A New Routing Optimization Tool-influence of Wind and Waves on Fuel Consumption of Ships with and without Wind Assisted Ship Propulsion Systems

Within the research project ROBUST** (Optimization of seaborne trade) a new software tool was developed to find the optimum shipping route, considering the influence of wind and waves on the ship's performance. A further aspect thereby is to assess the potential of wind assisted ship propulsion systems (WASP) in addition to the conventional diesel propulsion.The influence of wind and waves on the ship's performance in general is estimated by experience and model tests before ship construction. For the actual influence on a seagoing cargo ship, there is not much information available. For the research project ROBUST a 17.500 DWT multipurpose cargo ship was equipped with measuring systems (providing all 10 min 64 data) to get continuous information about the influence of wind and waves on the ship performance (Wave data, power on shaft, machine consumption,…). For more than one year, data were collected worldwide. These data were used to fit computer models to calculate the influence of wind and waves on the ship performance.Based on these models, a branch and bound optimization system was developed to find the most efficient route for a given weather situation. The optimization is aiming for an energy minimum of the route. As a restriction the modification of the route is limited by a given time window for the traveling time. This effect of a WASP is discussed for a Flettner rotor. Results for a kite system and a Dynarig are calculated as well, but are not presented here. The route optimization system is tested with historical weather data from the German DWD. The simulations show that relative small adoptions of the route to the actual weather situation may give an interesting potential for savings of energy and thereby of costs.