Since its market launch in 2016 as the world’s largest dozer with hydrostatic drive, the Liebherr PR 776 has exceeded customer expectations in productivity, efficiency and safety, its manufacturer says. Whether it is heavy-duty ripping, grading or other duties, the PR 776 is designed to accomplish them all.

With the PR 766 G8 introduced at the beginning of 2021 and the smaller PR 756 G8, Liebherr now offers a fleet of dozers, ranging from 78,044 to 161,354 pounds of operating weight for tough construction and mining operations.

To further boost use of the machines, while also improving safety, comfort and productivity, customers can tele-operate their machine with Liebherr Remote Control (LiReCon). 

During a recent Customer Appreciation Day at its Newport News, Virginia headquarters, Liebherr USA added the PR 776 dozer and several other machines to its available lineup in North America.

The PR 776 is the only mining dozer said to feature an infinitely variable hydrostatic travel drive. Powered by a Liebherr 12-cylinder, 768-horsepower diesel engine, the PR 776 allows operators to choose between high performance and maximum efficiency via the Eco control system, which enables greater travel drive efficiency in light to medium operations and provides greater fuel savings.

One advantage of the drive concept, according to the company, is the optimization of pressure flow. Hydraulic pressure is based on-demand according to the task. If, for example, the full feed of pressure supply is not required when operating, this is automatically returned. A product manager said the high drive also prevents extra wear on the sprocket teeth because it's not digging in the dirt all the time and requires less horsepower for the same reason.

Liebherr says if required, the engine power is automatically increased for a brief period based on the current requirement. As well as responding more rapidly, the machines offer a significant increase in performance potential and pulling power and a higher reverse speed.

Another key advantage of hydrostatically powered crawler tractors or dozers when working in restricted spaces is the excellent maneuverability with continuous power to both tracks. All steering motions, including turning on the spot, are fast and precise. When involved in ripping work, the ripper can be positioned precisely to enable it to apply power when ripping layers of hard rock.

The cab of the PR 776 is designed for comfort, convenience and simplicity with single joystick operation. The cab noise level is rated at 76 decibels. 

The multifunction joystick houses all operating and steering movements at the palm of the hand with only one electronic input element. This operating concept was subjected to rigorous testing at Liebherr and is an important innovation for the 70-metric-ton dozer category, particularly in mining applications, the company says. Operators can quickly find their bearings in the PR776 platform.

All instruments and operating controls within the cab are carefully organized for easy reach. Key functions and machine settings can be adjusted by the operator via the touchscreen display. Eco function parameters, automatic engine speed reduction, travel drive response, steering as well as standard safety functions such as the rearview camera can be all be accessed through the intuitive touchscreen display.