A ship weather routing system towards enhancing energy efficiency is briefly introduced firstly. This system is composed of several modules, including ship performance calculation, grids system design, weather routing, ship safety etc. However, when the system was first developed, due to the complicated relationship among these modules and their very huge calculation amount, the working efficiency is very low. Therefore, several methods to improving the working efficiency of this system are designed. Finally, a Bulk Carrier voyage is taken as a case study to prove the validity of these methods. The results show that, with all of these methods, the working efficiency of this ship weather routing system can increase almost 97%.
Ship weather routing is used to determine optimum route (course and speed) between given departure and destination ports based on weather conditions and ship's corresponding performance. It always aims to minimum fuel consumption, suitable ETA (estimated time arrival) or maximum ship safety etc. It has been proved as a very effective tool in shipping field (Simonsen, 2015; Chen, 1998; Buhaug, 2009). People have made great progress on this topic with many weather routing methods developed. The very common methods are: Calculus of variations (Bijlsma, 1975), Isochrone method (James, 1957), Isopone method (Klompstra, 1992, Spaans, 1995), Dijkstra's method (Padhy, 2008; Panigrahi, 2008, Eskild, 2014), Dynamic programming method (De, 1990, Calvert, 1991), 3-dimensional dynamic programming method (Shao, 2013), DIRECT (Dividing RECTangles) method (Finkel, 2003; Larsson, 2015) and some evolutionary algorithms (Hinnenthal, 2010, and J.Szłapczy'nska, 2007) etc. Besides, experts have developed some famous commercial ship weather routing software like OpenCPN, qtVlm, VOSS, VVOS etc. and applied them in the shipping market. All of above make great contribution for the benefits of shipping market.
In this paper, a ship weather routing system for energy efficient shipping is briefly introduced. This system is composed of several modules, including grids system design module, weather routing module, ship safety module, etc. Every module has its own task, and every of them should cooperate with each other so that the whole system can run well towards to a shipping mission. However, the working efficiency of this relatively complicated system is not high enough. For one simple case, it always takes a great of hours to complete calculation, which can not meet the practical demands. Therefore, several methods to improving the working efficiency of this system are designed. These methods include not only system running logistic changing, but also shipping algorithm optimization and programming codes optimization.