“A frame dump trailer is probably about as simple as it gets,” says Wells. It is very low maintenance. The quarter frame, on the other hand, probably requires the most maintenance. “It has six pivot points that make it work. Every time the body is raising up and down, every one of them is going through some kind of friction.”
A frameless dump trailer also requires more maintenance because there are more moving pivot points. “On a frameless, you have a set of draft arms. You have a center pivot point,” Wells points out.
All dump trailers will perform well if you keep them greased and washed. However, you need to follow a few simple procedures to ensure safe operation.
“When it comes to loading, make sure the load on an end dump is centered from side to side,” says Wells. An off-center load will push the weight to one side or the other when the body is being raised up, increasing the potential for a tipover. “It is hard to get it perfect. But part of the job of the driver is to make sure the loader is putting the load as close to the middle as possible, not just throwing it up there.”
In addition, select the unloading site carefully. “Probably the most important part of the unloading site is choosing a place that is level, where the trailer itself will be level,” Wells emphasizes. “In our experience, we have found that trailer attitude is probably a little more important than truck attitude. While it is important to have both level, if one is really critical, it is going to be the rear end of the trailer.”
The truck and trailer cannot be jackknifed. “It needs to be in line,” says Wells. “That is especially important in a frameless. Because of the way a frameless operates, it pulls the truck toward the trailer in the dump cycle.”
A level, smooth, hard-packed surface is ideal. “But there are times when you must compromise,” Wells acknowledges. “Then you should watch the base. Put the pump into gear and raise the body up. Watch it the entire time to make sure that if it starts to lean, you let it down and reposition the body.” Never move a dump body in the raised position.
Wind speed and direction should also play a role in choosing the best unloading orientation. “A raised trailer is like a big sail on a sailboat,” says Wells. “If you have a 30-mph crosswind, it can blow it over. So wind direction is important. And look above for power lines or any other obstruction.”
Many times, the load does not completely empty. “We recommend the body is lowered and the trailer is pulled up 8 to 10 ft. and then raise the dump body again,” Wells advises. “We know most operators don’t do that, but that is the recommended practice.”
A poorly maintained end dump can also contribute to rollover risks. “The rear hinge is the most important component on a frame dump trailer,” Wells states. As the body gets raised and lowered, all of the weight is transferred from the front to the rear. “At some point, the rear hinge carries almost the entire load. It takes some wear.”
If this component is ignored, that wear will result in slop. This affects dump stability. “If the body is raised up in the air and that rear hinge is loose, 1/16in. movement back there can create a lot of movement when a 30- or 40-ft. body is raised,” Wells points out. “It is very important to keep the slop out of the hinge.”
And even though they should have been have checked during the pre-trip inspection, get out and check tires again at the dump site. “You may have started out okay, but that doesn’t mean you are okay at the dump site,” says Wells. Tire inflation issues can increase the chance of a rollover.