The proposal cleared the Military Policy Committee on June 12, 1944. On June 18 Groves contracted with the engineering firm of H. K. Ferguson to build a 2,100-column thermal-diffusion plant beside the power plant on the Clinch River in ninety days or less. That extraordinary deadline allowed no time for design. Ferguson would assemble the operation from twenty-one identical copies—“Chinese copies,” Groves called them—of Philip Abelson’s 100-column unit in the Philadelphia Navy Yard.
