Coal Age

JUN 2019

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June 2019 29 shovels and excavators continued cameras positioned at different loca- tions around the machine. The first EX1200-7 excavator in North America was immediately put to work, breaking through 15 feet of concrete-like conglomerate to pro- duce aggregates at a Rango job site in Mesa, Arizona. "We're like a bunch of kids in a candy store," said Dave Johnson, general production super- intendent at Rango. "Especially when the new 1200-7 was delivered. I had multiple operators on other jobs ask- ing when they were going to be able to run it. We were pretty excited." With the evolution of Rango's mining business, there's little pa- tience for equipment that isn't ready to handle the fast pace. Among all the business changes that have occurred, there's one thing that has remained the same: the company's loyalty to Hitachi excavators. As a serial purchaser of Hitachi machines, Rango has had several EX1200-5 and EX1200-6 excavators and were impressed with their pro- ductivity and speed. When the oppor- tunity came to order the new EX1200- 7, it was the clear next step. "Hitachi is our choice as the best excavator on the market," said Dan Mc- Quade, CEO of Rango. "The quality, the cycle times, the production levels, the uptime, and just the overall ease for the operators when they're sitting behind the controls all day, every day. We think they're the best machines out there." The 1200-7 is a versatile machine, McQuade explained. "Whether it's hard digging or soft digging, you know you can configure the bucket so that the horsepower behind the ma- chine, the hydraulics and everything in the design just lets you be the best you can be," McQuade said. "That's why we've stayed with this line and purchased the new Dash-7." Hitachi's EX-7 Series excavators are manufactured in Japan and the EX1200-7 is now be available to the U.S., Canadian, Latin American and Brazilian markets. Liebherr Mining Goes Electric Liebherr offered bauma visitors a unique experience, starting a 200-ton mining excavator live by flipping a gi- ant switch. To achieve this, Liebherr's technical teams had to overcome a huge challenge, routing an electric cable to the excavator that can sup- port the 6,000 volts needed to bring the machine to life, while ensuring an optimal level of safety for the thou- sands of spectators attending the three daily demonstrations. The R 9200 E has been designed to fully support the requirements of the mining industry. With a rated out- put of 850 kW (1,139 HP), the electric 210-metric-ton (mt) R 9200 E balanc- es performance with environmental consciousness. The excavator emits no diesel exhaust and it operates with con- siderably reduced noise. It also boasts a longer engine life cycle and up to 25% less maintenance costs compared to a conventional diesel-powered excava- tor. To reduce starting inrush current, all Liebherr Mining electric excavators are equipped with autotransformer starting devices to avoid disjunctions of the mine's electric network while starting the excavator. Miners work in the most demand- ing conditions and the electric drive has its advantages for them, too, Lieb- herr explained. An electric excavator experiences less power loss than a diesel engine at high altitude and is much easier to start in a cold climate. Liebherr offers a cable-reel option for all electric-drive excavators. This concept offers the machine better mobility, and less manpower is re- quired on site (moving the cable). The cable reel is totally autonomous and has a capacity of 245 m to 300 m de- pending on the excavator type. Some electrically powered hydrau- lic shovels, in face shovel and backhoe configurations, have already achieved 70,000 operating hours without any major maintenance operation on the electric motor. Fitted with a 12.5-m 3 (16.4 yd 3 ) heavy-duty face shovel and patented Liebherr GET to load material with a loose density of 1.65 mt/m 3 , the R 9200 E efficiently loads 65-mt haul trucks in three passes and achieves great cycle times — the fastest mea- sured at less than 20 seconds. Snubber Cuts Maintenance Costs for Rope Shovels Caterpillar recently introduced a new wet-disk snubber upgrade for dipper doors on its 7495 Series electric-rope shovels. The oil-filled snubber is maintenance and adjustment free Liebherr R 9200 E with electric drive loads rock at a test pit in Germany.

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