The Influence of Seam Height on Lost-Time Injury and Fatality Rates at Small Underground Bituminous Coal Mines

Abstract

Due to variations in the thickness of U.S. coal seams, there is great variability in the height of the roof where underground miners work. Restrictions imposed by low seam heights have important safety consequences. As the height of their workplace decreases, miners must stoop, duck walk, or crawl, and their vision, posture, and mobility become increasingly restricted. Low seam height also places important restrictions on the design of mobile equipment and other mining machinery. Using the employment and injury data reported to the Mine Safety and Health Administration (MSHA) from 1990 to 1996, small underground bituminous coal mines with less than 50 employees were stratified by average coal seam height according to the following categories: low (< or =42"), medium (43"-60"), and high (> or =61"). Injury rates for both nonfatal days lost and fatality cases were examined by seam height and leading type of injury incidents. The leading types of incidents associated with fatalities were roof falls and powered haulage equipment. In comparison to high-seam mines, miners working in low or medium seams are at higher risk of being killed by powered haulage equipment, roof bolting machines, and falls of unsupported roof. The leading types of incidents associated with nonfatal injuries were handling materials and powered haulage. As mining height decreases, miners are at increasingly higher risk of having a nonfatal injury from incidents involving roof bolting machines, load-haul-dump equipment, personnel carriers, and powered haulage conveyors. As mining height increases, miners are at increasingly higher risk of having a nonfatal injury from slips and falls and incidents involving shuttle cars and roof and rib falls. Knee injuries are a particularly severe problem in low-seam mines. The rate of injuries to miners while crawling or kneeling is 10 times higher in low seams than in high seams.

Forces and Moments on the Knee During Kneeling and Squatting

“…Low-seam coal miners are required to work in low seam heights (1.1 m [42 inches] or less), which restrict their postures, forcing them to kneel, crawl, and squat to perform work. Low-seam coalmines report 10 times as many lost-time injuries related to these postures as high-seam mines, with 75% of these injuries being to the knee (Peters et al, 2001). Knee injuries are also the most prevalent, accounting for 17% of total injury costs to mining companies-more than any other body part, including the lower back (Gallagher et al, 2009).…”

Citation-related reliability analysis for a pilot sample of underground coal mines

“…Mine size is highly correlated with the seam height and smaller mines tend to operate in significantly thinner coal seams than large mines. Miners are at higher risk of having a nonfatal injury as mining height decreases (Peters et al, 2001).…”

Uticaj profesionalnih štetnosti na traumatizam radnika „Rudnika i termoelektrane Ugljevik”

“…Naši rezultati su u saglasnosti sa rezultatima koje navode i drugi autori u svojim istraživanjima [3,10,11,19,20].…”