They are literally kites—not sails. I’ve never seen a sail flying 100 ft above a ship before.
https://en.m.wikipedia.org/wiki/Parasailing
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parasail
https://en.wikipedia.org/wiki/Spinnaker
When a vessel is running (meaning moving in the same direction as the wind) it can fly a spinnaker, which is just a kite on short lines.
And the load on its sheets is enormous. Oh boy can it cause a problem if anyone makes a mistake handling it! Now imagine the load from the kites proposed. I wonder if that is even feasible with today’s materials.
Edit: did some reading around. So it seems at current level the system can be used as a supplementary propulsion saving some fuel. Ahoy, mates, we are back and our sails are higher than ever!
When it comes to material stresses the sails can always be scaled down, but off the top of my head kevlar and zylon would be good candidates for getting the biggest, toughest sail in an economic fashion.
If you want to go down a related rabbit hole take a look at the sails used in regattas. The technology and money that goes into them is ridiculous.
Why the fook is the flag flying against the wind?!?
Sails don’t billow into the wind. They are set at an angle to it. Just enough to inflate them, creating an airfoil. The remaining wind blows across the airfoil, creating “lift” (like vertical airplane wings) that pulls the boat along more efficiently. That’s why sail boats can actually go faster than the wind.
From this photo, the wind is blowing almost parallel with the sails.
The type of sail you’re referring to is ‘bermuda-rigged’, like the smaller ones at the front of the boat in the picture. The big ones in the middle of the picture are ‘square-rigged’ which are really only good for sailing downwind.
I think the square rigged sails could be rotated, so you could sail with a cross wind. You would just have a fair amount of trouble sailing upwind.
Big kites if true
And what is wrong with taking stress off the engines? I hate how they report this like it is a joke, because it is still a solid step.
They’re not a joke, they’re a product called Seawing, made by a French company. They’re being being actively tested and can be retro fitted to existing vessels rather than requiring a new design.
Correct, I think they were saying it was being reported on as if it was a joke. Not being taken seriously as a good step towards reducing carbon emissions.
And they’re a lot more advanced than traditional sails.
Traditional sails only work with surface winds, which are relatively weak. These giant kites can go much higher and take advantage of much stronger and more reliable winds at higher altitudes.
I’m not sure who they wrote that headline for. “Giant kites” is one thing, but what really stood out to me was that they added on the “reduces carbon emissions” as if that part would be unexpected. Like the whole point of these giant kites is to pull the ships and reducing carbon emissions is icing on the cake, rather than sails coming back because they are a carbon-neutral method of propulsion.
I know this isn’t really anything new, but it dies look like they are making progress while is great.
They will have planning for that, just like they do the container ship towers which also have to deal with lightening.