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| Roof bolting in underground coal |
Background
Hazards arise from work environments and improperly designed workstations, equipment, or work methods. Mine work hazards include machine and human-body appendage collisions and operator errors. Tasks related to boom arm movement have a high degree of hazardous acts, and no data exist on safe speeds for booms operating close to workers in a confined work environment such as is found in underground mines. Incident investigation reports do not usually contain enough information to aid in studying this problem. Laboratory and field experiments with human subjects are not feasible because of safety and ethical issues.
Work-related musculoskeletal disorders (MSD) include awkward postures, repetitive and forceful motions, and excessive jarring and jolting. MSHA injury/incident data from 1993 to 2004 showed a total of 139,222 nonfatal lost time injuries. Repetitive MSD injuries composed 46% of the reported incidents and machinery and powered haulage composed 24%. Research is being conducted to assess and reduce the presence of underground mine work hazards to which the work environment, equipment, and performance of work contribute significantly to roof bolter operations. The fundamental issues being addressed are—What boom appendage speed(s) maximize the operators’ chances of escaping injuries while still allowing the operators to perform bolting functions effectively? What equipment design modifications are needed? What job-task-procedure changes are needed to reduce the risk of low back pain unique to the postural and lifting circumstances of roof bolters?
Potential Outcome
This research will suggest changes to roof bolting equipment that would have a direct impact on how the bolting task is performed. Guidelines and control interventions relating to boom speed ranges and procedural modifications of work postures to reduce injuries in the back and other parts of the body are expected. For example, in typical bolting activities, a tray is provided on which to stack material handled during the bolting operation. A guideline that suggests different locations for the materials tray has the potential to reduce low back stress by limiting bending, twisting, and lifting motions. Another example addresses the current situation in which operators can operate a boom arm’s speed and direction with one hand. A control intervention, such as redesigning the controls to require the operator to use two hands, has the potential to reduce injuries by keeping the body and hands clear of a moving boom arm. Most impacts resulting from modifications to roof bolting equipment are expected to take place by 2008.