Silverplate

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 in November 1943 on a prototype Silverplate B-29 known as the "Pullman", which was used for bomb-flight testing at Muroc Army Air Field in California beginning in March 1944. The testing led to further modifications of the bombs and the aircraft. After the Pullman, Silverplate bombers were ordered in three batches: 17 ordered in August 1944 to allow the 509th Composite Group to train with the type of aircraft they would fly in combat and for the 216th Army Air Forces Base Unit to test bomb configurations. 28 ordered in February 1945 for operational use by the 509th Composite Group. This batch included the aircraft that would be used in the August 1945 atomic bombings of Hiroshima and Nagasaki. 19 ordered in July 1945, delivered between the end of the war and the end of 1947. The use of the Silverplate codename was discontinued after the war, but modifications continued under a new codename: Saddletree. Another 80 aircraft were modified under this program. The last group of B-29s was modified in 1953 but never saw further service.