South African gun-type bomb (Hobo/Cabot)

Hobo / Cabot

Aircraft bombSouth AfricaGun-type fission

No freely licensed photo of this device yet.

Yield · TNT equivalent6 kt

Key specs

Country: South Africa
Design: Gun-type fission
Type: Aircraft bomb
In service: 1982–1989
Number built: 6

Overview

South Africa secretly built six gun-type uranium bombs in the 1980s as a deterrent; the first, Hobo (later Cabot), was completed in 1982 with a reported yield of about 6 kt. All six, and a seventh unfinished one, were dismantled in 1989–91, the only case of a country giving up nuclear weapons it had built itself.

Effect radii: estimates

Calculated for 6 kt

Fireball, maximum radius: ≈ 120 m
Initial radiation, 500 rem (5 Sv): ≈ 1.2 km
Blast 5 psi: most buildings collapse: ≈ 1.3 km
Thermal: third-degree burns: ≈ 1.4 km
Blast 1 psi: windows shatter: ≈ 4 km

Estimated ground ranges for an air burst at the optimum height over flat, open ground, computed from the yield with standard scaling laws. These are not measurements: real effects depend on the height of burst, terrain, buildings and weather.

Formulas from: Glasstone & Dolan, The Effects of Nuclear Weapons (1977), chapter II; Carey Sublette, Nuclear Weapons FAQ, section 5

Sources

South Africa and weapons of mass destruction, Wikipedia