National Museum of Nuclear Science & History
Arnold Grubbe (1904-2002) was an engineer working for the civilian contractor Crane Company in Oak Ridge, Tennessee.
Harold Hoover was a member of the Special Engineer Detachment during the Manhattan Project. He worked as a filter foreman at the Y-12 Plant, but his real job was in counterintelligence, to ensure no sabotage occurred.
Lawrence Sperry worked for the United States Engineer District Office.
