Operation Plumbbob was a significant series of nuclear tests conducted at the Nevada Test Site between May 28 and October 7, 1957. This extensive operation followed Project 57 and preceded Project 58/58A, marking a crucial period in the U.S. nuclear testing program. It involved 29 nuclear explosions, though only two of these did not produce any nuclear yield. The scope of Operation Plumbbob was broad, encompassing various objectives from warhead development
to military effects studies and biomedical research, reflecting the multifaceted nature of nuclear research during the Cold War era.
Diverse Objectives and Extensive Involvement
Twenty-one laboratories and government agencies were involved in Operation Plumbbob, highlighting the collaborative and extensive nature of the program. A primary objective for many of these tests was the development of warheads for intercontinental and intermediate-range missiles. However, the operation also included tests for air defense and anti-submarine warheads, which typically featured smaller yields. This dual focus on strategic and tactical nuclear capabilities demonstrates the comprehensive approach taken by the U.S. military and scientific community at the time.Beyond warhead development, Operation Plumbbob incorporated 43 military effects tests. These studies examined the impact of nuclear explosions on both civil and military structures, providing critical data for defense planning and civil preparedness. Radiation and biomedical studies were also a significant component, investigating the biological effects of nuclear exposure. Additionally, aircraft structural tests were conducted, likely to assess the resilience of military aircraft in a nuclear environment. The operation featured the tallest tower tests in the U.S. nuclear testing program up to that point, alongside high-altitude balloon tests, showcasing a variety of detonation methods and experimental setups.
Groundbreaking Tests and Military Participation
One of the most notable aspects of Operation Plumbbob was the largest troop maneuver ever associated with U.S. nuclear testing. Approximately 18,000 members of the U.S. Air Force, Army, Navy, and Marines participated in exercises Desert Rock VII and VIII. The military's interest in these maneuvers was to understand how the average foot-soldier would physically and psychologically endure the rigors of a tactical nuclear battlefield. This direct involvement of a large number of personnel underscored the military's commitment to preparing for potential nuclear conflict.The operation also included several groundbreaking individual tests. The Pascal-A safety experiment, detonated on July 26, 1957, was the first underground shaft nuclear test. Conducted in an unstemmed hole at the Nevada Test Site, this experiment provided valuable data to predict nuclear yields in case of accidental detonations, such as those resulting from a plane crash. This marked a significant step towards understanding and mitigating the risks associated with nuclear weapons. The Rainier shot, conducted on September 19, 1957, further advanced underground testing by being the first fully contained underground nuclear test. This meant that no fission products were released into the atmosphere. The 1.7 kiloton Rainier test was detectable worldwide by ordinary seismic instruments and became the prototype for subsequent larger and more powerful underground tests, paving the way for future containment strategies.
Unique Experiments and Public Relations
Operation Plumbbob was not without its unique and controversial experiments. Almost 1,200 pigs were subjected to biomedical experiments and blast-effects studies. For instance, during the Priscilla shot (37 kt), 719 pigs were used in various experiments on Frenchman Flat. Some pigs were placed in elevated cages and fitted with suits made of different materials to determine which offered the best protection from thermal radiation. A PBS documentary, Dark Circle, reported that these pigs survived but sustained third-degree burns over 80% of their bodies. Other pigs were positioned behind large sheets of glass at varying distances from the hypocenter to study the effects of flying debris on living targets.In a striking public relations event, the John shot on July 19, 1957, involved the only test of the Air Force's AIR-2A Genie rocket with a nuclear warhead. This warhead was fired from an F-89J Scorpion fighter over Yucca Flats. On the ground, five Air Force officers and a motion picture photographer stood directly under ground zero of the blast, which occurred at an altitude of 18,500 to 20,000 feet. The intention was to demonstrate the possibility of using such a weapon over civilian populations without ill effects. The officers involved were Colonel Sidney C. Bruce, Lieutenant Colonel Frank P. Ball, Major John W. Hughes II, Major Norman B. Bodinger, and Major Donald A. Luttrell, along with videographer Akira "George" Yoshitake. This event underscored the prevailing attitudes and public messaging surrounding nuclear weapons at the time.
