which, by rotating motion, separate the coal from slate
Courtesy of U. S. Bureau of Mines
MODERN HEADFRAME, BINS AND TRESTLE
Of fireproof construction. Anthracite coal mine
American mine shafts are generally rectangular and are divided into two or more compartments. Where a shaft passes through water-bearing strata it must be provided with a tight lining, or “tubbing,” to prevent the mine from being flooded. All water that enters the mine collects in an excavation, or “sump,” at the bottom of the shaft, and must be pumped to the surface.
The method of working coal-seams most commonly practiced in this country is known as the “room-and-pillar” system. One or more tunnels, or “entries,” are first driven from the bottom of the shaft or the mouth of the drift. These are the main thoroughfares of the mine, and are usually provided with tracks, over which the mine cars are hauled by mules or by some other method of traction—locomotives, endless chains, etc. Secondary entries (“headings,” “butt entries,” etc.) branch off from the main entries. Finally, the work of extracting the coal consists of excavating open spaces, or “rooms,” adjoining the entries.
Courtesy of “Coal Age”
MODEL COAL BREAKER