The Manhattan Project: Making the Atomic Bomb

Clinton Engineer Works (Oak Ridge)

By the time President Roosevelt authorized the Manhattan Project on December 28, 1942, work on the east Tennessee site where the first production facilities were to be built was already underway. The final quarter of 1942 saw the acquisition of the roughly ninety-square-mile parcel (59,000 acres) in the ridges just west of Knoxville, the removal of the relatively few families on the marginal farmland, and extensive site preparation to provide the transportation, communications, and utility needs of the town and production plants that would occupy the previously underdeveloped area. Original plans called for the Clinton Engineer Works, as the military reservation was named, to house approximately 13,000 people in prefabricated housing, trailers, and wood dormitories. By the time the Manhattan Engineer District headquarters were moved from Washington to Tennessee in the summer of 1943 (Groves kept the Manhattan Project's office in Washington and placed Nichols in command in Tennessee), estimates for the town of Oak Ridge had been revised upward to 40-45,000 people. (The name Oak Ridge did not come into usage until after World War II but will be used here to avoid confusion). At the end of the war, Oak Ridge was the fifth largest town in Tennessee, and the Clinton Engineer Works was consuming one-seventh of all the power being produced in the nation.²⁹ While the Army and its contractors tried to keep up with the rapid influx of workers and their families, services always lagged behind demand, though morale remained high in the atomic boomtown.

The three production facility sites were located in valleys away from the town. This provided security and containment in case of explosions. The Y-12 area, home of the electromagnetic plant, was closest to Oak Ridge, being but one ridge away to the south. Farther to the south and west lay both the X-10 area, which contained the experimental plutonium pile and separation facilities, and K-25, site of the gaseous diffusion plant and later the S-50 thermal diffusion plat. Y-12 and X-10 were begun slightly earlier in 1943 than was K-25, but all three were well along by the end of the year.

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