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With more than 30 units operating in four countries, the Liebherr R 9400 hydraulic excavators (the latest model in the Liebherr range of mining excavators) achieves new peak values in terms of tons per hour in its service weight category. The 350-metric-ton (mt) R 9400 can be used to load 130- to 150- mt haul trucks. The unit can be equipped in either a backhoe or face shovel configura- tion with a 22-m³ bucket. Either electric- motor or diesel-engine drive can be chosen, making this machine ideally versatile for a wide range of applications. At the design stage, the R 9400's overall efficiency was maximized by increasing the efficiency of each individual sub-system. In addition, routine maintenance for the machine is planned systematically with no unnecessary loss of time, so that the high availability needed for mining work is assured. The production-tailored attach- ment kinematics, combined with a mining- optimized bucket shape, ensure high digging and breakout forces. The R 9400's three-piece heavy-duty undercarriage was constructed to be fatigue resistant and that design also provides effi- cient superstructure weight distribution. Various track pad widths are available to match ground contact pressure to local requirements. Optimizing electrical, mechanical and hydraulic power distribution, the Litronic Plus System allows for easy control even when simultaneous movements are required. The hydraulic cylinders are fitted with the patented Liebherr Electronic Damping System, which provides con- trolled end-cushioning for fast and smooth machine motions. The R 9400 is powered by a Cummins QSK50 diesel engine that complies with the EPA Tier 2 exhaust emission limits and has a rated output of 1,250 kW (1,675 hp). The electric drive version is an efficient alterna- tive if machines are required to operate in arctic conditions or if the mine has its own electric power supply available. The well-equipped cab of the R 9400 is mounted on silent blocks. They reduce vibrations and the level of noise reaching the operator. The cab is of robust steel construction with low stress levels and safety glass windows; it protects the occu- pant against falling objects in accordance with the current safety standards. For extra safety, emergency stop switches are positioned at ground level, in the cab and in the pump and engine compartments for easy access. All routine maintenance points on the R 9400 are easily accessible: the service drop down flap makes it easy to check operating fluid levels and keeps maintenance times short. Jacking System for Slewing Ring Maintenance and Replacement Liebherr also supplies tailor-made ser- vice tools for maintenance work on min- ing excavators and the replacement of hydraulic pumps and cylinders, travel drives or track pads. Optimal working conditions are assured despite the size of these components. The service tools include a pin puller, a hydraulic pump lifting tool, a monitoring system for crawler tracks and their components, and a jacking system. hy d r au l i c e xc avato r s New Developments with Liebherr Hydraulic Excavators With more hydraulic excavators being deployed at mining operations, interest grows in new service systems and GET The Liebherr R 9400 was designed to load 130- to 150-mt haul trucks. 34 www.coalage.com March 2014 The Liebherr jacking system is safer and more efficient than raising the superstructure with a crane. CA_pg34-35_V2_CA_pg46-47 3/12/14 12:22 PM Page 34