F A Pieper; M V Barton; R W Sauer; TRW SPACE TECHNOLOGY LABS REDONDO BEACH CA.
A total of 16 reed gages of a design which had previously been used in Operations Plumbob, Hard tack, Hardtack II, and Nougat were installed in the Small Boy Event. These gages recorded hori zontal and vertical displacement shock spectra at four stations between 185 feet and 290 feet of ground zero. Some gages were placed at the sur face and others at 10-foot depth. All gages yielded readable records and data is presented in both tabulated and chart form. The gages 10 feet below the surface showed a marked attenuation at high frequencies but very little attenuation of horizontal shock at frequencies below 50 cps and of vertical shock at frequencies below 25 cps. A peak was noted in horizontal acceleration be tween 90 and 150 cps at the surface and between 50 and 90 cycles at 10-foot depth. No similar peaks were noted in the vertical acceleration. Examination of the data presented indicated that no simple scaling was possible for the ground shock which occurred. This data will have to be studied with other shock spectra data so that it may be properly weighed, and quantitative scaling rules derived. (Author).