get home kite sail

[kelp]

Not sure if this the right forum. Tom Colvin won't let me install a mast and get home sail on a steel 34' steel dory I am building.Stability problems. I thought kite sails might be a good idea, but soon discovered they are hard to control, so what about a tethered balloon? It could store in a canister with the appropriate inflation tank and be deployed when the engine fails. Could a balloon generate enough thrust to have steerage and maybe make one or two knots? I have no idea about whwre to begin with the calculations. I realize that even if it makes sense (which it probably doesn't) it would take an enormous amount of effort to develop. My boat will never see it. But it's fun to think about. OK you can laugh without hurting my feelings. Any thoughts on this?

[Guillermo]

I understand low aspect ratio kites like those of kiteship (http://www.kiteship.com/) are easy to fly and stable.
A balloon inflated with lighter than air gas could fly a series of flags or ribbons along the towing line, thus increasing drag..... just an idea. But the problem could come when retrieving it.
Perhaps you could use an inflatable kite as alternative...
http://en.wikipedia.org/wiki/LEI_kite

Cheers.

[Fanie]

Or maybe think more than one kite. Fly the first one up, then the second on the same line and so on. If you have enough kites on the same line it would be the same as one big one. I haven't thought about the control though.

Kites can fly to wind as well as any sail. My one friend has one of these two handle kites. You can fly it anywhere you want, even almost directly overhead. Imo if you can get something like that in an over size it will work very well.

Just think how nice it would be if you can get rid of the masts and sails and just sail with a kite...

[apex1]

As mentioned the control is the point. The commercial installations (skysails) like this one:
http://news.bbc.co.uk/2/hi/europe/7205217.stm
http://www.skysails.info/
use a computer hanging in a gondola under the kite for the line control. That is a very sophisticated and a very expensive gear.
Kiteship is a bit unmature compared to that.
Any uncontrolled system (you naturally cannot manually control like the smaller kites used for surfing), will pull you the way the kite (wind) likes. Thats not the way to go.
We will have to wait until these skysail systems are getting widely used in the commercial world to be affordable for yachts.
Since 10 or 12 years I am playing with the same idea to install such system on a passagemaking motorcruiser as a coming home backup. Prices are already down to around 250.000€ for a small ship, but that still is ten times the cost of a simple rig.

Regards
Richard

[Fanie]

No we don't wait untill someone else does it 4 5 c. Skysails have their ideas, I have other ideas.

I'm sure you must have seen these four line kites the guys play with and how well they control. So if you have a kite with four control lines, ok. Then on each line there is a series of different size stops in each line.

The higher stops are larger than the lower ones, so if you have one kite up and it flies, you clip kite no 2 on. The kite slides up the four lines and over the first smaller stops but get stopped at it's own stops.

The wind always pushes the kite up, so it will stay in place but it could also be possible to make it so it can clip in it's own place and stay there. The distance between the kites are preset by the distance the stoppers sit from one another.

Now if you pull any one line both these kites are going to do exactly the same, so you have control over them.

In the same way you can now add more kites, giving more lift and sail power and as controllable as when you had only one.

The sail control should also not be such a big train smash either. If the kites are up and flying and if they are rather large then you are going to need a fairly strong control mechanism. This can be achieved by using three electrical motors that control a mechnism to function similar to the hand controls you get on these small kites.

The only difference in me playing with these things as to sky sails is they have money. I don't so I can't get my projects done.

The wife says if I live to be 500 years old I won't get them all done... which is good, right ?

[apex1]

Right Fanie, we all should have projects for say at least the next 100 years.
The kite control is not as easy as you would like it to be (does not matter one or ten). To provide enough pulling power per m² the skysails are elecronically moved to fly a "(8)" figure in the sky. This brings the aerodynamic profile of the kite into the play and enhances the power by about three times over a stationary kite, this cannot be cotrolled by winches from deck. It is as impossible to pull the two steering lines on a conventional kite (or ten of them) in a fast responding manner to get a proper pull towards your heading, if using winches on deck.
If we like it or not, the skysails way is the right one and we just have to wait until the fishing fleets step into that (or competitors), to get it much cheaper.
I´m shure it will not cost more within the next 5 years than a good conventional rig.
Regards
Richard

[Fanie]

Hi Richard,

I'm sorry but I disagree with you once more.

One of the biggest handycaps we allow ourselves is to think within our own reference boxes.

I have no illusions about the force these sails can make, and especially at a certain height there's even more wind. Which is of course ideal because down on the water we prefer wind still, it's more pleasurable and you don't have to shout when you order another drink :D

If you have four lines to control the kite, then surely the pull in all four are about the same. So if we pair them two left and two right then it works out.

If you consider the left two lines, if they are on a lever that hinges on it's center then you need little force to disturb the ballance, hence the kite will react. Same with the two right lines. If keeping them moving makes such a big difference.

Imo, if one can only replace the mast and sails with an easy to use kite system it would be great already. Only problem I see is if you have very low wind that cannot sustain the kite, then you will gain having a sail, you can still move a bit in low winds.

Remember the only reason the kites control are considered complicated is because nobody has made the easy to use one yet. There was a time it was impossible to sail any direction other than downwind. Today you are a retard if you think like that.

In a while kites may become the common standard and you'd be a retard if you use a mast and sail. Who knows. Saying wait till someone else has done it first, well, that's what they all say looking at you :D

[apex1]

I do´nt mind if one disagrees here. Nevertheless my statement is right, I used controlled powerkites in the past. (not on boats naturally, at the beach)
Yes the forces are not too high to steer the kite (therefore the electronic control box can operate the skysail), but the pulling force has to be directly lead to the boat and divided from the control lines. Now we have the steering lines left, will you hold them in your hands to operate the boat? All day? Turning eight´s in the air? We are not talking about a dinghy or surfboard, are we?
If you visit the website I linked to, youll get a deeper insight.

"Imo, if one can only replace the mast and sails with an easy to use kite system it would be great already."

I would be happy too, but that is what we are missing, there is no such easy to use kite!
And if the wind is below 3 Bft. there is not even a very sophisticated kite, just a gentle rollin sampan where we can enjoy another drink, before the trouble starts.

Regards
Richard

[Fanie]

Here is a simple way of controling the kite, as I said earlier motorised.

The angle of the swivel arms will control the kite's height, while one arm moving with the motor pushing it in or out should give you a kite flying left and right, possibly already doing a figure 8.

Holding a kite with your hand on a boat is not an option. You'll get plucked off your lazy boy and flewed all over the ocean and I bet you'd learn some kite skills real quick then.

One day when I get time I may build a model to fly one of these sports kites. Can't be too hard to make. If the motor is controlled with a wind vein or even a compass to determine where the kite is wrt a preset diection, why not.

[apex1]

Fanie how do you control a kite that is 200 meter above you? By electronics, nothing else is sensible. The windvane mentioned can determine the surface wind only. And how complicated must a system be if you involve a compass (in the kite), without electronics? How do you do the steering with the apparatus shown? Where does the input signal come from? If it would be easy to compensate these electronic controls, "Beluga Shipping" would have done it in the past five years, since they are involved in that project. Maybe "skysails" would´nt, but Beluga has only a commercial reason and paid for the development.

I have understood your plan right from the first moment, for that reason I said its not the way to go.
And naturally I know the power of a aerodynamic kite, a bit over 1m² lifts a man easily. I have some kite skills.
Regards
Richard

[mydauphin]

I am interest in this idea. If anybody can get it to work it sure will be worth money to them.

[apex1]

Mydauphin, it is working and it makes money since several years now. Look at the links above.
Regards
Richard

[ancient kayaker]

I think kites are interesting and have real potential to reduce fuel and/or provide a lot of fun. However, there are cost issues with the high-tech ones, control issues otherwise, and since this boat clearly has no keel a kite will only haul it on a downwind course with maybe3 points either side.

The issue is, Kelp just wants to get home if the engine fails, and doesn't mind if it's slow. I would suggest a small outboard.

[BeauVrolyk]

Have a look at: http://www.youtube.com/watch?v=qnACybMhPs4&feature=PlayList&p=A1C0A6FABAB9FAC2&playnext=1&playnext_from=PL&index=6

A friend of mine built a kite powered cat and it hit 35 knots numerous times. There weren't control problems, provided you know how to fly the thing, even here in San Francisco in 25K +++

[Fanie]

I saw that. So no one else shoud try that, and they are so environmentally concerned that he took a bat to the fish he cought. I also didn't know sailboats were so unsafe...

[Guillermo]

Fanie,
From my point of view, kite control problems are probably not very easy to solve for a 'fit and forget' system. I have been following closely the Skysails concept since several years now and I have organized three presentations of the system to commecial fishing vessels owners and engineers here in Galicia, unluckily with no success up till now.

Skysails have spent more than 12 million euros through a decade in the developing of the system and they are yet at the first commercial tests stage. On his side, Kiteship has run out of business after many years of hard work, in spite of their knowledge and efforts.

To develope a fully reliable, simple and affordable system has proved to be not such an easy task to achieve. But keep on trying. :)

Best.

[Fanie]

He he... I saw that guy kayak kite sailing on youtube. Each time the wind changes, that canoe goes right after it.
Sailing like that can get you up on drunken sailing charges... :D

Here's my opinion on the kite sailing.

All these guys have only one thing in mind and that is to make money. Since it is a 'new' idea the race is on to be ahead of any one else out there, and they want to do it today and make the trillions overnight.

I see it here with guys developing other things. They don't do research, certainly not enough and expect to be successfull and they all just want to become rich very quickly. I guess what I'm saying is they see the money and not the product. Keep in mind everyone is an expert on everything, and certainly the guy with more money knows even more.

It's a bit like the guy who has the biggest dcik but has no real use for it :rolleyes:

I have one customer that is doing such a development (not on sails) and each time he gets here and want some 'magical electronic' thing that is going to solve his problems, I realise there are too many unknowns that he has not investigated. When I point them out, he doesn't know, he hasn't done or he hasn't investigated. This guy has no chemical knowledge, yet he is putting together something chemical. Do research and gain knowledge first... Nah, will take too long...

Long time to make a point.

There were millions of 'land' kites built to today, if I look at he ease and the performance, just as an example, what my friend's kite can do. then I ask myself what are these other guys trying to do...

Start small and get the basic principles in order first then proceed to go bigger. To me it's like they want to build tankers before they even try a smaller boat to make sure it works properly only brcause there's money in it.

The key to successfully put kites up there is going to be in the control of it, and you have to do it on a moderate scale first.

The guy with his kayak certainly didn't hink it through properly, he just wanted to be pulled around for fun. There are other canoes on youtube being pulled by kites, but those were just for fun.

Imo it is more than possible to make a proper controller for a kite. I certainly won't like the tank monstrosity on my boat and the continuous hands on steering is out, maybe if you want to begin racing already although I don't know who against.

I want to point out what I said before. You cannot handle a 20 sq meter kite properly let alone a 200 sq meter kite, then go down to a managable size first. Doesn't matter if it is too small, but get the basics right first then find ways to increase the kite area. The guys doesn't have a single kite up that works properly that I have seen, yet the figure 8 aerobics it must be able to do is already expected.

So, bugger the wings, just go fly off the cliff...

[apex1]

What does it mean you cannot handle a 200m² kite? Skysails does it, and very successful. They do not play with unmature ideas, they did some 12 years of proper development before the first system was sold.
Money over night looks different.
Regards
Richard

[Guillermo]

I certainly back up what Richard is saying. Skysails has painfully gone all the way up from a humble beach kite (as Fanie demands) to the commercial stage in full scale for merchant ships, risking a huge amount of money in the process for a decade or more. Presently they are flying kites developing over 300 HP under full control for days on end, and their plans are to come up soon to powers in the range of thousands of HP.
Your criticisms are not well funded, Fanie.

Cheers.

[Fanie]

Your criticisms are not well funded, Fanie.

Probably not. So why aren't we seeing kites for other boats as well ?

[Guillermo]

I think the answer is easy: precisely because to develope an efficient, easy to deploy and retrieve, fit and forget system has proved to be very very expensive.

Cheers.

[Fanie]

If they are going to be too expensive why do we bother then :D

[apex1]

That was answered too Fanie. I think I made it clear, that we just need some patience. These systems will become cheaper in the near future.

[Fanie]

Imo it's already written of by most as too expensive, too complicaed, too uncontrollable and too long to wait for.

[apex1]

Imo it's already written of by most as too expensive, too complicaed, too uncontrollable and too long to wait for.

By most does´nt mean by experts. It is neither complicated, nor uncontrollable, not too expensive (not a single one shipping company in the world would buy it if it was), and it is available off the shelve. (actually they started production recently so, one cannot assume it will get cheaper within the first days of production)

It has only one serious disadvantage:
It does not fit your imagination of such a system! sorry..............but this may convince you!?:
http://s2.streamingfarm.tv/streamingfarm/skysails/pk_michael_a/20080627_Skysails_PK_480x270_1000KBit.wmv

As Guillermo does, I follow this development since almost 12 years now, and if we tell you it works, you may believe that we know what we are talking about. And it is a fact that wealthy shipping companies like "Beluga Shipping", "Oltmann" "Wessels" and the "Zeppelin" group invested a serious amount of money in that technology, there are no day dreamers amongst them.

If your launch is not within the next year, be patient, it will come down to be affordable (at least for a boat range above 20 m) And please mates do´nt argue about this "upper class" restriction. Bear in mind that almost all of the safety features in our cars have been brought on the market in the "Mercedes S class" top models at the first time (a car of the same value as a house!), today all of them are standard features in every "rolling ashtray".

Regards
Richard

[brian eiland]

Have a look at these YouTube presentations posted over on this other subject thread:

http://www.boatdesign.net/forums/boat-design/new-age-trawler-motorsailer-kite-assisted-poweryacht-20319-12.html#post273209

[brian eiland]

http://www.boatdesign.net/forums/sailboats/kite-dinghy-12279.html

[brian eiland]

..from another subject thread

The kite you say it is similar to looks like an old style C-kite. These kites have a limited ability to depower through the action of easing the bar. This means you will need to be VERY CAREFUL with how you fly it as you will not be able to instantaneously depower. Instead you will only be able to depower based on where the kite is in the wind window.

I would recommend the use of the newer style bow kite which, through the use of bridles on the leading edge, allows the rider to adjust the angle of attack instantaneously and so effect much more immediate depower. The bow kites are also generally substantially easier to relaunch.

I don't mean to dump on your selected equipment but you should be aware that there are big differences between the various kites out there and some will be far more suitable than others for the task of pulling boats.

Good luck with your experiments but read up on kite safety before you do anything with the 20m kite.

[Fanie]

Mmmm Brian, I can see a LOT of headings in the newspapers reporting mysterious disappeances of boaters.... and reports of 'discovered' boat captains found surfing off the coast of some foreign country... Unshaven of course.

Wrt kiting this video was a real inspiration for me !!
http://www.youtube.com/watch?v=LtY4bcI_fM0

[brian eiland]

Wrt kiting this video was a real inspiration for me !!
http://www.youtube.com/watch?v=LtY4bcI_fM0

Thanks Fanie, that was inspirational :!: