ABSTRACT The general objective was to obtain data sufficient to characterize the fallout, interpret the aerial and oceanographic survey results, and check fallout-model theory for Shots Cherokee, Zuni, Flathead, Navajo, and Tewa during Operation Redwing. Detailed measurements of fallout buildup were planned. Measurements of the radiation characteristics and physical, chemical, and radiochemical properties of individual solid and slurry particles and total cloud and fallout samples were also planned, along with determinations of the surface densities of activity and environmental componentsin the fallout at each major station. Standardized instruments and instrument arrays were used at a variety of stations which included three ships, two barges, three rafts, thirteen to seventeen deep-anchored skiffs, and four islands at Bikini Atoll. Total and incremental fallout collectors and gamma time-intensity recorders were featured in the field instrumentation. Special laboratory facilities for earlytime studies were established aboard one ship. A number of buried trays with related survey markers were located in a cleared area at one of the island stations. Instrument failures were few, and a large amount of data was obtained. This report summarizes the times and rates of arrival, times of peak and cessation, mass- arrival rates, particle-size variation with time, ocean-penetration rates, solid- and slurryparticle characteristics, activity and fraction of device deposited per unit area, surface densities of chemical components, radionuclide compositions with corrections for fractionation and induced activities, and photon and air-ionization decay rates. A numberof pertinent correla- tions are also presented: predicted and observed fallout patterns are compared, sampling bias is analyzed, gross-product decay is discussed in relation to the t™'-* rule, fraction-of-device calculations based on chemical and radiochemical analyses are given, the relationship of filmdosimeter dose to gamma time-intensity integral is considered, a comparison is made between. effects computed from radiochemistry and gamma spectrometry, air-sampling measurements are interpreted, and the fallout effects are studied in relation to variations in the ratio of fission yield to total yield. Some of the more-important general conclusions are summarized below: The air burst of Shot Cherokee produced no fallout of military significance. Fallout-pattern locations and times of arrival were adequately predicted by model theory. Activity-arrival-rate curves for water-surface and land-surface shots were similar, and were well correlated in time with local-field ionization rates. Particle-size distributions from land-surface shots varied continuously with time at each Station, with the concentration and average size appearing to peak near time-of-peak radiation rate; the diameters of barge-shot fallout droplets, on the other hand, remained remarkably constant in diameter at the ship stations. Gross physical and chemical characteristics of the solid fallout particles proved much the Same as those for Shot Mike during Operation Ivy and Shot Bravo during Operation Castle. New information was obtained, however, relating the radiochemical and physicat characteristics of individual particles. Activity was found to vary roughly as the square of the diameter for irregwar particles, and as some power greater than the cube of the diameter for spheroidal particles. Fallout from barge shots consisted of slurry droplets, which were composed of water, sea salts, and radioactive solid particles. The latter were spherical, generally less than i micron in diameter, and consisted mainly of oxides of calcium and iron. At the ship locations, the solid particles contained most of the activity associated with the slurry droplets; close in, however, most of the activity was in soluble form. Bulk rate of penetration of fallout in the ocean was, under several restrictions, similar for both solid and slurry particles. Estimates are given of the amountof activity which may have 5