Container moves per lift: the impact of spreader technology on bay time

Abstract

The trend of increasing containership size (length, beam, and draft) continues. The increase in containership size, especially beam size (bay size), increased berth and port time at a given number of lifts per hour. There are emerging technologies that allow a spreader of ship-to-shore gantry to handle multiple containers in a single lift.  This paper studies the impact of the increase in the containership bay size on berth time and the role the spreader of gantry cranes can play in keeping up with the increase of bay size, thus reducing vessel port time. The paper analyzes the moves of containers per lift with different spreader technologies, where a spreader can handle one or multiple containers in one lift. The paper determines the combination of spreader technology needed to accommodate mega containerships with large bay sizes in order to reduce vessel port time. After a literature review, using the bay time determination method developed by the authors, the paper analyzes the moves per lift of different spreader technologies, vessel operations and containership bay size configurations. The analysis determines the optimal combination of equipment to comply with liner service schedules and the difficulties the equipment might pose on a marine container terminal.