ee 189 * PEcs) Projeo* 1.1 - Basic Blast Measurements ~ J. J, Messsros OBJECTIVE ayy) The objective of Project 1.1 during BM (1000) was to observe the aifferencea in propagation of the precursor shock over a vegetated surface and a clear surface. TESTRON Five identical gage stations vere placed op each surface at distances ranging frow 900 feet to 1600 feet from ground sero. Each station co- sisted of one self-recording "Q" gage and two self-recorcing pressure-tine gages. Alsc, ten experinental rediation-initiated gages vere placed at various stations. BESULIS . Due to the unexpected high yield of the shot, many of the gages failed to give significant records. In all the gages the pressure-sensitive oap- wules had been subjected to pressures setinated at 200 to 300 percent above their rated values, In addition, the high pressures displaced several *Q* gage nounte and caused considerable chipping of the glass record discs. Only one of the radiation-initiated gages pave a pressure-tise record. A pressure-distance plot of the overpressure values obtained by the pt gegee ie showm in Figure 1.1-1. There appears to be no significant difference in the overpressures of the vegetated surface and the clear surface. BEST AVAILABLE COPY 13 ge