The New DDESB Blast Effects Computer

Abstract : In 1978, the Department of Defense Explosives Safety Board (DDESB) released a circular slide rule called the "Blast Effects Computer (BEC)." This slide rule was designed to solve problems and provide data related to the expected damage to various possible targets due to blast effects resulting from an explosion of ammunition or explosives stored above ground or in earth-covered magazines. In the 20 years that have elapsed since the slide rule was designed, the state of the art in predicting both blast effects and damage has progressed significantly. However, the need for a prediction tool has not disappeared in the intervening years; if anything, this need has increased. As a result, the DDESB has prepared an update to the circular slide rule. This update is in the form of an EXCEL spreadsheet template that will run on any computer upon which EXCEL Version 5.0 (or later) is installed. Version 1.0 of the new blast effects computer (BECV1) was a simple computerization of the circular slide rule with an update to the Kingery airblast pressure-distance model and other minor corrections to the algorithms. This version was released in November 1997. Version 2.0 is now available. Incorporated into this version are updated airblast information for earth-covered magazines and hardened aircraft shelters. Also included are updated airblast algorithms for MK 82, MK 83, MK 84 and M117 bombs, as well as M107 155-mm projectiles. This paper describes BECV2, discusses some of the new algorithms that are used, and demonstrates the computer's use through illustrative examples.