Jack Hefner joined the Manhattan Project at Oak Ridge in 1943. Hefner was a reactor engineer and helped supervise the construction of the X-10 Graphite Reactor. Later, he transferred to Hanford and worked as a shift engineer, where he monitored the B Reactor. Hefner also helped maintain Hanford's sprawling facilities, including office buildings and houses in the 700 Area.
Reactor EngineerTinian IslandListen to Jack Hefner's Oral History on Voices of the Manhattan Project
Jack Hefner's Timeline
1943 Joined the Manhattan Project at Oak Ridge.
Philip M. Barnes
Philip M. Barnes served as a lieutenant in the 1st Ordnance Squadron. He was the assistant weaponeer on Bockscar during the Nagasaki bombing mission.