camp at Parry Island was expanded. self sufficient. Each camp was laid out to be Power, fresh and salt water systems, sewage dis- posal, and recreational, medical, and communication facilities were installed. The principal difficulties reported in Operation CASTLE appear to have been related te the scheduling of the pre-operational phases of construction. The remoteness of the site, and lead time neces-— sary for procurement and mobilization, the difficulty of effective distribution of men and equipment on widely dispersed areas, ard transport over considerable water separation; all contribute to an extended construction period. Yet, in the earlier phases of the pre-operational period, few criteria are firm except the end date, which, teing infiexible, demands careful planning. Detailed sched- ules based on firm scope are not possible until late in a program when they were often too late for effectiveness, and early sched- ules tend to be fragmentary. However, experience in the problems of GREENHOUSE and IVY has enabled the contractor increasingly to anticipate and evaluate missing factors, and thus make realistic forecast. The momentum of scientific progress makes most of the resulting engineering and construction problems inherent to the project. Although the operational phase was changed in scope as a result of the first detonation, the rapid solution of the problems which followed indicated that the existing procedural techniques and organizational set-up were functional and flexible enough to accommodate not only an orderly progression in the operation, but also radical changes in plans. 106