The Manhattan Project

by Cynthia C. Kelly

  Holes in the Security Fence

  The threat of espionage led to mail censorship, restricted communications and movements, armed guards, and undercover agents to watch suspicious Manhattan Project employees. Given the breaches in security, Joseph Albright and Marcia Kunstel speculate on what more should have been done to prevent atomic espionage.

  From Bombshell

  BY JOSEPH ALBRIGHT AND MARCIA KUNSTEL

  To guard fully against espionage would have meant clamping a security vise over the entire country. There were too many potential leaks in a program as geographically scattered as the Manhattan Project. As it was, security precautions were extraordinary for a country as open and unrestricted as the United States boasted of being. In the Soviet Union body searches might have been an accepted standard of security for civilian scientists and their families. In America it was not.

  Yet some things could have been done differently, especially given Groves’ worries about Soviet penetration—and the signs that it was actually happening. The most effective step would have been stronger and more public retribution against those found passing technical secrets. Joseph Weinberg, for example, was quietly drafted and dispatched to Alaska. The same thing happened in April 1944, after an FBI surveillance team in Chicago watched physicist Clarence Hiskey of the Metallurgical Laboratory meet with Arthur Alexandrovich Adams, a known Soviet spy. Hiskey was drafted and spent the rest of the war at a base near the Arctic Circle at Mineral Wells, Alaska. Weinberg and Hiskey had their security clearances revoked and were forbidden to work on nuclear projects, but news about their ruined careers was not circulated to other scientists. Even the case of Rotblat was entirely silenced. Even now the question lingers: Would Ted Hall have risked the trip to Amtorg [espionage] had he known about the travails of Weinberg and Hiskey?

  During the war the Manhattan Project’s unit of the Army Counter Intelligence Corps handled 100 cases of “probable” wartime espionage and 200 cases of possible sabotage. Not one resulted in a prosecution for a major crime. Had there been any obvious effect of the security precautions—had anybody been caught and publicly punished—Manhattan Project personnel might have better understood both the threat and the need for security. The military did not even conduct effective background checks before passing out top-secret clearances. All three known spies at Los Alamos had been members of the Communist Party or offshoots of it, yet the CIC wasn’t aware of any of their connections.

  One of the most vexing breaches of security in Groves’ view was Oppenheimer’s refusal to compartmentalize work. Groves had wanted to limit the exchange of information within Los Alamos so each scientist and technician would know only what was absolutely necessary to carry out his or her own small bit of research and experimentation. Oppenheimer refused, arguing that he needed an exchange of ideas if he were to build this new weapon quickly. He held weekly colloquia in which the leading scientists talked about their work, because he was convinced it was good for morale when people knew how their job fit into the overall picture. It worked. Oppenheimer produced a bomb in a remarkably short time. But Groves also was right: The lack of compartmentalization made life much easier for the spies of Los Alamos.

  A Calming Role for the Counterintelligence Corps

  Thomas O. Jones graduated from Harvard in 1941, volunteered for the Army, and was soon swept into the Manhattan Project. As part of Groves’s Counterintelligence Corps, he became head of counterintelligence at Los Alamos in April 1945. His predecessor, Captain Peer de Silva, had recently suggested that Groves remove Oppenheimer at a very critical time, accusing him of espionage. After investigating these allegations, Groves replaced de Silva and directed Jones to calm things down at Los Alamos. In this excerpt, Jones recounts a particularly memorable day on the job.

  From AHF Oral Histories

  INTERVIEW WITH THOMAS O. JONES

  I was in my office when the phone rang. Washington was calling, which happened steadily throughout the day. But this was to report that President Roosevelt had just died in Warm Springs.

  The first thing I had to do was get to Oppenheimer. His office was just across the main street of the technical area in a long wooden GI Army building parallel to mine. An arched wooden walkway connected the two buildings on the second floor and I hastily began to walk across the footbridge. As I came up over the bend, I saw a figure heading towards me.

  I knew at once that Oppenheimer was heading for my office just as I was a bit ahead of him heading for him. We met knowing what the subject was going to be and he said “Is it true?” and I said, “Yes, Oppie.” It confirmed what he probably expected to hear and he wanted to talk about it for a few minutes. I could sense at once that he had strong feelings about Roosevelt.

  Oppie was ruminating about a previous encounter with Roosevelt at which he had been very struck by the man’s personality. He had been very impressed, not just with the mind, but with the cordiality and thoughtfulness he had found in Roosevelt on that occasion. It had been a deep experience for him, just as it was a deep experience for me to behold this reaction to the news on Oppenheimer’s part.

  I could not conceive of someone who had come away from the meeting with Roosevelt feeling as he did about him as someone who would betray his country. That brief exchange concerning Roosevelt was something out of the ordinary and decided how I felt about Oppie. We departed as casual friends; it was a rather deep casual friendship.

  When he left Los Alamos later, he sent me a large photograph of himself on which he had written “in memory of common woes.”

  The Alsos Mission: Scientists as Sleuths

  In this excerpt, Robert S. Norris discusses the concerns of General Groves and other officials regarding the German atomic bomb program. Groves formed “Alsos,” a scientific intelligence organization, to uncover information about German developments in Europe. Samuel A. Goudsmit, a Dutch-born physicist teaching at the University of Michigan, was chosen to be the scientific director and Lieutenant Colonel Boris T. Pash, previously head of the counterintelligence branch of the Western Defense Command and the Fourth Army, was selected as the military leader.

  From Racing for the Bomb

  BY ROBERT S. NORRIS

  For Groves fear and suspicion filled the void of his ignorance about whether Germany was working on an atomic bomb. Groves had an early appreciation of how important the bomb was going to be. If they possessed it, they could dictate their terms to the rest of the world. This obsession drove Groves to race faster to build his bomb, and to stop the Germans by any means necessary from building theirs.

  In the process Groves introduced some novel features into foreign intelligence operations and practices, supplementing his contributions in the domestic area. The most distinctive was the Alsos mission, a successful venture in “scientific intelligence.” During the Cold War that followed, the role of science and scientists in the intelligence field would be greatly enhanced. Highly sophisticated means would be used to gather and analyze information.

  Early in 1943 John Lansdale conceived of forming an intelligence unit comprised of combat troops and scientists that would apprehend European scientists thought to be working in nuclear physics, and seize their records. In later recounting this Lansdale noted that others had similar ideas, but he was the one who was successful in securing General Staff approval.…

  The name given to the special unit was Alsos, Greek (αλσoσ) for “a sacred grove” (in this case the reference is to a small wood or forested area, and not to “groves” or “Groves”). General Groves was not happy with the choice, because it might betray a secret, but changing it might draw even more attention, so Alsos it was.

  Oppenheimer and the scientists were asked to help pinpoint things that the agents should look for. Evidence of raw materials, uranium, pure graphite, heavy water, and beryllium would indicate suspicious activity, as would certain-sized plants. “If the Germans are operating a production pile they will be operating it where water is plentiful and where the flow
from the plant passes either through open country or through country inhabited by an ‘inferior race’ whom they do not mind killing off,” he told Maj. Robert F. Furman, Groves’s chief aide on foreign intelligence matters. If a few cubic centimeters of water could be collected from a river downstream of a suspected plant, the sample could be tested for radioactivity.

  The British supplied the Manhattan Engineer District with intelligence and their assessments of it. While Groves was generally pleased with the cooperative exchanges of intelligence with the British, he remained largely unconvinced about their conclusions. The British view of the German bomb was that there was no large-scale program under way. Groves, on the other hand, adopted a worst-case analysis, assuming that until it was confirmed otherwise, Germany was working on a bomb at full capacity. He wrote,

  Unless and until we had positive knowledge to the contrary, we had to assume that the most competent German scientists and engineers were working on an atomic program with the full support of their government and with the full capacity of German industry at their disposal. Any other assumption would have been unsound and dangerous.

  [Horace] Calvert’s group concentrated on collecting information about German atomic activities, specifically on individual nuclear scientists, on the location of laboratories and industrial facilities, and on the mining of fissionable materials. Through canvassing German physics journals and questioning refugees Calvert’s unit learned the whereabouts of the most important German scientists, and through periodical aerial surveillance of the mines at Joachimstal, Czechoslovakia, it monitored the mining of uranium ore. All of this was to be enormously helpful to the Alsos team, which was preparing to follow the invading Allied armies onto the continent in June 1944.

  From France to the Black Forest: Seeking Atomic Scientists

  In this excerpt, Richard Rhodes tells the story of Lieutenant Colonel Boris Pash’s pursuit of German scientists during the Alsos mission and discovery of an atomic pile at Haigerloch, Germany.

  From The Making of the Atomic Bomb

  BY RICHARD RHODES

  Pash set up a base in London in 1944 as the Allied armies pushed through France after the Normandy invasion. He then crossed the Channel with a squad of Alsos enlisted men and wheeled toward Paris by jeep.… The American force stopped outside Paris—Charles de Gaulle had persuaded Franklin Roosevelt to allow the Free French to enter the city first—but Pash decided to improvise: “Colonel Pash and party then proceeded to cut across-country to Highway 20 and joined second elements of a French armored division. The ALSOS Mission then entered the City of Paris 0855 hrs., 25 August 1944. The party proceeded to within the city in the rear of the first five French vehicles to enter, being the first American unit to enter Paris.” The first five French vehicles were tanks. In his unarmored jeep Pash drew repeated sniper fire. He dodged among the back streets of Paris and by the end of the day had achieved his goal, the Radium Institute on the Rue Pierre Curie. There he settled in for an evening to drink celebratory champagne with Frédéric Joliot.

  Joliot knew less about German uranium research than anyone had expected. Pash moved his base to liberated Paris and began following up promising leads. One of the most significant pointed to Strasbourg, the old city on the Rhine in Alsace-Lorraine, which Allied forces began occupying in mid-November. Pash found a German physics laboratory installed there in a building on the grounds of Strasbourg Hospital. His scientific counterpart on the Alsos team was Samuel A. Goudsmit, a Dutch theoretical physicist… who had previously worked at the MIT Radiation Laboratory. Goudsmit followed Pash to Strasbourg, began laboriously examining documents and hit the jackpot. He recalls the experience in a postwar memoir:

  It is true that no precise information was given in these documents, but there was far more than enough to get a view of the whole German uranium project. We studied the papers by candlelight for two days and nights until our eyes began to hurt.… The conclusions were unmistakable. The evidence at hand proved definitely that Germany had no atom bomb and was not likely to have one in any reasonable form.

  But paper evidence was not good enough for Groves; as far as he was concerned, he could close the books on the German program only when he had accounted for all the Union Minière uranium ore the Germans had confiscated when they invaded Belgium in 1940, some 1,200 tons in all, the only source of untraced bomb material available to them during the war with the mines and Joachimsthal under surveillance and the Belgian Congo cut off.

  Pash had already liberated part of that supply, some 31 tons, from a French arsenal in Toulouse where it had been diverted and secretly stored. Moving into Germany with the Allied armies after they crossed the Rhine late in March he acquired a larger force of men, two armored cars mounted with .50-caliber machine guns and four machine-gun-mounted jeeps and began tracking the German atomic scientists themselves. “Washington wanted absolute proof,” Pash remembers, “that no atomic activity of which it did not know was being carried on by the Nazis. It also wanted to be sure that no prominent German scientist would evade capture or fall into the hands of the Soviet Union.”

  Alsos documents placed Werner Heisenberg, Otto Hahn, Carl von Weizsäcker, Max von Laue and the others in their organization in the Black Forest region of southwestern Germany in the resort town of Haigerloch. By late April the German front had broken and the French were moving ahead. Pash and his forces, which now included a battalion of combat engineers, got word in the middle of the night and raced around Stuttgart in their jeeps and trucks and armored cars to beat the French to Haigerloch. They drew German fire along the way and returned it. In the meantime Lansdale in London reassembled his British-American team and flew over to follow Pash in. The story is properly Pash’s:

  Haigerloch is a small, picturesque town straddling the Eyach River. As we approached it, pillowcases, sheets, towels and other white articles attached to flagpoles, broomsticks and window shutters flew the message of surrender.

  … While our engineer friends were busy consolidating the first Alsos-directed seizure of an enemy town, [Pash’s men] led teams in a rapid operation to locate Nazi research facilities. They soon found an ingenious set-up that gave almost complete protection from aerial observation and bombardment—a church atop a cliff.

  Hurrying to the scene, I saw a box-like concrete entrance to a cave in the side of an 80-foot cliff towering above the lower level of the town. The heavy steel door was padlocked. A paper stuck on the door indicated the manager’s identity.

  … When the manager was brought to me, he tried to convince me that he was only an accountant. When he hesitated at my command to unlock the door, I said “Beatson, shoot the lock off. If he gets in the way, shoot him.”

  The manager opened the door.

  … In the main chamber was a concrete pit about ten feet in diameter. Within the pit hung a heavy metal shield covering the top of a thick metal cylinder. The latter contained a pot-shaped vessel, also of heavy metal, about four feet below the floor level. Atop the vessel was a metal frame.… [A] German prisoner… confirmed the fact that we had captured the Nazi uranium “machine” as the Germans called it—actually an atomic pile.

  Pash left Goudsmit and his several colleagues behind at Haigerloch on April 23 and rushed to nearby Hechingen. There he found the German scientists, all except Otto Hahn, whom he picked up in Tailfingen two days later, and Werner Heisenberg, whom he located with his family at a lake cottage in Bavaria.

  The pile at Haigerloch had served for the KWI’s [Kaiser Wilhem Institute’s] final round of neutron-multiplication studies. One and a half tons of carefully husbanded Norsk-Hydro heavy water moderated it; its fuel consisted of 664 cubes of metallic uranium attached to 78 chains that hung down into the water from the metal “shield” Pash describes. With this elegant arrangement and a central neutron source the KWI team in March had achieved nearly seven-fold neutron multiplication; Heisenberg had calculated at the time that a 50 percent increase in the size of the reactor would produce a susta
ined chain reaction.

  “The fact that the German atom bomb was not an immediate threat,” Boris Pash writes with justifiable pride, “was probably the most significant single piece of military intelligence developed throughout the war. Alone, that information was enough to justify Alsos.” But Alsos managed more: it prevented the Soviet Union from capturing the leading German atomic scientists and acquiring a significant volume of high-quality uranium ore. The Belgian ore confiscated at Toulouse was already being processed through the Oak Ridge calutrons for Little Boy.

  “I have been expecting you”

  Colonel John Lansdale Jr. was in charge of security for General Groves and was instrumental in conceiving and executing the Alsos mission. In his memoirs, Lansdale recalls his Alsos activities in Europe, including a memorable encounter with the physicist Otto Hahn. The Alsos mission revealed that the German bomb project had not gotten very far.

  From “Military Service”

  BY COLONEL JOHN LANSDALE JR.

  On the 25th of April we went on to Tailfingen where my notes show that we found Otto Hahn and an almost complete set of the German reports on atomic energy.… He was sitting at a desk in his office. He had a suitcase beside him and when I walked in, he said in English, “I have been expecting you,” and came with me without further delay.

  On the 26th of April, Eric Welsh, M. W. Perrin, and I interrogated German scientists Max Von Laue, Carl von Weizsacker, Karl Wirtz, and Otto Hahn. After much interrogation they agreed to show us the hiding places of their heavy water and uranium. On that day we got the heavy water, stored in metal barrels, out of the cellar of an old mill about five kilometers from Haigerloch. The metallic uranium had been buried in a field near Haigerloch and the field then plowed.