Parsons was in charge of scientists and technicians from Project Alberta on Tinian, who were nominally organized as the 1st Technical Service Detachment. Their role was the handling and maintenance of the nuclear weapons. Parsons was joined by Purnell, who represented the Military Liaison Committee, and Brigadier General Thomas F. Farrell, Groves' Deputy for Operations. They became, informally, the "Tinian Joint Chiefs", with decision-making authority over the nuclear mission. Before Farrell left for Tinian, Groves had told him: "Don't let Parsons get killed. We need him!"
