Teller%E2%80%93...
> They also weren't so rushed.
The threat to the US was that, unless they are first to develop nuclear weapons, they’d risk the war could end up being fought on their land.
I've always assumed that gaseous diffusion required a process similar to silicon etching in order to achieve the pinhole sizes required.
> It reached the US, ...
Behind that phrase is a whole story in itself, covered in the book "Wizards of Oz How Oliphant and Florey helped win the war and shape the modern world" by Brett Mason.
Mark Oliphant was heading a lab and tasked Otto Frisch and Rodolf Perierls with figuring out whether an atomic bomb was possible, as they were not cleared to work on radar. They concluded it was possible and wrote a two part memorandum: 'On the Construction of a "Super bomb"; based on a Nuclear Chain Reaction in Uranium' and 'Memorandum on the Properties of a Radioactive "Super-bomb"' [1,2]
Oliphant sent this report up the chain and it lead to the formation of the MAUD committee in the UK. The UK didn't have the resources to build an atomic bomb, so what was known was sent to the US. Oliphant hopped on a plane and did a tour of the US, doing technology transfer, mainly for radar, but also for an atomic bomb. Most people in the US ignored the MAUD report and Oliphant could not get traction on the atomic side. In desperation Oliphant breached security and briefed Ernest Lawrence who at the time was not cleared, also providing him with a summary of the MAUD report. Robert Oppenheimer joined the discussion between Oliphant and Lawrence. Lawrence phoned Arthur Compton in Chicago. From there the USA listened.
[1] https://web.stanford.edu/class/history5n/FPmemo.pdf
[2] https://en.wikipedia.org/wiki/Frisch%E2%80%93Peierls_memoran...
It's amusing to think about what the technical hiring process would have been like if it were to happen now.
"Need 10+ years of experience in nuclear detonation device."
This article claims the B-29 bomber cost more to develop than the atomic bomb. Wild to think that the atomic bombe is simpler than an airplane.
https://www.bbc.com/future/article/20250829-the-bomber-that-...
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
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!
Ah, someone read Now it Can Be Told, (1962) by Gen. Leslie Groves, head of the Manhattan Project. This is the classic, and I read it as a kid. Much was still classified then, and we now know some things in there were wrong.
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.
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/
Thank you for the link. I tried using their little search table, but nothing returned. One thing that makes matters a bit more difficult was record keeping at the time. My family has some other documents from his life where he apparently went by a few different permutations of his name. That, or mistakes were made when entering records.
I might trying contacting them directly though. Thanks again!
If you want advice on archives, you should just write to one of the historians who are experts on the Manhattan Project. The preeminent expert on nuclear weapons history is Alex Wellerstein, who also has a very well-regarded blog that comes up on HN from time to time: https://blog.nuclearsecrecy.com/
My great-grandfather was part the team who selected the site for Oak Ridge (the only civilian, together with four military men - he was the TVA's chief mechanical engineer at the time), and he also selected the separation method to be used. The town of Oak Ridge even named a day after him when he retired.
>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?
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 bugbear, IMO.
When I was there a few years back there was a room there full of file cabinets you could indeed peruse.
This part stands on its own and applies to everything, as well-learned lessons that felt instinctively & universally American to anyone born in the decade after the war:
>Because the field was so new, using only recently-discovered natural phenomena that were poorly understood, a great deal of effort was needed to resolve this uncertainty along numerous technological axes. Thus the Manhattan Project involved a large amount of trial and error experimentation, and of pursuing multiple paths of technological development —
>It’s this last difficulty that is most relevant for other technological development projects. Developing other technologies doesn’t necessarily require building enormous, industrial scale industrial facilities to even begin, and doesn’t necessarily require rapidly proceeding before the proper information and supporting technologies are available. But it will almost certainly require investigating various promising paths of development, partially-informed groping around until the right combination of methods and components is discovered. Indeed, this sort of exploration is the very essence of technological development.
>resolving this uncertainty, and figuring out what a technology should actually be, is hard. The Manhattan Project had some of the most brilliant scientific minds in the world working on it, but even with this collective brainpower it was far from clear what the best route to the bomb was.
>Not all technologies will require expensive physical facilities to produce, or require extremely rapid, expensive development. But resolving the uncertainty inherent in a new technology — figuring out what, exactly, the arrangement of phenomena needs to be to achieve some goal, and how that arrangement can be achieved — is part of the fundamental nature of creating a new technology.
Never thought this kind of approach would be allowed to fade so far from what it once was. Almost nobody is even trying to carry the torch any more.
Question: are there any other known "Manhattan projects" and if not, why not?
Yes, although not at that scale.
- Several products from the Lockheed Skunk Works, including the U-2 and SR-71 reconnaissance aircraft and the early stealth aircraft.
- Russian titanium submarines
- The original US spy satellites, the CORONA program.
- At the moment, China building aircraft carriers. They're built in shipyards that also build container ships, and it's hard to tell from the air which hulls are military.
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.
Moon landing was done in full view of the public while the Manhattan project was a total secret. Based on that, I don't think they are the same.
One could suggest the development of the B2 Stealth bomber would be closer than NASA. The design of satellites used by NRO are much more secret than NASA.
I mean very simply: a highly secretive project that explores new physics for some radical new, destructive technology.
It's interesting that everyone here is talking about mundane technologies or technologies that stem from a project that is almost 100 years old.
What happened to physics? We just found the one interesting thing and that was it?
Evidently the development of the B29 bomber (one of which carried the Hiroshima/Nagasaki bombs) cost more than the Manhattan project. https://en.wikipedia.org/wiki/Boeing_B-29_Superfortress
>Question: are there any other known "Manhattan projects" and if not, why not?
Answering this question is necessarily an exercise in 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. As Congressional hearings leading to just this past Tuesday’s, Sep 9th have amply demonstrated, there increasingly appears to be some veracity to these claims. https://m.youtube.com/watch?v=LBKRr5OvF6E&t=1056
Podcast/narrated version would be cool.