Liebherr PR 776 Crawler Dozer for Mining and Quarry Operations

The PR 776 is powered by a Liebherr 12-cylinder diesel engine developing 759 horsepower.

It has a maximum operating weight of 74 tons and is equipped with blade capacities of 23.5 cubic yards (semi-U blade) or 28.8 cubic yards (U blade). The infinitely variable hydrostatic travel drive, which is used for all the company’s crawler tractors, is new to this size class, Liebherr says.

Another advantage of this modern drive concept is the optimization of pressure flow. Hydraulic servo 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. The ECO function is standard for all Liebherr Generation 6 crawler tractors, including the PR 776. It allows operators to choose between high performance and maximum efficiency. The ECO control system enables greater travel drive efficiency in light to medium operations, and also provides greater fuel savings, according the company. The proactive power control is another feature: Internal engine and external machine parameters are recorded, such as the current deflection of the joystick. If required, the engine power is automatically increased for a brief period based on the current requirement. As well as responding more rapidly, Liebherr says the machine offers a significant increase in performance potential and pulling power and a higher reverse speed.