Next-gen cargo ships could use 164-foot sails to lower fuel use by 30%


April 24, 2012

Depiction of a cargo ship equipped with the Wind Challenger Project system of sails

Depiction of a cargo ship equipped with the Wind Challenger Project system of sails

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Of the world's nearly 45,000 cargo ships, many burn a low-grade bunker fuel in their engines and produce pollution equivalent to millions of automobiles. To help reduce that toxic load and keep the price of shipping freight reasonable, engineers at the University of Tokyo (UT) and a group of collaborators have designed a system of large, retractable sails measuring 64 feet (20 m) wide by 164 feet (50 m) high, which studies indicate can reduce annual fuel use on ships equipped with them by up to 30%.

"Using today's technology, it's possible to make big sails, and to control them automatically," UT professor Kiyoshi Uzawa told DigInfo. "Also, navigation technology includes networked maritime information and weather forecasting, so ships like this can travel safely. Using wind energy, as in old-fashioned sailing ships, is actually feasible."

Each five-segment collapsible sail, estimated to cost about US$2.5 million, will be hollow and constructed of durable, lightweight aluminum and fiber-reinforced plastic. Similar in shape to an aircraft wing in cross section, the sails can be positioned independently of one another to maximize thrust and, while at anchor or in bad weather, can telescope down in what is known as "vertical reefing."

Uzawa anticipates that, with basic research completed, the Wind Challenger Project (WCP) group will be able to consider construction of a reduced-size prototype in the next few years to fully prove the concept. If all goes as planned, sea trials could begin as soon as 2016. If results from scale model wind tunnel tests and computer simulations bear out in the real world, he believes the sails could pay ultimately for themselves in five to ten years.

Due to the varying nature of cargo vessels, it seems likely that the WCP technology will be better suited for low-slung bulk material ships (ore, grain, oil) than for sea container ships, say, which stack freight high above deck. The group is not short on innovation, however, so it'll be interesting to see how that issue is approached.

It appears that a new era of tall, greener ships could be just over the horizon.

Source: DigInfo via Akihabara News

Check out the DigInfo video below to learn more about the new sails.

About the Author
Randolph Jonsson A native San Franciscan, Randolph attended the U.S. Naval Academy at Annapolis, Maryland before finding his way to the film business. Eventually, he landed a job at George Lucas' Industrial Light + Magic, where he worked on many top-grossing films in both the camera and computer graphics departments. A proud member of MENSA, he's passionate about technology, optimal health, photography, marine biology, writing, world travel and the occasional, well-crafted gin and tonic! All articles by Randolph Jonsson

I'm not optimistic about the prospects. During the 1970s energy crisis, there was the similar Dynaship concept. That never went anywhere.


Anyone actually done the math? The mass of these vessels may be a little bit more than sails can handle.. Perhaps "cargo" ships can do it, considering the average weight of a container, but what about the true guzzlers of the ocean, that is, TANKERS?


Looks like the ship looses 30% of its container carrying capacity to its sails. Perhaps it should have a tender behind. A butty as the non-powered canal barges used to be called.

Andrew Kennedy

Actually, although I just left a comment about doing the physics involved, I have to say,there could not possibly be anything BUT a NET GAIN.. which will mean reduced costs, translating (hopefully) into reduced cost to us (the consumer)... Wow... Chinese goods are already at a botom, price-wise, how could they possibly go any lower.. although IF THEY DO NOT CHANGE, count it as a GOOD thing.. there is a push in China, to increase the wages, and working conditions, of the average worker.. this may just make it possible!!!! So i say support it!!


Good idea.

They might want to add other new ideas like maybe a "shark skin" type textured hull surface which would only add the extra weight and cost of a little extra paint.


It is a nice bit of public relations but the reality is that it would take more than 30 years to replace current cargo ships and that is supposing that 100% of the new ships adopt this technology. With the passenger ships using large sails of this type it has been a marketing gimmick with the sails in use only when entering or leaving a port and diesel power is used for the remainder of the cruise.

Cargo ships produce more particulate pollution with the bunker fuel sludge that they burn than all the cars, buses, trucks, and trains of the world combined. A side effect of global trade is an increase in cargo ship traffic and with it an increase in the type of pollution that has the greatest impact on global warming.


I think that this type of sail should be compared with kite sales: "SkySails has a cargo ship towing kite system of 8 and 16 tons, with future versions of 32 tons scheduled to be available in 2011 and 130 tons in the near future. A kite force of 8 tons is equivalent to a 600-1,000kW main shipboard engine. Running partly on wind power could save an average of 10-35% on the fuel used, and fuel consumption could be reduced by 50% in the best wind conditions."

Adrian Akau

Did anyone ever watch beyond 2000 back in the 80s? This is not new, maybe now they may actually do it, back then they were talking about using the propellor only as a back up during storms but ships have grown alot since then. Only 30% saving?


If ships all used this pollution would be far lower, Ship produce like they were the 6th largest country if they were a nation.

That said kites are better in most cases and high ships like container ones can't use any because of capsize risk.

Shipping cost are high and getting higher that along with recent Chinese labor, energy costs, Yuan increasing with American productivity and people switching to longer lasting quality products means the US is about to regain a nice amount of manufacturing.

I'm building 2kw windgens and match the Chinese on price but beat the pants off them in quality.


can't even get double hulled tankers. gods law: profit to the stockholder, no other concerns. call me pessimistic, but admit my reality orientation

Walt Stawicki

kitesails would be cheaper and work better in more situations


Do the sails go on top of the 6 or 7 storeys of containers? This is a boat which will not float.

Andrew Kennedy's idea of a sail powered tug makes real sense.

Guy Macher

It is unclear why this would be better than using fabric sails which would be far cheaper and much simpler technologically.

Michael Crumpton

Really Just think of the extra Maintenance. Aluminum sails that retract, just the right combination for corrosion. The manning of these vessels is so low that there would be no one that would be available to work on them. And what about hurricanes at sea These light weight sails would be blown off the decks. I work on a ship and we have a hard time keeping the gangways on in a storm. Just spend your money on LPG conversions. Quit burning BUNKER slops!!!!!!

Don O

I agree with Don O. Conversion to LPG would be the best alternative. As to the 30 year replacement cycle, this could be sped up considerably by countries and large natural gas producers paying help offset the costs. With the price of natural gas falling and the now huge glut of natural gas in places like the US and the Gulf States this could also be great way to stimulate the economies in dozens of countries. Start with the oldest ships and those on the drawing boards and work towards the middle in perhaps a 6 to 8 year turn time. Funding could also go towards conversion of bunker facilities at ports world wide. A "cash for bunkers" if you will.

Gary Tucker

They should also cover them with solar cells/solar panel while the are at it. Two bird one stone. Just hybrid the damn thing to diesel/electric. Or even go crazy with it and throw some hydro magneto dynamic drive system for less friction o_0

Mickens Renaudin

There are no conversion steps harvesting wind energy in this way, as opposed to rotating wings around a shaft in a stationary wind turbine feeding into the national grid. Enercon E-Ship-1 "sailing cargo ship" also promises 30-40% fuel savings, and is in operation as we speak.


They always compare the pollution generated by the ship as "equivalent to millions of automobiles" probably because if you compared it honestly to cars or trucks per ton mile hauled the ships would come off looking pretty good. Also how much pollution would be generated by refining the "low-grade bunker fuel" into high-grade fuel.

Nuclear electric propulsion would move the ships in a cost effective manner with a vast reduction in pollutants and while in port they could pump electricity into the grid.

You would have thought by now the engineers would know that aluminum is a bad idea in a saltwater environment.

Keeping a ship upright under sail requires, 1 a very deep weighted keel, 2 shifting ballast, or 3 gyroscopes. When only using sails under favorable winds I would use #2 in the form of sea water tanks mounted above the water line for ease and speed of discharge. ......................................................................................................................

re; Michaelc

Fabric sails do not hold the optimal shape well nor do they last better than aluminum in saltwater environment. But most importantly they require kilometers of ropes, pulleys, winches, and men to keep it all working.


Hello, This is great fun, but why not go for an All Electric System? No not solar or wind. Um, I have designed a new system that would need a tower half this size and would generate abundant energy on a trip that it could store the extra for sale at ports. No fuels. My True Green Energy Systems could be added to ships today and remove the fuel generators. Telescopic's could raise the towers to get underway. The towers would go down below the bridge. This tower system is just one that could power a ships needs abundantly. I have another that uses seawater and ---. The ship would have to be designed to "fit" that one. But it would be free energy as well. I designed that one when Japan's nuclear power plants melted down and the only source of energy was seawater for them, that I could figure anyway. Sure solar and wind, but those are not that reliable. Well, patents, copywrites and a prototype. Well, the prototype could be done in six months, just use what is out there for now... But, sails are a start, I guess. I have just designed the sails to add energy to the ships systems, can you see it two? Yes you can, look at it and add flexible solar skins to the surfaces. See, I knew you could see it too. The ships today have electric drive with fuel electric generators. Harniss those surfaces and you could add 10% to the fuel saved. Incorporate it into the manufacturing and your design to boost the hydrolic system a little... Well, fun stuff.

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