Using a Plowtruck for Gravel Road Maintenance
As the snow melts each spring, the challenge of maintaining gravel roads presents itself again. In the last few years many Maine towns have met this challenge by mounting a low cost grading attachment in place of the snowplow on their light to medium duty plowtrucks, taking advantage of the vehicles they are already using for winter road maintenance.
In the past, similar tine rake devices, often called "rock rakes" were towed behind trucks or mounted behind tractors, primarily to clear rocks and debris. By redesigning and strengthening this "rock rake," moving it to the front of the truck and providing a hoist adapter that permits depth control from the operator's seat, the unit has evolved into a more of a grader-rake. It can still perform the functions of a rake with the advantage of clearing debris ahead so that the vehicle does not have to drive over it first. However, it can also smooth and reshape gravel surfaces as a sort of quick and efficient mini-motor grader.
Although the grader-rake is not intended to take the place of a town's motor grader, some towns, especially those with narrow roads, little surfacing material and tight budgets have found this truck mounted attachment to be more serviceable than a grader for some situations. The selectmen's secretary in the little town of Acton, Maine comments that "The boys prefer it (the grader-rake) to the grader. It's faster, cheaper, and does a better job on many of our roads because there is so little material to work with."
Larger towns generally use the grader-rake as a supplement to their motor graders. Starting early in the Spring when the roads are too soft to support a full sized grader, crews use it to restore shape, get rid of springtime ruts and hasten the drying process by aerating the road surface.
Once frost has left the road base and the road is firm enough, crews perform the major reshaping with a motor grader and also pull material from shoulders and ditches into the center of the road. The grader-rake is now used primarily as a rake, separating and removing debris from the gravel that has been reclaimed and finishing that section of road while the grader moves on to another section.
The grader-rake is used throughout the rest of the season to patrol the roads, especially after rainstorms, reworking the damp road surface, repairing washouts and spreading loads of gravel. By tilting and angling the head it so that it pulls material from shoulder to center, the unit can help maintain a good "A" shaped crown Digging Out Potholes: Because the attachment is in front of the vehicle and is pushed into the road surface rather than being pulled out of it like a trailing unit, a significant digging action is created. This forces the tines to scarify and penetrate road surfaces in order to cut out potholes. Because tines are flexible, they are able to spring over hidden obstructions such as buried rocks or ledge, protecting both the attachment and the vehicle.
Although the flexibility of the tines allows increased operating speeds, the truck mounted grader-rake seems to have less of a tendency to bounce than a loader or grader does at these higher speeds. This is apparently because the truck's suspension system absorbs bumps and jolts and the grader/rake is attached to the truck's frame, not its axles.
Another benefit that many towns have discovered is the ability of the grader-rake to plow early and late winter snow storms, before the road surface freezes and especially after it thaws in the spring. Many road commissioners throughout Maine say that the grader-rake is the only means they can use to clear snow from their dirt roads under such soft road conditions.
Because the grader-rake mounts in place of the snowplow on a town's plow truck, it is able to use the existing plow hoist and power angling circuits along with the cab controls for its operation. This has helped make the system easy to use, especially because the operator is always looking forward rather than over his shoulder or in his mirror while he is working. Operators also appreciate being able to work in the warmth and comfort of a truck cab. Finally, because the attachment is mounted directly on the truck, it can remain on the truck during routine patrols, be put to service at any time and be moved at normal travel speeds between work sites.
In areas south of the snow belt where trucks are not normally equipped with plowhoists, several municipalities and government agencies have found it cost effective to add a snowplow package to a utility truck, minus the blade, solely for the purpose of operating a grader-rake.
This article is written By Russ Lanoie, President of Front Runner Corp and the designer of the original truck mounted grader-rake system. The Front Runner is used by many towns and private contractors throughout Maine and the Northeastern U.S. It is presently being tested by the US Forest Service in several parts of the country in and out of the snowbelt on 2 and 4 wheel drive utility trucks.