For corner posts, what is one of the main structural requirements regarding inserts?

The structural integrity of corner posts in dry vans is critical for maintaining the overall strength and stability of the trailer. One of the main requirements is that the inserts used in the corner posts must meet a minimum design strength. This ensures that the corner posts can withstand the stresses and loads imposed during transport, such as tensile strength, compression, and shear forces.

Inserts that do not meet the minimum design strength can compromise the overall effectiveness of the corner posts, potentially leading to structural failures that could jeopardize cargo safety and hinder the durability of the dry van itself. The adherence to this design strength requirement is crucial for ensuring that the trailer performs effectively throughout its operational life, thereby enhancing the reliability of transporting goods.

In contrast, uniformity in size, varying sizes, and the allowance for multiple materials are not as critical as ensuring that the inserts meet specific strength criteria. While these factors may contribute to performance or flexibility in design, they do not address the primary need for structural safety and capability under load, which the minimum design strength requirement does.