Product Report: Rock solid

Caterpillar’s 770 and 772 and F-Series off-highway trucks incorporate several new features such as engines, radiators, enhanced transmission and brake systems and a redesigned cab for better access. These models are also designed for lower fuel consumption and provide better pass matches with loading machines such as the 385C excavator, or the 980 or 992 wheel loaders.

Caterpillar’s goal was to engineer a series of trucks that increased productivity in the quarry and aggregates industry while reducing the cost per ton.

“We were looking to improve fuel efficiency and offer information systems while providing durability to allow you to get the most out of your business,” says Dave Ellington, Caterpillar’s quarry and construction truck marketing manager. “Most importantly, we know that reducing maintenance costs is important to contractors.”

770 and 772
The 770 replaces the 769D, which was introduced in 1962. The 40.5-ton payload capacity of the 770 is slightly more than the 39.5-ton capacity of the 769, but it also has a slightly lower net horsepower at 476 compared to the 769’s 487. The 772 replaces the 771, which was introduced in 1992. The newer truck has a net horsepower of 535 and reduces the number of engine cylinders from eight to six. Caterpillar increased the body volume by 3.5 percent on the 770 and 14 percent on the 772. The 772 also has 11 percent more payload.

The most obvious physical change on both the 770 and 772 is the positioning of the cab. The trucks’ designers shifted the cab from the left side to the center, improving visibility by allowing the operator to see more positions around the truck. Coupled with this adjustment are mirrors with 52-percent more glass. The cab gains 14 inches and the training seat has been moved to the left side of the operator’s station. The trainer’s seat folds up to provide additional storage space for the operator.

Safety features include three-point operator restraints, electronic lockouts at ground level and additional work lights. The stairs leading to the cab have skid resistant surfaces, toe boards on the platform and easier ways to maintain 3-point contact. An optional camera system provides a view to the rear of the truck through a 7-inch LCD color monitor in the cab. The mirrors and the rear camera combine to give the operator a 115-degree view around the truck.

F-Series
The three F-Series off-highway trucks are replacing older models.

The 773F and 775F are designed for quarry and construction applications in the 60-ton and 70-ton payload classes respectively, replacing the 773E and 775E. The 773F keeps the same 12 engine cylinders as the 773E, but increases net horsepower to 703 from 672 and adds a little bit to its top speed at 41.9 miles per hour, an increase from the 773E’s 40.9 mph. The 775F has a slight bump up in net horsepower at 740 over the 775E’s 730. The 777F is in the 100-ton payload class, and replaces the 777D.

Mike Mesnard, a Caterpillar marketing representative for quarry and construction says that like the 770 and 772, the purpose of many of these redesigns was to make the truck a machine that an operator wants to drive.

“The idea of the roomier cab is that if the operator is more comfortable, then he or she will be more efficient in operating the machine throughout the day.”

Caterpillar provides a variety of body styles for the 773F and 775F. These enable a customer to configure a truck for a specific application and achieve optimum capacity and durability. Like the 770 and 772, dual slope and flat floor body systems with three different steel liner packages and two rubber liner packages are available on the 773F and 775F. The 777F has a rubber liner available in addition to the steel liner offered on the 777D. The size of the F-Series trucks makes it impractical to move the cab to a central position.

Both truck series are also equipped with Caterpillar’s on-board engine oil evacuation and pre-lube system known as QuickEvac, which is designed to reduce oil change labor time by as much as 50 percent.

The standard automatic retarder control controls braking on grade and maintains engine speed. ARC protects the engine from overspeeding, improves fuel efficiency and provides better control of the truck. In addition to the ARC, the compression brake option offers a 35-percent increase in retarding speed capabilities. The F-Series brakes are all hydraulic, rather than air-over-hydraulic. Caterpillar says the result is superior reliability, response, control, serviceability and modulation. The parking brake is integrated into the gear selector for easy operation.