Narrow-Web Coal Mining

the extraction technology in which bulk coal on the working face is broken up by the working element of a stoping machine with a web as narrow as 0.8–1.0 m in a zone where coal has attained a moderate to high metamorphic rank under rock pressure.

Narrow-web coal mining is the main method for working gently sloping seams of various thicknesses and steep seams up to 2 m thick (1975). Narrow-web cutting-loading machines and plow units are used for stoping (seeCUTTING-LOADING MACHINE; PLOW UNIT, COAL). Narrow-web mining using a cutting-loading machine is universal in application; plow units are used in seams where the shear strength of the coal does not exceed 180 kilograms-force per sq cm and are especially efficient in the extraction of anthracites. Narrow-web coal mining made possible the development of powered support, the solution of the problem of integrated mechanization of heavy and labor-intensive processes on the working face, and the improvement of labor safety and concentration of operations. A record for narrow-web coal mining was set in the Maiskaia mine of the Rostovugol’ Production Association in April 1975, when 205,000 tons of anthracite was extracted from a longwall in 25 working days.

In 1975, narrow-web coal mining was used to extract 407 million tons of coal in the USSR, 85 percent of the total underground extraction. This included 225 million tons from fully mechanized stopes. Narrow-web coal mining is used in all the European countries.