Engineering & Mining Journal

APR 2019

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 40 of 83

DRAGLINE MAINTENANCE APRIL 2019 • E&MJ 39 most every mine, however, can still reap some benefits from improved reliability and performance, even in the short term, with DC upgrade options." With modern computerized mainte- nance management systems (CMMS), it is easier than ever to track direct costs of maintenance and repairs. Couple that with a study of historical data for the cause and duration of both planned and unplanned downtime, a planner can de- velop a very good picture of problem ar- eas to focus on and begin to seek proper solutions, Casson explained. "The cost of unplanned downtime and lost production is almost always the real cost to focus on and far outweighs the direct costs from a maintenance standpoint," Casson said. Depending on the actual upgrade per- formed, the downtime can vary from a few days to several weeks. "Almost all electri- cal upgrades, however, can be performed within a planned shutdown window estab- lished by mechanical maintenance require- ments," Casson said. "The electrical por- tion of a dragline shutdown is almost never the critical path for the total duration." A couple of years ago, Flanders de- veloped a new, complete dragline control platform that can be used for both AC and DC machines. The company is currently partnering with a company that operates multiple draglines to develop adaptive control technology for various portions of the dig cycle. "We are very early in this development, but in cooperation with this end-user and taking a holistic approach to the dragline, we have already identified actionable opportunities to decrease cy- cle time significantly while still protecting the machine," Casson said. Braking Technology Contributes to Efficiency When Rick Kallenborn, North American regional sales manager for Hilliard's mo- tor control division, thinks about aging draglines, his immediate concern is the Cloud Peak Energy installed the first set of synthetic fiber main boom pendants on its Marion 8200 dragline two years ago — with numerous benefits demonstrating a compelling return on investment (ROI), according to Applied Fiber. The first system recently completed the second annual inspection and shows that it is on track to far outpace the life of steel wire in this rigorous application. With both an increase in production and substantial reduction in boom cracking, Cloud Peak Energy has since con- verted two additional draglines to Applied Fiber pendants. The main pendants support the massive boom and loading bucket on dragline. The conversion from steel wire pendants to synthetic fiber pendants has provided numerous financial and operational benefits — attributed to the dramatic weight ad- vantage and dampening characteristics of synthetic fiber. These synthetic main boom pendants are made with Dyneema DM20 fiber, which is seven times stronger than steel wire rope at the same weight, providing exceptional dampening to system move- ment. The highly analyzed and engineered offering nearly mutes normal pendant and boom bouncing, addressing many historical issues with dragline boom fatigue. "This is not just a change of material, from steel wire to synthetic rope. These pendants are a productivity tool and have provided advantages from day one. They have increased capacity of the dragline, reduced the stresses on the overall system, and provided numerous operational and financial returns that were not expected" said Jim Pumphrey, vice president of industrial products for Applied Fiber. Cloud Peak has wasted no time taking advantage of the ben- efits as they have recently outfitted two more draglines in their fleet with fiber main pendants. In fact, they retired a set of steel pendants two years early to realize the gains generated from Applied Fiber pendants. "Cloud Peak predicted and now has validated through actual performance an ROI in less than two years," Pumphrey said. "While no two mines or pieces of equipment are exactly the same, the returns and benefits are quantifiable. We have worked with our customers and industry experts to define the benefits of a conversion to synthetic pendants and developed an ROI calculator for our clients." In addition to reduced maintenance, elements such as increased payload, extended pendant life, de- ferred boom laydown, etc., are all considerations for the ROI calculator and help mine owners, maintenance and production managers make informed decisions." Applied Fiber manufactures the fiber pendants from a spe- cialized production facility, integrating the termination/end-fit- ting technology with a production-testing process to ensure the pendant ropes are perfectly matched in length and tension to carry out this high load, high-cycle application. The test bed is 183 m (600 ft) long and has capability to tension and pre-stress pendants to nearly 950 metric tons or 2-million-lb tension. Cloud Peak Generates Compelling ROI with Synthetic Main Dragline Pendants These synthetic main boom pendants provide better dampening to system movement.

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