Geared container ships, which are container ships equipped with their own cranes for loading and unloading containers, are less common compared to non-geared container ships for several reasons:
Efficiency: Non-geared container ships are often more efficient in terms of speed and fuel consumption. Geared container ships typically have lower speed and higher fuel consumption due to the additional weight and space taken up by the cranes.
Port Infrastructure: Most major ports around the world are equipped with shore-based container cranes that are used to load and unload containers from ships. This reduces the need for ships to have their own cranes. Ports are typically more efficient at handling containers than ships, so it makes more sense to invest in port infrastructure rather than equipping ships with cranes.
Flexibility: Geared container ships are less flexible in terms of the types of cargo they can carry. Ships with cranes are typically designed to handle specific types of cargo, whereas non-geared container ships can carry a wider variety of containerized cargo.
Cost: Equipping a container ship with cranes is expensive both in terms of initial investment and ongoing maintenance costs. For many shipping companies, it is more cost-effective to use non-geared container ships and rely on port infrastructure for loading and unloading operations.
Specialization: Some shipping companies may choose to operate geared container ships in niche markets where the use of cranes on board the ship provides a competitive advantage. However, for most shipping routes and cargo types, non-geared container ships are more commonly used.
Overall, while geared container ships have their advantages in specific situations, the majority of container shipping is efficiently handled by non-geared container ships that rely on port infrastructure for container handling operations.
Simple: containers are stacked in slot guides under deck and in accurately positioned stacks on hatch covers. In order to position them precisely, with the tolerance of less than an inch at each corner, you need a gantry crane. A pivoting crane with a single point suspending a container spreader is much too unstable for stacking containers at a fast rate.
A good gantry crane rate is 50 moves per hour, while you'd be lucky to move a tenth of that by swivelling shipboard cranes. A few early container vessels were fitted with travelling gantry cranes on deck, but that came at the expense of cargo capacity. These days, shore container cranes are common in most ports, hence only small container vessels still have cargo handling gear.
At one time, long ago, many ports did not have cargo handling facilities for transferring goods from ship to dock. Today, ports, with rare exceptions, are more efficient at cargo handling than ships with their swiveling cranes ever were, plus containers have revolutionized how cargo is dealt with in all areas. Small ships in out of the way small harbors still do things the old way, but they are inefficient and dreadfully slow in turnaround.
