CHAPTER ELEVEN

CONSTRUCTION

THE MET LAB SCIENTISTS had negotiated the first hurdle in the race for the bomb. With the nation ill-prepared for war, millions of tons of steel, copper, concrete and other materiel that would otherwise have been used to build ships and planes and tanks were diverted to building the bomb. President Truman would later call the decision to build the atom bomb “the greatest scientific gamble in history.” 95

Ever since Archimedes designed the first catapult for use against the Romans, warring nations had looked to scientists and engineers to build ever more lethal weapons. The atom bomb would be unlike any device ever invented. If it worked, if it could be built in time to use during the war, it would be the greatest leap in destructive power in the history of warfare, dwarfing all other weapons. Armed with such a weapon, a single bomber could strike a blow that previously would have required 2,000 bombers dropping more than 150 thousand 500-pound bombs. 96

The United States had gotten a late start, but it was now fully committed to beating the Germans. Everyone understood that whoever got to the finish line first could not only win the war, but also reverse a defeat. In the longer run, if Hitler obtained an atom bomb, he could extend Nazi power across the globe. The world would be dominated by his Nazi social policies of forced sterilization, euthanasia and genocide—policies designed to create a racially pure state—for years, perhaps centuries. In the future, every Jew in the world would be at risk of death. It would be a horror show.

THE HILLS AND VALLEYS of eastern Tennessee echoed with the sound of bulldozers and jackhammers racing to clear land for U235 separation plants. It was the spring of 1943. In an 80,000-acre area later named Oak Ridge, railroad workers rushed to lay tracks for the hundreds of railcars hauling thousands of tons of uranium ore for processing.

Fermi needed 93,000 pounds of natural uranium containing a mix of U238 and U235 atoms to generate half a watt of energy. If all went as planned, Oppenheimer would use just 135 pounds of nearly pure U235 atoms to trigger an atomic explosion.

To harvest those 135 pounds Manhattan Project engineers would have to process thousands of tons of uranium ore. It would be a monumental undertaking, and there was no proven method for doing it. Manhattan Project officials had to gamble on two technologies that had never been used for the purpose. The separation plants were enormous. The machinery for the first technology, gaseous diffusion, would fill a six-story plant that stretched half a mile and encompassed 2,000,000 square feet. The giant magnets for the second technology, mass spectrometry, would cover an area larger than twenty football fields. (In June 1944, with the gaseous diffusion plagued by problems, Oppenheimer and General Groves would authorize a crash effort to build yet another separation plant, this one using thermal diffusion technology.) 97

After the war, the adjectives “mammoth,” “monumental,” “enormous,” and “giant” would all be used to describe the fuel processing plants, but none seemed adequate.

While workers at Oak Ridge rushed to build U235 processing plants, across the country surveyors on a desolate, windswept tract of real estate half the size of Rhode Island raced to map a site for the production of plutonium. This new town, Hanford, Washington, would serve three nuclear reactors and chemical separation plants. The separation plants were so large the army of workers building them named them “Queen Marys” after the giant flagship of Cunard ocean liners.

General Groves contracted with dozens of companies to build the facilities at Oak Ridge and Hanford, imposing impossible deadlines that forced them to design and build simultaneously, and then begin operations even before construction was completed. General Groves would later admit, “Never in history has anyone embarking on an important undertaking had so little certainty about how to proceed as we had then.” 98