On the basis of recommendations contained in the report of the laboratory findings and result of the tests performed on the various samples brought back by the Reconnaissance Party, foundations were de signed for 4 maximum soil bearing value of 3000 pounds per square foot where founded on sand, and 5000 pounds per square foot where founded on coral rock, In view of the fact that the accomplishment of design within these limits presented no unusual problem, it was determined to be, in the best interests of economy, unnecessary to carry out an exhaustive drilling and soil investigations program covering all of the islands proposed for inclusion in the Proving Ground Complex. Late in 1949, in connection with the problem of rotating and extending the airstrip on Eniwetok Island, the H&N Engineering Division requested test borings on the southern extension of the existing strip. These borings revealed coral rock at depths of seven to eight feet below the surface of the airstrip, covered by a mixture of ruck, organic silt, and fiberous material which had been used to fill in the area at some time in the past. At approximately the same time, the AEC requested that exploratory probing be accomplished on Engebi Island to prove, or disprove, the rumored existence of a large subsurface cavern near the center of the island, The area to be explored, and the spacing of the test holes, was specified and a further drilling program was anticipated which led to the requisitioning of wagon drills at this time. Pending the arrival of such equipment, probings were carried out by improvised methods which, although disclosing strata of varying resistance attributable either to degrees of water saturation or to granular compaction, indicated a hard, coral conglomerate at six to nine feet below grade. No gross voids were disclosed and these probings were, therefore, considered to have served the desired purpose, Samples of coral aggregate and sand were obtained during the course of these investigations and shipped to the Atomic Energy Commission for further analyses by interested agencies. The adequacy of the original soils investigations for all structures for which Holmes & Narver had design responsibility continued until the late spring of 1950 when it was decided that for one or more experiments a rather complex tower would be required, The criteria for design included that the tower be 200 feet high and capable of supporting 200 tons in the cab at the top. Furthermore, in conjunction with the load just mentioned, a lead, or lead and limonite concrete column more than three feet in diameter and 200 feet high would be required, together with a limonite concrete blockhouse at the base of the tower characterized by walls four feet thick and a floor and roof each five feet thick. The total estimated weight upon the foundation was in the neighborhood of 2100 tons and the design criteria specified a maximum deflection at the top of the tower of not more than one inch. To permit designs which would satisfy these criteria, the original samples and investigation of bearing values were not considered to by adequate and, on July 1, 1950, AEC approval was requested for the employment of consultants to carry out further investigations now required, At about this same time, discussions concerning the foundations for Army Structure 3.1.1 were going on, in view of the concern expressed in some quarters on this subject. Permis- sion was therefore requested and granted for the Holmes & Narver consultant 5-81