DESIGN Many of the planning studies, briefly mentioned above, contributed to the engineering or design of facilities ultimately constructed at the In addition, a number of special studies were carried Proving Ground. out on specific design problems, of which the examples given in the following paragraphs are illustrative. The initial design study assigned to Holmes & Narver was required in connection with the submission of recommendations on and designs of zero towers, The basic criteria for the towers included a requirement that the mass of steel employed should be minimized, Analysis of the problem indicated that, if a guyed, three-legged tower could be utilized, a significant reduction in the mass of steel required for a given height could be realized in comparison to a free-standing, four-legged tower, As a corollary, a higher tower could be provided in the threelegged design in which the mass of steel required would still be within tolerance limits, and the added height would be useful for scientific purposes, In connection with the dehumidification and air conditioning of various buildings, special studies were carried out directed towards the determination of the most suitable dehumidification equipment and vapor sealing materials, One of the most interesting problems encountered in the course of design work arose out of consideration of the extremely corrosive atmospheric conditions at the Jobsite and the fact that salt water was being used for many purposes. Thus, corrosion studies and others directed towards the elimination of electrolytic action were required, For example, in connection with the choice of clad aluminum sheathing for all semi~permanent buildings, extensive laboratory testing was required to determine the corrosion resistance of the materials involved. This same consideration preceded the design of many other prefabricated items shipped to the Jobsite. During the course of the Project, the many revisions in population estimates, established the necessity for re-examination and re-analysis of housing availability, power generation capacities, and water system capacities, Thus, for example, on September 15, 1950, a report on power and water facilities at Eniwetok and Parry Islands was prepared and subsequently transmitted to the AEC, Likewise, a new analysis of warehousing and food storage facilities was deemed appropriate and was accomplished. Other design studies prepared in the course of the project related to such subjects as the preparation of high strength coral concretes, design mixes for limonite and limonite-steel-aggregate concretes, paving materials and mixes and radio back-up systems, 15~2