Mine Rib Control in MSHA's Sights
The agency announced this is the focus of this year's Preventive Roof/Rib Outreach Program, PROP, because three rib fall deaths and three roof fall deaths occurred in 2010.
MSHA announced this year's Preventive Roof/Rib Outreach Program is focused on improved mine rib control because there were three rib fall fatalities and two roof falls that killed three miners last year and two more miners have died this year from underground rib failures.
"While recent trends have shown a decline in roof fall fatalities, the incidence of rib fall deaths has remained nearly constant," said Joe Main, assistant secretary of labor for mine safety and health. "Furthermore, approximately 100 miners are injured by rib falls every year, due in large part to the rise in mining heights underground."
Roof control in underground mines involves securing the top and sides of travel ways, or walls, which are called "ribs." MSHA said a detailed study of 22 of the 24 rib fall fatalities that have occurred since 1995 indicates the two greatest risk factors are mining height and depth of cover.
"Today, many mines are located in coal reserves that previously were avoided due to poor roof conditions," according to the agency. "These mines frequently are deeper and may have abandoned mines above and/or below them, which often exert additional stress on the roof and ribs. Other risk factors include multiple seam interactions, rock partings in the seam and retreat mining. Joints or slickenside (smooth-surfaced) geologic features that dismember the rib increase risk. Approximately three-quarters of rib fatality victims since 1995 were roof bolting and continuous mining machine operators."
"Over the past few decades, improvements in roof control technology such as new bolting systems, automated temporary roof support systems, use of cabs and canopies, and mobile roof supports have led to a significant reduction in roof/rib fall fatalities," said Main. "Through PROP, we hope to increase mine operators' awareness about the hazards and precautions necessary to prevent such accidents."
A "Coal Mine Rib Control for Mine Operators" brochure offers safety advice and tips for mine operators. Inspectors will deliver copies and other educational materials to underground mines, and mine operators will receive an alert on the hazards and actions needed to prevent accidents. This yera's PROP began last month with a roof control seminar at the National Mine Health and Safety Academy near Beckley, W.Va.