After a decade of slow evolution, 2008 marks the advent of revolutionary change in dozer designs. Convention has been placed on the sideline as ?clean sheet? designs have resulted in the introduction of unique solutions to previous limitations. Following is a look at three of the most innovative concepts introduced this year.
Defining a new machine category
This Spring, the John Deere 764 HSD (High-Speed Dozer) took CONEXPO-CON/AGG attendees by surprise. With a profile unlike any dozer currently on the market, the quad rubber-tracked 764 HSD is intended to bridge the gap between a dozer and a motor grader in certain applications.
?It is going to show really well in any application that requires a machine with pushing ability that can work around finished pavement, plus requires mobility on a jobsite,? says Dan Drescher, product market manager - crawlers, John Deere Construction & Forestry. ?If you are targeting primary applications, they would be roadbuilding and large site development.
?[It] is not going to do everything that a motor grader does, nor everything that a dedicated dozer will do,? he admits. ?It will bridge that gap and do a little bit of both.?
There are many utility applications where a small dozer and a motor grader would be under utilized. For example, the 764 HSD could replace a finish dozer and a grader in applications where you are simply finishing up a building pad or a section of road. ?It has the potential on a site to replace some of the machines that are only working part of the time,? says Drescher. ?You can then dedicate those machines to another job where they are working all of the time.?
The unique specifications of the 764 HSD give it advantages in certain applications. With a 22-ft. 5-in.-long base, it is longer than a traditional dozer, enabling faster grading speeds. ?We are able to final grade at up to twice the speed of a steel track machine,? notes Drescher. ?As the technology advances for grade control systems, we will probably exceed that a little bit.?
The length combined with 6.2-psi ground pressure and center-pivot articulation offer some unique operating characteristics. ?It allows you to do some pretty close in and precise work, like fine grade rock in a finish parking lot,? says Drescher. ?It has the flotation of a dozer and the grading ability of a motor grader in that case.? He claims the 764 HSD would actually be more maneuverable than a grader in this situation.
In addition, an 18-mph top speed through its hydrostatic transmission allows the 764 HSD to move quickly across large jobsites. ?Because it does have rubber tracks, you can go across any paved or finished structures without damage to the surfaces,? says Drescher. ?You eliminate the need to either board over the surface or put the equipment on a lowboy and haul it to the end of the site.?
For jobsites that are close together, the 764 HSD can easily be roaded. ?It has turn signals, flashing warning lights and slow-moving vehicle license plate capability,? notes Drescher.
At 200 hp, the 764 HSD is not going to replace a primary scraper tractor. But it is equipped to pull rear-mounted attachments such as sheepsfoot compaction wheels, land planes or smaller pull-type scrapers. ?We have shown it is a real versatile machine with an 11- or 12-yd. dolly wheel scraper,? says Drescher.
The cab-forward design isolates the operator from the drivetrain and provides visibility to the six-way blade. This reduces operator fatigue.
The 764 HSD does have its limitations. It is not well suited to deep cut or virgin dozing, land clearing and rocky soils. It is also less efficient at grading large sections of road compared to a dedicated motor grader. However, in applications where versatility and multiple uses are keys to success, it will provide an attractive solution.
The goal is to increase the utilization rate of all equipment on the jobsite. ?To utilize it right, you are going to be replacing [under-utilized] machines today and also taking advantage of the mobility and high speed,? says Drescher. ?The mobility and speed allow you to just do some jobs a lot quicker.?