What is the primary purpose of a rain gutter in container design?

The primary purpose of a rain gutter in container design is to divert water away from the doorway. This is crucial for preventing water from entering the container when it rains, which can help protect the cargo inside from moisture damage. By channeling rainwater away, the design helps maintain the integrity of the cargo, ensuring it remains dry and suitable for transport and storage.

While structural support is important in the overall design of a container, the specific function of a rain gutter does not relate to providing structural integrity. Similarly, insulation and aerodynamic performance are considerations in container design, but they do not pertain to the function of rain gutters. The rain gutter serves a focused role in managing water drainage, making it essential for preserving the contents of the container against environmental elements.