The Manhattan Project

Darragh Nagle's Interview

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Darragh Nagle

Darragh Nagle graduated from Columbia University and worked with Enrico Fermi and Herbert Anderson at the Chicago Pile during the early years of the Manhattan Project. Nagle then transferred to Los Alamos, where he joined the Omega Team and conducted criticality experiments. Nagle was also responsible for collecting soil samples after the atomic bomb test at the Trinity Site. Nagle discusses his friendship with Joan Hinton, one of the few female scientists at Los Alamos, and also shares stories about some of the other famous scientists who worked on the Manhattan project.
Date of Interview: 
August 2003
Location of the Interview: 
Santa Fe

Darragh Nagle: Well, you must realize you’re talking to the people who were very, very junior at the time of the Manhattan Project. We’re mostly the ones that are left, but by that same token we were not privy to the high council—what was going on. 

My time started in Chicago. I had been a graduate student at Columbia University and there I met as my teachers Enrico Fermi and the Mayers [Maria Goeppert Mayer and Joseph Edward Mayer] and Harold Urey and all those people—they were my teachers. And a somewhat younger person was Herbert Anderson, whom I knew much, much better, we were pretty good friends. Herb was Enrico Fermi’s principle assistant at that time, so he and Fermi did experiments in the buildings around the campus there, Pupin Laboratory especially but also Schermerhorn was another. And so it was actually Anderson who recruited me to come to Chicago and work on the project there, and that I did after having been at graduate school—several years at Columbia. 

Well Chicago was the scene of intense activity of course. I worked at the very end at the chain-reacting pile, but shortly after I came it was decided to move it to Argonne. And so after making a few measurements with the Chicago Pile, it was torn down and moved to Argonne. So all of that activity was literally underground because the Manhattan Project occupied the basements of all the buildings on campus, and the students were walking around going to classes on the upper floors, and it looked pretty much like a normal place.  

The West Stands was where the pile was. That was an interesting place—it was the old west stands of the football stadium. And it was built in gothic style; it had lots of ivy on the outside and it was very black, because there was a lot of smoke in Chicago then. All in all it was a very gloomy place from the outside. It looked like a good setting for a third-rate murder mystery or something. And inside it was even better because there were lots of people in overalls, absolutely black, and just red eyes shining out of these black faces. The black was graphite of course. And these were the people who were doing something—some job or other with the pile—and then later of course that was all moved to Argonne. 

So those were the Chicago days. There was a dormitory built at Palos Park. Many of the physicists would stay there quite often overnight; even Fermi would sometimes come out there. I learned that way Fermi suffered from insomnia, because in the middle of the night he would wake up, start writing something in his notebook, and after a while he would go back to bed. 

So we were out there in the woods of Palos Park, doing what seemed to be needed to be done. Finally our group, particularly Anderson and his associates, transferred to Los Alamos and we were there till the end of the war. Our laboratory in Los Alamos was the so-called Omega Building where the water boiler reactor was and where the critical assembly experiments were held, of which we’ve talked on other occasions. And all the buildings on the main Mesa have been destroyed now. Except Fuller Lodge still stands and a few of the old stone buildings plus Bathtub Row, so it all looks very different now.

Cindy Kelly: So were you involved with the work on the critical assembly?

Nagle: No. As I mentioned, I think to you once before, we were a little group that did experiments that Fermi wanted done, and these typically involved perhaps irradiating some samples in the reactor and then measuring the radioactivity that was produced. But whatever Fermi wanted done, we would do in the way of experiments. And as I mentioned, Fermi had a rule that when there was an experiment going on using a critical assembly or any part of that, we were told to stay out of the building. So we would either go up to the main Mesa, where we had some little cubbyhole that we could occupy, or we would just go for a hike. So we got to do some hiking that way. Course you could say it wasn’t very fair when other people were working hard, but orders were orders [chuckle].  

What else can I tell you about Los Alamos?

Kelly: Well, were you part of the Manhattan Project or the Metallurgical Laboratory team in Chicago? I mean, how much did you know about the Manhattan Project then? Were you recruited and working on this secret project as a graduate student in Chicago, or was it when you moved to Los Alamos?

Nagle: I don’t understand the question. Fermi was in charge of the pile. Herbert Anderson was his chief assistant. I worked for Herbert Anderson mostly and did whatever seemed to be required. These were mostly experiments that were done with the pile, and then later we had to tear it down, take it apart, and move it to Argonne.

Kelly: So were you one of these men with the black faces?

Nagle: Well I wasn’t machining graphite, so my face wasn’t as black as some.

Kelly: Were you actually a witness to the day it went critical?

Nagle: No, I wasn’t there that day.

Kelly: Did you hear reports about that day and how Fermi behaved or reacted?

Nagle: No, I’d come to Chicago a few weeks after that, so I wasn’t part of the team that put the pile together and brought it to criticality.

Kelly: Did you ever run into Leo Szilard?

Nagle: Yes.

Kelly: And what was he like?

Nagle: Well, again there is tremendous lore about Szilard. I didn’t have any close association with him so I just knew the stories. Later, after the war, in Chicago I knew him a little bit better. He became head of an institute for biological studies at the University of Chicago, which was physically next door to where I was working, at what is now called the Enrico Fermi Institute—used to be called the Institute for Nuclear Studies. So I don’t know anything firsthand about Leo Szilard, everything I know is just lore and stories and there are plenty of those.

Kelly: What about at Los Alamos, who were some of your fellow physicist that you worked with closely?

Nagle: Well the Omega team—the person who would design and supervise construction of the reactor was Percy King. And Percy stayed on at Los Alamos after the war. And Fermi’s order applied to King as well as everybody else so that when we went on hikes there would be King and some of the other people who worked there: Bill Starner, Joan Hinton, Bob Carter, myself, Herb Anderson, Julius Tabin, Fermi of course, those were some of the people.

Kelly: Right. What about Joan Hinton? Can you tell us what she was like? It was just unusual—it was unusual to have a woman scientist?

Nagle: I know a lot about Joan. Why do you want to know about her?

Kelly: Well I think she’s had a very interesting career and that we actually are trying to, you know, bring out more about the women who were at Los Alamos and other parts of the Manhattan Project, especially about the ones who had some roles on the sciences.

Nagle: Well other people I guess have written about Joan. I know quite a lot about Joan, we were good friends. Joan came from a very distinguished family of physicists and mathematicians. In her family tree is [George] Boole, the inventor of Boolean Algebra-- very famous person—and Sir G. I. [Geoffrey Ingram] Taylor, a very famous mathematical physicist. And her mother ran the Putney School in Putney, Vermont, which is a well-known school. And she had a sister and a brother. 

Joan studied physics at the University of Wisconsin and then she came to work with the team in Los Alamos; particularly, I knew her from the water boiler in Omega West, Omega time. Joan was an experimental physicist. She was a champion skier on the US Olympics squad so she was very rugged, sturdy girl. She’d also grown up in a farm-like setting at Putney School. She knew all about horses and cows and such like. And all of the Hinton family—I never met the father, so I cant tell you about him, but the rest of them were all quite left-leaning and quite critical all policies for the US government, especially after the war. Joan of course eventually went with her husband to Red China, you know all this?

Kelly: No. This is for the record.

Nagle: What?

Kelly: This is not just for my benefit, this is for this film so even if I know something—

Nagle: Oh I see. Well Joan had a very exciting time. She crossed through the battle lines between the two Chinese armies and went over to the Red Chinese side—suffered many hardships and privations during that time. They didn’t always have a lot to eat and they lived for a while in the caves in Western China, I guess, and she got quite sick at one point. She said the cure was to feed her lots and lots of millet, I don’t know why that was supposed to be good for her—anyway she got better. And Joan now runs a dairy farm outside of Beijing, which she does for her contribution to the Chinese people, I guess you would say. And she’s very upset that China has moved toward being a capitalist society; she thinks that’s terrible and [inaudible] of everything she thought, she and everybody else thought too. So she has very strong feelings about that. Her son was brought up in China but has moved back to the states, works here now. So that’s sort of what I know about Joan.

Kelly: Can you talk more about what her job was at Los Alamos?

Nagle: She was doing similar things to what we were doing: irradiating foil, building equipment that might be wanted.

Kelly: What about people from the British Mission? I understand that Fermi was grateful because many were experimental physicists and they were used to building a lot of things and that was very helpful to have many of them there. Did you have any observations?

Nagle: Well, Tiverton was one of the senior experimentalists and he did some of the electronics for the project. Jim Tuck [James L. Tuck] of course was a very well known personality and his contributions you can find in many places. Then there was Klaus Fuchs, who was part of the British delegation. And there was a couple of junior people, Hughes I remember, and Tony French. Tony French wound up as a professor of physics at MIT and Tony married one of the girls who was working at Los Alamos during the war. So that was the British delegation.

Kelly: Now, did you know Klaus Fuchs?

Nagle: No.

Kelly: No. Or did you know Ted Hall?

Nagle: Not very well. No.

Kelly: Did you feel that there was a lot of tension about the military censorship of mail and their restrictions and collaboration among the scientists? Was that a problem for you as a scientist?

Nagle: That wasn’t a problem for me. I felt we were at war, censorship was a natural thing, and it didn’t particularly bother me.

Kelly: Let’s see. Did you know the name Peer de Silva, who was sort of head of the military’s counterespionage group at Los Alamos?

Nagle: I think I’ve heard the name but don’t remember anything about him.

Kelly: Well what was it like living? Where did you live when you were there? You were a single man at the time?

Nagle: Yes. They had constructed a dormitory for the students—for the people in our category. If you were married, you might get a small Army hutment for you and your wife. If you were a big shot you could have maybe a house on Bathtub Row. Fermi, who was rather a democratic person, refused to take one and took one of the apartments instead. For a while we were living in some temporary quarters before they built this dorm for us. It’s since been converted to being a Unitarian church, and so where there used to be occasional parties there are now preschoolers occupying the floor—but I don’t think the preschoolers are quite as exclusive as some of the ones we’ve been reading about in New York City recently. So, again there’s no memorial plaque on that building saying that “Darragh Nagle lived there.” But in fact I don’t think most people realize it use to be a dorm.

Kelly: So were those open rows of bunks, or did you have your own room? 

Nagle: We had our own room. So you know in a way we realized we had a pretty easy life, because a lot of people had it tough. Here we were in a very nice location with many amenities that other people didn’t have. But occasionally the work was tough and dangerous, as we all know.

Kelly: Can you tell us about some of the tough times?

Nagle: Well we were involved in the preparations for the Trinity test, and our job was to collect soil samples from the crater as soon as possible after the explosion. And that involved fitting out a Sherman tank with lead shielding, and one of my jobs was to supervise the placement of the lead shielding. I was very interested in that because I knew I was going to have to ride in that tank and the lead shielding was what was going to keep my radioactive dose to something perhaps tolerable. 

So then we fitted out that tank and those that did ride into the crater—we took turns going in. Herbert Anderson went in first. Julius Tabin went in once, maybe twice. And I went in. Each of these trips was with one physicist running the sampling equipment. If you think of some delicate equipment, such as what you see in the science fiction movies, I assure you the sampling equipment was really more like a spade. We had left a little hole in the bottom of the tank—enough to get a spade in—and we put the spades down, pulled out a sample of dirt. So we did that.

The only one we didn’t allow to go in was Fermi; we couldn’t risk him in such a place. We knew that the Sherman tanks had a habit of stalling, so we wondered what would happen if the tank stalled in the crater. And we knew the answer. I mean, that would have been the end—there’s no way we could have gotten out. Fortunately none of the runs ended that way. However, there was a second tank that was fitted out with rockets and it did stall, I believe, fortunately quite a long way from the crater. The idea was to fire rockets from a distance. 

So that was perhaps the dangerous part and it was somewhat dangerous being round a place where critical experiments were being done. A little bit dangerous working with a pile in the early days, when people didn’t know all that much about piles. But we all survived; here we are many years later.

Kelly: What about your work schedule? How many days a week did you work? How long were your hours?

Nagle: Except for the Trinity test—

Cameraman: Let’s change tapes.

[Tape switch.]

Cameraman: Okay we’re back.  

Kelly: I don’t remember—we talked to somebody who wasn’t—

Nagle: Well it was a huge number of people.  Herman Turkevich, George Cowan.

Kelly: Oh, George Cowan.

Nagle: George Cowan.

Kelly: Okay, he’s got the tape on. Let’s see, you were going to tell me about how many hours a day you tended to work and how many days a week, and how it might have changed as you approached the Trinity test, that kind of thing.

Nagle: That’s right, as we got to the Trinity test we just worked as much as there was work to do. Actually it wasn’t a matter of midnight work for us—you don’t go digging samples in the middle of the night, we did that after the bomb went off. I don’t know how to say—

Putting together the pile was done on a very tight and urgent schedule. People worked very, very long and hard hours on that, but I came after that so I missed that. Putting together—reassembling the pile was mainly done by workmen and we worked on perhaps electronics and things like that. So I would not say all in all the people around me had particularly arduous backbreaking labor to do.

Kelly: Now what about time off? Did you say you had some forced hikes? Not forced hikes, but you had opportunities to hike when there were criticality experiments that Fermi didn’t want you to be near? Was there a whole lot of hiking, skiing over the years?

Nagle: Well this might be one or two days a week, yes, so there was a lot of hiking I’d have to say—might be half a day, a couple times a week while these experiments were going on.

Kelly: What other kinds of things did people do for entertainment or recreation?

Nagle: Well there was skiing. There was a little rope-tow on Sawyer’s Hill and people liked top go up there and ski on weekends. Occasionally hikes would be at places in New Mexico—not right on the Los Alamos site—so we got to see some of the wilderness of New Mexico.

Kelly: What about Santa Fe? How often did you get into Santa Fe?

Nagle: Well we would go in after hikes and occasionally we would have a meal at a restaurant. That was pretty much my experience for Santa Fe.

Kelly: Now was it hard to get transportation? Did you have a car?

Nagle: I did not have a car, some of my friends did. So that was the transportation, private automobile.

Cameraman: Want to talk about more technically.

Nagle: The technical work.

Cameraman: Yes a little bit more—because it was a big puzzle, lot of people knew just their section of it. Did you wonder about the rest of the project? Was there a lot of speculation, lot of rumors going around about what actually was being done, and you realizing that?

Nagle: Well I wasn’t concerned with the big picture and I was perfectly content to leave that to the likes of Fermi and Oppenheimer and E. O. Lawrence and Harold Urey. They didn’t need my advice nor did they seek it, so I didn’t worry much about those things. My feeling was there were other people in charge of that, and why should I bother? My contributions wouldn’t have been particularly useful or particularly appreciated, so I did what I was told [chuckle]. And if you were working for a person like Fermi that’s not so bad.

Cameraman: So was that pretty exciting? I mean at that stage in your career you were a young man to be working with a person like Enrico Fermi. That must have been a real thrill.

Nagle: Well we saw around Los Alamos, of course, all these famous people. When I went to Columbia as a graduate student there were all these distinguished people—Fermi, Urey, the Mayers, Nordsick, Rabi. Some of them had been born and bred—Herbert Anderson—some of these people had been brought up in America, but then there were people like Fermi and the Mayers, who were really distinguished scientists, who were there at Columbia because of circumstances of the war one way or the other. And then when we moved to Chicago there they all were again. And then when I moved to Los Alamos there they all were again, plus some other new eminences—Oppenheimer, and we saw Niels Bohr and other people around. But I saw them from afar; we weren’t really privy to their work. 

Joan was a good friend of the Oppenheimer family and so at one point Joan’s mother came out to Pecos and the Oppenheimers lent her the cottage on Grass Mountain, which is still there, I think. So I did get to visit the Oppenheimer cottage on Grass Mountain, and Joan and Mrs. Hinton were there. I think the building still stands and you see it as you go up Grass Mountain. For example, when we go to Ribe's cabin you pass it on the way there. I think it’s still there, unless the family may indeed have sold it, but I think the building is still there. 

And that’s a place of historical significance because that was where the Oppenheimer boys went to build up their health and Frank Oppenheimer said—he spent much time there. And his words were, “We rode all over the place from there,” and in fact they had ridden to Los Alamos and in a certain sense that’s how Robert Oppenheimer knew about the place. So it has a certain little place in the puzzle of the history of the project.

Kelly: Maybe we can preserve it. I hope so. Yeah, definitely.

Nagle: So if we go up to visit the Ribes sometime, take a look as you drive up the hill and look for the cottage.

Kelly: That’s great.

Cameraman: It’s a popular misconception—I don’t know if you saw that film, Little Man, Fat Boy, you know the one with Paul Newman—that there was this small cadre of physicists up there creating this project, but in reality there were thousands of people up there, weren’t there?

Nagle: In Los Alamos? Yes. Well it grew, I mean, it had started with an advanced guard—yes, there were thousands of people there.

Cameraman: So how would you explain what they were all doing up there if someone was to ask you, “Why did it require so many people?” People don’t realize the scope of the project I guess, isn’t that right?

Nagle: Today?

Cameraman: Yeah.

Nagle: Explain why?  Why it was hard?

Cameraman: Well, why was it—so many people necessary to create, you know, one weapon?

Nagle: Because the weapon was something that was completely different from anything that had ever been built before. It operated under—it had to have the fissionable material, it had to be of extreme purity. There were all kinds of problems. You had to be sure that there is not so much spontaneous fission that the thing would never assemble. The assembly method had never been worked out—that was done during the war—and involved a regime of a state of materials that had never been experienced before. And the way to achieve that had never been done; all these things were brand new. And the chemistry that had to be done—all these things were brand new. There was a whole technology of explosives, which was also brand new. So there were always people working on these different aspects. It was qualitatively different from building a larger cannon, I assure you. And that’s why you had people with very different disciplines all assembled at this one place way the hell out in New Mexico.

Cameraman: Was that a unique time? Could you recreate that?

Nagle: Could I recreate World War II?  Heavens no! I don’t think.

Cameraman: And you think that was the catalyst—because it was a confluence of minds that maybe, I don’t know, whether you could possibly get that many people to cooperate again. Was it unique in that respect?

Nagle: I’m not sure I understand your question.  

Cameraman: Brokaw wrote a book about World War II, The Greatest Generation, and it seems this was analogous to that. That as far as science goes, this was a unique opportunity to get this many great physics mind together. Was it?

Nagle: Well, yeah.

Cameraman: I just wondered if you could elaborate on that. In other words, I mean—is that possible again? Would it take a world war to bring that much scientific collaboration together?

Nagle: I don’t think history repeats itself. I don’t think anything like that will ever happen again.

Cameraman: I think you’re right. There’s a unique—do you have anything else, Cindy?

Kelly: You mentioned going up to Oppenheimer’s cabin, and well—you never mentioned working directly—with Oppenheimer directly.

Nagle: No, I didn’t.

Kelly: What credit would you give to [Oppenheimer] for the way things worked at Los Alamos?

Nagle: He was the director, he was the boss, he made all kinds of decisions, and my impression he ran the whole project with great skill and efficiency.

Kelly: One of the things that I think a lot of people don’t understand was that the success of the Manhattan Project wasn’t inevitable. You know, as a student of history you read the textbook, “Well of course we were successful in this,” you know, but that’s looking back at the time. To what extent do you think people felt confident that you would be able to make this weapon? 

Nagle: What people?

Kelly: What’s that?

Nagle: What people? 

Kelly: Well, yourself.  

Nagle: Oh, I myself thought, yes, it was going to happen. With that kind of talent you could hardly lose, you couldn’t miss.

Kelly: Enrico Fermi has a nickname, at least I’ve heard, called “The Pope.”

Nagle: Yes he was sometimes called “The Pope.”

Kelly: And why was that?

Nagle: Well he was considered to be infallible on questions of physics [chuckle].

Kelly: As someone who worked with him, did you think he was remarkable?

Nagle: Oh absolutely. Yes.

Kelly: Some people said that he was remarkable in that he was both a theoretical physicist, but had a very good sense of experimental physics.

Nagle: Well his theoretical work, which was outstanding, was done when he was quite a young man. And then—if you followed Fermi’s life—he sort of made a transition to experimental science when he was back in Rome. At the school of Rome, he was working on problems of irradiating all kinds of materials with neutrons. So they created a new science—a new nuclear science—Fermi led that for many, many years. And his part in designing and bringing the pile into being was a sort of a combination. But you could probably say by that time, Fermi had left the more abstruse kinds of quantum field theory that he had been an expert on once, was now interested in other things. 

After the war he even did a couple very nice pieces of theoretical physics—some very nice papers on the origin of cosmic rays and he was very interested in neutron diffraction. And he wrote a number of very important papers, both experimental and theoretical on this topic. So he continued as sort of a universal sort of physicist after the war until the last year, when he got very sick. But he has sort of been less interested in the more abstruse kinds of theoretical physics by that time.

Kelly: Now after the war, a lot of the top echelon scientists went back to their universities, some of them changed fields even. What about yourself and your colleagues, who were just graduate students you know before the war? How did the experience of the Manhattan Project shape the rest of your career?

Nagle: Well I went to MIT and finished my graduate studies and did a thesis there, and I was at MIT for about five or six years. I spent a year in Cambridge, England and then had the opportunity to go back to the University of Chicago and be a junior faculty member there. And when I got there, coming off from—back from Cambridge, England, it was really a surprise, because not only was Anderson there and Fermi there, which I knew, but all the others. The Mayers were there, and Urey, Leo Szilard, and all the people I’d known at my graduate days at Columbia were there again, it was same crowd. I say “crowd”—these were extraordinarily distinguished people and I felt tremendously honored to be able to work with them and be around them.

You know, in a way it was very funny because I left Columbia going to Chicago and there they all were. And then I went to Argonne and then to Los Alamos and there they all were again. I came back to Chicago and there they all were. So one tended to suffer from the illusion that that’s the way people were supposed to be, everybody was supposed to be that smart. Course they weren’t, but that was the impression you got. And it would have been nice if more of those smarts had rubbed off on me, but here we all are anyway.

Kelly: What about your colleagues that you know, were part of your team?  Have you kept up with any of them? Did they continue on in science also?

Nagle: Of my colleagues?

Kelly: Yeah.

Nagle: Well we talked about Joan and she’s over in Beijing. Julius Tabin is a close colleague of mine—we’ve kept up, he’s a patent lawyer in Chicago now.  Many of the people have retired now. Herb Anderson’s gone of course. Fermi’s gone. I attended a reunion in Chicago on the occasion of Fermi’s 100th birthday, which was the year 2001—August 2001 it turned out to be. And I saw a lot of the people I’d known before. So kept up, I do run into them from time to time, but sort of in a professional way. I see Julius Tabin from time to time—he’s remained a good friend of mine.

Kelly: How do you think that Manhattan Project changed American science?

Nagle: Well it changed American science because the government had been given proof positive that these people were capable of very large projects—carrying them out more or less on schedule and within costs. And they could be trusted to build what they said they wanted to build, and that led to a generation of very large accelerators in this country, for example. And that was possible because, I think, people in the government believed the physicists when they said they could do this somehow.

Kelly: Do you think the world of industry was a critical factor as well in the success of the Manhattan Project? Like the companies like Union Carbide, DuPont?

Nagle: Absolutely. Absolutely. They did what they were asked to do.

Kelly: Did you ever have any acquaintance or hear about Crawford Greenewalt?

Nagle: What?

Kelly: Know the name Crawford Greenewalt?

Nagle: Yes, I know who he is.

Kelly: We’re actually going to be doing a profile of him for Dupont and I just thought—

Nagle: I had no interaction with Greenewalt.

Kelly: He apparently was at Stagg Field on that December. 

Nagle: Yes, he knew all those people. I think he knew Herbert Anderson quite well, for example, but I didn’t know him.

Kelly: Some people have notions about whether we should have dropped the bomb or not dropped the bomb. Do you want to make a comment on that?

Nagle: Well as you know there was a large—a fairly large effort among the scientists who had worked on the project to not have the bomb dropped in anger but to have a demonstration, and Truman decided not to do that.

Kelly: So it was really not the scientists’ decision.

Nagle: It was absolutely not the scientists’ decision, and how the scientists would have voted if you’d had an election is not clear to me either. I mean certainly, some of the leading scientists like Ernest Lawrence—yeah, I would expect to be a rather hawkish person, but I was not a close associate of Lawrence in any way.

Kelly: What lessons or what—if you had your great-great-great-grand-child here—would you want to impart to that generation about the Manhattan Project? What do you think is an important lesson for future generations to learn?

Nagle: Well, I haven’t tended to think a lot about the societal questions of such a matter.