Haul truck OEMs continue to implement design changes that improve ease of maintenance and minimize technician’s exposure to risk. (Photo: Liebherr)

Coal Age explores how digital technologies are influencing fleet maintenance practices and strategies

By Carly Leonida, European Editor

Maintenance practices for mine haul trucks have come a long way in recent years. While many core tasks, processes and metrics remain unchanged, the now ubiquitous presence of IoT-backed sensors and monitoring systems (many of which are factory fitted) mean that today, technicians have more data at their fingertips than ever before.

OEMs also continue to implement design changes that improve ease of maintenance and minimize technician’s exposure to risk. For example, by adding remote accumulator charging ports or relocating breather systems, so that maintenance tasks can be conducted from ground level or within handrail confines. Components are now fitted with more lifting points and, year on year, there’s continual development of specialized tooling to allow for safer manual handling of machine components than at any time in the past.

“We’ve seen a few trends in truck maintenance in the last 10 years or so,” said Kelly White, product manager – mining trucks, at Liebherr. “The two that stand out are, less time-based component exchange than has been the case in the past, with increased focus on condition monitoring and data analysis. This is resulting in more predictive maintenance strategies. Second, is the need to conduct maintenance tasks safely and with less specialization than has historically been the case.”

Increasingly, skills availability is a key challenge for fleet maintenance and, as such, maintenance tasks are now well documented and more assessment guides available. This allows tasks to be conducted without the need for years of dealer or OEM-specific experience. Maintenance teams are also looking to optimize their capabilities though diversified skills sets and leverage technologies that enable and empower site-based technicians. For example, augmented and virtual reality (AR/VR) technologies are transforming training methodologies, offering risk-free, hands-on experiences for complex maintenance tasks, enhancing learning and execution.

“There’s no quick win to close the gap on skills or their availability,” Joeanne Fox, general manager-customer service at Liebherr Australia, explained. “But leveraging OEM expertise through remote service solutions can improve diagnosis, reduce downtime and support sustainable operations.”

Like many of its peers, Liebherr has developed digital applications to help overcome these challenges. For example, Liebherr Troubleshoot Advisor (TSA) provides access to detailed troubleshooting instructions for common technical problems, enabling mine’s onsite technicians to troubleshoot their equipment as a Liebherr expert would. Available both online and offline, users can follow a step-by-step process to connect to the app, select the problem, and search for solutions.

The Liebherr Content Delivery Portal (CDP) is another. This is a user-centric, intelligent search database comprising all Liebherr Mining technical documentation from operating manuals to assembly instructions, allowing users to locate relevant information quickly and precisely.

“The CDP has several useful functions including an offline mode, smart search, personal collections, bookmarks, document alerts, and more,” Anthony Piggott, remote support manager, Liebherr Group, explained. “Both the Liebherr CDP and TSA help to bridge knowledge gaps by consolidating know-how in a unique location. They also offer easy on-boarding process for new employees on Liebherr equipment.”

Going forward, further integration of IoT and advanced sensors on trucks, providing comprehensive, real-time data, and aiding in early problem detection and efficient maintenance planning will remain a key trend. According to Piggott, advanced remote service platforms that enable efficient remote diagnostics and expert consultations are also likely to feature heavily in future maintenance practices. These streamline the repair process and enhance problem-solving efficiency.

“Utilizing predictive analytics helps in understanding the equipment’s lifecycle, foreseeing potential issues, and planning maintenance strategically, thereby extending the machinery’s lifespan,” said the Piggott. “AI and machine learning (ML) technologies are increasingly indispensable for analysing data to identify potential issues in equipment, allowing for proactive maintenance and preventing larger failures.”

The capability to print spare parts on-site could also prove valuable in time, by reducing waiting times for essential parts, leading to quicker resolution of issues and minimized equipment downtime. And, as the industry shifts towards equipment powered by renewable energy, there’s an increasing need to adapt maintenance practices and skills for these too.

Making Maintenance More Efficient

As the old saying goes ‘knowledge is power’ and it’s not just OEM-specific technologies that are empowering mines to change their maintenance practices. Many sites are finding that third-party engine technologies, for instance, idle management or fuel efficiency systems, and the data they provide can also offer benefits in haul truck maintenance.

Rosco Mining Solutions offers a suite of technologies (Green Fleet Solutions) that improve fleet efficiency, some of which have been found to have a knock-on effect in maintenance. For instance, its Therma Start idle management systems, which are designed for equipment run 24/7 in very cold climates, eliminate unnecessary truck idling by switching off the engine and monitoring critical data points. If a threshold is reached, the computer autonomously starts the engine to protect against loss of starting and frozen assets, maintain battery voltage, air pressure (if air start equipped) and engine temperature.

Today, maintenance technicians have more data at their fingertips than ever before. (Photo: Liebherr)

“Cold weather idling can be really hard on an engine, because the machine cannot produce enough heat to maintain its optimal operating point,” explained Founder and mine maintenance professional, Ross Wert. “There can be a tremendous amount of unburnt fuel which washes out of the cylinders and causes damage inside of the engine. By eliminating idle hours which are not tied to production, you immediately increase asset life while improving maintenance performance metrics and reducing diesel consumption and pollution. We’re fitting these on lots of haul trucks at the moment, including autonomous ones, as most OEMs don’t offer a similar feature.”

Non-productive engine hours have a huge associated cost that often gets overlooked. At first glance, it may only require 50 liters of fuel an hour to idle a 797-haul truck (or similar) but, when taking into account the wear and tear that idling causes on engine and other truck components, that cost can run to thousands of dollars per hour. And for mines that have 30, 40 or 50 trucks or more, that cost can quickly add up.

“The cost per engine hour can be huge, mostly because of all the items tied to engine hours for planned maintenance events,” said Wert. “That’s why idle time is such a critical factor for asset life and operation.”

Another solution is precision fuel flow meters. These are installed to evaluate changing fuel flow conditions and intervene to prevent losses, but they also allow mines to start using fuel consumption as their main maintenance interval metric instead of engine hours. This isn’t practical for every mine, but for some, it can prove more reflective of machine duty than engine hours, and prevents unnecessary maintenance and waste.

Rosco is now coupling data from its Technoton ultra-precise fuel flow meters with GPS location tracking to implement geofencing. For example, by comparing data on fuel consumption and truck location, as well as engine performance stats, like revolutions per minute (RPM), to fleet averages, it’s possible to identify trucks that have, say, low tire pressures or a jammed injector, or even stretches of haul road that need repairing.

There are a plethora of other easily implemented, low-cost devices that are proving their worth in truck maintenance. For instance, almost every haul truck fuel tank is equipped with a feed tube which picks up fuel from the bottom of the tank. Unfortunately, this also means they tend to pick up debris which can load the filters and cause damage to injectors and pumps, decreasing power and fuel efficiency. Rosco sells FuelActive floating fuel pickup devices which have been tested, approved and deployed by Komatsu, Caterpillar and Cummins.

“These devices have proven 92% more efficient in eliminating contaminants from fuel,” Wert explained. “Komatsu installed these on a fleet of 980E haul trucks at a South American mine and the operation was able to push its fuel filter change intervals out from every 250 hours to 1,000 hours.”

Self-cleaning air filters are another. Propulsa air filters monitor engine air intake pressure and, if a drop is detected, an alert is sent to the truck operator to trigger a mini sonic boom — similar to that created by a subwoofer speaker cone — which causes dust to drop off of the air filter and away from the engine. This ensures sufficient air flow to the engine which eliminates loss of power and helps maintain fuel efficiency. Propulsa received the Innovation award from the Quebec association for Road Constructers and Major Works in January 2024.

“A Rio Tinto site in Canada has been using these filters on its haul trucks, wheel loaders and excavators for nearly five years and, in that time, it’s never needed to change an air filter,” said Wert. “Prior to that, they were changing them every four hours.”

SkelStart Capacitors can also be used to replace batteries for starting power, eliminating over half of the batteries in an equipment fleet and providing 100% starting power even at -40°C. This eliminates the need to ever worry about dead batteries.

Putting Truck Maintenance into Perspective

It’s worth remembering that a truck fleet represents one of the most significant capital expenditures (capex) a mining operation will make and, as we’ve seen, the cost to maintain these assets can be significant. It’s therefore important to consider, not only the choice of truck and the technologies each one is fitted with, but also the strategy that’s used for maintenance work.

In a recent blog post, Marc Poualion, industry solutions director, metals and mining at Aspen Technology, explained that traditional preventative maintenance guidelines and programs for haul trucks are usually implemented by mining companies as suggested by OEMs. These are seen as prerequisites for ideal utilization. However, these programs can be expensive to execute and don’t always ensure that optimal equipment utilization is achieved.

“Preventative maintenance can diminish utilization rates, or in some circumstances, create issues where none existed before,” he stated. “Similarly, following the manufacturers’ maintenance schedule does not always ensure that trucks won’t fail. This can lead to unplanned maintenance activities which, at best, can reduce plant productivity and, at worst, can pose a safety risk to operators and other assets.”

Prescriptive maintenance goes beyond preventative maintenance by not only identifying potential issues but providing a specific remedy to address the problem. AspenTech’s prescriptive and predictive maintenance solution, Aspen Mtell, uses the comprehensive monitoring technologies, including proprietary ML technology, to detect potential issues early, inform maintenance decisions, and optimize equipment use, thus decreasing costs and lengthening the life of high capex assets.

“The solution can also identify data patterns, specifically which patterns are demonstrating ‘normal behavior’ within a given system based on historical data,” Poualion said. “Agents are placed in the system to monitor the equipment in real time, capturing all data from the system and when these agents detect behavior that falls outside the established norms, alerts are triggered for certain events that may lead to future failures. With an ability to mark specific warnings as acceptable — the solution provides very few false positives.”

In the article, he explained how one of the world’s largest platinum producers has successfully scaled the solution to over 213 assets across 11 sites globally. The company is seeing material impact in its reliability and predictability by observing alerts that indicate given maintenance activities are required.

Another company deployed an AspenTech solution to assist with analysis of its haul network and machinery to prevent engine failures. Using data from both normal behavior and exact failure patterns in archived engine lube oil samples, agents were created and scaled to nearly 600 engines in the field. Within four months, the ML algorithm detected 10 pending failures and prescribed corrective action with early advance warning.

Moving to Predictive and Prescriptive Practices

Coal Age asked Poualion and Pratibha Pillalamarri, senior product marketing manager at AspenTech, to expand on the use of prescriptive maintenance strategies in the mining sector.

“The mining industry has long focused on preventing equipment failures and ensuring safe operations,” Pillalamarri explained. “While preventative maintenance techniques have been in place for decades, they often fall short, leading to equipment failures despite routine maintenance and substantial expenditures. Condition-based monitoring expanded on this by incorporating vibration analysis, thermography, and oil analysis.

“Predictive and prescriptive maintenance further enhances condition-based maintenance by monitoring and predicting the future performance of equipment. This is made possible by the availability of data and cost-effective sensors that provide crucial information.”

The ultimate goal is to perform maintenance at the most cost-effective point. Breakthroughs in remote connectivity and AI-based analytics in recent years have turned predictive maintenance technology into an effective means of ensuring business continuity and improving overall efficiency across systems, processes, and personnel.

Unplanned outages of either fixed plant or mobile equipment can meaningfully impact a mining operation’s degree of productivity. A haul truck failing during normal operations can be both an unplanned maintenance event and a safety hazard, and the disruption a breakdown causes reduces the confidence with which operations can meet their schedule and jeopardizes operational safety.

“Mining companies are seeing that prescriptive maintenance solutions can mitigate or minimize all of these risks as well as drive down costs,” Poualion added. “Ensuring that fixed plant and mobile equipment maintains the highest levels of productivity and availability will lead mining organizations to superior levels of performance compared to competitors not leveraging this technology.”

Most schedules are based around equipment availability within a given margin of error. Reducing that margin of error by reducing the amount of unplanned downtime and unscheduled maintenance not only leads to increased production given that the equipment will be more reliable than it’s typically planned and expected to be, but also allows mining companies to conduct only truly necessary maintenance activities.

“It will also allow some mining companies to have only the truly necessary number of haul trucks in their fleet,” said Poualion. “If the majority of a haul fleet exhibits the highest levels of reliability, over a consistent timeframe, the operations team will no longer need to have a handful of extra trucks available in case one breaks down. Increased reliability could mean that haul fleet size can be reduced.”

This means that operations and maintenance departments can more accurately and economically plan around an essential fleet, plan for only essential scheduled maintenance and order only the parts that are genuinely required. This allows them to have less capital tied up in back-up trucks and parts that sit on shelves just in case.

Supporting a Prescriptive Strategy

While technology is a key enabler of prescriptive maintenance strategies, successful implementation and execution requires much more… Appropriate organizational structures, processes, change management, and more, are needed to ensure that the shift yields the desired results.

Pillalamarri explained: “To successfully implement a prescriptive maintenance solution, a thoughtful and phased approach is essential. Start by harnessing valuable data sources, including historian data and maintenance data from enterprise asset management (EAM) or computerized maintenance management systems (CMMS). This step is crucial, as information serves as the primary driver in predictive and prescriptive maintenance solutions.”

According to Pillalamarri, driving transformational programs of this nature requires strong leadership and dedicated technical teams. “Securing leadership buy-in and identifying implementation leads upfront are critical steps to ensure commitment and ongoing support,” she explained. “A well-designed value-capture deployment strategy, complemented by a comprehensive communication and management plan, establishes the groundwork for success.”

Vision workshops can play a crucial role in identifying equipment that’s susceptible to frequent unplanned maintenance events or the cause of disruptions in operations. Once predictive failure models are developed, establishing a continuous improvement process allows for the integration of lessons learned and refining the implementation before scaling.

“When the initial deployment is successful, set up a one-year and three-year rollout plan, providing a clear roadmap for sustained success,” Pillalamarri advised. “Tracking key performance metrics and parameters enables the measurement of the prescriptive maintenance strategy’s effectiveness.

“In summary, leverage existing data, select assets meticulously, develop predictive models, and set up continuous improvement plans.”

first zero-hour Thiess

In December 2023, the Thiess Rebuild Centre on Batam Island, Indonesia, completed its first zero-hour truck rebuild. (Photo: Thiess)

Thiess Celebrates First Zero-hour Truck Rebuild

On December 20, 2023, employees at the Thiess Rebuild Centre on Batam Island, Indonesia, celebrated the completion of the centre’s first zero-hour rebuild Cat 789 truck.

Ten Cat 789 haul trucks from Thiess’ Indonesian operations arrived on Batam Island in October, while the facility was being constructed and, less than two months later, the facility was operational, and the first Indonesian truck rebuild successfully completed.

Thiess Group Executive Assets, Technical Services and Technology Ramesh Liyanage congratulated the team for their safe and efficient project delivery and on the significant milestone of the first truck rebuild.

“Our Thiess Rebuild Centre team is a great example of our long-standing expertise in asset management and fleet maintenance,” he said. “This rebuild facility demonstrates how Thiess can leverage our global expertise and come together to solve complex problems. It’s the next step up in the evolution of our capabilities and service offerings.”

Thiess Batam Engineering General Manager, Daryl Albury, said: “The team has successfully reset the usage clock on this truck to zero hours, extending its service life by a further 40,000 to 60,000 hours.

“We have another four 789s stripped back, ready to go through a complete overhaul of all major components, and a full refurbishment of chassis and all electrical systems. Once the first batch of five 789s are completed, they will be shipped across to Thiess’ Australian operations to meet the growing demand for fleet. We look forward to this being the first truck of many over the coming years with a plan to rebuild up to 160 Thiess and third-party trucks
per annum.”