What indicates a valid downward deformation for the rear sill?

Choosing the option indicating that downward deformation of the rear sill should not surpass the lower surfaces of the corner fitting is correct because this is a crucial standard in maintaining the structural integrity and functionality of the dry van. The rear sill is an important component as it helps distribute weight and provides a proper seal when doors are closed.

If the deformation exceeds the lower surfaces of the corner fittings, it can compromise the van’s ability to close properly, potentially allowing moisture or contaminants to enter. Furthermore, excessive deformation can lead to additional stresses on the overall structure, affecting performance and durability. Maintaining this specific standard helps ensure that the dry van can withstand various loading conditions while minimizing the risk of damage and ensuring safety during transport.

Other options may not provide the necessary structural guidelines or reinforce the importance of keeping the deformations within defined limits, which is essential for effective operation.