Oppenheimer's Plan
Lab Organized to Focus on Mission
The Laboratory's first director, J. Robert Oppenheimer, organized the Laboratory into four technical divisions and two oversight committees: Ordinance (E), Chemistry and Metallurgy (C, but very quickly CM), Experimental Physics (P), Theoretical Physics (T), the Governing Board, and the Coordinating Council.
Each division was headed by a division leader who reported directly to Oppenheimer. The divisions were subdivided into groups, with each group identified by its division letter code and a number. The Governing Board handled policy matters between divisions, senior Laboratory managers, and Manhattan Engineering District headquarters. The Coordinating Council supervised the operational work of both groups and divisions.
Between April 1943 and August 1944, the majority of the technical work focused on using a large caliber gun to shoot one piece of uranium or plutonium at a second piece of the same material. However, experiments by future Nobel Laureate Emilio Segre proved that plutonium could not be used in a gun because residual impurities could not be totally removed. An alternate method, implosion, had to be developed if plutonium was to be used.
Reorganization Focuses on Implosion
Oppenheimer reorganized the Lab in August 1944 to concentrate Laboratory work on implosion. Two new divisions were created to develop the implosion weapon: Weapon Physics (G) and Explosives (X). T and CM Divisions remained relatively unchanged. Work on a gun to assemble uranium was concentrated in a restructured Ordnance Division (O). P Division was disbanded and replaced by the Research Division. Fermi (F) Division was created to study reactors, thermonuclear reactions, and specialized fission reactions.
With the increasing complexity and interlocking activities of the Laboratory, Oppenheimer also created two associate director and two assistant director positions to handle the increasing administrative workload: Associate Director for Ordnance, Assembly, Delivery, and Engineering; Associate Director for Nuclear Physics; Assistant Director for Personnel and Assistant Director for Procurement.
Committees Coordinate Research
The use of committees to provide oversight and coordination of Laboratory work also changed in the summer of 1944. The Governing Board was replaced by the Administrative Board and the Technical Board, whose responsibilities mirrored their names. As work on implosion progressed, the Technical Board was replaced by the Intermediate Scheduling Conference, which coordinated the design and testing of the implosion bomb, as well as the Technical and Scheduling Conference, which coordinated experiments, shop time, and the use of fissionable material.
Even with these changes, the implosion program continued to require increasing oversight and coordination. Consequently three new committees were created in 1945. The Cowpuncher Committee, organized to "ride herd" on the implosion program, provided overall executive direction. The Detonator Committee and the Initiator Committee provided operational support for the development of these crucial parts of the implosion weapon.
Projects Test Nuclear Devices
In March 1945 two new projects were created to handle the proof test of the implosion device and the combat use of both Little Boy and Fat Man. Project Trinity (TR) handled the successful test of the implosion device that took place on July 16, 1945. Project Alberta (A) managed the movement of the men and material to the Pacific Island of Tinian and assembled both Little Boy and Fat Man for their combat use against Japan. The work of Project A was handled, for the most part, by the Ordnance (O) Division. Remaining O Division activities at Los Alamos were handled by a new ordnance Division (Z). Z Division moved to Sandia Base in Albuquerque and ultimately became Sandia Corporation.