Closed Box Structural Section Design

Anvil's end dump trailer design makes extensive use of thick walled, closed box structural sections.

Benefits

Even though a round bottom end dump body is already very strong in bending and shear, it is still an open section and thus quite flexible in torsion like any open section component attached to a body. The Ranco Anvil's design has increased the torsion stiffness by using closed box sections in its design. Doing this greatly reduces sideways flexibility or sway. To do this Ranco has:

Welded the entire perimeter of the round body and bulkhead to a thick-wall, box structural member.

Developed fabricated box members for the upper coupler/king pin plate for maximum torsion stiffness.

Fabricated the draft arm from thick-walled, rectangular tubing which is then trussed with rectangular tubing that is set at 45º degree for maximum torsional stiffness - Made the tandem suspension sub-frame of two thick walled, boxed bolsters that wrap around the body and attach directly to the top body-frame tube. These two bolsters are then joined by two large thick walled box sections.

The suspension is then attached to the sub-frame through a thick-walled, boxed pyramid. Each of these closed boxed sections result in maximum torsional stiffness which reduces sideways flexibility and sway.