CATERPILLAR INC. [CAT-NYSE] recently added two new models to its line of large mining trucks with electric drives – the 326-tonne 796 AC and the 373-tonne 798 AC heavy hauler.
Caterpillar said, in a November news release, that the additional haul trucks expands its mining truck offering, “to give mining companies the flexibility to choose what meets their needs and preferences.” The company successfully introduced the 794 AC 291-tonne (320-ton) capacity truck at MINExpo 2016 and investments to further advance the 797F 363-tonne (400-ton) mechanical-drive truck.
According to the news release, “The new electric-drive 798 AC features a 372-tonne (410-ton) payload and will join the fleet of over 1,000 Cat® mechanical-drive 797s in the 400-short-ton class. The new electric-drive 796 AC delivers 326-tonne (360-ton) payload and will be offered in all regions. The 795F AC, in the same size class, will continue to be offered in regions where engine emissions are less regulated. Both trucks will be available in second quarter 2019.”
Caterpillar explained that the design of the new trucks focuses on delivering class-leading payload, high reliability and simple serviceability. The company said, “These attributes are built on the frame and chassis design proven in 18 million hours of legacy truck operation and now used by the Cat 794 AC.
“The AC powertrain of each of the two new trucks draws from about 5 million hours of Cat 795 AC and Cat 794 AC truck operation. Cat AC electric drive is developed and manufactured by Caterpillar, the single source for the entire powertrain.”
Powering both trucks is the Cat C175-16 diesel engine. Caterpillar explains that “The engine has proved itself over more than 21 million hours of operation in mobile equipment and power generation, the reliable engine can be configured to meet US EPA Tier 4 emissions regulations and offers a choice of 2610 kW (3,500 hp) or 2312 kW (3,100 hp) to meet the mine’s needs. To further adapt to the mine, simple software changes can adjust system power to help meet production targets or to work smoothly in mixed fleets.”
Caterpillar goes on to say, “The 796 AC and 798 AC are built for efficient production. Both truck models are designed to minimize empty machine weight, as configured in the field. The design enables the 798 AC to carry its class-leading payload of 372 tonnes (410 tons) and to haul more material each cycle on 59/80R63 tires.”
The new trucks feature four-corner, oil-cooled disc brakes as well as dynamic retarding for stable handling and confident stopping. Superior retarding capability, blended braking and the Cat Traction Control System help boost productivity while enhancing safety.
The Cat AC drive is a high voltage system (2,600 volts) that operates at lower current than the most other competition. When combined with Cat’s total integration and design of the truck and drive system the result is higher efficiency, lower heat generation, smaller and lighter components, and longer component life.
The Cat High Efficiency (HE) Body is sized and configured to meet the specific needs of the mine, dictated by fragmentation, abrasion, cohesion and the loading tool. The curved floor, front, and canopy strengthen the entire body, which is integral to the truck. The body is sized to meet the payload requirements without compromising vehicle balance, braking or control.
According to Caterpillar’s press release, “Open engine access and service platforms ease maintenance tasks. The modular design allows for easy removal and installation of components. The engine, traction alternator, motors, inverter, grid and final drives can be removed independently. Traction alternator and optional inverter platforms allow for easier inspections, diagnostics and component swaps. The result is less service time and greater uptime.”