Purchase Specifications were prepared and the Purchasing Department obtained bids for special items, such as diesel engine-generator sets, water distillation units, aluminum buildings, electrical switchgear, transformers, and many others, The Engineering Division analyzed the bids and if the value of the purchase was less than $50,000.00 instructed the Purchasing Department as to which bid to accept. If the purchase value exceeded $50,000.00, the Engineering Division made recommendations, after analysis, to the Director of Engineering and Construction, Santa Fe Operations Office, Los Alamos, and his approval was obtained before the purchase was made, | The Engineering Division anticipated its designs and, based upon experience and judgment, made estimates of needed quantities of all construction materials, such as lumber, cement, reinforcement steel,wire, pipe and fittings, electric conduit, outlets, switches, poles and plumbing fixtures. Requisitions were then prepared for approximately 75 per cent of the estimated total quantities needed, and this material was purchased in the usual wey and shipped to the Jobsite as a stockpile or warehouse stock to be drawn upon by the construction forces, This operation was carried out before the completion of working drawings and, in many cases, before any drawings had been started for the structures, If this had not been done, construction of any building could not have been started for from three to six months after the completion of drawings, for it would have taken that time to take off material lists, and procure, ship, and off-load the materials required to construct that particular building or facility. By the end of 1949, the experimental program began to take form. The first of a long series of instrument charts was developed and issued on December 13, 1949. Structures to be used in connection with experiments were designated as "stations" as distinguished from "buildings", the latter being the support structures such as living quarters, laboratories, administration buildings, mess halls, shops, warehouses, etc, On the first chart, five groups of Users and thirtyeight stations were listed. Between December 13, 1949, and test time in the spring of 1951, the number of Users grew from five to twenty- seven (as broken down on the instrumentation chart) ,+ and the number of stations had increased from 38 to 839, Also, the number of islands involved in the experiments continually increased, On December 13, 1949, all stations were planned for three islands (considering Aomon and Biijiri as one). Finally, there were scientific stations on 18 islands of the Atoll. Ag soon as survey data were obtained for the first experiment island, the development of location maps was started. The geographical location of each scientific station, as well as the distance and direction of each one from its "zero" tower (the towers upon which the weapons were to be detonated) was plotted, Every time a new station was added or the location of a station changed, the particular location 1 Cost Reporting requirements required a breakdown of Users into seventy-eight groups and subgroups.