Operation Redwing, a Preliminary Report of () (Cherokee) (Deleted)

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Fig. 0-1- BikiniAtoll North Reef Scientific Stations, Part I. . 9 Fig. O-2- Bikini Atoll North Reef Scientific Stations, Part II.. 10 Free Air Pressure Measurements at Altitudes . . . u 17 Drag Characteristics of Various Shapes. ...lc 19 Decontamination and Protection. ......... Neutron Flux Measurements and Shielding Studies.. Neutron Induced Soil Radioactivity. ....,4l Rooket Determination of the Actitity Distributim Within the Stabilized Cloud .........lc Fallout Studies by Oceanography Methods ....l Collection and Characterization of Fallout with Ana~SiS of Falluut and of Base Surge .....l

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Sources to the Ship of the Various Radiation Standard Recovexy Procedure for Tactical Verification of Washdown Effectiamnes8 as a Difference in Effect of Short and Lmg Duration Biomedical Effects - Flash Blindness and Thexmal Flux and Albedo Measurements from Accurate Location of Electromagnetic Pulse Effects of Atomic Explosion on the Ionosphere . l Determination of Characteristics of Airborne Flush Mounted Jmtennas and Photo Tubes for Yield Analysis of Electromagnetic Rxlse Produced by Basic Thermal Radiation Measurements. ......

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Thermal Effects on the Strexwth of Aircraft Structural Sandwich Type Airborne High Resolution The of Arrival. .... Measurement of Alpha and Chord Spectrosco~ and Time Interval in Selected

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This is a preliminary reports and therefore does not give either ccqle~ or final results of the work of the various projects. No fio~tion on the conetmction of the derice is included in order that the chasfli-tlon W ~ kept to Secret Restricted Data. detonated at 0.550:38.7. The &get w near the center of ?kmu IsM on m position was approxlm~tely 20)OC0 feet northeast of the target and act~ height of burst was approximately l.L!&Ofeet.

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Observed Weather at Shot Time Fig. O-1 - Bikini Atoll North Reef Scientific Stations, Fig. O-2 - & Atoll North Reef Scientflic Stations,

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Visibility More than 10 miles CUJUDS: 2/10 Cumdus? bases 1800 ft, tops 250’0ft; 2/10 cirrus W.ATHI?R: Very widely scattered showers. There were three showers in the vicinity of the atoll at to the south of Eninman (Tare); shOt time: one very light shower just one light shower, which was dissipating s~44’yoF SI?A: Bikini Lagoon: Average of highest 1/3 of waves; 3.0 ft. at anchorage, 2.5 ft. near ?lamu. The predominant direction of 0 open Sea: Average of waves at anchorage was 135°; near NSJINI,1~ l open sea was 100 .

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Blast and Shock Measurements Nuclear Radiation and Effects Stmxtures and Equipnent Tests of Service J3quipnentand The-l Radiation and Effects

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The primary objective of Project 1.1 was to measure and record the blast pressure at various distances from a high field air burst in the megaton range. Secondary objectives were the measuring of dynamic pressure vs time at the same ground distances with the exception of the station located at the intended GZ point. Also Project 1.1 was requested to make measurements of the diffraction of the shock wave over the man-made islands and around the Project 3.1 structures. pressure gages were the basic instrumentation used for measuring air blast pressures. The gage is activated from the flash of the detonation. A back-up method for triggering the gage is a thermal link that disengages when heat is applid. The gage use~ to measure dynamic pressure is also a self recording gage designed at BRL and referred to as a ‘qflgage. A total of 11 contractor installed stations were instrumented with one 3 foot ‘qn gage and three pressure-time gages. The project installed sixteen stations which included 14 pressure-time gages and three 10 foot “q” gages. gages and 14 ‘qn gages were installed for out Of a total of 47 pess~e-tfie gages 9 recorded peak

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pressure only. This was because of a failure in the photo initiation circuit or the thermal link causing the before shot time. A total of three ‘qR gages out of U also ran gage to start time from the same reasons mentioned in the pretious paragraph. Of the 38 pressure-time gage records 6 are considered not reliable for plotting pressure vs distance curves because of the small amplitude of the records, extreme oscillations or a slow rise time caused by the clogging of the pressure inlet hole. The ‘qn gage records are almost a complete loss because the orientation of the detonation caused the shock wave to strike the Tgages at odd angles, some from the rear, some from broadside and ‘~ some from the front at large angles. No explanation is offered at present for the variation the pressure along the reef stations from those measured on land stations. Whether this is a true phenomenon or a function of the gage mount will have to be determined at a later date.

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To measure free air peak shock overpressure as a function of distance in a horizontal tically above the burst. To determine the blast To study the effect of To study the effect of direction at burst height and verthe nonhomogeneous atmosphere on the surface and heating of the air near the surface on shock transmission. The instrumentation for this shot was smoke rocket photography. The rockets, both Deacon and 5.O”j were fired from two stations” One was on the south enq of Bokobyaa3aa (Able) and the other was on the reef 12,000t SW of Bokobyaadaa (Able). The cameras were located The rocket instrumentation and the cameras functioned properly but as a result of the bombing error the films obtained for the project are probably of no value. AU other films obtaine~ by EG!X that might be of use to the project were inspected. Four films were found that may be of limited value. Through two of these films a limited amount of pressure distance data at burst height may be obtained. The other two films may be of some value for a study of surface effects~

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The objective of Project 1.4 was to obtain basic free air Peak overpressure measurements vertically above an air burst megaton weapon. Information was sought covering the range of 20 psi to 1 psi. This data was needed to further the study of the effect of altitude on the propagation of the shock wave so that safe ranges for delivery aircraft could be specified more accurately. were deployed in a vertical array above intended ground zero. The rang~ of altitudes at burst time nas 93o feet to 33~@ feeto The large horizontal bombing error precluded the canisters being in the range of All twelve canisters telemetered useful data. Ten of the twelve two were in the math reflection region below the triple point path. The assumption*’~~, ~ gives optimum agreement between measured and computed peak overpressures, and with this assumption the r.m.s. percentage deviation between measured an5 computed values is 7?, which is considered highly satisfactory for measurements of this twe. However, if Imer estimates of the actual yield obtained by other methods are confirmed, the higher apparent yield obtained from these blast pressure measurements will indi-~te a need for revision of cmrent methods of calculating the effects of altitude on blast overpressw-es. Measurements of the amplitude and time /’&@:EL: L of arrival of the reflected shock were obtained, but because of the large

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offset of–~he+burst point these added little to the info-tion obtained on previous tests.

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a,.,.)The primary objectives of Froject 1.5 on Shct were the investigation of aertiw=dc drag characteristics of actual and idealized shapes when exposed to transient loading conditions resulting from a high yield nuclear detonation. The actual shapes consisted of wide flange I beams and angle beams. The idealized shapes consisted of 3 inch and 10 inch diameter spheres. Project 1.5 had four stations on Sho ‘(CHEROKEE). They = on Yurochi (Dog). At Bokobyaadaa (Able) and I beam, angle iron SX13sphere stations. The only beam stations. islands one and two, and Yurochi (Dog), there were other two locations had The sphere stations consisted of two 3 inch gages and one 10 inch gage. ‘Thesega~es measure the drag forces in three directions: axial, lateral, and vertical, both positive and negative phases. Each component was measured by a four arm strain gage bridge. Each bridge is pre-st”ressedand any imbalance is recorded. The I beam was instrumented as a “simply supported” been. A sensor was used to support each end of the beam. These sensors were instrumente~ with strain gages. The strain gage bridge was so wired that any bending moment would be cancelled. A ball and socket joint was put on each end of the sensor to nullify torsion. As a result the only strain recorded was comp~ession. The records were resolved into a drag force versus time curve.

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The angle beam was instrumented similar to the I beam except for an RESULTS AND CONCLUSIONS to record lift as well as drag. Due to the bombing error on this shot, the records obtained are rather inconclusive insofar as yielding comprehensive drag data. In order to compute drag coefficients, djmamic pressure is necessary. expected GZ. The dynamic pressure records are and were oriented facing meaningless at the present because of the above-fact. The only data recorded by the structural members which is valid is force or rather some undefined component of this force. T The beauty of this type gage is the unidirectional it is omni-directional. fact that rather than being Orientation is not a critical factor as with the other type gages. Actual dr~g force was recorded by the spheres. Although no valid dynamic pressure records were obtained, drag coefficients may be computed using dpamic pressures comwted from These records have not been reduced as yet, due to other shot

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Studies of water ranges and at several wave action generated by the detonation of large MT) nuclear devices are made at relatively close distant island stations by Project 1.9. FU shore recording wave measuring stations (of the Mark VIII type) were active in Bikini hgoon fo~B’’e’o’ee)* ‘n additions Project 1.9 constructed and installed four new type long period wave recorders on Eniwetok, Ailinginae, Wake, and Johnston Islands. These ?recorders are designed to document long period, low amplitude deep ‘=..-, ocean waves of the tsunami type. The recorders operate continuously but only receive significant signals from the large shots at Bikini. In addition to the above instrumentation, a tide gage was active at Ailinginae Atoll, and Sandia Corporation microbarographic stations were operated by Project 1.9 at Wake and Johnston. The tide gage record has not yet been recovered from Ailinginae. All other stations yielded excellent data. The Bikini Lagoon stations indicate there was no significant wave action in the lagoon. Detailed analysis may show the presence of a tackgro~nd-level wave entering the lagoon through the Myu (Nan) channel or possibly the Presence of ~ air-couple~ water wave Disturbance within the lagoon. All shore recording stations in the Bikini area yielded data on overpreesure.

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The results obtained at the farther stations are tabulated below. Station ‘– Approximate Largest Wave Period No. of Johnston 1500 Undetectable above high background * Results by TWX subject to later correction In addition, two or three very long perimi (85 minute) waves about 1 cm high were observed on the Cherokee record from Eniwetok, where the background was very low. Microkarographic records were obtained at both Wake and Johnston Islands. The water wave arrivals reported above are much larger than those reported during CASTLE. This increase is attributed to the facto’. of ten increase in sensitivity of the present instrument over that used It is significant that Ailinginae at 40 miles range received smaller waves than Eniwetok (200 miles). This result agrees with the microbarograph records analyzed for CASTLE, in which the Wshadow zonen for net integrated air pressure impulse was shown to extend at least 30 miles from the shot. It also indicates that these long waves are generated by barometric impulses and not by energy directly transmitted to the water. The wave generation process seems to be inde?en~ent of the scmrce conditions (surface or air burst).

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To determine gamma exposures the point of detonation of a high To draw conclusions from the as a function of distance from yield air burst. data concerning dosage contours and the validity of scaling laws for this type of shot. Standard film badges and quartz fiber dosimeters were distributed at various positions throughout Bikini Atoll and on the ships stationed in the predicted fallout area. 7’Some badges were exposed without ‘~, interruption, while others were exposed in sequence or shielded from the fallout by dropping mechanisms activated after blast arrival. All dosimeters were recovered following the shot. Incomplete analysis indicates approximately l-r dose received by instruments on the reef stations between Namu (Charlie) and Yurochi (Dog), and on the Yurochi (Dog) complex. This is in the expectd dose range for the yield and distance i>volved. The shot point error precluded obtaining useful data from most stations.

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Project 2;& Gamma Dose To measure residual gamma radiation intensity as a function of time at land fallout stations, and to measure the initial gamma intensity vs time for a high yield air burst. The tnitial”gamma dose rate vs time was to be detected by scintillator-photomultiplierdetectors with time response to 10 msec. Residual and fallout gamma intensity vs time was to be measured with ionization chambers and associated electronics. Station locations Usable dab was not obtained for either initial or residual radiation rates vs the.

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To study the contamination of exposed at various orientations to To study the effectiveness of various types of building surfaces various decontamination procedures and thus obtain data on the radiological recovery of military installations constructed from the tested types of material. Panels of the various types of building materials were mounted on a structure so as present various orientations to the fallout. The structures gwere mounted on the forward portion of YAG 39 and YAG 40. Evaluation m-- to be carried out at Elmer, where various be used on the panels. The effectiveness assessed by survey and some radiochemical of the panels and decontaminaticm wastes. No fallout was receive3 by the YAGts decontamination methods were to of decontamination was to be and radio physical investigations

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the neutron flux and energy spectrum as a function of distance from the point of detonation of a Megaton device. To compare the foil detector method of determing dose in rep with chemical and fiOgram Book. The stations consisted of concrete slabs on which were of Project 2.51 stations for dlluBib The steel plates were oriented so that they would be perpendicular to a line from the station to the proposed point of burst. In order to facilitate recovery, the neutron foil detectors were mounted on the steel plates by means of specially designed ‘quick disconnect cl~Ps’?. The chemical and semiconductor dosimeters were placed in three inch diameter pipe nipples and were claped to a 3/8n Cable stretch~ between two eyebolts mounted on the concrete slab. The following detectors were placed at each station: Neptunfum Fission Threshold

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Zirconium Activation Threshold Counting of all samples was accomplished No neutrons were detect~ at any of error in the air drop. at the pacific Proving Grounds. the stations, due to large

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To determine experimentally the radioactivity in various typical soil mimples induced by irradiation …