B53

Aircraft bombUnited StatesThermonuclear (staged)

B53 — Photo: brewbooks from near Seattle, USA · CC BY-SA 2.0 · background removed · partly completed with AI

Yield · TNT equivalent9 Mt

Key specs

Country: United States
Design: Thermonuclear (staged)
Type: Aircraft bomb
Weight: 4.01 t
Length: 3.76 m
Diameter: 1.27 m
In service: 1962–1997
Number built: 340

Overview

A 9 Mt thermonuclear gravity bomb for the B-47, B-52 and B-58 bombers, also used as the W53 warhead of the Titan II missile. For decades it was the most powerful weapon in the US stockpile; it was meant for deeply buried targets, using a surface burst to send a shock wave through the ground.

About 340 were built from 1962 to 1965. Its design goes back to the TX-46 device tested as Hardtack Oak in 1958. Most were retired in 1997, and the last one was dismantled at the Pantex Plant in October 2011.

Effect radii: estimates

Calculated for 9 Mt

Fireball, maximum radius: ≈ 2.3 km
Initial radiation, 500 rem (5 Sv): ≈ 4.7 km
Blast 5 psi: most buildings collapse: ≈ 15 km
Thermal: third-degree burns: ≈ 28 km
Blast 1 psi: windows shatter: ≈ 46 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

Tests and use

Date	Event	Site	Yield
Jun 28, 1958	Hardtack I OakTest of the TX-46 device from which the B53 was developed.	Enewetak Atoll, Marshall Islands	8.9 Mt

Test footage

Archive films hosted on YouTube. Nothing loads from YouTube until you press play; the player then comes from youtube-nocookie.com.

AtomicHeritage · youtube.com

Sources

Complete List of All U.S. Nuclear Weapons, Nuclear Weapon Archive (Carey Sublette)
B53 nuclear bomb, Wikipedia