Prediction of Travelling Time and Exhaust Gas Emission of Ships on the Northern Sea Route

Abstract

In order to simulate the impact of increased shipping activities to the arctic environment for a scenario with decreasing ice extent and ice volume, a simulation tool for ship travelling time was enhanced with regard to the determination of fuel consumption and exhaust emission on the Northern Sea Route (NSR). The tool was then used to investigate the impact of ships in different periods within the years 2000 and 2007 with various ice conditions. The transit speed is compared for different periods in the past and present by using ice records from different years together with route parameters and ship data as input for a simulation program. The program is able to calculate the ship resistance in open water and additional components due to wind, waves and ice within a speed range. By including specific propulsion data of the ship, a requested power is obtained for the speed range. The maximum speed is finally interpolated using the maximum available shaft power. The simulations are carried out for three different ship types with different hull shapes and propulsive power. The results show a significant decrease of travelling time for 2007 compared to 2000. Further in 2007 the season in which transport via the NSR is profitable is clearly extended to the winter months. In a second work task the program is further developed with respect to the determination of fuel oil consumption and exhaust gas emission. Due to increased resistance during ice breaking, high thrust has to be provided at low speed leading to an off design condition for propulsion arrangements which are optimised for service speed in open water. It can be found that the resulting actual fuel consumption is closely related to the operation profile of the ship. High values for fuel consumption thereby occur at service speed in ice free water but also at very low speeds in very tough ice conditions. For moderate ice conditions the fuel consumption and related emissions can be lower especially if the ship is forced to slow steaming for safety reasons.