Liebherr extends its crawler tractor generation 6 downwards – model premiere of the PR 726 at NordBau 2015 trade fair

The new Liebherr PR 726 crawler tractor will have its world debut in September at the NordBau building industry trade fair in Neumünster. The model is the successor to the successful PR 724. The official start of sales will be early 2016.

The new Liebherr PR 726 Litronic crawler tractor offers an operating weight of 16,000 kg to 19,800 kg and its Liebherr diesel engine returns 120 kW / 163 HP.

The PR 726 is powered by a 4-cylinder Liebherr diesel engine that complies with the Stage IV / Tier 4f emissions standard. In order for the requisite emissions and consumption targets to be achieved, the entire combustion process has been optimised to reduce the particulates, even within the engine, to a minimum.

To simplify the system and to optimise exhaust gas treatment, Liebherr relies on selective catalytic reduction (SCR) technology for the PR 726. This makes the use of a diesel particulate filter unnecessary and thereby simplifies maintenance for the customer. The highly efficient combustion process facilitates low fuel consumption.

The optimised adaptation of the engine parameters to changing operating conditions is supported in a number of ways including an in-house-developed common rail injection system incorporating an in-house-developed electronic engine management system.

The main components of the generation 6 crawler tractors come from Liebherr's own production line and are therefore optimally tailored to the machine. Among these components are the diesel engine and the common rail injection system as well as the electronic components and various hydraulic components. Here, Liebherr can draw on over 50 years of experience in the development of crawler tractors.

Highest performance and operating efficiency

As with all generation 6 tractors, the new PR 726 Litronic also features an electronically-controlled drive management system with integrated ECO function. This makes it possible for the operator to select between high performance and maximum economy. The ECO control system here enables even greater travel drive efficiency in light to medium-duty operations.

The proactive power control is another 6th generation innovation. This involves the detection of various machine parameters and if required results in an automatic increase of the engine output. As well as responding more rapidly, the machines offer a tangible increase in pushing performance and dynamic response.

This hydrostatic drive keeps the engine speed at a constant level. All drive train components and the intelligent Liebherr engine management are optimally adapted to this speed, which makes a significant contribution to reduced fuel consumption.

The combined inching brake pedal facilitates the transition from conventionally driven machines to Liebherr generation 6 crawler tractors. With this equipment option, both the travel speed and the brake can be controlled via the foot pedal. A key enhancement is the 3-stage joystick (which can be locked in forward, stop and reverse), which is also available as an option.

The PR 726 offers exceptional smooth running and perfect crawling properties. Long-running gear systems, an effective balance and optimal visibility are superior features for precise levelling, irrespective of whether this is done manually or using automatic grading systems.

The PR 726 offers exceptional smooth running and perfect fine grading properties. Long undercarriages, an effective balance and best visibility are prerequisites for precise finish grading, irrespective of whether this is done manually or using automatic grading systems.

Plug-and-play: easy installation of machine control units

For simple and trouble-free implementation of automatic machine control units, Liebherr also offers factory-fitted preparation kits for generation 6 crawler tractors, which are available for the systems of well-known manufacturers such as Trimble, Topcon or Leica.

Whether the machine operator opts for a 2D or 3D control system for the intended deployment, both laser and GPS systems or controls with total station can be used without problem on the same machine. This makes the installation easier and offers the owner the highest level of flexibility in the selection of their system.

If required by the project conditions, an individual machine control system can be used consecutively on different Liebherr crawler tractors that are factory prepared resulting in considerably lower investment costs for the operator.

Liebherr works intensively with the manufacturers of control systems both in the area of development and after sales and thereby ensures that the user always receives the best service from their chosen supplier.

Equipment for any application

The new PR 726 Litronic's performance is made complete through its comprehensive range of equipment. This starts at the front with a universal 6-way blade, with folding corners as an option for easy transport, extending through to a straight blade and semi-U blade for moving larger quantities of material. To further simplify machine transportation, a semi-U blade with an overall width of 3 metres for a track width of up to 610 mm is also available.

At the rear, 3-shank and 5-shank rippers can be chosen as well as, for example, a hydraulic rope winch, counterweight or drawbar.

Based on the extensive experience of material handling operations that Liebherr has gained with its large dozers, the new PR 726 Litronic can also be configured for industrial applications such as handling of coal or wood chippings.

The new PR 726 will also be offered in a special dozer version for landfill sites, adding to the extensive range of Liebherr machines for this target group. Special equipment features make this model the ideal system solution for this challenging field of application and include, for example, a pressurized cab, special seals in the cab and engine area, protective devices and covers, optional reversible fans and special landfill blades with trash tracks or striker bars.

Modern design and comfortable new cab

The modern design of the new generation 6 crawler tractors, with sloping edges on all sides and panoramic windows, offers the operator an optimum all-round view of the terrain as well as the blade and rear ripper. The view over the engine hood is completely clear as the exhaust stack and lifting cylinders have been positioned behind the A-posts. A good all-round view enhances efficiency and improves safety.

Numerous innovations in the cab area of the larger generation 6 machines have now filtered down into the compact class. The travel and operation joysticks make ergonomically safe handling possible thanks to the new T-shape. The required travelling speed range can be preselected directly on the joystick enabling control of the tractor to be selected precisely, especially at low speed. Driver detection takes place automatically by means of the integrated seat contact switch without a safety lever having to be activated.

The touch-sensitive system display for Liebherr earthmoving machines is also featured on the new PR 726 Litronic. This enables important operating parameters, such as the ECO function or the travel drive response and steering, to be adjusted intuitively and with a clear overview.

For optimum illumination of the working area, halogen headlights or high-performance LEDs are used depending on the chosen equipment level.

Easy maintenance, low operating costs, optimum planning reliability

Centralised servicing points, wide opening access flaps and engine compartment doors, an operator cab that tilts as standard and fans that fold out for cleaning (optional) facilitate perfect service access and simplify the maintenance process.

Depending on the application, and provided that regular quality checks are performed, the hydraulic fluid change interval can be as long as 8,000 hours of operation. Compared with the previous model, the maintenance intervals of the diesel engine in the PR 726 have been doubled to 2,000 operating hours, which overall results in reduced operating costs.

The PR 726 Litronic’s undercarriage is a completely new development. The segmented sprocket has a larger diameter with more teeth so that the operating life of the bushings and sprockets is extended. The Liebherr FTB undercarriage is also available as an option for the PR 726. This swivel undercarriage with rotating bushings, exclusively developed for Liebherr, is particularly well-suited for work on soft, abrasive ground and considerably extends the service life in sand, for example. If used in areas with impact loads, such as on stones and rocks, the trusted lubricated-for-life tracks are the ideal solution. Both undercarriage versions can be retro-fitted retroactively.

As with all previous generation 6 models, the PR 726 features a 3 year / 5,000 hr warranty on the whole drivetrain as standard and without charge. In addition, Liebherr offers special guarantees as well as tailored inspection and service programmes. This enables maintenance checks to be optimally scheduled giving customers reassurance across the whole service life of the machine.

Information about all machine data anywhere, at any time

LiDAT, the data transfer and positioning system from Liebherr, supplies information, for example, machine location, operating and utilisation times, fuel consumption as well as service interval information. This gives the fleet operator the ability to schedule service and maintenance more effectively.

Technicians can be sent out and spare parts planned more optimally. As such a significant cost saving can be achieved while, at the same time, improving machine availability. LiDAT data can also be used to calculate hire rates.

The LiDAT data can be accessed via GPRS or data carrier. As just a web browser is required to use LiDAT, information can be made readily available on a variety of end-user devices.

Additional security is offered by an automatic alarm function, which can be set up for particularly important information, for example. notification of critical operating conditions or a machine leaving a predetermined zone or being operated outside authorised hours.