The new 793F Cat Mining Truck, the fifth generation of the 793, builds on the proven, 20-year performance record of its predecessors with a powerful new engine, choice of power train options, choice of body systems and a completely redesigned operator station. These refinements take the 793F—now with 2, 650 horsepower (1976 kW) and a 250-ton (226.8-tonne) payload capacity—to higher standards of productivity, durability, operating ease, altitude capability, fuel efficiency and emissions control.
The Cat 793F also offers enhanced serviceability through its ground level service points and 1, 000-hour hydraulic filter service intervals. Other changes promote safe operator and technician access—wider walkways, flat upper deck, rear access ladder and a three-way lock-out tag-out box mounted on the bumper.
The 16-cylinder, 2, 650-gross-horsepower Cat C175-16 diesel engine displaces 5.3 liters (323 in³) per cylinder—for a total displacement of 85 liters (5, 187 in³). The 793F develops 235 horsepower more than its predecessor, the 793D, which used a 16-cylinder Cat 3516B engine displacing 78 liters (4, 760 in³).
The cross-flow engine design uses four turbochargers, an air-to-air aftercooler and an electronically controlled common-rail fuel system that senses changes in operating conditions and regulates fuel delivery for optimum fuel efficiency. Engine emissions meet EPA Tier 2 requirements. The C175-16, with a 20-percent torque rise, allows the 793F to climb steep grades at productive speeds and to effectively negotiate poor underfoot conditions. The electronically controlled cooling system incorporates a MESABI radiator featuring a flexible-core design that is extremely durable and easy to service.
Drive train options
The Cat 793F electronically controlled six-speed planetary transmission, with an integral lock-up torque converter, drives through the massive rear-axle differential and double reduction final drives, which together provide an overall reduction-ratio of 29:1.
The 793F standard braking system combines three brake functions (primary, secondary and parking) with an automatic, hydraulically actuated retarder operating on all four corners of the truck. These sealed, oil-cooled assemblies use a number of 34.5-inch (874.5-cm) diameter friction discs stacked alternately with same-diameter steel plates. Compressing this assembly with a hydraulically actuated piston (primary braking/retarding) or via spring pressure (secondary/parking brake) slows and stops the truck.
The 793F continues to offer the Additional Retarding option designed for long, steep downhill hauls. This option includes the Extended Life Wheel Stations package and adds a second oil-to-water cooler for brake oil, a second water pump in the brake-cooling system and larger-diameter cooling lines. Equipped with the Additional Retarding option, the 793F typically can negotiate downhill grades one gear higher, compared with trucks having standard brake/retarder assemblies. The higher gear normally allows an approximate 25-percent increase in attainable speed.
The 793F is offered with three body options: X-Body; MSD II (Mine Specific Design); and Gateless Coal Body. The X-Body uses a particularly heavy-duty design and accommodates a larger volume than previous Cat dual-slope or flat-floor bodies—but design enhancements keep the weight of the new body the same as previous bodies. The X-Body is designed primarily for new mine sites, where materials of different densities frequently must be hauled.
The MSD II Body is configured based on an evaluation of parameters at specific sites, including material density, material abrasiveness, impact potential, type of loading tool, haul road conditions and conditions at the loading and dumping sites. The MSD II Body then is custom designed to yield the best balance of payload capacity and durability when working at established mine sites, where material density likely will be consistent.
When hauling coal is the primary task, the Gateless Coal Body can be used to achieve consistently large payloads. The body is designed to retain full loads without the additional weight and complexity of a tailgate. The Gateless Coal Body is designed to be used without liners.
Operator station, machine management and safety
The new F-Series cab features an angled, center-mounted instrument panel and a center console. The cab provides greater viewing area when compared to the previous model. Ergonomic design of controls and displays promotes efficient and comfortable operation. Analog-type gauges are quickly checked without losing sight of the haul road, and the integral Vital Information Management System (a powerful third-generation configuration) provides machine health and payload data, plus easy access to diagnostic and machine management information either onboard or off, via internet-based access.
Levers and switches in the console are comfortably positioned just forward of the right armrest to allow easy control with minimum effort. The fully adjustable air-suspension seat assures all-shift comfort for the operator and is available as an option for the trainer. The newly designed front and side windows give a commanding view of the haul road and work area. A 600-mm-wide (24-in-wide) stairway and walkway, assist safe entry and exit, and wide-angle mirrors, body-raised indicator, double body-retaining cables and reverse-neutralizer (when dumping) further promote safe operation.
For more information about the 793F Mining Truck, contact your local Cat dealer or go to www.cat.com.