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TRUCKS & SHOVELS 30 E&MJ; • APRIL 2016 www.e-mj.com plement this technology for specifc ap- plications. There is also a lot of interest in platooning for road train line-haul work as well," he noted. Expanding the Lineup Despite the slump in equipment pur- chases, suppliers haven't abandoned product-line expansion and upgrade pro- grams. Last November, for example, Cat- erpillar introduced its 6015B diesel-pow- ered excavator, featuring bucket capacity sized to cater specifcally to applications in small mines, quarries and large earth- moving projects. In February of this year, Hitachi Construction Machinery Americas intro- duced fve electric mining shovels—the EX1900E-6, EX2600E-6, EX3600E-6, EX5600E-6 and EX8000E-6. Bucket ca- pacities for the new models range from 11 m 3 (14 yd 3 ) for the smallest model to 40 m 3 (52 yd 3 ) for the top-of-the-line EX8000E-6. Brian Mace, manager of HCM's mining applications group, told E&MJ; that Hita- chi has offered electric excavators as part of its product line since the mid-90s, but the new models are confgured specifcal- ly for the U.S. and Latin American mar- kets, where electrical power is provided at 60 Hz rather than the 50-Hz frequency common in other parts of the world. Be- cause Canada and Australia impose a par- ticular set of electrical power safety stan- dards on this type of equipment, Hitachi is not quite ready to offer the new series in confgurations eligible for use in those countries. The electric-powered series are iden- tical in most respects to Hitachi's EX-6 series diesel-powered excavators—ex- cept, of course, for the absence of the diesel engine, fuel tanks and air-fltra- tion/muffer systems, which results in the electrical models having an operat- ing weight savings ranging up to 37 tons in the largest model, along with a cor- responding lower ground pressure. The space normally taken up by the diesel models' fuel tanks is used to house the electrical control cabinets in the elec- tric models. The electric shovels also are equipped with a slip ring in the center joint to transmit power to the motor(s). Although the power-handling components on the electric machines are designed to work with either 50- or 60-Hz power, the mechanical gear ratios on the elec- tric versions must be changed to main- tain constant hydraulic pump speed at either frequency. The fve new electric models feature advanced Hitachi TFOA-KK motors de- signed to provide a cost-effective alter- native to diesel-powered machines for mining operations where suitable electric power is available. Motor voltage ranges from 6,600 VAC to 6,900 VAC, providing continuous output rated at 610 kW on the EX1900E-6, up to 1,200 kW x 2 on the EX8000E-6. Mace pointed out that a mine opera- tor's specifc site or project characteris- tics can have a major infuence on which type of machine would be more effective. Greenfeld mine projects for which a re- liable electrical power supply is not yet available would likely not be a good match for electric excavators, while an operation that must comply with local noise or ex- haust-emission restrictions could beneft signifcantly from their use. The need for a trailing power cable might put an electric model at a disad- vantage vs. a diesel-powered unit at an operation that requires the highest level of mobile fexibility from its excavators. On the other hand, electric shovels mod- els simplify daily maintenance—the ma- chines do not require consumables such as engine oil, flters, coolant or fan belts. Engine-related components are also elim- inated, such as radiators, air flters and muffers. Service life of certain compo- nents may be extended due to the elimi- nation of engine-generated heat. As is the case with the diesel versions, the E-6 series electric drive excavator front attachments use welded, low-stress, high-tensile-strength steel for a full box section design that resists twisting and bending forces. The undercarriage for the fve new models is identical to the diesel machines. Swedish truck builder Scania is testing prototypes of its all-wheel-drive, in-pit/over-the-road haulers with driver- less operation, and reports strong interest from Australian mining customers. Inside the cab of Hitachi's new electric-powered excavators, fuid-flled elastic mounts reduce shock and vibra- tion by up to 30%, and an advanced multidisplay monitor provides key machine status information.