Equipment focus: Talking tread

Tire and rim inspections play key roles in extending tire durability.

A conversation with mining tire experts on tire performance, technology advancements and safety developments.

Tire pressure monitoring. Durability. Selection. Safety.

These are just a few topics Pit & Quarry recently discussed with Roger P. Best, manager of Bridgestone Commercial Solutions’ off-the-road OEM engineering, and Hugo Morales, marketing product manager at Michelin North America Earthmover Tires, in separate Q&As. We’ve combined the two Q&As here for your readability. Read on for their unique perspectives into the world of mining tires.

PQ: Mining tires today are arguably more durable than ever. What factors have driven tire durability to this point, and what else can be done from a manufacturer level to further tire durability even more?

Best: As tires evolve with new designs and optimal patterns that last longer, casing design has had to keep up. If a tread is designed to wear slower than the previous design but the casing will not last, then a new problem is created.

In addition, as new machines come to market with advanced drivetrains that enable the maximum use of the tire’s ability, durability must improve. All of this increase in durability is not possible without maintaining tire pressure. This becomes critical in order to sustain the tire’s ability to do the work.

Morales: The engineering and design that goes into tires today is amazing. The products offered today are leaps and bounds ahead of the tires made just 10 years ago. From unique compounds and formulas to advanced tread designs, tires perform better, last longer and deliver more safety and better fuel economy than ever before. This means that the correct tire selection can add significant tire durability to the bottom line.

Maintenance plays a huge factor on tire durability. Key factors affecting tire durability are air pressure maintenance, driver awareness, tire and rim inspection, haul road maintenance, mechanical equipment maintenance, load management, support equipment to keep roads clear of rocks or other debris that could damage tires, out of service analysis to analyze type of tire damage, and a tire performance improvement committee to generate clear and specific policies and reports of all the initiatives and progress made in any meetings.

PQ: What role does tire pressure monitoring specifically play in creating safer working environments, and how is technology improving an aggregate producer’s ability to monitor tire pressure?

Morales: Michelin recommends the use of a TPMS (tire pressure monitoring system) to monitor the temperature and pressure of the tires. The system must provide real-time feedback to the dispatch and tire shop to allow them to be proactive in correcting the pressure and/or change the route of the haul truck.

There has been an increased demand to improve productivity and reduce operating costs in a suppressed economy. The goal is to do more with less. The TPMS system is a good tool that can be used to maximize the TKPH (ton kilometer per hour) in real time, as mine site conditions change. The mine operators can be proactive to make changes to loads, speeds and length of runs.

Best: Tire pressure monitoring has come a very long way in the past few years, including monitoring systems that measure pressure and temperature. These advanced systems allow the customer to know the internal temperature and pressure of the tire.

This information, used with the correct analysis software, can help the customer decide when to stop the machine for adjustments and to check tires for abnormal conditions. Another advantage is that the system offers real-time information so pressure adjustments only need to be done to the tires that need it. This alone may save a customer about 3 percent in uptime usage, on average.

If a tire is getting hot, the system can alert the driver or manager that the tire needs to be inspected. This could save the loss of the tire or even prevent damage to the machine. But safety is the real winner. There are inherent dangers in running on over- or underinflated tires and on tires that are overheating. Incorporating a monitoring system into your operations may make them safer.

PQ: Let’s discuss the role of tire selection: Why is selecting the right tire so important and what are aggregate producers losing or risking by not selecting the proper tire for the right machine?

Best: Total cost is critical in the selection of tires. Without the proper tire for the application it is possible that the cost per hour of that tire will be higher. You may pay more in the long run by selecting the wrong tire for a specific application. The proper tire may also have effects on machine efficiency and productivity.

A great starting point for any customer is to implement a program to track the performance of their tires. A reputable servicing dealer is also a key part to this selection process. The dealer should partner with a manufacturer in order to provide the customer with critical knowledge of the products. A site visit from the manufacturer representative can also help in determining the correct type of tire and proper air pressure for the application. The dealer can also help by offering services such as tracking, repair and retread.

Morales: Selecting tires for your operation, whether they are replacement or original equipment, can be challenging with all of the available choices. Purchasing tires should be me made with emphasis put on the operation, equipment, productivity, maintenance practices and total cost of ownership. Making an educated selection for a specific situation is the key. The most important criteria in selecting a tire when ordering new equipment or choosing a replacement tire is to determine what the specific equipment does or is required to do on a regular basis.

A tire designed for low-speed, off-road applications may experience internal damage from heat if it runs at high speeds. If replacing the tires, what is the current size and inflation pressure? Has there been satisfaction with the existing tire’s traction, wear and performance? In many instances, customers who compare their current set of tires with their current needs find that a change may be in order. The proper selection can prevent expensive downtime. Selecting a tire with the steel protective plies can provide a significant improvement in shielding the tire against aggressions and separations. Selecting a tire with a premium sidewall can provide twice the protection to resist cuts and abrasions.

Advanced tread designs have helped tires perform better, last longer and deliver more safety and better fuel economy than ever before.

PQ: According to MSHA, nine miners were killed in tire accidents between 1998 and 2011. In 2012, MSHA reported three employees were seriously injured when a front-end loader tire ruptured while being inflated. What are the biggest safety hazards related to tires that exist today in pits and quarries, and how would you advise aggregate producers to minimize these risks?

Morales: Safety risks still exist today. With the sometimes rates of turnover with tire service providers and tire related employees at the sites, the biggest risk still remains lack of substantive training. Continuous improvement with respect to basic tire awareness and training need to be on the forefront of service providers and sites’ practices. Those best practices range from tire science to air pressure maintenance fundamentals, which is the foundation for a functional and safe tire program.

Best: The biggest focus is on training. At Bridgestone we start every day with a safety share message. It is ideal that our customers follow these same practices used in the industry to keep people safe.

PQ: Without the aid of a modern tire pressure monitoring system, how else would you advise aggregate producers to successfully keep an eye on tire pressure? How often should they do checks on haul trucks, loading equipment and other regularly used equipment that’s wheeled?

Best: In our opinion, every operator should conduct a pre-trip inspection of their machine, including tire and wheel checks. The check might include checking tire pressure and recording the figures. Ideally, the equipment should be checked at least once a week for cold pressure. The information should be documented so the customer can track issues with tires if a problem should develop.

Morales: All tires should be kept at the pressure specified by the tire and vehicle manufacturers. The correct tire pressure for a radial tire will vary widely depending on the machine type, manufacturer model type and weight. It is always a good idea to consult the tire manufacturer to ensure that each axle is properly weighed and the correct pressure is set.

Any vehicle with properly inflated radial tires carries its load in a noticeably different way. Radial tire technology separates the work done by the sidewall and tread areas, allowing the tire to conform to the terrain by running at lower air pressures than bias tires. This lower air pressure yields a more even footprint and higher levels of traction for radial tires. The constant footprint ensures that the lugs strike the contact patch simultaneously, reducing vehicle vibration.

Because the operators are onsite all the time, they see problems that need to be fixed, whether it’s in their pre-trip inspection or while operating the equipment. Managers and supervisors can draw their operators into the equation by asking for input and cultivating a team approach to tire and vehicle maintenance. Operators should be kept in the loop on situations with their equipment or tires so they are aware when they conduct inspections or operate the equipment.

It is crucial that operators report any spillage, whether from their vehicles or other vehicles.

PQ: From your vantage point, what will be the primary method of monitoring tire pressure and temperature 10 years from now?

Morales: TPMS systems will play a key role to monitor the temperature and pressure of the tires. The system must provide real-time feedback to the dispatch and tire shop to allow them to be proactive in correcting the pressure and/or change the route of the haul truck. New technology may be out there in 10 years that may change this, but for now the most accurate way to monitor air pressure and temperature of tires is the TPMS.

Best: Original equipment manufacturers have started to outfit machines with pressure monitoring systems. As the technology improves and more OEMs add systems to their equipment, we suspect tire pressure monitoring will be standard or perhaps optional on off-road industrial vehicles just as on your automobile.

Photo: Michelin North America Earthmover Tires