was mounted on the barge to obtain information relative to the effect of slope (pitch) on the retentivity of contamination. These panels were arranged in 10 degree increments of slope ranging from horizontal to vertical as shown in Fig. 2.2. The barge participation was originally contemplated for Shot Echo, and the barge was moored in a favorable downwind location with respect to ground zero selected for this shot. In view of the cancellation of this shot, however, the barge was moved to as favorable an anchorage as possible for participation in Shot 6. Besides the data expected to be derived from the panels themselves, additional operational decontamination infermation was expectzd to be obtained from the clean-up of the barge itself. 2.2 2.2eL OCR IPTION OF TEST SURFACES AND EQUIPMENT — Test Panels Four identical sets of: test panels were fabricated. Each set cousisted of ik, four foot square panels of widely used outside construction material surfaces. Table 2.1 contains a description of the type cf surfaces, preprotection measure, and mounting position of each uf the panels. The relatively heavy masonry and concrete pavement panels were fabricated in two sections to facilitate handling, but their mounting was in pairs for proper comparison purposes. Figures A.l through A.1k show a view of each panel. These photographs were taken subsequent to decontamination and on some surfaces clearly show the effects of weathering and decontamination efferts. 2.2.2 Panel Mounting Racks To expedite handling, and thereby to reduce the exposure of recovery personnel to a minimum, each set of panels was mounted on a lightweight tubular steel rack designed to fit a predetermined space on board ship. The test panels were mounted in such manner as to retain their normal orientation under fallout exposure conditions, - i.e., pavement panels were placed horizontally, wall panels vertically, and roofing panels on slopes consistent with their normal use, Each rack was equipped with a lifting ring and a quick unfastening device to facilitate recovery under contaminated conditions, This assembly was handled as a single unit from shore to ship initially, and from ship to shore following contamination, 2.2.3 Panel Weather Covers It was anticipated that several days would elapse following exposure to contamination before the panels could be recovered from the ships. To preserve the original contamination patcerns on the panels of the YAG 0 (unprotected ship) from the effects of weather during this period, delayed action, flexible, waterproof covers were provided, These covers, similar in operation and general appearance to conventional window shades, were rolled up and suspended above the panels. Metal guides were provided along the edges of each panel, 17 CONFIDENTIAL — RESTRICTED DATA

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