The Effects of Nuclear Weapons · 3rd edition, 1977 · public domain
Nuclear Bomb Blast Radius, with the printed page behind every number
The table gives the distance from ground zero to four effects, at three yields. None of it is model output: the blast radii are read off Fig. 3.73c at 1 kt and then scaled by the manual's own cube-root law (Eq. 3.61.2, p. 101); the thermal radii are read directly off Fig. 7.42 (p. 291) and are not scaled at all. Every cell carries the figure and printed page it came from, so any single number can be checked against the book in under a minute.
For one city at a time instead of three yields in a row, the nuke simulator shows the rings around a chosen city; the nuclear bomb map lays the same five rings over real ground, north-up.
Air burst — the default reading
Height of burst is not chosen here. Each contour is read at its own peak — the point where it reaches furthest from ground zero — so every overpressure carries the burst height that the chart itself associates with that maximum. The manual works its own example the same way on p. 114.
Scroll the table sideways →
| Effect | 15 kt | 100 kt | 1,000 kt |
|---|---|---|---|
| Fireball breakaway radius · Eq. (2.127.1) | 0.10kmprinted equation · no burst height inputEq. (2.127.1) · p. 70printed equation, not a chart reading | 0.21kmprinted equation · no burst height inputEq. (2.127.1) · p. 70printed equation, not a chart reading | 0.53kmprinted equation · no burst height inputEq. (2.127.1) · p. 70printed equation, not a chart reading |
| 5 psi overpressure peak of the 4 and 6 psi contours, interpolated | 1.71kmburst height 2,509 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 2,275 ft (1 kt) | 3.22kmburst height 4,723 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 2,275 ft (1 kt) | 6.93kmburst height 10,174 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 2,275 ft (1 kt) burst height 10,174 ft is beyond the manual's 5,000 ft homogeneous-atmosphere assumption |
| 1 psi overpressure peak of the outermost contour | 5.28kmburst height 3,884 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) | 9.93kmburst height 7,311 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) burst height 7,311 ft is beyond the manual's 5,000 ft homogeneous-atmosphere assumption | 21.40kmburst height 15,750 ftCh. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) burst height 15,750 ft is beyond the manual's 5,000 ft homogeneous-atmosphere assumption |
| Thermal · 2nd-degree 4.5 cal/cm² · light skin, unshaded | 3.37kmburst height 591 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled4.5 cal/cm² · light skin, unshaded | 6.99kmburst height 1,262 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled4.5 cal/cm² · light skin, unshaded | 16.68kmburst height 3,170 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled4.5 cal/cm² · light skin, unshaded |
| Thermal · 3rd-degree 10 cal/cm² · light skin, unshaded | 1.77kmburst height 591 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled10 cal/cm² · light skin, unshaded | 4.02kmburst height 1,262 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled10 cal/cm² · light skin, unshaded | 10.35kmburst height 3,170 ft · 200·W^0.4 (§7.42)Ch. 7 · Fig. 7.42 · p. 291read directly off Fig. 7.42, not scaled10 cal/cm² · light skin, unshaded |
Why three cells carry an amber warning. Reading at the peak of each isobar puts the 1 Mt burst heights at 10,174 ft (5 psi) and 15,750 ft (1 psi); even the 100 kt 1 psi row lands at 7,311 ft. Fig. 3.73c is computed for a homogeneous sea-level atmosphere at burst heights of 5,000 ft or less (§3.73, p. 110), so these cells extrapolate that assumption by up to a factor of three. The numbers are still the manual's curve multiplied by the manual's scaling law, but they should be read as the edge of what this chart supports rather than as precise distances. No altitude correction from §3.64–3.66 is applied here, and leaving it out pushes these figures low rather than high.
How to read the tags under each number. scaled from the 1 kt curve (§3.61, p.101) means the figure is the 1 kt reading
multiplied by W1/3 — the manual's own scaling law, applied once at build time, not
recomputed in your browser. interpolated between 4 and 6 psi contours means the
contour does not exist on the chart at all: Fig. 3.73c prints 1, 2, 4, 6, 8 and 10 psi
only, so 5 psi is placed between the 4 and 6 psi curves at the logarithmic pressure position
0.5503. read directly off Fig. 7.42 means no scaling was used. A star (*) marks a
value that has not been individually spot-checked; the verification section of the audit trail
lists which ones.
Contact surface burst
Height of burst is zero: each distance is read where the contour meets the bottom edge of Fig. 3.73c, which is the convention the manual states on p. 106. A contact burst puts the fireball at the surface, so the fireball column switches to Eq. (2.127.2) on p. 71 — the two fireball coefficients are never mixed.
Scroll the table sideways →
| Effect | 15 kt | 100 kt | 1,000 kt |
|---|---|---|---|
| Fireball contact burst · Eq. (2.127.2) | 0.13km * contact burst · height of burst = 0Eq. (2.127.2) · p. 71printed equation, not a chart reading | 0.28km * contact burst · height of burst = 0Eq. (2.127.2) · p. 71printed equation, not a chart reading | 0.70km * contact burst · height of burst = 0Eq. (2.127.2) · p. 71printed equation, not a chart reading |
| 5 psi overpressure bottom edge of Fig. 3.73c, height of burst = 0 | 1.02km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 1,361 ft (1 kt) | 1.93km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 1,361 ft (1 kt) | 4.15km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) interpolated between 4 and 6 psi contours, at 1,361 ft (1 kt) |
| 1 psi overpressure bottom edge of Fig. 3.73c, height of burst = 0 | 2.88km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) | 5.42km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) | 11.67km * contact burst · height of burst = 0Ch. 3 · Fig. 3.73c · p. 115scaled from the 1 kt curve (§3.61, p.101) |
The thermal rows are deliberately absent from this table. Fig. 7.42 is drawn for air bursts at burst heights of 200·W0.4 ft, and the manual treats thermal radiation from a surface burst by a separate route (§7.41, p. 290). Rather than blend two procedures into one column and call the result a number, this page reports blast and fireball only for contact bursts. Nothing is missing by accident.
What each ring is
Fireball
The incandescent sphere itself. The value is the breakaway radius — the radius at the moment the shock front separates from the fireball. For air bursts it comes from Eq. (2.127.1) on p. 70; for contact bursts, Eq. (2.127.2) on p. 71. §2.129 notes that the fireball may grow to about twice this radius, which is why the figure is described as a breakaway value rather than a maximum.
5 psi overpressure
Peak overpressure on the ground, not the incident pressure in free air. Fig. 3.73c plots that quantity, so the reflected wave is already inside the number. There is no 5 psi contour printed on the chart; this row is interpolated between the 4 and 6 psi curves at a fixed logarithmic position, and every 5 psi cell says so.
1 psi overpressure
The outermost contour drawn on Fig. 3.73c, and the one most sensitive to burst height: at 1 kt it reaches 7,020 ft at a burst height of 1,575 ft, against 3,830 ft for a contact burst. That sensitivity is why this page reads the peak of the curve instead of picking a height of burst in advance.
Thermal · second and third degree
Slant range to a given irradiance, read off a chart drawn for unshaded light skin with 12-mile visibility. 4.5 cal/cm² is the lower edge of the band the manual ties to second-degree burns (§12.65, p. 563); 10 cal/cm² is the column reported for third-degree burns (Fig. 12.64, p. 564). Clothing, shelter, haze and skin tone all move this figure, and the page makes no adjustment for any of them.
Cross-checks against the manual's own prose
Four places where the book states a number in words. If a reading were wrong, these are the places it would show up first.
Scroll the table sideways →
| Check | What the manual says | This table | Difference |
|---|---|---|---|
| 1 Mt, 4.5 cal/cm² slant range G1 | 9–10 mi band, outer edge (§12.66, p.563) | 10.36 mi | +3.6% |
| 1 Mt, 6 cal/cm² slant range G2 | 9–10 mi band, inner edge (§12.66, p.563) | 8.65 mi | -3.9% |
| 1 Mt, 8 cal/cm² slant range G3 | about 7 mi (§7.43, p.290) | 7.35 mi | +5.0% |
| 1 kt, 4 psi maximum ground distance G4 | 2,600 ft at about 1,100 ft HOB (p.114 worked example) | 2,618 ft | +0.7% |
What this table is not
It is a set of distances from ground zero, and nothing more. It does not estimate deaths, injuries, building damage at a specific address, fallout, or what would happen in any actual event. It also does not cover underwater, underground or high-altitude bursts, multiple warheads, or terrain shielding. The audit trail — where these numbers come from — lists what is left out and why, including how the two thermal thresholds were placed and where the 1 Mt rows leave the chart's assumptions behind.
To reproduce any value: open the cited figure at the cited printed page, read the distance at
the stated burst height, multiply by W1/3 where the cell says
scaled, and convert feet to metres with 0.3048. The same numbers, with the pixel
coordinates they were read at, ship in
src/data/effects.json and data-ledger.csv.