Economies of Scale
Ship overall efficiency is a function of ship size. The larger the ship, it will have a lower fuel consumption per unit cargo transported and lower CO2 generated. Operationally, energy efficiency and emission reduction can be increased by concentrating the transportation of cargo on larger ships that can reduce the energy consumption of the shipping industry as a whole. However, few practical considerations should be taken into account. These large ships will be limited to a few deep-water hub ports; this means that the cargo will still need to be trans-shipped to its final destination. This can result in the overall door-to-door logistical performance of the movement of the cargo being reduced unless smaller ships that can take the cargo to smaller ports to support these large vessels could perform their part efficiently. These smaller feeder ships will be less efficient anyway than the large ships and there will also be some extra GHG emissions penalties in the additional discharging and loading operation for trans-shipment (MariEMS 2017).