The maiden voyage of the 18,000 teu vessel Maersk Mc-Kinney Moller has been accompanied by much fanfare about record container handling productivity at various ports. Whilst it is generally true that larger vessels can facilitate faster port handling, the correlation between ship size and speed of port handling is not necessarily linear.
The move by all major carriers towards ever larger vessels in the pursuit of economies of scale is not automatically matched by similar advantages in terms of the speed of port handling. For shipping lines, what matters is turnaround time from vessel arrival to vessel departure – and essentially this means berth moves per hour across the ship. A key factor is gantry crane intensity across the ship, i.e. the maximum and average number of cranes deployed during the port call.