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Mine Safety and Health Administration MSHA's Accident Prevention Program
Miner's Tip

Working in Low Coal

Safety Something YOU can live with!
Mine Type: Underground Coal
Category: General Safety

Extra care must be taken when working in low mined heights to overcome the greater hazards that arise from reduced visibility.

Drawing depicting miner crawling Working in low coal isn't just hard on your back and knees. The reduced visibility from "duck walking" or crawling in low mining heights brings a new set of problems. When it comes to seeing --- or not seeing the mine roof, poor visibility can be deadly. A NIOSH study analyzing roof falls in small mines for the time period 1990-1996 revealed that "in comparison to seams above 60 inches, the rate of fatalities caused by falls of UNSUPPORTED roof in lower seams is twice as high". (Results of this study were published in the Holmes Safety Association Bulletin, July/August, 1999 edition.)

Everybody remembers the safety slogan "Inby is Out", but when working in low coal you have to work harder at knowing where unsupported roof is. Take a good look at the required warning device marking the last row of permanent roof supports. Is it enough to catch one's eye when stooped over or crawling? If not, maybe it needs to be made longer -- or maybe multiple streamers need to be hung to assure this device really gets a person's attention. In addition, it is a good idea to hang streamers marking the last row of bolts on either side of a line curtain. This is helpful for someone traveling up the return entry who may not see the warning device if it is only placed on the intake side.

Also, you should be especially alert for the last row of bolts when you are operating equipment in low coal. Remember, the size of the vision "window" over top, or along the side of the machinery, is reduced in low coal, often making it very difficult to see the roof bolts or the marker device.
Reissued: 04/30/2002
Tag # AP2002-M009

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