The Manhattan Project

Raemer Schreiber's Interview (1993)

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Raemer Schreiber worked at Los Alamos on the Manhattan Project and after the war developing the hydrogen bomb and the Rover nuclear rocket program. In 1945, Schreiber was transferred to the Gadget Division and was a member of the pit assembly team for the Trinity Test, watching the explosion from base camp. He flew to Tinian Island with two plutonium hemispheres and helped assemble the Fat Man bomb used on Nagasaki. He witnessed the 1946 radiation accident that killed Louis Slotin, but was allowed to leave Los Alamos after being examined to go to Eniwetok for the Bikini test. He recalls the challenges that went into designing the hydrogen bomb, as well as the personalities of various scientists including Edward Teller and Norris Bradbury.
Date of Interview: 
June 8, 1993
Location of the Interview: 
Los Alamos
Collections: 
Transcript: 

Raemer Schreiber: Yes, there was at least one [bomb core], and people back here worked furiously taking the plutonium as it arrived and converting it into another core. I don’t know the answer to it. I have heard stories another core was on its way out at the time of the surrender.

Richard Rhodes: Groves decided not to ship it. I’ve seen the document.

Schreiber: All right. Well, we got back. We had the celebration and Groves speaking, and then Oppenheimer saying he was going to leave and [Norris] Bradbury was announced to be the new director. I barely knew him; he was the guy in the khaki uniform and a clerk that zipped in and out at Trinity, and that was about all I knew about him.

Then he took over and made several speeches, mostly to the staff members, some to the general public locally, and then a lot of meetings that the senior people—some of whom are all packed up got ready to go and some were not quite sure what they were going to do. Eventually the same question came up: “Do I want to go back to Purdue or do I want to go to Buffalo or do I want to go to the University of Washington, going back in to physics departments?”

Rhodes: You already had your PhD?

Schreiber: Yeah, I had that in ’41. And the eventual decision was that it was more fun to stay here.

Rhodes: So there was, the sense that the lab was going to continue?

Schreiber: Yeah, well, we had, of course, questions as to how it was to continue and what would happen and so on, but then the Groves’s letter, which you know about, says, “Act like you’re going to be here for a long time.” And so we decided that it’s more fun here than it was in Indiana, and the salary at the University of Washington was barely going to make up for this beautiful scenery, so we stayed.

My job then was a group leader, so called, in the weapons development division. Work on new designs, of course, and essentially catch up with all the things that had to be skipped over in the hurry to get the Fat Man done. That was the situation until the announcement of—Groves’s letter was in January of ’46. The announcement of Operation Crossroads was also in January of ’46, and the assignment of Los Alamos to provide the reason why there was three weapons, one for deep sea, one for air drop and one for shallow water. And then the deep sea one was abandoned because logistically it was impossible to plant a bomb a mile deep and anchor ships around there and know where everything was and etc.

I was assigned as head of the pit team who had to assemble the cores into the bombs. We took a half day with the Navy architects at Long Beach, or Terminal Island, to tell them what was needed in an assembly ship. So we flew them out there in the C-54, out there about 9:00 o’clock, and talked to the Navy architects until 1:00 o’clock and flew home. That was the extent of how we were going to do it.

USS Albemarle. It was always called the “Able Mable” and it was anchored at Kwajalein for the air drop. They had two destroyers at Oakland and one core per destroyer and a small squadron of MPs guarding it, only they were paying all their attention to a big casket-like box that was anchored up on the upper deck. The actual core was in an officer’s state room next door to mine, and it was occupied by several MPs.

And so thus we went out to sea and went non-stop; well, there was a stop off of Pearl Harbor for exchange of documents or something. No, we went in and refueled, but we couldn’t leave the ship. And we got out to Kwajalein and unloaded there.

I have some place around here a knapsack that was used to take the little box which had the core in it. Roger Warner was the chief of our assembly crew. He saw one of the MPs carrying the case and had to go over the gangplank. He said, “Stop!” He got up this gunny sack and put the thing in there and got a rope and tied it to the sack. He said, “I don’t care if you fall in.”

That was one of the little stories that was amusing. We spent, I don’t know, six weeks out there, I guess, for the two shots.

Rhodes: Were these two Fat Man bombs at all modified or changed from the ones used during the war?

Schreiber: Inside, no. Outside, one was fused and armed in exactly the same way, I think, as the Nagasaki one. The underwater shot of course had to be completely redone. That was modeled up in a watertight case of the modified LSN 60 – Landing Ship Medium. They cut a hole in the thing, put a big crane overhead. This waterproof case with cables coming out of it was lowered down to something like— I can’t remember whether it was 40 meters or 40 fathoms—anyhow, halfway down in the Bikini lagoon and it then was fired by radio signals.

The Able Mable, after the air drop, went down there and we were all in the cozy lagoon there with hundreds of target ships. For the shock, we moved out to sea and only—we were maybe twelve miles, I guess. I took advantage of pseudo-officer ranking to take over the crow’s nest up in the ship with this 35 millimeter camera, and I got some pretty good shots of that firing and the great cloud.

I left out one very important thing. When we were preparing these cores [in Los Alamos], Louis Slotin was in charge of the critical assemblage and had to verify that these cores were safe to be put into a high explosive assembly, with the mockup assembly obviously with high explosives. You don’t mix the two in populated areas. And that afternoon we had to check some initiators, which were in the same laboratory where he was doing his experiment and demonstration, and had this famous accidents.

Rhodes: Could you characterize what he was doing, I’ve heard talk about a screwdriver?

Schreiber: He had essentially a spare core, which was some six plus kilograms of plutonium and which was 95% critical, and a normal uranium reflector, and beryllium reflector hemispheres – I don’t know the total thickness, probably yay so. It is super critical, because of the better reflective properties.

What he did was, he had a table like this with a stand, and put the bottom hemispheres on the table, put the core in, and then lowered the top half down using a screwdriver to lower the thing. Then he had a wooden wedge. I wasn’t over there; I was busy doing some other work within the same laboratory. And the thing slipped and it was super critical. He immediately flipped the top off.

Rhodes: The top being beryllium.

Schreiber: Went clattering on the floor. Everything went off scale, there was a blue flash, etc. He knew he had had it at that time. He kept his head. We all dashed out of the room and I went back around the corner with a meter and that went off scale, so I decided I better not go back in. I guess he called the hospital and told them to send the ambulance out. He and Al Graves were in there.

I was far enough away and Ted Pearlman, who worked with me, had come down in the jeep. So we went back and I stopped off to my apartment and told my wife that I was going to have to go and be checked into the hospital, but I was all right. Well, I was thirty feet away. So my silver coins, they were being measured to see how much radioactivity they had gotten, and it turned out that I wound up with 25R or something like that. They kept me out, took blood samples and stuff for a day or so. But anyhow, it didn’t bother my health, so I went on with going overseas.

Rhodes: Harry Daghlian had already—

Schreiber: That was another thing; this happened while I was still on Tinian.

Rhodes: Oh right, yeah.

Schreiber: She [Raemer’s wife, Marge] doesn’t know anything about the accident. She was involved—they sent for his mother; he was not married. He was a young PhD candidate. And Mrs. Daghlian came out, and I guess Norris Bradbury got Marge to take her in and she stayed there, because Marge was alone with two kids. A mutual help sort of thing.

Anyhow, that was a completely different type of thing. It was just stupid—well, both of those were stupid, because there were rules which were clearly violated. Somebody gets killed, you had to go around and say he was stupid.

In that case, that was an assembly that was made by hand with blocks of uranium, and he put a piece of tamper down on top of the assembly when it was practically critical, and that put it over. You get fooled by the fact that they lay critical; everything’s kind of interesting. The counters go up; you move something off and the counters goes down. It’s a tantalizing sort of business. But if you go past critical – I don’t know what the multiplication rate is, but it’s far faster than human reactions.

Rhodes: Otto Frisch describes the time when he was doing one of the assemblies and leaned forward, and the hydrogen was enough to make things get going. He knocked it off.

Schreiber: Well, anyhow, when we got back from Crossroads, then I was asked whether I would head up a group to put in remote assembly techniques. We built the site down in Pajarito Canyon, which is still in use. We started out with one laboratory control building, and one Kiva, which was about a quarter mile up the canyon, and troughs for putting cables. We had some of the earliest TVs, a big RCA, big clumsy things, but they were quite reliable. And so we established that sort of a procedure, and we got it operating.

One of the interesting experiments there was that we had the world’s stockpile of cores, because the military people wanted to know how to store these things so it would be safe. They were busy putting in depots at Fort Hood. It’s got to go underground. What happens if you have a bunch of cores sitting on shelves, the roof collapses on them? Well, that’s a good question. Nobody knows. So we set up some imitation storage vaults and had a regular little railroad track with a cart, which could be released or could be brought in slowly with an electric motor into this concrete shelter. We made sure the multiplication – we could put I think up to ten cores on the cart and put some more back inside this thing. We never got anything close enough to get excited about. But it was sort of an exciting thing to have the whole world supply there.

And a squadron of soldiers with machine guns ran around on the rim of the canyon. We had to wear white shirts, sleeveless shirts, to identify ourselves. I was wearing a white shirt but not with their torn off—it didn’t have any insignia, but then they had field glasses so they could see us. And they send back word to radio for “That guy with the glasses on better put his shirt on or we’re going to open fire.” So I put it on.

This took us three days. We went twelve-hour shifts, continuous operation, because there was no place to store the damn stockpile; they wanted to get back to something safe as soon as possible.

Rhodes: Where would they normally store it?

Schreiber: I don’t know; I don’t think we were told.

Rhodes: Was Los Alamos manufacturing bombs during that time? Because, you know, when David Lilienthal in the first AEC came here, early in ’47, they were horrified to discover that we had a very small arsenal indeed. I think the numbers they took home were like nine and thirteen.

Schreiber: I think we had twenty-one at the time of this measurement. To answer your question, I only can guess because that was one part of the business that nobody told us unless we needed to know. They all came through here for a check-in. The first few were probably out of the DP site here. But then who the heck did it? Rocky Flats wasn’t going.

Rhodes: Was Sandia going yet?

Schreiber: No, Sandia was just getting started. Well, maybe we did the first twenty or so.

Rhodes: I think I have seen something that indicated that the first ones were done here.

Schreiber: Well, here it’s checked. On one of the routine assignments at this laboratory at Pajarito was to take these in there and put them through this mockup HE. One of the first major jobs, when we got our Kiva built, was to go out there with a concrete mixer and several tons of carbon dust and paraffin. You got to have the right combination of non-explosive of Comp B. The neutron doesn’t care what its chemical properties are.

Rhodes: Yes.

Schreiber: It just wants to know how many of the right kind of atoms are there. And it says, “Okay, that acts just like high explosive.” Anyhow, we did that and cast it, heated up our concrete mixer and made up this goop, which we poured into big castings that would hold—they were standard grid Fat Man castings. Then they had assemblies arranged with hydraulic cylinders—pneumatic cylinders, we didn’t use oil so much—that would drop everything apart and haul it up if anything went bad. If somebody put in an extra 500g of plutonium, you’d get in trouble.

This still was done remotely. You got it set up and you went back and you locked the gates as you left, and went back to the control panel and pushed a button that pushes the things together and you watch with TV and with monitors. So that was the procedure from there on.

Well, this gets to be a very long story. About a year after that—

Rhodes: That was when?

Schreiber: We started our building and it actually was underway when I got back from Crossroads, which would be the middle of summer ’46. The fall of 1947, I was asked to move into the W Division office and be part of the broader picture of the nuclear part of business.

W Division had responsibility for everything inside the high explosive. GMX Division had responsibility for everything outside of the explosive and the detonating system and the arming and safing of that part of it. At Sandia was the transplanted X division, moved down to Sandia Laboratory, they had all the arming and fusing and the ballistics and the interaction with the military. That’s one reason they went down there. Kirkland then was set up as the three service type of coordinator for the atomic bombs. So that was part of the pattern of the laboratories, as far as the weapons were concerned.

Rhodes: I’m puzzled because Lilienthal said that when he told Truman how many available weapons we had, he told him zero. I gather that was because it was a problem maintaining initiators—that the polonium would decay?

Schreiber: That was one problem. It called for an exhuming of the cores, which were stored separately on these so-called root changes. Each core went into a holder, which was sealed up and had a desiccant to keep it dry and stuff like that. And then the birdcage was “yay” size.

Rhodes: Half a meter.

Schreiber: Half a meter, more or less, so that you could stack an infinite number of these without getting into any trouble.

Rhodes: Was it actually a wire structure?

Schreiber: It was a stainless steel pipe, half inch maybe, quite rigid. It was designed so that the roof could fall on it without scrunching it down.

Rhodes: Why was it open, so the heat could dissipate from the core?

Schreiber: It was just a tube, as you would build it, with a couple of diagonal things to strengthen it. Then a canister big enough to hold a core was set down in the middle and locked in place. These were the standard ways because you could shut them, just put them on the truck and tie them down. You didn’t have to worry about whether the load was going to go this way and that, because it was big, strong and, inherently safe.

So I got up into the office. That was my beginning of getting involved in management, because one of the things which Norris took over, of course, was a completely disorganized laboratory. Half of the senior members were going back to their old jobs. They had a whole bunch of new people, and not much in the way of a pattern of organization. And so one of my assignments as an associate division leader was to participate in the personnel advisory panel. How do we set up business to take care of staff members, assistants, deputies, clerks, technicians etc.? And this was in a sometimes very disgusting length of debate, a whole bunch of amateur professionals in the business of personnel management. Well, now that was part of my job. One can go into great detail on these things.

Rhodes: Is Teller right, did Oppenheimer want to shut this place down in ’45? Teller loves to tell this story of Oppenheimer who said, “Give it back to the Indians.” Does that square with your knowledge and experience?

Schreiber: That sounds like the parody that the British Mission people put on here before they left.

Rhodes: You showed us those photographs last night.

Schreiber: Yeah, they were trying to give it back to—was it Jim Tuck? Was he the Indian? I think he was. He was the Indian in a blanket and a feather. He wouldn’t take it. He didn’t want it. [Laughter] They even offered him a bottle of whiskey. He would take the whiskey but he didn’t want the place. They were screwy events, but they had fun. I don’t know anything about his particular quote, but that sounds like that same story.

There was of course during the rest of ’45, up until the time that Groves’ letter came out, nobody knew anything, really. That’s when we had the Los Alamos University, senior people would give talks and there was talk about getting graduate credit if you went through all these lectures and so on. But it sort of dribbled out, because it had a changing audience all the time. People were going, other people couldn’t make up their minds.

It wasn’t until perhaps May of ’46 that Norris finally screwed up his courage and sent out the letter to all concerned: “If you were going to go home, go home, because after September 1st we’re not going to pay your way.” Because he was stuck. He had people, the acting division leaders who kept saying “Well, I don’t know if I’ll be here next month.” You couldn’t do any long-range planning, so he just finally decided, “If you’re going to go, get out,” in politer language.

Then the decision was made to try to do some new designs and fire them off out in the Pacific. That was the establishment of our test organization out on Bikini, to start with, and then Eniwetak took over. We were busy then with the modifications, making smaller bombs, and getting in coordination with military people, “What do you want?

And they always said, “Well what can you make?”

And we said, “We can make one like this.”

“Oh yes, well, that’s what we want.”

You started the business all right. The Air Force, of course, didn’t want anything that was as clumsy and poor balistically as the Fat Man, and so that got streamlined down. Then we found out that the half-scale model, which had been used here for tests, might even work, and that would cut down the weight of the thing from whatever it was, about 6,000 pounds to about 2,000 pounds. That was the Mark V.

Rhodes: Half-scale? Because it was smaller explosives assembly?

Schreiber: Well, it had to be adjusted to the right dimensions, but it was same basic idea and they had used it here to try to get a measurement of the symmetry. All of this was very difficult. You’ve got a couple tons of high explosives that’s bent like this and also like this, and you want to know what’s going on down in here, in the middle. Take it easy.

That’s how all of the electrical, some of the very clever Swiss watch type of assembly was done, with wires terminating into this small space. You can’t put a complete sphere, but you can put maybe three-quarters of a sphere and get the signal out before it all blows up at that point. So there was some very clever work done during those years.

Well then we went—I never can remember the code names of the overseas tests, but we had one in ’48.

Rhodes: That was Sandstone.

Schreiber: And right about every year after that. And then the next big event, of course, was the thermonuclear business. It was debated at length, at high levels—

Rhodes: Before you go to that, let me ask you about—at the very beginning after the war, when you started work again, what was your sense of what your mission was here? Was the Russian issue already there, or was it just in general that—

Schreiber: I think in general it was—people started being suspicious of the Russians, the Yalta Conference and all the difficulties and the way they were marching into Eastern Europe and establishing they were going to make that whole thing up to USSR. So there was that suspicion, although I think the other side of it was the feeling that there had been so many compromises—not compromises—so many precautions taken in building the Fat Man.

Rhodes: In terms of conservative design?

Schreiber: Terribly conservative design. There must be things that if you could just test – all right, let’s try making this smaller, changing this. There were new ideas about instead of having everything a solid thing, maybe you can levitate this. You can pick up an awful lot of energy concentration in empty space if everything is coming into it, you see, from a bigger dimension.

All of these ideas, plus the military requirements and the general feeling that there were many efficient ways of making an efficient delivery system; that was the concept that you started out with. The Fat Man started out by being the biggest thing that you could get into a B-29 bomb bay, past the doors.

Well after that of course, you started getting aware of the fact that the thing’s no good if you can’t get it off the ground or you can’t get it where you want to blow it up. And so this had to be the idea working with three services on “What is it you want?”

That gave you enough work for a much bigger laboratory. You had the money for it and the Joint Committee [on Atomic Energy] urged you on, and the AEC didn’t bother you much because they didn’t want it any more than we did. So this was a very happy time from the standpoint of a peaceful, friendly environment for making deadly things.

Rhodes: Ted Taylor calls it “The Golden Age.”

Schreiber: He had a big role in this. A lot of the ideas of how it would start out with the Fat Man and go into this and this and this variation came from him. And he was a very articulate convincer of the powers that be here, that this is the thing to try.

Rhodes: Levitation had been thought of before the end of the war, I know, because David Greenglass discussed it with the Soviets. Had the composite core idea also come up?

Schreiber: Well, it was thought about by the end of the war. People were worrying that we had all this U-235 business going, and a very, very clumsy way of delivering it, of using it. Because the gun is a very inefficient mechanism. I guess boosters have now gotten declassified, and that was about the one thing which they could do to make it more useful. So the idea was, “Plutonium is expensive, you’re making lots of it but you’ve also got this big plant going separating U-235, and what are we going to do about it?” And so the composite idea was very useful. I can’t tell you who first thought of it. All of these things got kicked around here in the technical working groups.

Rhodes: Was the composite core only to use up extra uranium, or was it also technically advantageous?

Schreiber: Well a little of both, I guess. Plutonium was not in good supply, for one thing. So you had two separate production lines, which the people who got into the whole picture were worried about. You got so many tons of this coming in and so many tons of this coming in; how can you best use it? We might have been asked for the answers, but we weren’t always told what all was going on at Hanford and Oak Ridge. Unfortunately, Max Roy, who has passed on, did know all that. He was Norris’s assistant for production and did the liaison work to keep track of what was coming in and going out.

Rhodes: So you started to say, “Then along came the business with the H-Bomb.”

Schreiber: Yeah.

Rhodes: Do you remember hearing about the Soviet test? What happened here, when the news came that the Soviets had tested their first atomic bomb in—what was it, the announcement was in late September of ’49? Was that a shock?

Schreiber: The fact that it was that early was a shock, because everybody who was making predictions was saying, “They’re not very smart and they haven’t got much money and so it’s going to take them ten years.”

I don’t think anybody was fooled into the notion that only in America could it be done, but it would take time and it would take a lot of money. And in particular, it took a very competent, big industrial complex. So, yeah, it was a shock.

Of course, it was the impetus to keep one jump ahead build-up at that time. That was when people started the laboratory. It didn’t do much except to fuss with the idea of fusion, making measurements. Then in the second overseas test, there was a test of boosting. The feasibility of building a composite bomb, which would get most of the energy from thermonuclear reactions came up, but nobody could figure out how to get the things started. That was when Edward got quite annoyed with this, because nobody would just go out and build the great big thing and see if it would work. It’s an expensive business. If it didn’t work and you didn’t know why, it was a wasted effort. So that’s part of where this internal controversy kept going on.

Rhodes: I should tell you, the Soviet bomb that they tested in ’53, Joe-4, was alarm clock-like. It was a series of concentric spheres of lithium deuteride and uranium. And they got 400 kilotons. We talked to [Hans] Bethe about that a month ago, and he said, “I don’t know how they did that. We weren’t able to figure out how to get enough squeeze, high-explosive squeeze to get our alarm clock started.” That was his explanation. But somehow the Soviets did figure it out. It was the Sakharov design.

Schreiber: All sorts of reports.

Rhodes: There seems to have been a fairly serious effort here for a long time to work on the alarm clock until the Teller-Ulam idea came along.

Schreiber: Well I can’t add much to that because all I know is what I heard other people say that someone else said.

Rhodes: What were you working on during that time?

Schreiber: We were just busy building a stockpile for the Army, Navy, and the Air Force.

Rhodes: Okay.

Schreiber: And worrying about the maintenance, because all of the regulation—the usual story is, first you got to make them GI-proof. You got to write your manuals so that a guy who doesn’t have much training can handle these.

I was also the Dean of the Nuclear Officer’s Training School, which they ran here for a number of years. The military people would send in a crew of fifteen to twenty junior officers, lieutenants, captains in the Army or the Air Force, and lieutenant commanders. The Navy was further ahead on this business than either of the other services.

Rhodes: What period are you talking about, early ‘50s?

Schreiber: Pardon?

Rhodes: What period of time are you talking about? That’s interesting.

Schreiber: It was like six months—maybe it was a year. They were brought in—

Rhodes: I mean starting around what, ’48 or ’49?

Schreiber: I would guess the first ones came in here about ’48.

Rhodes: See I had the impression that the Air Force got all the bombs at first. Is that true?

Schreiber: Yeah, they did because we only knew how to make bombs. The Army fusing compatibility with aircraft was the top priority. The Navy was slower in the early start. Rickover and the group and the group at Oak Ridge during the war, and Rickover beat them into really service parallel status of understanding what’s going on in the nuclear business. I was involved after I retired, and reviewed the classification of some of those documents. We weren’t allowed to classify or declassify the Navy ones, but we were allowed to read them.

Rickover had classes five days a week with his officers. They went through a very detailed business of what makes bombs work. It was all elementary, in a sense, but it was very comprehensive. And so he had the ideas, but the complications of building nuclear submarines took a little more than knowing what a neutron would do. Those were very senior guys that came in, superior.

That was one of my goofs. I was supposed to sign their fitness reports. I said, “Oh yes, they are pretty good.” I had a man in the director’s office who was an ex-Navy guy and he came storming over and says, “You sent these in. You’re ruining these smart guys. You got to say they’re superior, their performance is wonderful, etc., etc.”

So I said, “Okay. You fill these out and send them!” [Laughter]

They were very good, but they were comparable. They went to school here, we had lectures for them, then we assigned them to groups throughout the laboratory. They got a chance to pick. If they were interested in chemistry, or metallurgy, go over there, if they had some theoretical background, they’d go down to T-Division, and so on. Then they got like three months of actual service in the laboratory after they’d complete their training. And they went out and became admirals and generals. That was in the very late ‘40s, early ‘50s.

These same people approached to get into the planning side of the business when they got back to their other military jobs. We could call them up and say “Hey, Bill, blah, blah, blah, blah. We need some support from your office, from your bosses, to get this one going.”

This was a underlying technical exchange, informal, but it kept things moving. So these military staff members—there are two admirals who retired in Santa Fe now who went to my school.

Rhodes: That’s a very different picture of one aspect of Los Alamos that I think isn’t well known, the training part. The liaison part with the military.

Schreiber: It was our responsibility, particularly in the two divisions I mentioned, the W and DMX, to write the procedures, approve the storage procedures, make sure that people have the right information, the right tooling for the storage and the assembly of the weapons under their control. And one of the reasons was that the early weapons, the polonium thing meant that you had to haul these things out, take them apart, and put in new initiators every two years, or something like that. So every storage sample—

Rhodes: What’s the half-life, it’s like every 120 days, isn’t it?

Schreiber: Yeah, but you can put in enough—

Rhodes: To last.

 Schreiber: Between my bad memory and the fact that everything was classified and if you wrote it down you had to leave it there at the laboratory anyhow, I don’t know some of these answers.

Rhodes: Well, but certainly they did have to be replaced.

Schreiber: There had to be a qualified crew that could take these canisters and their birdcages out into a clean room, take them apart, put in the new parts, and fill out all the paperwork which says, “This is a good one,” and that’s a career in itself.

Rhodes: Again, I gather early on there were not a lot of available assembly teams that were trained. What did it take, several days, to assemble a Fat Man at that point?

Schreiber: Not really. Well, it depends where you start from. In the typical storage configuration, no, you could do it in half a day, I expect, because you had the high explosive assembly pre-assembled in its case. That could be built out, the core loaded in, in a matter of hours, couple hours.

If you put the detonators on the outside first, if you start with detonators in it, then it’s a matter of getting the key signal on the outside, then having the Army and firing crew putting in their gadgets. If you want it for more or less permanent storage, you have the high explosive assembled and no detonators, in fact no electrical anything in that particular igloo. So I expect you’re talking about sixteen to eighteen hours of work time to be able to take it out and stick it into an airplane. I don’t know; I never got that far.

Rhodes: You didn’t train assembly teams, for example?

Schreiber: We put out manuals for these guys and we observed them. Some of the people in my groups did go out to various sites and watch them work, make sure everything was done all right, or if they got into trouble because we hadn’t put the right words in or something like that. So there was quite of bit of interaction with them.

Rhodes: The description of having to deal with all these components reminds me of a phrase I noticed, something about a wooden bomb. The idea of having a bomb that was essentially already sitting there ready to go.

Schreiber: Yeah. Well, one of the things which did come out was part of the job that we were doing at the time, in the early ‘60s, was to devise a way of having a bomb which was loaded into a B-47, bring the car out, and after take-off, you had an arming officer put the stuff in there, so you could have a safe take-off. Well, safe from the standpoint of the people down below on the ground. If your airplane is going to blow up, it doesn’t make much difference if it’s high explosive or nuclear to the guys on the crew. Arming after take-off was a fairly major assignment.

We had them in stockpile. But nobody quite liked them. You get up in an airplane bucking around and you’re handling a fairly heavy object, you have a little derrick, stuff like that. It was not elegant.

Rhodes: So you moved to designs that were already assembled, right? How were they safed?

Schreiber: I think they had to be in this form, and I’m being a little vague here because I’ve forgotten how far we did go with that. I think most of those were nuclear safe until after take-off. I’m putting the thing down for emphasis necessarily. Your problem was logistically a mess, because you had this canister, which the guy was taking off, carefully guarding. You have to control the flight, so below 10,000 or 11,000 feet, that’s where all the weather is, so you’re bouncing around and so it wasn’t very good. 

If you had a real emergency and you wanted to get up over Turkey or into southern Russia in a hurry, I have a suspicion that this was all done on the ground. I can’t prove anything. There weren’t any nuclear bombs in Turkey anyhow.

That was part of our assignment here, establishing the procedures as far as care and feeding of the weapon was concerned. What the military really did was their responsibility, so I’m pretty ignorant on that.

Rhodes: I have a cousin who was a SAC general who remembers arming those weapons in flight; he said it was a helluva job.

Schreiber: It is, yeah. You put the bomb on the end of a rod or something, you’re crawling around in an airplane. You don’t like that kind of business.

[Laughter]

So that gets us up into November ’51, which was a famous time when the decision was made to go all out for the Mike Shot. It took exactly one year to do it. This was when Edward [Teller] stomped out of the room and said, “I’m leaving the laboratory.” And that’s when he started at Livermore.

Rhodes: But in fact work went on here.

Schreiber: Yes. Marshall Holloway was appointed as DIR-X, X meaning anything you want to do. He was assigned the responsibility to take anybody in the laboratory he needed, give out work assignments. We were all on a six-day work week. This was the position I think Edward wanted. He has no sense of how to get a place organized. He’s a very smart guy in his field, but terrible administrator, I’ll tell you.

Anyhow, Marshall took over. I was working as a deputy to him in W-Division, so I had to take over W-Division. We only got in on bits and pieces of the thermonuclear Mike Shot, because our job was to get them a nuclear trigger. We did some work with the interaction – not that early, but the next year, after Mike Shot went off and blew a hole in the island.

Then the question is, how do you get whatever that was, 86 tons of stuff, into an airplane and fly up? There was a whole series, from the more pessimistic, ultra-conservative type that would conveniently go into B-36, it would go into a B-47, but you had to refuel almost as soon as it got off the ground, because you couldn’t pick up all the fuel weight. I don’t know the exact details. But the idea was that it had a very short range, so you’ve got to have a tanker circling overhead before you take off.

That was the one that got us in all the trouble with the islands out there. When that was tested, it was the one that sprayed the atolls out there with radioactive fallout. So fortunately we didn’t have to finish up that. We had a whole series of more and more un-conservative things, which started off with the hydrogen tankage business, in the bomb, which was a logistic horror.

Rhodes: Cryogenic systems and so forth?

Schreiber: Yeah. So they got this down to the solids and they got a smaller one, which was called the runt. It wasn’t expected to work, but it did. And that was our job for the next several years, getting those weaponized and transferred to the military people.

Rhodes: Was it Harold Agnew in April here said something about a last minute change in the primary on the Mike Shot that was ordered. Do you recall that? Who did he say was responsible for that? Was Marshall Rosenbluth involved in the Mike Shot, or am I mixing up two names? Rosenbluth?

Schreiber: Rosenbluth, he was involved in the calculations; yes.

Rhodes: The story is not quite clear. Rosenberg?

Schreiber: Rosenberg?

Rhodes: Perhaps save the Mike shot – this is Harold Agnew – he lay awake worrying about the particular primary we were going to use. He convinced Carson [Mark] to change it. Maybe it would have worked, maybe it wouldn’t.

Schreiber: Well that must have gone on inside closed doors. Because I don’t know anything about it. We used the Mark V, but we may have boosted that up and put in a bigger core.

Rhodes: Well, I’m going to see Harold, so I’ll ask him.

Schreiber: That brings us up to about to where you’re going, in your book. In 1955, I was asked if I wouldn’t like to start a small, steady group of nuclear rockets. And this wound up in the Rover Program. It had a very successful set of ground tests finally, about the time the federal government decided that they didn’t need one.

We know how to make a nuclear reactor that will produce up to 500,000 pounds of thrust. But nobody wants it. And I don’t blame them, because it’s messy, and it would take an enormous stage to carry it off hydrogen, to make it worthwhile. This is when we were talking about sending men out into space and bringing them back, putting another smaller reactor system on top to bring them back after you get them out and ship around Mars or whatever.

Rhodes: You were involved in the work on the nuclear airplane?

Schreiber: No, except that we inherited the Air Force office that was in charge of the Air Force nuclear airplane. We came in just as it was falling apart. So we got General [John] Kern, who was on the verge of retirement, and Jack Armstrong, and other military officers who were very glad to see us. We worked with them briefly. Let’s see.

We started our study— there had been an informal study going on. I wasn’t involved with it because I was busy running W-Division. They started a formal study in the middle of ’55. It took us a year plus to actually get support from the AC and Air Force. The whole Looper Committee had to study this. I lived on an airplane between here and Washington for a year. In November of ’56 they said, “Okay, you go to Los Alamos. And Livermore, you make Pluto, the nuclear ramjet.”

So we had a year and then Sputnik went up. That started the whole change because when we were interested it was because chemical rockets weren’t doing very well on ICBMs. That was what we were supposed to do, was to supplement those. Johnny von Neumann told the Air Force Advisory Committee, of which he was a member, “You ought to look into this nuclear business. You don’t have enough energy, you can’t get your rockets flying, so do something about it.” He says this to General [Bernard] Schriever, and that gave us the green light to spend a little money, like a couple million dollars, to study the thing.

Rhodes: I see; I didn’t realize there was that connection.

Schreiber: [Darol] Froman was the deputy to Norris at the time, and he was a member of the Air Force Science and Advisory Committee and invited me along to Los Angeles, where they were meeting. So we got to sit like mice in the corner in the back of the room when all of this went on. The Air Force was catching hell from the committee, because about one out of three Atlas missiles never got going, or went in the wrong direction or something, blew up.

So that was an interesting beginning for this thing. So we could go ahead. We and Livermore were competing for this. I’m not quite sure why we won out. I think it was because we had a very strong chemistry and metallurgy outfit. The secret to getting a nuclear rocket was to get extremely high temperatures. Jim Taub, who was here last night, his group made all the field elements, graphite and tantalum and everything that was high-tech. [Laughter]

Rhodes: Did you go out to Eniwetok for the Mike Shot?

Schreiber: Yeah. I was out there. I had a group, the pit crew that had to assemble the primary. I was a little puzzled by the change in the primary because I think what we did—a few gray cells are coming back to life—was to put in a high core loading, about as high as we could safely put in, to increase the yield of the nuclear, temperature, etc. I was there, and we loaded the thing in.

Rhodes: So this was that big black building sitting out there on Elugelab.

Schreiber: Elugelab? Yeah, I think that was it.

Rhodes: There was this big tank; I’ve seen photographs, there’s one in my book. This huge cylinder with the primary inside it?

Schreiber: Yeah, near the top end, there was a manhole essentially that you could use for the loading. The bomb was put in some place in the process, but then the core was loaded in the night before, maybe two nights before.

Rhodes: And then there were some ports that were sticking out the side, which I assume were diagnostic ports.

Schreiber: Yeah.

Rhodes: They were presumably attached to something. The one I saw there, was no attachment.

Schreiber: Well there was also a great big helium-filled tunnel that EG&G had built to study the spectrum, I think. Or else get far enough away that they could get their data before the thing went up, before the shockwave got out there.

Rhodes: You were at Trinity, then you were at Bikini, then you saw Mike. How did they compare in terms of the explosion?

Schreiber: Oh, Mike was much more spectacular, as we were only about 30 miles away, and it really filled up the sky. Visibility wasn’t terribly good because there were clouds around. It was awesome. It just went on and on and on. I mean, the light. You didn’t feel so much heat. We were a little over the horizon at 30 miles. We definitely were for the real initial blast, as the cloud rose, we got a direct view. But the big heat flash got dispersed by having to come over the curve.

Rhodes: Was it significantly larger yield then you anticipated, or was it 10.5, I think?

Schreiber: I don’t know anybody that predicted the yield with confidence. I think the main concern was whether the whole theory was correct. I don’t remember what the range of yield calculations were. I think the important thing was, “Will it indeed ignite the fusion reaction, and if so how will it propagate before things blow apart?” And so I think that anything within a factor of five was not unexpected.

Rhodes: Did it perform the way people wanted it to?

Schreiber: I think so.

Rhodes: So it became the basis for the designs that followed?

Schreiber: Yeah. But it became the basis also for whatever that next over big shot that was—

Rhodes: Bravo? The Bravo shot that was 15 megatons?

Schreiber: I can’t say that’s for sure, but probably the Mike shot was diluted by the fact that we wanted lots of data so they had holes in it, your port holes and stuff like that, permitted some energy to leak out that would otherwise propagate. The geometry inside was not the same because you’re constrained by having an envelope inside that had to fit inside an airplane, and so people were a little leery about what you were going to learn if you move this over here and this over here, etc. Well as it turned out it was all beneficial move, apparently, from the standpoint of the yield. But I did not go out for it. That was one that I got the square wheel medal for staying at home. [Laughter]

Rhodes: You mean the big one, the Bravo shot.

Schreiber: Yeah.

Rhodes: That was designed to be air transportable, potentially?

Schreiber: Yes. Again, what’s the biggest airplane the Air Force has, and how big can we make this? And of course it was liquid hydrogen. It was a cryogenic mess also. I don’t know why any pilot would want to take off with that.

Rhodes: During the time when the hydrogen bomb decision was being debated, I had the impression from the literature that there was a lot of debate here and anger here. Was there a real battle royale going on, back and forth?

Schreiber: No, I don’t think so. Edward was back and forth, and of course there were people like Hans Bethe and Rabi that were in a government advisory position. They were the ones that were doing all the hot debating. The people in the laboratory were worrying about getting their current assignments done. They didn’t get involved in this very much. I don’t know if we ever had a seminar on the debate, which you would expect.

Rhodes: Maybe I’m thinking of a little bit later; why was Teller so angry that he decided to leave the laboratory?

Schreiber: Because he didn’t get the job of building Mike.

Rhodes: Oh.

Schreiber: He had invented it, he should be able to build it, and build it to suit himself.

Rhodes: But he was involved in the design, wasn’t he?

Schreiber: Well, sure. He was involved in the decision to make Mike. He went off in a huff and he may have been back, but I think that his issue was that a lot of vital decisions about the design were made in his absence.

Rhodes: So who really designed that device?

Schreiber: I wish I could tell you, but I don’t know.

Rhodes:  Was it Harold Agnew, for example?

Schreiber: Harold is not a theoretical physicist.

Rhodes: Dick Garwin has said, “I designed Mike” and I’ve heard people say, “No, that’s not true”.

Schreiber: Well, it was designed essentially by committee. Oh heavens, it must have had some sort of code name. “Family committee” is what I think they finally called it. The theorists would say, “We need this and so.” The experimentalists would say, “You sure you need that? Because that’s a hell of a thing to try and make.”

 They met probably once a week and went into session for a couple hours while the latest ideas were kicked around. These would be the division leaders. Carson Mark would be there, and any expert in town – Garwin or Bethe. I don’t know whether von Neumann was involved in that or not. And of course Ulam, who was just as impractical as Edward, but a smart guy, a smart mathematician, would get involved in it.

So you say, “Who made this?” [Inaudible] They built the case. It was very much a group effort. This was one reason, for example, that Norris never would give individual credits on any of these projects. Because he said, “I’ll leave out somebody, and their feelings will be hurt.” So it was done by the laboratory.

Rhodes: Did it correspond in complexity and difficulty of design to Fat Man? It took a lot less time. One could say it took a year.

Schreiber: I don’t think you can answer that question, because Fat Man came at a time when nobody was caught up into the thing and had had the experience. You had all the experience of Fat Man and an awful lot of development of good metallurgical techniques, methods of making heavy equipment, not necessarily for the laboratory or for the nuclear thing. But all of the experience that had been accumulated during the war. We used to pop out ships once a day. Things like that. You had a whole new capability available. Of course, the cryogenics is a miserable business, which we’d had some experience, not very much, not on a large scale, so that would make it much more complicated job.

Rhodes: I remember Luis Alvarez telling me what a scale-up it was for him to develop the hydrogen bubble chamber. That working with liquid hydrogen at that volume was just very risky, and that was late ‘40s, just around the same time.

Schreiber: We learned stuff about that in the rover business. We had half million-gallon tanks of hydrogen out there.

Rhodes: Wow! That’s a big bomb right now.

Schreiber: You treated it with respect.

Rhodes: Sure.

Schreiber: Chicago Bridge and Iron built it, and in fact for convenience they built it over near our control point and hauled it out to the test site which was quarter of a mile away across the desert. A whole bunch of caterpillars.

Rhodes: So it sounds as if to talk about the design of the Mike shot, I should be talking to first of all Carson Mark.

Schreiber: Yeah.

Rhodes: But Agnew was around then. He at least he seems to know something about that.

Schreiber: He was involved.

Rhodes: He was involved, good.

Schreiber: What more was he doing then? He was back from—ask him.

Rhodes: I hear through the grapevine that you’ve written out some of these memories. That you have kind of an autobiography that you put together?

Schreiber: I have sort of an—

Rhodes: You don’t suppose I could get a copy, do you?

Schreiber: It’s not fit! [Laughing]

Rhodes: It’s as fit as a tape recording.

Schreiber: Well, what I have written is mostly the interaction of the top brass. How they changed, how it was influenced by Norris. Because he started out with the idea that “a scientist can do anything. The laboratory is for scientists. If a scientist can learn to manage, fine. You can’t hire a professional manager and teach him to do things the way a scientist needed.” This is the philosophy in a nutshell, more or less.

He got by with it pretty well. Oh, sure, you hire an accountant, of course, it’s a dull business. You hire a guy who knows how to buy things. But for running things, including personnel, you get an engineer who understands what’s going on in the laboratory and therefore can do a better job of setting up personnel standings and so on.

If you hire a staff member, you don’t make him punch a clock, and you don’t give him any overtime. If he needs to work over Saturday and Sunday to get the job done, he should do it. But if he wants to take off a day and go skiing, that’s okay too. But he should have either the characteristics that this ethic require that he do what the job require. That’s fine.

This was one of the things, of course, that with the laboratory growing it’s much much more difficult. You start getting into the problems of what’s the break point between hourly and—

Rhodes: Salaried?

Schreiber: Hourly employees and professional employees, there’s a technical term for it. That’s where you get into all the trouble. Hourly employment stays all overtime and gets time and a half and maybe double time on Sunday, because it’s under the fair labor standards business. And here’s his boss and only makes two-thirds as that guy. Now what you going to do about that?

Anyhow, if you take the data, you get from whatever we were at the end of the war – 3,000 or so – up to close to 7,000. Now it bounces up and down. It’s a different system, because a lot of stuff is farmed out and subcontracted, which we just took care of it ourselves. So life is difficult nowadays, we don’t have all the friends in Washington that we used to have.