Institute of Transportation Studies at UC Berkeley

Double cycling improves efficiency by unloading and loading a ship simultaneously; using wasted crane moves to transport containers. This paper demonstrates that double cycling can reduce ship turn-around time through this efficiency improvement. The paper describes the nature of the double cycling problem and, for a given loading-plan, quantifies the benefits using a greedy algorithm. The relationship between the benefits of double cycling, and the problem parameters is analyzed using simple formulas and a simulation program. This paper demonstrates that double cycling can create significant efficiency gains, and should benefit any party interested in improving port operations, and reducing the cost of container shipping.