Really? I mean over the life of the ship in all winds, on all relative bearings, in all conditions. I don’t believe you. You’ll need something a bit more solid than “Yes”.
So you pay the extra cost of the sailing gear on top of the normal capital cost and maintenance of a normal ship. Again I’d need to see the cost benefit over the lifetime.
Don’t need no stinkin’ icebreakers!
Try it on any sail boat. Motor vs motor-sail, you’ll see fuel savings with motor sailing. There’s no question about it.
I can’t say whether it’s cost effective currently.
It wouldn’t be rope rigging and cloth sails.
I note, “she motored for most of the voyage” and needed to fuel on the way.
But my congratulations to the ship’s captain.
P.S. I think it’s spelled “steenkin’ “
He probably wouldn’t be invited on board for a visit even.
Here is a real square rigger. I did my pre-sea training on this one and sailed with her as crew on the last trip BEFORE she got an engine installed (1959)
Have you ever heard about the Magnus effect?:
https://www.norsepower.com/technology/
Here is another “sail powered” RoRo that doesn’t look like an 1850s square rigger:
PS> I don’t know how this “sail” work, but it is probably explained somewhere. (??)
Yes. So what is the answer to the question I asked repeated below?
Show me the evidence. I don’t want fancy gadgets. I know every version of sail power there is. I want costs versus benefits over a ship’s lifetime.
In that case you can probably tell us about how that last car carrier project work?
Not EVERYTHING is a question of $$$ savings, but there are any numbers of studies showing savings, both in reduced GHG emission and $$
The people that is involved in the development of new sail technology and future marine fuels are not idiots, liars or “snake oil sellers” but serious Engineers or Scientist.
The ones that put their money into the development of such projects are out to make money though.
One mariner’s endless head winds is another mariner’s favorable trade winds.
Only for the politically incorrect.
Benefits to whom?
This thread has started to read like endless headwinds 
The problem is even if it reduces fuel consumption for it to be economically viable the cost over the life of the system has to add up.
That’s why it needs to be automated. A couple extra crew members to deploy and retrieve it kills the fuel savings.
They’re are modern sail systems that don’t need to be “deployed and retrieved” at all.
There are, but I don’t think they will ever be cost effective over the life of the vessel. They could be a possibility on certain limited routes and cargo types.
They seem most likely to be used on tankers because they don’t carry deck cargo. The Japanese tried that in 1980 but fuel prices didn’t stay high long enough.
I think that technology is more or less mature.
Kite technology is still in its infancy. The theoretical possibilities are very impressive but it still needs to be demonstrated in practice.
Everybody, there’s your answer. Costs outweighed benefits.
Lots of generalities quoted at me about how wonderful wind power is, but it is inevitably more expensive.
The question has been asked here by me and others, how often has your relative wind been from ahead of the beam and the answer is almost always. Unless you are prepared to plan your passage as sailing ships did (ie longer, slower voyages) the opportunity to make effective use of wind is limited to a minor proportion of each voyage.
But waste your money if you want. Go woke, go broke.
Eventually, the one with favourable winds runs into land … and wants to come back.
To the one who pays - the customer.
there have always been clever people that want to push technical boundaries and they quite often get prototypes or one offs built but very little ends up in production.
Often something trialed today is not financially viable but might be in future years or forced if the rules change.
Shipping seems to be very slow in doing anything but making great news headlines.
