Reduction in ship fuel consumption and emission by sailing at slow speeds

The fuel cost of a ship is the largest component in total ship operating costs, amount to 50-60% of the total operating costs. Several methods considering both technical and operational aspects have been investigated to reduce the fuel costs. Reducing the ship speed, better known as “slow steaming,” is currently used, because it is considered more effective than other method to reduce fuel consumption and emissions `of ship. This paper reports on a study conducted to determine the effect of ship speed on the level of fuel consumption and emissions. The object of this research is a container ships that sailing from Surabaya (SUB) to Belawan (BLW), Indonesia. The fuel consumption and emissions were numerically calculated. Ship emissions calculated using the emission calculation method developed by Puget Sound Maritime Air Emission Inventory (PSMAEI) published in 2016. The calculation results show that there were savings in fuel consumption of almost 40% with the total ship sailing time from SUB to BLW is still within safe limits of time windows. The results of the calculation of emissions also indicate a decrease in the amount of emissions. It can be conclude that it is possible for a ship to sail at less than the service speed. This approach can save fuel consumption and reduce emission levels compared to those when ships sail at the service speed.