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    1. Earthmoving
    2. Rigid Frame Trucks, Off-Highway

    Hitachi's New Heavy-Weight Contender

    Sept. 28, 2010

    Calling the new EH5000 a "heavyweight" is no stretch of the truth. According to Hitachi, when this new mining truck is fitted with the company's standard heavy-duty body, it has a maximum payload capacity of 351 tons and a rated gross machine weight of 1,164,426 pounds. Actual payload capacity, says Hitachi, can range from 320 to 360 tons, depending on body size and weight, the use of liners, and the specifics of the application.

    The EH5000 has a diesel-electric drive train, and is available with a choice of two 2,700-hp engines, a Detroit Diesel Series 4000 or the Cummins QSK60. An optional version of the Detroit Diesel engine is rated at 3,000 horsepower. The engine powers the truck's Hitachi-Euclid three-phase AC drive system, which the company developed in conjunction with Siemens Industrial Solutions and Services Group.

    According to Hitachi, the AC drive system, which is designed to handle up to 6,000 horsepower when connected to a trolley-assist system, provides the EH5000 with excellent starting rimpull and with the ability to retard movement to "zero speed" without the use of its service brakes. The ability to stop the truck with its dynamic retarder, says the company, greatly extends the life of its rear-axle, wet-disc service brakes. In addition, says Hitachi, the drive system is 2 to 3 percent more fuel-efficient than an equivalent DC system.

    The EH5000's frame is based on the design of the company's R- and EH-Series trucks, but incorporates enhancements in high-stress areas, such as the strut legs and rear axle. The truck also uses new technology for its upper and lower kingpin-spindle bushings. The bushings are made of a copper/nickel/tin alloy, and reportedly, they yield three times the service of aluminum/bronze bushings. Other suspension features, compared to the EH5000's counterparts, include redesigned front-spindle castings and new trailing-arm castings with increased section at the kingpin.