A 1000-lb sphere of high explosive detonated 25 feet above the ground, in Alberta, Canada, in 1987. A
cable support tower is silhouetted against the fireball. The structures on the right are camera bunkers.
DEWEY McMILLIN & ASSOCIATES LTD created the black and white smoke trails on the left to visualize the air motion in the blast wave. At the time of the picture the seven trails closest to the explosion have been hit by the blast wave and are are moving away from the fireball. The chair-like steps seen in the bottom of three of them are caused by the difference in flow speed across the contact surface separating the primary and Mach stem blast waves. The poles seen against the sky support electronic pressure transducers. Measured pressure-time histories were used as check points in the numerical reconstruction of the primary and Mach stem blast waves.
DM&A specialize in making blast measurements, analyzing and reconstructing blast wave data, and making the results available using friendly expert software.
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