Every surface mine has them. They’re the lifeline of the production system, just as important as trucks and shovels, and they can be a mining operation’s greatest asset or its greatest liability. What are they? Haul roads—and mine haul road design and maintenance has a direct effect on productivity and profitability.
Haul road conditions dictate speed, fuel burn, tire life, safety and annual tonnage moved. Clean, smooth surfaces extend tire life for mine haul trucks and reduce the chance of machine damage or accidents due to road hazards. Smooth, constant grades minimize transmission shifts, enable drivers to maintain higher average speeds, allow more constant braking effort on returns, and reduce spillage and fuel consumption.
On the other hand, poorly designed or maintained mining haul roads can lead to dramatically increased costs caused by lost production time, shortened tire life, greater fuel usage, excessive component wear, major equipment repair and replacement, and safety issues. Even exceptionally designed haul roads require time and effort to keep in top shape. Regular maintenance helps eliminate the small decreases in speed—and increases in cycle times—that negatively affect hourly and annual production.
Fortunately, several new tools and technologies are available to help mine operation managers enhance haul road construction and maintenance practices, with the ultimate goal of increasing tire and mining truck life, improving fuel economy and reducing cost per ton.
Onboard machine systems, for example, can assess road conditions and quantify the severity of the haul, with sensors measuring factors such as component loading, impact shock, strut pressure data, transmission shift frequency, gear on grade, brake/retarder use and more. Many of these systems can then transmit real-time data to operators and maintenance personnel about problem areas to avoid and correct.
In addition, software packages can simulate mining truck productivity and estimate cost per ton on various haul road profiles. Mines can use these tools to determine if mining trucks are achieving predicted speed on grades, as well as cycling and waiting at the loader in predicted time ranges. With this data, operation managers can investigate possible causes behind delays—Are rough or slippery roads or tight corners forcing operators to slow down? Is rolling resistance higher than planned? Is visibility poor due to dust or obscured views?—and make the necessary adjustments.
The tracking capabilities now built into many mining machines also can assist with haul road maintenance for mines. These systems generate reports showing where health and operational alerts occur, which can help drivers and operation managers spot site problems—including suboptimal haul road conditions—that affect mining equipment availability, health and asset life.
Good haul road construction and maintenance practices are key to operating a cost-efficient fleet of trucks and a profitable mine. Are your haul roads built to handle the loads today’s trucks can carry? What is your mine doing to keep haul roads in top shape? Share your experiences with us on Facebook or Twitter.