SECTION 13 ROLL.UP—POST.SANDSTONE REQUXREMENT5 Plans for roll-up of Operation Sandstone were established on a progressive basis early in the planning stage. Field Order No. 1, dated 14 November 1947, took cognizance of the roil-up requirements that later would be imposed on the Task Force and directed attention to the need to provide progressive plans there for. Field Order No. 2, dated 8 March 1948, established a framework of plans and procedures upon which the subordinate units of the Task Force based their roll-up activities. During the period of approximately four months between the issuance of the two field orders, the staff of the Joint Task Force gave consideration to the problems of closing out the operation concurrently with plans for the execution of the Task Force’s mission in Operation Sandstone. The Chairman of the Atomic Energy Comission, Mr. David E. Lilienthal, on December 1947, in a memorandum to the Joint Chiefs of Staff, reaffirmed the view of the AEC that a proving ground would be required so long as atomic weapons are being developed and produced. Mr. Lilienthal stated that a two-year interval between tests may meet the more urgent requirements of proof-testing. He suggested in this memorandum that the Commander, Joint Task Force Seven, and the staff of the Atomic Energy Commission work out the details as to the degree of permanence of th~ proving ground and the disposition of property. On 20 February 1947, the Joint Chiefs of Staff directed the Commander, Joint Task Force Seven, to implement this latter suggestion. As a result of this, the Task Force responsibilities for closing out the operation were extended to encompass the following: 1. To place the proving ground in a standby condition and in a state of preservation sufficient to permit minimum maintenance and minimum rehabilitation upon return of a large body of personnel within a two-year period. 2. To devise plans for the maintenance of adequate security against the possibility of a foreign agent entering the area and securing information on fissionable materials residual from the tests. Additionally, roll-up plans had to provide for the disposition of property, including decision as to which equipment could profitably be left at the proving ground and that which could more profitably be returned to another locality. This consideration extended to the installations at Kwaj alein as well. During December 1947, and January 1948, General Hull anticipated the Post-Sandstone requirements for a permanent proving ground and directed that the matter be made a continuing study. General Barker, the Assistant Chief of Staff, J-3, early in January prepared a standby plan for the proving ground, based on assumptions as to its permanence. Prior to the time the Joint Chiefs of Staff directed that details as to the permanence of the proving ground be worked out between the Commander, Joint Task Force Seven and the AEC staff, a roll-up board was organiz~d within the Task Force. Headed by Lt. Col. L. J. Lincoln, U. S. Army, this board included representatives of the AEC and of the armed services. On the basis of reconnaissance at the forward area by members of this board, 141