IN MID-APRIL 1943, a military truck drove across the suspension bridge into Vemork. Secured in the truck bed was what looked like a steel drum of ordinary potash lye, an ingredient in the electrolysis process. What the drum actually contained was 116 kilograms of almost pure heavy water from Berlin. It had been originally produced at Vemork.
Soon after the sabotage on February 28, a stream of Norsk Hydro company men and German officials had come to the plant to decide its fate. Some argued that all the salvageable equipment be shipped to Germany, since destroying the plant had virtually become a “national Norwegian sport.” Others, including Bjarne Eriksen, the Norsk Hydro director general, wanted to start up again at Vemork. Esau and the Army Ordnance Office were asked for a “swift decision,” which they delivered: the cells should be repaired and the plant expanded as soon as possible. Heavy water facilities at Såheim and Notodden should also be completed. The German command provided any materials and manpower required (including slave labor from abroad) and warned that if the work was not completed quickly enough, there would be severe reprisals.
By the time the secret shipment of heavy water from Berlin arrived at Vemork, the round-the-clock work on the plant was almost complete. The shipment was used to fill the new high-concentration cells, overriding the slow process of accumulating the precious substance drop by drop, and accelerating the return to production by several months. With three new stages and a number of cells added to the preliminary electrolysis process as well, the Germans projected that daily output would soon reach 9.75 kilograms. Given the plans to double the size of the high-concentration plant yet again, the daily yield might reach almost 20 kilograms within the year.
While this was going on, SS officer Muggenthaler and Lieutenant Wirtz, the new head of guard at Vemork, finalized the security measures. Another guard was placed at the suspension bridge and two more at the railway gate. Others patrolled the grounds with Alsatian dogs night and day. Sappers laid more mines on every approach. Barbed-wire fences were raised. To defend against an air attack, additional wires were strung across the valley, and fog-producing machines were placed about the area. The pipelines were camouflaged, and torpedo nets were set up to protect the Lake Møs dam. A permanent guard was posted outside the rebuilt high-concentration plant. All the doors but one, which was reinforced with steel, were bricked up or sealed with wooden planks. The windows were similarly blocked off or fixed with iron bars and wire mesh. Within the plant, a team of guards was armed with submachine guns.
Muggenthaler weeded out any employees perceived to be a threat, and German technicians took on roles within the facility to spy on any illicit activity. Vemork may have been a fortress before, but now its high-concentration plant was a fortress within a fortress. And on April 17, 1943, at 2:00 p.m., heavy water began to flow securely through the cascade of cells.
*
Three weeks later, on May 7, the Uranium Club met at the Reich Physical and Technical Institute in Berlin. The scientists were under pressure for results like never before. With German fortunes in the war deteriorating, the Allies set to retake all of North Africa, and the Soviets continuing to defeat the Wehrmacht on the Eastern Front, the Nazi brass felt a desperate desire for something that would quickly turn the tide in their favor. One report stated that “rumors abound in the general German population about a new-fangled bomb. Twelve such bombs, designed on the principle of demolishing atoms, are supposedly enough to destroy a city of millions.” Worse yet, Abwehr intelligence had revealed that the Americans were on the path to creating “uranium bombs.” The German atomic program was riven by factions, and its scientists and research centers now exposed to attack by Allied bombing. They needed a breakthrough to focus their efforts.
The first item on the agenda for the May 7 meeting was heavy water. Only the previous day, at a German Academy of Aeronautical Research conference, Abraham Esau had placed part of the blame for their slow atomic progress on the recent lack of heavy water. He wanted to press ahead with production in Germany, the plans for which had long been stalled because of the cheap supply from Norway. Paul Harteck advised that after a few more experiments, the Leuna pilot plant, using his catalytic exchange process, could likely be expanded to produce five tons a year, if they fed it with slightly enriched water from Vemork or a couple of Italian electrolysis plants. He also suggested that they try another method, invented by Klaus Clusius, which capitalized on the slightly higher boiling point of heavy water to produce enriched amounts. Esau gave the go-ahead on the preliminary work for Leuna and charged Harteck with determining whether the Clusius method made sense on an industrial scale. But with Vemork back online, and these additional projects, Esau felt confident they would soon have all the heavy water they needed.
Diebner was less sure there was enough to go around. He made it clear that he needed every drop for his next two experiments. His team’s most recent uranium machine (G-II), which used uranium metal cubes suspended in frozen heavy water, showed neutron production at a level one and a half times greater than any German experiment so far. The machine proved that a cube design was far superior to any other in fostering a chain reaction, he said, and at the right size, it would likely be self-sustaining.
Heisenberg disagreed. In his mind, the best design was still an open question. He claimed the dimensions of his latest machine, a sphere with alternating layers of uranium metal and heavy water, were “too small to yield absolutely certain values.” But he added that the company producing uranium metal for them was already casting it in plates, like he needed, rather than cubes, as Diebner demanded. Thus his experiments — and the heavy water they required — should be first in line. “This doesn’t rule out a subsequent cube experiment, if one is needed,” Heisenberg offered condescendingly.
The tension in the room was palpable. Diebner had his supporters, including Harteck, who believed that Heisenberg was blind to the value of any experiment that did not originate from his own brain. Esau, who had appropriated heavy water from Heisenberg for Diebner’s latest experiment, said he needed to think further about whose work should be given precedence. Eventually both men received a share of heavy water and uranium to allow them to proceed with small-scale experiments, but both were left dissatisfied.
*
General Leslie Groves was worried. And he was not a man to leave a worry to fester for long. The graduate of West Point and MIT was just shy of six feet tall, with a blocky head, a thick sweep of brown hair, and a barrel of a chest to accommodate his medals. Groves was known as a “doer, a driver, and a stickler for duty.” Charged with running the Manhattan Project, he was also regarded by some of his staff as the “biggest sonuvabitch” they had ever worked for: critical, abrasive, and egotistical. Those same people would have wanted nobody else to lead the American project to beat Germany to the bomb.
As Groves saw it, there were two complementary ways to achieve that end: first, to accelerate the U.S. effort and, second, to slow down the enemy. For the former, he led a full-throttle campaign that employed tens of thousands of scientists, engineers, and workers and drew on hundreds of millions of dollars. In the hills of Tennessee, monumental plants were being built to separate the rare isotope U-235 from U-238 using two different methods. Beside the Columbia River in Washington State, construction had commenced on reactors that used two hundred tons of uranium moderated by twelve hundred tons of graphite. Working with their Canadian ally, the Americans were building a massive heavy water plant at a hydropower station in Trail, British Columbia. At the Los Alamos Ranch School in New Mexico, a small city of physicists was working to build a functioning fission bomb. All these efforts brought worry, but at least they were under Groves’s direct control.
Slowing the enemy down was not. First, he had limited intelligence about German advances. Second, he did not have authority over operational forces or bombers to direct them to enemy targets. At the end of March, he learned — from a Swedish newspaper, no less — of the success of the British sabotage operation against Vemork in Norway, a plant that he had long known provided the German program with critical re-sources.
Through the Army chief of staff, General George Marshall, and Field Marshal John Dill, the lead British military representative in Washington, Groves demanded to know the details of the operation. In April he was told that the plant would be inoperable for two years. Then, only days later, he was informed that this period had been reduced to one year.
A short while after, Michael Perrin told him that the Germans would not realize the bomb before war’s end. Perrin, one of the leaders of the British Tube Alloys Committee, was on a visit to Washington at the time. “You might be right,” Groves replied. “But I don’t believe it.” Even if Perrin were correct, Groves knew that there were other dangers — one of which was a radioactive attack.
From a detailed report produced by his scientists, he learned that if the Germans succeeded in starting a heavy water reactor, they could easily produce “colossal amounts” of radioactive substances that could be dropped over a city. Although the report concluded that there were challenges to creating an effective radioactive bomb, the Germans could, at the very least, “completely incapacitate” a city like London, requiring large sections of it to be evacuated.
On the morning of June 24, 1943, Groves convened with Vannevar Bush, the blue-eyed, beanpole New Englander who served on the committee that oversaw the Manhattan Project. The two men went over the progress of the program, including the likelihood that they would have at least one bomb ready to be deployed by early 1945. They also reviewed a list of targets to be attacked in order to slow down the German project, targets pointed out with the help of British intelligence — and Leif Tron-stad. These included Vemork and several German research centers. Groves and Bush agreed there was no sense in spending half a billion dollars to produce a bomb if they did not “strain every nerve on the countermeasure side.”
A few hours later, Bush lunched at the White House with President Roosevelt. He outlined how they were “going very aggressively” and were on schedule for a January 1, 1945, delivery of a bomb. Roosevelt wanted to know where the Germans were. Bush answered that the Nazi scientists were “doing serious work on this before we were and that they might therefore be ahead of us.” However, “arrangements were under way” to hit the few German targets they had on their list.
When Roosevelt gave his assent, Groves put his wrecking-ball force of will into seeing this was done.
*
Earlier in the summer, Knut Haukelid was in the Oslo apartment of Trond Five, resistance leader and an old family friend, when there was a knock on the door. Trond went to open it, and Haukelid heard the distinctive voice of his own father, Bjørgulf. Quickly, he hid in the next room, sticking to one of the fundamental rules of illegal work: never make contact with family. As far as any of them knew, he was still in Britain. In almost two years, he had neither seen nor spoken with anybody in his family, including his wife, Bodil. Her involvement in the resistance had forced her to leave for Sweden in mid-March.
Now that his father was only a few feet away, separated only by a door, Haukelid wanted to break the rules, to step into the room, to embrace his dad. They may not have always seen the world in the same way, but they were still father and son. Resisting the temptation, Haukelid remained hidden. After some brief words, Trond sent the surprise visitor away.
Haukelid and Kjelstrup spent several weeks in the capital city, resting up and waiting for new identity cards in the names of Nasjonal Samling members. While there, they learned that Helberg had not in fact been killed while attempting to escape, and the happy news of his survival was sent to London. Their friend’s travails reinforced with them how careful they must be at all times — and that there should be no overnight stays in hotels.
In June, they left Oslo to start their underground organization in earnest. They headed back to Vågslid on bikes bought on the black market, acting the part of tourists out for a summer ride and sleeping out in the woods, avoiding hotels.
Their plan was to create a safe base of operations, then Haukelid would recruit several district commanders to lead their own cells and assemble resistance fighters. As these commanders would be the only ones to know of his existence, they had to be absolutely trustworthy. Once trained and armed, the underground organization would lie in wait, ready to carry out guerrilla attacks that would sap their enemy’s strength and inhibit their movement through the district’s important east–west corridor from Oslo to the North Sea.
Haukelid and Kjelstrup built their base high in the mountains southwest of Vågslid, up from Lake Holme. They gathered moss-covered stones to make a double-walled cabin that would look like just another pile of stones from a distance, packing dirt and peat between the walls, making them impermeable to the wind. For the door and roof beams, they salvaged wood from an abandoned mine to the south. When they were hungry, they fished for trout in the lake. When tired, they lounged in the sun, glad to be free of the winter at last. Haukelid bought an elkhound puppy from a local farmer; they called him Bamse (Little Bear) and named their rising cabin after him, Bamsebu.
Haukelid took a break from the construction to go and meet one of his new platoon commanders. Then he traveled on to a hamlet a few miles northeast of Dalen. On June 18, as planned, he met Skinnarland at the farmhouse of one of their contacts. Skinnarland was in a terrible state. Two weeks before, his baby niece had died, suffocated in her crib. Her father Olav, who was in Grini because of his connection to Einar, could not even attend her funeral. The loss was one tragedy too many for their elderly father, who was now on the verge of death himself, and there was no way Skinnarland could visit him with the Germans stationed so close to the dam. He had been living alone at Nilsbu, suffering from a cracked front tooth that caused him constant pain. Traveling as “Einar Hansson,” a life-insurance inspector, he had emerged from hiding to undergo several procedures with a dentist located outside Dalen. The one in Rjukan was sure to identify him — and potentially turn him in to the Gestapo.
Haukelid managed to comfort Skinnarland, and for the next few nights they tried to forget that they were men on the run. “Bonzo was waiting— very nice meeting,” Skinnarland wrote on the eighteenth in his abbreviated diary. “Big party with eggnog cream — very stately,” he dashed off the next day. “Began at the dentist — fun and games,” was his entry for the day following that. On one of the days they spent together, Haukelid showed Skinnarland a list of Norwegian girls’ names he had found in a book. The names had gone out of fashion long before, but Haukelid liked one in particular: Kirvil. If he ever had a daughter, he said, he would name her that. For a moment, Skinnarland thought of the future too, one in which he might have a wife, children, a whole life beyond this one. He promised Haukelid that if he had a daughter, he would name her Kirvil as well. Shortly after, Haukelid returned to Bamsebu. Skinnarland remained for almost two weeks and several more procedures at the dentist’s.
After one such appointment, as he came back to his hut up from Lake Møs, Jon Hovden, a farmer who was one of his main pillars of support, visited him. Lillian Syverstad had delivered a note from her brother Gunnar for Hovden to give to him. The news contained in the note, Skinnarland knew upon reading it, would have to be sent to London straightaway.
*
On July 8, Tronstad received the disturbing message from Skinnarland: “Vemork reckons on delivering heavy water from about August 15.” Wilson asked him to get confirmation on the report. John Anderson and the War Cabinet would need to be alerted.
Until that point, Gunnerside had been an unqualified success. Their target had been destroyed. Not a shot was fired. There had been no major reprisals. Every single member of the team had escaped to safety, their identities unknown to the Germans. Tronstad could not have dreamed of a better outcome. Praise had come from every quarter, from the Norwegian high command to Churchill himself, who had asked plainly, “What rewards are to be given to these heroic men?” The success had raised the profile of the SOE and its Kompani Linge, giving them more opportunities for future missions in Norway.
If Skinnarland’s report were true, the Germans would have full production back online much sooner than Tronstad had originally thought. Gunnerside may have set back supplies of German heavy water by two tons, half of what they needed for a working reactor, but Tronstad knew any renewed deliveries to Berlin would not be tolerated, particularly after recent statements secreted out from Niels Bohr. After two German physicists visited his lab in Copenhagen, the Danish physicist stated that he believed atom bombs were practicable in the immediate future, particularly if there was enough heavy water on hand to manufacture the necessary ingredients. When asked if heavy water production was “war-important” and whether such plants should be destroyed, Bohr answered yes to both questions. Coming from Bohr, one of the fathers of atomic physics who was soon to be secreted out of Denmark at last, this declaration put the bull’s-eye back on Vemork.
Tronstad sent orders to Skinnarland to investigate progress at the plant. On July 19, Tronstad wrote a lengthy report to SOE on how to “tackle the juice issue” again, as he described it in his diary. More than anything, he wanted to prevent a massive bombing run on the plant like the Americans were urging. He doubted such a bombardment would destroy the basement-level high-concentration plant, which was protected by tons of steel and concrete overhead. Also, such an attack would almost certainly inflict enormous collateral damage, both in terms of the lives of the everyday Norwegians living around the plant, and on the postwar Norwegian economy. Further, he had doubts that the Germans were pursuing the bomb with the fervor suggested by Bohr’s statement. From what Brun had gleaned from his time at Vemork, not to mention recent intelligence Tronstad and Welsh had received from their moles in Sweden, Norway, and Germany, the chances of the Nazis developing a “devil machine” were limited.
In his report, Tronstad advised caution but also gave various options to stop production at Vemork and slow the Nazi atomic effort. They could destroy one of the dams that provided water to its power generators. They could target the transport of heavy water from Vemork to Germany. They could sabotage the high-concentration plant from within. They could hit sites in Berlin where experimental work was taking place or from where it was managed. He even provided the addresses. He did not include a bombing run on Vemork or on the other two plants at Såheim and Notodden, which were either already producing heavy water or were soon to be.
By coincidence, as Tronstad’s list of options for a second attack on Vemork’s heavy water was being circulated within the SOE, he and his men were presented with British awards recognizing their service in the initial attack. On July 21, at Chiltern Court, they assembled in uniform. On behalf of King George VI, Lord Selborne, the minister of economic warfare who oversaw the SOE, awarded Rønneberg and Poulsson the Distinguished Service Order, and the others present (Helberg, Idland, Kayser, Storhaug, and Strømsheim) were given the Military Cross or Military Medal. Tronstad received the Order of the British Empire.
Later, Selborne hosted a dinner for them all at the Ritz Hotel. Appropriately, they were served grouse, gnawing at the bones until they were picked clean. There was much to reflect on — their struggles on the Vidda, the tense moments during and after the sabotage — but still more to laugh over. They recalled their time at a Stockholm hospital, where a pair of Swedish nurses had deloused and scrubbed them clean. Then, once freed from the camp, they had attended La Traviata at the Stockholm opera house like proper civilized people. After the dinner, Tronstad took the men out on the town, the merry group singing songs as they made their way up Piccadilly. Tronstad said nothing of what he had learned from Skinnarland. He did not want to sour the evening.
Not seventy-two hours later, an armada of American heavy bombers from the Eighth Air Force division roared through the clear blue sky over southern Norway. Because of fog over Germany, the bombers had been diverted from a run over Hamburg. Instead they set out to hit several industrial targets in Norway, including the massive new Norsk Hydro aluminum plant at Herøya. They dropped over 1,650 bombs, leveling the area and killing fifty-five people, mostly local workers. Tronstad feared Vemork might be next.