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<br />4. Please refer to the revised report. <br />5. The total weight of explosives was correct. <br />6. The remarks referred to the modified sketch. For <br />simplicity both sides of the report were reproduced on <br />the one page submitted to the Division. <br />Overburden Blast - November 20, 1992 <br />1. Refer to the discussion regarding the November 24, 1992 <br />shot. Based on the burn rate for detonation cord and a <br />spacing of 24 feet the maximum number of holes detonated <br />in 8 ms is 8 holes in a row. Since two rows could be <br />fired at one time the total in this case is 16 holes. <br />2. Using the maximum 16 holes per 8 ms period the pounds of <br />explosives per 8 ms period is 16 x 144 = 2304 pounds. <br />3. The total number of holes was 148. The shot was 9 wide <br />by 16 long with 4 additional holes in and delayed <br />separately on the end of the shot. <br />4. The total weight of explosives was correct. <br />Coal Blast - November 24. 1992 <br />1. Please refer to the revised report. The shot layout was <br />10 wide by 15 long with the exception that in some places <br />the edge of coal was uneven and the shot was only 9 holes <br />wide for an overall total of 140 holes. <br />2. Please see the revised report. The maximum holes per <br />delay was 140. <br />3 - 4. In terms of total pounds of powder used, coal shots are <br />small when compared to overburden shots. Also, there are <br />no surface delays to slow the shot down. With this in <br />mind even if all of the holes go off instantaneously <br />there is no chance that the shot can exceed the <br />requirements of Rule 4.08.4. It can therefore be assumed <br />that for coal shots, unless otherwise noted they are <br />"instantaneous" and all the explosive is fired. A <br />determination of maximum explosives used in a 8 ms period <br />is in this case an unnecessary exercise due to the <br />limited amount of explosives. <br />5. (The Division's number 6) The total weight of explosives <br />was 1980 pounds. <br />For the purpose of determining the pounds of explosive per <br />hole the information is obtained by dividing the total weight of <br />explosives used by the total number of holes. <br />