Maersk is testing a giant spinning cylinder to cut fuel use on cargo ships

On a cargo ship packed with 8,700 shipping containers, there isn’t much room for anything else. But in a new test aboard one of its vessels, Maersk is making an exception for a giant rotor sail—a spinning cylinder 10 to 12 stories tall that harnesses wind to help reduce fuel use. The test comes as shipping fuel costs continue to soar. In some areas, the price has risen as much as 76% since the Iran war started. The tech, made by a U.K.-based company called Anemoi, is one way to help blunt fut...