Wind Powered Freighters Return 261
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.'"
I wonder about the article photo (Score:5, Interesting)
Presumably that one-third savings is over... (Score:5, Interesting)
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.
While it is good for the environment... (Score:4, Interesting)
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.
The Flettner rotorship (Score:5, Interesting)
Good for cruise ships? (Score:2, Interesting)
Re:Welcome to the 80's (Score:5, Interesting)
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...
Another factor to consider (Score:3, Interesting)
Sailboats tend to need keels if they plan on sailing in any direction other than directly downwind.
I'm not just mentioning this as another thing to factor into the cost of retrofitting ships; there is also the consideration of the added draft the ship needs in port in order to avoid running aground.
I see this as a potential problem for using sails, since ports may need to further dredge their channels and inlets in order to allow larger sailing craft to load and unload their cargo. Will they still consider this cost-effective?
Jet Stream? (Score:2, Interesting)
Cool Stuff.
no, it wouldn't (Score:3, Interesting)
The keel is used as resistance. Because it has a large surface area, it resists the ship being pushed off line by the force of the wind. It's like squeezing a seed between your fingers. Your fingers are pushing up and down, but the seed shoots out sideways. This happens because your fingers keep the seed from going up or down.
This is needed because the wind may be blowing north/south and you need to go east/west. Just turning the sail and the rudder will only change the direction the ship goes so much, you'll never end up going crosswind, let alone upwind.
If you just turn the rudder, it won't change the direction the ship goes, just the direction it points.
I would think a long, slab-sided, deep draft ship might be able to use its own sides as a keel for this purpose. I don't know how effectively though.
The reason for the deeper draft is because the keel can't be removed on large ships. It protrudes down (see below) a long way, even when you're on engines.
The other thing a keel does (and this is perhaps more important on regular sailing ships) is keep the boat from heeling or flipping over when the wind fills the sails. The wind force wants to push the top of the boat over, so the keel is very heavy and sticks far down so that the boat won't tip over from that force. On a ship with a kite sail like this one, the attachment of the string can be put low enough (near the CG) that the boat will not try to flip over when the wind blows.
Re:While it is good for the environment... (Score:5, Interesting)
Well I was.. (Score:2, Interesting)
Big kite tech has come a long way (Score:3, Interesting)
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.
Re:These guys must have solved a major problem (Score:4, Interesting)
Re:Presumably that one-third savings is over... (Score:3, Interesting)
Wind like ocean currents is free. Airliners already try to catch tail winds when they can on the jetstream here in the US, and I guess its common for other countries as well. I believe that tankers already take advantage of currents as well.
What is interesting is that people used to be grateful to spend long periods (months?) of time to travel across oceans with an acceptable death/sickness rate of what about 30% to do international travel. Now, if an airline is delayed 30 minutes for an international flight that takes on order of hours we get pissed, and the risk of getting sick or dying is lower than driving to work.
Re:While it is good for the environment... (Score:2, Interesting)
It is unreasonable to expect a country to go from an agricultural subsitence society to a modern wonderland overnight. When a large portion of the population is living hand-to-mouth in squallor, some of these "slave labor" jobs probably seem like a decent alternative. As the economy and politics change, the working conditions will.
Re:don't forget piracy/war... (Score:5, Interesting)
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 (Score:5, Interesting)
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.. (Score:5, Interesting)
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.
Not what I would call sailing (Score:4, Interesting)
Re:These guys must have solved a major problem (Score:5, Interesting)
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.