 A lot has been done over the past 30 years to improve roof and rib control technology. And there's been a reduction in roof and rib fatalities. Even so, we need always to pay attention to roof and rib control. For as long as coal has been mined underground, roof and rib falls have accounted for more fatalities than any other source. Here's why. Coal comes from plant matter covered by layers of sediment. Over millions of years, the sediment turned to rock, compressed the plant matter and transformed it into coal. The composition of the sedimentary rock that covers the coal determines the strength of the roof at your mine. This is why roof and rib conditions vary from mine to mine and sometimes from section to section within a mine. Combine this with other geologic occurrences like faults, slips, joints, cattle bottoms, thinly laminated rock, and weak or brittle rock. Humidity also plays a role in further deteriorating the immediate roof. Now what does this mean to you? Well, every day you have to deal with changing geological conditions. Every cut of coal opens up unknown territory and reveals new potential hazards. Many mines are in coal reserves that in the past were avoided because of poor roof conditions. Mines are often deeper than they used to be and they may have old works over or under them which can place additional stress on the roof and ribs. Miners often move from mine to mine. Every time they do, even if they are experienced, they have to learn about the conditions, work practices, and other hazards at their new mine. It's even more dangerous for inexperienced miners. Studies tell us that many fatalities involve minors who are new to an operation or who have little mining experience. By recognizing and understanding what makes roof and rib hazards so dangerous, we can work together to prevent injuries due to roof falls and rib rolls. Although the mine operator is responsible for providing you with the tools and training to do your job, it's your responsibility to use these resources to make conditions safe for you and your fellow miners. Your first line of defense is to pay attention to changing roof and rib conditions and to make frequent and thorough roof and rib evaluations. Conditions change constantly and your supervisor may not be aware of a change, so don't take it for granted that they know. Discuss any roof control concerns you have with your supervisor. You can do a lot to protect yourself. You have heard over and over that you need to know your mine's roof control plan Do you? Why is knowledge of the plan important to you? Let's find out. A roof control plan is not merely the brand or type of bolts that you put in a roof. To design a good roof control plan you have to get involved early on and consider the coal bed that you'll be mining. You have to consider the depth of the coal bed into the ground. You have to, through core drilling, you have to analyze the strata that lies above the coal bed and the surface. And all this figures into designing your roof control plan. Your mine's roof control plan tells the minimum that has to be done under normal conditions to support the roof. You've got to know and follow your plan's requirements. If you fail to install the proper supports required by your plan, then the roof is inadequately supported and you have jeopardized the safety of yourself and your fellow miners. The torque range is 175. A study of fatal roof fall accidents found that almost one-third of the victims were in by roof support when they were killed. Why did these miners go in by? Sometimes it's a worker that's wanting to do good and wants to hurry and hustle because a lot of times people are pressed and pushed to do a good job to maintain a job. But ultimately I think it's just a it's just a pause in a person's mind that they don't think of the ramifications that are involved when they go out beyond roof support. I don't think they've been taught or showed or trained to the extent that they need that they understand all the things that are involved and that they are actually taking their life in their own hands. And not only their life but they're endangering the livelihood of their entire crew. It is extremely important to mark the last row of bolts with highly visible markers to prevent accidental travel in by roof support. And remember, when working in low coal it may be difficult to look at the roof all the time. You're on the front line of danger if you are a continuous miner operator or helper since you're generally the miner who works closest to the pillar line in an area that's most susceptible to roof rib falls. If you're a miner operator you must make sure that you are positioned under safe roof and ribs before mining coal. Other miners and supervisors who work on retreat sections are not exempt from the hazards of roof and rib falls. The use of mobile roof support units in pillaring operations has increased over the past 10 years. An MRS unit helps to limit your exposure on the pillar line by reducing or eliminating the need for roadway timbers and radius turn posts. Don't, however, develop an attitude of complacency or a false sense of security. To realize the safety advantages afforded by MRS units you must follow proper operating procedures and safety precautions. The maximum entry and cross-cut widths specified in your roof control plan are based on the conditions at your mine. It is vital for continuous miner operators to stay within these maximum widths. And supplemental support must be installed if these maximum widths are exceeded. There are many programs available that can be used to design properly sized pillars. The software accounts for factors such as entry and cross-cut width and height, overburden, coal strength, cross-cut angles and pillar dimensions. Follow the roof-rib control plan at all times. Pay attention to the safety provisions in the plan that cover breaker and radius turn post locations, mining sequences, depth of cut, and operator location. It's especially important to do so when mining the last lift or final push. Intersections are dangerous. Although intersections account for only 10 to 20% of the developed area in a coal mine, 50% of the roof fall fatalities reviewed in recent years occurred at intersections. Some mines see much poorer roof-rib conditions in four-way intersections than in three-way intersections. Many cause four-way intersections create larger roof spans. Staggering cross-cuts to eliminate four-way intersections can help reduce the potential for a roof fall. Mines with abnormal roof and rib conditions in intersections need additional roof support in these areas. This supplemental support at intersections should be incorporated into the roof control plan. Longwall mining generally appears to be the safest underground mining method because of the protection from roof falls provided by longwall shield canopies during normal mining operations. Even so, there are times when miners have to work near the shield canopy tips or between the tips and the longwall face. This generally occurs when miners perform maintenance on the shearer or face conveyor and during longwall recovery operations. Five accidents testified to the potential roof and rib hazards on a longwall section. Three fatalities occurred during maintenance and recovery operations. A fourth happened because of a rib roll near the stage loader, and a fifth miner died from a coal outburst on the face. Roof bolter operators today often install many kinds of high-quality roof support systems. The bolts we have here are some of the supplemental roof supports we use. This is a 7-foot cable truss. They're installed on a 45-degree angle to divert the weight of an entry back over the pillars. This is an 8-foot combination bolt. We use those in our intersections in a star pattern for added support on advancement, but it really helps out when we're building. These are the 14-foot cable bolt that we use. They help when the different stratas of rock separate above the 8-footers, and this is our 4-foot conventional bolts. We use those for a rib bolting. The obvious advantage of this variety is that a mine can customize its roof support system to specific roof conditions. Follow the manufacturer's recommendations as proper installation procedure is essential to good roof bolt performance. Immediately contact your supervisor if you have any questions or concerns regarding the roof bolts that you are installing. ATRS is a great help. Do you know how to maximize the protection that an ATRS system can provide? Here's what you can do if you are a roof bolter. Report all mechanical or hydraulic problems with the ATRS system to your supervisor. Always make a thorough examination of roof and ribs before doing any work. Perform sound and vibration checks. Follow the bolt installation sequence in your mine's roof control plan. Following the approved bolting sequence is extremely critical when operating a single-boom roof bolting machine. Observe the maximum distance that an ATRS system can be set beyond the last row of bolts as listed in the roof control plan. MSHA provides technical assistance to the mining industry on roof control issues including specialized laboratory and field services. Geologists perform remote sensing linear analysis to help mine operators identify areas of potentially poor roof conditions. Technical support engineers evaluate roof support systems by conducting both laboratory and in-mine testing. They also conduct in-mine evaluations of ATRS systems and canopies on mining equipment. If you're an operator, you must provide a safe workplace by supporting or controlling the roof, face and ribs in areas where persons work or travel. Develop and follow an MSHA-approved roof control plan for your mind. Propose revisions to the roof control plan when prevailing conditions indicate that the current plan is not suitable or when accidents or injuries experienced at the mine indicate the plan is not adequate. Provide adequate training to miners about your mind's roof control plan and make sure any changes made in the plan are fully discussed and thoroughly understood before they are implemented. Provide miners with adequate machines, tools and materials to safely install roof support. Report to MSHA, unplanned roof falls, at or above the anchorage zone in active workings where roof bolts are in use. A roof and rib fall on active workings that impairs ventilation or impedes passage. A coal outburst that causes withdrawal of miners or which disrupts regular mining activities for more than one hour. And to conduct frequent and thorough examinations of roof, face and ribs. The losses that you have the right to tell MSHA at any time about a violation of the act, a violation of health and safety standards or the existence of an imminent danger. Expect that all necessary roof control related equipment are in place, used and properly maintained to inspect a copy of the approved roof control plan of the underground coal mine where you work. Receive training on roof and ground control and ventilation plans in effect at your mine. To be instructed in approved revisions to your mine's roof control plan before the approved revision is implemented. Remember, take five and stay alive. Know and follow your mine's roof control plan. Check the roof and ribs often. Be aware of your surroundings. Watch for changing conditions. Discuss all roof control concerns with your supervisor and never go under unsupported roof. For additional information, visit our website at www.mshg.gov.