The Winter Fortress

by Neal Bascomb

  Over the next several days, Brun worked with Harteck to formulate the way forward at Vemork. The plant revisions needed to be implemented immediately, no matter the cost. With the improvements, Harteck figured they could produce at least eight kilograms a day. Further, Brun was told, Norsk Hydro needed to consider constructing heavy water plants at two other hydroelectric power stations: Såheim (in Rjukan proper) and in Notodden. They were smaller power plants, with more limited electrolysis facilities, but together they could add another six kilograms a day, bringing total production to five thousand kilograms a year, possibly more.

  Some of the scientists Brun met in Berlin sympathized with Norway’s plight and spoke quietly of their disgust with Hitler. They warned Brun to be careful of what he said to whom, particularly to the more ardent Nazis such as Diebner. Even so, none of them would reveal what they needed the heavy water for, although they assured him it was not for the war. It was a disturbing trip. Too often Brun heard the phrase “Heil Hitler.” Signs on the trams warned of enemy ears. There were only spare amounts of food at the Kaiser Wilhelm Institute’s canteen, and the offices were barely heated. One day, Brun passed several young Jewish girls on a corner who had yellow stars sewn onto their shirts.

  On returning home, Brun had no choice but to begin instituting the expansion. Workers doubled the number of high-concentration cells to eighteen. The nine-stage cascade, already huge, grew to include over forty-three thousand cells. In addition, Brun started a pilot test of the catalytic exchange process, and plans were developed for Såheim and Notodden.

  In May, Terboven visited Vemork, then Harteck returned to refine his new exchange method before it was finally implemented. Production was up—from an average of 80 kilograms a month in December 1941 to 130 kilograms in June 1942—and still rising. Såheim and Notodden were soon to be operational as well.

  All this information and more Skinnarland and Brun, operating independently, sent in coded messages through a system of couriers to Oslo, then on to Sweden. Some were secreted inside toothpaste tubes. Others were taped to the backs of the messengers bringing them across the border. Then they were sent by plane to London, where they made their way to Chiltern Court.

  One report from Skinnarland detailed the meager security at the plant, stating that the Germans “depend too much on the surrounding natural defenses. The night guard is usually Georg Nyhus, a middle-aged, decent fellow. A neighbor. He should not be hurt. His only job is to check the permits of workers through his window, after they have been cleared by the two sentries on the bridge.”

  Another from Brun, labeled “High Concentration Plant for Enrichment of Glucose,” included an inventory of the plant down to the lead pipes, sand seals, rubber connections, and flanges of the high-concentration cells. Microphotographs of building blueprints, detailed drawings of equipment, and production figures followed. It was everything one might need to build a heavy water plant, or indeed to destroy the only one in existence.

  On June 4, 1942, Kurt Diebner watched a line of guests—some in fine suits, others in uniform—file into the lecture room at Harnack House, headquarters of the Kaiser Wilhelm Institute. In addition to scientists involved in atomic research, the attendees included General Emil Leeb, Admiral Karl Witzell, and Field Marshal Erhard Milch, respectively the armaments chiefs of the German army, navy, and air force. The hawk-eyed Albert Speer, the newly appointed minister for armaments and war production, had called them together to decide the future of the atomic program. Even though this had been launched on Diebner’s initiative, it was Heisenberg who took to the stage to present their findings, sidelining Diebner.

  In the first two years of the Uranium Club’s existence, they had made steady advances in atomic science. Thanks to the Nazis’ military successes, they had an easy channel to Vemork’s heavy water, a substance made all the more important by the final determination that it was both superior to graphite as a moderator (based on a mistaken calculation by one of its chief scientists, Walther Bothe) and easier to obtain in a highly purified form than the carbon product. They also had access to tons of Belgian uranium ore and a cyclotron in Paris commandeered from Frédéric Joliot-Curie to experiment with subatomic-particle collision.

  Over seventy scientists, distributed over a number of institutes, were pursuing basic but necessary research on everything from the energies of fission products, to several methods of U-235 isotope separation, to the construction of a uranium machine, to, finally, the likelihood of a new fissile material created from such a machine: element 94 (what the Americans were calling plutonium). They had broken ground on a new laboratory next to the Kaiser Wilhelm Institute of Physics (dubbed the Virus House to discourage unwelcome visitors). All looked bright for the future.

  Of all the developments, the most exciting related to the construction of a uranium machine. In Leipzig in September 1941, with assistance from Heisenberg, Professor Robert Döpel built a small spherical machine with two concentric layers of uranium oxide and heavy water, a beryllium neutron source at its core. They submerged the sphere in a vat of water and awaited the test results. The increase in neutrons was small, but it was there, evidence that the machine was successfully splitting U-235 atoms. With more layers of heavy water and higher-grade uranium, Heisenberg knew “in his bones” that they would have a self-sustaining pile. From that point forward, he said, there was “an open road ahead of us, leading to the atomic bomb.” Diebner agreed. In his mind, success was now a matter of shifting all their basic research into an industrial program.

  But two months later, with the Russians counterattacking on the Eastern Front and Hitler calling on Germany to focus on meeting the short-term demands of the war, Erich Schumann, Diebner’s supervisor and no fan of “atomic malarkey” from the start, called for another review of the research. On December 16, Schumann recommended to his generals that responsibility for the program be handed over to the Reich Research Council, the civilian-run, industry-centered body for basic and applied scientific research. A weapon, even if achievable, was still too far off, Schumann determined. The generals punted a decision to a second conference in February 1942. By then, one of the council’s lead scientists, Abraham Esau, was already being put forward as a potential new head of any overall group. A pioneer in wireless telegraphy, professor of physics, and a man of considerable influence in the Reich, Esau had been stripped of fission research by the army when Diebner was made head of the Uranium Club in 1939. Now he looked poised to have his revenge.

  For that second Army Ordnance conference, held on February 26, Diebner made his case in an exhaustive 131-page report. “In the present situation, preparations should be made for [harnessing] atomic energy . . . all the more in that this problem is also being worked on intensively in the enemy nations, especially in America.” With five tons of uranium metal and heavy water, and a self-sustaining machine, “a bomb of the greatest effectiveness” using between ten and one hundred kilograms of plutonium was in sight. Diebner offered a step-by-step plan to reach this goal. He simply needed the manpower, supplies, and capital to achieve it.

  The very same day, the Reich Research Council held its own meeting on atomic physics with Hahn, Heisenberg, and Esau as lead speakers. Attendees at the conference came away impressed at the technology’s future potential. Goebbels wrote in his diary, “Research in the field of demolishing atoms is so advanced that its results can perhaps be used for waging this war. Here tiny efforts result in such immense destructive effects that one looks forward with horror at the future course of this war.”

  But the army generals remained unconvinced. Diebner could not promise success with certainty. Unable to justify such expense and effort without the guarantee of a weapon within a year, the army forfeited control of the Uranium Club to the Reich Research Council. A further blow for Diebner came when Heisenberg was chosen to be the new director of the Kaiser Wilhelm Institute of Physics, and Diebner was forced to vacate his offices there.

  Four months after the sh
akeup, Diebner still believed there was a chance for an industrial-scale program. Speer, who had maneuvered the project within his sphere of influence, had called the June 1942 meeting at Harnack House to decide how much backing he should give it.

  Heisenberg took the stage to present the scientists’ findings. Tall, blue-eyed, with a sweep of straw-colored hair, he commanded the room in a way Diebner never could. He began by giving a theoretical overview of atomic science, then dove down into the specifics of isotope separation, uranium machines, and the production of plutonium. Then he hit his audience with the potential of the technical application of this science. With a uranium machine, they could “power ships, possibly even aircraft, with the greatest imaginable range.” With plutonium, they could produce explosives that “will be a million times more effective than all previous explosives.” One general, who had visions of dropping bombs on New York, wanted to know how big such bombs would be. Heisenberg cupped his hands and said, “About the size of a pineapple.”

  Heisenberg then shifted to downplaying expectations. They were still at the basic research phase, he said. More theory needed to be developed, more experiments performed. There were many obstacles standing in their way as well, including supplies of heavy water. One day, far in the future, a bomb might “turn the tide of war,” he concluded; but first they needed a working reactor, and that was a long way off.

  Speer then asked how much money their project needed. Heisenberg proposed a sum of 350,000 marks—in effect, nothing at all. There were other programs, namely V-1/V-2 flying bombs, whose scientists had demanded billions of marks and tens of thousands of workers in order to complete their projects and see them put to use in the war. Speer was flabbergasted, Diebner furious that Heisenberg would ask for such a trifling sum. If one was certain of a pineapple-sized bomb deciding the war, and if one was bent on producing it, much more would be needed to bring it to fruition.

  After the meeting, Speer steered his backing toward programs like flying bombs that he believed would most benefit Germany’s immediate war strategy. Basic research on harnessing atomic power would continue. The Reich Research Council would lead the project, and Army Ordnance would help fund it. Scientists would have ready access to supplies, and they would remain exempt from military service to do their work. But unless there was reason to reconsider, all this research was focused on future potential. There would be no massive project to see it made of any use in this war.

  Diebner was undeterred. He returned to his research at Army Ordnance’s Kummersdorf Testing Facility in Gottow, fifteen miles southwest of Berlin. With a host of young physicists he had recruited in the first days of the program, he quietly continued building his own uranium machine with a very different design from the ones that others had engineered. Hard and fast, he pressed on toward a bomb.

  Prime Minister Winston Churchill chewed on a cigar as he stared out at the Atlantic’s moonlit waters on June 17, 1942. Seated in the cockpit of a Boeing Clipper flying boat, he had many matters weighing on his thoughts as he flew toward the United States. The whole of continental Europe remained under Hitler’s heel, and though British and American bombers pummeled Germany night after night, only a cross-Channel invasion could liberate the Continent. But Churchill knew that Allied forces were far from ready for such an attack. He must convince the U.S. president, Franklin D. Roosevelt, to delay an invasion—one of the two key purposes for his twenty-eight-hour journey across the Atlantic. The other was to discuss atomic bombs.

  After a glass of champagne and a restless nap, Churchill fastened his seat belt for landing beside his trusted chief pilot, Rogers. The Clipper glided past the Washington Monument and landed on the Potomac. In the capital he met with General Marshall, and the next morning Churchill flew up to Hyde Park, New York, the site of Roosevelt’s family estate. The American president greeted him on the tarmac. Physically, the two men were a study in contrasts: the short, feisty British bulldog beside the tall, smooth American lion. But Churchill and Roosevelt were both intellectuals as well as cunning politicians, and they shared the terrible weight of leading their people through a great war. They were also good friends.

  Driving his blue Ford Phaeton, which featured special hand-controlled levers to accommodate his physical disability, Roosevelt whisked his guest off on a hair-raising tour along the Hudson River bluffs. For two hours they spoke of the war, and Churchill was encouraged by how much more they settled zipping across the estate than they would have done on opposite sides of a crowded conference table.

  Earlier that week, Roosevelt had read through a report that set out a plan for a massive U.S. Army program to build atomic bombs. His chief scientific adviser, Vannevar Bush, who’d founded Raytheon, was spearheading the effort, with an estimated cost of $500 million.

  The program’s genesis mirrored in many ways the British Tube Alloys program. In August 1939 Albert Einstein, in contact with a group of scientists who had recently emigrated from Europe, sent a letter to Roosevelt warning of the need to exploit the explosive potential of fission before the Germans did. A “Uranium Committee” of leading physicists was formed, and over the next two years, with limited funds but a lot of ambition, they conducted research, welcomed insight from the British, and concluded that a devastating new weapon was indeed possible—and that there were several potential routes to success. By summer 1942, word had come from Europe that the Germans might have already realized a working nuclear reactor—something the United States had yet to achieve. As one scientist wrote Bush, urging a decisive American effort, “Nobody can tell now whether we shall be ready before German bombs wipe out American cities.”

  With a handwritten note that simply read “Ok. V.B.,” Roosevelt approved the development of the program, which was codenamed the Manhattan Project. In typical American bigger-is-better fashion, its leaders decided that every route to a bomb should be pursued, including using heavy water reactors, plutonium, and U-235 isotope separation.

  On June 20, Roosevelt and Churchill held a meeting in a small, dark study that faced the front porch of the Hyde Park mansion. Once Roo-sevelt’s children had used the space as a classroom, but now it was his quiet hideaway, with bookshelves and nautical prints on the walls and a huge oak desk that took up most of the space.

  Churchill sat, a globe beside his feet, and got straight to the point. “What if the enemy should get an atomic bomb before we did!” he later wrote, recounting the meeting. “However skeptical one might feel about the assertions of scientists, much disputed among themselves and expressed in jargon incomprehensible to laymen, we could not run the mortal risk of being outstripped in this awful sphere.” Their two countries needed to “pool our information, work together on equal terms, and share the results, if any, equally between us.” If Churchill expected a debate, he didn’t get one. Roosevelt agreed wholeheartedly with the proposal, and given the ongoing Nazi bombing raids on Britain, they decided that the United States should be the center of activity.

  They also discussed the German focus on producing heavy water—“a sinister term, eerie, unnatural,” Churchill later said. A few days after the prime minister flew back to London, the War Cabinet put forward plans, of the highest priority, for a raid on Vemork.

  Part II

  6

  Commando Order

  * * *

  JENS-ANTON POULSSON, a Rjukan native, wanted a mission—and if his commanders would not give him one, he would come up with his own. He had nearly circumnavigated the globe to come to Britain to join Kompani Linge, and since his arrival in Britain in October 1941 he had heard a lot of plans but seen no execution. His best prospect had been to lead one of the six teams in Operation Clairvoyant, his task specifically to guide nighttime bombers toward the Vemork power station by setting out lights in the Vestfjord Valley. But then that operation was abandoned and, as he wrote in his diary, “the greatest opportunity of my whole life” slipped away.

  Thus in late February 1942 Poulsson traveled down from Scotland to p
itch his bosses in London a new plan. Meeting with a member of Colonel Wilson’s staff, Poulsson proposed the idea of a small team that would organize resistance cells around Telemark and prepare to sabotage railway lines. He drafted the details in a report, then returned to Scotland while the plan was considered.

  Weeks passed and no answer came. He was sent on a training scheme to attack an airport. Then in early April he got orders to go to STS 31, the “finishing school” at Beaulieu, a forested estate in southern England. Over the next three weeks, he received training in espionage and living an underground life. He learned how to develop a cover (“Your story will be mainly true”); shadow a target; recruit informants (“A few drinks may be helpful”); build up an underground cell; establish a covert headquarters; and thwart counterespionage efforts, including losing a tail (“Lead him through a long deserted street and then plunge into a crowd”), staying alert (“A familiar voice or face suggests an agent is being followed”), and manufacturing a good alibi. His instructors taught him how to surveil a target, to merge into the background on a street, to burgle a house, to open handcuffs, to read a room for a quick escape. He became skilled in leaving hidden messages, in microphotographs, ciphers, and invisible inks. It was all very different from the kind of warfare he’d imagined.

  He studied the enemy, everything from its organizations, uniforms, and regulations to its detective measures, wireless-interception abilities, and interrogation techniques. If he was ever to find himself under questioning, his lecturers said, “Create the impression of an averagely stupid, honest citizen.” The school’s commander, Major Woolrych, told his students, “Remember: the best agents are never caught. But some agents . . . they are inclined to relax their precautions. That is the moment to beware of. Never relax. Never fool yourself by thinking the enemy are asleep. They may be watching you all the time, so watch your step.”