The containers of a freighter are not simply stacked on top of each other as we have seen. In fact, each of them has fixtures between and between them, locking them together into a single unit.
The loading of containers on the ship is carried in two directions, "in the cabin" and "on deck".
In the cabin, the bottom of the cabin will be designed according to the international standard size of the container to fix the guide trough, and the container can be loaded into the cargo hold along the guide rail according to the placement design when loading.
On deck, the angle parts of the container are used to cooperate with the twist lock and bridge lock. The upper and lower eight corners of the container have a prominent square structure "corner piece", which can carry the weight of the entire container and plays a key role in the process of fixing the box. The corner pieces and twist locks are used to connect the upper and lower containers to ensure that the containers are fixed in the vertical direction. The corner pieces are matched with the bridge lock to connect the adjacent containers on the left and right, keeping them fixed in the horizontal direction. Finally, it was reinforced with lashing rods and all the containers were locked together. So if there is no special accident, it is difficult to drop the container on the ship.