SZCTION IV DESIGN GENERAL: The design of facilities for the Proving Ground will be based on informa=tion relative to the experimental operation furnished by J Division, information obtained by our reconnaissance party when the Atoll was visited in October 1948 and on economic considerations consistant with good engineering practice. Materials. The condition of various materials was noted by the reconnais- sance party aml the findings are described in Section II of this Report. Be- cause of the rapid deterioration of many materials, when exposed to the extremely corrosive action of high humidity and salt spray, much thought has been given to the selection of materials of construction and the protection thereof. Planning. Planning will be based upon the program of two sets of experi- ments extending over a period of not more than five years, including construction and preparation for the tests. However, this policy is not to be con- strued as limiting the type of materials to a five year life, but rather that in justifying an expenditure only two sets of tests are to be considered. In the selection of materials and methods, utmost reliability is the most important factor to be considered. This subject has been discussed in greater de- tail in Section III of this Report. The number of people to be provided for and the location of the population has also been discussed in Section III. The planning and design of facili- ties, as described in this section, are based upon the above criteria, that is: (a) New facilities for 600 people are provided on Parry Island, (b) maintain or replace existing utilities on Eniwetok Island and provide the necessary housing and facilities for approximately 600 military personnel, including Air Force Iv-l