ISAF vs KITE Sailing

[usa2]

how do you go upwind without a keel...even if your just flying a kite?

[daveculp]

Originally Posted by CT 249

Dave re "In actual fact, kite sailed boats are faster, stabler and safer than any masted sail boat (go to my web site for the reasons why, if you like)"

Cogito? 18s? speed boards? G Class?????????????

You're a hard guy to please, Chris! Maybe if I'd just said "faster than YOUR boat"? ;-)

But, yes, existing OutLeaders can increase the average speed of the G-cats; they are a major target for us, in fact. Speed boards--Absolutely. Every year kite boards get 5-10% faster, windsurfers gain hundredths of a knot. Kites can survive, in larger sizes, in bigger winds than windsurf boards can. The performance curves will intersect soon. I'll even make a prediction on this one--within 3 years, 4 at the outside.

Cogito? That's a very hard nut to crack, as you know. Still, the answer remains yes--not with any existing kites, but if I had the budget and engineers--and the impetus, which I do not--the underlying physics still favor kites even over wingsails (they'll be "hard shell" kites; wingsails themselves. The hull will be a single ama--likely with an inflatable pod for stability at rest. All-up weight less than half of Cogito's--no rig weight and only one hull; and wetted surface--virtually all the time--will be less than Cogito's minimum, again due to the single hull and lighter weight. Yeah, Cogito can/will fall to kites, too). You can argue tactics if you like, but if the boatspeed is 10-20% faster, tactics don't matter in the long run.

Kites' advantages aren't marketing hype. They are real, and right in front of you. The salient questions are 1) how quickly will practical application equal theory, and 2) How tough is the political acceptance going to be. 1) will happen more or less quickly depending on 2) but 1) WILL happen, regardless.

Cheers,

Dave

[D'ARTOIS]

I was on your website and saw several boats equipped with your sails - I see it as a sail rather then a kite although it is a extra-proportional kite.
What I could not find is how you control this kite, till which volume you can fly one and how you launch it. Finally, where are they most efficient, under which weatherconditions, I mean?

[yipster]

http://www.twistandturn.co.uk/orBars.htm
when they came into fashion i did some very high jumps on land hanging on a bar that only had 2 strings attached to a kite that blew itself up to a foil having holes in front, you can direct them and in stacked formation you'll be really flying! never sailed them

[D'ARTOIS]

Scary......No, I saw on this Kite-site a 60 or 65 footer (AAPT) with an enormous
kite making some substantial speed. That tri that lost his mast and came back by way of this kite-configuration did not bad at all and made sometimes speed it had done under sail also - so it is a very serious thing to consider, on plain open water with no ships in the neighbourhood, otherwise it will be Chinese kiting......

[dionysis]

It's usually the case that rules forbidding something are introduced to protect the status quo. It may be as simple as that.

AFAIK, kite driven sailing boats need to be actively controlled. So if you are cruising along and want to take a nap, do you have to bring the kite down? Launching a large enough kite to drive a cruiser lookes difficult too.

[daveculp]

Hi,

The big kite aboard AAPT (420 sq meters) is ours. We spent 2 years in secrecy developing this kite, for the America's Cup race in 2003. It was legal, but not used, in that race (the syndicate which hired us was eliminated). The kite is patent pending.

Yes, it is fully controlled, very much like a spinnaker sail. It is quite easy to launch, fly and recover--it is the first kite ever to be so. At 420 sq meters we are not only 10 times as large as any other self-launched kite, it is actually a world record for largest kite ever to fly from a floating structure (the outright largest kite ever built is about 900 sq meters--we are doing the engineering now for a 1000 meter OutLeader for one of our customers)

Our company, KiteShip, is manufacturing and marketing these kites for the replacement of spinnakers; they are proven faster (stronger wind up higher) and safer (no heeling, no pressing the bows down, no broaching) than any spinnaker.

Our customers (some 4-5 dozen worldwide at this time) are mainly racers, but include cruisers, single-handers and power boats.

See our web site for more information; http://www.kiteship.com (including videos of the launch and douse); and also our discussion group for additional drawings, photos of launches, deckplans and discussion with present owners and users: http://groups.yahoo.com/group/outleader

Cheers,

Dave Culp
KiteShip

[daveculp]

Originally Posted by usa2

how do you go upwind without a keel...even if your just flying a kite?

OutLeader kites are spinnaker replacement kites; being a specialized sail they will sail on a reach or below, not upwind. There are many upwind kites, including those made by us, none have successfully been built at large sizes and attached to large boats (though kites have been pulling boats upwind since at least 1827--yep, 178 years). There will be large upwind kites on boats within the next 3-5 years; many are working on this. They will not, however, be inexpensive. OutLeaders cost about the same as premium spinnakers--large upwind kites, which can replace the whole rig, will cost far more.

A daggerboard is required, a weighted keel is not--though most boats already have them--in order to sail any course other then dead downwind. Though OutLeaders are spinnakers, we do use the boat's keel (or centerboard) to develop sideforce--just as do any other sails or spinnakers.

Dave

[Paul B]

Originally Posted by daveculp

Hi,
Our company, KiteShip, is manufacturing and marketing these kites for the replacement of spinnakers; they are proven faster (stronger wind up higher) and safer (no heeling, no pressing the bows down, no broaching) than any spinnaker.

Our customers (some 4-5 dozen worldwide at this time) are mainly racers, but include cruisers, single-handers and power boats.

Cheers,

Dave Culp
KiteShip

Hello Dave,

Do your 48 to 60 customers worldwide include only yachts, or does that also include boards, iceboats, etc? You say most are racers. What type of races do they usually participate in?

Can you provide any results where a kite was used in a major dinghy or yacht race and prevailed? Let's not include boardsailing, only dinghies and yachts. Did your ACC client ever use your product in any of the LVC RRs? Was there ever a two boat test race within the team, a complete race not only straight-line testing, where the kite equipped boat beat the other boat around an ACC course?

Quoted from the February 2005 Seahorse Magazine report by Rob Mundle (page 20) regarding the AAPT Hobart config, quoting Langman, "We tested it (the kite sail) with no mainsail set and compared it with a conventional A-sail, and the A-sail was faster."

Why would they be testing without a mainsail? Even the photos in Seahorse show the boat sailing without a main. Is this a requirement of your kite?

Why would he say this if it is proven that the kite is faster?

The large congrats on your site seems strange considering they didn't use your product in the race. If someone only looked at the headline and didn't read the article they might be led to believe the congrats were due to your product. Why no congrats article for the Nicorette first to finish? They used a kite just as much in the race as AAPT did.

[usa2]

would you mind explaining how these upwind kites work? To me, the concept seems a bit weird, since the kite is being blown one way and you want your boat to go the other way. thanks-
usa2

[Skippy]

As for being blown the wrong way, the sail does that too. They're both at an angle wrt the boat's heading, so both of them have an athwartship component to their driving force. The keel resists that part, which leaves the forward component to drive the boat through the water. The main difference is that with the kite, you don't need the heavy keel or big wide multihull to resist the heeling moment that you get from a sail.

So ultimately, the kite is no different from a sail. It gets lift from the wind by controlling its angle of attack just like a sail does, so it's being blown in essentially the same direction as the sail. The windspeed is higher at the kite's elevation and it takes up more space. But the main difference is that the kite is tied to a free line, which has several effects:
1) The kite pulls directly along the line holding it, so as long as it's in the air, its force will be partially upward.
2) You can attach the line to the hull at a point where it won't exert any heeling moment, or where it will help counteract the overall moment exerted by the other forces acting on the boat (gravity, bouyancy, lateral resistance, and drag).
3) The direction of the kite's force doesn't change when the boat heels.
4) When the boat heels, the kite may exert a small rotational moment that helps stabilize the boat.
With no heeling moment, the driving force can theoretically be enormously greater, plus the upward component reduces the boat's displacement.


[Edited to make more sense]

[daveculp]

Originally Posted by Paul B

Hello Dave,

Do your 48 to 60 customers worldwide include only yachts, or does that also include boards, iceboats, etc? You say most are racers. What type of races do they usually participate in?

Cool! A doubter. We love you guys; keeps us honest! I'll try to answer each of your questions;

We limit the minimum size of our OutLeader kites to 35 sq meters, for several reasons. We currently fly from a yacht's existing winches, and boats smaller than aobut 22' don't have these. Also, a smaller kite requires smaller, lighter lines. W use 1/8" lines for between 35 and 70 meters which we believe are practically the smallest one can handle with gloves on. Smaller kites would need smaller lines which are dangerous to your hands. Kitesurfers get around this by never touching their lines--they always launch assisted, with the lines at full length.

Most of our currently installed kites are aboard boats that race--Corsair Trimarans, several large multis (Afterburner on the West Coast, Alacrity on the East; both 50'ers, a cat and a tri); many of our kites are aboard one-off multis, in the US, Britain and Australia. Boats from 33-48'. We are constantly pushing for races for our customers to participate in. As with most new technology, organizers are wary of us; we've been banned from some races, embraced by others, and hotly talked about by almost all.

Can you provide any results where a kite was used in a major dinghy or yacht race and prevailed? Let's not include boardsailing, only dinghies and yachts. Did your ACC client ever use your product in any of the LVC RRs? Was there ever a two boat test race within the team, a complete race not only straight-line testing, where the kite equipped boat beat the other boat around an ACC course?

Nope. We were scratched late from the Sydney Hobart (which went to windward this year), there was too little wind in the (NZ) Coastal Classic; we are right now in the 'Round North Island race, which is also going (gone?) light, it seems. We were barred from last year's Chicago Mac and also Bayview Mac, though we had boats entered in both (both went light, so the ban was moot) We are currently working on the TransPac (both the transpac and Chi-Mac are Americap races). Newly allowed multihulls in the Pacific Cup may carry kites (we're working on monos for this race, too). Americap requires polars and wind tunnel data--they say--on order to build a VPP for rating OutLeaders. We are not able to fund this work ourselves. Any ORCA race is encouraged to carry kites, but we just got this ruling, so none have, to date.NorCal PHRF is allowing kites on any boat they rate. We were closed out at last year's Double-handed Farallones race (normally a windward/leeward raced, it was a reach/reach last year), but we have 3 and possibly 4 kite boats entered this April. Please keep in mind that we were under a contractual secrecy agreement until April of 2003; we sold a grand total of 4 kites in 2003; all the remainder in 2004. It's still early days.

Quoted from the February 2005 Seahorse Magazine report by Rob Mundle (page 20) regarding the AAPT Hobart config, quoting Langman, "We tested it (the kite sail) with no mainsail set and compared it with a conventional A-sail, and the A-sail was faster."

Accurate statement. On our front page, paragraph 2 of our lead article, we admitted we blew the engineering on this kite, could not power it up on first flight. Also where we worked with AAPT's sailmaker. We re-engineered the kite and PAID THEIR SAILMAKER to make the necessary alterations. We still offer our comprehensive money-back performance guarantee--the only one in the business. FWIW, AAPT still owns their kite...

Why would they be testing without a mainsail? Even the photos in Seahorse show the boat sailing without a main. Is this a requirement of your kite?

Nope. It has been very widely documented that we train new users of our kites without any other sails flying. The crew needs to learn what the kite will, and will not do without interference from other sails, then learn to fly--and launch--behind the main. All of the publicity shots of AAPT were taken during the first--the very first--flight of the giant kite on that boat. FWIW, watch this space; this kite is going to be given a Guinness world record for largest kite ever to pull a boat.

Why would he say this if it is proven that the kite is faster?

I think I covered this above. Have you checked out our discussion list, at http://groups.yahoo.com/group/outleader? Have a look at the customer testimonials there, where folks tell us they've never sailed so fast, never felt so "on rails" sailing offwind, etc? Did you read about the older half-tonner in Perth we had 3-sail reaching with our kite--at 11 kts of boat speed (fair for a non-planing 40'er, eh?) Have a look at the photos of the J24 pulling a "tugboat" wake in Sydney haarbor last December, doing 9+ kts: http://www.pacificsailingschool.com....bums/KiteShip/ Did you also read the bit about AAPT being able to pump out all water ballast when flying the kite? This makes the 11-ton boat 3 tons lighter. D'you suppose that may have some effect on her ability to plane out at speed?

The large congrats on your site seems strange considering they didn't use your product in the race. If someone only looked at the headline and didn't read the article they might be led to believe the congrats were due to your product. Why no congrats article for the Nicorette first to finish? They used a kite just as much in the race as AAPT did.

AAPT are our customers, they spent a large amount of money to purchase our kite and to fly our people into Sydney for training; Nicorette are our competitors; how would you have put it, in our place?

I'm pulling your leg a little bit here, Paul. Your profile says you're in California. Why don't you get in touch with me, and I'll arrange for you to take a test sail? You can then come back here and tell of your own first-hand impressions, good or bad. I don't think I can offer more than that--the industry's only performance-based guarantee, and an outright offer to bring doubter aboard and then write about it.

What do you say?

Dave Culp
KiteShip

[daveculp]

Originally Posted by Skippy

As for being blown the wrong way, the sail does that too. They're both at an angle wrt the boat's heading, so both of them have an athwartship component to their driving force. The keel resists that part, which leaves the forward component to drive the boat through the water. The main difference is that with the kite, you don't need the heavy keel or big wide multihull to resist the heeling moment that you get from a sail.

So ultimately, the kite is no different from a sail. It gets lift from the wind by controlling its angle of attack just like a sail does, so it's being blown in essentially the same direction as the sail. The windspeed is higher at the kite's elevation and it takes up more space. But the main difference is that the kite is tied to a free line, which has several effects:
1) The kite pulls directly along the line holding it, so as long as it's in the air, its force will be partially upward.
2) You can attach the line to the hull at a point where it won't exert any heeling moment, or where it will help counteract the overall moment exerted by the other forces acting on the boat (gravity, bouyancy, lateral resistance, and drag).
3) The direction of the kite's force doesn't change when the boat heels.
4) When the boat heels, the kite may exert a small rotational moment that helps stabilize the boat.
With no heeling moment, the driving force can theoretically be enormously greater, plus the upward component reduces the boat's displacement.

[Edited to make more sense]

Right on, Skippy. Good points. Want a job? ;-)

Dave

[Paul B]

Originally Posted by daveculp

Cool! A doubter.

Really?

Originally Posted by daveculp

W use 1/8" lines for between 35 and 70 meters which we believe are practically the smallest one can handle with gloves on. Smaller kites would need smaller lines which are dangerous to your hands.

Not sure I want to handle a highly loaded 0.125" line, let alone anything smaller. Sure wouldn't want it to wrap any body part, then load up. I'll bet something like that can do a nice job sawing through things like Tuff Luffs, or furled jibs (M24 style).

Originally Posted by daveculp

Most of our currently installed kites are aboard boats that race--Corsair Trimarans, several large multis (Afterburner on the West Coast, Alacrity on the East; both 50'ers, a cat and a tri); many of our kites are aboard one-off multis, in the US, Britain and Australia. Boats from 33-48'. We are constantly pushing for races for our customers to participate in. As with most new technology, organizers are wary of us; we've been banned from some races, embraced by others, and hotly talked about by almost all.

I've yet to see one used in a race, and you're not giving many details here or on your site. What races did Afterburner use their kite in?

Originally Posted by daveculp

Nope. We were scratched late from the Sydney Hobart (which went to windward this year).

Normal, right?

Originally Posted by daveculp

We are currently working on the TransPac (both the transpac and Chi-Mac are Americap races). Newly allowed multihulls in the Pacific Cup may carry kites (we're working on monos for this race, too). Americap requires polars and wind tunnel data--they say--on order to build a VPP for rating OutLeaders. We are not able to fund this work ourselves. Any ORCA race is encouraged to carry kites, but we just got this ruling, so none have, to date. NorCal PHRF is allowing kites on any boat they rate.

Hopefully Americap will die the death it deserves after these races, so no need for the data gathering for that. I would think you would be able to use an off the shelf system for data acquisition to build polars for a specific boat. I'll bet the ACC guys had the ability to do so, and I would expect Langman could do so as well.

PH should rate them, based on real performance, but it will be up to the clubs to allow them. That means PH should probably give provisional ratings until the real potential is determined.

Originally Posted by daveculp

Accurate statement. On our front page, paragraph 2 of our lead article, we admitted we blew the engineering on this kite, could not power it up on first flight. Also where we worked with AAPT's sailmaker. We re-engineered the kite and PAID THEIR SAILMAKER to make the necessary alterations. We still offer our comprehensive money-back performance guarantee--the only one in the business. FWIW, AAPT still owns their kite...

Of course they do. I'm sure it is a good advertising tool. I'd like to see them use it, but better yet let's see a leading OD boat use one in a competitive fleet. The rubber will hit the road there.

Originally Posted by daveculp

Nope. It has been very widely documented that we train new users of our kites without any other sails flying. The crew needs to learn what the kite will, and will not do without interference from other sails, then learn to fly--and launch--behind the main. All of the publicity shots of AAPT were taken during the first--the very first--flight of the giant kite on that boat. FWIW, watch this space; this kite is going to be given a Guinness world record for largest kite ever to pull a boat.

Widely documented? I didn't really get that from the Seahorse article. It seems strange that you would have to unbalance the boat like that.

I have a pair of Doc Martens. I'm going to try and get them a Guinness World Record for the biggerst pair of shoes ever on my feet. Maybe that's not on par with your record, but are you on par with the Hindu who lay on the ground and rolled across India?

Originally Posted by daveculp

I think I covered this above. Have you checked out our discussion list, at http://groups.yahoo.com/group/outleader? Have a look at the customer testimonials there, where folks tell us they've never sailed so fast, never felt so "on rails" sailing offwind, etc??

Jeezis, that guy Alan H is your big testimonial? He's proven, by his own comments on another Board, that he is a terrible sailor. I hope you get someone better than that soon. Seeing that kinda drops confidence in the comments.

Originally Posted by daveculp

Did you read about the older half-tonner in Perth we had 3-sail reaching with our kite--at 11 kts of boat speed (fair for a non-planing 40'er, eh?)?

I hope an "older Half-Tonner" wasn't a 40 footer. Maybe you mean One Tonner?

Originally Posted by daveculp

Have a look at the photos of the J24 pulling a "tugboat" wake in Sydney haarbor last December, doing 9+ kts: http://www.pacificsailingschool.com....bums/KiteShip/ ?

I've gone MUCH faster on J24s in the past. Let's see them race it a North Americans around the cans and see how they do.

Originally Posted by daveculp

Did you also read the bit about AAPT being able to pump out all water ballast when flying the kite? This makes the 11-ton boat 3 tons lighter. D'you suppose that may have some effect on her ability to plane out at speed?

I would imagine that they would sail "dry" downwind anyway.

Originally Posted by daveculp

AAPT are our customers, they spent a large amount of money to purchase our kite and to fly our people into Sydney for training; Nicorette are our competitors; how would you have put it, in our place?

Competitors? I would think you should consider Nicorette to be POTENTIAL CUSTOMERS.

Originally Posted by daveculp

I'm pulling your leg a little bit here, Paul. Your profile says you're in California. Why don't you get in touch with me, and I'll arrange for you to take a test sail? You can then come back here and tell of your own first-hand impressions, good or bad. I don't think I can offer more than that--

I'm taking the piss a bit as well. I'm in LoCal, not NorCal. If this actually catches on as a viable alternative I'm sure I'll have opportunities to Do It.

[daveculp]

Dude, I'm not gonna rise to any of the above. I've made you an offer. I've got boats up and down the coast, have steered you to a number of people who have done it, not pissed on it from the danger of their armchair.

We're inclusive in our approach; we'd love to include you. Frankly, I was always sure you'd stay away. Have fun anyways.

Dave