Some interesting responses and pictures in this Quora question: https://www.quora.com/Why-don%E2%80%99t-modern-civilian-cargo-ships-also-use-sails-in-addition-t

Some interesting responses and pictures in this Quora question: https://www.quora.com/Why-don%E2%80%99t-modern-civilian-cargo-ships-also-use-sails-in-addition-to-engine-power-to-reduce-fuel-consumption https://www.quora.com/Why-don%E2%80%99t-modern-civilian-carg...