+---------------------------------------------------+------------+ | | Number | | Blasting Notes: | of Sticks | | +------------+ | Heading: First Round: 6 sticks, 60% in each cut | | | hole, cut generally blasted twice | 36 to 72 | | Second Round: 3 side holes each side, | | | 5 sticks, 40% ea. | 30 | | Third Round: Rest of side holes and dry | | | holes, 5 sticks, 40% each | 40 | | Stub holes, say | 5 to 15 | | +------------+ | Total Sticks | 111 to 157 | | +------------+ | Total Pounds | 93 to 131 | | +------------+ | Sub-bench: 4 widening holes; 2 to 3 sticks, | | | each, 40% | 10 to 12 | | 6 down holes; 5 to 7 sticks, each, 40% | 30 to 42 | | Bench: 6 holes; 6 to 8 sticks each, 40% | 36 to 48 | | Taking up bottom, average, say | 15 | | +------------+ | Total Sticks | 91 to 117 | | +------------+ | Total Pounds | 76 to 97 | +---------------------------------------------------+------------+ [Illustration: Fig. 2. CROSS-SECTION, LONGITUDINAL SECTION, PLAN] Drilling Method, No. 2: Five drills in heading, mounted on three columns; the holes marked with a cross (X) were drilled with the drills on the center column. +--------------------------------------------------+ | Per Round | +---------+---------+---------+----------+---------+ | | Total | No. of | Pounds | | | | Depth | Cubic | of | Advance | | | Drilled | Yards | Dynamite | | +---------+---------+---------+----------+---------+ | Heading | 190-220 | 35-42 | 134-196 | 6½-8 | +---------+---------+---------+----------+---------+ | Bench | 110-130 | 55 | 79-106 | 4 | +---------+---------+---------+----------+---------+