
The B83 nuclear gravity bomb
The 'B83'
nuclear weapon is a
variable-yield gravity bomb developed by the
United States in the late
1970s, entering service in
1983. It was based partly on the earlier
B77 program, which was terminated due to cost overruns. The first underground test detonation took place on
15 December 1984. It was designed at
Lawrence Livermore National Laboratory.
The B83 replaced several earlier weapons, including the
B28,
B43, and ultra-high yield
B53. It was the first U.S. nuclear weapon designed from the start to avoid accidental detonation, with the use of 'insensitive' explosive in the trigger lens system. Its internal design and layout are similar to the smaller
B61, with the
warhead mounted in the forward part of the weapon to make the bomb deliberately nose-heavy. It was intended for high-speed carriage (up to
Mach 2.0) and delivery at either high or low altitude. For the latter role, it can be equipped with a parachute retardation system, with a 46 ft (14 m)
Kevlar parachute capable of rapid deceleration. It can be employed in free fall, retarded, contact, or
laydown modes, for either
airburst or
ground burst detonation.
The bomb is 12 ft (3.67 m) long, with a diameter of 18 in (457 mm). It weighs approximately 2,400 lb (1,089 kg). It has a
variable yield: the destructive power is adjustable from somewhere in the low
kiloton range up to a maximum of 1.2
megatons.

A B83 casing.
The 'B83' can be deployed by a wide range of U.S.
aircraft including:
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B-1B
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B-2
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B-52
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F-15
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F-16
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F-18
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F-22
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A-6
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A-7
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AV-8B
About 650 B83s were built, and the weapon remains in service as part of the United States "
Enduring Stockpile."
Earth-penetrating warheads
The B83 is one of the weapons which has been considered for use in the
Robust nuclear earth penetrator program, otherwise known as
Nuclear bunker buster. While most efforts have focused on the smaller
B61-11 nuclear bomb,
Los Alamos National Laboratory was also analyzing the use of the B83 in this role.
This weapon has been considered for use against any Near Earth Asteroids, with six weapons being used to 'knock' an asteroid off course, should it pose a risk to the earth.
As of early 2006, the RNEP program has been halted by Congress.
See also
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B61 nuclear bomb
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List of nuclear weapons
External links
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B83 Information Site
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B83 page at nuclearweaponarchive.org
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NASA proposal to attack asteriods