Rotor sail helps Finnish ferry Viking Grace reduce fuel consumption(metropolitan.fi)
metropolitan.fi
Rotor sail helps Finnish ferry Viking Grace reduce fuel consumption
https://metropolitan.fi/entry/rotor-sail-helps-finnish-ferry-viking-grace-reduce-fuel-consumption
68 comments
Simple reasons:
1. A ferry can be inspected continuously - after every run, end of day, end of season, etc.
2. The sail can be in the ideal position.
3. The sail will not get damaged during the loading/unloading process.
1. A ferry can be inspected continuously - after every run, end of day, end of season, etc.
2. The sail can be in the ideal position.
3. The sail will not get damaged during the loading/unloading process.
Many cargo ships are open topped to speed up loading an unloading. Others have lids, but then put stuff above those lids again making large structures above deck difficult.
Back in about 2009 my brother's urban design firm in London handled a European Union funded rethink of IIRC Falmouth, which is a port in Cornwall. He explained that under EU regulations that was the last port that trans-atlantic ships were allowed to dock at to pump out bunker fuel and replace with EU-acceptable fuels for the transit further east along the channel.
This has already been done for cargo craft.
https://en.wikipedia.org/wiki/E-Ship_1
https://en.wikipedia.org/wiki/E-Ship_1
> "Cargo shipping is ruthlessly cost-competitive, and fuel is currently 50-60% of costs. [1] With the new regulations that percent will increase"
- Yes. Ultimately increasing the cost of the goods shipped.
-(Relatively) inexpensive shipping / transport is the foundation of the global economy. It's also its Achilles' heel.
Even if currently a financial break even, these sails seem like a smart hedge going forward. The eco benefit being the bonus round.
- Yes. Ultimately increasing the cost of the goods shipped.
-(Relatively) inexpensive shipping / transport is the foundation of the global economy. It's also its Achilles' heel.
Even if currently a financial break even, these sails seem like a smart hedge going forward. The eco benefit being the bonus round.
Would it stop absurd transportation of goods like exotic fruits all year long ?
If people stopped buying things from far away that aren't really really necessary, maybe that will also reduce fuel use.
If people stopped buying things from far away that aren't really really necessary, maybe that will also reduce fuel use.
Buying things from far away is the point of living in a modern, global economy. You don't get people on your side by telling them they want the wrong things. The way forward is to give people what they want in a sustainable way.
If someone's feet hurt, you don't tell them to lie down for the rest of their lives. You tell them to get better shoes.
Global trade reduces global warfare, too.
If someone's feet hurt, you don't tell them to lie down for the rest of their lives. You tell them to get better shoes.
Global trade reduces global warfare, too.
I'm happy about warfare channeling through economic relations but the rest is bullshit IMO. I believe more in locality rather than having constant supply of things from all over the world. And that it's "THE" point of a modern economy couldn't be more pointless to me.
I'm genuinely curious about what is the right size of "local"
same timezone, same latitude band ?
That means a car economy, the question of what is local is a good one, there is a reason the world population is spread out the way it is.
- grow more vegetables and fruits nearby (lots of unused space)
eat them
- gather local material as much as possible
use them with creativity (see the wood based buildings for instance)
I don't accept the "world status" anymore
eat them
- gather local material as much as possible
use them with creativity (see the wood based buildings for instance)
I don't accept the "world status" anymore
Or at least price the unsustainable goods to reflect the harm they're doing to the environment, and use that extra money to help fix it.
Global shipping is very efficient per tonne.
The fuel used to ship your fruit from another side of the world is less or equal to the amount of fuel used to move the fruit from the harbor to your home.
If locally produced fruit requires refrigeration, they are very likely less ecological than shipping dried fruits or canned fruits from another side of the world.
The fuel used to ship your fruit from another side of the world is less or equal to the amount of fuel used to move the fruit from the harbor to your home.
If locally produced fruit requires refrigeration, they are very likely less ecological than shipping dried fruits or canned fruits from another side of the world.
You really, really, really don't want that to happen. Globalisation and global economies are very good things for human and technological development.
If you scale back economies of scale you lose their efficiencies and it becomes a positive feedback loop where shipping rates increase and cost of goods increase and volumes decrease.
If you scale back economies of scale you lose their efficiencies and it becomes a positive feedback loop where shipping rates increase and cost of goods increase and volumes decrease.
>If people stopped buying things from far away that aren't really really necessary, maybe that will also reduce fuel use.
From what I understand, shipping long distances is super efficient per unit goods transported; the ship that drags whatever it is you buy across the ocean produces less carbon (per unit transported) than the truck from the port to your store, which emits less carbon per unit transported than your car going from the store to your home.
If you want to save fuel, argue for good public transit, higher density housing and mixed use zoning. Or, more controversially, perhaps look into efficient delivery services that deliver a lot of groceries to people in the same area.
I mean, to be clear, I'm not saying that pollution caused by larger transport should be ignored; it's probably easier to deal with pollution on a giant ship than on a thousand little cars, but my point is just that you should go after the biggest problem, that we live in low density areas and drive everywhere.
Note, people say there are a lot of economic arguments for buying local, though I personally think that is harder to analyze than simple carbon emissions, and I'm not addressing that here.
http://www.cleanmetrics.com/pages/ch9_0923.pdf
"Figure 9.3 also shows that the most energy-intensive transit link is often the last one–driving to the store. This is not surprising, because other studies, such as those by Browne et al. (2005) and Van Hauwermeiren et al. (2007), find that this link canbe the most carbon intensive even in European countries where consumers are tra- ditionally more energy conscious than their U.S. counterparts."
From what I understand, shipping long distances is super efficient per unit goods transported; the ship that drags whatever it is you buy across the ocean produces less carbon (per unit transported) than the truck from the port to your store, which emits less carbon per unit transported than your car going from the store to your home.
If you want to save fuel, argue for good public transit, higher density housing and mixed use zoning. Or, more controversially, perhaps look into efficient delivery services that deliver a lot of groceries to people in the same area.
I mean, to be clear, I'm not saying that pollution caused by larger transport should be ignored; it's probably easier to deal with pollution on a giant ship than on a thousand little cars, but my point is just that you should go after the biggest problem, that we live in low density areas and drive everywhere.
Note, people say there are a lot of economic arguments for buying local, though I personally think that is harder to analyze than simple carbon emissions, and I'm not addressing that here.
http://www.cleanmetrics.com/pages/ch9_0923.pdf
"Figure 9.3 also shows that the most energy-intensive transit link is often the last one–driving to the store. This is not surprising, because other studies, such as those by Browne et al. (2005) and Van Hauwermeiren et al. (2007), find that this link canbe the most carbon intensive even in European countries where consumers are tra- ditionally more energy conscious than their U.S. counterparts."
Well, which would have more impact, not shipping electronics from China across the Pacific, or not shipping exotic fruits? I don't actually know, but I'm willing to wager that global supply chains for consumer goods outweighs that for foreign fruits.
I expect you are correct but not because the sail is not efficient enough, just that it would be impossible to implement without displacing several stacks of cargo containers. Thus the energy savings would be offset by a loss of cargo revenue. Not to mention the additional challenges of operating near loading and offloading cranes.
Potentially just makes a better testbed. As the article mentions, it is planned to add this to a couple of oil tankers.
https://en.wikipedia.org/wiki/Cargo_ship#Size_categories
The air draft of a ship is a limited resource, as if a ship is too high above the water, it won't be able to pass under bridges and other port infrastructure. It strikes me that adding 24 meters to this might not be something cargo ships are willing to do.
See, for example, https://www.joc.com/port-news/us-ports/port-new-york-and-new... , where $1.3B is being spent to raise a bridge 64 feet to accompdate larger ships. That's 19 meters, which is in the ballpark of 24.
The air draft of a ship is a limited resource, as if a ship is too high above the water, it won't be able to pass under bridges and other port infrastructure. It strikes me that adding 24 meters to this might not be something cargo ships are willing to do.
See, for example, https://www.joc.com/port-news/us-ports/port-new-york-and-new... , where $1.3B is being spent to raise a bridge 64 feet to accompdate larger ships. That's 19 meters, which is in the ballpark of 24.
Some of the rotors are retractable.
Please note this ship was quite unique to begin with: it's a 5-year-old 12-deck cruiseferry that burns gas instead of oil. https://en.wikipedia.org/wiki/MS_Viking_Grace
Here's an image of the ship with the new rotor sail on top: http://www.maritimeherald.com/2017/cruise-ferry-viking-grace...
Here's an image of the ship with the new rotor sail on top: http://www.maritimeherald.com/2017/cruise-ferry-viking-grace...
the physics involved must be really interesting. Visually, the "sail" looks incredibly tiny compared to the size of the ship and the size of sails on sailing ships of earlier ages
There are also large kite systems for ships, taking advantage of stronger winds at higher altitudes. Savings of up to 20% fuel.
https://en.wikipedia.org/wiki/SkySails
http://www.dailymail.co.uk/news/article-5186905/Cargo-ships-...
https://en.wikipedia.org/wiki/SkySails
http://www.dailymail.co.uk/news/article-5186905/Cargo-ships-...
Simple video that shows how the Magnus force works: https://m.youtube.com/watch?v=O6JdMSpiIqU
Thanks! Seeing this reminded me of this basketball being dropped off the edge of a dam:
https://m.youtube.com/watch?v=PM9vnEWmA1c
https://m.youtube.com/watch?v=PM9vnEWmA1c
And an RC airplane using that principle: https://www.youtube.com/watch?v=K6geOms33Dk
Wikipedia link: https://en.m.wikipedia.org/wiki/Rotor_ship
“Flettner constructed an experimental rotor vessel; October 1924”... Not practical. Renewed interest this century, improved design. New ships: Viking Line to reduce fuel consumption up to 15%. Maersk to start testing 2018. Norsepower to cut 7-10% of fuel cost in big tankers.
Why one? Why not 5 or 10? (since the savings quoted are between 10% to 20%)
I realize this must be a test, but I’m surprised they don’t discuss plans for multiple. Are the projected savings actual or “theoretical”?
I realize this must be a test, but I’m surprised they don’t discuss plans for multiple. Are the projected savings actual or “theoretical”?
It's not a test of the technology. This has been tried many times before. Perhaps most famously by the Cousteau Society, with their expedition ship 'Alcyone' built in the mid 80's. It used two, and they called them Turbosails.
I was fortunate enough to have been given a tour when I was a child and the ship visited Sydney.
https://en.wikipedia.org/wiki/Turbosail
http://colaco.freeshell.org/downloads/alcyone/zoom_alcyone_c...
https://en.wikipedia.org/wiki/Alcyone_(ship)
I was fortunate enough to have been given a tour when I was a child and the ship visited Sydney.
https://en.wikipedia.org/wiki/Turbosail
http://colaco.freeshell.org/downloads/alcyone/zoom_alcyone_c...
https://en.wikipedia.org/wiki/Alcyone_(ship)
I have a crazy story about that ship. I transited on that vessel in March 2002 from the endeavor museum to a vip event on the other side of manhattan. The crew forgot to notify Port control and we were swiftly intercepted by the coast guard. They had guns drawn and nearly boarded us. The sails looked like missle silos and we were almost in sight of ground zero only a few months after 9/11. The situation was exacerbated by the French crew monitoring international channel 16 not US channel 16. So they never responded to the USCG hailing them.
I think some ships have two, but the reason you can't stuff a bunch in there is the same reason planes usually have only one wing.
most planes have 5 wings under any reasonable accounting.
Most planes have only two wings. Wings producing lift and keep the plane up.
Two little horizontal 'wings' at the back are horizontal stabilizers. They are like wings but installed upside down (they produce negative lift and push the tail down).
Two little horizontal 'wings' at the back are horizontal stabilizers. They are like wings but installed upside down (they produce negative lift and push the tail down).
Oh right that’s why ships have only one sail, and wind farms have only one windmill, because same reason as planes. Good point.
Where can I see the ships with two?
Where can I see the ships with two?
A sailing vessel with a single sail still has two foils for generating lift. The other 'wing' is the boats keel. It is net force from both that propels a sailing boat forward.
Doubt it is purely based on pressure, as the diagram insinuates. Like the lift effect of an aerofoil, much of it comes from entrainment: the phenomenon that the device is basically causing the moving air to stick to it and then "throwing" that air at an altered angle which generates thrust.
Stupid question- but there is are huge currents under water- could they be harvested for additional forward motion?
https://en.wikipedia.org/wiki/Ocean_current
https://en.wikipedia.org/wiki/Ocean_current
I wonder if we would be better off sending stuff by rail, at least for Europe we are connected by land to China.
From what I have come to understand sea based goods transportation isn’t nearly as subject to the political whims of a nation as land based travel. That’s one of its main advantage sis that even if say nation A has an issue with nation C nation A can still sell goods to nation B without issues of C blocking their travel
With land based transport, it is wholly dependent on a nation state to be cooperative. Thst isn’t to say it wouldn’t be a solvable problem and I think generally most nations would see the benefits quickly but it only takes say the Russians having a fallout with the US (I’m the case of ever building that mythical Alaska to Russia bridge in the Bering sea to interconnect the continents) for them to cut someone off. Or let’s say a middle eastern terrorist group decides to blow up trade tracks that lead from China and great Asia into Europe.
Most of that political strife is safely ignored via sea trade. Honestly I believe that’s what holds back globally connected rail which I think has a cheaper long run cost and could more reliably deliver goods in a perfect world
I don’t have sufficient research to back this up at the one time though I simply just remember reading about this a few years back
With land based transport, it is wholly dependent on a nation state to be cooperative. Thst isn’t to say it wouldn’t be a solvable problem and I think generally most nations would see the benefits quickly but it only takes say the Russians having a fallout with the US (I’m the case of ever building that mythical Alaska to Russia bridge in the Bering sea to interconnect the continents) for them to cut someone off. Or let’s say a middle eastern terrorist group decides to blow up trade tracks that lead from China and great Asia into Europe.
Most of that political strife is safely ignored via sea trade. Honestly I believe that’s what holds back globally connected rail which I think has a cheaper long run cost and could more reliably deliver goods in a perfect world
I don’t have sufficient research to back this up at the one time though I simply just remember reading about this a few years back
This is going to happen, potentially: https://en.wikipedia.org/wiki/Trans-Asian_Railway
Of course, it will go through Russia and Belarus. I’m not sure anyone will be too keen to rely on it absolutely.
Of course, it will go through Russia and Belarus. I’m not sure anyone will be too keen to rely on it absolutely.
I’m confused. Can they only operate this when the wind I perpendicular to the direction the ship wants to go?
I suppose it works like ordinary sails, but without decent trim - the shape of the hull and rudder counterbalance the perpendicular force and you steer slightly crosswind to compensate for drift.
You won't be able to go directly into the wind, as the forward component can't be too small.
I guess you need to spin it in the right direction unless you want to go backwards...
You won't be able to go directly into the wind, as the forward component can't be too small.
I guess you need to spin it in the right direction unless you want to go backwards...
Why would this be better than sails?
You mean compared to traditional sailboat sails? There don't seem to be products that would add them to traditional cargo ships or ferries. Probably blocked by the crew skills and effort needed to operate and maintain them, as well as more invasive structural demands placed on the ship.
The only other recent sail boost attempt is kite based approach: https://www.treehugger.com/cars/cargo-ship-with-kites-first-...
A cynic might of course also propose that you can't get public research money or patents for a product based on traditional sail...
The only other recent sail boost attempt is kite based approach: https://www.treehugger.com/cars/cargo-ship-with-kites-first-...
A cynic might of course also propose that you can't get public research money or patents for a product based on traditional sail...
”as well as more invasive structural demands placed on the ship.”
Why would that be the case for a sail that gives the same fuel reduction? Are these rotors less impacted by sudden gusts of high wind speed than traditional sails?
Why would that be the case for a sail that gives the same fuel reduction? Are these rotors less impacted by sudden gusts of high wind speed than traditional sails?
A rotor sail is just a tube that rotates. Regular sails need complicated rigging.
Why? Without additional arguments on the table, I would think the force exerted on the wind-catching structure would be equal between sails and these rotors, for equal efficiency gains.
That load has to go somewhere. Rigging is a way to do so with traditional materials, but nowadays, a sturdier mast without rigging is possible.
(Rationale: if the ‘mast’ hidden in these rotors can be made strong enough, we can also create a mast holding a traditional sail taking the same load)
That load has to go somewhere. Rigging is a way to do so with traditional materials, but nowadays, a sturdier mast without rigging is possible.
(Rationale: if the ‘mast’ hidden in these rotors can be made strong enough, we can also create a mast holding a traditional sail taking the same load)
Rigging is not about strength. It's about adjusting the shape, size, angle, and trim of the airfoil that is the sail. Sails are not just vertical parachutes, those would be useless in anything except straight tailwind. Sails are vertical wings. They can provide propulsion (lift) even in headwind.
Have you ever been sailing?
Does that matter? It’s all physics. If you think my logic is incorrect, point out where.
Rotor sails are relatively insensitive to foul weather and wind direction.
If you had any experience with sailing, especialy on the high seas in a variety of conditions, you'd have a much better understanding of the problems.
If you have the means to go out on the sea in a sailboat, I highly recommend it. Especially for someone with a STEM background, it's actually a quite interesting activity.
If you had any experience with sailing, especialy on the high seas in a variety of conditions, you'd have a much better understanding of the problems.
If you have the means to go out on the sea in a sailboat, I highly recommend it. Especially for someone with a STEM background, it's actually a quite interesting activity.
Modern, mechanical sails have been tried, too. The Japanese Nippon Kokan built ships like this in the 1980's:
http://collections.rmg.co.uk/collections/objects/66022.html
Apparently the savings in fuel consumption were ~10%, so not really worth the hassle. Viking Grace's new tube may actually be more effective if the 20% of fuel savings can be trusted, besides being simpler to operate and less intrusive.
http://collections.rmg.co.uk/collections/objects/66022.html
Apparently the savings in fuel consumption were ~10%, so not really worth the hassle. Viking Grace's new tube may actually be more effective if the 20% of fuel savings can be trusted, besides being simpler to operate and less intrusive.
Weather and wind direction variance prevents traditional sails from being practical. They barely even need a crew on these ships, and can pretty much ignore the prevailing wind direction. There's insufficient economic incentive to incur the significant costs of operating with sails.
There's a reason the age of sail is in the past, it couldn't even compete with steam.
There's a reason the age of sail is in the past, it couldn't even compete with steam.
I think the big argument against more efficient cargo ships is that they have long lifetimes and new ones aren’t built that fast.
I think we should built giant cargo tugs with wind and solar power. They can just hook up to a cargo ship in the high seas and tow it. That way we can keep the existing ships.
I think we should built giant cargo tugs with wind and solar power. They can just hook up to a cargo ship in the high seas and tow it. That way we can keep the existing ships.
high seas and tow it
I think this phrase would frighten any professional sailor. Tugboats don't really operate very far from shore, for good reason. You don't want to be in a storm and see the giant load to which you are strapped passing you and starting to roll.
I think this phrase would frighten any professional sailor. Tugboats don't really operate very far from shore, for good reason. You don't want to be in a storm and see the giant load to which you are strapped passing you and starting to roll.
If the thing that is towed is a conventional ship, it can use its own power in such conditions?
The point is, the most dangerous points in the operation of a vessel are those when more than one vessel is in close proximity to another because it adds the extra problem of "we need to not hit the other guy" onto an already formidable stack of problems to be solved.
This isn't like programming where a little complexity can be handled at a trivial cost. Even if the tugs were say, AI controlled, so that endangering other sailors wasn't an immediate concern, these tugs would still be potential sources of catastrophic damage when fighting inclimate seas due to the size and materials they would have to be made from to actually make any significant difference in getting a fully laden cargo ship from A to B.
Tugs are justifiable on inland waters or near ports because they are generally there to replace the ship they are towing's need or means to manoeuvre, enabling smaller, tighter movements than the ship is capable of under its own power. It also enables a transfer of control from a helmsman who may not know the particulars of a port or waterway at that time, to that of a local who's only job is juggling ships in that port day in and day out.
Think of tugs as Valets. You don't want to deal with the hassle of dealing with one on the open sea, and it is guaranteed one you bring along with you won't know anything useful about where you are going. Best to just let the destination worry about it.
The best approach would be to develop a system that could be relatively quickly integrated into current hulls during a quick refit, or to start designing new hulls with the system from the get go. The physical world doesn't take kindly to hack jobs.
Disclaimer: not a sailor, just fascinated by logistics. If I have made any undue assumptions, please feel free to correct me.
This isn't like programming where a little complexity can be handled at a trivial cost. Even if the tugs were say, AI controlled, so that endangering other sailors wasn't an immediate concern, these tugs would still be potential sources of catastrophic damage when fighting inclimate seas due to the size and materials they would have to be made from to actually make any significant difference in getting a fully laden cargo ship from A to B.
Tugs are justifiable on inland waters or near ports because they are generally there to replace the ship they are towing's need or means to manoeuvre, enabling smaller, tighter movements than the ship is capable of under its own power. It also enables a transfer of control from a helmsman who may not know the particulars of a port or waterway at that time, to that of a local who's only job is juggling ships in that port day in and day out.
Think of tugs as Valets. You don't want to deal with the hassle of dealing with one on the open sea, and it is guaranteed one you bring along with you won't know anything useful about where you are going. Best to just let the destination worry about it.
The best approach would be to develop a system that could be relatively quickly integrated into current hulls during a quick refit, or to start designing new hulls with the system from the get go. The physical world doesn't take kindly to hack jobs.
Disclaimer: not a sailor, just fascinated by logistics. If I have made any undue assumptions, please feel free to correct me.
You wouldn't want to be in a conventional tug at all in open ocean conditions, regardless of the tow or no tow at all.
You would need a new kind of tug, more resilient to waves and storms, with crew quarters, room for provisions and all of the life saving gear a normal open ocean ship has. You may as well build a new cargo ship.
You would need a new kind of tug, more resilient to waves and storms, with crew quarters, room for provisions and all of the life saving gear a normal open ocean ship has. You may as well build a new cargo ship.
Not to say that the argument to have tugs pull barges offshore is sound, but high sea tugs exist: https://en.wikipedia.org/wiki/Abeille_Bourbon
So they didn't remove the propeller(s)? That's going to be a serious drag in a towing situation. And no, you can't just switch them on and off; they weigh many tons.
It's possible to retrofit existing ships with some of the new approaches. Just over a decade ago the company SkySail produced a kite like system that could be added to existing cargo ships to achieve multiple %age fuel savings.
There's a couple of interesting quotes on the wiki page (https://en.wikipedia.org/wiki/SkySails):
> There’s a structural problem slowing down the process: ship owners (who have to make the investment) often don’t pay for the fuel – that’s the charterer’s duty. The charterer on the other side doesn’t charter the ship for long enough a period to make low-carbon technologies pay back. — Henning Kuehl, head of business development at SkySails
and
>Fuel costs mostly get passed onto the shipper so we see little use in installing potentially expensive, untested technology to which we see no other benefit. Basically I am interested but will not be the first to try it on a large scale. — Anonymous ship owner
So essentially it looks like the incentives are all in the wrong places for such technology to see rapid implementation.
There's a couple of interesting quotes on the wiki page (https://en.wikipedia.org/wiki/SkySails):
> There’s a structural problem slowing down the process: ship owners (who have to make the investment) often don’t pay for the fuel – that’s the charterer’s duty. The charterer on the other side doesn’t charter the ship for long enough a period to make low-carbon technologies pay back. — Henning Kuehl, head of business development at SkySails
and
>Fuel costs mostly get passed onto the shipper so we see little use in installing potentially expensive, untested technology to which we see no other benefit. Basically I am interested but will not be the first to try it on a large scale. — Anonymous ship owner
So essentially it looks like the incentives are all in the wrong places for such technology to see rapid implementation.
That's not practical, the high sea can be incredibly dangerous, even with modern nautical technology. Most tech out there is informational, there's very little you can actually do if the ocean decides to throw a tantrum.
Also, ships don't just go to waste when they reach EOL, if they do. They get scrapped, similar to a car I guess, but a lot of material can be reused or recycled or sold, and so on.
Anyways yeah, giant tugs, not a good idea. Not a good use of resources.
Also, ships don't just go to waste when they reach EOL, if they do. They get scrapped, similar to a car I guess, but a lot of material can be reused or recycled or sold, and so on.
Anyways yeah, giant tugs, not a good idea. Not a good use of resources.
>I think we should built giant cargo tugs with wind and solar power. They can just hook up to a cargo ship in the high seas and tow it. That way we can keep the existing ships.
This is the reverse of when managers make ridiculous assumptions about programming that stem from a complete lack of understanding.
Towing big ships is hugely dangerous.
This is the reverse of when managers make ridiculous assumptions about programming that stem from a complete lack of understanding.
Towing big ships is hugely dangerous.
It seems like there’s not enough surface area to capture much wind energy.
Wouldn't just not having something as superfluous as luxury cruise ship lines reduce fuel consumption even more?
How I know this article wasn't written by an AI
"
In addition to reduced strain on the enviornment, the rotary sail has a strong financial incentive for. "
Cargo shipping is ruthlessly cost-competitive, and fuel is currently 50-60% of costs. [1] With the new regulations that percent will increase.
Still it is telling the rotor sail in the example is on a passenger ship (where it has more PR value) not a cargo ship. That says to me the cost savings are really not there yet. Probably even stronger clean shipping rules are required before this kind of thing will be cost effective.
[1] https://www.morethanshipping.com/fuel-costs-ocean-shipping/