B61 (nuclear weapon)

From Citizendium, the Citizens' Compendium

The U.S. B61 nuclear weapon is a gravity bomb of low to medium yield, from as low as 300 tons and as high as 340 KT. ^[1] Its physical weight has been described as in the 700-800 pound range; the bomb is 142 inches long and 13.4 inches and diameter It can be delivered by every U.S. aircraft certified to drop nuclear weapons, from the F-16 Fighting Falcon to the B-2 Spirit, and, under "dual key" arrangements, by aircraft of Belgium, Germany, Greece, the Netherlands, and Turkey.^[2]

The yield can be changed in flight.^[2] The bomb has a wide variety of high and low altitude fuzing modes, from high to low airburst, surface burst, and in one variant, subsurface burst. It is the only U.S. weapon that is considered "tactical" although it can be delivered on by "strategic" aircraft.

Contents 1 Physics package 2 Safeguards and surety 3 Variants 4 References

Physics package

The B61 has an enriched uranium, boosted fission Primary.^[2]

Safeguards and surety

The later models had Category D and F permissive action links; it can reasonably be assumed all are at Category F.

Variants

One version, the B61-11, has a limited earth-penetrating capability, for use against hardened underground structures. It will penetrate about 20 feet into earth, which causes more efficient transfer of blast energy to ground shock. ^[3] The -11 will generate fallout, but by being even slightly underground when it detonates, a lower yield might be adequate than a higher-yield surface burst. The U.S. assumes, however, that the greater efficiency of the B61-11 will allow it to replace the 9MT B53 bomb.

In no way, however, should it be assumed the B61-11 penetrates deeply enough to contain its fallout. Were it used in an urban area, there would be very substantial radiation casualties; it is unlikely that any air-launched weapon could withstand the impact of penetrating deeply enough to contain even a small explosion. ^[3]

References