Quote Originally Posted by FEM2008 View Post
I could not remember the vertical rotary sail are called (Flettner Rotor Sail), but I ran across this site while looking.
After almost a century, these Flettner rotors are getting a 2nd chance right now on M/S Viking Grace for the Stockholm-Helsinki cruise line:
https://www.vikingline.com/the-group...ce/rotor-sail/

I seem to remember that this was even mentioned here before: Magnus effect rotary sail propels cruise ship - GIF