High Quality Content by WIKIPEDIA articles! The Caterpillar 797F is an off-highway, ultra class, two-axle, mechanical powertrain haul truck developed and manufactured by Caterpillar Inc. in the United States specifically for high production mining and heavy-duty construction applications worldwide. The 797F is the third, current generation model of the 797 series and is Caterpillar`s largest, highest payload capacity haul truck.