CHAPTER II, SECTION 2 Figure 2-18. Trailer Mounted Drills », * Soy Figure 2-19. Batch Plant - Nan Main batch plant locations were determined by the quantity of concrete required at each site. Main plants were set up on sites Elmer, Fred, Yvonne, Ursula, Gene, Janet, Nan, Tare, and Fox. Small concrete requirements were met by precasting where practicable or through the use of small mixers. The time-consuming operation of hand-loading cement into the main batch plant hopper was eliminated by using a conveyor belt that dropped the racks of cement on a short roller above the mixing box. A sharp knife projecting above the rollers, automatically ripped open the sacks and the cement then passed through a large mesh screen into the hopper, after which the sacks were retrieved. Figure 2-21. Grading and Rolling - Airfield This reduced the number of personnel that operated the cement batcher from six to three and also eliminated the need of a special platform for the men and cement. Unusual care was necessary in pouring con- crete for those structures designed with great amounts of reinforcing steel. Physical characteristics of the concrete used and the inspection of construction have been discussed under Tests and Inspection, Section 1, of this Chapter. The concrete poured monthly in Eniwetok and Bikini Atolls is shown in Figure 2-25. Approximately 205,000 bags of cement and 2,700 tons of reinforcing steel of various sizes were required for Operation REDWING. Page 2-19