SECTION III DESIGN GENERAL: The design of facilities for the proving ground is based on information relative to experimental operations furnished by J Division and which has been outlined in Section I of this Supplemental Report, information obtained by the reconnaissance party when the Atoll was visited in October, 198, and on economic considerations consistent with good engineering practice. It was noted when the party visited the site that there was rapid deterioration of many materials due to the extremely corrosive action of the combination of high humidity and salt spray. However it was noted that cer- tain alloys of aluminum seemed to resist this corrosive action extremely well whereas most other materials showed evidence of extreme deterioration. It was therefore determined that all buildings and structures which are to remain for a period of five years should be constructed of those alloys of aluminum which have been found to resist the corrosive action referredto above. As a result of studies made it was determined to use structure in which the principal members are stamped from sheet aluminum of proper gauge and thickness. The alloy used for these sheets is 4S Alclad and the extrusions used for door frames, girts, panel frames, etc., will be of the alloy known as 63-ST. These particular aluminum alloys are highly resistant to salt spray and high humidity as well as having the desired tensile strength. Detailed description of the building construction is in- cluded hereinafter. SURVEYS: Section II of the Reconnaissance Report, Pages 10 to 15 inclusive, describes the survey work that had been done at the Atoll prior to ll.