W84

The W84 is an American thermonuclear warhead designed for use on the BGM-109G Gryphon Ground Launched Cruise Missile (GLCM). It is a derivative of the B61 nuclear bomb design and a close relative of the W80 warhead used on the AGM-86 ALCM, AGM-129 ACM, and BGM-109 Tomahawk SLCM cruise missiles.

The W84 is a two stage radiation implosion warhead with a variable yield ranging from 0.2 kiloton up to 150 kilotons.

The W84 was designed at Lawrence Livermore National Laboratory starting in 1978, based on the B61 nuclear bomb weapon design originated at Los Alamos National Laboratory. Manufacture of this warhead commenced in 1983. Sources differ regarding the total number of units produced, though the figure is known to be either 350 or 530.

The W84 is 13 inches in diameter and 34 inches long, slightly wider and longer than the W80 warhead used on air-launched and submarine-launched cruise missiles. It weighs 388 pounds, almost 100 pounds heavier than the W80.

The W84 has all eight of the modern types of nuclear weapon safety features identified as desirable in nuclear weapon safety studies. It is the only US nuclear warhead which has all eight features. These include: insensitive, TATB based plastic bonded high explosives; Fire Resistant Pit; Enhanced Nuclear Detonation Safety (ENDS/EEI) with detonator stronglinks; Command Disable; and the most advanced Permissive Action Link (PAL G).

The W84 warheads are in Enduring Stockpile storage; the GLCM missiles which previously carried them have been destroyed to comply with the INF treaty, but the warheads are being maintained in case a future application is required.