Summary:
The Mine has access to six coal seams that are stacked underground horizontally. The seams are identified alphabetically—A through F—with the A Seam being the deepest seam. The F Seam is closest to the surface and several hundred feet underground. The seams are separated by layers of shale, siltstone, and sandstone that vary in thickness from between 15 and 250 feet.
The mine has been developed into the F, E, and B coal seams with current production taking place in the E coal seam. The E coal seam averages about 114 inches in height. The seam is a four-to-five-degree pitch to the Northwest with a maximum overburden of about 1600 feet. The B seam is being developed for mining, and F seam is used for travelways.
Summary:
West Elk is an underground mining complex. The West Elk mining complex extracts thermal coal from the E seam. The West Elk mining complex consisting of one longwall and supported by continuous miner sections, a preparation plant and a loadout facility.
As of March 2025, the mine has been developed into the F, E, and B coal seams with production taking place in the E coal seam. The E coal seam averages about 114 inches in height. The seam is a four-to-five-degree pitch to the Northwest with a maximum overburden of about 1600 feet. The West Elk longwall mine in Colorado experienced a period of transition associated with its move to the B Seam in the fourth quarter of 2025.
There are eleven surface openings, four intake entries, one main fan exhaust entry, three blowing fans, one belt entry, one escape hoist shaft entry, and one main haulage entry from the F seam. The mine has six portals leading into the F seam portion of the mine. The mine has a total of four ventilation shafts that supply ventilation into the B seam and E seam portions of the mine. One ventilation shaft provides exhausting ventilation to the E seam. The average seam thickness is 10 feet.
Longwall mining involves using a mechanical shearer to extract coal from long rectangular blocks of medium to thick seams. Ultimate seam recovery using longwall mining techniques can exceed 75%. In longwall mining, continuous miners are used to develop access to these long rectangular coal blocks. Hydraulically powered supports temporarily hold up the roof of the mine while a rotating drum mechanically advances across the face of the coal seam, cutting the coal from the face. Chain conveyors then move the loosened coal to an underground mine conveyor system for delivery to the surface. Once coal is extracted from an area, the roof is allowed to collapse in a controlled fashion behind the hydraulic roof supports. Depending on the depth of the cover, the seam thickness and overlying geology, the collapse of the roof can cause surface subsidence.
Longwall Specifications:
• Seam - B;
• Seam height - 108-168 inches;
• Cutting height - 108-156 inches;
• Panel width - 1,100 ft;
• Panel length - 3,000-10,000 ft;
• Overburden - 400-1,400 ft;
• No. of gate entries - 3;
• Depth of cut - 42 inches;
• Haulage system - Jumbotrac;
• Roof support yield (tons) - HBT 1,224;
• Roof support controls (type) - HBT PMC-R;
• Face conveyor type (strand, motors) - HBT, 48-mm chain, twin strand inboard, three 1,650-hp motors;
• Face conveyor drives - HBT CST;
• Face conveyor width/speed - 1,188 mm/371 fpm;
• Stageloader type, width, speed - HBT, 1,388 mm, 464 fpm;
• Crusher - HBT;
• Electrical controls - Service Machine;
• Voltage to face - 4,160.
Room and pillar mining is effective for small blocks of thin coal seams. In room and pillar mining, a network of rooms is cut into the coal seam, leaving a series of pillars of coal to support the roof of the mine. Continuous miners are used to cut the coal and shuttle cars are used to transport the coal to a conveyor belt for further transportation to the surface. The pillars generated as part of this mining method can constitute up to 40% of the total coal in a seam. Higher seam recovery rates can be achieved if retreat mining is used. In retreat mining, coal is mined from the pillars as workers retreat. As retreat mining occurs, the roof is allowed to collapse in a controlled fashion.
The miners work 12-hour shifts, days and nights, 7 days a week. The mine has an average production of about 12,757 tons per day using continuous mining machines, one retreating high voltage longwall, and a continuous mining pillar section. On the continuous mining machine section, coal is transported from the face by diesel Ram Cars and then to the surface by conveyor belts. On the longwall section, coal is transported from the face conveyor directly on the conveyor belt to the surface. On the continuous mining machine pillar section coal is transported from the miner by diesel Ram Cars and then to the surface by conveyor belts.
Mining is underway the blocks of coal are about 75 feet wide X 112 feet long, starting at 28 Crosscut to the current mining location 25 Crosscut, then outby to 23 Crosscut where the blocks are longer, about 75 feet wide X 199 feet long to 19 Crosscut. The feeder and conveyor belt start at 3 Entry 22 Crosscut and the belt travels 3 Entry outby. Entries 4,5,6 and 7 are intake air courses, Entry 3 is the beltline, and Entries 2 and 1 are return air courses. Sunset Mains South has 6 seals between 30-31 Crosscut sealing all air courses inby. Pillar mining at 7 Entry, 25 Crosscut with Continuous miner (c/n9) and Mobile Roof Supports MRS-5 and MRS-6.