Chapter 2 SUMMARY OF EXPERIMENTAL PROGRAMS 2.1 TASK UNIT 3, DOD PROGRAMS Program 1, Blast and Shock Measurements The thirteen projects of Program 1 investigated blast and shock parameters and effects produced by two underwater shots, two surface shots, and ~ the VHA shot. The general objective was to define the environments pro~ duced by blast waves from nuclear detonations, both to increase our understanding of basic phenomena, and to support projects measuring effects produced by blast waves. Areas of particular interest were underwater and air blast pressures produced by shots Wahoo and Umbrella, underground shock phenomena produced by shots Koa and Cactus, and blast wave characteristics (including en- ergy partition) of shot Yucca. Ground Shock The entire DOD effort on study of ground shock phenomena was concentrated on two surface shots, Cactus and Koa. Complete air blast lines were installed on these shots also so that the air blast input contributing to underground effects would be known. Shot Cactus was chosen to provide a low yield tie-in of underground data with similar data obtained on Operation Plumbbob at NTS. Shot Koa was instrumented so that comparisons (Cactus vs Koa) could be made between data from low and high yield shots under similar soil conditions. All five projects participating on shots Cactus and Koa successfully obtained the larger part of desired data. Results of individual projects are summarized below. Air Blast. Complete air blast data were obtained on both shots. Dynamic pressure data at 3-ft heights require further data reduction before results can be reported. Maximum overpressures from both shots when scaled to 1 kt at standard sea level conditions agreed well with a 1.6-kt 23 AFWL/HC ae