WE.177

Aircraft bombUnited KingdomThermonuclear (staged)

No freely licensed photo of this device yet.

Yield · TNT equivalent0.5–450 kt

Key specs

Country: United Kingdom
Design: Thermonuclear (staged)
Type: Aircraft bomb
Weight: 457 kg
Length: 3.38 m
Diameter: 406 mm
In service: 1966–1998
Number built: 319

Overview

Britain’s last free-fall nuclear bomb family, in service from 1966 to 1998 with the RAF and the Royal Navy. The WE.177A (0.5 or 10 kt, 272 kg) also served as a nuclear depth charge; the thermonuclear B and C versions gave 450 and 200 kt.

Effect radii: estimates

Calculated for 450 kt

Fireball, maximum radius: ≈ 700 m
Initial radiation, 500 rem (5 Sv): ≈ 2.7 km
Blast 5 psi: most buildings collapse: ≈ 5.4 km
Thermal: third-degree burns: ≈ 8.2 km
Blast 1 psi: windows shatter: ≈ 17 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

WE.177, Wikipedia