Knife River Corp., based in Bismarck, N.D., has several operations in the northern United States, where daylight hours can be short, especially during the winter months. “In the north, we work quite a bit in the dark, and the mechanics are always out there after hours,” Hayden says. “You always need to know where you are.” Always know your hazards. Discuss the hazards and how they can lead to an accident. Have there been past slips or trips near the highwall?
Even with lights on a crusher and a loader, “You really need to keep your bearings,” Hayden warns, adding that people not working on the equipment need to stay away from it. He suggests talking to someone on a radio instead of being out in the pit. “If you absolutely have to go down there, get visual contact, turn on your beacon, or flash your lights,” Hayden advises. And though it may seem obvious, Hayden reminds workers that they need to wear reflective clothing and hard hats. And if a person cannot accomplish a task by radio and absolutely must go out in the pit near the highwall or stockpile, “Do not go near the operator until he or she stops,” Hayden cautions.
When stockpiling with a loader, there needs to be good berms on either side of the roadway. “A good berm is mid-axle height of the largest piece of equipment traveling the roadway, according to MSHA law,” says Hayden. “This is the berm standard. All of the berms need to be mid-axle height of the largest piece of mobile equipment that usually travels the roadway.”
With the stockpiles themselves, the equipment operators need to ensure there is no slabbing. For example, if crushing is done in one place and then material is taken to another place, the stockpile will be long and thin with berms on both sides if a belly dump and blade are used. With all the trucks then driving over the top of the stockpile, the weight compacts it. “In these kinds of stockpiles, you can have slabbing,” Hayden says. “If large chunks of material collapse onto the loader bucket, it can raise the back of the loader or can pick you up if a loader of insufficient size is used. If you’re in the pit, it can fall down.” Hayden says a good rule to follow is, “If in doubt, push it down.”
Top tips for highwall and berm safety
Inspect, inspect, inspect. Build good berms, inspect them, and maintain them.
Control access to highwalls and stockpiles.
Be aware of your surroundings and control your hazards. Conduct examinations of the highwall before, during, and after every rain, freeze, or thaw.
Inspect your stockpile and berms. Inspect and evaluate them, and eliminate or control any hazards. Scale down loose, hazardous material, and do not work under loose material for any reason.
If it’s a new pit, call for your locates and know what’s in the ground. You don’t want to hit a major gas line or pipe line.
Pay special attention when working in the corners of box cuts.
Increase the number of benches at each highwall to catch falling material.
The Small Mine Office developed a series of weekly ToolBox talks that can be used by small mine operators and others to hold safety and health discussions for employees at their mining operations. These ToolBox talks were developed in consultation with members of the mining community. To get the free app, enter http://www.gettag.mobi into your browser.