THELASTMILE Logistics Outside the Box
Cargo Ships Get Wind of Traditional Power Source A millennia-old concept—wind propulsion for cargo ships—is catching on with some gusty tech innovations.
Giant Cylinders Pressurize and Eject Air A University of Miami College of Engineering professor is developing giant cylinder sails that could power cargo ships using co-flow jet technology from his ongoing work with new aircraft.
Setting Sail with Wind Only about 30 cargo ships—out of the global fleet of approximately 60,000 cargo ships—utilize wind propulsion technology. The few cargo ships using wind propulsion have rigid sails made of aluminum, fiberglass, and carbon fiber that run on minimum power from a ship’s engines. That number is expected to increase to nearly 11,000 by the end of this decade, according to the International Windship Association.
GeCheng Zha, a professor of aerospace engineering and director of the Aerodynamics and Computational Fluid Dynamics Lab at the university is working on cylinders that could be mounted on the decks of cargo ships; each cylinder could be lowered so ships could traverse beneath bridges and in and out of ports. The non-rotating cylinders use no moving parts; they would generate thrust by sucking in air, pressurizing it, and then ejecting it in a different direction.
Wind-Powered Ocean Vessel Makes Maiden Journey The Pyxis Ocean , a cargo ship fitted with giant, rigid sails, set out on its maiden voyage in August 2023 and recently announced results from a six-month test period. The MC Shipping vessel retrofitted with two WindWings—large solid wind sails developed by BAR Technologies—achieved an average of 3.3 tons of fuel reductions per day. Resembling large airplane wings, the two WindWings
are installed vertically to catch the wind and propel the ship forward, allowing the ship’s engine to be turned down so that the ship can travel at the same speed as a conventional ship using less fuel. Shipping firm Cargill chartered the vessel, working with BAR Technologies and MC Shipping.
Wing Sail Set to Take Flight Oceanbird—a joint venture between Alfa Laval and Wallenius—is installing its first wing sail on car carrier Wallenius Tirranna ; the wing sail foundation was recently completed on its deck. The Wingsail 560 is named after its size: 560 square meters or more than 6,000 square feet.
Consisting of a main sail and a flap to optimize aerodynamic forces by creating camber, one wing sail on an existing RoRo vessel at normal speed can reduce fuel consumption from the main engine by 7-10 % on favorable oceangoing routes, Oceanbird estimates. The Wingsail 560 can be installed on existing and newbuilt vessels, as the main propulsion or engine support.
Sources: Interesting Engineering; BBC News; Popular Science; Cargill
56 Inbound Logistics • August 2024
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