New Gateless Coal Body from Caterpillar Boosts Productivity and Lowers Cost-per-Ton for Cat® 777F Mining Truck

The body and chassis of every Cat® Mining Truck are designed to work together flawlessly as an integrated unit to assure low-cost-per-ton operation with optimal payloads, proper weight distribution, overall durability, safe handling and a smooth ride. Reflecting this precise body/chassis match is the new Gateless Coal Body designed for the 777F Mining Truck. The new coal-specific body significantly enhances 777F performance in coal applications, while eliminating the many disadvantages of bodies that are field-modified to increase capacity.


The new 777F Gateless Coal Body joins a family of coal-specific bodies available for the Cat 785, 789 and 793 Mining Trucks. Multiple body sizes are available for each model, allowing a productive match with any of the various coal densities encountered in worldwide mining operations. These bodies are also available as replacement upgrades for certain prior series models.  As an example, the 777F Gateless Coal Body is compatible with 777D Mining Trucks. The Gateless Coal Body is a precisely engineered alternative to the practice of increasing the capacity of conventional, heavy-duty bodies by adding side-board extensions and after-market tailgates.

The Gateless Coal Body combines a robust understructure-modeled after the successful design of the Cat MSDII (Mine Specific Design) body-with a floor that angles upward toward the rear for nearly two-thirds of the body length. The precise geometry of the long, sloped floor positively retains the load and results in hauling target payloads consistently with minimal spillage. In addition, the relatively low height (compared with many sideboards on field-modified bodies) greatly increases loading efficiency for faster cycles.

The coal-specific design also provides an excellent weight split between the axles, maintaining the designed-in center of gravity, which, in turn, preserves engineered handling characteristics, assures optimum tire life and reduces stress on drive-train components. The Gateless Coal Body also provides the optimum ratio of structural weight to payload capacity-in contrast to field modified bodies, including those using aftermarket tailgates.

To verify the payload potential and weight balance of the 777F Mining Truck fitted with the Gateless Coal Body, Caterpillar conducted a production and load-distribution study with three 777F trucks: one fitted with a conventional heavy-duty body with sideboard extensions; the second with sideboard extensions and an aftermarket tailgate; and the third with a Gateless Coal Body.

The 777F equipped with the Gateless Coal Body consistently carried 25 percent more payload than the truck with sideboards, and 7 percent more than the model with sideboards and tailgate. In addition to higher payloads, the Gateless Coal Body demonstrated ideal weight splits. In contrast, the empty and loaded weight splits of the tailgated truck were significantly rearward.

For more information about the new Gateless Coal Body for the 777F and for other Cat Mining Truck models, customers should contact their local Cat dealer or visit


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