CHIEFS 0F STAB I 1 5 SECRET R0 500 i a - unu- DRAFTER EXT- PRECEDENC ER SK ADDRESSEE FR JCS EVALUATION BOARD 1 0 PRIORITY 2 3 RELEASED BY 2 ROUTINE 4 JCS DRESSED ONE 06 JULY N6 3 BASEGRAN DECODED BY MURPHY PRIORITY 10 BARNARDE - 11 BY BY DEFERRED 1-2 DITTOED 13 ROOTED BY TENNANT BY - BASEGRAN 14 UNLESS OTNERNISE INDICATED THIS DISPATCH NILL BE TRANSNITTED NITN DEFERREDFRECEDENCE AND AS ADMINISTRATIVE IF OPERATIONAL 15 RAGE 1 OF 7 - - 18 Originator in DATE AND TIME GROUP Use G C T ON OUTGOING DISPAT HES PLEASE LEAVE ABOUT ONE INCH CLEAR SPACE BEFORE BEGINNING TEXT TT20 FOR JOINT CHIEFS OF STAFF FROM JCS EVALUATION 21 85 IO WASH TD JOINT CHIEFS OF STAFF 22 33 I IN COMPLIANCE NITH DIRECTIVE FROM THE JOINT CHIEFS OF STAFF 34 DATED 27 FEBRUARY 19h6 THE EVALUATION BOARD PRESENTS THE FOLLOW4NG 2 PRELIMINARY REPORT OF ATOMIC BOMB TESTEA HELD AT BIKINI ATOLL ON 27 1 JULY 19H6 THIS REPORT COVERS GENERAL OBSERVATIONS ONLY EVALUATION MOST ANAIT FULL COLLECTION AND ANALYSIS OF DATA FROM 30 OBSERVERS AND INSTRUMENTS AND WILL BE REDORTED AT A LATER DATE 31 2 THE BOMBERS OF THE BOARD INSPECTED TARGET SHIRS THE DAY BEFORE 33 THE TEST WTTNESSED THE FROM AN AIRPLANE 20 MILES DISTANT 3 AND THEN TD WITHIN 9 MILES OF THE ATOLL FOR A BR NF VIEN 36 ON THE FOLLOWING DAY AS SOON AS SAFETY CLEARANCE HAD THE MEMBERS FLEM To BIKINI AND BEGAN THEIR EXAMINATION OF SHIP 39 DAMAGE MANY PHOTOGRAPHS HAVE BEEN STUDIED AND MILITARY AND 3 SCIENTIFIC SPECIALISTS INTERVIENED IN AN ATTEMRT TO OBTAIN AN OVER-42 ALL UNDERSTANDING OF TEST RESULTS RRIOR TO THE COMRILATION OF ALL 43 44 HE DATA 45 OBSERVATIONS IN THE BIKINI AREA THE BOARD CONSIDERS THATAINNTESHNO 45 3 FROM ITS PREVIOUS STUDY OF THE PLANS FOR THE TEST AND FROM 49 NO I ADMIRAL No 2 FILE No SN OR CNARTR Agi s ngmmE Si A 52 ET - Hi 21SNME CLASSIFI - Hag sron$yginH z gs gg th CTop Secre p ngg lg on font ed in 76 l aiions COPY Woo R I OPNAV 19-78 w v SECRET DISPATCH 3 I - DRAFTER EXT ADDRESSEES PRECEDENCE NAILGRAN ADDRESSEE 1 FROM - PRIORITY 2 RELEASED BY ROUTINE 3 DEFERRED 5 DATE 5 BASEGRAM 6 7 TOR CODEROOM 8 9 DECODED BY PARARHRASED CHECKED 11 BY arme DEFERRED 1-2 BY BY 3 BASEGRAN if UNLESS OTHERWISE INDICATED THIS DISPATCH BE TRANSMITTED WITH DEFERRED PRECEDENCE AND As IF QPERATIONAL 15 CHECK RELOR 16 PAGEPA 0F 7 0517312 35 17 Originator fill in DATE AND TIME GROUP I Use G c ON DISPATCHES PLEASE LEAVE ABOUT INCH CLEAR SPACE BEFORE BEGINNING TEXT '7 20 HAS WELL CONCEIVED AND EXECUTED BY THE SERVICES IN CLOSE COOPERATION 2 WITH A LARGE EIVILTAN STAFF IT IS SATISFIED THAT THE CONDITIONS OF 23 THE TEST HERE HELL CHOSEN AND THAT THE HIGHEST SKILL AND INGENUITY HAVE BEEN USED TO QBTAIN A MAXIMUM AMOUNT OF DATA IN UNBIASED 26 SCIENTIFIC MANNER IT BELIEVES THAT THE COMMANDER STAFF AND 2 OF TAEK FOR THEIR 29 EXCELLENT PERFORMANCE AND THEIR NOTABLE COOPERATIVE SPIRIT 3 h EFFECTIVE PRECAUTIONS APPEAR TO HAVE BEEN TAKEN T0 SAFEGUARD 3 PERSONNEL AGAINST RADIOACTIVITY AND ASSOCIATED DANCERS 34 a 5 THE BOARDS PRESENT INFORMATION IS THAT THE BOMB EXPLODED WITH AN 35 APPROACHED THE BEST OF THE THREE PREVIOUS ATOMIC 2 I BOMBS OVER A POINT 1500 TO 2000 FEET HESTERLY OF THE ASSIGNED AND AT APPROXIMATELY THE PLANNED ALTITUDE 49 6 THE TARGET ARRAY IN NO SENSE REPRESENTED AN ACTUAL NAVAL DISPDOTTOON BUT WAS DESIGNED TO OBTAIN THE MAXIMUM DATA FROM A SINGLE EXPLOSION 43 THE MOST IMPORTANT EFFECTS PRODUCED BY THE BOMB ARE THE DESTROYER AND 2 TRANSPORTS-SANR AND ANOTHER DESTROYER 45 IT LATER SANK AND THE JAPANESE CRUISER SAKANA SANK THE No I ADMIRAL No 3F-I OR CHARTROOM N0 '4 SPECIAL i Z OPRAV 19 78 32 1 I I UP SECRET any lug u DRAFTER EXT ADDRESSEES PRECEDENCE TA ASTERISK MAILGRAM ADDRESSEE 1 FROM PRIORITY 2 - 3 RELEASED BY ROUTINE 4 3 DEFERRED 5 DATE BASEGRAM 6 7 TOR CODEROOM 8 I PRIORITY 9 DECODED BY mm 10 PARAPHRASED CHECKED BY BY DEFERRED 12 DITTOED 13 ROUTED BY BY - BASEGRAM 14 UNLESS OTHERWISE INDICATED TRIs DISPATCH WILL DE RITR PRECEDENCE AND AS ADMINISTRATIVE IF IPERATIONAL 15 PAGE 3 OF 7 0517312 NCR 361 16 17 I 7 Originator fill in DATE AND TIME GROUP 7 Use G C T 19 ON OUTGOING DISPATCHES PLEASE LEAVE ABOUT ONE INCH CLEAR SPACE BEFORE BEGINNING TEXT 20 21 FOLLOWING DAY THE SUPERSTRUCTURE OF THE SUDMARINE SKATE WAS 50 22 BADLY DAMAGED AS TO MAKE IT UNSAFE TO SUBMERGE THE VESSEL THE 23 24 LIGHT CARRIER INDEPENDENCE WAS DADLY WRECKED BY THE EXPLOSION 25 GUTTED BY FIRE AND FURTHER DAMAGED BY INTERNAL EXPLOSIONS OF LOW 26 27 ORDER INQLUDING THOSE OF TORPEDDES ALL THE ABOVE VESSELS WERE 28 THE EXPLOSION PDINT 29 9 a 30 B NUMEROUS FIRES HERE STARTED OR OTHER SHIPS INCLUDING ONE ON 31 A DISTANT WHICH WAS APPARENTLY DUE TO SOME UNUSUAL 32 33 CIRCUMSTANCE SINCE THE OTHER FIRES HERE MUCH CLOSER HERE IT SHOULD 34 BE REMEMBEHED THAT THE TARGET SHIP DECKS CARREED A GREAT VARIETY OF 35 36 TEST MATERIAL NOT ORDINARALY EXPOSED ON THE DECKS OF NAVAL VESSELS 37 C THE ONLY MAJOR COMBATANT SHIPS WITHIN 1%2 MILE OF THE EXPLOSION38 39 POINT WERE THE BATTLESHIPS NEVADA AND ARKANSAS AND THE CRUISER 40 THE BLAST STRUCK THESE FROM THE AFTER QUARTER 42 LITTLE DAMAGE WAS DONE TO THEIR HULLS OR THEIR MAIN TURRETS BUT SUPERSTRUCTURES WERE BADLY WRECKED THESE SHIHS WERE UNQUESTIONAZLY44 a M r i g5 PUT OUT OF ACTION AND WOULD ALONG WITH MANY OTHERS WITHIN OF A 46 MILE HAVE REQUIRED EXTENSIVE REPAIRS AT A PRINCIPAL NAVAL BASE 47 48 49 No I ADMIRAL No 2 FILE No 0R CHARTROOM No 4 SPECIAL 50 51 52 Handle only in accordance with FTop Secret instructions contained in ArtiCTe 76 Navy ReguTations OPNAV 19 78 SECRET DISPATCH g my l' 36 DRAFTER EXT- ASTERISK MAILGRAM ADDRESSEE 7 FROM PRIORITY 2 I RELEASED BY 2 ROUTINE A 2 DEFERRED DATE BASEGRAM TDR CODEROOM DECODED BY PRIORITY h PARAPHRASED CHECKED ROUTINE BY BY 5 DEFERRED DITTOED ROUTED BY BY BASEGRAM UNLESS INDICATED MSFATCTI BE TRANSMITTED mm PRECEDENCE AND AS ADMINISTRATIVE- IF OPERATIONAL - CHECK BELDR RAGE 0F 7 DJ 0517312 NCR 36h7 Originator fill in DATE AND TIME GROUP GI CI TI DN OUTGOING DISPATCHES PLEASE LEAVE ABOUT ONE INCH CLEAR SPACE BEFORE BEGINNING TEXT O OTHER SHIPS IN THE TARGET ARRAY SUFFERED DAMAGE IN VARYING DEGREE DEPENDING ON POSITION AND TYPE OF DHIP BUT THERE WAS LITTLE DAMAGE AT DISTANCES GREATER THAN OF A ILE E THE PRIMARY MATERIAL NOTED WERE DUE TO BLAST BUCKLING OF DECKS AND AND DESTRUCTION OR DEFORMATION OF -C9NSTRUCTED EXROSED OBJECTS INCLUDIND STACRS MASTS AND ANTENNAE SECONDARY EFFECTS WERE DUE TO FIRE AND IT IS NOTEWORTHY THAT ARMY STORES AND MISCELLANEOUD EQUIPMENT PLACED ON THE DECKS FOR THE TEST PROVED MORE VULNERABLE THAN NORMAL NAVAL DECK GEAR IT SHOULD BE POINTED OUT THAT SINCE THE TARGETS CARRIED NO PERSONNEL THE FIRED WERE UNCONTROLLED AND UNDOUBTEDLY THERE WAS MORE DAMAGE THAN THERE WOULD HAVE BEEN UNDER BATTLE CONDITIONS ALTHOUGH CONSIDERADLE AMOUNTS OF EXPLOSIVE ORDNANCE WERE EXPOSED ON SINGULARLY DECKS AND IN GUN TURRETS THERE IS NO INDICATION ON SHIRS WHICH REMAINED AFLOAT THAT ANY OF THIS MATERIAL WAS EXPLODED BY DIRECT REE ACTION OF THE ATOMIC BOMB FIRE FIGHTING SHIPS ENTERED THE TARGET AREA AS SOON AS THEY COULD OBTAIN RADIOLOGICAL SECURITY PERMISSION AND SUBDUED A NUMBER OF FIRES No I ADMIRAL THE SPEED AND EFFICIENCY WITH WHICH NO SPECIAL- andle only in accordance with Top Secret instructions contained in Article 76 Navy Regulations COPY 19 78 I 4 Ind flaw 18 com H0 50 51 52 1 03 39 IQ '09 6 '1Vl33dS 81 61 Avudo Ana a 0111v u pauxuquoa suorqonaasur 134335 domu H11 eouupgosoe u uo a puh '3113 I 8 W053 ILVIEVA H1IM 01 GENSISBG QVM 1831 3H1 9 7 HanOHrw noao oamaaxam mvoumms ItNOdn 133333 18V38 3H1 JO ANV GNOAEQ WVDIGBN 3H1 30 8180638 3H1 1IVMV 01 EAVH 311M 139aV1 1 3H1 30 331W NIH1IM NO NI 3SOH1 303 HBIH N338 BAVH 18000 ON GWHOM 1SV38 01 300 83113V03V3 1 '8133333 WVQIBOTOIGVB JO BSVSOG 3VH133 01 N338 3AVH GWBOM SleQ 3H1 NlHiiM 1VH1 EDNEGIAB SI 333H1 $38013 31$83d 3 leS 01 39VNVG 18V38 30 V38V 3H1 9 '5133333 3V31903010V8 3H1 N338 BAVH 1H91H 83A31VHM A8 A331V103HNI 68 3 gr 2 83N338 BAVH 10M GWHOM ENDS 3H1 JO MOGVHS 3H1 MDBG NBAE BO diHS 30 33HH 3H1 0383133H3 1VH1 JO 3H1 Si 11 SNONV N338 3AVH GTHOM 1VH1 3H1 3H1 A8 $133333 Nana HSV3J 3H1 JO NOILVNIHVXB 3 1S03 N338 EAVH 381M83H1O 1H91N HDIHM NOI13V QNOQ 30 33N3GIA3 1X31 9N1NN1938 380338 aavas avawa HUN 3N0 1008V 3Av31 38v31d we '3'9 GNV 31V0 11 1401319329390 1 095 HQN 3 ZLEZLSO l 10 9 39M SY GNV Hill 39 11IM 3SIM83H10 5333 A8 A8 031003 0301110 A8 A8 03X03H0 A8 0300330 NV893SV8 03883330 3N11008 nonlvwaoJNI N0083000 301 03333530 '3N11nou 31V0 AB aisv31aa 803 N083 NVEBWIVN M91331 v 'ixa uaigvaa 1 38335 as OBOERVATIONS A -3 I qr 1 Hm I 1 VP SECRET DISPATCH V DRAETER EXT ADDRESSEES PRECEDENCE ASTERISK MAILGRAM ADDRESSEE 1 FROM PRIORITY 2 'z 3 RELEASED BY ROUTINE 4 2 DEFERRED 5 DATE 3 BASEGRAM 6 7 TOR CODEROOM- 3 9 DECODED BY- PRIORITY In PARAPHRASED CHECKED ROUTINE 11 BY BY DEFERRED 12 DITTOED RODTED BY BY BASEGRAM 1 UNLESS OTHERNISE INDICATED THIs DISPATCH HILL 8E NITN PRECEDENCE AND AS ADMINISTRATIVE IF OPERATIONAL 15 6 OF- CHECK BELOW 16 7 0517312 NCR 36h7 18 Originator fill in DATE AND TIME GROUP Ilse G C T '19 ON OUTGOING DISPATCHES PLEASE LEAVE ABOUT ONE INCH BEFORE BEGINNING TEXT 30 BREOICTIONS THERE HAS NO LARGE HATER WAVE FORMED THE RADIOACTIVE21 RESIDUE DISSIPATED IN THE MANNER EXPECTED NO DAMAGE OCCURRED 22 BIKINI IBLAND ABOUT 3 MILES FROM THE EXPLOSION CENTER 3 9 FROM WHAT IT HAS BEEN AND FROM WHAT IT HAS ABCERTAINED FROM 26 DATA NON AVAILABLE THE BOARD IS ABLE TO MAKE CERTAIN GENERAL 2 29 THE ATOMIC BOMB DROPPEO AT BIKINI DAMAGED MORE SHIPS THAN HARE 3 EVER BEFORE BEEN DAMAGED BY A SINGLE 3 DECK PERSONNEL FROM THIS TYPE OF BOMB - 32 B THE TEBT HAB PROVIDED ADEQUATE DATA BE A BORT NECESSARY FOR THE33 REDEBIGN OF NAVAL VESSELS TO DAMAGE TO BURERBTRUCTUREB AND 34 BECAUSE OF THE NATURE OF THE36 FIRST TEST AIR BURST LITTLE INFORMATION HAS BEEN OBTAINED ON HULL 37 EFFECTO SECONO TEST WHEN A BOMB WILL BE EXPLOOED UNOER WATER C A VABT AMOUNT OF DATA HHICH HILL PROVE INVALUABLE THROUGHOUT SCIENTIFIC AND ENGINEERING FIELDS HAS BEEN HARE AVAILABLE BY THIS TEST ONCE MORE THE IMPORTANCE OF LARGE SCALE RESEARCH HAS BEEN DAMAGE TO HILL BE BTUDIEO BRECIFICALLY ORAMATICALLY DEMONSTRATED THERE CAN BE NO QUESTION THAT THE AND EXPENSE INVOLVED No I ADMIRAL No 2 FILED517312 IN THIS TEST HAS BEEN AMPLY JUSTIFIED BOTH BY NO OR CHARTROGM No lI SPECIAL Handle only in accordance with Top Secret instructions containe in Article 76 Navy Regulatio s COPY OPNAV 19-NO- 3 I DECLAbsuunu I mm- w UP SECRET DISPATCH DRAFTER EXT- AOORECSEES PRECEDENCE ARTERISK If RAILORAM ADDRESSEE I 1 FROM PRIORITY 2 3 RELEASED BY 2 ROUTINE 4 2 DEFERRED 5 DATE 3 BASEGRAM 6 7 TOR CODEROOM 8 9 DECODED BY PRIORITY 10 PARAPHRASED CHECKED ROUTINE 11 BY BY 5 DEFERRED 12 DITTOED 13 ROUTED BY BY BASEGRAM I4 UNLESS OTHERWISE INDICATED THU DISPATCH BE TRANSHITTED WITH DEFERRED PRECEDENCE AND AS IF OPERATIONAL 15 CHECK BELOW 16 RAGE 7 OF 7 0517312 NCR 36h7 Originator fill in DATE AND TIME GROUP A Use G C ON OUTGOING DISPATCHES PLEASE LEAVE ABOUT ONE INCH CLEAR SPACE BEFORE BEGINNING TEXT 20 THE INFORMATION SECURED AND BY GREATLY NARROWING THE RANGE OF 2 SPECULATION AND ARGUMENT MOREOVER IT IS CLEAR TO THE BOARD THAT 23 ONLY BY FURTHER LARGE SCALE RESEARCH AND DEVELOPMENT CAN THE UNITED z STATES RETAIN ITS PRESENT RODITION OF 3CIENTIFIC LEADERSHIP THIS 26 7 MUST BE DONE IN THE INTERESTS OF NATIONAL SAFETY 8 29 10 THE BOARD DESIRES TO SAY THAT IT HAS THE EULLEST COOPERATION 30 OF THE TASK FORCE COMMANDER AND THAT EVERY OPPORTUNITY HAS BEEN 31 32 AFFORDED IT IN CARRYING OUT ITS MISSION THE MEMBERS OF THE BOARD 33 HAVE HAR ACCESS TO ALL DATA THUS FAR ACCUMULATEO AND HAVE HAD EVERY 34 FACILITY FOR PERSONALLY INSPECTING THE REEULTS OF THE TEST 3 SIGNED KARL COMPTON CHAIRMAN ADMIRAL No 2 EILEOSITBIZ No ORCHARTROON No A SPECIALHandle only 1 accordan e with Top Secret instructions contained in Article 76 Navy Regulationst COPY N0 OPNAV 19 78