On the Speed of Ships

Ship speed is a parameter that influences the energy efficiency of a ship. For this reason it has been considered as a parameter that could be used to reduce the carbon emissions of the existing and future global fleet of ships. Operational speed is an economic function of market conditions (freight rate) and the costs of operation (e.g., bunker fuel costs, cost of additional ships to meet the equivalent output) because along with the ship size, speed determines the industry’s supply. Therefore speed can also be a cost-effective increase in energy efficiency for the ship owner and operator, although the level to which this is attractive will vary over time according to the agent’s tradeoffs between revenue and cost. This paper reviews existing literature in order to highlight some of the common assumptions and ideas in the pertinent subject areas: energy efficiency, engineering, economics, environmental impact. Models are developed and their initial results presented, in order to interrogate the sensitivities of some of these assumptions. There is also discussion of the subject of speed in the evolving policy and regulatory discussion at IMO.