Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/619545
EQUIPMENT MANAGEMENT 34 AGGREGATES MANAGER / January 2016 W e all know the importance of equipment management to minimize production interruptions related to maintenance downtime. How much attention does your operation pay to the management of its heavy equipment tires? Not all tire management, however, directly involves the tires. Other factors in your operations can infl uence tire performance and wear life. Mine design, employee training, equipment modifi cations, servicing deal- ers, and record keeping can also affect productivity and tire performance. Take a look at these factors when putting together or evaluating your tire manage- ment programs. Consider an operation with 100-ton haul trucks equipped with 27.00R49 tires. Each truck's tires, when purchased new, cost between $38,000 and $44,000. This is defi nitely an asset you want to make last as long as possible. Many individuals within your organization contribute to extending or diminishing tire life. Starting with quarry design engineers, considerations to take into account when designing the mine include grades, road crown, road surface, super elevations, and uphill and downhill loads. How do these design features affect the tires? Grades • Steep grades can cause tire slippage resulting in increased tire wear and slower trucks. • Steep grades increase the amount of load transfer to the tires and suspen- sion components. • Load transfer onto front tires in downhill hauls can cause overloading, resulting in increased tire tempera- tures, which is a primary factor in poor tire performance. • Overly steep grades require operators to use multiple transmission shifts to make the climb. These shifts can cause additional shearing forces within tires causing or increasing separations. • The recommended gradient is 6 per- cent. Road crown Road crown is incorporated into haul road designs to disperse water off haul road surfaces, but care should be taken to ensure that all tires are evenly supported by the road surface. Surprisingly, people don't realize how much of an enemy water is to tires. A wet tire cuts eight to 10 times easier than a dry tire. Designers should also take into consideration the type of material used to build and maintain haul roads. Ideal materials compact more fi rmly and resist potholes. Some materials act like marbles, causing slippage of the tires that can slow trucks (production) and cause tread cutting, chipping, and premature wear. A helpful reference for haul road design and maintenance is MSHA's Haul Road Inspection Manual. And, BKT Tires, Inc. and other manufacturers provide off- the-road tire maintenance manuals with other useful information to extend tire life and minimize tire damage. Tire manufacturers and their autho- rized dealers offer a number of services Keys to Extending Tire Life Understand the impact of road surfaces, water, infl ation, and more, as well as how they affect your bottom line.