What tool is utilized to fill gaps or voids in the container?

The caulking gun is the appropriate tool for filling gaps or voids in a container because it is specifically designed for applying sealants and fillers in a controlled and efficient manner. When maintaining intermodal containers, it is crucial to ensure that there are no leaks or openings that could allow water, dust, or other contaminants to enter. The caulking gun allows for precise application of materials such as silicone, adhesive, or caulk to seal these gaps, thereby enhancing the integrity of the container and protecting its contents.

In contrast, a ladder is primarily used for accessing higher areas and is not relevant to filling voids. Inspection stands are used to support containers during inspection but do not serve any purpose in sealing or filling gaps. A wire brush is effective for cleaning surfaces but does not apply sealants or fillers. Thus, the use of a caulking gun in this context is essential for ensuring that containers are properly sealed and structurally sound.