The Caterpillar 789 dump truck is a model of haul trucks, typically used in open pit mining, manufactured by Caterpillar Inc. [1] [2] The 789 has a capacity of 177 tonnes, and its engine can produce 1770 horsepower. While some competing products use hybrid drive, the Caterpillar 789 has an entirely mechanical drive-train. The first Caterpillar ...