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support equipment Tracks & Treads: Dozers and Loaders Dig into Production Support Roles BY RUSS CARTER, WESTERN FIELD EDITOR The capabilities of bulldozers and wheel loaders are, literally, yards apart. With one designed to push and the other designed to lift, they appear to have little in common. In the mining sector, however, these two types of machines are linked by some mutual characteris- tics: they both fall into the category of support equipment, lending their specialized design strengths to the goal of making life easier for primary production machines such as shovels and trucks; and in mining applications, they rely mostly on power and mass to move large volumes of material, thus posing a challenge to OEMs facing customer expectations for improved economy of operation in each new model. In the simplest terms, you can't move a lot of dirt with- out a lot of machine. Despite the constraints posed by the need for machine mass to move mountains, dozer and loader suppliers continue to find ways to improve fuel economy, reliability, operational flexibility and driver ergonomics. Not only do equipment designs contin- ue to evolve, but the sector itself has seen notable changes in brand ownership as well as the entry of new players in the glob- al market. At the top end of the loader-capacity spectrum, for example, LeTourneau Technologies, builder of the largest pro- duction wheel loader in the world—the 587,800-lb (266 622-kg), 2,300-hp (1715-kW) L2350 'Gen 2'—was acquired by Joy Global in 2011. And more recently LiuGong, a large Chinese construc- tion equipment supplier, acquired a well-known Europe-based dozer manufacturer, seeking increased exposure in a wider market landscape. The new-product stage has been quiet in recent months, as manufacturers hold back on potential rollouts until later this year when MINExpo 2012, the world's largest all-mining equip- ment exposition, draws near. However, mining-class units introduced over the past year or so are, in some cases, making their opening appearance in various market regions. Komatsu, for example, recently shipped the first unit of its updated WA1200-6 wheel loader to go to a North American mining oper- ation. According to Des Jarvis, product marketing manager for Komatsu's mining-class loaders, this machine will be delivered to a Canadian customer. The -6's are built at Komatsu's Ibaraki plant in Japan, which opened in 2007 and is dedicated to pro- duction of large wheeled equipment, mostly for export. The WA1200-6, Komatsu's largest loader, was announced in September 2010 and officially entered the market in early 2011. The new version included improvements such as 26.2-yd3 stan- dard bucket capacity; a new, EPA Tier 2 emissions-compliant diesel, better integration of engine and transmission for perfor- mance and economy; higher reliability of major components; and enhanced operator environment and serviceability. Other notable features included a switch to variable displacement steering pumps for more efficient power management, and the February 2012 Komatsu WA1200-6 loader. standard equipment list was expanded to include a payload meter with register and tracking functions. Service weight for the WA1200-6, at 216,000 kg (476,000 lb) is about 5% more than its predecessor, the WA1200-3. A new boom design provides increased dump clearance, and although its rated breakout force rating is the same as the -3, Komatsu claims the -6 is considerably more stable, with static tipping load rating increasing by several thous-and kilograms. The WA1200-6 also offers signifi- cantly higher air cleaner capacity, along with ground-level service points. Komatsu's wireless VHMS (Vehicle Health Monitoring System) has been renamed Komtrax Plus throughout the product line and is included on the -6, accompanied by a new, more intu- itive operator display inside the cab. The loader is powered by a Komatsu SSDA16B160E-2 diesel, a product of the Komatsu/Cummins Industrial Power Alliance engine joint venture. It is equivalent to the Cummins QSK60 Tier 2 diesel used in other mobile equipment applications. The most recent dozer model from Komatsu is the D375A-6, introduced in 2010 with new technology that enables higher pro- ductivity—in the case of the -6 version, an estimated 8% more than its predecessor. The D375A-6's lockup torque converter feature provides a direct-drive connection between the engine and transmission for more efficient use of engine power, particularly on long passes. For utility dozing in which maximum power isn't necessary, an econo- my work-mode setting reduces engine output to save on fuel con- sumption. For general dozing, the operator can use the transmission's automatic gearshift mode which downshifts on its www.coalage.com 29 Mining requires massive machines, capable of continuous operation in tough The newest loader and dozer models offer performance levels designed to me conditions. et the challenge.