Analysis of Fuel Efficiency Optimisation Strategies for Cargo Vessels Operating Between Nigerian Ports

Fuel consumption constitutes the largest operating cost for commercial cargo vessels and simultaneously represents the primary source of maritime greenhouse gas emissions. This study analyses the effectiveness of fuel efficiency optimisation strategies applicable to cargo vessels operating on Nigerian coastal trade routes between Lagos, Port Harcourt, Warri, and Calabar. Employing an empirical operational data analysis methodology, the research draws on voyage data recorder and noon report data from fifteen cargo vessels over a twenty-four-month operational period. Three principal optimisation strategies are evaluated: voyage speed optimisation through slow steaming, trim optimisation based on loading condition, and main engine performance monitoring with targeted maintenance intervention. A regression model is developed to quantify the independent contribution of each strategy to fuel savings, controlling for vessel characteristics, cargo weight, sea state, and route. Results indicate that speed optimisation through a fifteen percent reduction from maximum service speed produces the largest single fuel saving of between twenty and twenty-five percent, while combined trim and speed optimisation yields cumulative savings approaching thirty percent compared to baseline consumption. The study contributes quantified evidence of optimisation strategy effectiveness specific to Nigerian coastal route conditions, where variable current patterns and port congestion significantly influence voyage efficiency. Recommendations include adoption of voyage management software by coastal shipping companies and integration of fuel performance metrics into commercial charter agreements. Keywords: fuel efficiency, cargo vessels, speed optimisation, trim optimisation, coastal shipping