+---------------------------------------------------+------------+ | | Number | | Blasting Notes: | of Sticks | | +------------+ | Heading: First Round: 2 to 3 relieving holes | | | sprung, with 4 to 5 sticks each | 8 to 15 | | 8 cut holes, 7 sticks each | | | (sometimes shot twice) | 56 to 112 | | First side round, 6 holes, 6 sticks | | | each | 36 | | Widening and dry holes, 10 to 12 holes, | | | 6 sticks each | 60 to 72 | +---------------------------------------------------+------------+ | Total Sticks | 160 to 235 | +---------------------------------------------------+------------+ | Total Pounds | 134 to 196 | +---------------------------------------------------+------------+ | | | | Sub-bench: 4 widening holes, 4 to 5 sticks each, | | | 2 rounds | 32 to 40 | | 6 down holes, 5 to 7 sticks each, | | | 2 rounds | 60 to 84 | | | | | Bench: 4 down holes, 5 to 7 sticks each | 20 to 28 | | 6 to 8 lift holes, 5 to 6 sticks each | 30 to 48 | +---------------------------------------------------+------------+ | Total Sticks | 142 to 200 | +---------------------------------------------------+------------+ | Total Pounds | 118 to 167 | +---------------------------------------------------+------------+ [Illustration: Fig. 4. CROSS-SECTION, LONGITUDINAL SECTION, PLAN] Drilling Method No. 4: 8 drills on 4 columns used in heading. Bench taken off in one lift. Bottom taken up with lift holes. +--------------------------------------------------+ | Per Round | +---------+---------+---------+----------+---------+ | | Total | No. of | Pounds | | | | Depth | Cubic | of | Advance | | | Drilled | Yards | Dynamite | | +---------+---------+---------+----------+---------+ | Heading | 310-320 | 63-71 | 215-257 | 8-9 | +---------+---------+---------+----------+---------+ | Bench | 190-210 | 89-100 | 107-155 | 8-9 | +---------+---------+---------+----------+---------+