Slow Steaming

Slow steaming is the deliberate reduction of service speed below design speed to cut fuel consumption and emissions, exploiting the roughly cubic relationship between speed and propulsion power. A 10 percent speed cut lowers power demand by about 27 percent for a given hull. It became widespread after the 2008 fuel-price spike and remains a primary lever for CII compliance under MARPOL Annex VI and for cost control in weak freight markets. Sustained operation well below design load needs attention to engine de-rating, turbocharger matching, and cylinder lubrication.