Operations Illustrated: Benchmark Your Load-Haul Operations
Gather Operational Intelligence
It’s no secret that operating costs are largely comprised of equipment, personnel, and fuel. Therefore, being able to improve performance in each of these categories is essential to efficient operations and lowest cost per ton.
By collecting appropriate data and establishing meaningful benchmarks in each category, operators are able to better understand what constitutes desired performance, identify the equipment and people who produce the best results, and develop best practices that can be used across the operation or the company.
In many operations, telematics provide this data, particularly with load-haul equipment. “One of the things that the equipment manager is tracking is utilization of the machine: how many hours it is working, idling, and traveling,” says Doug Phillips, product manager for Volvo Construction Products, based in Shippensburg, Pa.
Fuel usage also is tracked through telematics. “If an equipment manager has three loaders and sees that one is burning 5 gallons per hour, while another is burning 5.3, and a third is burning 7, he knows someone needs operator training to bring that back in line,” he says. As fuel consumption is tracked, use of automatic engine shutdown devices, which turn the engine off after it idles for a set time period — typically about 5 minutes, is increasingly common and helps to lower load-haul costs.
Telematics can also issue equipment warnings, such as if the transmission is being misused or abused. “On trucks, it shows if engines are being oversped, and if they are using retarders to slow down the trucks or burning off extension brake pads,” Phillips says. “I tell operators that it costs you nothing to press that retarder pad, but every time you press the brake pedal, it costs you money.”
Radnor, Pa.-based Preferred Sands does not use telematics. Rather, it focuses on activity-based costs to determine the most bang for its buck. According to Bob Carter, senior vice president of operations, the company’s strategy is to collect data on the assortment of equipment at the sites it has acquired, then set standards on equipment types throughout the company.
“We have five active plants, so we have the ability not only to compare our mining costs against the different plants, but to be able to break that down into asset focus,” Carter says.
As cost comparisons are analyzed, factors such as geologic differences are taken into account, and economic analysis is used to drive equipment standardization as much as feasible throughout the company. “A lot of my initial focus was in creating a reliable, repeatable, and process-driven model within my plant operations,” Carter explains. “That, ultimately, drives the utilization and the uptime of your plants.”
Keep haul road grades under 9 percent and maintain clean pathways to allow trucks to travel quickly. The hydraulic suspension system in some newer haul trucks provides greater cushioning of impact to improve operator comfort, allowing haul truck operators to travel at higher speeds. It is important to keep in mind, however, that the truck patterns will be dictated by the slowest moving truck at the site.
Loaders are being built stronger than ever with bucket designs that provide greater retention of material. This allows for greater bucket capacity and quicker loading. At the same time, automatic braking features allow the loader operator to go into the pile, back up, and pull toward the truck without ever touching the brakes.
Consider all options when making load-haul decisions. After comparing the cost of conveyors and power versus trucks and fuel — and taking into account conveyor movements as the face location changes — Preferred Sands installed transport conveyors in most of its operations to reduce haul truck usage.
The loader operator should take the lead on establishing customer traffic patterns. Ideally, the bucket should be full and raised in the air when the truck pulls up to be loaded. One way to communicate the correct stopping point is for the loader operator to beep his horn to let the truck driver know he’s in the right position.
Bucket scales are commonly used on topside loaders to ensure safe and accurate loads before trucks leave the site. Many loader operators communicate via CB with the scale house to check that the scale house’s actual weight matches that of the loader scale measurement. Cross checking lets the loader operator know if his scales need to be calibrated.
Equipment manufacturers are incorporating safety concerns into their new equipment design. Late model equipment features much more glass in the cab and often takes great care to minimize blind spots. For example, newer trucks often sport sloped hoods to improve visibility in front of the unit. Rear back-up cameras are also standard equipment on many models.
Bob Carter is the senior vice president of operations for Preferred Sands of Radnor, Pa. Carter has a bachelor’s degree in chemical engineering and a master’s in business administration — both from the University of Utah at Salt Lake City. He has more than 20 years of experience in managing minerals companies, as well as software and engineering businesses.
Doug Phillips is the product manager for Shippensburg, Pa.-based Volvo Construction Products. He has been with the company for 20 years, beginning by building wheel loaders and leading the quality team. For the last six years, he has served as product manager for wheel loaders and has specialized in the aggregate industry.
VOICES OF EXPERIENCE
Knowledge is power, particularly when it comes to making equipment-related decisions, says Bob Carter, senior vice president of operations for Radnor, Pa.-based Preferred Sands. Recently, the company collected data in a new computerized maintenance system so it can compare performance from plant to plant.
“In order to drive asset utilization, you’ve got to be able to track the frequency of failures,” Carter says. “The cost of those failures drives a lot of your key performance indicators.”
Once the relevant data was gathered, Carter said he looked at it from an activity-based perspective. This entailed reviewing work orders against assets, as well as categories of assets and plants, so he could mine the data for a series of “top 10” reports that allowed him to establish benchmarks for the various activities, such as loading and hauling.
The company then began to make decisions on equipment standardization, which was important because it grew through acquisition and had equipment from up to half a dozen manufacturers within one type of equipment. “When you look at standardizing your equipment, there are two things that drive the decision,” Carter says, “the knowledge of the equipment — being able to compare its failure points and its performance — and your spare parts costs.”
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.
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