Operation Crossroads at 70

This summer is the 70th anniversary of Operation Crossroads, the first postwar nuclear test series. Crossroads is so strange and unusual. 1946 in general ought to get more credit as an interesting year, as I’ve written about before. It was a year in flux, where a great number of possible futures seemed possible, before the apparently iron-clad dynamics of the Cold War fell into place. Crossroads happens right in the middle of the year, and arguably made a pretty big contribution to the direction that we ended up going. Such is the subject of my latest article for the New Yorker‘s Elements blog, “America at the Atomic Crossroads.” Today is the anniversary of the Baker shot, which Glenn Seaborg dubbed “the world’s first nuclear disaster.”

America at the Atomic Crossroads

There are a lot of things that make Crossroads interesting to me. The bomb was still in the hands of the Manhattan Project. The Atomic Energy Act of 1946 had not yet been signed into law (Truman would sign it in August, and it would go into effect in January 1947), so the Atomic Energy Commission did not yet exist.

There were these amazing interservice rivalry aspects: the whole backdrop is a Navy vs. Army tension. The Manhattan Project, and the Army Air Forces, had gotten all the glory for the bomb. The Navy didn’t want to be left out, or seen as irrelevant. Hence them hosting a big test, and glorying in the fact that a Nagasaki-sized atomic bomb doesn’t completely destroy a full naval squadron. (Which was no surprise to anybody on the scientific or military side of things.)

The US had only about 10 atomic bombs at the time. So they expended about 20% of their entire nuclear arsenal on these tests, for relatively little military knowledge gained. The Los Alamos scientists were pretty lukewarm on the whole operation — it just didn’t seem like it was getting them much. One wonders, if the bomb had not still be under military control, whether it would have happened.

Photograph of the early mushroom cloud by LIFE photographer Frank Scherschel, with a darkened filter to compensate for the brightness of the flash. Source.

Photograph of the early mushroom cloud of Crossroads Able by LIFE photographer Frank Scherschel, with a darkened filter to compensate for the brightness of the flash. Source.

The first shot, Able, was something of a flub. The fact that it missed its target meant that for public relations purposes it was seen as very ineffective, but it also means that their scientific observations were largely pretty useless. In fact, it missed its target and blew up over one of the main instrumentation ships.

If you read most sources about Crossroads they will say that the source of the Able miss was undetermined, but if you dig down a little deeper you find some pretty plausible solutions (and the reason why the official verdict was “undetermined”). Paul Tibbets, the captain of the Enola Gay and overall head of the atomic delivery group, was pretty clear that it was human error. He said that even before the shot they realized that the crew of the B-29 which dropped it, Dave’s Dream, had gotten bad information about the weather conditions, but that they ignored attempts at correction. Tibbets would re-run (with a dummy bomb) the drop with the correct information (and got very close to the target), and also re-ran it with the wrong information (which missed by nearly the same amount as the Able shot). But the USAAF really didn’t want to throw their bombardier and plane crew under the bus. So they hinted it might be a problem with the ballistics of the weapon (which were indeed a bit tricky), which infuriated the Manhattan Project officials. Anyway, everyone seems to have been satisfied by just saying they couldn’t figure out where the error was. But Tibbets’ account seems most plausible to me.1

Crossroads was not secret operation, though there was much classified about it. There were full-spread articles about its purpose in national news publications both before and after its tests. There was probably no test series so publicly conducted by any nuclear power — announced well in advance, covered by the press in real-time, and then heavily publicized afterwards. The fact that the Soviets were invited to a US nuclear test operation (something that would not happen again until the late-1980s) opens up whole other dimensions.

Mikhail Meshcheryakov ("Mike"?) in 1946. At right he is on the USS Panamint, at the Crossroads test. Source: Mikhail Grigorivich Meshcheryakov, on the 100th-anniversary of his birth (Dubna, 2010).

Mikhail Meshcheryakov  in 1946. At right he is on the USS Panamint, at the Crossroads test. Source: Mikhail Grigorivich Meshcheryakov, on the 100th-anniversary of his birth (Dubna, 2010).

The Soviets had three observers at the test: Professor Semyon P. Aleksandrov, a geologist who had worked on the prospecting of uranium; Mikhail G. Meshcheryakov, an experimental physicist; and Captain Abram M. Khokhlov, who attended as a member of the international press corps (he wrote for the Soviet periodical Red Fleet). I found a really amusing little anecdote about the Soviet observers from one of the men who worked the Manhattan Project security detail on Crossroads: Aleksandrov was someone they knew already (he was a “dear old geologist”), but Meshcheryakov was someone “whose name was known, but no one had met personally leading some of us to support he was really an NKVD agent watching Aleksandrov.”

I found nothing in the Russian source materials (mentioned below) that would indicate that Meshcheryakov was NKVD, though he was definitely the one who wrote up the big report on Crossroads that was given to Beria, who summarized it for Stalin. Meshcheryakov’s report is not among the declassified documents released by the Russians, so who knows if it has any political commentary on Aleksandrov in it. Meshcheryakov ended up having a rather long and distinguished physics career in the USSR, though there is almost no English-language discussion of him on the Internet. Aleksandrov, the “dear old geologist,” was actually a major Soviet big-wig in charge of mining operations, which at that time meant he was high in the Gulag system, which was run by the NKVD. For what it’s worth.2

Radiation from the Crossroads Baker shot — the radiation went up with the cloud, and then collapsed right back down again with it, resulting in a very limited extent of radiation (the entire chart represents only 4.5 miles on each axis), but very high intensities. Chart source: DNA 1251-2-EX. Collapsed cloud picture source: Library of Congress.

Radiation from the Crossroads Baker shot — the radiation went up with the cloud, and then collapsed right back down again with it, resulting in a very limited extent of radiation (the entire chart represents only 4.5 miles on each axis), but very high intensities. Chart source: DNA 1251-2-EX. Collapsed cloud picture source: Library of Congress.

It was also something of the real birth of “atomic kitsch.” There are some examples from before Crossroads, but there is just a real flourishing afterwards. It seems to have taken a year or so after Hiroshima and Nagasaki for enough time to have passed for Americans to start to regard nuclear weapons entirely frivolously. With Crossroads in particular, a deep connection between sex and death (Freud’s favorites) circled around the bomb. This is where we start to see the sorts of activities that would later result in the “Miss Atomic Bomb” contests, the release of the really kitchy songs, and, of course, the Bikini swimsuit, named after the “atomic bomb island,” as LIFE put it.

The key fulcrum of my article is a meditation on the “crossroads” metaphor, and I should probably note that it was, to some degree, intentional. Vice Admiral William Blandy was reported by the New York Times to have told Congress, that the name was chosen for its “possible significance,” which the Times writer interpreted to mean “that seapower, airpower, and perhaps humanity itself — were at the crossroads.”3

An unusual color (but not colorized!) photograph of the Crossroads Baker detonation, from LIFE magazine. Source.

An unusual color (but not colorized!) photograph of the Crossroads Baker detonation, from LIFE magazine. Source.

What’s interesting to me is that Blandy clearly saw some aspects of the “crossroads,” but there was much he couldn’t have seen — the atomic culture, the arms race, the contamination, the nuclear fears. He knew that “crossroads” was a good name for what they were doing, but it was an even better name than he could have known, for both better and worst.


As before, I wanted to take a moment to give some credit/citation information that wasn’t workable into the New Yorker blog post (where space, and thus academic nicety, is constrained).

The best overall source on Crossroads, which I found invaluable, is Jonathan Weisgall’s Operation Crossroads: The Atomic Tests at Bikini Atoll (Naval Institute Press, 1994). Weisgall has been a legal counsel on behalf of the Marshallese, and his book is just a wealth of information. I was pleased to find a few things that he didn’t have in his book, because it’s a really tough challenge given how much work he put into it. If you find Crossroads interesting, you have to read Weisgall.

Rita Hayworth on the Crossroads Able bomb, "Gilda." Photo by Los Alamos National Laboratory, via Peter Kuran and Bill Geerhart.

Rita Hayworth on the Crossroads Able bomb, “Gilda.” Photo courtesy Los Alamos National Laboratory, via Peter Kuran and Bill Geerhart.

Bill Geerhart, who writes the excellent blog CONELRAD Adjacent (and is the one behind the Atomic Platters series of Cold War songs), has done some really wonderful work on the cultural aspects of Crossroads over the years. His posts on the mushroom cloud cake, and his sleuthing regarding the Rita Hayworth connection, are amazing and worth reading in their entirety. Peter Kuran, the visual effects wizard who made the documentary Trinity and Beyond, among other films and works, was very helpful in providing recently-declassified imagery of the Crossroads bombs, including photos (which I first saw on Geerhart’s blog) of the Rita Hayworth image on the side of the bomb themselves. (I will be writing more about Kuran and his work in the near future…)

Holly Barker’s Bravo for the Marshallese (Thomson/Wadsworth, 2004), is immensely useful as an anthropologist’s view of the Marshallese people and their experiences after the test. My invocation of the Marshallese language for birth defects comes directly from Barker’s book, pages 81 and 106-107. It is a powerful, disturbing section of the book.

Selection from Life magazine's coverage of Crossroads — two visions of the animal testing. Source.

Selection from Life magazine’s coverage of Crossroads — two visions of the animal testing. Source.

Most of the information I got about the Soviet view of Crossroads comes from the multi-volume Atomniy Proekt SSSR document series released by the Russian Federation. I had the full set of these before it was cool, but now Rosatom has put them all online. Scholars have been picking over these for awhile (I have written on them once before), I haven’t seen anybody use the particular documents relating to Crossroads before, but you in Tom (Volume) 2, Kniga (Book) 6, the documents I found most useful were 44 (pp. 130-132), 48 (135-136), 50 (137), 76 (184-188), and 106 (246-248). They show the picking of the delegation of observers, brief biographies of the observers, a summary of Meshcheryakov’s report (his full 110-page report on Crossroads is not included), and some later aspects of Meshcheryakov’s involvement with the planning of the first Soviet nuclear test in 1949 (in which his Bikini experience was offered up as his bonafides).

The other really unusual little source I used for my article is the letter from Percy Bridgman. The letter was sent from Bridgman to Hans Bethe, who relayed it to Norris Bradbury at Los Alamos, who sent it to General Groves. You can read it here. I have been sitting on it for a long time — I almost wrote a blog post about it in 2012, but decided not to for whatever reason. When I worked at the American Institute of Physics I had an opportunity to poke around Bridgman’s life and writings a bit, and he’s really an interesting character. He was the one at Harvard who served as J. Robert Oppenheimer’s physics advisor, and his own work on high-pressure physics not only won him the Nobel Prize of 1946 (which is a nice coincidence for the Crossroads article), but also was used (and is still classified, as far as I can tell) on the Manhattan Project (they seem to have sent him plutonium samples, so you can imagine the kind of work he was doing and why it might still be classified — almost everything on plutonium under high pressures is classified in the United States).

Percy W. Bridgman (L) talking with Harvard colleague (and future Trinity test director) Kenneth Bainbridge, 1934. Source: Emilio Segrè Visual Archives, American Institute of Physics

Percy W. Bridgman (L) talking with Harvard colleague (and future Trinity test director) Kenneth Bainbridge on a Massachusetts beach, 1934. Source: Emilio Segrè Visual Archives, American Institute of Physics.

Bridgman gave a number of talks associated with his Nobel Prize that really tried to get at the heart of what the effects of World War II would be for physics as a discipline. He was very much afraid that Big Science (which hadn’t yet been given that name) would really destroy work like his own, which he saw as small-scale, individual, and not focused on particular applications. He was also very interested in topics related to the philosophy of science, something that a lot of modern-day practicing physicists openly disdain. His Wikipedia page gives a nice, brief overview of his life, and even touches on the poignant circumstances of his death.4.

Notes
  1. This is discussed at length in Jonathan Weisgall’s Operation Crossroads, pp. 201-204.
  2. The account of the security officer is Charles I. Campbell, A Questing Life: The Search for Meaning (New York: iUniverse, 2006). This appears to be a self-published memoir, the sort of thing one would never run across without Google Books. On Aleksandrov’s Gulag connections (which seem plausible given his uranium connections), see this page on his Hero of Socialist Labor award. One of the few English-language articles on Meshcheryakov is available here.
  3. Sidney Shallet, “Test Atomic Bombs to Blast 100 Ships at Marshall Atoll,” New York Times (25 January 1946), 1. Blandy’s full quote on the name from the testimony: “The schedule of target dates for this operation, which will be known by the code word ‘CROSSROADS’—and I would like to explain that we have chosen that merely for brevity in dispatches and other communications, and we chose it with an eye to its possible significance—now calls for the first test to be accomplished early in May, over target ships at an altitude of several hundred feed.” A lot of the sources about Crossroads include Shallet’s bit about “perhaps humanity itself” as a quote of Blandy’s, but it’s not in the transcript that I can see. Hearing before the Special Committee on Atomic Energy, United States Senate, Pursuant to S. Res. 179, Part 4, 79th Congress, 2nd Session (24 January 1946), on 457.
  4. The citation for the Bridgman letter is: Percy W. Bridgman to Hans Bethe, forwarded by Norris Bradbury to Leslie Groves via TWX (13 March 1946), copy in the Nuclear Testing Archive, Las Vegas, NV, document NV0128609.

The blue flash

This last weekend was the 70th anniversary of Louis Slotin’s criticality accident. One slip of a screwdriver; a blue flash and wave of heat; and Slotin had a little over a week to live. It’s a dramatic story, one that has been told before. I tried to give it a little bit of a fresh look in my latest piece for the New Yorker’s Elements Blog: “The Demon Core and the Strange Death of Louis Slotin.”1

Demon Core New Yorker Screenshot

In researching the piece, I looked over a lot of technical literature on the accident, as well as numerous accounts from others who were in the room at the time. A few things stuck out to me that didn’t make it into the piece. One was that it was remarkably non-secret for the time. Los Alamos put out a press release almost immediately after it happened (by May 25th, five days before Slotin’s death, it was in national newspapers), and followed it up with more after Slotin’s death. For mid-1946, when the Atomic Energy Act had not yet been signed and the future of the American nuclear infrastructure was still very much in question, it was remarkably transparent. The press release was where I saw the phrase “three-dimensional sunburn” for the first time.

I also went over the account of Slotin’s case that was published in The Annals of Internal Medicine in 1952.2 Slotin isn’t named, but he’s clearly “Case 3.” Harry Daghlian, who also died from an accident with the same core, is “Case 1,” and Alvin Graves, who was the nearest person to Slotin during his accident, and later became a director of US nuclear weapons testing, is “Case 2.” The article is long and technical, and ends with some of the most disturbing photographs I have ever seen of the Daghlian and Slotin accidents. There is a photo of Daghlian’s hand that has been reproduced many places (including in Rachel Fermi’s Picturing the Bomb), but I’d only previously seen it in black and white. It is much worse in color — the contrast between the white blistered skin and the pink-red stuff under the cut-away area is dramatic and disturbing. There are others in the same series that are just as bad if not worse: blackened, gangrenous fingers. Slotin’s photos in that article are comparatively tame but still pretty unsettling. Blisters. Cyanotic tissue. A photograph of his left hand — the one that was closest to the reacting core — on the ninth day of treatment (his last day alive) looks almost corpselike, or even claw-like. It is unsettling. I will not post it here.

An anonymous e-mail tipped me off that there were more photographs, and more documents, at a collection at the New York Public Library. These were part of a collection deposited by Paul Mullin, who authored the Louis Slotin Sonata, a very interesting, very curious play about Slotin from the late 1990s. I haven’t seen the play, though I had seen mentions of it for awhile. Mullin’s materials were fascinating and very useful. There were two boxes. The first was mostly notes relating to the creation of the play. It is always interesting to see how another researcher takes notes, much less one whose end-product (a play) is very different from the sort of thing I do. It does not take much glancing at his notes to see that Mullin got as deep into this topic as anyone has. The second box contained research materials: four folders of documents obtained from Los Alamos under the Freedom of Information Act, and a folder of photographs.

The hands of Louis Slotin, shortly after admission to the Los Alamos hospital. Source: Los Alamos National Laboratory, via the New York Public Library (Paul Mullin papers on the Louis Slotin Sonata).

The hands of Louis Slotin, shortly after admission to the Los Alamos hospital. Source: Los Alamos National Laboratory, via the New York Public Library (Paul Mullin papers on the Louis Slotin Sonata).

The photographs were, well, terrible. They included the ones from the Annals of Internal Medicine article, but also many more. Some showed Slotin naked, posing with his injuries. The look on his face was tolerant. There were a few more of his hand injuries, and then the time skips: internal organs, removed for autopsy. Heart, lungs, intestines, each arranged cleanly and clinically. But it’s jarring to see photographs of him on the bed, unwell but alive, and then in the next frame, his heart, neatly prepared. The photo above, of just his hands, is one of the tamest of the bunch, though in some sense, one of the saddest (there is a helplessness, almost like begging, in the position). I didn’t make copies of the really awful ones. History is often very voyeuristic — I joke with students that I read dead people’s mail for a living — but, as I commiserated with Mullin over Twitter, at some point you start to almost feel complicit, as silly as that notion is.

The documents were invaluable. They mostly covered the period immediately after the accident — people checking in on Slotin’s health, the complicated legal aspects of dealing with the death of a scientist (and with his distraught family), the questions of what to do next. An inordinate amount of paperwork was generated in dealing with the disposition of Slotin’s automobile (a 1942 Dodge Custom Convertible Coupe). The Army’s interactions with Slotin’s family appeared sympathetic and generous. There appears to have been no cloak-and-dagger regarding the entire affair. Slotin was, after all, a friend to many of those at Los Alamos, and a key member of their “pit crew.”

One of the accounts that I found most fascinating was that of the security guard, Patrick Cleary, who was in the room when the accident happened. Cleary was there because you don’t just keep a significant proportion of the nation’s fissile material stockpile unguarded. He seems to have understood little about what risks his job entailed, though:

When the accident occurred, I saw the blue glow and felt a heat wave. I knew something was wrong, but didn’t know exactly what it was, when I saw the blue glow and somebody yelled. … Our instructions are also to keep in sight of all active material that is around, except in the case of a critical assembly, but [I] am not sure about that. I did not actually know what the material or sphere was at the time, or anything about it.3

When Cleary saw the flash and heard yelling, he literally took off for the hills, running. He was called back, as the scientists tried to reconstruct where people were standing for the purposes of dosage calculation. Cleary, in fact, was the last person to leave, because security guards can’t walk off the job — he had to wait until a replacement came.

Close-in shot on the Slotin accident re-creation. The beryllium tamper is on top; the plutonium core is the smaller sphere in the center. Notice in this particular shot, they have a "shim" on the right. Slotin removed the shim right before his fatal slip.

Close-in shot on the Slotin accident re-creation. The beryllium tamper/reflector (they called it a tamper) is on top; the plutonium core is the smaller sphere in the center. Notice in this particular shot, they have a “shim” on the right. Slotin removed the shim right before his fatal slip. The scientist re-creating the photograph is physicist Chris Wright. I wonder if they took extra precautions in making this particular set of photos?

For a long time I had been wondering what happened to the so-called “demon core,” which was also known as “Rufus,” something that strikes me as just too strange to be anything but true. It has been reported many times that it was used at Operation Crossroads, at the Able shot. I found some documentation that suggested this was very unlikely. For example, shortly after the accident (Slotin was still alive), lab directory Norris Bradbury wrote to a few other scientists at Los Alamos about how the accident had affected the forthcoming Crossroads tests. He notes that the sphere in question was getting “its final check” during the accident — so it was definitely slated for Crossroads. But he continues:

Obviously Slotin will not come to Bikini. [Raemer] Schreiber will come although the date of special shipment was postponed one week to allow us to pull ourselves together. Only two shipments will be made at this time as I see no courier for the third. The sphere in question is OK although still a little hot but not too hot to handle. We will save it for the last in any event if it is needed at all.4

Which seemed pretty suggestive to me that they weren’t going to use it: only two shipments were going to be made early on, and “the sphere in question” was not one of them. It would be saved for the “last event.” Which in this case was the “Charlie” shot — which was cancelled.

I wanted some more confirmation, though, because a plan isn’t always a reality. I e-mailed John Coster-Mullen, who I knew had done a lot of research into the Slotin and Daghlian accidents. (John is the one that provided me with these wonderful high-resolution photographs of the Slotin re-enactment, and some of the documents in his appendices to Atom Bombs were very useful for this research.) John suggested I get in touch with Glenn McDuff, a retired scientist at Los Alamos who was also one of the consultants on Manhattan (he drew the equations on the chalkboards, among other things). This turned out to be a great tip: Glenn has been working on an article about the fate of the first eight cores. There is much still to be declassified, but he was able to share with me the fate of the core in question: it had not been used at Crossroads, it had been melted down and the material re-used in another core. Glenn says there was no particular reason it was melted down. It was old, as far as cores went, and they were constantly fiddling with them in those days — the days in which they still gave bomb cores individual nicknames, because there were so few of them.

For nuke nerds, this is the big “reveal” of my New Yorker piece, the one thing that even someone very steeped in Los Alamos history probably doesn’t know. (For non-nuke nerds, I doubt it registers as much!) And even though it is a bit anticlimactic, I actually prefer it to the version that the core was detonated shortly after the accident. The part about them immediately re-using the core in a weapon just always seemed a little suspicious to me — it almost implied that they had done it due to superstition, and that didn’t really jibe with my sense of how these scientists viewed the accident or these weapons. And even the anticlimax has a bit of a literary touch to it: the “demon core” wasn’t expended in a flash, it was melted down and reintegrated with the stockpile. Who knows whether bits of its plutonium ended up in other weapons over the years, whether any of that core is still with us in the current arsenal? There’s perhaps something even a bit more “demonic” about this version of the story.

Notes
  1. A few small errata to the piece, based on a few questions I got: 1. Should the beryllium hemisphere be called a tamper or a reflector? In most contexts today we would call it a neutron reflector, because that’s the property that you use beryllium for in a bomb (a tamper’s job, generally, is to hold the core together as long as possible while it reacts, and so heavy, dense metals like uranium are used). But in this case, the scientists at the time referred to it universally as a “beryllium tamper” so the editor and I just decided to keep things simple and call it that, rather than call it a “reflector” and then clarify that it was the same thing as the “tamper” that was cited in the quotes. (This is the kind of linguistic hair-splitting that goes into these pieces — a balance between the historical language, the present-day language, the technical aspects, etc. We try to come to sensible decisions.) 2. At one point, it refers to the “pits” at Hiroshima and Nagasaki. This is just meant in a colloquial way here to refer to their fissile material cores. The Hiroshima bomb of course was a different design, made of two different pieces, called the Projectile and the Target in the documents at the time. It seemed unnecessary to introduce all that complexity to make a point that they didn’t give it any kind of colorful moniker. 3. There was one legitimate typo in the piece as published, which was my fault. It misstated the amount of time between the Daghlian and Slotin accidents (three months instead of nine). I’m not sure how that got in there — I actually re-looked up the date differences at the time I wrote it, and know the months cold. One of those strange disconnects between the head and the fingers, I suppose, and somehow I missed it in re-reading the drafts. Very frustrating! It’s the little things you aren’t worried about getting wrong that can get you, in the end. It has been fixed.
  2. Louis H. Hempelmann, Hermann Lisco, and Joseph G. Hoffmann, “The Acute Radiation Syndrome: A Study of Nine Cases and a Review of the Problem,” Annals of Internal Medicine 36, no. 2 (February 1952), Part 1, 279-510.
  3. Patrick Cleary, account of the Slotin accident (29 May 1946). Copy in the Paul Mullin, “Production materials for the Louis Slotin Sonata, 1946-2006,” New York Public Library.
  4. Norris Bradbury to Marshall Holloway and Roger Warner (undated, ca. 24-29 May 1946). Copy in the Paul Mullin, “Production materials for the Louis Slotin Sonata, 1946-2006,” New York Public Library.