Originally introduced in 1991, Caterpillar’s model 793 mining truck, one of the company’s largest, is getting another upgrade. Cat, which says it has sold more than 3,000 units of its 250-ton truck, has bumped up the mining truck’s performance, safety and serviceability features. The fifth generation – branded the 793F – features a new engine with more horsepower than that of its predecessor, the 793D, as well as a faster top speed.
Replacing the 2,415-horsepower Cat 3516B engine used in the 793D, Cat’s new C175-16 diesel engine powers the 793F at a horsepower of 2,650. The C175-16, which meets Tier-2 emissions requirements, has a 20 percent torque rise, allowing the 793F to climb steep grades more easily, according to Caterpillar.
“It delivers more power to the ground, which gives the truck more speed on grade,” says David Rea of Caterpillar’s Global Mining division. “The 793F is faster on grade, and because mining trucks spend the majority of their time on grade, it can travel faster, move more tons, and deliver to the customer a lower cost per ton.”
Despite an increase in machine weight to 851,000 or 860,000 pounds depending on body type, top speed has been boosted to 37 miles per hour from the 793D’s 34. On 12 percent grade, the 793F can reach up to 8.5 miles per hour.
For operator and mechanic safety, Cat increased the width of the truck’s walkways; the upper deck is now a single flat level, eliminating tripping hazards; and the ladder access is 600-millimeters wide – 50 percent greater than the industry standard. The 793F also has a three-way lockout/tagout box mounted on the bumper where it’s quickly accessible.
Performance and safety aren’t the only areas of the 793 that have seen improvement. Caterpillar has redesigned the cab, shifting the instrument panel to the middle of the cab to increase visibility, and angling the center console toward the operator’s seat to make manipulating the controls less straining.
“In previous generations of this truck, the way for the operator to hoist the body was to reach down to the floor on the left-hand side and pull a switch down there to raise and lower the body,” Rea says. “We’ve moved that to the center console on the right-hand side at a 45-degree angle.”
“We made the cab quieter inside for the operator, and we are now at 76 dBA. In some applications, we’ve minimized vibration,” he says.
Options on the 793F include an electric-drive-train version, which has a higher top speed than its mechanical-drive counterpart, and fits the needs of contractors that rely mainly on an infrastructure designed for electric-drive machines, Rea says. Also offered is the additional-retarding option, which increases attainable speed and stopping power in steep downhill hauls.
|Spec Comparison: 793D vs. 793F|
|Engine||3516HD EUI||C175-16 ACERT|
|Gross Machine Weight (lb.)||846,000||860,000|
|Top Speed (mph)||34||37|
|Speed on 12% Effective Grade (mph)||7.5||8 – 8.5|