High Quality Content by WIKIPEDIA articles! The Caterpillar 797B 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 world-wide. The 797B is the second generation of the 797 series. The 797B was introduced to the public in spring of 2002 and first entered service with a customer in October, 2002. The 797B remained in production until December, 2009 when Caterpillar started full production of the 797B`s successor, the 797F. While it was in production, the 797B was Caterpillar`s largest, highest payload capacity haul truck model.