- QP IAl COpy NO gEeW _IIiUIl ' ClnrNTIH J C S 1552 5GU ut - - -15 t SPECIAL DISTRIBUTION 22 December 1945_ Pages 15 - t P 32 lncl JOINT CHIEFS OF STAFF TESTS OF THE EFFECTS OF ATOMIC EXPLOSIVES Reference J C S 1552 Series Report by the Joint Staff Planners • THE PROBLEM 1 To reco nend the general requirements scope and means of implementation of tests to deternune the effect of a tomlC explosives against mllitary targets and naval vessels FACTS BF RING ON THE PROBLEIVl 2 a In J C S 1490 3 the Comrfianding General Army Ai r Forces proposed that the remnants of the Japanese fleet be preserve for experimental purposes with all types 6f weapons including primarlly the atomic bomb b In J C S 1552 the Chief of Naval Operations COh- firmed the advisability of conducting tests using the atomiC bomb against naval combatant vessels and suggested that studies be initiated to determine the scope of these tests for the purpose of making recolTh 'Tlendations to the President DISTRIBUTION Admiral Adml ral General General General Admiral General Admiral General Leahy Nimi tz _ Eisenhower Arnold Handy Edvlards Hull Conolly Norstad COpy NO COpy NO 1 3 2 4 8 9 10 11 12 6 5 7 Admiral Blandy Adml ral Gardner Genex'al Cabell General Lincoln Captaln Campbell Secy JCS Secy JSSC Secy JPS General Groves 13 14 15 16 17 18 19 20 21 I - The Secretary of war and the Secretary of the Navy on 10 December 1945 after approval by the President made public announcement of the fact that joint tests were to be undertaken to determine the effect of the atomic bomb against naval vessels I d In approving J C S 1552 15 as amended the Joint Chiefs of Staff directed that the Joint Staff Planners in consultation With the Officer in Charge of the Atomic Bomb Project and members of the Military Advisory Board to the Officer in Charge of the Atomic Bomb Project 1 Prepare as a matter of priority an outline of the type of tests to be conducted the-general require4 ments and the desired informatiOn _ 2 Recommend the agency to be selected for the implementation of these tests 3 Draft a directive to the implementing agency 4 Prepare such of the above as is appropriate for submission to the President for approval DISCUSSION 5 See Appendix page 28 4 Early determination of the full effects of atomic ex plosives against naval vessels and other military targets as practicable in connection therewith is essential in order to appraise strategic implications of the application of atomic energy and to make such readjustments in the military program of the United States as may be indicated to assure best con tinuing provisions for national security 5 It is recommended that the Joint Chiefs of Staff a -Approve in principle the plan set forth in Appendix page 25 showing the type of atomic test to be conducted general requirements and desired information DECLASSIFIED - I Authority L00 3 h Agree that the operation be conducted by a joint task force operating under the Joint Chiefs of Staff with a task force commander appointed by them and assisted by a staff composed of Army and Navy personnel and civilian scientists Full support including procurement of addi- tional funds if required should be furnished by agencies of the War and Navy Departments including the Manhattan District In addition there will be constituted an evalu ation board or committee_composed of representatives from the Army Navy the Manhattan Districts and civilian life The principal function of this board or committee would be- to evaluate the results of the test for the-Joint Chiefs of Staff It would not constitute a part of the joint task force It would be available for advice to the_task force commander during preparations for the tests g3 Appoint immediately an officer charged with the mission of initiating at once plans and arrangements per taining to the technical aspects of the test this officer- to report to the Commanding General Manhattan District pending appointment of the task force commander and assump 'tion of responsibility by him d TransMit this report and the attached memorandum requesting Presidential approval to proceed with the tests to the Secretary of war and the Secretary of the Navy Appendix l8 e Issue the directive in Appendix page 21 after approval of the test is obtained from the President _implicetions_of the advent of the atomic bomb These tes' Authority 90 3 I sent TO APPENDIX Ah MEMORANDUM FOR Term gangrene Feel res sneerer OF ME AND SECRETARY OF THE NAVY -The Joint Chiefs of Steff have informed us thet they con sider an early determination of the effects of atomic explo -sives against navel vessels_essentiel to evaluate the strategic GTE necessary in order to determine among other things the conse quences of this powerful eeriel weapon with n Spect to the sizes composition and employment of the armed forces and U2 H4 iould particularly facilitate en analysis of future_novnl - V design and tecticsw They have recommended conducting tests against selected novel vessels which provide good representation of modern con 'struction'of combatant end merchant types The ships selected as targets be chosen from surplus vessels of the_Americen Navy and possibly some vessels which heVe been allocated to the Unrted States from the former fleets of Germany and Jepen Types of tests under consideration are on air burst surfece -eXplosion and or an underwater explosion ln eech ceSe ves- sels will be arranged at varying distances from the point of detonation to obtain grodetion of fron mox1num to negligible Full advantage Will be taken of the opportunity to obtain information With regard to other military targets IDeteiled plans must await further study The Joint-Chiefs of Staff consider and we agree the the tests can best be conducted by a joint teshforce opersting under their direction and with the-support of the Wor_end Navy Departments including the Manhattan District The test force commander will be assisted by a staff composed of Army U1 and Navy personnel and civilian scientist if f x hinnv n I Authority 00 L3 a few 1 ggi zk There be organized to evaluate the results of the test a'boerd or committee composed of representatlves from civilian life and from the Army Navy and the Manhatten_D1s trict Th1s board or committee will be responsible directly to the Joint Chiefs of Staffa The program calls for the expenditure of only two or three bombs but it must be remembered that only three bombs have been used t3 date and there is a possibility of mechan ical or other failure which may require the use of further bombs to accomplish the purposes of the test If you approve we will so inform the Joint-Chiefs of Staff in order that-they may designate a suitable task force commander Appropriate directives will be issued to preceed with preparetions for the test You will be kept informed of significant developments DECLASSIFIED Authority L00 3 I APPENDIX is A DIRECTIVE TO COMMANDER OF JOINT TASK FORCE FOR TESTS OF ATOMIC EXPLOSIVES It By direction of the President you are designated come mander of a task force under the Joint Chiefs of Staff for the purpose of conducting tests for the determination of the effects of atomic explosives against naval vessels in order to appraise the strategic implications of the application of atomic bombs including the results on naval design and tactics You will organize a joint staff With adequate representation of land sea and air forces will include civilian tists in your organization 2 The general requirements of the test Will be to deterw mine the effects of atomic explosives against ships selected to give good representation of construction of modern naval and merchant vessels suitably disposed to give a gradation of damage from maXimumto minimum It is desired to include in the tests both air detonation and underwater detonation if the latter is considered feasible Tests should be So arra ged as to take advantage of opportunities to obtain the effects of atomic explosives against ground and air targets and to acquire scientific data of general value if this is practicable 7 You are authorized to deal directly with agencies of the War and Navy Departments in all matters relating to the preparation for and the conduct of these tests including direct access to the Manhattan Districtlr Usual service lines will be available for administrative and logistic support of forces assigned to the project DECLASSIFIED Authority Wm mun artist 4 The Joint Chiefs of Staff will appoint as a separate agency directly responsible to them an evaluation board committee for the express purpose of evaluating the results Of the tests This board will be available to you for advice during the preparation of the tests 'Appropriate sections of your orga ization will collaborate with this board as neces sary and you will provide it with all necessary facilities it may require to fulfill its functions 5 You Will prepare plans for the test including selection of a suitable-site which Will permit accomplishment of the tests With acceptable risk and minimum Your plans for the operation and final report will be submitted to the Joint Chiefs of Staff for their approval saga - DECLASSHHED g K Authority 00 3 APPENDIX iisu- 4 COMPILATION OF INFORMATION ON THE TESTS FOR THE ASSISTANCE OF THE IMPLEMENTING AGENCY l The Joint Staff Planners recommend that consideration be given to tests of the following types a With bomb detonated in air against ships of various types suitably disposed at proper distances to give a gradation of damage from negligible to maximum gigs priority E With bomb detonated at the_surface and or under water at moderate depth of the order of one hundred feet against ships of various types so disposed as to give a gradation of damage from negligible shock damage to maximum underwater damage resulting in sinking second priority 3 Same as except that bomb is detonated at a great depth below the surface of the water of the order of several thdusand feet Third priority 2 The general requirements recommended for these tests are a That the types of ships selected for targets be sufficient to give good representations of the various principal types of constructions used in modern warships and merchants and the number of ships used be the maximum practicable in order to gain the maximum useful information from each shot and to obtain general laws of relationship between damage and distance 9 Consistent with attainment of the primary objective of determination of the effect of atomic explosives against shipss all possible information be obtained applicable to the effect against personnel and military materiel of all types including installations and facilities on shore ECLASSIFIED Authority Ibo z tag That adequate preparation be made to insure that Ithe targets are in proper condition for the tests and that provision is made for adequate photography and other instrumentation and post-test examination to obtain information liSted below I g It is considered that the practical employment of this weapon is unavoidably linked with the operational factors involved_in its delivery placement on the target and detonation Therefore it is desirable that the conditions of the test approximate to the extent practic able without prejudice to the major objectives of the test actual combat conditions both with regard to delivery of the bomb and in the dispOsition and condition of targets Hence in determining the strategic implications of the atomic bomb consideration must be given to our ability to employ it so as to approach the_optimum desirable conditions 3 The objective of the tests should be to determine all practicable information along the following lines g Air Tests 1 Range at which targets of each type are rendered militarily ineffective by blast from detonation in air character of damage at other ranges 2 Range at which products of fission preclude operation of ship Range at Which seVere underwater damage occurs 4 Pressure time curves of blast at selected targets suitably spaced 5 Pressureutime curves of underwater shock at selected targets suitably spaced 6 Complete description with photographs of all damage Authority 0 3 u it Underwater Tests 1 Range at which targets of various types are sunk time required to sink in each case 2 Range at whichatargets of various types are rendered inoperable by underwater shock damage 3 -Range at which products of fission preclude Operation of ship 4 Pressure time curves of underwater shock at selected targets jsuitably spaced 5 Descriptionof damage as complete as practicable by following means I I Divers inspection of sunken ships where depth of water permits and of damaged ships as necessary Inspection of damaged ships above water- and internally Final inspection in-drydock of certain ships selected to give good soverage of typical cases E For all tests 1 Adequate instrumentation of various types to determine total energy release_of bomb and other characteristics of bomb performance 2 Determination of any effects of the detonation on fuel gasoline munitions and other expendable material essential to military operation of the ship 3 Estimation of effects on personnel on shipboard in various stations above and below deck 4 Any information which can be obtained on the effect on amphibious operations of atomic explosions in the vicinity of a beachhead to include result of Such explosions on Landing craft deployed at the moment of landing Beach installations including temporary harbors piers roadways and beach dumps of lammunition food gasoline and transportation I Field communication equipment Lethal effect'on personnel in the open sheltered by light cover such as light decks of landing craft in foxholes and sheltered in heavy cover such as heavy armored decks or under ground shelters Effect of residual radio actiVity on the operation of a beachhead 5 Any information which-can be obtained on the effect of atomic explosions considered both from the offensive and the defensive aspect on the follow- a ing types of targets a to include blast burn and radiation hazards and effects g Buildings of modern reenforced construction in order to_establish data from which blast pressure and impulses heat radiation data earth shock and residual radio activity effects can be generally determined 0 Above ground and under ground shelters and fortifications - Aircraft airdromes their revetments and other facilities including supplies Road nets and bridges Harbors and canals including tidal wave effects water and earth shock on locks and dams and effects of residual radio activity particularly in the water Storage installations including effect on bulk storage of gasoline ammunition foods and storage of atom bombs 96 Appendix Water supply installations water storage and sources of potable water Range of and residual effect on reception transmission and-propagation of radio and radar signals Long term effects on weather Photographic materials 6 Any information which can be obtained on the- effect of atomic explOsions on normal military targets in the field to include Terrain in so far as it limits effect of explosions Lethal radii of bursts of various heights on 'flat terrain against personnel in the open person nel in slit trenches personnel in vehicles person- MCHEB nel in armored vehicles Residual radio activity effects on personnel in varying degrees of shelter described above - i Length of-time after explosions at various 3 heights required before armored vehioles personnel in unarmored vehicles personnel on foot can safely pass through the area affected sg Effect of expOsure to explosion and resultant 1 radio activity upon-metals of tanks vehicles and armament upon ignition systems fuel ammunition rubber tracks and tires -codling systems oils and gases in recoil and recuperation systems electric cables field communication equipment etc g Partial data on many of the items listed in the paragraph above can be obtained by arrangements such as utilizing decks of ships or a nearby island if the test is conducted in the vicinity of one or both It is appar ent hovever that much of the information desired may be incomplete or in certain instances may not be attainable from the test contemplated u 3 3 Authority in DISCUSSION 1 It is desirable to determine the detailed effects of atomic explosives on all types of targets in the air on then ground Under the ground on the sea and under the sea Seme- data are already available from the initial tests in New Mexico and from examinations of the areas in_Japan which were affected by the two bombs dropped during the war This- information can be accepted for the time being as_establishingi effects of the atomic bomb against ground targets from an air burst The effect of underground burst of atomic explosives against ground targets may be approximated by detonating the proper amount of conventional high explosives underground There is an urgent need to determine the effects from air burst and underwater explosion of the bomb against naval vessels Analysis of available data and that to be obtained from the tests recommended herein should provide a basis for estimating effects of atomic explosions against targets in the air Representatives of the Navy'Department suggest that tests should be conducted against selected ship targets which provide good representation of the principal types of con i struction used in modern warships and merchant vessels thhe numbers of ships used for the tests should be the maximum practicable in order to gain the greatest useful information from each burst 3 The Navy Department has selected a group of combatant and merchant vessels of representative types which will be available for destruction in connection with scientific investigations Annex page Vessels for the test of atomic explosives can be chosen from this group The_assembly Authority 3 'location in the western Pacific will be probable Ifurnishing the project full support -Jcs 1552 5_ A movement stationing and the logistic support of target vessels will be an operation of considerable magnitude Ships employed for the tests will be in sound condition _3 -4 The Officer in Charge of the Manhattan District has stated that there probably will be three atomic bombs available for the test during the Spring of 1946 g It appears that withI appropriate priority it will be possible to assemble necessary equipment for the control of the-test and for the instrumenta tion and measurement of results Scientists and skilled technicians in this field can be obtained if the test is con ducted prior to 1 July 1946 These personnel are_anxious to return to their civilian pursuits and retention of their services beyond that date will be difficult 5 Detailed planning for the tests will require extensive study not only from the scientific but also from operational standpoint IThe hazards involved are not only great but many are of an unknown magnitude and character ' While the feasi bility of conducting the test employing an air burst is assured and the risk of an underwater burst is probably acceptable detailed arrangements of the former and a practical solution of the latter remain for future study Information is not yet available which Willpermit definite selection of a site for the test HoWever fundamental requirements indicate that a The over-all complexity of the problem makes necessary early initiation of idetailed plans and designation of an implementing agency 6 It is considered that the test can best be Conducted by a joint task force operating directly under the Joint Chiefs of Staff with necessary agencies of the War and Navy Departments The importance of the test warrants high priority in alloCation of funds personnel 29 Appendix resources Operations involved in the test ere gets major cetegorics novel and solentific The magnitude of the tosk_from the navel stondpoint and the vital bearing of the results on novel design and tactics are strong arguments thet the tee force should he's flog officer of the Navy With extensive operetionol esperience provided With n stuff comprising air ground and see elements and fully copohle of eccomplishing the non technicol planning and operation of the test On the other hend the experimentol nature of the onhg the rodiet on end other hazerds the extensive scientific reguirenents which must hornet from the resources of the Monhot ten District constitute strong arguments for the designation of the task force commander from-the Manhattan District or its successor very important end result of the conduct of the I 5 tests is cenfidence in end genera acceptance of the resul s I 4H 59 c u 9 eg by the many factions service soientific and politicalhove legitincte one Vitul interests in consequent dec1sions '2 -- it The choice of a commander and his staff should reflect these Authority requirements and guarantee the objectiVity in planning and implementing the tests The foot that the general plans for the tests and the evaluation of the results ere to be reviewed by the Joint Chiefs of Staff should contribute largely toward the attainment of this objective Consideretion might well be given at this tine to the cstobliShment of hoord to evaluate the strotegic implications of the test resul I 7 A joint staff comprising U of the ch Army end Arny Air Forces should he proVidcd the toe force commander end to facilitate evaluation of the results of the test the task force commander should have the ossistunCe of on evoluo 'tion'hoord Such board composed of officers of the_Nuvyi Army end Army Air Forces with one or more civilians appointed by the Secretary of Wur end the Secretary of the Navy Will he of value in establishing the dispossionote cherocter of the est for historical purposes ANNEX TO APPENDIX ztr ll VESSELS AVAILABLE FOR EXPLOSIVE TESTS l The following United States naval vessels are currently designated for explosive tests From among them may be selected ships of representative types 0f modern construction for tests of atomic explosives i BATTLESHIPS Arkansas New York Texas Nevada UKDLB Saratoga Ranger CRUISERS Authority Pensacola Salt Lake City EQLE A total of four 4 DESTROYERS 1500 ten A total of 29 ton A total of three 3 sansHMEs A total of tWenty-four 24 -AUXILIARIES LIBERTY HULL -A total of thirty A total_of thirty 30