- Author
-
Office of Civil Defense
- Title
- Fire Aspects of Civil Defense.
- Coporate
- Office of Civil Defense, Washington, DC
- Report
-
TR-25,
July 1968,
12 p.
- Keywords
-
civil defense
|
thermal ignition
|
fire growth
|
climate
|
weather effects
|
aerial explosions
|
mass fires
|
life safety
- Identifiers
- ignition thresholds; atmospheric attenuation; fire effects of air blast; fire countermeasures
- Abstract
- This report describes the general dimensions of the fire threat resulting from nuclear attack, particularly as a result of ignition of thin materials by the thermal (heat) flash. A review of the best available information on the thermal ignition capabilities of air-burst nuclear weapons with yields from 1 megaton to 100 megatons indicates that thermal ignitions may occur, under average to good visibility conditons, at ranges where the blast overpressure is between 1 and 3 pounds per square inch (p.s.i.), with perhaps 2 p.s.i. as a reasonable estimator of the region within which ignitions may occur. The severity of resulting fires and the likelihood of fire spread depend on the amount and spacing of combustibles within the ignition area. Mass fires are likely only in built-up urban areas rather than in suburban or rural areas. Thus the potential ignition areas cannot be considered as a single fire area "engulfed in flame" sine the controlling factors are the occurrence and size of the combustible areas rather than the ignition range of the weapon.