Atomic weapon in the context of "W54"

Silverplate was the code reference for the United States Army Air Forces' participation in the Manhattan Project during World War II. Originally the name for the aircraft modification project which enabled a B-29 Superfortress bomber to drop an atomic weapon, "Silverplate" eventually came to identify the training and operational aspects of the program as well. The original directive for the project had as its subject line "Silver Plated Project," but continued usage of the term shortened it to "Silverplate".

Testing began with scale models at the Naval Proving Ground in Dahlgren, Virginia, in August 1943. Modifications began on a prototype Silverplate B-29 known as the "Pullman" in November 1943, and it was used for bomb flight testing at Muroc Army Air Field in California commencing in March 1944. The testing resulted in further modifications to both the bombs and the aircraft.

The Office of Scientific Research and Development (OSRD) was an agency of the United States federal government created to coordinate scientific research for military purposes during World War II. Arrangements were made for its creation during May 1941, and it was created formally by Executive Order 8807 on June 28, 1941. It superseded the work of the National Defense Research Committee (NDRC), was given almost unlimited access to funding and resources, and was directed by Vannevar Bush, who reported only to President Franklin Delano Roosevelt.

The research was widely varied, and included projects devoted to new and more accurate bombs, reliable detonators, work on the proximity fuze, guided missiles, radar and early-warning systems, lighter and more accurate hand weapons, more effective medical treatments (including work to make penicillin at scale, which was necessary for its use as a drug), more versatile vehicles, and, the most secret of all, the S-1 Section, which later became the Manhattan Project and developed the first atomic weapons.