Wind Powered Freighters Return

thatoneguyfromphoeni writes "It appears that sails could return to the ocean's freighters soon. Newsweek is reporting on a technology to assist with cross-ocean travel. From the article: 'SkySails' system consists of an enormous towing kite and navigation software that can map the best route between two points for maximum wind efficiency. In development for more than four years, the system costs from roughly $380,000 to $3.2 million, depending on the size of the ship it's pulling. SkySails claims it will save one third of fuel costs.'"

Welcome to the 80's

[Warshadow (132109)]

During the oil crisis in the early 80's they worked on this. I'm fairly sure one company did add sails to a ship or two and did see a reduction in fuel consumption.

Also Popular Mechanics ran an article on this like 4 months ago. In fact it was on the cover of that issue.

The Flettner rotorship

[PapayaSF (721268)]

The early helicopter designer Anton Flettner [wikipedia.org] made an interesting attempt in the '20s to harness wind power for ocean travel. The Flettner rotorship Bruckau [efluids.com] used two tall, rotating cylinders to harness the Magnus Effect. It worked, but unfortunately turned out to be less efficient than normal propulsion [tecsoc.org].

Re:Welcome to the 80's

[fm6 (162816)]

Indeed, in the 80s, lots of companies hopped on the alternative energy bandwagon. Exxon seemed to be operating on the assumption that they'd be out of the oil business soon. They bought into high tech in a big way, including the company I was working for [warthman.com]. One person I met from another Exxon subsidiary talked about new battery technology they were working on. This was supposed to be a new business for all those Exxon gas stations that soon wouldn't have any gas: swapping out depleted batteries in electric cars.

Then oil prices came back down, those batteries turned out to be harder to design than they thought, and Exxon discovered they weren't very good at managing high tech. Back to business as usual. And here we are again...

Re:Welcome to the 80's

[Danga (307709)]

Also Popular Mechanics ran an article on this like 4 months ago. In fact it was on the cover of that issue.

I was trying to remember where I somewhat recently read about this technology and thank you for reminding me that it was in Popular Mechanics.

I can't find a link to the Popular Mechanics article (I think it was in the february 2006 issue) but you can read more about this technology here http://alt-e.blogspot.com/2005/02/hybrids-hybrid-b oats-hybrid-ships-and.html [blogspot.com] and the following link has some more information as well as some interesting pictures/diagrams http://www.primidi.com/2005/03/07.html [primidi.com] .

It is pretty amazing how much more efficient the sails can make a ship, from the last link I mentioned:

"cargo vessels can increase their speed by a minimum of 10% -- in the example given speed is increased yet by 2.25 bends, equaling 15%. Alternatively by using the SkySails propulsion fuel savings of up to 50% can be implemented."

It showed that using 1200 litres of fuel per hour a normal ship would cruise at ~15.5 knots and a skysail enhanced ship would cruise at close to 18 knots, not too bad of a speed gain. If the skysail ship wanted to cruise at 15.5 knots instead then fuel consumption would drop from 1200 litres per hour to around 550. That is just awesome and I really hope this goes into wide use where it is feasable to use it.

I wonder about the article photo

[Frequency Domain (601421)]

The artist's conception picture in the article shows the bow as the point of attachment for the parasail. I suspect that would make steering much more difficult, compared to hooking the parawing near the center of mass for the ship.

Re:I wonder about the article photo

[nacnud75 (963443)]

The parasail behaves very differently to a normal triangular sail or even a jenica. You move the parasail constantly through the air in a figure of eight to generate power. Also these ships are likely to follow the trade winds where the wind normally comes from the stern, therefore attaching the sail to the bow won't be a problem as most of the time the ship would be traveling on a broad reach or run.

Re:I wonder about the article photo

[MathFox (686808)]

It takes some time to get a supertanker turning... but once they turn it takes significant time to stop the rotation. Rotational inertia can work against you.
Having the pulling force closer to the center of the ship will decrease the needed rudder force for correction; using the rudder creates friction, so that's best avoided. Another advantage of having the ropes mid-deck makes it possible to lower the kite on deck, much more convenient than fishing it out of the waves after use.

Re:Tugboat attachment points

[alshithead (981606)]

Most newer freighters and tankers can pretty much dock themselves. The have bow and stern thrusters that make them very maneuverable at low speed. These days tugs are more of a backup system for docking ships. They'll tie on and sit at the ready but the pilot on the ship is doing the docking using the bow and stern thrusters.

Presumably that one-third savings is over...

[Assmasher (456699)]

...the course of a *different* route than if the ship is entirely under power; ergo, use the sails and you need to chart a different, likely less direct, course for the ship. I wonder what the average increase in distance for a route is?

Likely this will still have value even if just used when the wind is positioned conveniently. Certain legs of round trips are certainly likely to benefit greatly from sail power.

Very cool. I'd certainly love to see that out on the ocean.

What was old is new again

[iminplaya (723125)]

Sorry, this [bookrags.com] is the best I could find. I'm just not that good with this Google thing. I was looking for a picture, but FTL:
Rising fuel prices during the 1970s prompted the development of a new technology that used sails shaped like aircraft wings turned on end to take some of the burden off the engines and save fuel. Slightly curved to form a wing shape, these sails were attached to a mast that could pivot and locate the best angle for the sail to catch the wind. Once the computers set the mast at the best angle to the wind, the sail created the same "lifting" force that an airplane's wing generates, except that the force pushed the ship along the water. However, this system did not always prove to be efficient for extremely large vessels. I thought what I saw was that the mast itself was a rigid aerodynamic sail.

While it is good for the environment...

[irritating environme (529534)]

One of the things I was looking forward too as gas/oil prices skyrocketing was a decrease in offshore manufacturing. Economics and exploitation of slave labor may say that it's cheaper to manufacture something and then send it 2,000 miles over ship rather than manufacture locally, that entire equation depends on cheap oil.

Stuff like this will save oil and carbon outputs, but really just allows the same wasteful economic system. I have mixed emotions.

Ahh, the military will probably ban them b/c it disrupts their radars.

Re:While it is good for the environment...

[Stoutlimb (143245)]

Not all cheap labour is slave labour. In fact, "slave labour" as you call it, is vastly in the minority. Most shipping just takes advantages economic differences between countries. (ie cheap to make in one country, expensive to make in another.) "Slave labour" is the boogeyman people drag out to frighten people when they are against international trade for whatever reason.

While deplorable, it's hardly the standard.

Re:While it is good for the environment...

[sockonafish (228678)]

Wasteful? If it's cheaper to make a good elsewhere and then ship it than to make it locally, it's more wasteful to produce that good locally.

Economics classes should be required to graduate high school.

Re:While it is good for the environment...

[ThosLives (686517)]

Perhaps they should also require Advanced Economics.

'Waste' doesn't necessarily equate with price or cost. For instance, it is profoundly wasteful that, for instance, in the US we have non-refillable containers for just about every food product we purchase. This is very inexpensive, but is very wasteful - there is no technical reason why a store could not have a sanitary 2-liter filling station where you just take the same bottle over and over to obtain your beverage of choice. This would actually be less expensive in the long run, but it would cost people who make bottles their jobs, etc. etc.

Again, remember that cost does not necessarily match with waste. In fact, generally less expensive alternatives cost less than their less-wasteful alternatives - at the initial investment stage. However, the long-term costs are always lower with less waste.

Re:While it is good for the environment...

[dragons_flight (515217)]

Oceanic shipping is already incredibly efficient and only accounts for a few percent of the cost of most goods shipped that way. For example, a supertanker only adds 2 cents [wikipedia.org] to the cost of a gallon of gas. It would take a very radical change in the cost of oil to have any significant impact on the economic viability of overseas manufacturing.

I'm skeptical

[Jeff Molby (906283)]

Here is a video [skysails.info] from their site. This is obviously a prototype, so they have a LOT of scaling to do. Plus, the only time you see the boat (yes, I said boat, not ship) moving with any significant speed, you can't see the rear, so it's safe to assume that its engine is assisting.

Maybe but cost didn't kill the clippers

[wbean (222522)]

Maybe, but the real reason sailing ships went out of use wasn't the cost of transporting the cargo. Remember that sailing ships didn't need space for engines or fuel; and, by the end of the 19th century they were sailed by very small crews. They were always the cheapest way to get cargo from one point to another. What killed them was the unreliability of their passage times: In order to gurarantee a steady supply of a commodity you had to have big wharehouses at each end. Steamships eliminated the wharehouses so the end-to-end cost was less. Just in time inventory anybody?

Re:Maybe but cost didn't kill the clippers

[Jeff DeMaagd (2015)]

I don't see how this applies, this system is using wind as a supplement, not as its main or only source of propulsion. I really don't know how feasible this is, but it would be interesting to try. It assumes that the wind is blowing faster than the ship would move under its own power, and assumes the ship isn't fighting the wind. Whether the useful wind makes up for the cost of buying and operating some sort of sails is unknown.

Re:don't forget piracy/war...

[Firethorn (177587)]

It's unclear that war/privateers and piracy are much of a problem crossing the Pacific right now.

Not in the Pacific, but there's issues in the caribbean, around Africa(Somolia), and certain sections of the middle east.

What protects the giant cargo ships is that they're so big it'd take a ship of equal size to steal the cargo, and even pirates could get ahold of a ship that size, it'd be rather trivial to track by satellite, and most of the navies of the world consider pirate suppression part of their core duties. If there's nothing else more important going on, even an American Aircraft carrier will divert to chase suspected pirates.

Most pirates today mostly steal the crew's effects, maybe part of a container, and sometimes take the crew hostage for ransoms.

You don't hear much about it, but cruise liners, which you'd think would be tempting targets, are also among the fastest, especially when they turn all the engines up. With the smaller boats pirates tend to use, they either lack the speed or the endurance to catch them. Even if they do, it has a huge crew that's also trained(and armed) to keep pirates from getting aboard. That and the moment they spot pirates they'll be calling for help, and remember how I mentioned most navies like catching pirates? Pirates chasing a cruise liner will have every naval asset that has a prayer of intercepting will be applying full power to the engines.

Walker Wing Sail seems more practical

[Locutus (9039)]

The Walker Wing Sail system was designed in the 70s when fuel was 'expensive' and the idea was to outfit freighters with the Wing Sails to help reduce fuel costs. Unfortunately, once the fuel 'shortages' of the 70's went away, Mr Walker found it very difficult to sell his systems. He started making his own Trimarans when no boat builders would license his design and build boats using it. But finacially solid orders were too few and only a handful of his boats were made utilizing the Wing Sail design. Some are still afloat today.

http://www.lusas.com/case/composite/wingsail.html [lusas.com]

So I think the Walker Wing Sail makes more sense than this para-sail system.

LoB

Landlubbers.. gotta love landlubbers..

[by Anonymous Coward]

Those of you who have never been out of littoral water (bays, rivers, harbors, canals, lakes, etc) please do a little research before deep-sixing an idea.

The largest sailing ships (of the Chinese Great Fleet) ever made approached size of WWII aircraft carriers (Enterprise/Lexington/Yorktown size) and measured their mainsails in fractional acreage.

I've been a professional blue-ocean sailor for several years. Calm seas and no wind are two things you rarely see unless you are in a brown-water (littoral waters) environment. One of the reasons the current shipping lanes are shaped the way they are is due to great-circle fuel efficiency. The older shipping routes followed the areas of regular wind "down where the trade winds blow" and were essentially 'free'. A tradeoff of a 5% longer route for a deduction of 5% in fuel costs is something that any shipping agency would be willing to consider. There is a print-out on our bridge that shows fuel consumption ($$ also) per hour per engine at the 'sweet spots' throttle settings. My captain much prefers to not burn more fuel than he needs to.

Re:How big?

[Cromac (610264)]

At this site http://www.bath.ac.uk/~ccsshb/12cyl/ [bath.ac.uk] the most powerful ship diesel running at its most efficient speed burns 1,660 gallons of heavy fuel oil per hour. Even using the cheap, nasty fuel these ships burn that's a big expense.

According to http://www.skysails.info/index.php?id=66&L=1 [skysails.info]

Increasing efficiency using ship diesel has almost reached its maximum potential and is also extremely expensive. According to the calculation of an expert on ship propulsions, shipping companies would have to invest up to 500,000 Euros in order to reduce a ship's fuel consumption by 1%. Fuel savings of 5% would be a fantastic performance for ship owners, according to Niels Stolberg, managing partner of Bremen-based shipping company Beluga Shipping GmbH.

To get an increase of 35% (the max claimed by SkySails) would mean a 3.5 million euro investment, that's a lot of crewman salaries even at union wages and less than the Skysails implementation would cost.

They have some interesting performance calculations on their website too about how much sail produces how much energy. http://www.skysails.info/index.php?id=89&L=1 [skysails.info]

Re:These guys must have solved a major problem

[richdun (672214)]

Amusing, but in all seriousness, I'd love to see how well this stuff can plot courses through winds. This kind of thing could also be great for space travel - both for plotting through solar winds and gravitational assists (or both at once). If it's that much better at plotting through winds than whatever else we've had up until now, maybe it's also better than whatever orbital navigation plotting we have rigth now.

Re:These guys must have solved a major problem

[richdun (672214)]

And only on Slashdot could someone make such a worthless comment.

Solar wind, gravitational plots, and air winds all represent very subtle and dynamic forces that can't be directly controlled (unlike aerodynamic forces and engine thrust, for instance). If these guys are able to accurately navigate through winds and do it all more efficiently (and faster, hopefully) than currently available, the navigational community could apply their methods to a lot of different methods of navigation. It's like finding a better turbine blade - jets, powerplants, and watercraft could all benefit.

Re:Wind assist

[ray-auch (454705)]

I'd just have to wonder about the incredible tension the kite's main lead would be under. We're talking HUGE forces here. One of those "if it snaps, someone's gonna die" kind of tensions.


can't be much different to towing the ship with a tug - which is pretty common.

forces on anchor cables and mooring lines are also likely to be pretty similar.

you are right on the "someone's gonna die" level on tension (well known with eg. mooring lines), but it's going to be a manageable risk because it is already managed with ships of this size.