Why Don’T Modern Ships Have Sails?

The International Windship Association reports that over 20 commercial cargo ships already use wind-assist technologies retrofitted on existing vessels. A sailing ship differs from a powered craft in structural terms, as it requires a strong, weighted keel and the ability to support masts, rigging, and sails. Wallenius Marine is developing the Oceanbird, able to ship 7,000 cars and trucks across the Atlantic propelled only by high-tech wing sails. Many ports, adapted for modern container ships, stopped accepting older ships and would have to make changes to accommodate them. If left unchecked, shipping could account for almost a fifth of global emissions by 2050.

Modern wind propulsion technologies might help the industry decarbonize. A diesel ship that’s retrofitted with wing sails will pollute much less than its peers but still won’t be clean. Researchers are revisiting an ancient maritime mainstay with a modern twist: sails. However, wind-powered cargo ships ruled the world’s waves back in the 19th Century, and the adoption of the steam engine saw them replaced by much-larger, coal-powered alternatives. Cargo vessels emit almost as much carbon into the air each year as the entire continent of South America.

Adding sails would cost money and provide unpredictable power, but modern shipping is all about doing things cheap and predictably. Long waterlines, straight line transits, held plans, and cheap fuel trumps the savings by adding the complexity of sails and rigging. Modern cargo ships do use wind power to assist fuel reduction in transit, such as launching a huge kite for sail handling.

In conclusion, modern sails could have a surprising impact on shipping, but they require technological advancements and careful planning to achieve zero carbon emissions.