<center>
![](https://steemitimages.com/DQmUv1vn4W8cZwc3sczboXLJx881QWGcg7TNqB3txJbBhyR/image.png)
</center>
# <center> [Spinning metal sails could slash fuel consumption, emissions on cargo ships]( http://www.sciencemag.org/news/2017/09/spinning-metal-sails-could-slash-fuel-consumption-emissions-cargo-ships) </center>
<center>
.......................................................................................................................................................................................
</center>
<center>
 ![](https://steemitimages.com/DQmT43U1UHcD8i6EgnPNkQu95nzMGRVxRBdPRjqJMfZKqDQ/image.png)
</center>
* Early next year, a tanker vessel owned by Maersk, the Danish transportation conglomerate, and a passenger ship owned by Viking Line will be outfitted with spinning cylinders on their decks. Mounted vertically and up to 10 stories tall, these “rotor sails” could slash fuel consumption up to 10%, saving transportation companies hundreds of thousands of dollars and cutting soot-causing carbon emissions by thousands of tons per trip.
.
Rotor sails rely on a bit of aerodynamics known as the Magnus effect. In the 1850s, German physicist Heinrich Gustav Magnus noticed that when moving through air a spinning object such as a ball experiences a sideways force. The force comes about as follows. If the ball were not spinning, air would stream straight past it, creating a swirling wake that would stretch out directly behind the ball like the tail of a comet. The turning surface of a spinning ball, however, drags some air with it. The rotation deflects the wake so that it comes off the ball at an angle, closer to the side of the ball that’s rotating into the oncoming air. Thanks to Isaac Newton’s third law that every action must have an equal and opposite reaction, the deflected wake pushes the ball in the opposite direction, toward the side of the ball that’s turning away from the oncoming air. Thus, the spinning ball gets a sideways shove.
***
<center> it's been done...not a new thing.
 ![](https://steemitimages.com/DQmS2re8S7HdHPjqoUQVBU8xREqLCqLo8H5Zr4FhKscUMyb/image.png)
[credit]( https://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Buckau_Flettner_Rotor_Ship_LOC_37764u.jpg/1200px-Buckau_Flettner_Rotor_Ship_LOC_37764u.jpg)
***
  http://sdtb.de/fileadmin/user_upload/_tem/02_Ausstellungen/02_Sonderausstellungen/2010_02_Flettner-Rotor/415_268_BARBARA_frontal.jpg
[ credit](http://sdtb.de/museum-of-technology/exhibitions/1623/)
***
 ![](https://steemitimages.com/DQmehgy7ECuGtQrj6VR73JgBAGHg6SvTJkctVdZnjZw1aRf/image.png)
[credit](  http://www.bestofjay.com/w/rotor-boats-are-making-a-rebound-no-sail-needed/)
***
Which causes me furiously to think
Inflatable plastic cylinders are cheap. They are sold as _watertoys_ because the float.
 ![](https://steemitimages.com/DQmUQKCuYpMcBJi8xsQDSHmkAvHVuDvsTYdzxXHEvyTVcAj/image.png)
all sizes and prices.
 ![](https://steemitimages.com/DQmekzBNKd1WWm6EBaPFQBwLABrTAwK6jGoT8wMPW6TTSJo/image.png)
some are pretty tough.
 ![](https://steemitimages.com/DQmUSw9mseqxQwm4RoqBTPGgGzs7cGZKH65Jg7CUUvsoZ8r/image.png)
ya think?
 ![](https://steemitimages.com/DQmPNtzYUGebWi7ZUfPhvWvPvpN16JbSitbfQ4myB9cdzV6/image.png)
fill em with something lighter than air....in this case just HOT air.
***
Lord help me.
I'm having an idea.
***
Imagine an inflated lighter than air, flettner cylinder ....sail?
Imagine the possibilities.
It'd not _heel_ so much...
it'd definitely float..(in the water)
to control the 'tack' into the wind...just reverse the spin.
***
hmmmmmmm?
</center>