The Manhattan Project, the US program to build an atomic bomb during WWII, is one of the most famous and widely known major government projects: a survey in 1999 ranked the dropping of the atomic bomb as the top news story of the 20th century. Virtually everyone knows that the project built the bombs that were dropped on Hiroshima and Nagasaki. And most of us probably know that the bomb was built by some of the world’s best physicists, working under Robert Oppenheimer at Los Alamos in New Mexico. But the Manhattan Project was far more than just a science project: building the bombs required an enormous industrial effort of unprecedented scale and complexity. Enormous factory complexes were built using hundreds of millions of dollars worth of never-before-constructed equipment. Scores of new machines, analytical techniques, and methods of working with completely novel substances had to be invented. Materials which had never been produced at all, or only produced in tiny amounts, suddenly had to be manufactured in vast quantities.
Great detailed history! Always good to see the nuts and bolts exposed.
I think there's an interesting question here about causality in how we tell the Manhattan Project story.
The narrative here seems to follow the pattern:
Scientific discovery
→ Engineering application
→ Manhattan Project success.
But I wonder if the causality actually ran more like:
Urgent wartime need
→ Massive practical/economic work (uranium enrichment, metallurgy, explosives handling)
→ Scientific insights crystallised through that work.
Your account actually shows this—so much of the crucial knowledge emerged from the sustained industrial work itself. The calutron operators learning optimal procedures, the metallurgists figuring out plutonium's strange properties through daily handling, the explosives teams developing casting techniques through thousands of failed attempts. Or the months spent just figuring out how to prevent uranium slugs from corroding. Even the "xenon poisoning" discovery came from running reactors at scale, not from theory.
It reminds me of how the steam engine generated new science about thermodynamics, rather than being an application of existing thermodynamic theory. Similarly with the Wright Bros. The Manhattan Project's scientific insights seem to have crystallised through the massive practical work of making these processes function day after day, rather than being applied to that work.
This doesn't diminish the achievement—if anything, it makes it more impressive. But it might change how we think about replicating it. Instead of "assemble brilliant scientists then engineer their discoveries," maybe it's "create urgent practical work that pulls scientific insights into existence obliquely."
This project hired over 1 million people at various points. Those people were trained to become skilled technicians, engineers and managers. That trained cohort was directly responsible for American postwar prosperity. The post-WW2 economy through the 1980s would not have happened without the Manhattan Project.
For example, in a recording studio, there was always a guy who could field-strip a tape recorder or mixing console at 3am and make it better then before. Where did he learn? The Manhattan Project.
I believe it! Gramps was a Chem E, drafted into the Navy kicking and screaming in '44, and was made a radioman on a destroyer. They sat off the Philippines for 6 months, saw no action, and then it was all over.
WW2 was when the US military got serious about analytics of their operations, and training the hell out of everyone. Until then I think they followed the British model of "officers just know what to do because they are men of breeding, and enlisted men are scum, and nobody needs any real training".
I read a good book on this some years back. It was in my company library and told a good story. There was sort of a skunk works feel about the program.
I think there's also a good illustration here about one reason that things take so long to build now compared to "back in the day." You mention the products of the processing canyons at Hanford:
"The end products would be radioactive wastes, stored on site in underground tanks, and small quantities of highly purified plutonium nitrate."
When they were building the canyons, they new that they'd end up with radioactive acid at the end of it, and they didn't know what to do with it. They said, "We're going to put it in tanks and let the US Government figure out what to do with it after the war is over."
We are still working on what we are going to do with it, 81 years later. The radioactive waste from that first batch of slugs in 1944 is still in tanks at the Hanford site. (Well, some of it might have leaked out into the groundwater.) The plan is to use a vitrification process that might finally start in a couple weeks, after 23 years of construction.
Nowadays, we'd require them to know what they were going to do with it before starting. There are obviously tradeoffs in construction time from that approach. Stuff like this doesn't explain everything, but I think it's one contributor.
Reading this account, I am struck by the paradoxes required to make the Manhattan project possible. Many smart people with the freedom to produce innovative ideas were required. Yet, the scale of the project required the creation of a bureaucracy to manage it that would inevitably choke of that freedom to innovate.
The bureaucracy was choking off freedom to innovate, even during the Manhattan Project itself, and this was done by design.
Now, this is mostly from reading Leslie Groves' memoir, so it needs to be taken with a grain of salt, both because it could be self-serving, and because it was written 20 years after the fact. But it does seem consistent with how things were run.
Groves' goals for the management of the project were to sharply limit anything not *strictly* bomb-related. Security was the biggest reason, of course, but economy was a close second. His general philosophy was (paraphrasing), "I have been given unlimited budget and authority solely for the purpose of producing an atomic bomb, and allowing that to be used for even tangential research which doesn't advance that goal is an abuse of that power and a betrayal of the US taxpayer."
To quote him directly:
"Compartmentalization of knowledge, to me, was the very heart of security. My rule was simple and not capable of misinterpretation—each man should know everything be needed to know to do his job and nothing else. Adherence to this rule not only provided an adequate measure of security, but it greatly improved over-all efficiency by making our people stick to their knitting. And it made quite clear to all concerned that the project existed to produce a specific end product—not to enable individuals to satisfy their curiosity and to increase their scientific knowledge."
Groves, General Leslie R.. Now It Can Be Told (Franklin D. Roosevelt and the Era of the New Deal) (p. 140). Hachette Books. Kindle Edition.
Victoreen instrument company was physically closed down by the government because nobody had security clearance. On a different General and asked why the volume of test instruments was not being produced Victorern shows him the other Generals paperwork on shutting it down do to security. After the two generals got together finally figured out they had to get everybody in the company security clearance victoreen also had to call in all of ham radio operators because they built their own equipment they knew how to solder and Built a production line to finish up the radioactive telemetry equipment for the bikini bomb blast I'm barely got it to the dock on time for the test all the equipment worked.
Did that bureaucracy really choke off the freedom to innovate? The Manhattan Project had numerous spin offs and devolved into numerous research laboratories that continued to innovate. There has been a lot of innovative stuff out of ORNL, LBL, LANL among others.
Given that these laboratories are STILL major sources of innovation, you'll have to support that statement somehow.
Corporate labs, of course, often stifle innovation when it isn't seen as aligning with corporate goals. That's why Pfizer dropped GLP-1 in the 1990s even after it demonstrated its effectiveness as a weight loss drug. The corporate goal was delivering insulin without needles. Vertex almost dropped Kalydeco, a cystic fibrosis drug, in favor of a hepatitis drug that lost out in the marketplace. The suits running things have their own business goals and their own resource limits.
Government funded labs run into different restrictions. Spending is usually constrained by political considerations. Try developing a more advanced mRNA product these days. Still, they offer a lot more freedom since there is no direct need to make a profit. Most of them have funding for internal R&D.
The Manhattan Project had almost unlimited resources with the government commandeering the economy to fight the war, but government research labs are still a great place to explore new science and technology.
Has anyone done a cost-benefit analysis of whether it would have been better to produce more conventional weapons rather than the A bomb? The Tokyo firebombing was pretty effective. The scale of the buildings required for A bomb production would have been pretty obvious to the Allies in WW2.
Invading Japan was going to be a nightmare, and it wasn't likely that better conventional weapons would have shortened the war. Remember, in the spring of 1945, one raid on Tokyo killed 200,000 people, twice the number killed in Hiroshima and Nagasaki combined, but the war went on. The invasion of Okinawa gave a foretaste with every battle a fight to the last man and civilians committing mass suicide. If you get a Purple Heart medal nowadays, there's a good chance it was manufactured for the million expected US casualties in the upcoming invasion of Japan.
It wasn't that the atomic bombs killed more people or destroyed more stuff that led Japan to surrender. It was the sheer shock at the almost supernatural level of destruction each bomb wrought that gave the Japanese high command permission to surrender. There's a good book on this, Unconditional.
To add to Kalebergs excellent summary below you’ve kinda missed the origin of development which was before the outbreak of WWII and before anyone knew how Japans role in the war after Pearl Harbour would play out.
The race to develop the bomb was not with the intent to drop on Japan.
So at the point that its (bombs) use on Japan was an option the development costs had been expended.
What, no mention of Lise Meitner. If you grab the front page of the New York Times reporting that Hiroshima bomb, there's an article on her: "Reich Exile Emerges as Heroine In Denial to Nazis of Atom's Secret". Back then journalists knew a good story.
Really interesting to learn about more of the details of the complexity involved.
One question I have - did they actually manage to do this without any serious injuries or fatalities due to accidents with explosives, or radiation spills?
There certainly were accidental deaths as a result of the Manhattan Project. One source I found lists 14 deaths at Los Alamos during the war itself; most were construction or transportation accidents but there was also a fall from a horse, a suicide, a negligent firearm discharge, and a boating accident. The earliest death of a Manhattan Project employee I could find that was due to the specifics of the project was Harry Daghlian, who was exposed to radiation a week after the end of the war and died about a month later. Other Americans who died from acute radiation poisoning in the following years include Louis Slotin, Cecil Kelly, Robert Peabody, Richard McKinley, John Byrnes, and Richard Legg. If you expand that to include greater incidences of cancer among Manhattan Project employees or cancer and birth defects among civilians the number grows but it's hard to say by how much; estimates are in the hundreds of thousands or maybe even millions globally. And of course some hundreds of thousands of people were either killed immediately or suffered a reduced lifespan as a result of the bombings of Hiroshima and Nagasaki.
Fantastic! And much shorter than "The Making of the Atomic Bomb."
What I find interesting is that, from what I've read, the B-29 project, overall, was even more expensive. And it set the stage for commercial aviation as we came to know it.
"The Manhattan Project required an unusually large amount of this (advancing the state of the art in many different disciplines), but will always be required to some degree."
Dr John A Victoreen , help develop the rare earth coating for the filament tubes anodes,the help lower the power on the filaments to make the tubes last longer. Also produced high quality scales for the personal dosimeters. He got his Doctorite on the publication on the Elemental atomic absorption coefficients to the 10th place by hand. He had to wait for the long tables to come be published and years later they had a computer recalculate his figures and only two or off or incorrect turn out that they log tables or the part that was incorrect.
There was a problem with the geiger counter sensors burning out under high dose radiation. Victoreen came up with the magnetic vein switch internally in it tube with timing of this switch prevented the tube from burning out they were able to measure radiation on the order of 10 times of what a normal tube could do. Years later a government vignette company videotaped a conversation with him and there was a lawsuit with the government as to the scale not having a danger line on his equipment, his answer to that was he didn't do it,it wasn't up to him to determine what was dangerous it was only up to him to be accurate on the readings. That was more of a medical regulation to be determined by somebody else. He is not being a medical doctor.
1) Proliferation of Nuclear Technology around the world.... and the means used to limit its proliferation
2) Nuclear technology has gained mythical status.... yet there is a line of thought that all the predictions of nuclear winter are bogus... in fact conventional volcanic eruptions have more power then all the nuclear arsenals in the world.... don't know if any of this is true, but it would be worthwhile to explore.
Great write-up with lots of interesting details that I hadn't know even though I've read a lot of material on the topic.
For years I've highly recommended Rhodes' "The Making of the Atomic Bomb" (which you reference) and his follow-up book "Dark Sun: The Making of the Hydrogen Bomb". They're very well written (the first won a Pulitzer prize) and covers the scientific, political, engineering, and military aspects of the story in an integrated way. Two things I learned from the first and which you highlight in your writeup have stuck with me for years: (1) they had the money, tenacity, and skills to develop not one, but _two_ independent paths to the bomb (uranium- and plutonium-based), and (2) they were so confident in the uranium bomb that they didn't even test it before using it in the war. (Your write-up informed me that there were actually many cases where multiple paths were explored.)
The first book has a great side story about a system for capturing the plutonium if the Trinity test failed--i.e., to deal with the case where the high explosives would simply scatter the plutonium core around the test site. The system was built at great expense but not actually used for the test.
Great detailed history! Always good to see the nuts and bolts exposed.
I think there's an interesting question here about causality in how we tell the Manhattan Project story.
The narrative here seems to follow the pattern:
Scientific discovery
→ Engineering application
→ Manhattan Project success.
But I wonder if the causality actually ran more like:
Urgent wartime need
→ Massive practical/economic work (uranium enrichment, metallurgy, explosives handling)
→ Scientific insights crystallised through that work.
Your account actually shows this—so much of the crucial knowledge emerged from the sustained industrial work itself. The calutron operators learning optimal procedures, the metallurgists figuring out plutonium's strange properties through daily handling, the explosives teams developing casting techniques through thousands of failed attempts. Or the months spent just figuring out how to prevent uranium slugs from corroding. Even the "xenon poisoning" discovery came from running reactors at scale, not from theory.
It reminds me of how the steam engine generated new science about thermodynamics, rather than being an application of existing thermodynamic theory. Similarly with the Wright Bros. The Manhattan Project's scientific insights seem to have crystallised through the massive practical work of making these processes function day after day, rather than being applied to that work.
This doesn't diminish the achievement—if anything, it makes it more impressive. But it might change how we think about replicating it. Instead of "assemble brilliant scientists then engineer their discoveries," maybe it's "create urgent practical work that pulls scientific insights into existence obliquely."
Curious what you think about that framing?
This project hired over 1 million people at various points. Those people were trained to become skilled technicians, engineers and managers. That trained cohort was directly responsible for American postwar prosperity. The post-WW2 economy through the 1980s would not have happened without the Manhattan Project.
For example, in a recording studio, there was always a guy who could field-strip a tape recorder or mixing console at 3am and make it better then before. Where did he learn? The Manhattan Project.
It wasn't just the Manhattan Project. For a long time, every lab technician in the country seemed to have been in the Signal Corps during the war.
I believe it! Gramps was a Chem E, drafted into the Navy kicking and screaming in '44, and was made a radioman on a destroyer. They sat off the Philippines for 6 months, saw no action, and then it was all over.
WW2 was when the US military got serious about analytics of their operations, and training the hell out of everyone. Until then I think they followed the British model of "officers just know what to do because they are men of breeding, and enlisted men are scum, and nobody needs any real training".
Wonderful! Makes SpaceX look cautious.
A nice follow-up might be the development of nuclear power led by Admiral Rickover, which was both for peaceful and military machines.
I read a good book on this some years back. It was in my company library and told a good story. There was sort of a skunk works feel about the program.
I think there's also a good illustration here about one reason that things take so long to build now compared to "back in the day." You mention the products of the processing canyons at Hanford:
"The end products would be radioactive wastes, stored on site in underground tanks, and small quantities of highly purified plutonium nitrate."
When they were building the canyons, they new that they'd end up with radioactive acid at the end of it, and they didn't know what to do with it. They said, "We're going to put it in tanks and let the US Government figure out what to do with it after the war is over."
We are still working on what we are going to do with it, 81 years later. The radioactive waste from that first batch of slugs in 1944 is still in tanks at the Hanford site. (Well, some of it might have leaked out into the groundwater.) The plan is to use a vitrification process that might finally start in a couple weeks, after 23 years of construction.
Nowadays, we'd require them to know what they were going to do with it before starting. There are obviously tradeoffs in construction time from that approach. Stuff like this doesn't explain everything, but I think it's one contributor.
Reading this account, I am struck by the paradoxes required to make the Manhattan project possible. Many smart people with the freedom to produce innovative ideas were required. Yet, the scale of the project required the creation of a bureaucracy to manage it that would inevitably choke of that freedom to innovate.
The bureaucracy was choking off freedom to innovate, even during the Manhattan Project itself, and this was done by design.
Now, this is mostly from reading Leslie Groves' memoir, so it needs to be taken with a grain of salt, both because it could be self-serving, and because it was written 20 years after the fact. But it does seem consistent with how things were run.
Groves' goals for the management of the project were to sharply limit anything not *strictly* bomb-related. Security was the biggest reason, of course, but economy was a close second. His general philosophy was (paraphrasing), "I have been given unlimited budget and authority solely for the purpose of producing an atomic bomb, and allowing that to be used for even tangential research which doesn't advance that goal is an abuse of that power and a betrayal of the US taxpayer."
To quote him directly:
"Compartmentalization of knowledge, to me, was the very heart of security. My rule was simple and not capable of misinterpretation—each man should know everything be needed to know to do his job and nothing else. Adherence to this rule not only provided an adequate measure of security, but it greatly improved over-all efficiency by making our people stick to their knitting. And it made quite clear to all concerned that the project existed to produce a specific end product—not to enable individuals to satisfy their curiosity and to increase their scientific knowledge."
Groves, General Leslie R.. Now It Can Be Told (Franklin D. Roosevelt and the Era of the New Deal) (p. 140). Hachette Books. Kindle Edition.
Victoreen instrument company was physically closed down by the government because nobody had security clearance. On a different General and asked why the volume of test instruments was not being produced Victorern shows him the other Generals paperwork on shutting it down do to security. After the two generals got together finally figured out they had to get everybody in the company security clearance victoreen also had to call in all of ham radio operators because they built their own equipment they knew how to solder and Built a production line to finish up the radioactive telemetry equipment for the bikini bomb blast I'm barely got it to the dock on time for the test all the equipment worked.
Did that bureaucracy really choke off the freedom to innovate? The Manhattan Project had numerous spin offs and devolved into numerous research laboratories that continued to innovate. There has been a lot of innovative stuff out of ORNL, LBL, LANL among others.
> Did that bureaucracy really choke off the freedom to innovate?
By now it largely has.
Given that these laboratories are STILL major sources of innovation, you'll have to support that statement somehow.
Corporate labs, of course, often stifle innovation when it isn't seen as aligning with corporate goals. That's why Pfizer dropped GLP-1 in the 1990s even after it demonstrated its effectiveness as a weight loss drug. The corporate goal was delivering insulin without needles. Vertex almost dropped Kalydeco, a cystic fibrosis drug, in favor of a hepatitis drug that lost out in the marketplace. The suits running things have their own business goals and their own resource limits.
Government funded labs run into different restrictions. Spending is usually constrained by political considerations. Try developing a more advanced mRNA product these days. Still, they offer a lot more freedom since there is no direct need to make a profit. Most of them have funding for internal R&D.
The Manhattan Project had almost unlimited resources with the government commandeering the economy to fight the war, but government research labs are still a great place to explore new science and technology.
Has anyone done a cost-benefit analysis of whether it would have been better to produce more conventional weapons rather than the A bomb? The Tokyo firebombing was pretty effective. The scale of the buildings required for A bomb production would have been pretty obvious to the Allies in WW2.
Invading Japan was going to be a nightmare, and it wasn't likely that better conventional weapons would have shortened the war. Remember, in the spring of 1945, one raid on Tokyo killed 200,000 people, twice the number killed in Hiroshima and Nagasaki combined, but the war went on. The invasion of Okinawa gave a foretaste with every battle a fight to the last man and civilians committing mass suicide. If you get a Purple Heart medal nowadays, there's a good chance it was manufactured for the million expected US casualties in the upcoming invasion of Japan.
It wasn't that the atomic bombs killed more people or destroyed more stuff that led Japan to surrender. It was the sheer shock at the almost supernatural level of destruction each bomb wrought that gave the Japanese high command permission to surrender. There's a good book on this, Unconditional.
To add to Kalebergs excellent summary below you’ve kinda missed the origin of development which was before the outbreak of WWII and before anyone knew how Japans role in the war after Pearl Harbour would play out.
The race to develop the bomb was not with the intent to drop on Japan.
So at the point that its (bombs) use on Japan was an option the development costs had been expended.
What, no mention of Lise Meitner. If you grab the front page of the New York Times reporting that Hiroshima bomb, there's an article on her: "Reich Exile Emerges as Heroine In Denial to Nazis of Atom's Secret". Back then journalists knew a good story.
Really interesting to learn about more of the details of the complexity involved.
One question I have - did they actually manage to do this without any serious injuries or fatalities due to accidents with explosives, or radiation spills?
There certainly were accidental deaths as a result of the Manhattan Project. One source I found lists 14 deaths at Los Alamos during the war itself; most were construction or transportation accidents but there was also a fall from a horse, a suicide, a negligent firearm discharge, and a boating accident. The earliest death of a Manhattan Project employee I could find that was due to the specifics of the project was Harry Daghlian, who was exposed to radiation a week after the end of the war and died about a month later. Other Americans who died from acute radiation poisoning in the following years include Louis Slotin, Cecil Kelly, Robert Peabody, Richard McKinley, John Byrnes, and Richard Legg. If you expand that to include greater incidences of cancer among Manhattan Project employees or cancer and birth defects among civilians the number grows but it's hard to say by how much; estimates are in the hundreds of thousands or maybe even millions globally. And of course some hundreds of thousands of people were either killed immediately or suffered a reduced lifespan as a result of the bombings of Hiroshima and Nagasaki.
Fantastic! And much shorter than "The Making of the Atomic Bomb."
What I find interesting is that, from what I've read, the B-29 project, overall, was even more expensive. And it set the stage for commercial aviation as we came to know it.
"The Manhattan Project required an unusually large amount of this (advancing the state of the art in many different disciplines), but will always be required to some degree."
-> "IT will always be required."
Dr John A Victoreen , help develop the rare earth coating for the filament tubes anodes,the help lower the power on the filaments to make the tubes last longer. Also produced high quality scales for the personal dosimeters. He got his Doctorite on the publication on the Elemental atomic absorption coefficients to the 10th place by hand. He had to wait for the long tables to come be published and years later they had a computer recalculate his figures and only two or off or incorrect turn out that they log tables or the part that was incorrect.
There was a problem with the geiger counter sensors burning out under high dose radiation. Victoreen came up with the magnetic vein switch internally in it tube with timing of this switch prevented the tube from burning out they were able to measure radiation on the order of 10 times of what a normal tube could do. Years later a government vignette company videotaped a conversation with him and there was a lawsuit with the government as to the scale not having a danger line on his equipment, his answer to that was he didn't do it,it wasn't up to him to determine what was dangerous it was only up to him to be accurate on the readings. That was more of a medical regulation to be determined by somebody else. He is not being a medical doctor.
Awesome ! Great Work...
May I suggest two followups.....
1) Proliferation of Nuclear Technology around the world.... and the means used to limit its proliferation
2) Nuclear technology has gained mythical status.... yet there is a line of thought that all the predictions of nuclear winter are bogus... in fact conventional volcanic eruptions have more power then all the nuclear arsenals in the world.... don't know if any of this is true, but it would be worthwhile to explore.
Existen realmente las bombas atómicas? Fueron realmente lanzadas?
Great write-up with lots of interesting details that I hadn't know even though I've read a lot of material on the topic.
For years I've highly recommended Rhodes' "The Making of the Atomic Bomb" (which you reference) and his follow-up book "Dark Sun: The Making of the Hydrogen Bomb". They're very well written (the first won a Pulitzer prize) and covers the scientific, political, engineering, and military aspects of the story in an integrated way. Two things I learned from the first and which you highlight in your writeup have stuck with me for years: (1) they had the money, tenacity, and skills to develop not one, but _two_ independent paths to the bomb (uranium- and plutonium-based), and (2) they were so confident in the uranium bomb that they didn't even test it before using it in the war. (Your write-up informed me that there were actually many cases where multiple paths were explored.)
The first book has a great side story about a system for capturing the plutonium if the Trinity test failed--i.e., to deal with the case where the high explosives would simply scatter the plutonium core around the test site. The system was built at great expense but not actually used for the test.
Brilliant