How Containers are Loaded on a Full Container Ship
By: Michele Marinelli
Sometimes, customers ask us to have the steamship line load containers on a ship’s deck, or on top of all other containers to avoid risking cargo being squeezed and damaged due to collective container weight. Unfortunately, these requests are out of our control.
In this article, you will learn how containers are loaded onto vessels, what types of parameters and constraints there are when loading, and why there is such a specific loading process.
Overview of the structure of a container ship.
Every stowage takes the structure of the ship into account. Thinking about the ship as the “container” where the objects must be inserted, it is clear that its shape, size and load capacity are the first pieces of data necessary to solve the stowage puzzle.
The below figure shows the structure of a full container ship, through a horizontal and vertical cross section. We can see that each cross-section of the ship, or bay, is made up of a fixed number of locations, called cells, of measurement and number varying according to the ship’s configuration. Each cell is identified by three indices, each consisting of two digits, which give it its position in three dimensions, in particular:
- Bays: Identify the position of the cell relative to the cross section of the ship (to be counted in the fore-aft direction.)
- Rows: Identify the position of the cell relative to the vertical section of the corresponding bay (to be counted from the center of the ship to the sides.)
- Tiers: Identify the position of the cell relative to the horizontal section of the corresponding bay (to be counted from the bottom of the vessel to the top.)
Each container is then stowed in a cell, located in a bay, positioned on a certain row and at a certain level.
All information relating to the structure of a ship is entered in the “ship profile” sent by shipping companies to the stopover terminals of each ship’s route. This document contains all the information related to operational and structural constraints of the ship, the number of bays, rows and tiers of which it is composed, and the set of Bay Plans that allows one to know, for each bay, the number and position of the cells available for stowage.