Several designs have been proposed for adding sails, of one shape or another, to ships in addition to an active mode of propulsion in order to reduce fuel consu

Several designs have been proposed for adding sails, of one shape or another, to ships in addition to an active mode of propulsion in order to reduce fuel consumption. Further, the ships take a significant amount of energy to get going, so much of that initial acceleration could be handled by strong tug boats which would then be immediately recharged.