Results from recent on-site studies show that managing mine fleet assets even slightly more effectively can often have a startlingly positive effect on overall costs Results from recent on-site studies show that managing mine fleet assets even slightly more effectively can often have a startlingly positive effect on overall costs

Using fleet management software solutions to identify, analyze and eliminate problem areas that often result in higher-than-necessary operating costs

By Russell A. Carter, Managing Editor

Controlling costs is the mining industry’s main mantra in today’s economic environment, and the capabilities of modern fleet management suites from Caterpillar, Modular Mining Systems, Wenco, Carlson Software, and others provide a vast array of tools for mine operators to identify and analyze areas in which rising costs are a concern. However, the sheer number of available features in these suites may prove to be overwhelming for busy, distracted mine managers and supervisors, thus diminishing their overall usefulness. Consequently, several of the major fleet management solutions providers have recently issued helpful, “look at this” tips, guidelines, updates and presentations focused on features that can specifically address common fleet management issues that relate to cost containment and reduction.

Mining is an expensive business. It’s unlikely that anyone involved in the industry needs to be reminded of the costs associated with equipment, payroll and consumables when it comes to fleet operations. However, managing fleet assets even slightly more effectively often can have a startlingly positive effect on overall costs, according to a recent Cat webinar and associated white paper that looked at five specific areas identified by its customers as primary generators of higher costs: process variability, unscheduled repairs, fuel costs, shift changes and collisions.*

The white paper offers specific examples describing the nature, effect and recommended solution proposed by Cat’s experts for controlling or reducing the economic impact of these problem areas, and for achieving the lowest possible cost per ton overall. Here are a few of those examples.

Problem: Leveling out process variability. This is a hard topic to quantify, Cat warns, because variability can be present in almost any aspect of fleet operations. However, a close look at each major phase of the mining sequence can reveal areas in which unpredictability can cause cost issues.

  • Operator Performance—This is one of the most common examples of process variability. Obviously, not all operators are equal in every way. There will always be operators who are tired from a restless night or distracted by other matters during their shifts, as well as some who consistently outperform their peers.
  • Inconsistent Cycle Times—Cycle times are affected by the performance of both loaders and trucks. Loading tool cycle times may be inconsistent, resulting in inefficient loading that negatively impacts the entire fleet. Trucks may be traveling at suboptimal speeds or taking longer routes than necessary, which also increases cycle times— thereby increasing fuel costs, wear and tear, and overall cost per ton.
  • Drilling Variability—One of the easiest places to measure the impact of process variability is in drilling. Incorrect hole placement and depth can have a negative impact on costs through out the entire value chain. Improper pattern spacing creates significant waste of both drill consumables and explosives, and can even create a need to re-drill holes entirely. Poorly blasted material is difficult to load and haul efficiently, increasing costs in this phase of the operation, and it can also reduce the mine’s total throughput if rock must be broken up before it can be placed in the crusher.
  • Overdrilling and Underdrilling—Drilling holes to an improper depth can also contribute to high costs. If holes are too shallow, blasting may leave behind unexploded rock, which can create challenging digging conditions, cause damage to loading tools, and increase truck loading time. Uneven floor conditions can cause pitching, racking and rolling that damages the truck’s frame and tires. Even auxiliary equipment experiences increased wear, because it is much more difficult to maintain grade on an improperly blasted bench.

Overdrilled holes can add costs to drill consumables and maintenance, as well as contribute to lost productivity. They can also lead to overuse of explosives, which further increases costs. And just like an underdrilled hole, an overdrilled hole makes for more work when it comes to maintaining grade on the bench.

Solution: Reducing costs by improving drill accuracy. At a gold mine in Brazil, a Caterpillar customer decided to use Cat MineStar Terrain for drilling to reduce process variability in its drilling operations. The result was a dramatic reduction in costs—not just in drilling, but throughout the operation.

After using Terrain for drilling for one complete drill and blast operation, the mine found that it had been overdrilling holes by an average of 1 m (3.2 ft). With Terrain for drilling, the margin of error dropped to under 10 cm (4 in.), reducing total drilling time by 6% over the course of a year—a savings of more than 1,200 hours. This also resulted in more efficient use of drill consumables and explosives for a cost reduction of $200,000.

The mine also improved its pattern spacing, increasing the accuracy of hole spacing and placement and resulting in more homogeneous blasted material. This translated into a 5% increase in rope shovel productivity, as well as reduced maintenance time and a 450-hour reduction in total excavation time. All this combined to save the customer an additional $250,000.

Problem: Coping with unscheduled repairs. Cat noted that there are a multitude of causes for unscheduled repairs, including:

  • Failure to execute a planned maintenance strategy. Even the best of plans will fail if it is not consistently executed.
  • Poor maintenance practices, including failure to monitor the condition of components, which can allow minor problems to escalate into major ones.
  • Poor haul road or dump area conditions, which can cause damage not only to tires but to machines as well.
  • Operator abuse.

Solution: Reduce costs by preventing failures. To illustrate how significant the difference between planned and unplanned repairs can be, Cat cited a customer mine in Chile. Using Cat Equipment Care Advisor (Cat ECA), a tool in the MineStar Health program, Cat dealer Condition Monitoring personnel detected a potential high-pressure pump issue in a 795F mining truck. The team alerted the on-site dealer maintenance crew, which addressed the potential issue before a failure occurred—all within a single shift.

Even though the machine was down for only 12 hours, the issue amounted to $60,000 in lost productivity. The part itself cost less than $10,000, and the labor to make the repair cost less than $5,000. All told, this one issue cost the mine about $75,000.

However, the customer reported that early detection of the issue saved them nearly $1 million by preventing the part failure. If the part had failed during production, the impact would have been felt in a number of ways. Fuel would have become contaminated, and over time, the broken pieces of the pump would have shattered and affected other systems, resulting in a total engine failure. The dealer calculated 110 hours of downtime would have been necessary to make that repair, with around $550,000 in lost productivity. Add that to $375,000 for parts and more than $65,000 in labor, and the mine would’ve lost $990,000.

Problem: Squeezing more tons per mile from fuel consumption. Costs that can be tied to fuel go beyond its actual purchase. For example, rehandling material unnecessarily burns fuel without contributing to overall production. Fueling equipment too often results in excess downtime. Even the design of the mine itself can contribute: If trucks are taking a longer route than necessary, every cycle is burning that much extra fuel. The ultimate goal of every mine should be to move as many tons as possible with every liter of fuel burned.

Solution: Focus on fuel management. An iron ore mine in Australia collaborated with a Cat dealer to find a way to decrease mean time between fueling. Initially, the mine’s trucks averaged a little more than 13 hours between fuelings, which meant the trucks were fueled at the beginning of or during every single shift. The dealer provided the change management and training necessary to implement the fueling module within Fleet, which helped the mine optimize equipment utilization and increase mean time between fueling. By the end of the implementation, the mine’s average time between fueling was almost 22 hours—a number that has continued to increase. All told, Fleet helped the mine produce more than 1 million more tons per year using the same number of trucks.

At another iron ore mine in South Africa, Cat helped a customer address concerns about fuel costs and a need to bring the mine in line with strict emissions standards.

Since the pit is relatively shallow and the mine’s 795F AC trucks travel well below their maximum speed, they were not making efficient use of their engines’ horsepower. With this in mind, Caterpillar dealer Barloworld installed software that decreased the engine’s horsepower, reducing fuel usage and emissions accordingly.

This small change improved the mine’s liters per ton ratio by almost 9%. The liters used per hour by each truck were reduced by 18.9 liters (5 gallons), saving the mine 2.35 million liters (621,000 gallons) over 36 months. It also reduced annual carbon emissions by nearly 1.7 million kg (3.7 million lb), allowing the mine to claim a tax credit that further reduced operating costs. All of this, according to Cat, was accomplished without noticeable impact on fleet cycle times.

Elsewhere in the white paper, Cat cited the costs of vehicle collisions and incidents caused by lack of visibility, driver fatigue and distraction. It recommended technology such as its Driver Safety System or DSS for alerting both drivers and mine management to potential hazards related to those problems. And, it pointed out, many if not all of the solutions recommended in the white paper are available as features within its MineStar fleet management suite, composed of modules that monitor and manage key mining performance areas such as machine health, machine position tracking, fleet equipment utilization, improved operator visibility and alertness, and autonomous equipment operations.

At Mining Media’s Haulage & Loading 2015 conference in May, representatives from Wenco International Mining Systems pointed out that haul truck refueling ranks as one of the highest-cost activities in day-to-day mining operations—not just because fuel itself is expensive, but also because inefficient fueling policies, such as refueling strictly on a given time schedule or refueling without knowing how much fuel remains in the tank, often lead to lower availability of critical mining equipment. Without proper refueling strategies in place, mines risk removing equipment from production for refueling before it’s actually needed, and in the process spending unnecessary man-hours on refueling that isn’t necessary.

Refueling machines on a rigid schedule, or not knowing how much fuel remains in the tank before refueling, can lead to unnecessary downtime and production loss.Refueling machines on a rigid schedule, or not knowing how much fuel remains in the tank before refueling, can lead to unnecessary downtime and production loss.

Wenco’s Brad Stilley, in a presentation based on a paper by Devon Wells, told the H&L conference audience that Wenco’s Fuel Dispatch, an add-on service to its Wencomine fleet management suite, is designed to provide efficient refueling practices by determining when trucks need fueling and sending them to that assignment only when necessary. Stilley explained that, as a truck dumps its payload, the service polls the vehicle’s OEM fuel sensor to gauge its remaining fuel hours. (For trucks without fuel sensors, the service estimates fuel levels based on model and shift activities.) When trucks need fuel, Fuel Dispatch searches the mine to find the best fueling location for them. Using the Wencomine fleet management system, dispatchers can set all aspects of the service, including target fuel levels, fueling locations, number of queue slots, operating hours and more. Once configured, fueling schedules repeat daily without need of attention from busy dispatchers. Adjustable restrictors prevent trucks from fueling at far away stations, and alerts keep everyone informed about the status of fueling.

As an example of the service’s potential benefits, he pointed to a large oil sands mining operation in Alberta, Canada, with a haulage fleet comprising 61 ultra-class haul trucks, including 34 Caterpillar 797s, 13 Caterpillar 793Bs (excluded from calculations contained in the presentation) and 14 Komatsu 930Es.

In November 2014, the mine began investigating its past fueling data and found reason for concern. During the previous year, the Cat 797 haulers were averaging 12.6 hours between fueling sessions, a tolerable interval—but the Komatsu 930E trucks, without OEM fuel monitors, averaged only 9–10 hours between fuel sessions, which was unacceptable. The mine began using Wenco’s Fuel Dispatch service early in 2015. Under the new system, trucks were dispatched for refueling at the fuel bay that would allow them to be serviced the quickest, using a formula based on travel time, queuing and wait time and actual refueling time needed, by equipment type.

Because the mine closes its fuel bays for two hours, twice a day, remaining-fuel “threshold” calculations were necessary in order to prevent a truck from running out of fuel while the fuel bays are closed. In the initial setup of Fuel Dispatch, the system was configured with a suggested fuel threshold of five hours and a critical fuel threshold of three hours. However, after experience with the system, dispatchers lowered those settings; “suggested” dropped to 3.5 hours and critical to 2 hours.

Given these thresholds, trucks still receive fuel dispatches with 15% to 18% of their fuel tanks remaining—about 1,000 liters for the Caterpillar 797s, which is plenty to perform several haul cycles. Even with these restrictions, though, the producer has extended the time between fueling sessions to 16 hours. In effect, according to Wenco, the mine gains an additional “free” fueling session per every three fuel runs.

With the more efficient refueling setup, the mine’s ultra-class Cat haulers gained about 2.5 more days of production, per truck per year, while the Komatsu fleet did even better, gaining almost a full week of additional production time per truck per year.

Although haul trucks—and the fuel they burn—are big-ticket items, they’re not the only machines in the fleet that can increase costs as a result of diminished efficiency. As Wenco, a subsidiary of Hitachi Construction Machinery, recently noted in a blog post, it’s relatively easy to keep track of trucks and shovels—fleet management tools and OEM systems specialize in analyzing engine hours, cycle times, payload volumes, and dozens of other KPIs. With that data in hand, it’s easy to assign dollar figures for every hour this equipment operates.

Auxiliary equipment, such as dozers, loaders and graders, needs management attention, too. Wenco’s Survey Dozer module, for example, keeps track of the volume of material a dozer pushes during a shift.Auxiliary equipment, such as dozers, loaders and graders, needs management attention, too. Wenco’s Survey Dozer module, for example, keeps track of the volume of material a dozer pushes during a shift.

However, it’s also easy to ignore a mine’s auxiliary equipment such as dozers, scrapers and graders. While managers are closely monitoring the haul cycle, tracking of these behind-the-scenes machines can be overlooked. These units don’t contribute directly to the bottom line. Still, dozers, for example, are essential to a well-run operation, Wenco said—but how can a producer know if any or all are hitting their targets?

A few KPIs can prove a dozer’s worth, Wenco said: travel distance, pushing time, idle times and more. But, the best metric to quantify a dozer’s output is the volume of material it’s moved. Wenco’s Survey Dozer system—one in a suite of related solutions designed to monitor and improve auxiliary equipment performance—tracks a KPI called “dozer push.” Using the mine’s surface designs and readings from the system’s high-precision GNSS sensor, Survey Dozer can calculate the volume of material moved during a shift.

The system works by creating a two-dimensional grid over a defined area of the site. As the dozer passes over a grid square, its GNSS sensor collects the dimensions and elevation of the surface. When the dozer passes over that same grid square again as it cuts and fills, it records the surface’s new dimensions. With each successive pass, the system stores new data on the surface shape and elevation. By comparing the data from each pass, the system is able to calculate a figure for the volume of material moved from that grid square.

Dozer push volumes, according to Wenco, provide a solid benchmark for evaluating equipment work. They enable operators to glean hard numbers from their day-to-day duties. They show mine planners which designs prove most effective, with the least rehandle. They give managers an idea about areas of their mine that need extra attention.

Wenco maintains that, even though dozers aren’t the most obvious equipment to optimize on site, they can still have an enormous impact. Better dozer operation means less rehandle, with less time spent on site clearing and more on production. If a dozer can reshape a bench faster and more accurately, it can save mine thousands of dollars a year. It can move more in less time—by definition, working more efficiently. After all, small improvements done enough times can make a big difference, Wenco said.

Earlier this year, Carlson Software highlighted several new machine control products and updates, including the addition of advanced features and optimizations for its MineGrade and DrillGrade machine guidance systems, plus all new Fleet Manager Office (FMO) ProTools 3-D Viewer and Visual Reporter with dashboard view and timeline view/edit. All are designed to improve accuracy and mine production efficiency.

According to the company, MineGrade 6.1 brings many new improvements to machine guidance software for mining, drilling and other applications. The mine machine control solution supports many machine types used in these applications, including dozers, wheel loaders, drills, shovels, draglines, compactors, cable cranes and haul trucks. New features include performance optimizations, enhanced navigation, new vehicle icons and support, advanced slope calculations, additional sensor support, automatic firmware upgrades, and more.

“MineGrade’s new features are designed to offer higher positioning performance—RTK, heading and slope,” said Randy Noland, vice president of business development for Carlson Machine Control. “And with the new firmware detect and upgrade capabilities, managing larger equipment fleets will become easier and much more comprehensive.”

Carson said its new FMO Visual Reporter Web-based reporting module provides balance between simplicity, accessibility, flexibility, and report automation. This new report generator offers a customizable dashboard view with auto-scrolling that provides real-time metrics at a glance. Its new Timeline View for machine activities provides easy verification as well as a simple and intuitive timeline edit, right in the view.

Reports, which can be easily created, scheduled, and emailed to groups automatically, will include uptime, idle time, dozer pushes, length and count; productivity, distance, and tasks; delays and down codes; and volume per machine and total site volume.

Also new is FMO ProTools v6.1 with new 3-D Visualization, which the company said provides more power and efficiency for production analysis. FMO ProTools v6.1 offers real-time site views and historical playback over larger time samples and is more than 300 times faster than the previous version.

“ProTools v6.1 is designed to crunch data incredibly fast because measuring, analyzing and optimizing production is at the heart of any successful mining operation,” said Noland. “Accurate calculations and easy access to data is paramount.”

Carlson noted that an upgraded engine in FMO ProTools v6.1 facilitates higher accuracy, with smaller grid intervals in order to ease scenario analysis with larger data sets. Additional features enable users to keep the as-built surface for the site up-to-date, follow up-to-date productivity and have full 3-D visualization to see playback of machines over the existing surface.