The 12,968gt E-Ship 1 was built in 2010 by Lindenau at Kiel and completed by Cassens Werft in Emden. She is seen here at Londonderry in May 2016. (Nigel Lawrence)

Transportation is still heavily reliant on fossil fuels, so it’s not surprising that shipping companies are always looking for ways to reduce operating costs. Improved fuel efficiency has the added advantage of reducing carbon dioxide (CO2) emissions in this era of concern about climate change. Regardless of any voluntary improvements it’s made, the shipping industry faces a new regulatory burden in 2023 as the European Union introduced an emissions tax.

For centuries wind provided free, albeit inconsistent, power for sailing ships. Alone, it’s not nearly strong enough to move modern cargo vessels at a suitable speed, but a novel method of auxiliary propulsion harnessing the wind can be seen on some cargo ships and ferries. This makes use of a force discovered over a century ago.


Experimental scientist Heinrich Magnus researched a force on spinning spheres and cylinders in the 1850s. Known as the Magnus Force, it can be observed when a ball is kicked or hit such that it spins, curving its trajectory. In the next century, aviation engineer Anton Flettner tried to apply this effect to aeroplanes and realised it could be utilised on ships when wind speed and direction is favourable. Flettner’s insight is that when air flows around the cylinder it’s deflected in the direction of spin on one side, while on the other it’s slowed against the spin. Consequently, the air exerts a force on the cylinder towards the faster, lower pressure, air.

The 455grt Buckau was built in 1920 by Krupp Germania at Kiel for Friedrich Krupp AG. In 1924, when owned by Hanseatische Motorschiffahrt AG, she was fitted with rotor sails. In 1926 she was renamed Baden-Baden and in 1929 after having her rotors removed, she was sold to Hans Lau of Costa Rica as Rio Nozara. On 8th November 1931 she sank off Cartagena, Colombia while on a voyage from Manuare to Cristobal with a cargo of salt. (Library of Congress)

Sign-up today to read the full article!

Simply click below to sign-up and read the full article, as well as many others, instantly!


Sign-up nowLog In


Sorry, comments are closed for this item