Mining Publication: Technology News 470 - Analysis of Hangups and Structural Failure in Underground Mine Ore Passes

Analysis of Mine Safety and Health Administration (MSHA) accident statistics has identified ore pass hazards as a significant safety problem in underground metal. mines in the United States. Recent ore pass failures have underlined the lack of ore pass design methods and standards available to both MSHA and mine engineers. Injury and fatality data for the 20-year period between 1975 and 1995 show that nearly 75% of the injuries were directly or indirectly related to pulling or freeing ore pass chutes, the use of hand tools, falls of broken rock, and structural failures of chutes of gates and ore pass walls. Risk assessment methods, such as fault tree analysis (FTA), revealed the most probably causes of ore pass failures, assisted in defining research priorities, and allowed analyses of the chutes of malfunctioning ore passes. Important structural design factors are the static and dynamic loads that ore pass chutes and gates must withstand. Functional design factors may involve consideration of malfunctions in material flow, such as hang-ups, piping, and water inundations.