This Cold War Damage Prediction calculator [VN 1] was commissioned by the Defense Nuclear Agency and designed by Horizons Technology Inc. of San Diego in 1982. The 8″ diameter rule is made of plastic and was produced by Perrygraf.
The purpose of the rule was to allow planners to calculate the probability of destroying an enemy point or area target by attacking it with a nuclear weapon.
The rule has the same purpose as the Damage Probability Computer produced by RAND [see this post]. The DNA rule is more sophisticated and has the following additional features.
1. It can be used for attacks on area targets [towns and cities] and not just point targets.
2. It allows aim point offset.
3. It allows conversion from feet to meters [useful when used in a NATO context because at the time some NATO members were using the metric system and some imperial units].
The rule’s documentation makes clear that calculations are made using the Vulnerability Number system [see this post]. The blue side of the rule was used for targets assigned a P vulnerability number and the green side for those with a QVN.
When used in planning attacks on a area target the RT is the target radius which includes 95% of the target elements. HOB is height of burst.
A nine page users guide was issued with the rule. A revised version of this rule was issued in 1986. This will be the subject of a later post.