Test on the Loading of Horizontal Cylindrical Shapes; Operation Upshot-Knothole, Nevada Proving Grounds March-June 1953 Project 3.3 Report to the Test Director WADC-TN-55-420

114 pages [stated]. Red lettering on edge. Illustrations. Tables. Introduction. General Description of Test. Pretest Considerations. Experimental Results. Discussion of Results. Pressure Measurements. Strain Measurements. Conclusions and Recommendations. Appendix. Bibliography. Declassified to UNCLASSIFIED. Originally classified as SECRET RESTRICTED DATA. This report deals with the pre- and post-test work on the Air Force Structures Test, Project 3.3 of Operation UPSHOT-KNOTHOLE, Tests on the loading of Horizontal Cylindrical Shapes. The general objective of this test was to increase the knowledge of blast loadings on structures of cylindrical shape. The specific objectives were to determine the effect o (1) shock strength, (2) size (i.e. scaling), (3) ground proximity, and (4) three-dimensionality. Five horizontal cylinders of various size and distance above ground were situated in the mach region of both Shots 9 and 10. Instrumentation consisted of pressure gages and strain gages, the latter representing the output of a net force measurement system. The pressure-time distribution was obtained on a cylinder one radius above the ground. The results indicate the build up and clearing times to be essentially the same as for a cylinder in free space, except for a somewhat longer clearing time on the front face. Operation Upshot-Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site. It followed Operation Ivy and preceded Operation Castle. The test series was notable as containing the first time an AFAP shell was fired (GRABLE Shot), the first two shots (both fizzles) by University of California Radiation Laboratory—Livermore (now Lawrence Livermore National Laboratory), and for testing out some of the thermonuclear components that would be used for the massive thermonuclear series of Operation Castle. One primary device (RACER) was tested in thermonuclear system mockup assemblies of TX-14, TX-16, and TX-17/TX-24, to examine and evaluate the behavior of radiation cases and the compression of the secondary geometries by the primary's x-rays prior to full-scale testing during Castle. Following RACER's dodgy performance, the COBRA primary was used in the emergency capability. …