Waste Edge Suppport

Waste Edge Suppport 

an individual support that is used in broken working areas for roof control by means of artificial caving. It is placed at the boundary between the waste area and the area of the working face and is moved or raised as the excavation progresses.

There are three types of waste edge supports: organs, cluster supports, and chocks. An organ is composed of one or several straight rows of props, with spacing that does not exceed their diameter. A cluster support is composed of groups of three to ten props, with a distance of 2 to 10 m between clusters. Metal or wooden props are used for organs and cluster supports. Chocks are in the form of cages that are made up of props, beams, or rails; they are rectangular or, less commonly, triangular in shape. In the early 1970’s movable inflatable chocks were introduced in narrow, steep seams in the Donets Coal Basin. The Sputnik

Table 1. Technical characteristics of waste edge supports produced in the USSR
	Support
	Sputnik	OKUM
Width of seams served (m)......	0.55-1.8	0.47-2.0
Number of standard sizes ........	4	7
Initial thrust (tons)..........	47	2.0-2.5
Working strength (tons) .........	80	100-200
Weight of props (kg) .............	318–404	95-364

hydraulic waste edge support and friction props of the OKUM type are widely used in working faces with individual supports in the USSR. Table 1 shows the technical characteristics of these two types.

V. V. ZHUKOV