The Leer Mine is a permitted underground longwall mine that extract coal from Lower Kittanning Seam and parting interval within the seam utilizing continuous miners to develop longwall panels to be mined using a longwall mining system.
There are six openings to the surface from the Leer Mine. These openings consist of the slope, dual intake and elevator shaft, return shaft, two bleeder shafts (District 5 and Sharp), and the Hardesty intake shaft.
Currently, there are three longwall development (gate road) continuous miner sections and one continuous miner supersection developing mains and production panels.
Projected continuous miner productivity is 105 feet per shift for gate road development and 144 feet per shift for the continuous miner supersections. Supersections are continuous miner sections with split ventilation that allows two continuous miners to operate simultaneously. Longwall projected productivity is typically 52 feet of retreat per day (26 feet per shift).
The longwall and continuous miner production crews work nine-hour shifts, two shifts per day, with hot seat change at the section face. A third shift per day for the longwall and continuous miner units is utilized for maintenance. Each continuous miner crew works a fiveand one-half day schedule (every other Saturday). There are four longwall crews that work a five days on, three days off schedule, rotating shifts every six weeks to provide longwall production seve ........
