Port Planning for Double-Cycling Crane Operations

In this paper we look at the longer term impact of double cycling on port operations including crane productivity, and requirements for landside vehicles, drivers, and chassis. We use a double cycling sequence that is operationally convenient, easy to model, and turns out to be nearly optimum. The sequence in which container stacks are handled does not depend on the loading pattern for each vessel; it is determined by physical location alone. A framework is developed for analysis, and a simple formula is developed to predict the impact of double cycling on vessel turn-around time. We compare results using this formula to those using a simulation program, and find the formula to be an excellent predictor of performance. We show that double cycling can reduce vessel operating time by 10%, improving vessel productivity, crane productivity and berth productivity. It can reduce by about 20% the requirements for yard tractors and drivers. Further, for wheeled operations, we suggest a method to reduce the requirement for chassis by about 25%. We estimate the financial impact of these benefits, which total approximately $20.00 per container moved.