From the actual practice point of view, there is much, much more to dump trucking and tip-overs, than the above
figures show. Some of the factors that result in tip-over trouble are discussed in the following paragraphs.
The Dumping Site Factor.
a. Fill areas. On embankment type fills, you should stay away from the crest and sides of the fill embankment with
any heavy, dump truck. A heavy crawler bulldozer should be kept on the fill (1) to push the payloads of the dump trucks
over the embankment, (2) to clean up the area of rocks, rubble, and soft spots, and (3) compact the fill area and provide a
continuing firm, level fill surface for the dump trucks to safely dump their payloads. During the dumping cycle, the payload
in the dump body, although diminishing as it spills through the tailgate, puts a brief, abnormally high loading on the rear
axles and tires. Although the fill area looks firm, if there is a soft spot under the surface and one side of the tandem sinks
down more than 7 inches, your dump truck can tip-over on the low side. Backing-up too close to the-edge of the fill, in
order to dump with the least handling of the payload, is also dangerous. If the rear tandem drops more than 19-inches
below the front axle, your dump truck can tip-over backwards down the embankment. On lift-type fills, where dump trucks
are dumping and spreading their payloads on the run, maintain each lift In a smooth, compacted condition with motor
graders and compaction equipment. The dump body, hoisted to its maximum raised position, is unstable and needs a
smooth, rut-free fill area to complete this last part of the payload spreading operation without the risk of a tip-over. Speed
can also contribute to a tip-over condition. The spotters and drivers at the dump area must slow the trucks down,
especially if they observes the dump body swaying in excess of 12-inches during the part of the run at maximum hoist
angle. This is also a sign that more leveling with the grader and more compaction of the fill lift surface is needed. Faster
lift compaction may be gained by routing loaded dump truck traffic over one half of a wide fill, while spreading on the
return run, in lieu of running the trucks empty back over the fill after spreading and turn around. Each loaded dump truck
should be directed by the dump site spotter to follow the previous truck's path, except off-set the distance of the rear dual
tandems, to provide even compaction across the fill. Your loaded dump truck rear dual tandems, with the flat hard rock
tread tires, do an excellent job of compacting fill when the traffic is spaced properly.