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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.'"
Scientists have been puzzling over the best route between 2 points for centuries, but the math has been too difficult.
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 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.
...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.
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Actually, this is not just a weird idea, but this is already in use by Beluga, an ocean carrier from Bremen/Germany.
(Funny that the image whose words I have to type in right now says 'seaport' (-: )
Sorry, this 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.
What?
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.
Hey, I'm just your average shit and piss factory.
The early helicopter designer Anton Flettner made an interesting attempt in the '20s to harness wind power for ocean travel. The Flettner rotorship Bruckau used two tall, rotating cylinders to harness the Magnus Effect. It worked, but unfortunately turned out to be less efficient than normal propulsion.
Q: What does the "B." in Benoit B. Mandelbrot stand for? A: Benoit B. Mandelbrot
Here is a video 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 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?
According to http://www.skysails.info/index.php?id=66&L=1
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
There is a company (mostly one guy, actually) - http://www.kiteship.com/ - that has been experimenting, testing, and building kites for boats of various sizes - including maxi sailboats and AC Boats, and has been testing much larger kites designed for ships. They look a little different from the kites designed for kiteboarding. It is not just materials, either - the shapes and techniques for setting and dousing have been big parts of it, as far as I understand.
The sky sails people seem to be trying to get on the hype bandwagon without having really built any sails, as far as I can tell.
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.
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.
I don't read AC A human right
Assuming that there needs to be something extra for directional stability, there are also :
- centreboards - which drop or hinge from inside the boat which can be retracted
- lee boards - which hinge from the side of the boat, one on each side. The one on the downwind side is usually lowered, hence the name. The most common example I can think of for these that you might know ( from paintings and such ) is Dutch sailing barges.
- bilge keels - short ( heightwise ) keels which run along the bottom of the boat away from the centreline ( along the bilges ), often oriented on a bit of outward angle vertically.
- water ballast - internal tanks which hold water to balance the boat. This is usually more to help with resisting the heeling/tipping force of the sails, but can be also be used to aid directional stability through good balancing.
All of these methods generally do not add any significant permanent draught to the boat. Many of these already have a strong tradition in freight vessels, for example sailing barges which also needed to be able to move through canals, but of course not on the scope of today's freighters. Although it would cost ( or just be impractical ) to adapt these sorts of things to existing vessels, you can imagine a future when wind assisted freighters might have these designed in from the start. There would not really be too much need for extra dredging etc. The wind provides free energy ( barring the cost of the equipment needed to harness that free energy ) and engines can still be used to offset the problems sailing ships had with adverse conditions. I think we'd really have to be on the last two litres of oil before that sort of thing was seriously looked at though, there have been a number of wind assisted schemes over the years which haven't caught on ( not counting actual sailing ships of course ).Regards,
Jo Meder
Boatbuilder and yacht design student turned software developer...
I'm going to buy a Prius and put a sail on it. That way I can be even more smug than every hybrid owner on the road.
"You call THAT a hybrid? Pfff."
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
So I think the Walker Wing Sail makes more sense than this para-sail system.
LoB
"Anyone who stands out in the middle of a road looks like roadkill to me." --Linus
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.
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.
I reserve the right to think for myself. Others' opinions are optional. Puppy on lap = typos...not illiteracy.
These kites are basically like spinnakers, moving the ship to leeward. This technology has been available since paleolithic times, when a dugout canoe could be outfitted with a rag on a couple of sticks. A major advance was made by the Arabs some 2000 years ago, with the invention of the Lateen rig, which is still just two sticks and a rag, but the rag forms a conic section, and pulls the boat towards the wind. Sailing on the prevailing winds certainly is useful, but these kites won't be anywhere near as energy-efficient as the large steel square-rigged freighters that were used to transport coal and other bulk goods around the beginning of the last century. They had a steam engine, but used it to power the winches to tack rig. That's the sort of thing we need; this kite retrofit is just a stopgap.
Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself. -- Mark Twain.