Kites

[daveculp]

Hmmm, The WSSRC apparently disagrees with you on this, from a physics POV. Also, are you suggesting that conventionally-rigged boats *aren't* tempted to abuse kinetics rules at night? ;-) Or that current rules--and Corinthian spirit--are not sufficient to stop either kinds of boats' breaking rules?

Dave

Hey, let's start a "pumping" thread. I got lots of ammo for one of these. Like, how about building a "self-pumping" rig, which uses wind power to pump the main and jib. You lose because of the energy taken to "auto-pump", but you gain from the pump. Physics says there'll be a net gain... Legal? Illegal? Cheating? You be the judge...

[Paul B]

Originally Posted by daveculp

..how about building a "self-pumping" rig, which uses wind power to pump the main and jib. You lose because of the energy taken to "auto-pump", but you gain from the pump. Physics says there'll be a net gain...

Really? Whose physics? Energy out exceeding energy in? Sound like you have designed the perpetual motion machine. And they said it couldn't be done...

[skinny boy]

So you ask for an opinion and then try to argue about it.

I don't care what WSSRC says. I don't care what you say. I think kites are stupid. If they were so great they would be on all the new boats. The reality is kites have not proved out to be anything other than a niche fad that will never find a home in true racing.

As I said it is another reason to push the kinetics rule, not that it is the ONLY reason. Don't ask for opinions if all you want to do is argue. I don't find it constructive to have to throw around huge generalizations like the above. However it seems that is what you were looking for so now you have so now you can go away.

[Paul B]

Originally Posted by skinny boy

I think kites are stupid. If they were so great they would be on all the new boats. The reality is kites have not proved out to be anything other than a niche fad that will never find a home in true racing.

Twenty years ago people said the same thing about Assymetric Spinnakers. Now all the new boats use them. In fact, "single luff" spinnakers were not allowed under most racing rules, just like kites today.

I have yet to see a boat flying a kite, and have yet to see any good race result based on someone using one. There seem to be some real challenges in using them in a tight bouy race. But times may change, development will probably continue, and maybe twenty years from now everyone will be using kites.

I wouldn't bet on it. I also would not have bet on all new Jboats having prods and A-Sails back when we were sailing the first J24s either.

Maybe the proponents of kites need to reel in the rhetoric a bit until they prove something in boat types that most of us are familiar with. I still use a Symmetrical Spinnaker and don't feel it is obsolete just yet.

In the dark of night in the middle of the ocean if you're going to cheat there is no one to stop you. You can wag your canting keel if it's fast enough or just start the engine.Sailing is not for cheaters and technology shouldn't be limited because poor excuse for a human being might violate the rules. Go Dave!

[cristofa]

If daveculp comes across a bit heavy at times, it's probably down to a passionate believe in a product that moves sailing evolution forward a notch, and a frustration at the the sailing world's extraordinary resistance to change.

I suspect that kites will not be used in normal racing to begin with simply because the 'rules' so successfully stifle progress. Kites need a lot of development before they can become an everday sea-level sail substitute, but they do have substantial advantages and, in due course, someone will produce a fully sorted rig which will probably be used initially for ocean passage-making. Then word will get around ...

I don't race sailing boats, and don't know what the 'kinetics rule' is, but in a real kite powered boat, when you 'sweep' the kite on a broad reach in a stiff breeze, the speed you get is just enormous grin ear to ear FUN!

atb ... Christopher

[cristofa]

Now that IS interesting!

I have just read in our local paper that ... "Dom Mee will officially announce today that it is his intention to traverse the North Atlantic from St Johns, Newfoundland, Canada using the Worlds first ocean going Kite Boat. He is expected to arrive into Exmouth, Devon, anywhere between thirty five and seventy five days later." You can read all about it on his website:-

http://www.dommee.co.uk/pgs/news/news-room.html

And who do you think is supplying the kites?!

In politics and business you are obliged to declare an interest ... on internet forums I guess it's just down to plain good manners. But I now understand why you were so keen to pick my brains on my ocean-going kite boat, Dave.

I wish Dom Mee all the luck in the world, and believe he might need it. I thought that at 22' 3", my boat was decidedly on the small side ... I can't begin to imagine why Mee would choose to attempt this trip in a craft measuring only 14'! I am also intrigued how he will fly and control a kite from his boat, though, as it seems to be lacking features that I would have thought were important. Oh well! Pity he doesn't have some video clips (or even photos, come to that) of his craft in action.

For those who are curious, I have found some pictures of my boat ... unfortunately, the only ones of the boat under 'sail' out in the bay were taken by someone else, and I can't get hold of him.

pics 1 and 2 show fitting out ... I used the plywood cover during trials pending the arrival of a Lexan-windowed cabin top. pic 3 shows the boat under way in the harbour ... I was sitting on the floor inside flying the kite through its built-in control system. (it's a pity the guy standing up didn't stand in the middle and ship the boat. pic 4 is on the quayside after a trip in the bay ... 3 an 4 show the small, 2.5sqm kite which I used to get the hang of the controls.

atb ... Christopher

[nero]

thanks for posting the photos.

Kite has a different shape than I imagined.

Did you have a big bow wave with that round bow? or does the kite keep the bow up?

[daveculp]

Originally Posted by cristofa

Now that IS interesting!
http://www.dommee.co.uk/pgs/news/news-room.html

And who do you think is supplying the kites?!

Try here: http://www.kiteship.com

Pity he doesn't have some video clips (or even photos, come to that) of his craft in action.

There will be. The boat was only launched this week--they've been practicing with an ordinary dinghy, prior to that. There wil be photos in flight, and I'm told, videos.

Thanks for the photos, Chrostopher!

Dave

[daveculp]

Originally Posted by Paul B

Really? Whose physics? Energy out exceeding energy in? Sound like you have designed the perpetual motion machine. And they said it couldn't be done...

That's my point--pumping is NOT the same as "air rowing." Sure, you can row a boat along with its sail, but pumping is not the same--there's far more energy coming in than going out. No it's not perpetual motion, it's using hysteresis effects to--very temporarily--gain a great deal more lift from the sail. Insects use this all the time or they couldn't fly at all.

And yes, "working" the kite is also similar to pumping, except that almost no power is input by the pilot--but 3-10 times the kite's "static" power is taken out.

Probably too good an idea... Better ban it.

Dave

[cristofa]

Originally Posted by nero

Did you have a big bow wave with that round bow? or does the kite keep the bow up?

I guessed someone might pose that question, but I don't have pics of the hullform below those near-vertical topsides to show the reasoning behind the shape. The hull was very light and, with the lift from the kite, it was easy to plane. To provide lift and make the boat as sea-kindly as poss (to reduce the fatiguing effects of prolonged slamming), the bow below the topsides is quite deep and rounded. It worked pretty well and that blunt bow, in fact, hardly got wet as the spray shot off the chine.

I look forward to seeing pictures of Dom Mee's boat in action ... what size kites will he be flying?

atb ... Christopher

[CT 249]

"If daveculp comes across a bit heavy at times, it's probably down to a passionate believe in a product that moves sailing evolution forward a notch, and a frustration at the the sailing world's extraordinary resistance to change."

The first sounds fine, but is the sailing world really THAT resistant to change?

I suppose it depends where you come from, and how reasonable you think it is to throw away (from the racing scene at least) perfectly usable boats and gear. About every ten years or less we see an enormous change in boats. What a vast waste (in many ways) of money, enthusiasm and scarce resources just to go a bit faster!

In the last 50 years there have been several enormous changes. The "state of the art" 40 footer in 1955 was timber, long keeled, with a heavy slender hull and stiff rig. By 1965, it was masthead rigged, fin keeled and fibreglass like the Cal 40. By 1975, it was a beamier, higher IOR type like a Peterson. '79, and the state of the art 40 footer was something like a lightish, fractional centreboarder. Centreboards came and went in just two years in the IOR.....not much resistance to change there. Another 10 years and it was a Beneteau type or an early Sportsboat, maybe a water-ballasted Open type. By 1999, the "state of the art" was a canting keeler or Farr 40 OD. Speed is up by 20% or so, which isn't bad considering these boats are inherently limited by waterline length most of the time. How much change do you want??

Same in skiffs and dinghies. State of the art 1950, an Uffa Fox style International 14 - planked, no trap, little buoyancy. State of the art 1960, 505. State of the art 1970, a Farr plywood 18' skiff - much lighter, much more rig, three men all on trapeze. State of the art 1980 - a carbon fibre skiff with racks. State of the art 1990 - skiff with flex-tip mast, assymetric spinnaker. State of the art 2000 - maybe a foiler.

Have you sailed a replica 18' skiff and a modern skiff? Have a go and see how much change there HAS been.

Over the same time the multis have gone from Pivers and Shearwaters to ORMA 60s and carbon A Class. Foilers have gone from Williwaw to Hydroptere. Have you sailed a Piver 25 and then hopped on a modern carbon 25 foot multi? The difference is enormous. How could such an enormous advance come if the sailing scene hated change so much?

Exactly how much change do you want? How much money do you want people to throw away just to go a bit faster?

[water addict]

imagine trying to untangle the kites at a crowded mark rounding!

[CT 249]

Note to all...sorry I got a bit strident, and I'm not attacking kites or development per se. Just not sure that the sailing world is so anti development.

[CT 249]

Originally Posted by daveculp

I think you are right, Fred. A sail which is self-supporting and, as you say, "just waiting for some push" is surely the best way to deal with 0-2 on conventional boats. Chris 249 seems to agree with you as well, if I'm not putting words in his mouth

I'd love to build a "wind finder" kite for these conditions; rigidly inflated with helium, flying 100m or so above the waves, sitting quietly above the slop and surface turbulence.

As Christofa says, a kite such as this is rarely becalmed and will keep the boat moving in wind you cannot feel on the surface. A couple of questions:

Is it the consensus that a kite like this should/should not be "legal" for sailboat racing? Keep in mind that helium lift cannot develop forward drive, so isn't "cheating", at least according to the rules of physics (it's been ruled legal for speedsailing by WSSRC, for instance), but that such a kite will "obsolete" many boats.

How would readers feel about the cost and complexity of such a solution? (cost maybe $100-200/sq meter; complexity involves wrestling helium cylinders into/off the boat (or building them in), also wrestling with a big inflated kite on the foredeck, perhaps in a rising wind. We'd include some "trick" launch/recovery equipment/methods, but the basic facts remain--it's big, it's on the foredeck, and you've got to muzzle it.

This sounds like a potential solution for cross-ocean "open" type racing--and for "painless" cruising with smaller kites. Will cruisers pay this kind of price and will racers put up with the hassles?

Yeah, I'm doing market research here. Your opinion counts. Thanks for all replies,

Dave Culp
KiteShip

The idea sounds cool in some ways. I suppose you could have a massive "panic button" patch that would be torn open for instant deflation when you got a 3 am southerly buster half-way across the Tasman Sea. The worst thing I know to handle on a foredeck is a windsurfer rig (when rigging at anchor while cruising) and this would probably be better which would make it a thorough biatch, but handleable in the end.

But I remain waaaaay too worried about long lines to use one in the harbour on a regular basis. And there's no way I want to have to fart around with gas while sailing. Maybe it should be "legal" for sailboat racing but not for most PHRF and IRC ("normal yacht") racing.

On the other hand, I suppose if you had a kite that developed lift, you could have larger diameter lines going to more points, which may dispel one of my fears about kites on boats. You could also perhaps keep it lower - OK you'd go a bit slower but why is sailing so horrible you have to hurry to the finish? :-)

Most of my cruising is done with kids and it's normally just loafing along.