The world economy may be slowing down, but the need for infrastructure machinery is holding up. Catching its breath from record sales over the past two years, Liebherr next year plans to keep digging ahead with an updated line of beefier excavators marked for unveiling next spring at the Intermat show in Paris.

Andrew G. Wright / ENR R-926 sports beefier hydraulics for multiple operations.

In October, the closely held manufacturer offered a sneak preview of its new Generation-6 line of crawlers at its factory in Rostock, Germany. All three models—R-906, R-916 and R-926—fit into the 21-tonne to 28-tonne range and come with improved performance ratings. They are powered by Liebherr’s four-cylinder diesel engines, certified to European Union and North American Tier-3 exhaust-emission standards. All are available in standard or “advanced” configurations. Standard includes a “Positive Control” electrohydraulic valve system.

The controller uses sensor-driven logic boards that govern two independent hydraulic loops, offering optimal control during simultaneous operating maneuvers. For instance, the systems maintain flow to the work implement during grading, while the tracks travel in a straight line or a curved trajectory. The advanced package adds a higher operating pressure that gives greater traction along with increased tearout and breakout forces. Both models have received a new hydraulic-hose layout for easier servicing.

A redesigned undercarriage features a new travel-gear design, with a 23-tooth drive sprocket that improves maximum travel speed by 17%, to 6.2 kilometers per hour. Tractive effort is 12% better than on previous models, the company says.

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Liebherr-International New LB-36 drill rig can bore foundation shafts to 3 m in diameter.

Plenty of design changes are topside, too. Engineers improved swing torque and speed by 50% and 24%, effectively reducing cycle times. The advanced model’s cab sports a retractable windshield of shatterproof, double-layer safety glass. The operator will sit on an adjustable, air-sprung seat. Sensors automatically adjust the seat to fit differently sized operators. A 7-in. color monitor works in touch-screen or control-knob mode. An array of sensors on the advance package monitors engine speed for better fuel economy.

Liebherr also showed new production units at its Nenzing, Austria, factory and proving grounds. The company is adding a fifth model, LB-36, to its large-drill lineup. Prototypes were shown at Germany’s Bauma trade fair in 2007. Placed at the top of the Liebherr foundation line with an operating weight of 113.5 tonnes, LB-36 accommodates Kelly-bar drilling down to 60 meters. It accepts continuous-flight augers and double-head drills, and can perform soil mixing.

The new machine, with a 36-m-tonne torque rating, can drill holes to 3 m in diameter. A casing-oscillator tool can operate up to 2 m in diameter. Liebherr’s in-line six-cylinder D-846-A7 engine supplies power to a cable-feed system with a 40-tonne return force. The firm designed the machine and its leader to remain together for transport. A jacking system permits the operator to load the machine onto a trailer once tracks are removed.

Machines are getting smarter, too. All the rigs feature the company’s patented, software-driven “Litronic” control system. “The more frequently the software is used, the greater its reliability,” says Walter Länge, managing director of Liebherr-Werk Nenzing GmbH.