FIGURE 4-5 Average dust concentrations for U.S. longwall and continuous mining operations. SOURCE: Gillette et al., 1988; Ramani and Mutmansky, 2000.

One technological trend in the mining industry is the steady increase in the size of mining equipment. As the level of automation increases, large machines may be able to operate in a fully automated mode (Shuey, 1999). Larger equipment will certainly decrease individual exposures to hazardous conditions in the mine environment. However, they will also introduce new problems. For example, the increasing size of mobile mining machinery, particularly large hauling equipment, has increased the likelihood of accidents by decreasing all-around visibility for the operator. If the operator does not know his precise location in the mine, near a berm or where nearby objects, such as other miners and smaller equipment are, fatal and costly accidents can result. Technology that can alert equipment operators to the presence of obstructions (e.g., other equipment, berms, miners) and their relative distances would mitigate this problem. In addition to the extensive use of closed-circuit television, automatic control of the equipment, aided by onboard sensors and GPS monitors, could reduce these hazards.

Several mining systems (e.g., longwall systems in underground coal mining) are already highly automated. Semiautonomous and fully autonomous systems can result in higher levels of production and productivity, as well as better health and safety conditions. However, automated equipment, even remotely controlled equipment, can create new hazards. Because the number of automated systems in the mining industry is small, no extensive data on health and safety are available. However, it is known that automation has been responsible for a small number of mine accidents involving deaths and disabling injuries (NIOSH, 1999).

Automated equipment is also subject to unexpected or unplanned movements. Unique challenges presented by the mining environment to the designer and operator of automated equipment include the lack of precise knowledge of operating conditions, mostly because of variations in geology; a demanding operating environment exacerbated by extremely dusty, noisy, and vibrational conditions; specialized equipment design to meet the stringent