Decatur, Ill.— Caterpillar recently produced its 5,000th mining truck — the 380-ton-capacity 797B. Caterpillar reached the milestone only 20 years after producing its first large mining truck — defined by Caterpillar as those models with a payload capacity of 130 tons or more.

Caterpillar now offers four large mining truck base-models. All four models are produced in the Decatur manufacturing plant. The approximately 2,000 employees of the plant also produce motor graders, wheel tractor scrapers, quarry and construction trucks, and mining excavators.

Caterpillar's first large mining truck, the 785, with original capacity of 130 tons, was introduced in 1984 and was an immediate success. Building on that success, Caterpillar introduced the 170- to 195-ton-capacity 789 in 1986. Within two years, each of the two models became the leader in the size class, and in 1996 sales grew to nearly half of the worldwide market.

In response to mining companies seeking lower cost per ton, Caterpillar introduced the 240-ton-capacity 793 mining truck in 1991. Two years later, production of the three mining truck models reached the 1,500 milestone.

Subsequently, larger mining shovels created an opportunity for ultra-class mining trucks to help lower costs in large mining operations. Caterpillar responded by introducing the 797 in 1998. The original 797 carried a payload of 360 tons, making it the largest mechanical-drive truck in the world.

The expanded line of four mining trucks has helped Caterpillar lead the market as approximately 3,500 of the machines have been produced and sold during the past 10 years. Of course, all four models have been improved through the use of new technology during that span. The most recent versions are designated the 785C, 789C, 793C, and 797B. The product line also includes the 784C tractor that has a hitch system for pulling a trailer.

The 797B that marks number 5,000 will join a fleet of 797s in the Escondida copper mine, which produces more copper than any other mine in the world. Located in Antofagasta Province in northern Chile, Minera Escondida moves more than 350 million tons of material per year and is ramping up to full production capacity of more than 1.3 million tons of copper concentrate and cathode annually. The mine currently accounts for about 8 percent of worldwide copper production.