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JOHN F. ABEL,JR. <br /> MINING ENGINEER <br /> 310 LOOKOUT VIEW COURT <br /> t1 I/ GOLDEN.CO 60401 <br /> /� 'D �* �► �� 303-2794901 <br /> SY v��N FAX 27"163 <br /> May 28, 1994 <br /> Mr. Larry Perino <br /> �DSunnyside Gold Corp. <br /> P.O. Box 177 <br /> Silverton, CO 81433 <br /> Dear Larry: <br /> This is the letter report you requested concerning my May 23 . <br /> 1994 inspection of final preparations for filling the second <br /> (primary) B-Level/Brenneman bulkhead and my May 24, 1994 <br /> observations of the filling of that bulkhead. The second B-Level <br /> /Brenneman bulkhead was constructed as designed and filled in one <br /> continuous pour, without a single breakdown during filling. The <br /> bulkhead thickness between the form is 3 feet, the downstream <br /> tensile reinforcement consists of #10 bars on 12-inch centers <br /> (two-way) , the upstream temperature and shrinkage reinforcement is <br /> #6 bars on 12-inch centers, as detailed in my February 21, 1994 <br /> memo. The irregularities in the walls of the second B-Level/ <br /> Brenneman location are such that the bulkhead appears to have been <br /> notched into both ribs, the roof and the floor. This bulkhead <br /> appeared to have greater irregularity in the adjacent tunnel roof, <br /> ribs and floor than any of the preceding three bulkheads. The <br /> profiles provided indicate this observation is correct. <br /> At 8: 30 AM on Monday, May 23, 1994, I reached the second <br /> (primary) B-Level/Brenneman bulkhead location. At that time, the <br /> water collected within the form was being pumped out. The pumping <br /> operation and closure of the lower window into the form closed by <br /> 9: 00 AM. The crew attempted to start pumping about 10: 00 AM. The <br /> concrete pump failed after insertion of the slurry to slick the <br /> slickline and at the start of concrete mix pumping. After <br /> dismantling the concrete pump a partial plug of concrete from <br /> filling the first (secondary) bulkhead filling operation was found <br /> hidden in the gooseneck. The concrete plug was chiseled out, the <br /> pump reassembled and the slickline was cleared of the specified mix <br /> concrete at about 2: 30 PM. The slickline plugged again when the <br /> new mix concrete injected into the slickline separated <br /> approximately 80 feet down the 740-foot long slickline. The <br /> slickline was disassembled and cleared, the equipment cleaned of <br /> all concrete and the slickline reassembled by 5:30 PM. It was <br /> decided to start again Tuesday morning because of the lateness of <br /> the day and the problems already encountered. It was possible to <br /> terminate operations because no concrete had entered the bulkhead <br /> form. <br />