There are six different ways in which ships move in the sea, primarily pitching, heaving and rolling.
Lateral rolling motion represents the greatest challenge for stacks of containers. If containers are to be transported safely on the deck of a container vessel, they must be firmly connected to the ship. This is done with the aid of what are known as twistlocks. These twistlocks are inserted into the corner castings of the containers. These corner castings have elongated holes in which the rotating lug of the twistlock engages, locking the containerstogether. In addition, the bottom two layers of the stacked containers are connected to the ship with lashing rods. Initially, it was common practice to stow stacks of containers on deck in such a way that the individual stacks were connected to each other Continue reading “The securing of containers on deck on a container ship”