Caterpillar recently manufactured and shipped the 500^th 797 large mining truck to a coal mining contractor in Australia. The 797F that marks the milestone represents the third generation of the largest mechanical-drive truck ever built. With 363 t payload capacity, the Cat^® 797 population has grown rapidly in recent years. The first 797 started operational testing in late 1998, and the population in the field grew to 250 in 2007. In the ensuing three years Caterpillar manufactured and delivered another 250 of the model to large mining operations in Australia, North America and South America.

Initially designed with demanding oil sands mining applications as the target, the 797’s breadth of applications also is growing. The Canadian oil sands still host the biggest concentration of 797s, but coal and copper miners are now operating fleets of 797s and iron ore miners soon will be. The largest coal mining operations now use 797s for both overburden and coal haulage. And use them they do – one major Wyoming coal mine in the USA accumulated more than 8,000 hours on a 797B as it hauled more than 11.5 Mt of overburden in 2009. Other 797s in the mine’s fleet also approached that impressive utilisation and production record.

The 797 itself has grown, too. The original 797 model had a nominal payload capacity of 327 t and gross power of 2,535 kW. The 797B, introduced in 2003, has increased gross power of 2,647 kW and nominal payload of 345 t, though target payload grew to nearly 363 t with modifications.  The 797F, introduced commercially just last year, features the Cat C175 engine, which produces gross power of 2,983 kW. The C175-20 that powers the 797F is compact compared to previous 797 engines, and it delivers more power for faster acceleration, faster speed on grade, greater productivity and lower cost per tonne.

Caterpillar manufactured the 500^th 797 and all of its predecessors at its Decatur, Illinois, USA, facilities. The Cat mining truck manufacturing facilities also are growing. To meet increased demand for the 797 and other Cat trucks, Caterpillar announced in June an accelerated capacity expansion plan for the plant. An additional 30% truck manufacturing capacity will come on line at the facility beginning in 2011.