Commanders Report, Task Group 7.1 (Hardtack I Operation) (Deleted)

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2.1 Task Unit 3, IOD Wograms J( w L. Structures anc Zquipment 26

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A total of U f%lJ scale tests ad one szfetytestwere c=rricdout by for this reasonwerefiredon land. The otherthirteenwerefiredon barges to facilitatercmiinessand mirdndzocent-mimtion problems. The major objectiws of the ccnildbe ~ouped aroundsix riiin Laboratoryat the begtiing of the operation

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In or Conductedby AGenciesof tho Governmentof coordinationwith the wwious scrticesand the AEC, the follo~dng: 1. Appro~iatetcst Pogrsms tobe conductedin conjunctionwiththo 2. The selectionof the appropriatenucleardevices. The Chief2LFWF formulatedthese plans cnd alsoa nmber of sepamtc projects to be conductedon selecteddevelopmentdetonations. ning and field implementationof the DCl ‘.feaponsEffectsRogram, Operation chargedwith cmducting the scientifictests duringthe operationalphase at the EIW. The approvedmilitarywea&n effectstests projectsin PrograEIs 1 through6 ‘and8 and 9 are outlinesbelow and discustiedin Chapter2. duringthe operation. The DOD IleaponsEffects Programswere organized

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Promam 1. W programms desigmted primarily to oWln data from underwater bursts,such as blastoverpremmreand groundmotionrecoxds. This informationw necessaryto asce~ln the effectsof underwaterburst geomet~ and to understandthe conditionswhich variousstructuralobjects,such as Pronam 2. This programobjectiveswere: 1. To determinethe grossradiologicalhazards resultingfraaunderwcter inhalationof contaminationenteringthe ship via ventilationand com2b To collectneutronenergyspectrumdata to supphment the presently weapons. Promptneutronmeasurementswere to be determinedfroma VHA underwaterbursts on surface designedfor determim.tionof the effectsof and sub-surfacevessels,and for the studyof varioustypesof lend stzwcturesunder variousloadingconditions. The informationobtahsd by-bth program 1 ands wiJl be used to aid in fomnulation of operationaldoctrine~particularlyInsofaras deliveryrcngesand tactics for bothsurfaceand sub-surf!acevessels.The informationobtained ~ the responseof ship structureswffl be used to providecriteriafor testedunder both long and short duration& blasts,and deep reinforced concreteslabs testedunder blastloading,will be used to determineconstructioncritericfor futureunderground structures.

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~. This progiemm designedtodetetie the effectsof nuclear weapon9cm abcraft structuresl Nuclearweapondeliverytg manned aircraft Is oftenaffectedby the weapons1 blast and therml effectson the delivery aticraftand by nuclearradiationon the crewc Test data has indic~tedthat tist Inputsand skin temperaturerise can be predictedwithin satisfactory limits,but that predictionsof the aircraft~s responseto these inputsis Pro~sm 6. This programwas to study effectsh L categories: 1. Electronicequi.~ent10Cated at variousdistancesfrom the zero. point was to collectdata to determim the feasibilityof us- the EM pulse from w nucle= burst for long and shortrangedetection,- to study the firekll and nuclearcloud with radar for doterminggro?ind zero and yield. be undertakenof the ionization effectsof particularlyas they might effectcomzunicathe ionospherefor propagation. be made on the deleteriouseffectson fuses and their ccunponentsas a result of gsmma rays and neutronsfrom nuclear 4. On the underwatershots,experimentswere to be made to determine the feasibilityof using nuclear explosionsfor clearingof mine fields. RoRram8. This Pogram includedthe evaluationof Laboratorymethodaof of the programpmticipationwas to ixprestigatethe littleknown thermal phenomenaand the @rameters which have a directrelationshipon the damage producingthermaleffectsfrom the fireballof high altitudedetonationsand the predictionof those parametersfor other heightsand melds. ~clud~ was to be the photographicmeasurementof the fireballr.adiuetixm history h’o~rsm9. This generalsupportprogramincludeda study of effectof de-

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tonationeon ICHJMeaponain flight. Included of effectson radarand communicationsas well as basic effectsstudies. A special project(Project9.2) was assignedthe missionof liftinga weapon

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OBJECTIVES; DEVICES, AND WEAPONS The mission and designed purpose of Program 32 of Oper.%c.’l HARDTACK was to measure phenomena of Interest to the Atomic Energy Commission, to develop and test instrumentation tec!;;:jrlwr compatible with phenomena associated with large nuclear bwst~ at very high altitudes, and to measure effects of Interest to the Department of Defense. Program 32 also provided the s*JTp~:k required by the AEC In furnishing the warheads for these tes:s. Program 34 included ten Sandla service projects which were performed for elements of Task Group 7,1. The objective of Program 34 was to provide information, devices and systems to Task Units 7.1.1 through 7.1.4. The projects within this program not only met every re qulrement but in general provided even more information than

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to under~rouncieffects would be ~.net-;.,hl)+r..C+:u5WP.Sc:loser.to provide a Airblast. Complete air blast data were obtained on both shots, Gverpres-

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preswires data at 31 hci.g~,tsrequir[+further data reduction before cm be reported. ~kcimum overpreasfiuresfrom both shots when scaled at standard sea level conditions agreed well tith e 1.6 kt free 2ir pressure curve. Neither shot showed any ev-.denceof a precursor; ~i the case of Koa, this was contrary to Predictions. C:*ctusoverpressurcs show an unusually slow and as yet unexplained decay fIw the first 25-40 msec, to measure accelerations at various de~~hs ,Q 1301 and relative displacement between the gro’md surface and the 5C and llC toot depths was installed on shots at ranges corresponding to predti.:tdpress’~re~of 600,200 and100 Grouid accelerations up to L120 ,;orlio:tand 616 g on Cactus were.reNTS; wave forms were influenced con;iderah7.yby energy transmitted through the earth from ranges closer to the bur;t,, !iorizontalaccelerations were higher than expected. Peak vertic:~ ~~celerztims sho~;eda more rrpid decay with predictions.Koa craterd.~,vnsionso:f::25~radks and 1601 depth were verticalorientations, were burisd for bet} shots at verious depths to 20 feet at the predicted 200 psi pressure range. Results from the few drums recovered at this writing and from limited electroni: dat,~available indicate soil pres-~ sure decreased with depth to lC feet arx”tt Len rose to surface level values at

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Vibrating Reed ~ges. Canisters with Vibra!inflreed gages were ran~es of 75 to 200 psi on both s~.ots,with their tops flush to ad mounted to the floor of Project 3,2 underground structures. gage provided a reading of maxinr.mver+.icalor radial displacement for G ~iv~: show no simple correlation with P1.wr,bbc)kda”a. Vertical and radial.displacements for Koa were much lower than exyected fr~n !~TSdata. Vertical.disthe burst altitude reduces the m?r:y ia~pe:rim:as air blast, Or.shot Yucca, the objective was to deteruine the cl-,cractf:ristic of a blast wave at altitudes of about 90,0C0feet in order to provide aIr::curate basis for sc~.lingto higher and lower altitudes. FiIJecanister: t;mtainir:flgages were to be susCanister functions, includjng t’ur.ningcn t![erecorders} were to be controlled by a command transrztter abo~rd the U.5SBCU?. Project did not obtain its objective because of failure of this tran,snitt.~rabout two minute:;before shot

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Their prinmry objective was to ch$ain the f-ee-field input data neededfor determination of safe delivery ana c:it.ic:~?.d,7rageranges for submarines, aircraft, and surfacevesselsoperating in the vicinity of underwater nuclc~r detonations. In general, there was L r+.tkl>-th3ro’@l mount of inforrn~.tion ater explosion effects. results on scalin~ for isovelocit.yc9J2tiitLIn and to st-.idythe effects of corded at the 1311-4’74while at XI-592ncIda’.~“~~asohta~n(=d. The data generally the pressure field ~t E38F37frange and also Influenced peak pressures at depths thoroughly analyzed, primarily by EL, f:>rrefraction effects using the shotj% time underwater temperature field provi~ec:by CN’R- Hydrographic Office

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on the basis of and pre-shot bt data taken f;or three points in the array Air Overpressure. The I?CLinstalled three near surface gages @n Vessels ~~ of 5001and 1000$. Records were obt~;n~d from two gages from the balloon distinct pulses; it,is beiieved the first ~ulse results from underwater shoe}: transmitted across the water-air xterf:ce wc the second from bukibleeffects. Surface Phenomena. The Scripps Institute rf oceanography (S10) measured water base sur~e, etc. Pnotogaphy from 4 Pir-rr.f’,bidseveral surface stations was the principal means of d:ta collcrticm ‘;iththe clear weather, photoexpected to provide thorough doc’v.ment-tumcf the pl]enonenaof interestt used by Amour was the previou:‘.:;sucnes?f~ i,y.mm:L.J+,hod.?%? lack of z Underwater Pressures. NCL successfully neasured underwater pressures :Atsixface zero,at depths from 10 f~?etdo~ to UC feet} covered the Flressuiieranse

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ical predict”lons and high explosive work. peak ~egsu.res decayedwith distance at a significantlyhigher rate than ,rould occur h. free waterl ~Ae mafi shock was preceded by a induced by ground shock. At observed; at 3000’ range and small gradual.increase in pressure which was close-ti stations, near ideal wave forms were bepnd, wave forms were complex. A ~zavitat~on pulse was observed at all stations et 750’1range and beyond; maximum cavitat- * Overpressures. NOL used a combination of 32 rockets, five balloon stations, end seven surfacestations :CJ~ccw:,entthe air overpressure-tine field twenty rockets recovered fielded usable d+ta; ei@t additional racket records may yield usable data after further ev_.171:1.tion.Five cf the seven surface stations and one balloon statix produced good records. Surface data show good agreement with predictions based on ;~ ~2s1Jts and indicate the me of 10@ efficiency in scaling HE data to the nuckcr case is reasonable. Peak pressurerecorded,1.88 psi, -5 at ~~CO’ altitudeat range of 2000 feet fron concentrated on water waves. iT<cGpro~’i:~+d:xcellent photo.naphic coverage of surface phenomena from L aircraft and several surface stations, NOL Obtained good records cf temperature and hl.rniditychmges at 5 stations withti the base surge. ‘Theserecords show well defined temperature changes which correlate well with arrival of base surgI:as visually obsermd. S10 successfully measured the waterwaves from a ~mber Gf stations and by e.variety of means. The most irkeresting of these were three stations about 1700tfrom

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It was steep fronted and had a 22 foot span from crest to trough. liydmdynamicYields. ARF attached two st,ri.ngsof blast switches and one doppler system to a taut cable mnnin~ outw.:rdfrom the Umbrella device with the ain of measuring the time interwl bt>t’weerclosures of the blast switches and the rate of phase change of an ~.f. signa~ fed into the doppler cable. De.ta was received in the zero LCU and telemetered t.oa remote location. .~.ecords were obtained for the blast switches only as the doppler cable WS crimped yields are determined, however, showed an zs yet Une.s?laineddeviation from the slope expected from ‘;igwamresults, A craterof about 201 depth and 15CO~ fli.: ‘-;ter“1’2sfmmd. Program 2 included ten projects, whi.:kcould be grouped htlo four cateShipboard Radiation Vulnerability, It WFS the object of this study to docuby shots?:ahooand Umbrella. Both total gama dose histories were measured by film-badge do:imetry and three target destroyers

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supplieddata on radiationat loc,+ions 72~rf?5ent@ major battle stations; underwater GITR instrumented.<.ansl~~piie?cti. m radiation in directionally shielded GITR statims r.o’m~t?don deck supplied radiation from remote sources. the water; and Radiation histories were obtatied or mi:.yone destroyer during shot ‘.Jahoo,because of shipls power failures on the other two. Raaizt~on histo:$ic~ ranged between 6CQ r received %-thin 0.5 minute at 2,0C41feet zero and 1+5 r received within 2 T.L-,’Jies;t 8JO00 feet. Dose the waterline, and dose reduction factor= ;_P+aterthrm 9 were obtained o,fiy present a high percentage of the ttd :’,’di.:.:iorobserved aboard the ships. not contribute to the tatal rndiatlon r.e:.svi:daboard S:iip. Data on gammaShipboard Contamination Xn~ress. This I.KSa study of the external and inby underwater nuclear detonations. Four cmp-rtrnencs of the ?)D-592wsre instrumented witn total and ti.~e-incrementa~,dir Sznplersj :;-&-facesamplers, animals (mice and guinea pigs), and P.ITRi:lstru.r.er?t~.tion.Rates of air flow for ventilation and boiler combustion far t!-einstrumented compartments were controlled so as to be representative of these e~ected under nuclear-attack

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and animal data were obt:med, ‘he failure of a project ttiing circuit durhg shot Wbrella resulted ~.r,10SS of time-dependent atiEsttiates of the titernal dose due ‘.o~LLkd.atiOn ti the test compartments during :iahooindicated that the doses wtre belo’irthe threshold for acute exposure but that posslhle chronic ef:fectsmight be produced. Sirilar estimates for Umbrella fidicated the doses Mere belo~ the threshold for the engtie room. Umbrella estiiites of the external-dm’- rates in the test compartments compartments total dose ret,e, tation located on coracle pl~tfc]rms,as i:’.llas on tic m’.jortarget ships. These measurements were supplemented ty th:se c>ftotal,ga.naadose made with floating film packs located throughout the tmget array. Increments co3J-ecad residual doses and tiformation on radiation fron ~a~~.:~c?ive~at,2ri?Q.ssuspended in the Durine both ‘)~ahooand Umbrella, 1: was gamma dose occurred within 15 riunutesafter fcund that nearly all of the total zero the and was due to the Hcwe~rer~the records of gamma dose rate vmsus time obtainedfrom the two sh(ts show pronounced and character- P Gtmma doses h excess of

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100 r occurredwithin the first 15 xi.nu~esa+ downwind distances less tham due to deposited radioactive materml or,the ships and coracles ws from li~k.t to insignificant. A study of the downwind ~LTm data showed that a distance of approximately 23,000 to 28,000 feet from surface zero should be ‘ni:tiltab~~ Johnston Island part of the Gperation JS ro~erc~’in the swzmary pertaining to Teak and Cran~e. measurements were to have been nwde with z L~ A scintillator-photodiode protidecorrectiondata for the @ma res:mnseof the detector. Two types of gamma detectors were uscdt All data were to have been recorded am: ing ground station. The instrumentatlcr w:g cont:il]cdin a canister ouspended 2$750 feet below Ih nuclear devic{:by rems of a nYlon line. Due to failure of the cormnd transmitter, whict {ontrollcd the canister operational instrumentation ‘wasinactiv~’at zero time, and no data was Neutron Flux lleaswenents. This was a prc,~a.mto document th~ neutron flux

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and spectmm as a function of tiist~nce;“~r ments, threshold~ct ivation and fission det~ctors were exposed as a.funciion this objective, the p:.ojcctpartici~=?ed during shots Yellowwood and The measurements were extended d’:.-ln“ the field phase of the operainclude shot Ouince, md tkis particip~tion is covered in the portior report relating to th-t detonation. To make t$e necessary mcasureof distance from the Yellowood (Ind‘:lalnut~ero points. These detectors inplaying the detectors with distance, a kuclyli~.ewas used. The line extended Fallout Wr@ing. This was a d~t?rn~.~’-’.” .O? the relative contribution of certain isotopes to botfilccd ?-ridworld-w:dc fallout and the use of this Wormation, M possible, to det~~ine :,hefraction of total bomb debris The rocket smpling was to ~ave been accomplished with rockets being developed by Uc;til%oject 21.3. Gas and ~articulate sampling of the residual cloud has accom~lished by >5’72 aircrqft lr,r!er the technical supervision of

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These collectionswere made at an altitudeof 1000 feet byl&50 aircraft. and this portionof sampleawere not collectedfrum shots Koa and ‘;fiut, the projectwas cacelled prior to Oak. SuccessfulB-5T> of the Koa falloutwere made; however,earlyanalysis“of the samplestidicatedthey had been contamhx=.tedby debrisfrom shot Firj firedthe previousdayat Bikini. For this reason,projectparticipation Valnut and Oak. Collectedsampleswere returnedto the continentallaboratoriesfor analysis,and the resultantdata was not amila.bleat the tine this reportwss written. Garma Dose iieaswvenents; after shot Quincewas scheduledas part of (perationHAHDT,’~CK~Project2.4, this shot. The discussionof the participationof these projectsis included in the portionof this reportdevotedto shot @uince. The objectiveof this programwas to provide‘informationon the effects of nuclearbursts on ship structures and equipment, and on various land gated. Five of the eightprojectswere concernedwith the ship structures 2 (

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cernedwith land structuresresponseto ah blast. preliminaryto OperationHARDTACKa seriesof testswere run employing Island,CaliforniainJanuary1958. A seriesof four large, specialshaped ulate underwaternuclearattackagatistthe DD 5924 The seriesof tests wcs carriedup to the thresholdof shock damge, but stoppedafter detonationof the third chargeto avoidthe ~oba.bilityof swious damageto the DD 592 prior to the latermain H.UU3T.iCKfull-scalenucleartests. The resultstidicatedthat the shock wave pressuresatisfactorilysimulatedthe initial shock waves from a nucleardetonation. . detonations. In addition,three manned fleet operatingships, submarineSSK 3 and destroyersDD 728 and DD’826,had a minor aboardand were also exposedto !khoo. The SSK submarinemodel, SQUAiJ29, were also exposedin 3, unnamed, and a 4/5 scale ponse of equipnent,as well as equipnentfoundationswhich includedhulls, bulkheads,decks and superstructureswre documentedby the use of a total of 325 velocitytime meters and self-recordingshock-spectrumgages and LO highspect to dama~eto machineryand equipmentnay be made.

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The hull.was plasticallydeformedbut did not rupture. Four of the ten externalballasttanks rupturedand all wereseriouslydishedresulting in some 10SS of bu~cy. SSK3 was suhnergedat periecopedepth and operated

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coral sand, simulating partiallyundergroundstructureswas studied. Three in the 80 to 180 psi peak overpressureregionfroma empiricallydetertie the responseof such struct~es. tested h the 90 psi peak overpressureregionfrom-a 17 kt surfaceshot to detefie the effectsof short-durationblast loading collapsedon the side away from ground zero~ The collapseapparentlywas ture. The following faflureof the shell platesat a bolt:?dhorizontal seam, above floor level on the collapsedside of the strucresultshavebeen noted on the other 3 structures: peak overpressurefrom shot Koa suffereda completecollapsesymmetricallyaboutthe crown. The third~25-footspan structuresubjectedto a 180 psi peak overpressurecollapsedcompletely. The dynanicbehatiorof deep (thick)reinforced concreteslabs in the overpressureregionsof …