sswv COPY NOJ Add $3 - 5 SPECIAL DISTRIBUTION JOINT CHIEFS OF DECISION AMENDING 1552 74 TEST OPERATION Note by the Secretaries On 23 August 1946 the Joint Chiefs of Staff Approved the recommendations in J C S 1552 74 subject to the amendment of Appendix and Annexes and thereto 2 Revised pages 207 208 20% and 210 incorporating the amendments are attached I DECLASSIFIED A J3 MOFARLAND C Joint Secretariat mm - 2 9 Asst 5 1 3 w 333 3 4 nun I A 4- es 2% 2pwi ik 1N 9% 5 $3 3'6 Oi ON A DISTRIBUTION COPY DISTRIBUTION COPY NO Adm Leehy l Adm Blendy l2 13 Adm Nimitz 3 6 Adm erdner l4 Gen Eisenhower 2 5 Gen Everest 15 Gem Speatz 4 Gen Lincoln 16 Gen Handy 7 Ceyt Campbell '17 Adm Ramsey 8 Seey JCS 18 Gen Norstad 9 Seey JSSC 19 Adm Sherman lG Seey JPS 20 'e 11 Gen Groves 21 I Gen We yl and Ll DECLASSHHED i 1 Authori MEMORANDUM FOR THE SECRETARY OF WAR AND THE SECRETARY OF THE NAVY l The Joint Chiefs of Staff consider that the conduct of Test to determine the effects on naval vessels of atomic explosives detonated at a great'depth below the water surface is not now advisable 2 It appears that the necessary utilization of technical personnel of the Los Alamos Laboratory in Tests and has already delayed the research and deVelOpment progress of the_Manhattan Project 5 A new military unit to handle the im portant is'being organized but will require a year's training before it will achieve satisfactory pro ficiency The conduct of Test would necessitate a further absence of these scientists from their research activities and would seriously interfere with the research progress which should instead be accelerated in the interest of our national' defense 3 In addition the President has recently directed economy measures be taken the effect of which tightens Significantly available funds and personnel 4 The Joint Chiefs of Staff Evaluation Board for the AtOmic Bomb Tests reports that Observations during the two tests have established the general types and range of effectiveness of air and shallow underwater atomic bomb bursts on naval vessels army materiel including a wide_Variety of Quartermaster stores and personnel From these observations and_fron instrumental data itiill new be possible to outline such changes not only in military and naval design but also in strategy and taCtics as r- 73J s laws ge sci aspo le A f DECLA S SUll U I Author ty NNt q q 3 _' J futuro events may indicate 11 Tho Joint Chiefs of Staff concur in this opinion and considor that tho major objoctives of the atomic bomb tests have boon achiovod from the information and data obtained in Tests ftA and liB 11 The additional data ox- pected from Test fC while important do not in their opinion warrant the effort and expense of conducting tho test in view of the considerations outlined above 5 The Joint Chiefs of Staff feel that the considerations outlined above arc overriding particularly in light of the present world situation and accordingly recommend that the plans and preparations for tho conduct of Test HC ft be indefinitely Postl- oned 6 It is requested that tho President bo informed of the foregoing recommendation and that he be requost8d to issue a suitable press release on the matter A proposed momorandum to the President and a suggested rress release are attachcd Annexes iiAlf and IiB to this Appendix A it DECLASSIFIED Authority ANNEX T0 APPENDIX A MEMORANDUM FOR THE PRESIDENT FROM THE SECRETARY OF WAR AND THE SECRETARY or THE NAVY The Joint Chiefs of Staff have informed us that theyl consider it advisable to cancel all plans and preparations for Atomic Bomb Test which they had considered holding early in 1947 to determine the effect on natal vessels 0f atomic explosives detonated at a great depth below the surface of the water It appears that the research and development progress of the Manhattan Project has been considerably retarded by the utilization of technical bersonnel of the Les Alamos Laboratory in Tests and B o No other similarly qualified personnel will be available in'less than a year The conduct of Test would therefore reqdire a further absence of these scientists from their research activities and would seriously interfere with the research program which should instead be accelerated in the interest of our national security The Joint Chiefs of Staff consider that the major objec tives of the atomic bomb tests have been attained through the information and data from Tests and and that the additional information expected from Test does not warrant the expenditure in money manpower and effort involved in the light of your recent economy directives and the present world situation Accordingly if you approve it is requested that you release the decision to postpone indefinitely preparations for Test A suggested release is attached Annex to Appendix LJ DECLASSIFIED Authori ANNEX TO APPENDIX A SUGGESTED PRESS RELEASE In View of the successfulcompletion of the first two atomic bomb tests of operation CROSSROADS and the information derived therefrom the Joint Chiefs of Staff have concluded that the third explosion Test Should not he conducted in the_near future _ The information obtained from Tests and together with the knowledge derived from the original experi mental test in New Mexico and from study of the results of the explosions in Hiroshima and Nagasaki will enable our scientific and military experts to mare a proper evaluation of the effects of this weagon The additional information of value expected to result from Test is such that the Joint Chiefs of Staff do not feel that completion of this test in the near future is justified The Joint Chiefs of Staff are extremely gratified by the conduct and results of the atomic bomb tests and consider the entire operation an unqualified success The invaluable assistance of the civilian scientific personnel and the inter-Service cooperation toward a common end were major factors in achieving this success DECLASSIFIED APPENDIX 0 7 MEMORANDUM BY THE COMMANDING GENERAL MANHATTAN ENGINEER DISTRICT 7 august 1946 l The Commander Joint Task Force One has asked the Joint Chiefs of Staff for final approval Of Test the deep water explosion of an atomic bomb against an array of naval vessels to be held in There are many reasons why such a test should not be conducted the more important of which are'set forth below Test of operation CROSSROADS definitely established nhat had been generally admitted previously viz that any capital ship can be destroyed by an atomic bomb by means of an air burst properly placed 3 Test has already established that an atomic bomb provides the same degree of energy transfer from bomb to water as from bomb to air After the successful completion 'of Test Test is nothing more than a test of deep water shock hydrodynamics chiefly pertaining to a ship's reaction to strong shock over a large portion of its sub surface area g Test if conducted at the preposed depth and with the target ships in a normal high seas fleet disposition should result in the sinking of_not more than one major ship While the shock damage will probably be greater in Test than in Test the important casualty producing radio activity hsnot expeCted to be present in such significant JCS l552 7A_ 212 - Appendix -DECLASSHHED i' Authori quantities in the target fleet but will be lost under water For this reason total personnel caSualties in the target fleet wOuld be expected to be considerably smaller as compared with Tests and 2 The Los Alamos Laboratory of the Manhattan Project will not have personnel for assembling the bomb who can be diverted to Test in 1947 or 1948 without seriously interfering with the research and development program A new military unit will soon be organised to handle the all important assembly functibn but this unit will need a year's training before it will reach satisfactory proficiency in the handling assembly and testing of atomic bombs In the event of'a national emergency we could assemble bombs on short notice this would necessitate drawing on former technical personnel 3 Our laboratory at Los Alamos will not be in a to handle the necessary instrumentation for Test The research and development program at our Los Alamos Laboratory has been delayed considerably by Operation CROSSROADS This program must be accelerated and nothing short_of a national emergency should be permitted to interfere with it 4 Finally I wish to call to the attention of the Joint Chiefs of Staff that even a single atomic bomb can be an extremely important factor in any military emergency It is imperative that nothing interfere with our concentration of effort on the atomic weapons stockpile which constitutes such an important element in our present national defense 1552 74 213 Annendix do APPENDIX FROM Commander Joint Task Force One FOR ACTION Chief of Naval Operations 160126 NCR 7916 17 August 1946 Your 141931 requests comment on recommendations of CG Manhattan District that Test be cancelledi My comment will cover three main points first results of Tests and as affecting second military'and national implications of recommendation of Manhattan thirdg over all technical and If political considerations E-J a Do not agree With Manhattan that point at issue - Tests and B was whether a Na asaki bomb can Sink a a s' capital ship Such an oversimplified question could have 3 v been answered in the affirmative a year ago without a test The real questions were much more complex and re1ated to the radii at which various kinds and degrees of damage would he suffered by various types or ships in order to determine required changes in design and in spacing of ships in port and at sea Mechanical damage in both Tests and was much more predictablexthan casualties to crews from radioactivity _ In fact the kind of radioactivity damage produced'in Test required additional extensive organizer tion to be ready to decontaminate ships and harbors after a subsurface burst meanwhile protecting the snrvivors and replacements against the lingering subtle hazard we now face in Bikini The one thonsand foot depth proposed tothe JOint Chiefs of Staff in my 06103l of 7 August for Test will very probably inflict lethal mechanical damage over a greater radius than obtained in Test and in addition a geyser of contaminated water will probably rise hundreds of feet above the surface Whether this geyser does rise nn Film in the Secretariat and if so what is its contamination its contaminating action are questions which can be answered only by an actual test The results of such a test in comparison with those of Test permit interpolation to obtain a depth for the optimum combination of mechanical and radioactive damage b There is a disturbing implication in the statement of co Manhattan to the effect that the Los Alamos Laboratory must devote itself so completely to new and militarily unproved developments that it cannot spare key personnel fan-r to carry out a Test in 194 or 19#8 In the first place it is unsound to have a military weapon as important as the atomic bomb oapable of asSembly only by a handful of g civilian scientists and technicians In the second place the best way to get this troublesome burden off the shoulders of the Los Alamos Laboratory is to have it participate fully and immediately while experienced people are still-available 'in the training in the United States of bomb'assembly and loading crews led by fully qualified officers and enlisted technicians The atomic bomb is complicated in design and requires officers with a new combination of knowledge back Iground and training but Rear Admiral Parsons who was in charge of ordnance design of the atomic bombs at Los Alamos estimates that with immediate and full cooperation of the Los Alamos Laboratory and the Manhattan District one of several naval officers could be trained within the next six months to take charge of field operations similar to those conducted in Albemarle and LSM 60 Current plans for Test eliminate most of the considerable instrumentation load carried by then Los Alamos Laboratory in Tests Another point in regard to Manhattan proposal is the following - It is reCOgnized that General Groves should not make major positive commitments for the future on the eve of turning_ i DECLASSIF IE over atomic energy development to'a civilian commission But by the same reasoning is it proper for him at this time to make a vital negative commitment probably binding the Commission and the nation throughout 1947 and 1948 It appears to the'Commander Joint Task Force Ones that such an important negative decision which if accepted might relegate the assembly and deliVery of the atomic home under combat conditions to the category 05 a lost art should he made only with the knowledge and concurrence of the presently legally responsible Atomic Energy Commission and the War and Navy Departments as represented by the- Military Liaison Committee after full review and personal knowledge of the facts g Viewed fresh from Bikini in August it appears that while we may already haveseen the most over all paralyzing delivery of the atomic bomb in the Testj the job we set out to do is unfinishedytechnically and in the minds- of the public If Test is cancelled it should he over the proteSt of the Navyc otherwise the Navy will be essentially accused of dodging the most decisive Test