1. With a rounded shape, thinner steel gauges can be specified and fewer stiffeners used than with a box shape. The resulting structural optimization also brings a reduction in weight.
  2. It is potentially cheaper to produce, with fewer component parts and less welding.
  3. The contoured body optimizes material centering, reduces carry-back and improves load discharge (see illustration below for load distribution differences between box shape and U-shape designs).
  4. Without stiffeners the center of gravity is lower and the load carried is more stable.
  5. Because a U-shape body is rounded, material does not get stuck in any corners, making clean-up easier.
  6. A larger tailgate opening allows larger stones to be discharged.

Load distribution for a box tipper design (left) and a U-shape tipper design (right).

Exploded illustration of a U-shape tipper with the main components separated.