Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/387031
TIONS ILLUSTRATED OUR EXPERTS Haul Road Construction and Maintenance OCTOBER 2014 Kent Clifton is senior market professional – Mining Equip- ment Application at Caterpil- lar, Inc. He joined Caterpillar in 1991 after 12 years working with Cat Dealers and as a contractor in the quarry industry. He worked as prod- uct operator/demonstrator at the Tinaja Hills Demonstration & Learning Center, then as product operator/specialist for large mining products. He worked two years as ap- plication/marketing specialist in the Asia Pacifi c Division before taking his current position as a mining machine application specialist focusing on helping mines reduce their cost per ton and increase production. Bryan Smith is mine develop- ment and blasting manager at Luck Stone. He graduated from Virginia Tech with a mining engineering degree, and has been involved in the aggregates industry for 34 years, in both operations and engineering positions. Roles have included foreman, plant manager, area manager, mining engineering manager, and director of engineering. He has routinely dealt with everything associated with operations, including haul roads. A well-designed haul road should maintain a smooth, constant grade of no more than 12 percent. This will minimize the number of transmission shifts necessary for a haul truck to travel the road and will enable it to maintain a good speed. In switchback areas, a good super-elevated curve will allow a truck to maintain its downhill speed through the curve without having to apply the brakes. Keep the edges of haul roads clear of any vegetation or other obstructions that might block the vision of haul truck drivers or equipment operators. Corners and crests in the road should be designed so that operators have good visibility in order to avoid hazards, such as on-coming traffi c or material spillage, without having to slow down. Slowing down means less production. Motor graders are considered the best tool for maintaining haul roads, but they aren't the only viable tool. Wheel loaders can handle repairs and patches quickly and easily. Loaders are almost constantly traveling in the pit and loadout areas, so it's easy for them to pick up a load of material, drop it into a pothole or a washout after a rainstorm, and drag the bucket across the material to press it into the damaged area and smooth out the road. Water trucks can help with haul road maintenance by reduc- ing the air-borne dust level. Be sure to use a pumped spray to spread the water out evenly across the haul road to help prevent the water from pooling in one area. Pooling water can cause rutting and potholes, which can cause haul trucks to travel at a slower speed. Design roads with a constant grade 2 3 Curves should allow clear line of sight 5 Maintenance, maintenance, and more maintenance 6 Control dust with water trucks