Part Two - The Plutonium Bomb


Chapter Six - Timing

"Lt. (JG) H E Morgan, Lt. (JG) F M Abbott, Ens F L Granger with Dr. Schlicke POW in custody leaving Anacostia noon Friday via plane.  This party expert in bomb disposal and proximity fuses and being sent to assist in securing certain infra red proximity fuses important BUORD [Navy Bureau of Ordnance - author's note] and in cargo U-234.  Fuses when secured to be returned Washington custody above party."ccxxx
            Dispatch from Chief of Naval
            Operations to Portsmouth Naval Yard, 25 May, 1945

"After Dr. Schlicke completes his lecture he will be available for questions that people ask.  But we will kindly ask you not to ask any questions during the lecture and after the lecture Mr. Alvarez will sit at the table and the person who wishes to ask a question is asked to come forward so that we can get in the microphone and keep a record of all the questions and answers."ccxxxi
   From the transcript of an introduction to a lecture given
   by Dr. Heinz Schlicke to the Navy Department.
   "Mr. Alvarez" appears to be Dr. Schlicke's handler.
   Manhattan Project physicist Luis Alvarez was credited
   with at the last minute solving the plutonium bomb's fuse problems

  Uranium does not appear to be the only component aboard U-234 capable of being used to make an atomic bomb.  There were the steel drums and wooden barrels full of fluids, noted in Chapter One, which Manhattan Project personnel tested, apparently to see if the materials had been, or could be, part of a plutonium breeder reactor.ccxxxii  And there were tons of lead, possibly for radiation protection; mercury, possibly for very fast mercury switches; and infra-red proximity fuses.

 The infra-red fuses were discovered within five days of U-234's landing at Portsmouth, apparently as the result of Dr. Heinz Schlicke's interrogation.  A memorandum written by Jack H. Alberti dated 24 May 1945ccxxxiii stated,

"Dr. Schlicke knows about the infra-red proximity fuses which are contained in some of these packages....Dr. Schlicke knows how to handle them and is willing to do so."

  According to the following transmission, at noon the very next day, Schlicke was placed on an airplane with a three-man escort and flown back to Portsmouth, for the sole purpose of retrieving the proximity fuses.

"Lt. (JG) H E Morgan, Lt. (JG) F M Abbott, Ens F L Granger with Dr. Schlicke POW in custody leaving Anacostia noon Friday via plane.  This party expert in bomb disposal and proximity fuses and being sent to assist in securing certain infra red proximity fuses important BUORD [Navy Bureau of Ordnance - author's note] and in cargo U-234.  Fuses when secured to be returned Washington custody above party."ccxxxiv

  The dossier on the technology portfolio Schlicke took to Japan was extensive.  He was either referenced by other prisoners of U-234, listed in documents onboard U-234, or admitted to being knowledgeable in or responsible for: very high technology radar and radio systems,ccxxxv guided missile development, and V2 rockets.ccxxxvi  While still in Germany, he also had met with a long list of scientists.  He noted in his interrogation that the intent of many of these meetings was for him to receive the transfer of their technologies and to later disseminate them in Japan, and to serve as the listed scientists' liaison and advisor with Japan.ccxxxvii

  Among the scientists with whom he had coordinated, which he listed for American interrogators, were Professor Dr. Esau and Professor Gerlach,ccxxxviii both of whom, at one time or another, were important members of Germany's atomic research programs.ccxxxix Dr. Esau had served as head of the Kaiser Wilhelm Institute and was a member of the Reich Research Council.  Much of the technology accompanying Schlicke to his destination was the product of this group of 54, obviously very high-level, scientists.

  That Schlicke was personally and almost immediately flown back to U-234 specifically to retrieve the infra-red fuses, from among all the technology for which he was responsible, seems very revealing.  It suggests that the infra-red fuses were of immediate interest to the United States, not just as the booty of war, as were all the other technologies on the boat, but expediting retrieval of the fuses seems to have been driven by a need to have them immediately available for some purpose.

  That purpose may have been hinted at a short time later.  On 19 July 1945, Dr. Schlicke presented a lecture to members of the Navy Department.  A portion of the transcribed introduction of Dr. Schlicke bears an innocuous clue to the possible purpose of the infra-red fuses. "After Dr. Schlicke completes his lecture he will be available for questions that people ask.  But we will kindly ask you not to ask any questions during the lecture and after the lecture Mr. Alvarez [italics added] will sit at the table and the person who wishes to ask a question is asked to come forward so that we can get in the microphone and keep a record of all the questions and answers."ccxl

  The presence of a "Mr. Alvarez" as Dr. Schlicke's apparent host or "handler" may be a singular indicator regarding the importance of the infra-red fuses.  The reference to Mr. Alvarez was not the first to be made from among U234's passengers and crew.  Three weeks earlier, General Kessler had written a letter regarding missing personal items in which he identified a "Commander Alvarez" as having seen some of these items.ccxli  The identification that Alvarez held the rank of commander appears on the face to indicate he was a Navy Officer; no other United States services maintain a rank of Commander except the Coast Guard, which is very unlikely to have been involved with the U-234 intelligence operation.

  U-234's skipper, Captain Lieutenant Johann Heinrich Fehler, also identified Alvarez in a letter written decades after the war, but he identified Alvarez as a Lieutenant Commander.ccxlii  The distinction between whether Alvarez was a full Commander or a Lieutenant Commander would be minimal, except that it may be a moot point altogether. Alvarez may not have been a Navy officer at all.  In parenthesis in his letter, Fehler, following his identification of Alvarez, noted that Alvarez is "probably not his real name."

  Fehler seems to have sensed that there was something disingenuous about Alvarez but assumed that it was his name, not his rank, that was dubious.  The name, in fact, may have been a counterfeit.  There is no listing of any officer surnamed Alvarez in either the Register of Commissioned and Warrant Officers of the United States Navy and Marine Corps for either July 1, 1943 or it publication two years later on July 1, 1945.

  But there is another explanation.  The name Alvarez may have been real, but the rank of commander was a fraud, and that was the ill-defined deception Fehler was sensing.

  At the time U-234 was escorted into Portsmouth Harbor, the Manhattan Project was near desperation.  Because Groves appears to have decided to use some of the already enriched uranium to fuel the plutonium reactors at Hanford, he was short of enriched uranium for the uranium bomb. The Manhattan Project scientists had not figured out a way to efficiently trigger the plutonium bomb.  And the mid-August deadline for any kind of bomb was fast approaching.

  The plutonium bomb consisted of a hollow sphere of plutonium the size of a small orange.  The key requirement to make the bomb explode - besides the creation of the requisite amount of plutonium - was to compress the plutonium sphere so it would reach critical mass.  To achieve this compression, 32 redundant detonators - 64 in all - needed to be fired within 1/3,000th of a second, or the bomb would fail.

  The challenge was daunting.  For a year-and-a-half, the Los Alamos scientists tried to develop a simultaneously firing detonation system. Just a month before U-234 landed, there was "more than a bare possibility that the detonators will be unsatisfactory"ccxliii wrote Norris Bradbury, who headed the team responsible for triggering the explosion.  Indeed, into late June and early July, just two weeks before the first atomic bomb test at Alamogordo, New Mexico, the detonator timing problem was still not resolved.ccxliv

  The experts at Los Alamos had been working on the timing problem since the fall of 1943,ccxlv but had failed to solve it when, in October 1944, Robert Oppenheimer created a committee to tackle the detonator problem. The first name on the three-man team was Luis Alvarez.ccxlvi

  Alvarez had begun his wartime work in the Radiation Lab at MIT, then worked on Ground Controlled Approach Radar, which allowed controllers to "talk down" a pilot whose vision was impaired.ccxlvii  He then worked on Phased-array Radar, which allows a radar system to track an object electro-magnetically rather than steering the system by manual means. After the war, Alvarez went on to win the Nobel Prize for Physics in 1968 for his work on aeronautical navigation systems.  And he, with his son Walter and geologist Frank Asaro, were the first to forward the theory that Earth was struck by a meteorite that caused the extinction of the dinosaurs.  They based their theory on findings of high levels of iridium in concentrated locations on earth.  At first scorned, the theory has become widely accepted.

  Luis Alvarez also became one of the great heroes of the atomic bomb story when he solved the plutonium bomb detonator timing problem in the last days before the Trinity Test.ccxlviii  In his own account of his work in the Manhattan Project, he wrote simply that he "cleaned up some loose ends in detonator design."ccxlix  The understatement and lack of detail may be telling - especially if it was meant to hide how he "cleaned up" those details.

  Of all the Manhattan Project personnel whose name one would expect to see connected to Heinz Schlicke's and U-234's infra-red proximity fuses, if there was a connection, Luiz Alvarez's name would be at the top of that list.  The two scientists' backgrounds were strikingly similar; both men were leaders in the field of high frequency light waves.  When it came to science, they spoke the same language.  If the Manhattan Project wanted somebody to debrief Schlicke or anyone aboard U-234 about atomic bomb development, Alvarez would have been the logical choice.

  He was one of the very few people who had a broad view and understanding of all the aspects of the program.  By late spring 1945, when U-234 arrived on American shores with just two months left until the Trinity Test - the first test of an atomic bomb - the detonator problem was still unsolved and its resolution was now paramount to the success of the entire program.  Alvarez, as the key man assigned to the problem, was in desperate need of a fusing system that could fire multiple detonators simultaneously.  Schlicke had fuses that worked on the principles that govern light - presumably they worked at the speed of light.

  In fact, among the documents Schlicke was accompanying to Japan was a report on "the investigation of the usability of ultraviolet (invisible) light for transmitting messages or commands and particularly for the remote ignition of warhead fuses."ccl  The report had been prepared based on research done from 1939 through 1941 by Hans Klumb and Bernard Koch.

  In suggesting that "the ultraviolet method permits the transmission of much more concentrated energy compared with the infra-red method," the inference is made that infrared was also usable for similar purposes, though lower concentrations of energy made it problematic.  Ultraviolet light, on the other hand, according to the same report, appears to have presented its own challenges to the task because it had a "stronger absorption rate."
  Certainly nothing is proven regarding Schlicke's fuses from this independent report, but the document appears to show that the technology could be used for controlling the type of warhead detonation Luis Alvarez required for the plutonium bomb.  The fact that somebody named "Alvarez" was in contact with Schlicke and apparently involved in his and others of U-234's passengers' interrogations, seems to be more than a coincidence.

  And the fact that "Commander Alvarez" was not actually perceived by Captain Fehler as being who he claimed to be, provides an interesting, if subjective, observation regarding Commander Alvarez. Fehler mentioned in his letter that Alvarez, who was his interrogating officer, "has always been correct, even when sometimes trying to press some knowledge out of me and to threaten me in a rather primitive way." (sic)  The statement that Alvarez was "always being correct, even when threatening in a primitive way" seems on the face of it to be incongruent.  But if Alvarez, whoever he was, was not used to interrogating people - as Luis Alvarez surely would not have been - if he was doing his best without the interrogation skills required, would that not qualify as a primitive interrogation, too?  Especially if the language in which you were describing the event - English - is your second language, as it was Fehler's?

  But what about the identification of Alvarez as a Commander in the Navy? General Leslie Groves, who was in charge of the Manhattan Project, supplied military identities - uniforms, ranks and papers - to scientists Robert Furman and James Nolan, so they could escort the enriched uranium bomb cores to Tinian on board the USS Indianapolis without raising suspicion.ccli  Harlow Russ also recounted in his writings how a Major Vanna, an intelligence officer responsible for the technical crew of the plutonium bomb, always carried with him a cigar box full of rank insignias from every military service.

  He passed one to each of the team of civilian technicians to wear on their uniform-looking coveralls, so they would not be hindered by military personnel as they concluded their secret project.cclii  General Groves, himself, corroborated this story in his book Now It Can Be Told, when he recounted how each civilian in the 37-man team of the First Technical Service was required to wear a uniform with a simulated Army rank.ccliii That Schlicke was returned to U-234 specifically to pick up the proximity fuses further seems to substantiate that Commander Alvarez, Schlicke's handler, and Luis Alvarez, who solved the plutonium bomb fusing problem, are one and the same. This suggestion is also strongly supported by two factors.

  First, according to Harlow Russ, who wrote in his book Project Alberta about his work on the team that assembled the plutonium bomb, two significant changes were made to the bomb design at the last minute.  One was the development and inclusion in the plutonium bomb of "detonator chimneys"ccliv that were developed so late in the process that they were not included in the first four shipments of equipment to Tinian, the Pacific airfield from which the bombs were dropped on Japan.  The second design addition was a series of small-diameter stainless steel tubes that "vented" radiation from the plutonium core, according to Russ's explanation, to allow the technicians to monitor activity at the core.cclv

  Russ makes a point of stating both additions were new and just in time for the Trinity Test. These modifications suggest that very late before the plutonium bomb's use, passages were being built into the bomb that, presumably, would allow the free flow of radiation, or light waves, throughout the device.  Theoretically, with these passages in place, once any one of the 64 detonators was ignited, the system allowed emitted infrared waves to travel at the speed of light through the "detonator chimneys" to the other detonators/fuses and simultaneous ignite all the fuses at the speed of light.

  As a back-up plan, once any one of the firing detonators compressed the plutonium core at the center enough to achieve even a partial chain reaction, the radiation from that event would be emitted out to the detonators, again at the speed of light, and, again, simultaneously fire all of the detonators. Obviously, this is speculation based on various, often apparently unrelated evidence. But given the timing of the developments, from Alvarez's arrival on the U-234 scene, to Schlicke's special trip to retrieve the fuses, to Alvarez's solving the timing problem so late in the process, and Russ receiving last-minute design changes apparently initiated to provide paths for the free movement of light waves within the bomb, such a scenario certainly seems viable.

  In an effort to substantiate or eliminate this theory, I tried to call Harlow Russ on the telephone at his home in Los Alamos to ask him about the detonator chimneys, venting tubes, and if, in general, there were any significant changes to the actual detonators themselves. Unfortunately my call came too late; I was informed Mr. Russ had died in the few months between when I received from him his book and when I had developed the above scenario.
  The second factor suggesting the detonators used to fire the plutonium bomb came from Dr. Schlicke is the striking success of the Trinity Test of the plutonium bomb. Trinity was "successful beyond the most optimistic expectations of anyone," wrote General Groves.cclvi  "Nearly everyone was surprised,"cclvii Robert Serber recorded.  In his quintessential tome on the subject, The Making of the Atomic Bomb, Richard Rhodes wrote that Trinity was four times its expected yield.cclviii

  What could have caused such a remarkable miscalculation by the experts? Those who knew the problems the system was experiencing in firing all of the detonators at once by mechanical means, but were unaware that the proximity fuses were being utilized to make detonation occur at the speed of light, certainly would not have expected the profoundly superior results.

  Thinking the detonation was still limited by hard-cable restrictions and physical switches, and based on tests of these systems, the scientists were expecting a much less dramatic event. Instead, they were surprised by the power and efficiency of the explosion.  That so many who knew what the outcome of the detonation should have been were so surprised by how efficient it actually was, tends to indicate that Schlicke's infra-red proximity fuses were used to compress the plutonium core at the speed of light.



Back to Contents