>If the ships only carry 4 TEU (or 4 FEU), then lashing is likely not needed if they use Twistloc's welded to a boat deck that is designed for the dynamic loads

>If the ships only carry 4 TEU (or 4 FEU), then lashing is likely not needed if they use Twistloc's welded to a boat deck that is designed for the dynamic loads. With only four containers, I wouldn't even dock/undock the ships; keep them continuously moving, and pick and place the containers dynamically as the boats move through canal lock style controlled conditions. There are Twistloc designs that are purpose-built to automatically work with the container cranes with no manual intervention. on a ocean going vessel you wouldn't need to lash them, no. On a ship this small I would most certainly do. We can probably devise a hypothetical solution for this as well, though. I tried to illustrate (badly) how hyper-efficient modern container operations are. People don't really realize how much work has been put in optimizing all this stuff.