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The B83 is a variable-yield thermonuclear gravity bomb developed by the United States in the late 1970s that entered service in 1983. With a maximum yield of 1.2 megatonnes of TNT (5.0 PJ), it has been the most powerful nuclear weapon in the United States nuclear arsenal since October 25, 2011 after retirement of the B53.[1] It was designed by Lawrence Livermore National Laboratory.[2]

B83
B83 with unclassified components at front
TypeUnguided bomb
Service history
In service1983–present
Used byUnited States
Production history
DesignerLawrence Livermore National Laboratory
No. built650
Specifications
Mass2,400 pounds (1,100 kg)
Length12 feet (3.7 m)
Diameter18 inches (46 cm)

Blast yield1.2 megatonnes of TNT (5.0 PJ)
A B83 casing.

History

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The B83 was based partly on the earlier B77 program, which was terminated because of cost overruns. The B77 was designed with an active altitude control and lifting parachute system for supersonic low-altitude delivery from the B-1A bomber. B77 nuclear component test firings were attributed to the Operation Anvil series in 1975 and 1976, specifically the "Cheese" test shots in Anvil:[2]

The B83 nuclear components have been attributed as the same as the earlier B77.

The B83 replaced several earlier weapons, including the B28, B43, and to some extent the 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 explosives" in the trigger lens system. Its layout is similar to that of the smaller B61, with the warhead mounted in the forward part of the weapon to make the bomb nose-heavy. It was intended for high-speed carriage (up to Mach 2.0) and delivery at high or low altitude. For the latter role, it is equipped with a parachute retardation system, with a 46-foot (14 m) Kevlar ribbon parachute capable of rapid deceleration. It can be employed in free-fall, retarded, contact, and laydown modes, for air-burst or ground-burst detonation. Security features include next-generation permissive action link (PAL) and a command disablement system (CDS), rendering the weapon tactically useless without a nuclear yield.[2]

The B83 was test fired in the Grenadier Tierra nuclear weapon test on 15 December 1984, at a reduced yield of 80 kilotonnes due to the Threshold Test Ban Treaty.[2]

With the dismantling of the last B53 bomb in 2011, the B83 became the highest yield nuclear weapon in the U.S. arsenal.[3] In 2022, the Biden administration announced plans to retire the B83.[4] The B61-13 is planned to replace the B83. Although its yield is lower at 360 kilotonnes of TNT (1,500 TJ), it incorporates guidance features of the B61-12 for better accuracy while being more powerful than that version to strike harder and large-area targets.[5]

Design

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The bomb is 12 feet (3.7 m) long, with a diameter of 18 inches (460 mm). The actual nuclear explosive package, judging from published drawings, occupies some 3 to 4 ft (0.91 to 1.22 m) in the forward part of the bomb case. The bomb weighs approximately 2,400 pounds (1,100 kg). The location of the lifting lugs shows that the greater part of the total mass is contained in the nuclear explosive.

The bomb has a variable yield: the destructive power is adjustable from somewhere in the low kiloton range up to a maximum of 1.2 megatonnes of TNT (5.0 PJ), some 80 times the explosive power of the bomb dropped on Hiroshima. The weapon is protected by a Category "D" Permissive Action Link (PAL) that prevents the enabling or detonation of the weapon without proper authorization.[6][7]

About 650 B83s were built, and the weapon remains in service as part of the United States "Enduring Stockpile".[2]

Aircraft capable of carrying the B83

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The following aircraft are certified for carrying the B83 bomb:

Nuclear capability has been removed from the B-1B, mostly attributed to START I & START II,[10][11] and the B-52 no longer carries gravity nuclear bombs.[9]

Novel uses

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The B83 is one of the weapons considered for use in the "Nuclear Bunker Buster" project, which for a time was known as the Robust Nuclear Earth Penetrator, or RNEP. 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.

The physics package contained within the B83 has been studied for use in asteroid impact avoidance strategies against any seriously threatening near earth asteroids. Six such warheads, configured for the maximum 1.2 megatonnes of TNT (5.0 PJ), would be deployed by maneuvering space vehicles to "knock" an asteroid off course, should it pose a risk to the Earth.[12]

See also

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References

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  1. ^ Blaney, Betsy (26 October 2011). "End of an Era: Last of Big Atomic Bombs dismantled". San Francisco Chronicle. Archived from the original on 28 October 2011. Retrieved 27 October 2011.
  2. ^ a b c d e f Sublette, Carey (11 November 1997). "Nuclear Weapons Archive - B83". Archived from the original on 4 February 2006. Retrieved 23 December 2013.
  3. ^ Biggest US nuclear bomb dismantled in Texas Archived 18 November 2018 at the Wayback Machine. The Guardian. 25 October 2011.
  4. ^ "Biden to scrap Trump missile project but critics attack US 'nuclear overkill'". the Guardian. 27 October 2022.
  5. ^ US to build new nuclear gravity bomb. Defense News. 27 October 2023.
  6. ^ Energy and Water Development Appropriations for Fiscal Year 1980: Hearings Before a Subcommittee of the Committee on Appropriations, United States Senate. U.S. Government Printing Office. 1979. Archived from the original on 8 May 2021. Retrieved 10 February 2021.
  7. ^ President, United States (1981). Fiscal Year 1982 Arms Control Impact Statements: Statements Submitted to the Congress by the President Pursuant to Section 36 of the Arms Control and Disarmament Act. U.S. Government Printing Office. Archived from the original on 8 May 2021. Retrieved 10 February 2021.
  8. ^ T.O. 1B-52H-1
  9. ^ a b Kristensen, Hans M.; Korda, Matt (2019). "United States nuclear forces, 2019". Bulletin of the Atomic Scientists. 75 (3): 122–134. Bibcode:2019BuAtS..75c.122K. doi:10.1080/00963402.2019.1606503.
  10. ^ Pawlyk, Oriana (12 July 2017). "START Lanced the B-1's Nukes, But the Bomber Will Still Get New Bombs". Military.com. Military Advantage. Archived from the original on 26 September 2017. Retrieved 25 September 2017.
  11. ^ "B-1B Lancer". U.S. Air Force. Retrieved 30 July 2024.
  12. ^ Coppinger, Rob (8 March 2007), NASA plans 'Armageddon' spacecraft to blast asteroid, archived from the original on 5 September 2011, retrieved 26 February 2021 (article at Flightglobal.com)
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