Crane double cycling in container ports: Planning methods and evaluation

In this paper we look at the longer term impact of double cycling on port operations including crane, vessel, and berth productivity. Double cycling is a technique by which empty crane moves are converted into productive ones. We use a double cycling sequence that is operationally convenient, easy to model, and nearly optimum. We evaluate the performance of this sequence over single cycling. A framework is developed for analysis, and a simple formula is developed to predict the impact on turn-around time. The formula is an accurate predictor of performance. We show that double cycling can, in some cases, reduce the requirements for yard tractors and drivers. The paper also comments on strategies for altering port operations to support double cycling such as segmenting vessel storage, and streamlining traffic flows. We show that double cycling can reduce operating time by 10%, improving vessel, crane and berth productivity. We identify additional benefits on the landside, but these are typically much less significant.