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Rotor sail helps Finnish ferry Viking Grace reduce fuel consumption
- georgeecollins 8y agoHow 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. "
- doitLP 8y agoSimple video that shows how the Magnus force works: https://m.youtube.com/watch?v=O6JdMSpiIqU https://m.youtube.com/watch?v=O6JdMSpiIqU
- tensafefrogs 8y agoThanks! 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
- icebraining 8y agoAnd an RC airplane using that principle: https://www.youtube.com/watch?v=K6geOms33Dk https://www.youtube.com/watch?v=K6geOms33Dk
- trothamel 8y agohttps://en.wikipedia.org/wiki/Cargo_ship#Size_categories 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-jersey/bayonne-height-restriction-removal-aids-ny-nj-port-navigation_20170425.html 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.
- chuckledog 8y agoSome of the rotors are retractable.
- chuckledog 8y agoWikipedia link: https://en.m.wikipedia.org/wiki/Rotor_ship 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.
- mrfusion 8y agoWhy would this be better than sails?
- fulafel 8y agoYou 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-trans-atlantic-trip-a-success.html 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...
- Someone 8y ago”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?
- Sharlin 8y agoA rotor sail is just a tube that rotates. Regular sails need complicated rigging.
- Someone 8y agoWhy? 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)
- mrfusion 8y agoI 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.
- jessaustin 8y agohigh 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.
- jononor 8y agoIf the thing that is towed is a conventional ship, it can use its own power in such conditions?
- ehnto 8y agoYou 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.
- nherment 8y agoNot 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 https://en.wikipedia.org/wiki/Abeille_Bourbon
- jessaustin 8y agoSo 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.
- dzdt 8y agoCargo ships are currently burning the dirtiest fuels available -- so-called bunker fuel. Regulation is finally forcing a degree of cleanup by 2020, limiting sulfer emmissions. 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/ https://www.morethanshipping.com/fuel-costs-ocean-shipping/
- Retric 8y agoMany 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.
- chiefalchemist 8y ago> "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.
- contingencies 8y agoBack 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.
- mitchty 8y agoThis has already been done for cargo craft. https://en.wikipedia.org/wiki/E-Ship_1 https://en.wikipedia.org/wiki/E-Ship_1
- paulsutter 8y agoWhy 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”?
- rileyphone 8y agoI 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.
- paulsutter 8y agoOh 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?
- satori99 8y agoA 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.
- ouid 8y agomost planes have 5 wings under any reasonable accounting.
- nabla9 8y agoMost 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).
- satori99 8y agoIt'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 https://en.wikipedia.org/wiki/Turbosail http://colaco.freeshell.org/downloads/alcyone/zoom_alcyone_canada.jpg http://colaco.freeshell.org/downloads/alcyone/zoom_alcyone_c... https://en.wikipedia.org/wiki/Alcyone_(ship) https://en.wikipedia.org/wiki/Alcyone_(ship)
- bufferoverflow 8y agoThere 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 https://en.wikipedia.org/wiki/SkySails http://www.dailymail.co.uk/news/article-5186905/Cargo-ships-KITES-help-slash-fuel-bills.html http://www.dailymail.co.uk/news/article-5186905/Cargo-ships-...
- tonyedgecombe 8y agoI wonder if we would be better off sending stuff by rail, at least for Europe we are connected by land to China.
- no_wizard 8y agoFrom 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
- rsynnott 8y agoThis is going to happen, potentially: https://en.wikipedia.org/wiki/Trans-Asian_Railway 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.
- kazinator 8y agoDoubt 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.
- justinator 8y agoWouldn't just not having something as superfluous as luxury cruise ship lines reduce fuel consumption even more?
- mrfusion 8y agoI’m confused. Can they only operate this when the wind I perpendicular to the direction the ship wants to go?
- kpil 8y agoI 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...
- mrfusion 8y agoIt seems like there’s not enough surface area to capture much wind energy.
- tuukkah 8y agoPlease 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 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-install-turbosail-for-hybrid-usage-of-wind-power/ http://www.maritimeherald.com/2017/cruise-ferry-viking-grace...
- lsc 8y agothe 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
- LifeLiverTransp 8y agoStupid 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