Operations Illustrated: Benchmark Your Load-Haul Operations
As it developed standard assets, the company centralized purchasing. “It really is a cost decision,” Carter says. “It’s the cost of initial purchase, cost of maintenance, and cost of inventory.”
He elaborates that the benefits of streamlining equipment vendors are two-fold. First, it relies on best-in-class equipment. Standardization allowed the company to lower its fleet costs by approximately $1 million per site because it no longer needed to maintain excess inventory to offset the impact of equipment failures. Next, parts inventory is much more efficient. “If a vendor doesn’t have a part, we’re able to share our inventory across our plants during critical times to get a plant back up,” he explains.
The data-driven process yielded dramatic results when it comes to loading and hauling at Preferred Sands sites. With the exception of one site, all of the mines added transport conveyors to reduce the use of haul trucks. “The cost of fuel went up so high that the cost to operate became pretty extreme, so we started using a lot of jump conveyors that we could move in mining operations in order to get closer to the walls,” Carter says. “We were able to reduce our costs by about 20 percent by putting in the conveyors.”
In most cases, bigger is better for today’s operators, says Doug Phillips, product manager for Shippensburg, Pa.-based Volvo Construction Products. “During the economic crash, there were a lot of quarries that went away,” he explains. “A lot of the guys who survived are utilizing larger equipment.”
To improve the efficiency of load-haul operations, various design changes are being implemented. “We’re designing more efficient buckets and loaders that are stronger than they’ve ever been before,” Phillips says. Through minor modifications, loader capacity has grown from 7 yards to more than 8 yards, depending on material density.
A significant improvement, Phillips says, is the introduction of even larger wheel loaders. For example, with its 9-cubic-yard bucket, the Volvo L250 loader allows on-highway trucks to be filled in two passes rather than the normal three pulls of material. “We’ve cut cycle times by a third for those guys who are loading on-highway trucks,” Phillips explains. “Most things save pennies per ton. This is huge.”
While the machines have grown, they have also been tweaked to become more fuel efficient. Volvo’s new OptiShift transmission automatically applies the brake when shifting between forward and reverse, allowing the operator to focus on loading. “When the computer sees these shifts being made, it applies the brakes,” Phillips says. “It does what the operator used to do, but faster and more efficiently.”
Operators are also learning how to leverage engines that achieve high torque at a low rpm to improve fuel efficiency. “We’re giving the operator more power at the mid-range,” Phillips explains. Traditionally, operators hold the pedal to the floor for more power, so a pedal hesitates at optimal torque to let the operator know he is at the proper rpm. “During other operations, he can go past that step and back to full throttle,” he says.
While new technology offers benefits, it’s important to train operators. Fear is not uncommon among who are comfortable with familiar equipment. “As with anything, a lot of people resist change,” Phillips says. “I talk to these guys about going to the car lot with my dad when I was younger and hearing him tell the salesman that he wanted a truck with manual, roll up windows.” Concerns about new technology failure are as prevalent now as they were then, he notes. But with proper training, new features — from automatic windows to automatic braking — are likely to win the operator over.