The concept behind containerisation is the packing of cargo into uniformly sized boxes (containers) and then designing all carrying vehicles (road, rail and ship)for the swift and efficient transport of these “boxes”, ideally from “door to door”. In order to make this feasible, it was necessary that an internationally accepted standard be adopted with respect to the size of containers, since all cell guides in a ship into which the containers are loaded, the gantry cranes and equipment and the road and rail transporters need to conform to these standards.

Design features.

• The container ship is larger than the general cargo ship.
• In most cases they do not have their own cargo handling facilities.
• Special terminals have to be built and fitted with huge gantry cranes for loading/off loading the ships as well as special vehicles for lifting, moving and stacking the containers. The terminals also require deep water berths to accommodate the container ships.
• Container ships are faster than general cargo vessels and can achieve speeds in excess of 22 knots.
• Since the containers have to be lowered into cell guides, sophisticated and high speed ballast arrangements are necessary to ensure the ship remains upright and level at all stages of loading.
• Containers are loaded on deck as well as in the holds, with twist locks inserted into lifting holes to ensure that they are locked together.

Safmarine container ship.

Advantages of containers.

1. Loading and discharging is much faster in ports, so time alongside is shorter.
2. Since there is less handling of cargo, there is less breakages and pilfering.
3. Packaging is reduced.
4. The cargo is protected from the weather.
5. The service offered is virtually “door to door”.

Disadvantages of containers.

1. A massive capital outlay is required for the ship which is more expensive than a conventional carrier.
2. Each ship requires three sets of containers, one at each port (departure and destination) and one onboard.
3. Special handling terminals have to be built with expensive high speed cranes capable of lifting in excess of 40 tons. Expensive machinery is also required for moving the containers around the terminal.
4. Containers can be used by criminals to move contraband goods and drugs.
5. Depending on the import/export characteristics of a country, an imbalance of trade will result in containers being brought home empty.