Proper scaling is necessary for safe operation during any underground mining activity. This need is documented in the mandatory regulations for scaling found in 30 CFR 57. In many U.S. mines operating today, scaling is accomplished by manually barring-down the loose material from around the mine opening. Barring-down requires a great deal of physical strength, endurance, and judgment to safely scale an underground opening. In addition to being one of the most physically demanding activities underground, it is one of the most dangerous. As recent accident statistics indicate, a large percentage of the “fall of ground” accidents and fatalities is directly related to manual scaling. Consequently, safer scaling practices are needed within the mining industry.
In addition to the definite safety hazard, adverse economic factors are also associated with manual scaling. Lost-time accidents and fatalities represent a significant direct cost in terms of the loss of skilled miners and a more indirect cost in terms of increased premiums on Workman’s Compensation insurance. Despite the recent trend toward mechanization in underground mining systems, scaling remains primarily a manual operation. Further, it can be a very time- and labor-consuming process. Hence, as labor costs increase, the cost of scaling using current practice will