Posts Tagged ‘1940s’

Visions

Operation Crossroads at 70

Monday, July 25th, 2016

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. []
Meditations

A brief history of the nuclear triad

Friday, July 15th, 2016

Summers for me are paradoxically the time I can get work done, and the time in which I feel I have the most work. I’m not teaching, which in theory means I have much more unstructured time. The consequence, though, is that I have about a million projects I am trying to get done in what is still a limited amount of time, and I’m also trying to see family, friends, and get a little rest. I sort of took June off from blogging (which I felt was my due after the amount of exposure I got in April and May), but I have several posts “in the hopper,” and several other things coming out soon. Yesterday I gave a talk at the US Department of State as part of their Timbie Forum (what used to be called their Generation Prague conference). I was tasked with providing the historical background on the US nuclear “triad,” as part of a panel discussion of the future of the triad. This is subject-matter I’ve taught before, so I felt pretty comfortable with it, but I thought I would return to a few of my favorite sources and refresh my understanding. This post is something of a write-up of my notes — more than I could say in a 20-minute talk.

There is a lot of buzzing about lately about the future of the United States’ “nuclear triad.” The triad is the strategic reliance on three specific delivery “platforms” for deterrence: manned-bombers (the B-2 and the B-52), long-range intercontinental ballistic missiles (ICBMs; specifically the Minuteman III), and submarine-launched ballistic missiles (SLBMs; specifically the Trident II missile carried by Ohio class submarines). Do we need all three “legs” of the triad? I don’t know — that’s a question for another day, and depends on how you balance the specific benefits and risks of each “leg” with the costs of maintaining or upgrading them. But as we think about the future of the US arsenal, looking at how the triad situation came about, and how people started talking about it as a “triad,” offers some interesting food for thought.

The modern nuclear triad. Source: Nuclear Posture Review, 2010.

The modern nuclear triad. Source: Nuclear Posture Review, 2010.

The stated logic of the triad has long as such: 1) bombers are flexible in terms of their armaments and deployments (and have non-nuclear roles); 2) ICBM forces are kept far from the enemy, are highly-accurate, and thus make a first-strike attack require a huge amount of “investment” to contemplate; 3) SLBM forces are, for the near term, capable of being kept completely hidden from attack, and thus are a guaranteed “second strike” capability. The combination of these three factors, the logic goes, keeps anyone from thinking they could get away with a nuclear attack.

That’s the rationale. It’s not the history of it, though. Like so many things, the history is rather wooly, full of stops-and-starts, and a spaghetti graph of different organizations, initiatives, committees, industrial contractors, and ideas. I have tried to summarize a lot of material below — with an idea to pointing out how each “leg” of the triad got (or did not get, depending on when) the support it needed to become a reality. I only take these histories up through about 1960, after which each of the three “legs” were deployed (and to try and go much further would result in an even-longer post).

LEG 1: MANNED BOMBERS

The United States’ first approach to the “delivery” question was manned, long-range bombers. Starting with the B-29, which delivered the first atomic bombs, and some 80 million pounds of incendiaries, over Japanese cities during World War II, the US was deeply committed to the use of aircraft as the means of getting the weapons from “here” to “there.” Arguably, this commitment was a bit overextended. Bureaucratic and human factors led to what might be called a US obsession with the bomber. The officers who rose through the ranks of the US Army Air Forces, and the newly-created (in 1947) US Air Force, were primarily bomber men. They came out of a culture that saw pilots as the ultimate embodiment of military prowess. There were some exceptions, but they were rare.

The B-29's power was more than military — it became a symbol of a new form of warfare for the generals of the newly-constituted US Air Force. Source.

The B-29’s power was more than military — it became a symbol of a new form of warfare for the generals of the newly-constituted US Air Force. Source.

In their defense, the US had two major advantages over the Soviet Union with respect to bombers. The first is that the US had a lot more experience building them: the B-29 “Superfortress” was an impressive piece of machinery, capable of flying further, faster, and with a higher load of armaments than anything else in the world at the time, and it was just the beginning.

The second was geography. The B-29 had a lot of range, but it wasn’t intercontinental. With a range of some 3,250 miles, it could go pretty far: from the Marianas to anywhere in Japan and back, for example. But it couldn’t fly a bomb-load to Moscow from the United States (not even from Alaska, which was only in range of the eastern half of Russia). This might not look like an advantage, but consider that this same isolation made it very hard for the Soviet Union to use bombers to threaten the United States in the near-term, and that the US had something that the USSR did not: lots of friends near its enemy’s borders.

As early as late August 1945, the United States military planners were contemplating how they could use friendly airfields — some already under US control, some not — to put a ring around the Soviet Union, and to knock it out of commission if need be. In practice, it took several years for this to happen. Deployments of non-nuclear components of nuclear weapons abroad waited until 1948, during the Berlin Blockade, and the early stages of the Korean War.

US nuclear bomber deployments, 1945-1958. One of my favorite slides that I use when teaching — it shows what "containment" comes to mean, and amply demonstrates the geopolitics of Cold War bomber bases.

US nuclear bomber deployments, 1945-1958. One of my favorite slides that I use when teaching — it shows what “containment” comes to mean, and amply demonstrates the geopolitics of Cold War bomber bases. Shadings indicate allies/blocs circa 1958.

In 1951, President Truman authorized small numbers of nuclear weapons (with fissile cores) to be deployed to Guam. But starting in 1954, American nuclear weapons began to be dispersed all-around the Soviet perimeter: French Morocco, Okinawa, and the United Kingdom in 1954; West Germany in 1955; Iwo Jima, Italy, and the Philippines in 1957; and France, Greenland, Spain, South Korea, Taiwan, and Tunisia in 1958. This was “containment” made real, all the more so as the USSR had no similar options in the Western Hemisphere until the Cuban Revolution. (And as my students always remark, this map puts the Cuban Missile Crisis into perspective.)1

And if the B-29 had been impressive, later bombers were even more so. The B-36 held even more promise. Its development had started during World War II, and its ability to extend the United States’ nuclear reach was anticipated as early as 1945. It didn’t end up being deployed until 1948, but added over 700 miles to the range of US strategic forces, and could carry some 50,000 lbs more fuel and armament. The B-52 bomber, still in service, was ready for service by 1955, and extended the range of bombers by another several hundred miles, increased the maximum flight speed by more than 200 miles per hour.2

Plane First flight Introduced in service Combat range (mi) Maximum speed (mph) Service ceiling (ft) Bomb weight (lbs)
B-17 1935 1938 2,000 287 35,600 4,500
B-29 1942 1944  3,250 357  31,850  20,000
B-36 1946 1948  3,985 435  43,000  72,000
B-52 1952 1955  4,480 650  50,000  70,000
B-2 1989 1997  6,000 630  50,000  40,000

So you can see, in a sense, why the US Air Force was so focused on bombers. They worked, they held uniquely American advantages, and you could see how incremental improvement would make them fly faster, farther, and with more weight than before. But there were more than just technical considerations in mind: fascination with the bomber was also cultural. It was also about the implied role of skill and value of control in a human-driven weapon, and it was also about the idea of “brave men” who fly into the face of danger. The bomber pilot was still a “warrior” in the traditional sense, even if his steed was a complicated metal tube flying several miles above the Earth.

LEG 2: LAND-BASED INTERCONTINENTAL BALLISTIC MISSILES (ICBMs)

But it wasn’t just that the USAF was pro-bomber. They were distinctly anti-missile for a long time. Why? The late Thomas Hughes, in his history of Project Atlas, attributes a distinct “conservative momentum, or inertia” to the USAF’s approach to missiles. Long-range missiles would be disruptive to the hierarchy: engineers and scientists would be on top, with no role for pilots in sight. Officers would, in a sense, become de-skilled. And perhaps there was just something not very sporting about lobbing nukes at another country from the other side of the Earth.3

But, to be fair, it wasn’t just the Air Force generals. The scientists of the mid-1940s were not enthusiastic, either. Vannevar Bush told Congress in 1945 that:

There has been a great deal said about a 3,000 mile high-angle rocket. In my opinion such a thing is impossible and will be impossible for many years. The people who have been writing these things that annoy me have been talking about a 3,000 mile high-angle rocket shot from one continent to another carrying an atomic bomb, and so directed as to be a precise weapon which would land on a certain target such as this city. I say technically I don’t think anybody in the world knows how to do such a thing, and I feel confident it will not be done for a very long time to come.

Small amounts of money had been doled out to long-range rocket research as early as 1946. The Germans, of course, had done a lot of pioneering work on medium-range missiles, and their experts were duly acquired and re-purposed as part of Operation Paperclip. The Air Force had some interest in missiles, though initially the ones they were more enthusiastic about were what we would call cruise missiles today: planes without pilots. Long-range ballistic missiles were very low on the priority list. As late as 1949 the National Security Council gave ballistic missiles no research priority going forward — bombers got all of it.

Soviet testing of an R-1 (V-2 derivative) rocket at Kapustin Yar. Soviet rocket tests were detected by American radars — and spurred US interest in rockets. Source.

Soviet testing of an R-1 (V-2 derivative) rocket at Kapustin Yar. Soviet rocket tests were detected by American radars — and spurred US interest in rockets. Source.

Real interest in ballistic missiles did not begin until 1950, when intelligence reports gave indication of Soviet interest in the area. Even then, the US Air Force was slow to move — they wanted big results with small investment. And the thing is, rocket science is (still) “rocket science”: it’s very hard, all the more so when it’s never been really done before.

As for the Soviets: while the Soviet Union did not entirely forego research into bombers, the same geographic factors as before encouraged them to look into long-range rockets much earlier than the United States. For the USSR to threaten the USA with bombers would require developing very long-range bombers (because they lacked the ability to put bases on the US perimeter), and contending with the possibility of US early-warning systems and interceptor aircraft. If they could “skip” that phase of things, and jump right to ICBMs, all the better for them. Consequently, Stalin had made missile development a top priority as early as 1946.

It wasn’t until the development of the hydrogen bomb that things started to really change in the United States. With yields in the megaton range, suddenly it didn’t seem to matter as much if you couldn’t get the accuracy that high. You can miss by a lot with a megaton and still destroy a given target. Two American scientists played a big role here in shifting the Air Force’s attitude: Edward Teller and John von Neumann. Both were hawks, both were H-bomb aficionados, and both commanded immense respect from the top Air Force brass. (Unlike, say, J. Robert Oppenheimer, who was pushing instead for tactical weapons that could be wielded by the — gasp — Army.)

Ivy Mike, November 1952. Accuracy becomes less of a problem.

Ivy Mike, November 1952. Accuracy becomes less of a problem.

Teller and von Neumann told the Air Force science board that the time had come to start thinking about long-range missiles — that in the near term, you could fit a 1-2 megatons of explosive power into a 1-ton warhead. This was still pretty ambitious. The US had only just tested its first warhead prototype, Ivy Mike, which was an 80-ton experiment. They had some other designs on the books, but even the smaller weapons tested as part of Operation Castle in 1954 were multi-ton. But it was now very imaginable that further warhead progress would make up that difference. (And, indeed, by 1958 the W49 warhead managed to squeeze 1.44 Mt of blast power into under 1-ton of weight — a yield-to-weight ratio of 1.9 kt/kg.)

The USAF set up an advisory board, headed by von Neumann, with Teller, Hans Bethe, Norris Bradbury, and Herbert York on it. The von Neumann committee concluded that long-range missile development needed to be given higher priority in 1953. Finally, the Department of Defense initiated a full-scale ICBM program — Project Atlas — in 1954.

Even this apparent breakthrough of bureaucratic inertia took some time to really get under way. You can’t just call up a new weapons system from nothing by sheer will alone. As Hughes explains, there were severe doubts about how one might organize such a work. The first instinct of the military was to just order it up the way they would order up a new plane model. But the amount of revolutionary work was too great, and the scientists and advisors running the effort really feared that if you went to a big airplane company like Convair and said, “make me a rocket,” the odds that they’d actually be able to make it work were low. They also didn’t want to assign it to some new laboratory run by the government, which they felt would be unlikely to be able to handle the large-scale production issues. Instead, they sought a different approach: contract out individual “systems” of the missile (guidance, fuel, etc.), and have an overall contractor manage all of the systems. This took some serious effort to get the DOD and Air Force to accept, but in the end they went with it.

Launch sequence of an Atlas-D ICBM, 1960. Source.

Launch sequence of an Atlas-D ICBM, 1960. Source.

Even then things were pretty slow until mid-1954, when Congressional prodding (after they were told that there were serious indications the Soviets were ahead in this area) finally resulted in Atlas given total overriding defense priority. Even then the people in charge of it had to find ways to shortcut around the massive bureaucracy that had grown up around the USAF and DOD contracting policies. In Hughes’ telling of Atlas, it is kind of amazing that it gone done at rapidly as it did — it seems that there were near-endless internal obstacles to get past.  The main problem, one Air Force historian opined, was not technical: “The hurdle which had to be annihilated in correcting this misunderstanding was not a sound barrier, or a thermal barrier, but rather a mental barrier, which is really the only type that man is ever confronted with anyway.” According to one estimate, the various long-term cultural foot-dragging about ballistic missiles in the United States delayed the country from acquiring the technology for six years. Which puts Sputnik into perspective.

The US would start several different ballistic missile programs in the 1950s:

Rocket family Design started Role Military patron Prime industrial contractor Warhead yield
Redstone 1950 IRBM US Army Chrysler 0.5-3.5 Mt
Atlas 1953 ICBM USAF Convair 1.44 Mt
Thor 1954 IRBM USAF Douglas 1.4 Mt
Titan 1955 ICBM USAF Glenn Martin 3.75 Mt
Polaris 1956 SLBM USN Lockheed 0.6 Mt
Minuteman 1957 ICBM USAF Boeing 1.2 Mt

As you can see, there’s some redundancy there. It was deliberate: Titan, for example, was a backup to Atlas in case it didn’t work out. There’s also some interesting stuff going on with regards to other services (Army, Navy) not wanting to be “left out.” More on that in a moment. Minuteman, notably, was based on solid fuel, not liquid, giving it different strategic characteristics, and a late addition. The Thor and Redstone projects were for intermediate-range ballistic missiles (IRBMs), not ICBMs — they were missiles you’d have to station closer to the enemy than the continental United States (e.g., the famous Jupiter missiles kept in Turkey).

The redundancy was a hedge: the goal was to pick the top two of the programs and cancel the rest. Instead, Sputnik happened. In the resulting political environment, Eisenhower felt he had to put into production and deployment all six of them — even though some were demonstrably not as technically sound as others (Thor and Polaris, in their first incarnations, were fraught with major technical problems). This feeling that he was pushed by the times (and by Congress, and the services, and so on) towards an increasingly foolish level of weapons production is part of what is reflected in Eisenhower’s famous 1961 warning about the powerful force of the “military-industrial complex.”4

LEG 3: SUBMARINE-LAUNCHED BALLISTIC MISSILES (SLBMs)

Polaris is a special and interesting case, because it’s the only one in that list that is legitimately a different form of delivery. Shooting a ballistic missile is hard enough; shooting one from a submarine platform was understandably more so. Today the rationale of the SLBM seems rather obvious: submarines have great mobility, can remain hidden underwater even at time of launch, and in principle seem practically “invulnerable” — the ultimate “second strike” guarantee. At the time they were proposed, though, they were anything but an obvious approach: the technical capabilities just weren’t there. As already discussed at length, even ICBMs were seen with a jaundiced eye by the Air Force in the 1950s. Putting what was essentially an ICBM on a boat wasn’t going to be something the Air force was going to get behind. Graham Spinardi’s From Polaris to Trident is an excellent, balanced discussion the technical and social forces that led to the SLBM becoming a key leg of the “triad.”5

The USS Tunny launches a cruise missile (Regulus) circa 1956. Source.

The USS Tunny launches a cruise missile (Regulus) circa 1956. Source.

The Navy had in fact been interested in missile technology since the end of World War II, getting involved in the exploitation of German V-2 technology by launching one from an aircraft carrier in 1947. But they were also shy of spending huge funds on untested, unproven technology. Like the Air Force, they were initially more interested in cruise than ballistic missiles. Pilotless aircraft didn’t seem too different from piloted aircraft, and the idea of carrying highly-volatile liquid fueled missiles made Navy captains squirm. The Regulus missile (research started in 1948, and fielded in 1955) was the sort of thing they were willing to look at: a nuclear-armed cruise missile that could be launched from a boat, with a range of 575 miles. They were also very interested in specifically-naval weapons, like nuclear-tipped torpedoes and depth charges.

What changed? As with the USAF, 1954 proved a pivotal year, after the development of the H-bomb, the von Neumann committee’s recommendations, and fears of Soviet work combined with a few other technical changes (e.g., improvements in solid-fueled missiles, which reduced the fear of onboard explosions and fires). The same committees that ended up accelerating American ICBM work similarly ended up promoting Naval SLBM work as well, as the few SLBM advocates in the Navy were able to use them to make a run-around of the traditional authority. At one point, a top admiral cancelled the entire program, but only after another part of the Navy had sent around solicitations to aerospace companies and laboratories for comment, and the comments proved enthusiastic-enough that they cancelled the cancellation.

As with the ICBM, there was continued opposition from top brass about developing this new weapon. The technological risks were high: it would take a lot of money and effort to see if it worked, and if it didn’t, you couldn’t get that investment back. What drove them to finally push for it was a perception of being left out. The Eisenhower administration decided in 1955 that only four major ballistic missile programs would be funded: Atlas, Titan, Thor, and Redstone. The Navy would require partnering up with either the USAF or US Army if it wanted any part of that pie. The USAF had no need of it (and rejected an idea for a ship-based Thor missile), but the Army was willing to play ball. The initial plan was to develop a ship-based Jupiter missile (part of the Redstone missile family), with the original schedule was to have one that could be fielded by 1965.

But the Navy quickly was dissatisfied with Jupiter’s adaptability to sea. It would have to be shrunk dramatically to fit onto a submarine, and the liquid-fuel raised huge safety concerns. They quickly started modifying the requirements, producing a smaller, solid-fueled intermediate-range missile. They were able to convince the Army that this was a “back-up” to the original Jupiter program, so it would technically not look like a new ballistic missile program. Even so, it was an awkward fit: even the modified Jupiter’s were too large and bulky for the Navy’s plans.

What led to an entirely new direction was a fortuitous meeting between a top naval scientist and Edward Teller (who else?), at a conference on anti-submarine warfare in the summer of 1956. At the conference, Teller suggested that trends in warhead technology meant that by the early 1960s the United States would be able to field megaton-range weapons inside a physics package that could fit into small, ship-based missiles. Other weapons scientists regarded this as possibly dangerous over-hyping and over-selling of the technology, but the Navy was convinced that they could probably get within the right neighborhood of yield-to-weight ratios. By the fall of 1956, the Navy had approved a plan to create their own ballistic missile with an entirely different envelope and guidance system than Jupiter, and so Polaris was born.

Artist's conception of a Polaris missile launch. Source.

Artist’s conception of a Polaris missile launch. Source.

The first generation of Polaris (A-1) didn’t quite meet the goals articulated in 1956, but it got close. Instead of a megaton, it was 600 kilotons. Instead of 1,500 mile range, it was 1,200. These differences matter, strategically: there was really only one place it could be (off the coast of Norway) if it wanted to hit any of the big Soviet cities. And entirely separately, the first generation of Polaris warheads were, to put it mildly, a flop. They used an awful lot of fissile material, and there were fears of criticality accidents in the event of an accidental detonation. No problem, said the weapons designers: they’d put a neutron-absorbing strip of cadmium tape in the core of the warhead, so that if the high explosives were ever to detonate, no chain reaction would be possible. Right before any intended use, a motor would withdraw the tape. Sounds good, right? Except in 1963, it was discovered that the tape corroded while inside the cores. It was estimated that 75% of the warheads would not have detonated: the mechanism would have snapped the tape, which would then have been stuck inside the warhead. There was, as Eric Schlosser, in Command and Control, quotes a Navy officer concluding that they had “almost zero confidence that the warhead would work as intended.” They all had to be replaced.6

The first generation of Polaris missiles, fielded in 1960, were inaccurate and short-ranged (separate from the fact that the warheads wouldn’t have worked). This relegated them to a funny strategic position. They could only be used as a counter-value secondary-strike: they didn’t have the accuracy necessary to destroy hardened targets, and many of those were more centrally-located in the USSR.

WHEN AND WHY DO WE TALK ABOUT A TRIAD?

The “triad” was fielded starting in the 1960s. But there was little discussion of it as a “triad” per se: it was a collection of different weapon systems. Indeed, deciding that the US strategic forces were really concentrated into just three forces is a bit of an arbitrary notion, especially during the Cold War but even today. Where do foreign-based IRBMs fit into the “triad” concept? What about strategic weapons that can be carried on planes smaller than heavy bombers? What about the deterrence roles of tactical weapons, the nuclear artillery shells, torpedoes, and the itty-bitty bombs? And, importantly, what about the cruise missiles, which have developed into weapons that can be deployed from multiple platforms?

Nuclear Triad Google Ngram

Relative word frequency for “nuclear triad” as measured across the Google Books corpus. Source.

 

It’s become a bit cliché in history circles to pull up Google Ngrams whenever we want to talk about a concept, the professorial equivalent of the undergraduate’s introductory paragraph quoting from the dictionary. But it’s a useful tool for thinking about when various concepts “took hold” and their relative “currency” over time. What is interesting in the above graph is that the “triad” language seems to surface primarily in the 1970s, gets huge boosts in the late Cold War, and then slowly dips after the end of the Cold War, into the 21st century.

Which is to say: the language of the “triad” comes well after the various weapon systems have been deployed. It is not the “logic” of why they made the weapons systems in the first place, but a retrospective understanding of their strategic roles. Which is no scandal: it can take time to see the value of various technologies, to understand how they affect things like strategic stability.

But what’s the context of this talk about the triad? If you go into the Google Books entries that power the graph, they are language along the lines of: “we rely on the triad,” “we need the triad,” “we are kept safe by the triad,” and so on. This sort of assertive language is a defense: you don’t need to sing the praises of your weapons unless someone is doubting their utility. The invocation of the “triad” as a unitary strategic concept seems to have come about when people started to wonder whether we actually needed three major delivery systems for strategic weapons.

A strange elaboration of the triad notion from the Defense Logistics Agency, in which the "new triad" includes the "old triad" squished into one "leg," with the other "legs" being even less tangible notions joined by a web of command and control. At this point, I'd argue it might be worth ditching the triad metaphor. Source.

A strange elaboration of the triad notion from the Defense Logistics Agency, in which the “new triad” includes the “old triad” squished into one “leg,” with the other “legs” being even less tangible notions joined by a web of command and control. At this point, I’d argue it might be worth ditching the triad metaphor. Source.

When you give something abstract a name, you aid in the process of reification, making it seem tangible, real, un-abstract. The notion of the “triad” is a concept, a unifying logic of three different technologies, one that asserts quite explicitly that you need all three of them. This isn’t to say that this is done in bad faith, but it’s a rhetorical move nonetheless. What I find interesting about the “triad” concept — and what it leaves out — is that it is ostensibly focused on technologies and strategies, but it seems non-coincidentally to be primarily concerning itself with infrastructure. The triad technologies each require heavy investments in bases, in personnel, in jobs. They aren’t weapons so much as they they are organizations that maintain weapons. Which is probably why you have to defend them: they are expensive.

I don’t personally take a strong stance on whether we need to have ICBMs and bombers and SLBMs — there are very intricate arguments about how these function with regards to the strategic logic of deterrence, whether they provide the value relative to their costs and risks, and so on, that I’m not that interested in getting into the weeds over. But the history interests me for a lot of reasons: it is about how we mobilize concepts (imposing a “self-evident” rationality well after the fact), and it is also about how something that in retrospect seems so obvious to many (the development of missiles, etc.) can seem so un-obvious at the time.

Notes
  1. The list of these deployments comes from the appendices in History of the Custody and Deployment of Nuclear Weapons, July 1945 through September 1977 (8MB PDF here), prepared by the Office of the Assistant to the Secretary of Defense (Atomic Energy), in February 1978, and Robert S. Norris, William Arkin, and William Burr, “Where They Were,” Bulletin of the Atomic Scientists (November/December 1999), 27-35, with a follow-up post on the National Security Archive’s website. []
  2. All of the quantitative data on these bombers was taken from their Wikipedia pages. In places where there were ranges, I tried to pick the most representative/likely numbers. I am not an airplane buff, but I am aware this is the sort of thing that gets debated endlessly on the Internet! []
  3. Thomas Hughes, Rescuing Prometheus: Four Monumental Projects That Changed the Modern World (New York : Pantheon Books, 1998), chapter 3, “Managing a Military Industrial Complex: Atlas,” 69-139. []
  4. Eric Schlosser’s Command and Control has an excellent discussion of the politics of developing the early missile forces. []
  5. Graham Spinardi, From Polaris to Trident: The Development of US Fleet Ballistic Missile Technology (Cambridge University Press, 1994). []
  6. Spinardi, as an aside, gives a nice account of how they eventually achieved the desired yield-to-weight ratio in the W-47: the big “innovation” was to just use high-enriched uranium as the casing of the secondary, instead of unenriched uranium. As he notes, this was the kind of thing that was obvious in retrospect, but wasn’t obvious at the time — it required a different mindset (one much more willing to “expend” fissile material!) than the weapons designers of the early 1950s were used to. []
Meditations

Obama visits Hiroshima

Friday, May 27th, 2016

The big nuclear news this week was President Obama’s visit to Hiroshima. Obama is the first sitting-President to visit the city (Carter and Nixon visited it after their terms were up). The speech he gave is more or less what I thought he was going to say: a short discussion (with heavy reliance on passive voice) on the bombings (they just sort of happened, right?), a vague call to make a world without nuclear weapons and war, a invocation of a lot of standard nuclear age stereotypes (humanity destroying itself, needing to be smart in ways that are not just about making weapons, etc.).

I’m not criticizing the speech — it’s fine, for what it is. There is nothing that the President could really say that would be enormously satisfying, no matter what your position on nuclear weapons is, or what your position is on him as a President. He wasn’t going to apologize for the bombings, he wasn’t going to justify the bombings, he isn’t going to make nuclear weapons (or war) disappear overnight. Such are the realities of our present political discourse and state of the world. I think it’s a good thing that he went. The speech is an exercise in compassion and empathy. That’s never a bad thing. The one thing I would press him on, if I got to do so: he uses the word “we” a lot (e.g., “How easily we learn to justify violence in the name of some higher cause“). Who is this “we”? Is it a narrow “we,” a national “we,” a human “we”? I think the latter — but the danger of using that inclusive a “we” is that it assigns no real responsibility. If he wants the things that he says he does, he needs to narrow down the “we” a bit, to start talking about who, specifically, is going to accomplish those things.

What Presidents Talk About When the Talk About Hiroshima - Screenshot

I was asked if I would write something with a historical slant on it about his visit. It is now up at the New Yorker’s website: “What Presidents Talk about When the Talk About Hiroshima.” I went over every public discussion of Hiroshima or Nagasaki that I could find from US Presidents. By and large, they don’t talk about them much, or if they do, it’s in a very brief and often vague context. Ronald Reagan actually gave an address on its anniversary in 1985 but managed to say really nothing about it; a year later he invoked Hiroshima in defense of the Strategic Defense Initiative. In his farewell address, Jimmy Carter invoked Hiroshima in a rather generic way to talk about the specter of nuclear war. And so on.1

The only two Presidents who spilled much ink on the topic of the history, perhaps not surprisingly, were the two who had the most proximity to the event (aside from Roosevelt, of course, who died before the atomic bomb was non-secret, and left very little record as to his thoughts about its possible use before his death), Harry Truman and Dwight Eisenhower. It’s an interesting pairing in that Truman was, as one would expect, very much interested in making sure the historical record saw his work as justified. He, along with Henry Stimson and Leslie Groves took part in an active campaign to push a specific version of the story, namely the “decision to use the bomb” narrative (in which Truman deliberated and weighed the decision and decided to order the bombing). This version of things is pretty universally rejected by historians today — it just isn’t what happened. There was no single decision to use the bomb, there was no real debate over whether it should be used, and Truman wasn’t that central to any of it. It’s a retrospective narrative made to streamline the issues (e.g. “bomb or invade,” which makes bombing look like the only acceptable answer and obscures any possibility of alternatives), and reinforce a postwar notion about the responsibility of the President (e.g. the bombing as a political decision, not a military one). One can still support the use of the bombs without subscribing to this particular version of the story.

The "Atomic Bomb Dome," before and after the bombing of Hiroshima. I find this particular picture very striking, because without the "before," the extent of the "after" is hard to make sense of. More of these on-the-ground before-and-after photos here, along with the source.

The “Atomic Bomb Dome,” before and after the bombing of Hiroshima. I find this particular picture very striking, because without the “before,” the extent of the “after” is hard to make sense of. More of these on-the-ground before-and-after photos can be found here, along with the source information.

Eisenhower’s views for many will be the more surprising of the two. At various points both before and after (but not during) his Presidency he published some very strongly-worded statements implying that the bombings were morally wrong, unnecessary, and that he had objected to them. These are often marshaled by historians today who want to argue that the bombings weren’t necessary. The thing is, this narrative is really flawed as well. Barton Bernstein did a compelling job (decades ago) in demonstrating that there is no real evidence for Eisenhower’s later accounts of his dissent, and that it is pretty unlikely that things happened the way Eisenhower said they did.2

Today I think we can read Eisenhower’s feelings on the bomb through the lens of how the postwar military viewed the public perception of the atomic bomb having “ended the war” — they were being robbed of the credit for all of the difficult (and destructive) work the conventional forces did. Eisenhower himself is a wonderfully complex figure, with lots of paradoxical positions on nuclear weapons. The nuclear arsenal grew to astounding heights under his watch, the weapons moved into military custody, and the raw megatonnage became frankly incredible (in 1960, the US arsenal had nearly 20,500 megatons worth of weapons in it — some 1.3 million Hiroshima equivalents). Yet he also acutely understood that nuclear war would be disastrous and terrible, and he sought ways out of the nuclear bind (Atoms for Peace being his most notable program in this respect, whatever one thinks of its success). Eisenhower at times felt hemmed-in by his times and context, as his famous farewell address makes quite clear.

The fact that both Truman and Eisenhower had stakes in making their arguments doesn’t mean that their views of history should just be discounted, but neither does their proximity to the event mean their views should get elevated epistemic status (they aren’t necessarily true — and we don’t have to get into whether they were misremembered, were being misleading, etc.). Everyone involved in the end of war had some stakes in thinking one way or another about the role and necessity of the atomic bombs.

I like using Eisenhower’s views (and the other views I mention in the New Yorker piece, like the US Strategic Bombing Survey) not because I think they are correct (my views on the bombings are more complicated than can be described with with “for” or “against” arguments), but because they illustrate that the idea that the bombings weren’t the be-all and end-all of the war is not just a late-Cold War lefty “revisionist” notion. They also point (as I indicate at the end of the New Yorker piece) to the fact that our present-day American political mapping of opinions about the atomic bombings (conservatives in favor, liberals opposed) is not how they were viewed at the time. This helps, I think, to get us out of the trap of thinking that our opinions about these historical events necessarily have to be derived from our present-day politics. The politics of the late 1940s are not the politics of today. If we are serious about the study of history (and I am), we should not expect everything about the past to line up with what we think about the world in the 21st century.

Notes
  1. Side-note: In 1983, Reagan visited Japan and said he wished he had time to visit Hiroshima and Nagasaki, among other cities. This was remarked-upon by the reporters attending, but there was no follow-up. []
  2. Barton Bernstein, “Ike and Hiroshima: Did he oppose it?,” Journal of Strategic Studies 10, no. 3 (1987), 377-389. []
Redactions

The blue flash

Monday, May 23rd, 2016

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. []
Visions

Silhouettes of the bomb

Friday, April 22nd, 2016

You might think of the explosive part of a nuclear weapon as the “weapon” or “bomb,” but in the technical literature it has its own kind of amusingly euphemistic name: the “physics package.” This is the part of the bomb where the “physics” happens — which is to say, where the atoms undergo fission and/or fusion and release energy measured in the tons of TNT equivalent.

Drawing a line between that part of the weapon and the rest of it is, of course, a little arbitrary. External fuzes and bomb fins are not usually considered part of the physics package (the fuzes are part of the “arming, fuzing, and firing” system, in today’s parlance), but they’re of course crucial to the operation of the weapon. We don’t usually consider the warhead and the rocket propellant to be exactly the same thing, but they both have to work if the weapon is going to work. I suspect there are many situations where the line between the “physics package” and the rest of the weapon is a little blurry. But, in general, the distinction seems to be useful for the weapons designers, because it lets them compartmentalize out concerns or responsibilities with regards to use and upkeep.

Physics package silhouettes of some of the early nuclear weapon variants. The Little Boy (Mk-1) and Fat Man (Mk-3) are based on the work of John Coster-Mullen. All silhouette portraits are by me — some are a little impressionistic. None are to any kind of consistent scale.

The shape of nuclear weapons was from the beginning one of the most secret aspects about them. The casing shapes of the Little Boy and Fat Man bombs were not declassified until 1960. This was only partially because of concerns about actual weapons secrets — by the 1950s, the fact that Little Boy was a gun-type weapon and Fat Man was an implosion weapon, and their rough sizes and weights, were well-known. They appear to have been kept secret for so long in part because the US didn’t want to draw too much attention to the bombing of the cities, in part because we didn’t want to annoy or alienate the Japanese.

But these shapes can be quite suggestive. The shapes and sizes put limits on what might be going on inside the weapon, and how it might be arranged. If one could have seen, in the 1940s, the casings of Fat Man and Little Boy, one could pretty easily conjecture about their function. Little Boy definitely has the appearance of a gun-type weapon (long and relatively thin), whereas Fat Man clearly has something else going on with it. If all you knew was that one bomb was much larger and physically rounder than the other, you could probably, if you were a clever weapons scientist, deduce that implosion was probably going on. Especially if you were able to see under the ballistic casing itself, with all of those conspicuously-placed wires.

In recent years we have become rather accustomed to seeing pictures of retired weapons systems and their physics packages. Most of them are quite boring, a variation on a few themes. You have the long-barrels that look like gun-type designs. You have the spheres or spheres-with-flat ends that look like improved implosion weapons. And you then have the bullet-shaped sphere-attached-to-a-cylinder that seems indicative of the Teller-Ulam design for thermonuclear weapons.

Silhouettes of compact thermonuclear warheads. Are the round ends fission components, or spherical fusion components? Things the nuke-nerds ponder.

There are a few strange things in this category, that suggest other designs. (And, of course, we don’t have to rely on just shapes here — we have other documentation that tells us about how these might work.) There is a whole class of tactical fission weapons that seem shaped like narrow cylinders, but aren’t gun-type weapons. These are assumed to be some form of “linear implosion,” which somewhat bridges the gap between implosion and gun-type designs.

All of this came to mind recently for two reasons. One was the North Korean photos that went around a few weeks ago of Kim Jong-un and what appears to be some kind of component to a ballistic case for a miniaturized nuclear warhead. I don’t think the photos tell us very much, even if we assume they are not completely faked (and with North Korea, you never know). If the weapon casing is legit, it looks like a fairly compact implosion weapon without a secondary stage (this doesn’t mean it can’t have some thermonuclear component, but it puts limits on how energetic it can probably be). Which is kind of interesting in and of itself, especially since it’s not every day that you get to see even putative physics packages of new nuclear nations.

Stockpile milestones chart from Pantex's website. Lots of interesting little shapes.

Stockpile milestones chart from Pantex’s website. Lots of interesting little shapes.

The other reason it came to mind is a chart I ran across on Pantex’s website. Pantex was more or less a nuclear-weapons assembly factory during the Cold War, and is now a disassembly factory. The chart is a variation on one that has been used within the weapons labs for a few years now, my friend and fellow-nuclear-wonk Stephen Schwartz pointed out on Twitter, and shows the basic outlines of various nuclear weapons systems through the years. (Here is a more up-to-date one from the a 2015 NNSA presentation, but the image has more compression and is thus a bit harder to see.)

For gravity bombs, they tend to show the shape of the ballistic cases. For missile warheads, and more exotic weapons (like the “Special Atomic Demolition Munitions,” basically nuclear land mines — is the “Special” designation really necessary?), they often show the physics package. And some of these physics packages are pretty weird-looking.

Some of the weirder and more suggestive shapes in the chart. The W30 is a nuclear land mine; the W52 is a compact thermonuclear warhead; the W54 is the warhead for the Davy Crockett system, and the W66 is low-yield thermonuclear weapon used on the Sprint missile system.

A few that jump out as especially odd:

  • PowerPoint Presentation

    Is the fill error meaningful, or just a mistake? Can one read too much into a few blurred pixels?

    In the Pantex version (but not the others), the W59 is particular in that it has an incorrectly-filled circle at the bottom of it. I wonder if this is an artifact of the vectorization process that went into making these graphics, and a little more indication of the positioning of things than was intended.

  • The W52 has a strange appearance. It’s not clear to me what’s going on there.
  • The silhouette of the W30 is a curious one (“worst Tetris piece ever” quipped someone on Twitter), though it is of an “Atomic Demolition Munition” and likely just shows some of the peripheral equipment to the warhead.
  • The extreme distance between the spherical end (primary?) and the cylindrical end (secondary?) of the W-50 is pretty interesting.
  • The W66 warhead is really strange — a sphere with two cylinders coming out of it. Could it be a “double-gun,” a gun-type weapon that decreases the distance necessary to travel by launching two projectiles at once? Probably not, given that it was supposed to have been thermonuclear, but it was an unusual warhead (very low-yield thermonuclear) so who knows what the geometry is.

There are also a number of warheads whose physics packages have never been shown, so far as I know. The W76, W87, and W88, for example, are primarily shown as re-entry vehicles (the “dunce caps of the nuclear age” as I seem to recall reading somewhere). The W76 has two interesting representations floating around, one that gives no real feedback on the size/shape of the physics package but gives an indication of its top and bottom extremities relative to other hardware in the warhead, another that portrays a very thin physics package that I doubt is actually representational (because if they had a lot of extra space, I think they’d have used it).1

Some of the more simple shapes — triangles, rectangles, and squares, oh my!

Some of the more simple shapes — triangles, rectangles, and squares, oh my!

What I find interesting about these secret shapes is that on the one hand, it’s somewhat easy to understand, I suppose, the reluctance to declassify them. What’s the overriding public interest for knowing what shape a warhead is? It’s a hard argument to make. It isn’t going to change how to vote or how we fund weapons or anything else. And one can see the reasons for keeping them classified — the shapes can be revealing, and these warheads likely use many little tricks that allow them to put that much bang into so compact a package.

On the other hand, there is something to the idea, I think, that it’s hard to take something seriously if you can’t see it. Does keeping even the shape of the bomb out of public domain impact participatory democracy in ever so small a way? Does it make people less likely to treat these weapons as real objects in the world, instead of as metaphors for the end of the world? Well, I don’t know. It does make these warheads seem a bit more out of reach than the others. Is that a compelling reason to declassify their shapes? Probably not.

As someone on the “wrong side” of the security fence, I do feel compelled to search for these unknown shapes — a defiant compulsion to see what I am not supposed to see, perhaps, in an act of petty rebellion. I suspect they look pretty boring — how different in appearance from, say, the W80 can they be? — but the act of denial makes them inherently interesting.

Notes
  1. One amusing thing is that several sites seem to have posted pictures of the arming, fuzing, and firing systems of these warheads under the confusion that these were the warheads. They are clearly not — they are not only too small in their proportions, but they match up exactly to declassified photos of the AF&F systems (they are fuzes/radars, not physics packages). []