Laserfiche WebLink
r. _ e <br /> <br />STATE OF COLORADO <br />DIVISION Of MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman 81., Room 215 <br />Denver, CO 80203 <br />Phone: f3031 866-3567 <br />FAX: 1303) 832-8106 <br />DATE: November 17, 1992 <br />TO: Steve Wathen <br />FROM: Carl Moua <br />RE: Colowyo Coal Mine; C-S1-019 <br />~MR-22: Blasting Sketches and Blasting Reports <br />OF ep(O <br />N~°;; b <br />0 <br />~• <br />~ rB ]6 <br />Rny Romer <br />Governor <br />Michael B Long <br />Division Dirxior <br />The following ie my opinion concerning the appropriateness of allowing Colowyo <br />to substitute a blasting report with keyed symbols for individual blasting <br />sketches. <br />The purpose of a blasting report is allow the Division to independently calculate <br />the amount of exploaivea firing during any 8 millisecond delay. In order to <br />accomplish this, the Division needs to know the following specifics for each <br />blast: <br />- type of blast <br />- point of initiation <br />- amount. of surface delay between each charge <br />- amount of depth delay for each charge <br />- amount of explosive in each charge <br />- number of charges <br />- manner in which charges are laid out and the order of firing <br />It is the Division's responsibility to be able to figure the amount of exploaivea <br />used per 8 millisecond delay independent from the operator. Since the revised <br />blasting record submitted by Colowyo simply states the number of charges per <br />delay and the amount of explosives per charge, independent verification ie <br />difficult or impossible. <br />Independent verification can only be accomplished from a sketch, since the above <br />specifics may change with each blast. In my opinion, Colowyo should be required <br />to have a sketch for each blast as specified in Rule 4.08.5 (7). <br />M:\COAL\SFW\COLOWYO\MRBLAST.22 <br />