Diana Preston - Before the Fallout

There were, of course, many at Los Alamos only too eager to listen to Bohr. One evening at Oppenheimer’s house, Bohr addressed a small group of European scientists about conditions in Denmark and about his escape. It made a deep impression. As Emilio Segre recalled, “For many of us this was the first eyewitness account of what was really happening in a Nazi-occupied country…. the account left us depressed and worried, and more determined than ever that the bomb should be ready at the earliest date possible.”

Segre would have been relieved to know of the increasing practical difficulties confronting Germany’s scientists. During the summer of 1943 British night bombing attacks on Germany had achieved a new intensity in an operation code-named “Gomorrah.” Aided by the first use of “window”—strips of aluminum foil—designed to confuse German radar when released from bombers—the Royal Air Force had targeted Hamburg. On the night of 27 July the blast of their high-explosive bombs, combined with incendiaries, created a firestorm. Fires merged, sucking air into the center, where the oxygen was burned out. One pilot simply muttered, “Those poor bastards.” Another crewman recalled, “It was as if I was looking into what I imagine an active volcano to be.” Eight square miles of the city were reduced to ashes. Some victims were caught in melting asphalt as they tried to escape. In a raid that lasted only forty-three minutes, forty-two thousand people were killed, including more civilians than died in all German raids on London. Fearing such Allied attacks on Berlin, Albert Speer ordered Germany’s research institutes to seek new and safer homes outside the capital. [32] Sir John Colville, Churchill’s private secretary, related that Air Marshal Harris had shown Churchill a film of the bombing raids on Hamburg and elsewhere, expecting praise for his efforts. When the lights came up, Colville saw tears running down Churchill’s face, and he (Churchill) said, “Are we beasts that we should be doing these things?” However, Churchill’s views on what we would now call “weapons of mass destruction” varied with his mood and the progress of the war. Later, when the German flying bombs were falling on Britain in July 1944, he wrote a memo to his military chiefs of staff: “I want you to think very seriously over the question of using poison gas. I would not use it unless it could be shown that (a) it was life or death for us, or (b) that it would shorten the war by a year. It is absurd to consider morality on this topic when everybody used it in the last war without a word of complaint from the moralists or the Church. On the other hand, in the last war the bombing of open cities was regarded as forbidden. Now everybody does it as a matter of course. It is simply a question of fashion changing as she does between long and short skirts for women.” Churchill, of course, on reflection concluded that gas should not be used.

Heisenberg did not share Speer’s anxiety. Though forced on one occasion to flee through the burning streets of Berlin, shoes smoldering with phosphorus, he believed that his reactor experiments in a concrete bunker in the “Virus House” were well protected. Nevertheless, reflecting that maintaining essential supplies of electricity and water in Berlin might not be possible for much longer, he decided gradually to relocate the Kaiser Wilhelm Institute for Physics to Hechingen, a small town in southwest Germany. Not only was it quite close to Urfeld in the Bavarian Alps, where he had recently moved his family permanently, but, he reckoned, if the worst should come, Hechingen was more likely to fall to invading western Allies than Russians advancing from the east. By the end of 1943 he had sent a third of his institute—those not essential to the fission work—south under Max von Laue as assistant director.

Heisenberg meanwhile continued his work in the Virus House, undeterred by the nighttime wail of the air-raid sirens and the crump of exploding Allied bombs.

SINCE THE RAID on the Vemork heavy water plant in February 1943, Knut Haukelid had been living a precarious existence, organizing resistance groups in the mountains. It had, as he later wrote, been very hard surviving in the wilds of the Hardanger Plateau: “Snow and cold had been our constant companions and we had carried danger with us wherever we went.” Reports that the Germans had immediately started to rebuild the plant perturbed him. Predictably, they had taken precautions against further assault, bricking up doors and windows up to the first-floor level and fortifying entrances with double doors, through which only one person at a time was admitted after scrutiny through a peephole. In addition, they had trebled the guard, floodlit the entire area, and laid new minefields. A further commando raid seemed out of the question.

In the United States General Groves worried about Germany’s continued capacity to manufacture heavy water. He was also angered by Britain’s attitude toward the problem. Before the Gunnerside attack, the head of the Directorate of Tube Alloys, Wallace Akers, had told him that the British were planning to raid Vemork but had revealed no details of how or when. Groves had only learned the outcome from a translation of an article published in the Swedish Svenska Dagbladet on 14 March 1943 reporting that all the apparatus, machines, and facilities for the production of heavy water had been blown up.

Groves’s annoyance grew as the weeks passed and the British still refused to disclose exactly what had happened. He even suggested to his superiors that the U.S. government should buy the information if that was the only way. He was particularly concerned that the plant had not been knocked out permanently. When the British finally furnished sparse details of the raid, claiming that the plant would not be fully effective for more than twelve months, he was unconvinced. A message to London from the Norwegian resistance on 8 July 1943 that the plant was expected to reach full production again by 15 August, which was passed on to him, proved him right.

Groves convinced Vannevar Bush and the army chief of staff, General George C. Marshall, that the plant had to be bombed from the air. The British at first resisted, arguing that casualties among Norwegian civilians would be heavy, but, seeing no other way, bowed to American pressure. On 16 November 1943, 388 B-17s and B-24s of the U.S. Eighth Air Force took off from English airfields, some to make diversionary raids around Oslo, the remainder to target the heavy water complex. Anticipating just such attacks, the Germans had installed antiaircraft batteries and stretched cables from mountain to mountain to hinder low-flying aircraft. As a result, the air assault failed. Only two bombs hit the Norsk-Hydro plant. The heavy water cells were undamaged, but twenty-two Norwegians were killed by stray bombs.

Nevertheless, the attack made the Germans rethink the production of heavy water at Vemork. The risks of further air raids and sabotage were, they decided, too great. They considered manufacturing heavy water in an Italian nitrogen plant and then sending it to Germany for purification but abandoned the idea as too complex. Instead, they decided to ship Vemork’s heavy water to Germany and there construct their own heavy water plant. When Norwegian agents passed rumors of this plan to London, the Special Operations Executive on 29 December sent a message to the Norwegian resistance: “We have information that heavy water equipment may be dismantled and sent to Germany. Can you verify this?… Can this transport be aborted?”

The first question was easily answered. The resistance checked with their contacts at the plant and two days later confirmed to London that the Germans were indeed planning to remove all the stocks of heavy water and the key equipment. Furthermore the move was imminent. The second question was more problematic. The Norwegians told London that they could not yet suggest a plan.