Material sticking to the inside of dump beds during tipping is a nagging problem for drivers in Manlius Township, Ill., but not for a truck equipped with a certain electric vibration device.

It’s been a year since a Cougar DC-3200 from Martin Engineering was attached to the dump body on one of the small municipality’s three trucks. Says Road Commissioner Rob Allen, “I love it.”

The single-rear-axle trucks have plow attachments and 7-yard boxes. They are dispatched to various jobs throughout the township, located southwest of Chicago.

“We use our dump trucks for all kinds of jobs, from public works projects to winter road maintenance,” Allen says. “Each project has its unique problems, but one issue we had across all of them was material sticking to the truck beds.”

Drivers normally have to jolt the beds with abrupt vehicle movements or climb into the bodies with shovels to dislodge gravel, rock salt and dirt. It can take an hour to complete offloading, and the stuff sometimes isn’t deposited as desired. Gravel spread on a road comes out lumpy, and it takes a motor grader as many as six passes to smooth it out.

Loads using the vibrator, however, pour out faster and more evenly, reducing grading time and providing a smooth path for motorists. The truck can handle four to five more runs per day, there’s less strain on equipment, and the driver is safer.

Effective dislodging allows Allen to use a heavy mix of salt and rolled slag from a nearby steel mill for ice control. “A single-axle dump is not as stable as a tandem axle,” he says, “but now I can raise it half the height that I used to,” thanks to the vibrator-induced offloading. That reduces chances for rollovers.

Another truck has a vibrator from a different manufacturer, but it doesn’t work as well, Allen says. The third truck lacks a device, but he plans to buy one for it this summer.

“I’ve been around vibrators for quite some time,” Allen says. “I tried to make some myself. When they work, they’re great. But when they don’t, you’re back to where you were.”