Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/860257
EquipmentWorld.com | August 2017 39 F or decades, the average size of articulated dump trucks (ADTs or artics) has been creeping up. Where once 24-ton machines were considered the standard size, 35-ton machines are the new benchmark. And the over- 39-ton size category now sports 17 models (see chart). As long as they're properly matched to their loading tools, big- ger trucks deliver bigger production numbers and bring the sure-footed performance of an ADT to larger sites. But often obscured by all the discussion about size is the fact that signifi cant improvements have been made to ADTs of all sizes, improve- ments that also have big effects on production and profi t. Advanced electronics underlie many of these improvements, often in the form of better sensors. One example is the use of inclinometers. An inclinometer, as the name suggests, measures inclines. ADTs use inclinometers to check a truck's angle both front-to-rear and side-to- side. Sensors are also essential to on- board weighing systems, which not only track production but along with inclinometers are key components of systems ensuring safe and effi cient operation. Maryanne Graves, ADT product manager, John Deere, says many im- provements refl ect the fact that ADT operators can be the least experi- enced, least trained of all operators on a work site. "Much work has been done to help these operators be productive and, especially, safe," says Graves. "But experienced operators ap- preciate the safety and production benefi ts of these features as well as the reduction in fatigue they pro- vide." As for size creep, Graves says, "Deere recognizes that while bigger trucks continue to emerge, there's a huge market for smaller trucks on smaller sites, which is why we offer a full complement of features across our line." That line ranges from the 26-ton 260E to the 46-ton 460E. Better drivetrains Most improvements to ADT drive- trains refl ect the demanding con- ditions under which these trucks work. Hill hold-assist keeps the truck in place if it is brought to a full stop on an incline. The feature uses the truck's service brakes, which are released when the operator presses on the throttle. But the brakes are released only when there's suffi cient torque to move the truck forward, thereby preventing rollback. Among the new features on Volvo ADTs are Volvo Dynamic Drive and Dynamic Volvo Engine Brake (VEB) systems. Dynamic Drive matches transmission characteristics to the gradient of the slope and the payload. With Dynamic Drive, the machine will automatically detect when to choose a higher starting gear and when to shift up earlier. Or based on conditions, the truck may hold a lower gear longer, maximiz- ing rimpull. Dynamic Drive can provide a 3- to 10-percent fuel ef- fi ciency improvement, depending on the model. Artics get heavier According to the Equipment World Spec Guide, the number of more-than-39-ton ADT models has almost tripled in 18 years. *Note: The 2017-18 Equipment World Spec Guide & Yearbook will be published in September. 1999 2017 6 models 17 models SIZE