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It's about time they did something like this to reduce fuel costs.

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Wouldn't that be a great symbol of the coming new age to see an oil tanker using a SkySail? :)

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Maybe I'm missing something but I fail to see how a little kite can achieve a 20% fuel savings on a 1,000+ ton freighter...

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@Kardax: From the SkySails website... "SkySails-System pulled the ship with up to 5 tons of power at force 5 winds, which when compared to the engine output represents a relief of more than 20%."

I'm a blogger, not an engineer Jim. ^_^ Someone else is going to have to do the math. That's the result they claim.

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That is great news - imagine the potential CO2 and particulate matter reductions that can be achieved! Congratulations to Skysails on their success! I hope to see news very soon of their receiving a huge purchase order from some big freight company :D

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Oh yeah, those photos are just awesome. I really like that aerial photo the best. That one photo from their website is 1920x1080 interlaced. It must have come from an HDTV recording. Man I'd love to see that video!

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Let's see if I can get the math correct: Assuming the ship was moving at 30mph, the ship's engine was delivering about 4,000 horsepower and the kite about 800.

30mph = 13.4 m/s
25 tons = 222,411 newtons
P=F*d/t = 222411 * 13.4 = 2,982,799W
2,983 kW ~= 4,000 horsepower.
Kite = 20% * 4000 = 800 hp.

Also, this assumes 100% propeller efficiency. You're actually looking at a slightly more powerful ship engine (kite output stays the same).

As for how the kite could deliver that much power, 5 tons means 62.5 pounds per square meter, which translates to 5.8 pounds per square foot. That doesn't sound unreasonable at all.

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30mph? We're talking cargo ships here. Half that figure is closer to typical cargo shipping speed.

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As a wind assist, Skysail kites offers several advantages over conventional sails. The kite reaches much higher altitudes where the winds are typically stronger. The kite can be semi-automated, using less crewmembers to operate. Only one mast is needed, reducing drag when wind is not available.

In certain wind conditions that would require a conventional sailing ship to zig-zag to tack into the wind, the kite on a skysail ship can do most of the zigzagging, making navagation easier.

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@ Phil L

"half that speed"

Cargo ships are much faster than most people think, they appear to be moving so slowly because of how big they are and the lack of reference points on the ocean. 30mph is near the top end, but about right for newer ships. With the longer ones being faster due to the "hull speed" phenomenon.

1kt =1.15 mph
"The most popular speed for the 1,500-2,500 teu ships is 18-21 knots, which applies to 70% of these ships. In the 2,500-4,000 teu range, 90% of the ships have a speed of 20-24 knots. 71% of the 4,000-6,000 teu ships have a speed of 23-25 knots. Finally, 80% of the ships that are larger than 6,000 teu have a speed of 24-26 knots. For the future ultra large container ships, a ship speed of 25-26 knots may be expected,"

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Come on now, ABG, do you really think that a kite twice as large will return twice the fuel savings? Is it really that linear?

Still, these kites being mostly automated is the real tech here. Without that, wouldn't be a success. And 600 square meter kites? That is MASSIVE!

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I haven't looked into the Sky-Sail website, so perhaps that's where some of this data came from. But the 4,000 HP engine calculation caught my eye because I clearly remember reading an article in Machine Design discussing an engine destined for use in a container ship. They were talking about 100,000 HP and the engine itself weighed over 2,000 tons. Unless the MV Beluga is a midget among seagoing ships, there is something wrong in the calculations.

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Thats pretty crazy that a kite can actually help so much . So why don't we just strap one of these onto every big tanker " oh i forgot its not that simple"

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