Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/233439
OPERATIONSExperience ILLUSTRATED Voices of Cynthia Kirby "D t ump point safety is an important concern because haul truck dumping is performed frequently, and the potential for an undesired outcome, such as mobile equipment upset, could result in injury," says Cynthia Kirby, corporate director safety and health, Vulcan Materials Co. "When the task is being performed, personal hazard awareness and proper controls should be understood and followed." Hazard awareness skills include thorough workplace shift inspections, looking for changes from the previous shift or day, sloughed material, sufficient lighting, and adequate berms that serve as an indicator of the edge. A berm should be made of substantial material with a wide base, and it must be mid-axle height of the largest piece of mobile equipment that travels in the area. "Mobile equipment operators, supervisors, and all personnel should keep a safe distance from the edge of any dump point, stockpile, or high wall," Kirby adds. "They should be alert to recent freeze-thaw conditions, look for cracks (a warning sign of an unstable slope) or erosion, and observe and evaluate that the face is not under-cut and no equipment/trucks are being loaded directly below. Any of these factors could negatively affect ground stability and increase the likelihood of potential mobile equipment upset." According to Kirby, Vulcan Materials employs a 'dump and push' practice at stockpiles, spoils piles, and high-wall areas. Material is dumped short of the edge. Then, mobile equipment such as dozers, loaders, or excavators are used to push the material forward, always maintaining a mound of material between the edge and where the next load of material will be dumped. A spotter can be used to evaluate ground conditions and to communicate the condition of the dumping location to the driver. Training is important. "Training is done initially and repeatedly," Kirby says. "Employees and plant managers are trained on safe work practices and how to avoid potential accidents." Truck drivers are taught, among other things, not to rely on a berm for stopping a truck, but that they should back slowly and come to a gradual stop before reaching the berm. They are also taught to back perpendicular to the edge at the dump point and to avoid dumping below energized and overhead power distribution lines. Communication is considered to be a key element in dump point safety as well. All employees are encouraged to speak up. "When operators, spotters, or foremen believe there is an unstable, unsafe condition, they should communicate that to their supervisor or plant manager," Kirby says. "If the condition needs to be corrected, a work-plan for correcting the unsafe condition should be devised and performed." Ahmed Hamadi L t afarge considers tip-over accidents to be of the greatest concern, says Ahmed Hamadi, operations manager for Lafarge's Midwest Aggregates. These accidents often result in fatal injuries, especially when dumping from a high bench or the top of a stockpile or spoils pile. Lafarge doesn't commonly dump from a stockpile or over a berm on a high wall or bench, according to Hamadi. "Lafarge policy has always been to avoid the practice all together," he says, "and we have come up with alternative solutions. But in the rare case where we have to dump over a mining bench, we take extra precautions. Our preferred method is to dump loads a safe distance from the crest or bench and push it over the edge with a dozer or loader using a bumper of material between the machine and the face of the bench to create a safe zone and minimize the risk. Inspection of the area is important, as well, so a spotter is sometimes needed, depending on the situation." The company believes it is important to train equipment operators to recognize stockpile and dump point hazards. Lafarge's Stockpile and Surge Pile Advisory is used to train company truck drivers and loader operators typically involved in stockpiling. "The advisory goes a bit beyond what MSHA requires to manage and prevent tip overs when stockpiling or dumping over the edge of a mining bench," Hamadi says. Some of the tips found in the advisory include: • To prevent tipping, drivers should back up perpendicular to the dumping berm, shift the truck to neutral, and set brakes. • The driver should not attempt to dump the material if it sticks in the bed, especially if the material continues to stick after the bed has been raised two-thirds of the way. • Lastly, lower the truck bed before driving away from the dump point. Lafarge conducts annual refresher training for seasoned employees and new training over all company standards and advisories for all its new hires. "This is coupled with refreshers throughout the year during weekly and monthly safety conversations," Hamadi adds. "Furthermore, all tip-over incidents in the industry are shared immediately and used as a training opportunity." The majority of the incidents Lafarge has encountered have been behavior driven, so the company tries to enforce positive employee behavior. Employees are encouraged to look out for each other. "We usually have multiple truck drivers working at the same time, so they look out for one another on the approach," Hamadi says. "If they see anything out of the ordinary, they are empowered to speak up. That's something we emphasize." Aggregates Manager OperationsIllustrated_AGRM0114.indd 20 12/13/13 9:08 AM