The Manhattan Project

Robert Cantrell's Interview

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Bob Cantrell's Interview

Robert Cantrell joined the Manhattan Project in 1943 and worked as an architect for Dr. Walter Zinn’s design group at the University of Chicago. Working from his office in Ryerson Hall, Cantrell helped design a new mechanism for inserting the control rods into the nuclear reactor. He also designed innovative tools for scientists who were working on radioactive materials. Cantrell recalls borrowing a peace of platinum from the New Chem building at Chicago and being reprimanded walking back to his office without an armed escort; he found out that the piece of platinum was worth “about seventy thousand dollars” and that he “had about half of all the available platinum in the country.” After the war, Cantrell continued his career as an architect and helped design buildings for universities across the country.
Manhattan Project Location(s): 
Date of Interview: 
June 26, 2013
Location of the Interview: 
Mesa
Transcript: 

Cindy Kelly: Okay I am Cindy Kelly, Atomic Heritage Foundation and we are in Mesa, Arizona on June 26, 2013 and with me is Robert or Bob Cantrell. And the first question I have for him is to tell me his name and spell it.

Bob Cantrell: My name as I remember it is Robert Cantrell, R-O-B-E-R-T C-A-N-T-R-E-L-L.

Kelly: And Robert, what year were you born or what was your birth date and where were you born?

Cantrell: I was born January 27, 1921 in Gainesville Texas.

Kelly: And then tell us a little bit—I think it is nice to let you just describe without my interrupting to play 20 questions—if you could talk for a little bit about what your boyhood was like, where you went to school, how you got interested in or how you came to be part of the Manhattan Project?

Cantrell: Well I went to school in Wichita Falls, Texas, and I graduated from high school there and I also graduated from Junior College down there. I had a little practice going designing houses for people; they were simple track houses and that sort of thing. Then the war came along in December of 1941 and just cut that off like it was a knife cutting a piece of cake. And there was not more of that so I got a job working for some big architectural firms out in West Texas and New Mexico and even over here in Phoenix, to produce plans for airfields and that sort of thing. 

Well after about a year and a half, they did not need that anymore so I decided I would try to go up to Chicago and see what was there for me to do. I wanted to contribute something to the war effort so I decided to try my luck in Chicago. I did not know anything, of course, about the Manhattan Project at that point. I went to work for an outfit called Universal Oil Products and we were designing oil refineries and that sort of thing and I was just a draftsman, you have to understand I was a young man back in those days. 

There was another fellow there by the name of Julius Lavin and he and I became good friends. Julius introduced me to the symphony and all kinds of things but some friend of his was working down at the University of Chicago and he talked Julius into going down there to go to work. So Julius, after he went down for about two weeks, he called me up and said, “Hey Bob, I think there is something down here that might be of interest for you.” 

And I said, “Well I do not know,” this is kind of boring. I did not want to work on bloody old refineries, but that too was part of the war effort, this was for the island of [inaudible]. But anyway I went down and was interviewed by a fellow by the name of Wally Holmes who was in charge of the design department at the Electrical Lab there in I think it was Ryerson Hall. Wally thought that I might be suitable for their purposes and so he said, “Well okay I can offer you a job.” And I do not remember what the salary was but it was not much like in comparison for today but it was about what an engineer would get or something. And here I was, this draftsman. 

So to make a long story short I left the Universal Oil Products and went down there and went to work in Ryerson Hall for Wally’s group, drafting and design group for support for all of the scientific personnel, the physicists, chemists and all those kinds of people that needed anything. And what you have to know is there was a little shop out in back of Ryerson Hall called the Ryerson Annex and they had all these people who were excellent model makers and machinists and that sort of thing from the Museum of Science and Industry over there. 

By now the Manhattan Project had been going for a couple years—I think it started out in ‘39. Anyway, this was in November of ’43. The first sustained chain reaction that occurred in the west stands December 2, 1942. That is when Enrico Fermi and Leo Szilard and Dr. [Walter] Zinn—there must have been twenty-five or thirty people involved in that. 

Then they decided they had better not monkey around with fissionable materials anymore in a populous area so they moved it out to Lamont, which was then called the Argonne National Preserve. And so they moved out there and they wanted to reassemble it. So when I came onboard in ’43—this was about a year later after the first sustained reaction—they had reassembled this whole thing out there. Their first reactor they tore it down completely; it was an old graphite-moderated reactor as I am sure you know. 

So Dr. Zinn one day instead of putting in the control rods—you know in order to accelerate the activity within a reactor you have to let the neutrons first of all be slowed down so they will cause fission and that is what the graphite was all about. And then secondly if you want to accelerate that well you pull out some cadmium rods that absorb excess neutrons or you push them in if you want them to absorb the neutrons. So he came by and Wally decided that I ought to give him what he needed in the way of a design drawing for this idea of having automated control rod drives. Well I had never heard of a control rod drive, I had never heard of a reactor, I had never heard of a pile or any of that stuff, so I kept asking Dr. Zinn. 

He said, “Well I cannot tell you too much but I can tell you this much, we need to have this cadmium rod go in and out.” And it was about two inches in diameter or so, I do not remember the exactly. But the idea was it would go down and telescope in and out and then it would swing back and forth like a pendulum all at the same time. The speed of the thing was to be manipulated by an operator so they would make it go faster or slower, like an accelerator in a car almost; you make it go faster, you make it go slower or you can put the brakes on and slam the rod all the way home, which is what they did in the first one by the way but there was not anyone to stop it but they did it by hand. And after a while with all the gamma radiation and that sort of stuff you do not do that by hand very often or hardly at all.

Anyway, that was a very complicated project and I worked very closely with the guys in the shop. We were up on the third floor I think it was of Ryerson Hall; I had a nice big old window that I could look down on the little shop. I could not see what was going on in there of course and it was really quite an idyllic setting to spend your time doing design work and that sort of thing. But we had to pull out all we could pull out in the way of gear catalogs and motor catalogs, and work out the ratios and everything because he wanted to reverse it to go in and out as well as swing back and forth so we had to figure out how to do all that stuff. So my job was to make the drawing for all that and that was one of the first jobs that I had down there and it was pretty complicated thing. 

Well anyway to make a long story short, after a few months we got it all built—as a matter of a fact we built two of them—and they took it out to Argonne. Of course, nobody would tell you whether it works or whether it does not work, they just say, “Well thanks a lot, fellow,” and you go on your way. 

Well I hung around there in Ryerson Hall for the better part of six to eight months. And then they tore up the old tennis courts that were over on Ellis and Engelside between 56th and 57th and they built some ugly old barracks buildings in there. But that was to be the new camp where they were going to separate out plutonium from U238. You know that plutonium is manufactured from U238, which is quite plentiful compared to the U235, which is fissionable. U238 is not [fissionable] but you can make plutonium out of it which is fissionable and that has an atomic number of I think 239 I believe. 

Well anyway the point of it was this stuff was very toxic and very dangerous, it puts out very heavy gamma rays so we had to work with lead shields all around any little bits and pieces that were generated in the reactor you see. Then they had to figure out chemically how to separate it out so they took the space over in the west stands where the original reactor was built and they built what they called a plutonium column over there. And again my job was to make drawings for all the little sample containers that they wanted to put stuff in and whatever equipment they wanted. Most of that column, by the way, was built out of glass. And we had a glass blower guy, he did not need any drawing, he knew how to do it and the scientific guys worked directly with him. Then Dr. Seaborg came on to oversee all of these scientific efforts and we of course were the support staff for him. 

Well also over there at New Chem, in addition to this plutonium column that we had to make bits and pieces and equipment for and getting samples made out of lead shields and lead had to be about three inches thick, we had a problem in the laboratory of how to protect the people form radiation that were actually working with this stuff. And they had a lead sink, the bottom of which would be maybe of above their heads about yay high and the top of which would be maybe two feet higher and with a mirror setup at about a forty-five degree angle. They could look up and see the sample they have got something to do and again the gamma rays were shooting out the roof, nobody cared about that. But this lead sink was made out of lead about three inches thick. Now the question got to be how could they slice it, dice it, titrate it, drill it, and do whatever they wanted to do in the lab? They could see it but how in the world are you going to handle it? You do not dare stick your hand in there because you would end up dying, and nobody wants to do that. 

So anyway, my job was to try and help get these things done. Sometimes these guys would bring coat hangers from home and they would manufacture all sorts of things and we would try in our little shop over there at New Chem, try to help them out as much as we could. I would make drawings and we would try all kinds of things. I remember as a kid we had erector sets and you made model cranes and that sort of thing. And then we had flexible shafts if they wanted to drill something you could drill it. 

Back in those days they did not have reversible motors and we did not have any of that stuff. We just had plain old motors go one way and that was it. So if they wanted to drill something in and pull something out well we had to figure out ways to do that, again up, over, and down through you see. And that was an interesting bunch of stuff to try to figure out, all these things that these guys wanted to do. They wanted to do little laboratory processes that you do with stuff but here you’re talking about all the terrible radioactive stuff.

So I worked over there until gosh it must have been the war was almost over and then a guy came up from Los Alamos and wanted me to go out there. I said, “Well what am I going to do?”

And he said, “I cannot tell you.”

And I said, “Well look, I just got engaged and I want to be able to come back and get married and spend some time with my wife and maybe she could come out there.” 

He said, “No, you cannot do it.” He said, “Once you go you have to stay.”

I said, “Well I am not so sure I want to do that.” And I said, “Well, can she come down there and we get married down there?” 

And he said, “No, no place to stay.”

I said, “Well, I do not think we are getting very far here.” 

And he said, “Well then we have work for you to do down there if you want to come down. 

I said, “How long do I have stay?” 

And he said, “Until the end of the war.” And this was in May of ‘45 and of course the war in Germany was just about all finished, but the war in Japan was not finished yet.

He said, “Well that is the way it is, take it or leave it.” 

And I said, “Well I think I will leave it.” 

So I never did go to Los Alamos. I do not know what they had in mind and of course nobody ever told me I suppose. But then they sent back what I thought was a actual part of the bomb because they wanted us to get some plating done and that sort of stuff, and it looked like a ladies hair dryer thing. It was about the size of a basketball about yay big around, with places for fuel slugs to go in and different places because there is such a thing called critical mass and if you get whole bunches of uranium or plutonium together it will blow up in your face and it would ruin your whole morning probably. But they had these things and it was sitting there and they did not tell me what they wanted done but they told the shop guy and he went out and got some plating done for them and that sort of thing and shipped it and gave it back to whoever was transporting things back and forth. 

So we got involved in a little bit of what I thought was the actual bomb but I do not really know. I worked mostly on getting equipment and material and machinery done for these guys that were doing the basic research at the University of Chicago. And then of course they built the reactors out at Hanford for production and they built the gaseous diffusion chambers down in Oak Ridge, Tennessee where they made the uranium and they tried to separate it out. Now days they use centrifuges, you know, to do it but back then they thought gaseous diffusion was very good. As far as I know, they still do gaseous diffusions, I do not think so though. Anyway that is what I did at the University of Chicago.

Kelly: Seems like you had fun.

Cantrell: Oh well it was interesting, it was interesting and I enjoyed the creative aspects of it you see. Drafting can be drudgery but this was creative kind of work and I enjoyed it very much.

Kelly: Well that is one of the themes of the Manhattan Project is how innovative—taken as a whole—the project was, it is just on the cutting edge and all these little things.

Cantrell: You see you could not fall back on experience because nobody had any experience. And there is no such thing as “This is the way we did it two months ago or two years ago or twenty years ago” because they did not have any. And of course everybody was scared stiff of Lise Meitner and the guy she was working with over there, Frisch or something like that—well in Germany whatever.

Kelly: Otto Frisch.

Cantrell: Frisch I think it was yes, they were working on a heavy water reactor and they even had a plant up on Norway you know where they were getting heavy water. And they were refining it and they were going to bring that down to the moderator where we used graphite over here for our moderator and everybody was scared stiff that they were going to beat us out and then Hitler—we would all be speaking German instead of English maybe. It did not happen of course, but there was this sense of urgency as well as the ability to be creative about doing something. 

Nobody came right out and said we are going to build a bomb; I think they called it T Metal. I think it was worded, T Metal—we were going to put together a bunch of T Metal and that is why they called it Metal Electrical Laboratory. I remember one cleaning lady said, “What are you folks doing over there?” 

And I said, “Well I cannot say.”

She said, “I heard you were doing vitamins.” 

And I said “Well yes, that is a pretty good idea,” And we just let it go at that. 

Anyway it was so secret that they really did not let you know much more than you could pop. They let you know the minimum amount so you could actually do your work but not anymore than that you see. And they discouraged you even from talking amongst yourselves, which is a dumb way to get anything done, but it got done anyway. And there were a lot of people that did a lot of work and a lot of dead ends were made. 

I know DuPont was involved in the early beginnings and I think Electric Boat Company was involved. They started out having industry and then I guess this guy General Groves got involved and he sort of then decided well maybe we ought to let the scientific guys setup the methods of how these things can actually happen before we start trying to manufacture something that we do not know what the heck we are manufacturing. So that was out job was to set this up and get the processes down and then after that then they could go ahead and make the big boomers.

Kelly: Going back to the project you had under Walter Zinn with the lead kind of sink above peoples’ head—you were trying to design something that could be operated remotely basically using the mirrors. Do you know and can you describe what you came up with?

Cantrell: Oh so many different things. We had little pumps to do the titration and that sort of thing, little laboratory pumps. To handle the product or the samples in the containers with the lead shielding around them were quite heavy as you can imagine. We had little monorails back and forth—the thing with a chain like they do in repair shops—you can lift it up and you can move it over and drop it back down again. So they were kind of basic to get things in and out of the sink and to do what they wanted to do in there as I said earlier. We had things with flexible shafts inside of a casing—metal wrapped casings—and then you could stir things or drill things and do that sort of stuff. You could also rig up little saws; they had little miniature saws that we could cut metal. Now a days you have what they call servo mechanisms I think they call them and you can stick your hand in here and you can do this and the servo mechanism was there and you can turn your hand like that and do like that. We did not have any of that. We just had mechanical things. 

It is hard to describe because each guy wanted to do something a little bit different with the sample that he was working on. So we just kept working and working and sometimes as I say the scientist guys themselves—because they were not dummies you understand, the university did not hire dummies all that much. So they would come up with something and say hey, scratch it out on a piece of paper, “Can you build this for me? And we would figure out a way to get it built. 

Sometimes they would come and say, “Hey, I want to do this, can you make me a design for it?” And we would try and make them a design. As I alluded earlier we had erector set kind of things—well they were not erector sets but that kind of thing—which we would put together with a motor and what not. But it was hard to get up and around the corner and back down again to do everything, move things back and for the and put them out in titration dishes and that sort of thing.

Kelly: Well it is interesting because I have been many times to the B Reactor or to Hanford and the chemical separation plant there had a series of baths and they had a monorail above the entire, they called it a canyon and they had operators on the third floor that used these new gadgets with mirrors and remote. But it was marvelous. It may have been patterned after the work you were doing.

Cantrell: Well we were sort of like a Henry Ford to a modern day automobile you know. A Henry Ford was simple and easy to fix with a pair of pliers and some baiting wire and that is kind of what we were doing. Or like the Wright Brothers flying their airplane compared to a jet airplane; it is all together different, it is a different process, it is a different mindset that you bring to it and all that. But I think the big difference was that we just tried to do things mechanically because that is all we had. We did not have anything electronically or anything else to work with back then in the 1940s, there was not anything. That is all we had. 

Nowadays of course they can do marvelous things just with the computer even—setup a program in the computer and let the computer do the work for you. We did not have any computers, we had slide rules. Even calculations with a slide rule is not very accurate, I mean it does not get you down to the details you need to have to refine some of these things. But anyway that was interesting. 

There was one incident I wanted to tell you about. One day one of the chemists brought me over a piece of platinum about ten inches square and he wanted to have a little container made out of the platinum. It was maybe ten inches square or something so I was forever writing out passes and taking things from New Chem, which is about two blocks away from the Ryerson shops. So I wrote out a pass and said I am taking this platinum over there to have something done with it and on the way over I stopped and I had a cup of coffee and a piece of pie because I did not have any breakfast that morning. And the total it was stamped out in one place and stamped in at another place was twenty-two minutes or so. 

Well about two days later my boss called me in and said, “Hey Bob, did you take a piece of platinum from New Chem over to Ryerson Hall?” 

And I said, “Yeah.” 

He said, “Do you know how much that platinum is worth?”

And I said, “I do not know what it is worth.” 

He said, “Well it is about seventy thousand dollars.” And he said, “You had about half of all the available platinum in the country.” 

And I said, “Well, I did not know, nobody tells you anything you just go and do whatever needs doing.” 

And he said, “How come it took you so long? 

And I said, “Because I stopped and had a cup of coffee and a piece of pie at this little shop down there at 57th street.” 

He said, “You had a piece of pie and some coffee while you were carrying around all this platinum?”

I said, “Yeah.”

He said, “You should not have done that.” I thought I was going to get fired right on the spot for breach of security or jeopardizing the war effort all together or whatever. 

He said, “Do not do that anymore.” He said, “We have guards and they will give you a ride over.”

And I said, “But it is only two blocks.” 

He said, “I do not care, you make sure you have plenty of guards on your way back.”

So I went over a couple of weeks later and the guy finished off with the container that we had to make and I had some platinum leftover and so I brought the whole thing back and gave it to the chemist but this time I had to have guards and got a ride in a car and the whole thing. Two lousy blocks but anyway that is the way we did it. That was one of the things that was fun. 

It was interesting working with all these great minds. I did not get a chance to know Enrico Fermi or Leo Szilard or Niels Bohr or any of those people; I would have loved to have known them. I did get to know Dr. Zinn pretty good. But afterwards I wanted to get back into architecture so I went to work for an outfit called [inaudible]. First I worked for a couple of the other larger firms and got my license in 1948. Then I went to work for an outfit called Shaw [inaudible]. Al Shaw knew a fellow by the name of Cunningham who was a business manager for the University of Chicago. And Cunningham had called Shaw and said, “Hey, we are running this Argonne National Laboratory out here.” Now this was after I had left the project, this was in 1952 I think maybe, and they wanted to build a reactor building. So Shaw came out, one of the prime partners in the firm I was working with, and wanted to know if anybody had any experience. 

And I said, “Yes I did.”

And he said, “Tell me about it.” So I told him about the control rod drives and all the other monkey business and the fact that I worked on it.

And he said “You are just the guy we need, we have a project for you.” 

So it turned out that the project was they wanted to build a reactor building, an experimental reactor building and they called it CP5, Chicago Power 5, and primarily they wanted to run material through the reactor itself to make isotopes for medical reasons and tracer reasons and all kinds of things. 

Later on then I understand that the CP5 effort got it built and used it for training other people as to how to run reactors and it got commissioned I think in ’54. They managed to mess it all up and they had to decommission it in ‘79 because well it was experimental and when you are doing experiments you do not know how things are going to turn out and I guess some things did not turn out too well. Anyway they had to tear the whole thing down. I understood it cost them about twenty times what the original cost was to tear it down then it cost us to build it in the first place. 

But let me tell you what was interesting about that, all the reactors that had been built up until that time were built in rectangular buildings and this one part of the requirement was that it be a containment building in case they have an accident or something like that it could contain all of the radioactive bodies within the structure itself. We did not quite know how to do that except that I got to thinking about it one night at home. You know how you wake up in the middle of the night and you think some good thoughts every once in a while and by golly they would make this thing round because that way the stresses will not come to the corners and cause a lot of cracks and that sort of thing. So we did, we made it round and then we had to figure out a way to detail all the doors and the openings and that sort of thing—gasketed materials and the doors opened and shut including the cams like they have on bank vaults so it really makes a good seal. 

But then we wanted to seal the building from atmospheric pressures. For example if it is sealed at a time of high pressure you have high pressure outside and inside if they have an accident to seal the building. Well that is fine except if a low pressure comes by two weeks later, and now there is high pressure inside the building that wants to go out, so how did we solve that problem? We got from the oil fields somebody—and this was in a meeting with Dr. Zinn and some of these other people out there in Argonne—somebody said, “Why don’t you get a Horton Dome?”

A Horton Dome has got a diaphragm inside of it that in effect changes the volume of the building that contains the pressure you see. So we got a Horton Dome and put it outside and connected it with a big old pipe about eighteen inches in diameter or so and that solved the problem of what to do about atmospheric pressure differentials. But then we had to figure out a way to get the people out if all the doors were shut and locked tight and they were inside and an accident occurred. So we had stairwells that go down like an inverted pig sty but with a wall down the middle and then they would flood those pigsties with water and okay guys we have to go down the stairs and go underneath the pigsty and back up on the other side again so the pressure differentials would maintain the seal while all these differentials were going on you see. 

So anyway that was kind of interesting and well of course we had to so something about spent fuel rods so we drilled holes just outside the sealed part of the building. We put holes in the ground with a pipe about yay big around and went down about maybe eight or ten feet I guess. And again sort of like the overhead rails, we put the spent rods down there. 

Nowadays they put them in what they call pools or something. I do not know why we did not put it in pools, it would have worked just as good as putting them in the ground, but we put them in the ground anyway. I do not know what they ever did with the spent fuel rods, one of those things nobody tells you; I do not think anybody really wants to know what to do with it. As I understand it they have not figured it out yet, spent a whole bunch of money on that place out in Nevada and Harry Reid said, “Nothing doing. As long as I am Senator you are not going to put any spent atomic energy waste out here.” So what? So you just spent forty million dollars or billion—I do not know a whole bunch. 

Anyway, that is really the end of my experience with any of the nuclear stuff. That was in ’55. Again, that was a fun project. I have had a lot of nice projects to work on.

I Went over to Spain in 1954 to ‘57 and we built out in caves in three different locations over there places to store actual completed A Bombs, again nobody says anything about it. But we did anyway.

Kelly: You went over there to—?

Cantrell: I was Chief Architect for the Air Bases in Spain. We built air bases in four different places: a big Naval air station down in Rota, down in the southeast corner of Spain, pipeline all the way across Spain, plus aircraft warning stations all over the place out there. Again everybody thought the Russians were going to take aver the world you know. Turns out that they did not have anything, just mostly bluffs. But we had a lot of money and so we spent it.

Kelly: Why do we not go back to the pigsties because I think these inventions are very interesting? Can you describe it again?

Cantrell: Well let me see if I can describe it. What we did was we built stairs going down like stairs going down in your basement, down to a flat place, and another stairway coming up. And we built a wall down here in the middle that came down below the level of the floor about two feet. So then we had a big old pipe about six or eight inches in diameter that would fill that whole thing full of with water. So now the water is level on both sides. The high-pressure area over here pushes it down on this side and of course it just floods and just runs out on the floor or whatever. But the guy has to go down and underneath this wall, you see, to get out if you swim through the water; we presume all these guys knew how to swim. So we had two of those.

Kelly: Oh my goodness, I see they do not just walk down the staircase they swim—

Cantrell: Well they want to get out in a hurry and that is why we had such big pipes to fill in this small space. The stairway was only about three or four feet wide; all we wanted to do was get a human body out or three bodies or five bodies or however were going to be monkeying around that day with the reactor. But nobody ever told me if they ever used them. I know they did flood them a couple of times because we watched that when we were testing the building, but I had never seen anybody actually use them.

Kelly: Well that is a good thing.

Cantrell: Yeah well we presume, I do not know if they had any accidents. We tested the building and when we tested the building before we turned it over to Argonne Labs and sure enough we did have a leak in it someplace. It turned out that one of the drainpipes in the basement floor somebody had forgotten to put a seal on it and we specific seals. We finally found that and put the seal in it and it worked okay. 

One other thing I wanted to point out was on this resource reactor, which I think they still do today because they do not build reactors much anymore, not even for generating electricity. We had a three-foot thick floor between the basement or the lower level and the upper level where all the work was done and where the reactor was sitting. That housed all the pumps for the chilled water as well as for the heat exchangers and all that sort of stuff and it was quite radioactive. We had to build that three-foot thick floor not out of concrete but out of concrete made out of steel punchings because it was heavy. Steel is a lot heavier than just plain old concrete. 

So we had the aggregate in there and of course we used cement to make the matrix. And the poor workers, when they first started trying to work it they tried to push a wheel barrel full of it and they could not push it, it was too heavy. So they only pushed about a third of a wheel barrel full at a time and they had to make this whole big old thick floor. And again it was to absorb all the gamma rays that might come from down below. So even after we left the Manhattan Project there were innovative things that needed to done. I do not know if they used some of those techniques in later reactors or not, again nobody tells you anything. They wanted to keep you dumb I guess.

Kelly: What about Walter Zinn?

Cantrell: Walter Zinn was a part of the original group that did the number one graphite-moderated reactor underneath the West stands [at the University of Chicago]. Later on he became the Director of the Argonne National Laboratories. He was a rather tallish kind of a fellow, good-looking fellow, very nice, and very calm; I never did see him get mad at anybody about anything. I worked with him a little bit on that first control rod thing because it was his idea as to what to do. And he kept coming back a couple times and said,  “Well gee if you would make this a little different here and a little different there,” of course like you would with any client, why you would accommodate him as much as you could. 

Later on when it came time to do the CP5 reactor building out there, by then he was the Director of the place. And we sat in on several meetings with him and his staff. Of course by then he had a big staff. I think that was before the actual Atomic Energy Commission was begun because my recollection is that he was in charge of the lab—still operated by the University of Chicago of course—but he was in charge of it before there was an Atomic Energy Commission. Then they came on and they put up a new level of security for us. 

Another interesting thing they made us do while we were designing that CP5 thing again back in 1953 or so. As soon as the Atomic Energy Commission people got in they decided that we were not secure enough in our architectural office down in the Chicago’s Loop, so they made us get a space to one side where everybody working on that project had to sign in and we had to get special passwords and we had to have locks on the doors and locks on the windows and I do not know what else. So we did we had combination locks on the file cabinets and the whole nine yards.

Guess what? After it came time to bid—they decided they would have competitive bids—so we set our plans out on the street for everybody to bid on it [chuckle]—all the plumbing, all the electric, everything, crazy. Well anyway, that was the Atomic Energy Commission for you. 

But Dr. Zinn was very practical and very easy guy to work with. He was a real gentleman, nice fellow. I cannot say that we became good friends or anything like that but he was our client. I had worked with this fellow named John West as I recall who was an engineer out there at CP5.

Kelly: That is great. I just know Walter Zinn because I worked on the experimental Breeder reactor 1 that he oversaw which was built in Idaho.

Cantrell: Yes, they had Idaho Proving Grounds they called it out there. I never did know quite what was going on out there.

Kelly: Secret.

Cantrell: Yeah I know everything was secret, I do not think we have secrets anymore though.

Kelly: I want to capture as much as I can about Chicago and the buildings there. So you talked about Ryerson.

Cantrell: There was another building right next door to it called Eckert and all the officers were over there; I think that is where Fermi and all those people had their offices in Eckert Hall. If you get out a map of it at the University of Chicago you will see that the two of them are right together. And the little annex out back, I do not know is that still there do you know? I have not been back to Chicago in so many years that I do not know but that is where we had our shop. 

So we had a little foundry down there and at the foundry we had nice milling machines and lathes and drill presses and these guys from the Museum of Science and Industry were used to making all these working models and all that sort of stuff. They were marvelous and they contributed to the design process too. It was not just a one-way street; it was back and forth all the time the way things would work out. 

Over in the Washington Park they had an old armory over there that they used as a warehouse and the purchasing was over there and if we wanted to purchase something like a new set of drills or whatever you would have to go over there and place your order for whatever you wanted. And sometimes they would have stuff in stock and they would lust give it to you. But often times if you wanted something special, they would work through all of the expediting, getting the necessary clearances, and getting the necessary priorities to get you your material or the tool or whatever it was that you were looking for. 

There was another group at the University working over on 61st and Woodlawn I think it was. I am not sure. They were working on the slugs, the actual fuel slugs that would go into the bomb. I do not know, five, six, ten, eight, however many it takes and they were working on how to handle those and how to open them and how to fill them and generally work on them. That was in an old separate industrial building over there that somebody was not using anymore. There must have been fifteen or twenty guys working over there.

Kelly: You mean the fuel slugs that go into the reactor?

Cantrell: Yeah. The fuel slugs were about yay big around and about eight, ten inches long.

Kelly: You said bombs so I was—

Cantrell: Well I think in the bombs not in the reactor, those fuel slugs, the fuel rods in the reactor of course were thin plates that go up and down and they can come in bundles. What else do you want to know?

Kelly: Well where did you live?

Cantrell: Oh boy that is interesting. I lived in an apartment nearby. My mother had come up from Texas and she went back and I went to live over on 5608 Marilyn which is two blocks away from where I worked in New Chem. And I met a young lady over there. She and her sister lived in the front bedroom and they had always rented out the back room to medical students because the University Hospital is right nearby there. And they always rented it out but the back room became vacant and one of the fellows that I worked with—a guy named Barry Pool—had been living over there and he went into the Navy and he told me, “I am vacating this room, you might like to check into it” because he knew I was looking for a place. 

And sure enough I went over there and I think they charged four dollars a week or something like that, it was not much. I met my first wife there because she was part of the family. She and her sister lived up on the second floor, the typical row houses that they have there in Chicago. She and her sister slept in the front bedroom, I slept in the back bedroom and her parents in the middle bedroom and they only had one bath for the whole works of us there in the middle upstairs. One thing lead to another and the next thing you know I am combing her hair and doing all kinds of nice things for her. Well you know how these old matches go, and that is when the guy came up from Los Alamos and wanted me to go there and I told him, “Nothing doing.” I did not want to go I wanted to get married instead and he said, “Well we do not do that sort of thing down there.” That is where I lived.

Kelly: Get your priorities straight.

Cantrell: Well I think so because it turned out well, we had a beautiful romance for forty-four years or whatever and she died of multiple sclerosis finally but that is another story. Anyway we had a nice life and the University of Chicago was interesting, and I got there almost by accident but yet somehow there was a magnet that got me there. Jules Levin was my friend and he said, “Hey Bob come on down, you might like this.” And sure enough I did and it only took two years out of my life or something like that, well less than two years. It was good in the sense that it teaches you how to think out of the box and that was wonderful. But I did not want to do that stuff, I wanted to be an architect so I did. So I got my license in ‘48 and did not look back, what else.

Kelly: All right, lets see, do you think that your architecture was incorporated in some of this thinking out of the box, were you influenced later on in your career?

Cantrell: Well yes I think so because I learned not only there but going to the Institute of Design there in Chicago, I learned how to think not about how do you do things in the past but what is the problem? What are the resources available? What is the time available? All these kinds of things, you set those things up rather than to say I want to just do something similar to what this guy did over there, that guy did over there. So yes in certain instances it was innovative. Up on the wall over there are some pictures of some of the buildings that I worked on later on. 

Yes, I believe the experience at the University of Chicago did teach you have to be creative and at the same time being practical. It is easy to be creative and just create a sculpture, it does not have to do anything, but a piece of architecture has to something, house somebody, allow something to happen, it has to have some kind of a function you know. So the same way down at the University there, eventually something had to function, took an awful lot of effort to get it to function but when you are doing something brand new, brand new materials, brand new techniques, brand new ideas, brand new concepts, it is tough sometimes to thing about.

Kelly: Well you mentioned earlier that the secrecy that everybody was sworn to made it kind of awkward and because you were not allowed to collaborate as freely as you might of or how would you express that in your own words?

Cantrell: Well I found out since that the best solution to any given problem is to get as many people working on it as you can and get them to understand what it is you are trying to achieve. What is your goal? What are you trying to do here? They really could not even see what the goal was, they could not say it was going to end up with an A-bomb, they could not say we are going to end up learning how to make plutonium. They could not say we are going to do all these things out in Hanford and Washington and we have something else going. We were not supposed to know about it but of course the pipeline tells you what is happening. Officially you could not go around talking to anybody hardly. It was not like they made you keep your mouth shut like Henry Ford did with some of his people in the plant. He used to have plant police and if they catch you going around talking while you are supposed to be working, you get fired. Well they did not do that but you were not supposed to volunteer any information, I did this for this guy over here, now how about I do this for you over here, you are supposed to just keep it to yourself and do your job. In a certain way it did not make any sense because you can get a lot more done if you sit around and talk to each other. 

Later on in the architectural world we used to have what we called brainstorming sessions where you write down all the ideas no matter how silly they sound at the time, you write them down and you evaluate them. They did not have any of that. I do not know how much money we wasted god knows but when you are at war you do not question those things, you just say okay this is they way it is, but everybody knew it was something important and after a while you begin to piece this together and you piece that together. Afterwards there was a book put out called the Smyth Report, are you familiar with that?

Cantrell: We learned a whole bunch after reading the Smyth Report about all the other places we were doing but before that nobody would tell you. They would say hey we have this going in Tennessee, we have this going in Hanford, and we have this going out here. A few guys at the top obviously knew but the rest of us did not.

Kelly: What did you know? You were working on T Metal project?

Cantrell: In the very beginning I asked my friend Julius. 

When he called up the first time and said, “Hey come down and go to work.” 

I said, “Does it have to do with radium?” 

I remember my high school teacher had said if you can ever figure out a way to get the energy that is inherent in the nucleus of radium—and that was the only radioactive material we knew about back in those days. I graduated from high school in ‘37. Of course at the college level and the university level all the sort of Enrico Fermi and Niels Bohr and all those people knew but they too were just in the process of discovering. 

I remember this high school teacher saying if we can ever figure out a way to get the energy that is stored in this nucleus, it will revolutionize things and make for a lot of energy available for all kinds of purposes. Well it kind of stuck with me and I said, “Does this have to do with radium?” 

And he [Julius] said, “I cannot say.” So right away I knew yes it did, you know, you learn these things, I said okay. So that is when I became more interested and said, “Okay I will give it a try.” And then they come along with the control rod drive and you think ah ha, they want some neutrons and that sort of stuff so you piece little things together and after a while you know.

Kelly: Another question I wanted to see if you could explain a little bit more that control rod that you said both telescoped and it moved back and forth.

Cantrell: Swung like a pendulum and telescoped in and out while it was swinging back and forth simultaneously.

Kelly: Just looking at the B Reactor and how that is designed, the control rods are sort of in a channel inside the reactor.

Cantrell: Maybe later they just went up and down, I do not know, but that was a requirement that Dr. Zinn had for us and we had to make spider gears and all kinds of things in order to make this thing happen. Now maybe later on they just decided that vertical was good enough, I do not know.

Kelly: So what is a spider gear?

Cantrell: Four prongs and it has gears on mitered forty five degrees that mesh with gears on the other wheel and that was how to get it to go back and forth in order to pull the rod in and out. Then we had it swinging back and forth and we had other gears mounted on the motors back there on a worm gear. Now worm gear is on a rod threaded like the threads on a bolt or nut and that is what made it go back and forth.

I always thought that Harry Truman and his generals should not have made the decision to drop the bomb on Hiroshima and Nagasaki. Maybe on a Naval base or something, that is really an instrument of war but these people were just people going about their daily lives and minding their own business and sure they were contributing to the war effort just the same as we were civilians contributing to the war effort. But I always felt that they sort of kept it a military kind of a thing.

But of course back in those days everybody in Japan was wicked [00:57:00] and mean and bad you know, and everybody on our side was good and wonderful and that is not necessarily the case. People are people no matter where they live and under what circumstances they find themselves and yes, I wish they had not done it, but on the other hand I think of all the medical help that the nuclear discoveries have been able to do for people and it is marvelous what they can do with cancer, what they can do with tracking diseases, what they can do with finding out diagnostically what is happening on the inside of your body where they cannot see but they can put things in or blood and that sort of thing and it allows them to take pictures and what not. That might have happened anyway, but who knows, it did happen because the Manhattan Project brought a whole new industry of nucleonics to people, even this little camera over here is a result of what we did way back then. Modified fourteen times over but still no it is all part of it, it is all here you see.

Kelly: This reminded me of radiation detection and what we have done. A guy named Jim Schoke.

Cantrell: I saw his interview.

Kelly: Oh you did okay, so did you know what was going on?

Cantrell: I did not know him. We had to make in the very beginning maybe from one of his designs even I do not know because a lot of people would come in and say, “I need this, that and the other thing” and we would look at their little ID and say okay we will make it for you. We had to make Geiger counters because you could not buy one on the open market and maybe his group actually invented those.

I remember one day somebody brought in an aluminum cigar tube, remember they used to pack cigars in aluminum tubes? And we put a wire down through the middle of it and filled it full of gas and sure enough it worked. I think they put argon  in I don’t remember exactly. It worked like a Geiger counter. We had to make a whole bunch of them. So we made Geiger counters for people.

And then they had dosage films that you put on your belt that you got every morning and you put that clip on our belt and went about your work and did all your work and then you had to give it back to the guard when you left to go home at night and they would check those out to see if you got too much radiation during the day or something. They probably do not do that anymore. I have not been around radiation and stuff like that except when I go and get a CAT scan or something like that.

Kelly: So literally some of the first Geiger counters were metal cigar tubes?

Cantrell: No, I think that was just a sample and somebody said, “Hey this is what I want” and he probably saw this cigar thing that somebody brought it into our little design group—and in the design group shop we all worked together—and said this is what I want to do. I do not even remember who it was; it might have been this guy that you talked about. So we said “Oh yeah we can probably make something like that.” So again I had to make another drawing because the machinists did not know what to do, you have to make a drawing for them. So I made a little drawing of the Geiger counter and but then after a while they got to where they could get it on the outside, they could just go buy them.

Kelly: Was that before or after the war?

Cantrell: I do not know, I do not remember, maybe after the war.

Kelly: After the war.

Cantrell: Because I remember the time we were working on CP5 they were quite plentiful, guys would have those things around us.

Kelly: That was ‘54.

Cantrell: Yeah probably. Well that is when it was commissioned but we were working on the design in ’52. It took a while to build these things you know.

Kelly: Well that is great.

Cantrell: We did a lot of innovative things there and of course there were other detectors too, not only Geiger counters but gamma, oh what did we call those things. Gamma absorbers or something like that, I do not remember. You know there are three kinds of radiation, there is alpha, beta and gammas and alphas do not do much, and you could stop those with a glass of water. The betas you could stop with a piece of aluminum but these gammas boy oh boy, they go right through just about anything so you have to be really, really careful how you are going to deal with those rays. They are the ones that kill you right off, do not even stop to say bye or leave you know.

Kelly: Well you have given us a terrific interview, is there anything else that you would like to share?

Cantrell: Oh I keep wondering what we are doing today that is comparable to that and of course as soon as I think I know of something it turns out that they are doing something different than what I think they might be doing. All of this data that they collect nowadays that everybody is so worried about getting dispensed over to the Russian or the Japanese and the Chinese, that is not going to do them a darn bit of good because what good does it do them to have American phone numbers. And our people only want to use it to set up patterns for the people that are going to do bad things. So it is the sheer volume of stuff nowadays that we just did not have the ability to track back in those days. And if we had it we might have been able to do the job a lot quicker, a lot earlier because the scientific guys would have come up with solutions to problems a lot earlier than they would have if they had been able to number one, share data, and number two, collect it. But we had no way of collecting it. 

I remember the old vacuum tubes they used to use to check the sign waves you know on various emissions. They were little bitty things about yay big around and now look there we have a big old TV, a direct decedents of that. So things move along, but today’s things I just do not know what anybody is doing that is comparable to what we did. But nowadays they have reactors that run big old aircraft carriers and submarines and I do not know what all and a lot of countries are getting an awful lot of their energy from it. 

Up in Illinois there is what thirty-seven reactors now in the whole state or is it seventeen? I do not know. A whole bunch all around, but they have not built any new production reactors in twenty years now, thirty, a long time but maybe we will get back to it one day who knows, I bet you we do.

Kelly: Great, good so I want to thank you very much.

Cantrell: My pleasure, pleased to be able to talk about it, it was an interesting time for me and I had a sense that I contributed a little something you know.

Kelly:  You obviously did.

Cantrell: Yeah, but at the time you did not know, you just hope to do what was going to work out. But it was interesting to work with all these people with brilliant minds and it was a rare opportunity. Most people do not ever get the chance to do that. In the last five years of my work for example I was a campus architect for Johns Hopkins University in Baltimore and there I got acquainted with quite a few really brilliant people, mostly working the space telescope science institute people, for example, and all the things that are going on over there.

And before that I was Project Manger for the building of the University of Massachusetts campus on Columbia Point in Boston, that was in 1970-74, so I have had a chance to be around university projects since then and it is fun to be around those kinds of people because they are on the cutting edge and the creative edge of an awful lot of things and most of us do not know anything about and do not care anything about for that matter. And yet, some industrial guy comes along and figures out a way to make a practical application, the next thing is we are using it all day, every day. Digital cameras, TVs, cellphones, whatever, that is interesting.