W84

W84. The W84 is an American thermonuclear warhead developed in the late 1970s and produced in the early 1980s. It was designed for deployment on the BGM-109G Ground Launched Cruise Missile, a key component of NATO's intermediate-range nuclear forces in Europe during the Cold War. The warhead's development and deployment were directly tied to the geopolitical tensions of the era, culminating in its retirement following the Intermediate-Range Nuclear Forces Treaty.

Design and development

The W84 was designed by scientists and engineers at the Lawrence Livermore National Laboratory in California, drawing upon previous weapons physics research from programs like the W62 and W70. Its development was initiated to provide a modern, variable-yield warhead for the new BGM-109G Ground Launched Cruise Missile, which was itself part of a broader United States Department of Defense and NATO strategy to counter the deployment of the Soviet SS-20 Saber missile. The design phase involved extensive computer modeling and non-nuclear testing at facilities like the Nevada National Security Site, focusing on achieving a reliable secondary stage for its thermonuclear design while meeting stringent size and weight constraints for air-launched delivery.

Specifications

The warhead is a compact, two-stage radiation-implosion thermonuclear device. It features a variable yield, adjustable from approximately 0.2 kilotons up to 150 kilotons, providing operational flexibility for various targeting scenarios. The physics package is encased in a warhead section designed to integrate with the aerodynamics and guidance systems of the BGM-109G. Key internal components include a plutonium pit primary, a lithium deuteride secondary, and an Argonne National Laboratory-designed FMU-139 fuze and firing set. Its overall dimensions and weight were optimized for carriage by the cruise missile without compromising the weapon's range or stealth characteristics.

Deployment history

Full-scale production of the W84 began in 1983, with warheads subsequently mated to their delivery systems. The BGM-109G missiles, armed with the W84, were deployed to operational bases in several NATO member countries, including the United Kingdom, West Germany, Italy, and Belgium, beginning in late 1983. This deployment was a direct response to the ongoing Euromissile crisis and was a central point of contention in arms control negotiations between the United States and the Soviet Union. The entire system was rendered obsolete by the signing of the Intermediate-Range Nuclear Forces Treaty in 1987, which mandated the elimination of all such ground-launched missiles and their warheads. All W84 warheads were withdrawn from Europe and placed in inactive storage in the U.S. national stockpile.

Safety and security features

The W84 incorporated several advanced safety features known as Enhanced Nuclear Detonation Safety. It utilized a unique stronglink/weaklink system designed to prevent accidental detonation, requiring specific environmental cues from the missile's flight profile to arm. The warhead included a Command Disablement System, allowing for remote electronic disabling if the missile or warhead was at risk of being captured or compromised. These features were tested extensively at sites like the Pantex Plant and the Sandia National Laboratories, which were responsible for final assembly and safety certification. The security during transport and storage followed protocols established by the Department of Energy and the United States Air Force.

Variants

There were no distinct production variants of the W84 deployed. However, the design itself is considered a variant or descendant of the earlier W85 warhead developed for the Pershing II missile, with both designs sharing common technological origins and safety concepts from the same era of American nuclear weapon development. Some non-nuclear test versions, such as inert hydrodynamic test units, were produced for evaluation purposes. The warhead's design philosophy and safety architecture influenced subsequent programs managed by the National Nuclear Security Administration, including elements seen in the B61 Mod 12 life-extension program.

Category:American nuclear warheads Category:Cold War nuclear weapons of the United States Category:Nuclear weapons of the United States