Surface exploration drilling usually produces both a rock core and a geophysical log as evidence of rock composition and defects. However, when the roof is drilled underground during bolting, operators rely on the roof bolters' interpretation of drilling cues to locate defects in the roof. With a success rate of only 55% in crack identification, the reliability of information provided by roof bolters may be in question. Roof bolters are typically trained on the job, with the training focused mostly on machine operation and the roof bolting cycle. Most new miners receive little training on roof geology and the nature of roof defects. The results reported here show that experience has only a limited benefit to improving roof crack identification. Based on conversations with engineers and employees at each of the study mines, it can be said that very few experienced roof bolters have ever been provided with evidence of the accuracy of their roof crack identification. As a result, they have no way to verify their ability to diagnose roof cracks. This limited experience is then passed on to new roof bolters, perpetuating a line of potential misinformation.
Accident-prevention; Coal-miners; Coal-mining; Coal-workers; Expert-review; Industrial-hazards; Industrial-hygiene; Injury-prevention; Miners; Mine-workers; Mining-equipment; Mining-industry; Safety-education; Safety-measures; Safety-practices; Safety-research; Training; Underground-miners; Underground-mining; Work-analysis; Work-organization; Workplace-studies