New Age Trawler/Motorsailer; Kite assisted PowerYacht

[apex1]

Looks like a possible solution in small scale, simple setup.

[brian eiland]

I believe one misunderstood concept with both 'pulling kites' and downwind sails is the fact that as your vessel starts to reach a reasonable speed in the same direction the apparent wind 'pushing' the kite or sail the force of that wind imparted to the kite or sail is greatly diminished. (if your vessel reaches 10kts in a 20kt wind, your kite only sees 10kts of wind, so your vessel will not likely see 10kts of speed, but MUCH less)

The para-kite form is a 'flyable' form, and utilizing this feature is important to make the best use of a 'downwind device'. Flying the kite allows one to double or triple the wind speed over the wing form of the kite or sail. Then remember that the pressure of the wind (on the kite) increases as the square of the velocity...much more power from a smaller kite.

[apex1]

Sure brian,
thats why I said "small" and "simple"

The aerodynamic wing kite has up to 8 times the power when flying figures (speed).

Regards
Richard

[Guillermo]

Looks neat and simple, indeed.
Although I don't believe a single person is able to deploy the kite (at the video, someone is taking care of keeping the boat going backwards while the guy at the bow deploys the kite), I think it can be of use for small motor boats, not only recreative but also commercial fishing ones. I specially like the apparent easyness to fly the kite again after dropping on sea surface, by simply going astern with engine.

Cheers.

[apex1]

Yes Guillermo, a waterstart is a good argument. But a "coming home" propulsion has no engine to go astern, when things go wrong. And of course two people to handle that system is one too much, no matter what they claim.

[Guillermo]

I'm not thinking about the kite as "coming home" option only, but as auxiliary power at all times when direction of wind allows. Even as the only means of propulsion if wind's strong enough. Particularly interesting for small commercial fishing boats. Maybe I'll put some work on this idea.

Cheers.

[brian eiland]

Another fellow sailor working towards some kite power

http://www.parlier.org/beyond_the_sea/eng/beyond_the_sea.php?beyond=4

http://www.parlier.org/beyond_the_sea/eng/espace_reserve.php

[brian eiland]

http://www.hiswasymposium.com/pdf/2009/Hiswa%20Symposium%202008%20Tom%20Schnackenberg.pdf

http://www.hiswasymposium.com/symposium_papers.asp

[Boston]

I'm not thinking about the kite as "coming home" option only, but as auxiliary power at all times when direction of wind allows. Even as the only means of propulsion if wind's strong enough. Particularly interesting for small commercial fishing boats. Maybe I'll put some work on this idea.

Cheers.

I was thinking that the if you want to fly a pattern to increase pull then hanging a pendulum off the kite kinda in the same position as were a para-foil pilot would be and using a sprint kinda like a clock does to maintain the motion and period of the swing you would have a nice little automated tracking system for the pattern you wanted to fly
with out all the electronics or at least with a minimum of electronics

that and a simple system of cables similar to U control cables in model airplanes for altitude control and attitude in a pinch
just a thought if it helps any

B

[brian eiland]

Just brought to my attention, this lady (Anne Quemere) kite-sailed across the Atlantic in '06, and now she is onto another adventure in the Pacific.

http://www.anne-quemere.com/

http://www.anne-quemere.com/indexgb.php

[Timothy]

I forgot where I read it but I think kites are being used to generate electricity through a mechanical linkage from the control lines to an alternator. I wonder if something similar could be adapted to work as secondary function for these "spiniker kites".

[Boston]

might be easier to just drag a prop behind you

[brian eiland]

http://www.hiswasymposium.com/pdf/2009/Hiswa%20Symposium%202008%20Tom%20Schnackenberg.pdf

http://www.hiswasymposium.com/symposium_papers.asp
The latest measurements made aboard the cargo ship “Michael A.“ of the
Wessels Shipping Company demonstrate how the towing kite propulsion system delivers far more than five times the performance per square meter of sail than traditional wind propulsion systems. With the help of the wind, the 160 square meter kite generates up to 8 metric tons of traction force – this approximately corresponds to the thrust of an Airbus A318 turbine engine.

“Our own measurements show that we were able to temporarily save far more than half the fuel by deploying SkySails in favourable wind conditions,” reports Gerd Wessels (37), managing director of the Wessels shipping company based in Haren/Ems, adding that “alternatively we were able to increase the ship’s cruising speed from 10 to 11.6 knots with the help of this towing kite propulsion.”

Each of the shipping company’s next three new 88-meter, multipurpose sister ships with a deadweight capacity of some 3,700 metric tons and nearly 1,500 kW of power will be fitted with a 160 m² kite. With favourable wind conditions, a kite of this size can generate up to 8 tons of traction power. For comparison: in order to reach a cruising speed of 11 knots, these ships require approx. 11 tons of thrust.

...excerpt from http://hiswasymposium.com/symposium-papers
Vessel propulsion using kites
Stephan Brabeck (Skysails Gmbh & Co KG)
Tom Schnackenberg (North Sails A/S)

PDF document (http://hiswasymposium.com/assets/files/pdf/2009/Hiswa%20Symposium%202008%20Tom%20Schnackenberg.pdf)

[dskira]

At 40 mph (Force 8 which is gale force)) the wind pressure is 6 Lbs per square feet.
The kite they talk is 1600 square feet, which means 9600 Lbs of thrust which means 4.5 tons.
I am missing something? How they come to 8 tons?
It must be an explanation I am sure.

As for the comparison with a turbine engine, it is quite inaccurate, you can't mix apple and orange. I am surprise of the lake of seriousness, since by force 0 the kite develop 0 ton of thrust and the turbine still developing the same amount of thrust.
And they always talk about the perfect condition. You do not have perfect condition at sea.

Daniel

[apex1]

At 40 mph (Force 8 which is gale force)) the wind pressure is 6 Lbs per square feet.
The kite they talk is 1600 square feet, which means 9600 Lbs of thrust which means 4.5 tons.
I am missing something? How they come to 8 tons?
It must be an explanation I am sure.
Daniel

The kite flies a 8 figure steered by computer. That makes the aerodynamic lift add to the pressure forces on the kite.
These 8 tonnes are a proven fact (and not the whole truth, it can be more).

The "perfect condition" is not the every day condition, true, but due to the heighth it is found quite often.

The info provided is BTW not new! It is from 2008. Meanwhile there are several more ships operating with the Skysails system, and ALL are fully satisfied.

I guess we will have affordable, yacht sized systems within the next 3- 5 years.

Regards
Richard

[dskira]

The kite flies a 8 figure steered by computer. That makes the aerodynamic lift add to the pressure forces on the kite.
These 8 tonnes are a proven fact (and not the whole truth, it can be more).

The "perfect condition" is not the every day condition, true, but due to the heighth it is found quite often.

The info provided is BTW not new! It is from 2008. Meanwhile there are several more ships operating with the Skysails system, and ALL are fully satisfied.

I guess we will have affordable, yacht sized systems within the next 3- 5 years.

Regards
Richard

OK, I understand.
Thank you for the explanation.
I saw a picture of the 160 Sq. meter they are talking about associate with the ship Belouga.
This is the picture:

http://everydayboats.com/images/mvbelugaskysails.jpg

Daniel

[brian eiland]

Double the wind speed (apparent wind from 'flying' the kite), quadrupal the wind pressure force.

[dskira]

Make sense Brian.
When I look at the picture I observed a slight heel. The red paint in the left is slightly less that the red on the right (looking at the picture, the inverse for the ship.) It can be because the vessel turn, or it can be effectively the force of the kite.
Interesting.
Thanks both.

Daniel

[Boston]

kite moves in a figure eight pattern Daniel, the wind forces on it are higher than if it was just stationary relative to the boat

[apex1]

Almost no heel Daniel..............

http://www.skysails.info/

[dskira]

Almost no heel Daniel..............

http://www.skysails.info/

I am quite intrigued by these pictures. Thank you for posting.
One seams to be on a good stream of wind.
Height motion? Like my kite as a kid?
Well I have a lot to reassess in my mind, perhaps I am thinking to much as a sailing gear, and it is not, it is closer to a flying gear almost. So the rules are different.
It caught my interest and I have to put my mind ready for something very unusual and very far from my own logic.
Not an easy task for a stubborn like me.
I am going to start reading seriously about that kite propulsion.

I will be not left behind :D

Daniel

[apex1]

I am quite intrigued by these pictures. Thank you for posting.
One seams to be on a good stream of wind.
Height motion? Like my kite as a kid?
Well I have a lot to reassess in my mind, perhaps I am thinking to much as a sailing gear, and it is not, it is closer to a flying gear almost. So the rules are different.
It caught my interest and I have to put my mind ready for something very unusual and very far from my own logic.
Not an easy task for a stubborn like me.
I am going to start reading seriously about that kite propulsion.

I will be not left behind :D

Daniel

When they come down with size and price, and that will happen soon, that will become the standard "get home" propulsion on every other long range boat.
And we will see many more single engine "trawlers" than today.

I am following them since the very beginning, a very impressive story.

Richard

[Guillermo]

Things are not being easy for Skysails in spite of the enormous effort they are doing. I've met them last spring in Vigo where they gave another presentation on the system and the present development and commercializing stage.

Although the system already pays for itself in three or four years when used in the right ship and route, I think they will be able to come down with prices when production is at full speed. Anyway I think it's going to take time since it comes to the yachting industry.

[FAST FRED]

"And we will see many more single engine "trawlers" than today."

Most of the oxymoron "fast trawlers" have 2 engines and seldom have enough fuel for a half day of fast travel.

The folks now going offshore in displacement boats ARE ALREADY single engine engine , tho a few will need "get home engines" if the marinization installed is not really industrial strength .

FF

[apex1]

Things are not being easy for Skysails in spite of the enormous effort they are doing. I've met them last spring in Vigo where they gave another presentation on the system and the present development and commercializing stage.

Although the system already pays for itself in three or four years when used in the right ship and route, I think they will be able to come down with prices when production is at full speed. Anyway I think it's going to take time since it comes to the yachting industry.

Sure, they have no free ride with setting up such business. And they could survive the first years only due to the fact, that the main supporter was a modern thinking, unconventional shipping company, "Beluga".
But recent info made clear, they have the yacht market in focus and are aware of the great potential.


Most of the oxymoron "fast trawlers" have 2 engines and seldom have enough fuel for a half day of fast travel.

True, and that cannot be the market for a kite propulsion anyway.

The folks now going offshore in displacement boats ARE ALREADY single engine engine , tho a few will need "get home engines" if the marinization installed is not really industrial strength .
FF

As true, to some extend. Many of the passagemaking displ. vessels today are already single engine, though not all.
The best selling so named "Trawler" on the market comes quite often with a dual engine setup. And if it is single, it has a tiny "get home engine" with a Gori prop.
Thats all belt and suspenders philosophy and shows clearly how inexperienced the customers even in this market segment are.
But here the kite will bite.

Regards
Richard

[dskira]

Sure, they have no free ride with setting up such business. And they could survive the first years only due to the fact, that the main supporter was a modern thinking, unconventional shipping company, "Beluga".
But recent info made clear, they have the yacht market in focus and are aware of the great potential.



As true, to some extend. Many of the passagemaking displ. vessels today are already single engine, though not all.
The best selling so named "Trawler" on the market comes quite often with a dual engine setup. And if it is single, it has a tiny "get home engine" with a Gori prop.
Thats all belt and suspenders philosophy and shows clearly how inexperienced the customers even in this market segment are.
But here the kite will bite.

Regards
Richard

Richard,
Why they didn't start on yacht, it is smaller, less expensive, and far easier to develop?

[apex1]

Richard,
Why they didn't start on yacht, it is smaller, less expensive, and far easier to develop?

The computer system is a expensive device that does not scale down easily to yacht dimensions (costwise).
And the first supporter was Beluga shipping.

[dskira]

The computer system is a expensive device that does not scale down easily to yacht dimensions (costwise).
And the first supporter was Beluga shipping.

Make sense,
I didn't thought about the computer angle.
Thanks

Daniel

[wardd]

I dont see the computer as a major cost, the standard fast pc would have enough power

I think the actuators and programing would be the costly items

[apex1]

I dont see the computer as a major cost, the standard fast pc would have enough power

I think the actuators and programing would be the costly items

It was meant that way...............thanks.

[Tad]

In the paper Brian references above the acquisition and installation cost (2008) was 465,000 euros.........and yearly maintenance about 45,000....... with today's tiny shipping margins it will take some time to recover that.......

[apex1]

TAD

I don´t think so. The shipping companies have ordered the system for all newbuild vessels after testing for one and 3 years respectively.

IFO 180 or 380 at 430$ tonne makes the kite cost equivalent to 1200 tonnes of fuel. They are easily burned on one roundtrip EU / US east coast.

[mikeharwood]

Hello,

For people interested in smaller kites, here is an link
describing two journeys using the Omega Sail kite.

Mike

http://www.omegasails.com/blog

[apex1]

Hello,
For people interested in smaller kites, here is an link
describing two journeys using the Omega Sail kite.
Mike

Cute system,

we had that here already in the past discussions.

[brian eiland]

The computer system is a expensive device that does not scale down easily to yacht dimensions (costwise).
And the first supporter was Beluga shipping.
The whole integration of the routing systems and kite flying system was no easy or inexpensive project...less likely a single or several yacht owners would buy into this development cost.

If the fuel prices had continued to skyrocket they wouldn't be experiencing as much trouble selling this idea to the big guys...the shipowners. And you can bet this will eventually happen in the not to distant future...big fuel prices coming.

Meanwhile I suspect there is a growing interest from the yachting groups that a few select applications could be good publizity for SkySails...maybe why they might consider this at the moment...until fuel prices force the issues.

[brian eiland]

Hello,

For people interested in smaller kites, here is an link
describing two journeys using the Omega Sail kite.

Mike

http://www.omegasails.com/blog
Every little step adds to the equation.

But note that this is not really a 'flying' kite in the sense that it is an aero-wing like the Skysail kite. So it won't go upwind, nor likely generate extra force by apparant wind flying. It will pull you along, but that force will deminish as you go faster.

[Guillermo]

The biggest problems for Skysails were not related with computing or kite control but rather 'mechanical ones', as far as I know. Things like the different elongation rate of wiring and rope for the traction cable, the full automatizing of the launching-recovering system, etc.

They have invested well over 15 million euros in development and so they will have to sell a lot to recover that. There was a project for a Robert Humphrey designed pleasure trimaran, but never went ahead the designing stage.

[mikeharwood]

I think the Omega Sails kite is intended as a very simple
low cost kite, that does´t require constant attention (flying).

It provides range extension for power craft on off wind courses.
They managed to sail a Catalac catamaran from the Canaries
to Antilles in approx 30 days using zero fuel.

Mike

[brian eiland]

Here is a fellow out in New Caledonia that is doing some very creative experimentations with tri-hull designs...

....interesting subject thread, and photos, and prototypes:

http://www.boatdesign.net/forums/boat-design/trimaran-motorboat-stabilized-monohull-29665-4.html

[brian eiland]

Maybe there are some lessons to be learned from the success of this new hybrid Greenline vessel:

http://www.greenlinehybrid.com/



PS: just found this rather big discussion of this vessel over here on the forums,
http://www.boatdesign.net/forums/hybrid/most-inspiring-proven-hybrid-34228.html

[Tad]

See my blog post for today.......http://blog.tadroberts.ca/2011/01/the-hybrid-myth-greenline-33/

[Boston]

pretty scathing review Tad but it makes sense

cheers
and always interesting to read your stuff
B

[Guillermo]

I quite agree with your opinion about the late "green myth" in motorboating Tad. Nothing as green as a efficient diesel engine and efficient prop in a efficient hull at efficient speed. :cool:

The only real and fully "green" propulsion in boating is windpower, as it has always been. And even this can be questioned in terms of economic efficiency depending on use! ;)

Cheers.

[wardd]

don't forget beans and ors

[Tad]

Guillermo....

Thanks for your note and the best of the season to you and your family....

Yes, as we've discussed before people apparently don't see that being "green" requires one to stop consuming.......

The greenest solution I can see right now is buy an old Bayliner (32's are available at $25k here, twin gas) and install one of the smallest VW diesels....though rebuilding an old Perkins would be even better.....:p

[tom28571]

pretty scathing review Tad but it makes sense

cheers
and always interesting to read your stuff
B

Not really scathing. Mainly the intelligent application of well known basic principles.

[brian eiland]

Here is another interesting hybrid discussion:

http://www.boatdesign.net/forums/hybrid/nanni-diesel-hybrid-propulsion-35546.html

Hello everybody, i am a R&D engineer at Nanni Industries. I have designed and am developing the current intercalated hybrid propulsion system based on Iskra electronics. In particular, my job is to develop the mechanical and electrical marine power transmissions of our engines.
Feel free to ask any questions or comment.

[Chuck Losness]

Tad,
I have been thinking of doing just what you suggest for my next boat. Using the Bayliner 32 as an example what size engine would you need to be able to cruise at 8 knots. I would think that two 40 hp perkins 4108's diesels should be sufficient in this example. Or maybe two Kubuto diesels. Any idea on what the fuel consumption might be?

[brian eiland]

A cargo ship has set off from Bremen to Venezuela to gain first-hand experience being towed partly by wind power. The newly built cargo vessel was towed by wind propulsion for the first time in the North Sea this month. The 160m2 SkySail supported the main engine of the 132m long Carrier MS “Beluga SkySails” of the Bremen-based Beluga Shipping with approx. five tons of tractive force at a low wind speed.

The invention is that of a Hamburg-based company SkySails GmbH & Co.

“The maiden voyage marks the beginning of the practical testing during regular shipping operations of the SkySails-System. During the next few months we will finally be able to prove that our technology works in practice und significantly reduces fuel consumption and emissions,” says Stephan Wrage, Managing Director, SkySails.

Parallel and in addition to the practical tests on the MS “Beluga SkySails”, the SkySails technology is advanced and optimized for series production readiness on further ships.

Stephan Brabeck, Technical Manager at SkySails: “Certainly, the daily routine at sea will still bear many challenges for SkySails. It is thus now particularly important to raise the manageability and robustness of the system to the level demanded by our customers. We will have to face up to many challenges and in the process learn many very valuable lessons.”

The shipping company and the manufacturer calculate that by using the towing kite system, a ship’s average annual fuel costs can be reduced by between 10% and 35%, depending on the prevailing wind conditions. Under optimal wind conditions, SkySails estimates that fuel consumption can sometimes be cut by up to 50%. The first results are to be expected in the next few months.

“Interest in the SkySails technology among shipping companies from all over the world was already high before, but especially during the last year and in light of the rising oil prices it has increased considerably,” states founder of the company Stephan Wrage.

They hope the state-of-the-art kite will help reduce carbon dioxide emissions, as it tugs the ship.Fuel burnt by ships accounts for 4% of global CO2 emissions - twice as much as the aviation industry produces.

For the past ten years, Hamburg-based SkySails has been engineering and producing what are essentially giant kites, designed to help ships reduce their fuel use by catching the wind and pulling them across the surface of the ocean. The system was put into regular shipping use for the first time in 2008, when one of the kites was attached to the 132-meter (433-foot) multi purpose heavy lift carrier MS Beluga SkySails. Now, Cargill Ocean Transportation has announced that it plans to use the technology on one of its long-term charter ships, a vessel of between 25,000 and 30,000 deadweight tonnes (27,558 to 33,069 US tons). It will be the largest kite-assisted ship in the world.

The kite will measure 320 square meters (382.7 square yards), and will fly ahead of the ship in a figure-8 pattern at a height of 100 to 420 meters (328 to 1,378 feet). Its flight path will be controlled by an automated system, and the kite itself will be launched and retrieved via a winch-equipped telescoping tower on the bow – definitely a better approach than having someone desperately bracing themselves against the deck of the ship, while clutching a couple of control lines! Information regarding the system's operation will be displayed on a monitor on the ship's bridge, although it is said to require a minimum of input from the crew.

Use of a SkySails sysytem is claimed to reduce a cargo vessel's fuel consumption by an average of 10 to 35 percent annually, and by up to 50 percent temporarily. Due to its "dynamic flight maneuvers," the kite reportedly generates 5 to 25 times more power per square meter sail area than a conventional sail. A study by the United Nations' International Maritime Organization suggested that up to 100 million tonnes (110.2 million US tons) of carbon dioxide could be saved each year, if the technology was broadly applied to the world's merchant fleet.

Cargill plans to install the SkySails system this December, and hopes to have it fully operational within the first quarter of 2012.
http://www.gizmag.com/cargill-ship-will-be-largest-ever-to-utilize-kite-power/18005/

[Guillermo]

SkySails seem to be slowly but firmly going ahead. Good for them.
Although I do not agree reducing CO2 emissions is good for the environment. ;) Only good from the point of view of saving fuel costs.

Cheers.

[brian eiland]

I think the new fuel cost are going to drive a lot of new peojects.

Did you see this new Feadship motorsailer? (don't know that I would classify it a motorsailer, but rather a sail stablized power vessel)
http://www.yachtforums.com/forums/feadship-yacht/15513-some-pics-feadship-motor-sailor.html

[Guillermo]

No, I hadn't see it. I'd say it's a 80-20 motorsailer or the like....
Probably those small sails are not very effective to stabilize the boat. Not to push it at a decent speed except in strong winds. In my opinion a waste of money, but.....

[Tad]

new Feadship motorsailer?
http://www.yachtforums.com/forums/feadship-yacht/15513-some-pics-feadship-motor-sailor.html

Far from new.......actually about 40 years old now........

[Pericles]

Astonishing. Three of the best contributors to this forum on one page, Brian Eiland, Guillermo and Tad in that order. Excellent.

[TeddyDiver]

Far from new.......actually about 40 years old now........
Considering Brians age maybe.. ;)

[peter radclyffe]

a 20 meter motor sailer, 5.5 mt beam, 3 mt draught
http://i791.photobucket.com/albums/yy195/helpME7/img674-1.jpg

[u4ea32]

I nearly always agree with Tad, and I agree with Tad's review of the Greenline: essentially, that complex systems usually end up contributing more to problems than they do to advantages.

I think that the opportunity to be "green" is in consuming less. Luckily, that means the original cost can be less (less systems, less structure, less stuff), and that the cost of ownership can be less (less fuel, less things to break, cheaper things to repair).

I think that many of the "normal parameters" for yacht designs are obsolete, and lead to these 1nmpg or so boats.

Some of you may remember when really high performance Maxi sailing yachts weighed about 100,000 lbs (mid 60's until Merlin in late 70's). Ragtime, and then Merlin, demonstrated that a maxi racing yacht could be really light, and therefore really cheap to build and own. When the boats were originally built, nearly everyone assumed the boats would be throw away boats. Yet Ragtime and Merlin have done more Transpac races than any other yachts. After 45 years Ragtime is still going strong. Merlin was sort of hacked up a few years ago, but its not far off its top condition at about 35 years of age. Both of these boats weigh only about 25,000 lbs: this is a huge difference. The fleet of sleds that followed Merlin, and subsequent yachts such as the IMOCA 60s, Volvo 70s, etc. have continued to demonstrate that very light displacement yachts can take the worst the ocean can offer, while achieving amazing performance under sustained heavy sea conditions.

Today, we tend to assume that L/D of 200 or 300 is reasonable for safe vessels. I suggest that L/D of 20 is far more green, and very easily and inexpensively achievable today.

With light designs, and appropriate discipline applied to outfitting, green boats are pretty much automatic. No weird technologies, configurations, or breakthroughs required. Just light and long (very low LD) and simple.

[Boston]

I think that the opportunity to be "green" is in consuming less. Luckily, that means the original cost can be less (less systems, less structure, less stuff), and that the cost of ownership can be less (less fuel, less things to break, cheaper things to repair).

I think that many of the "normal parameters" for yacht designs are obsolete, and lead to these 1nmpg or so boats.

I wouldn't presume to comment on one of the greats like Peters design just like I stayed off the perfect passage-maker thread other than as excellent reading material, but one thing I can speak to is conservation, both in an environmental sense and in the energy sense.

In a nut shell, simple conservation wont really work. The human population over the last 10 years rose slightly more than 10%. The reality is none of us are using 10% less energy than we where 10 years ago, so all in all to conserve enough energy to make up for the 9 billion people we are about to have on this planet we would have to reduce our energy use per person by at least one percent a year over the next 30 years, not happening.

The only real chance of making up for there being so many more of us is to find alternative fuels like bio-diesels and other green technologies. So going green and making it viable is key to any future practices that can be expected to last.

The fuel efficiency of a boat is about the lowest of any vehicle, they simply have to deal with more drag than planes and cars. Although planes actually get pretty crappy millage as well, (5 mpg for a large passenger jet) deal is although improvements can and are being made its the type of fuel that really needs to change. after that the efficiency is secondary.

[FAST FRED]

"The only real chance of making up for there being so many more of us is to find alternative fuels like bio-diesels and other green technologies."

Actually if the worlds politicoes would stay out of the "problem" , the normal supply and demand will price the worlds energy properly.

The USA today is paying for the destruction of 41% of our corn crop , for election cash donations.

And then some claim they cant understand why food prices go up, so we should kill off a couple of billion "useless" folks ,as Margret Sanger and W Wilson early progressives suggested..

FF

[brian eiland]

John wrote recently on a forum discussion:

We are installing the winch and gear to fly a kite like the Skysails system off the 42 m Power tri. We will develop our own control system. The kite is a large version of a normal kite boarding kite. The numbers show that if we can fly the kite in a pattern at 300 m high we can generate enough power to pull the boat under kite alone at 15 knots.

The trick is the height of the kite. At 300 meters the wind speed is higher and you can make the kite travel further and faster across the sky. This is what generates the higher power.

With the low drag of the power tri this concept becomes realistic as a significant power source, where the boat can sail at a good speed. Not just fuel saving.
****************************************
http://www.john-shuttleworth.com/New.html
Orion Shuttleworth has spent the past 5 years working for Bernard Olesinski, a specialist in powerboat design, primarily concentrating on deck design and styling for the Princess Yachts. He has developed extensive skills in 3 D modelling with Unigraphics NX surfacing programme, and brings a wealth of Big Boat design experience and understanding of LY2 and RINA regulations to offer as a service to our design office.

His expertise in 3D rendering can immediately be seen in his work on the new Power 41 meter Tri, currently building in China, in which he is playing a significant role in all aspects of the final stages of the design and preparing for classification under the Hong Kong flag authority.

Orion is also bringing his kiteboarding extpertise to developing a kite assist system for the 41 m Superyacht. Current systems for ships are very heavy and complex. Orion is working on a system that uses conventional kites which can be water launched, or launched off the deck of the boat. Progress will be reported on our site.

[FAST FRED]

"The trick is the height of the kite. At 300 meters the wind speed is higher "

At 300 meters you might need a radar transponder and some sort of lights to avoid catching air craft and helicopters.

The liability insurance could easily outweigh any fuel savings.

FF

[Boston]

thats kinda a frightening thought Fred
leave it to the insurance agent to find another way to gouge the public eh

slap a blinking light on it and call it good

[brian eiland]

I would surely hope aircraft are not out at sea flying at only 1000 foot altitudes...unless they are stunt pilots :?:

[Pericles]

Brian,

In the UK, we have this:

"Since article 86 does apply, kites in the UK are restricted to flying below 60 metres (around 196 feet). In fact the restriction is 30 metres within the aerodrome traffic zone of a notified aerodrome during the notified operating hours of that aerodrome (article 86.2b (iv). "

http://www.zenoshrdlu.com/kapstuff/KAPUKLaw.html

It is specific about ground level, which means hills, valleys and especially headlands over the sea present interesting dilemmas. I suppose compliance would depend on wind direction.

http://en.wikipedia.org/wiki/Beachy_Head

However, the ceiling for traction kites at sea, out of sight of land during daylight might be an area on which there is no ruling as yet. I think that Bernard Olesinski, John Shuttleworth and Princess Yachts will have looked into any legislation vis-à-vis their new design.

It seems to be common practice for commercial shipping to switch off their radar on long ocean crossings to reduce wear and tear on the equipment and to avoid false alarms from whales or other objects floating in the water, so a radar reflector might not be necessary. One would hope such vessels would keep a good watch and see the traction kite. There's no substitute for a pair of eyeballs scanning the skyline.

http://findarticles.com/p/articles/mi_hb3120/is_11_80/ai_n31011446/

Rigging lights on the kite for sailing at night, is straightforward I would have thought. "Second star on the right, and straight on 'til morning".

Regards,

Perry

[FAST FRED]

"I would surely hope aircraft are not out at sea flying at only 1000 foot altitudes...unless they are stunt pilots."


Sorry, but the US Navy Patrol planes I flew (SP2-7 or P2V7) regularly ran patrols at under 1000 ft many at 500, day or night.

In ASW operations 100ft was the norm , looking for magnetic hull contact.

Not stunt pilots , just junior JG's following Da Book.

FF

[brian eiland]

A pleasure powerboat crosses the Atlantic with 30 liters of fuel.

http://www.kitepowerboat.com/?lang=en

[FAST FRED]

The site claimed he would be going in March 2010,

I didn't find anywhere if they went or were any faster than an empty coke can.

FF

[u4ea32]

35 days, 4 hours, 8 minutes, but that's not a complete Atlantic crossing, only from the Canaries to the West Indies (Guadaloupe). This is two to three times as long as a typical cruising sailboat makes the same crossing. In the 2010 ARC, nearly everyone did the crossing in 11 to 16 days, a few faster, almost none slower.

In other words, this kite powered boat is a pig.

[Boston]

bummer
I've been hoping someone would come up with a simple computer program to control these things

[Pericles]

This kite powered vessel is a pleasure powerboat catamaran that could not have made the trip any other way, 35 days or nay. Comparing this vessel with a cruising sailboat is comparing chalk with cheese.

http://www.kitepowerboat.com/?lang=en

OTOH a £3 million Gunboat 66 would beat all the 2010 ARC competitors. C'mon lottery, make me rich. :(:)

http://www.youtube.com/watch?v=vdqXoIhg0dA&feature=related

http://www.youtube.com/watch?v=a6fHd0UIFJk&NR=1

[brian eiland]

35 days, 4 hours, 8 minutes, but that's not a complete Atlantic crossing, only from the Canaries to the West Indies (Guadaloupe). This is two to three times as long as a typical cruising sailboat makes the same crossing. In the 2010 ARC, nearly everyone did the crossing in 11 to 16 days, a few faster, almost none slower.

In other words, this kite powered boat is a pig.
Granted it was slow...but these are the early days of experimentation...and some with very small budgets to experiment with.

[FAST FRED]

"Granted it was slow...but these are the early days of experimentation."

the question remains,

Did it beat an empty bottle?

FF

[Pericles]

Si hombre FF,

There were MT bottles of JD floating behind in the wake, bobbing along and slowly dropping behind. All contained the same message, "Send more (hic) JD".

P

[brian eiland]

Have you seen the new Shuttleworth power trimaran:

http://www.john-shuttleworth.com/adastra.html

I understand that John's son Orion is working on some kite-power vessel concepts....wonder if they involve this vessel somewhere down the road?

[Guillermo]

"Adastra" is the result of more than 5 years of design and discussion with the owners

Wow!

[brian eiland]

"Catamaran and trimaran hull designs are faster, more stable in high sea states, have similar internal volumes as single-hull ships, and are more fuel-efficient than conventional hull designs. In addition, a trimaran's outriggers add stand-off range to the center hull, where vital equipment (computers, propulsion, living spaces) would be located. This stand-off range would make the ship more resistant to damage from attack."

http://www.g2mil.com/trimaran.htm

[brian eiland]

http://www.motorship.com/news101/triton-trials-trimaran-form

"The result is a main hull having a round bilge shape with underwater sections approaching semi-circular shape amidships. A gentle rise of the bottom lines aft leads to a counter-stern transom with minimal immersion. The side hulls are of multi-chine design on the outboard face with a flat plain inboard face for ease of manufacture.
The demonstrator was built at two thirds the size of a full-scale warship"


"The trimaran design is faster and more manoeuvrable than an equivalent sized mono-hulled craft, says QinetiQ. It adds that Triton has proved that the triple-hull design offers a reduction in drag of 20% compared to a conventional mono-hull vessel"


"The extensive sea trials have been undertaken in a wide range of weather conditions up to a sea state of 7 to 8 with the ship sailing at short notice to stormy sea areas around Ireland, south Iceland and off the Norwegian coast. Using a star trajectory pattern the trimaran was subjected to every conceivable wave pattern. QinetiQ says there were very few instances where it shipped green seas over the bow. Special attention was paid to the slamming effects under the decks linking the hulls. QinetiQ says the vessel?s handling capabilities have validated the designers? claims by confirming the naval architectural performance."


" Bob Short, QinetiQ?s RV Triton programme manager, says that Triton has already gone a long way to validating earlier research and has demonstrated the considerable benefits associated with triple-hulled vessels. He is also quietly confident that trimarans have a huge potential commercial application worldwide and the agreement with Vosper Thornycroft strengthens the UK?s position as a world leader in trimaran technology.
Ultimately, however, one has to recognise that a fundamentally conservative industry such as shipping will take some convincing before it will commit hard cash to a new hull type"

[peter radclyffe]

7 to 8 is not every sea state

[brian eiland]

7 to 8 is not every sea state
Did it say that??

This is what I read, "wide range of weather conditions up to a sea state of 7 to 8 with the ship sailing at short notice to stormy sea areas around Ireland, south Iceland and off the Norwegian coast. Using a star trajectory pattern the trimaran was subjected to every conceivable wave pattern"

[peter radclyffe]

you cannot subject a vessel to every conceivable wave pattern under force 8

[Jeremy Harris]

MV Triton was my ex-bosses (Chris Stonehouse, for those that may know of him) pet project that started back in the late 80's, early nineties, long before QinetiQ came along. It was designed and built back when UK defence research was wholly government owned and its operation was inherited by Qinetiq as part of the government sell-off about five years ago.

It was a technology demonstrator, designed to test whether the trimaran concept worked at relatively small scale (the reduced scale was to keep the costs down and make the project affordable). A consequence of the reduced scale was an acknowledgement that not everything could be fully evaluated, including the ability to operate in all possible sea states.

The idea was to gather data and evaluate the pro's and con's of using this configuration for future warships. Like a lot of good ideas, this 20+ year old one has been overtaken by events somewhat, in that it seems highly unlikely that the UK will build any new warships for some time, as the country is virtually bankrupt (largely thanks to having to bail out the banks).

At the time that the ideas behind RV Triton were first mooted, the importance of a stable deck for ASW helo ops was paramount, as we were still very much in Cold War mode, with defence resources heavily focussed on detecting and countering the ballistic nuclear missile subs that passed through Northern waters on their way out to the open Atlantic. With the re-focussing of naval warfare to support small scale amphibious ops the ASW role diminished, so some of the features that were used to justify the project reduced in significance.

I suspect that, as air and sea warfare evolves to become unmanned vehicle/submarine/heavy transport focussed the need for a full scale ship like RV Triton may reduce even further, particularly given that it is not a particularly cheap hull form to build or maintain through life.

[Pericles]

Peter,

It is not really possible to construct a ship that will survive every possible sea state; that much is certain. I suppose the final sentence of the QinetiQ statement quoted by Brian should have read:

"the trimaran was subjected to every conceivable wave pattern, seen during sea states of 7 - 8. "

It's worth reiterating the words of Bob Short, QinetiQ's RV Triton programme manager:

"Ultimately, however, one has to recognise that a fundamentally conservative industry such as shipping will take some convincing before it will commit hard cash to a new hull type"

Warships are not the safest of environments. It goes with the territory and the trimaran hull design seems to work well for the purposes for which USS Independence LCS-2 was constructed. Horses for courses!

http://en.wikipedia.org/wiki/Littoral_combat_ship

It's too damn bad that the UK is building two aircraft carriers, that are having to be modified at great cost, so as to launch French "Rafales".

http://www.thisismoney.co.uk/news/article.html?in_article_id=407244&in_page_id=2

P

[Jeremy Harris]

"Ultimately, however, one has to recognise that a fundamentally conservative industry such as shipping will take some convincing before it will commit hard cash to a new hull type"


Very true. At the time that Triton was conceived we were still feeling the aftershocks of the "short fat" vs "long thin" warship debate. A great deal of time and money had gone into showing that fatter warships performed better, carried more stores, so had greater endurance and were better sea-keepers than long thin ships. The need for high burst speed (35kts or so) that had driven the long thin designs had diminished and stability and the ability to have greater endurance before needing re-supply was of greater importance. Would the Lords of the Admiralty and shipbuilders listen? would they heck as like! The result was that the next generation of warships were pretty much as long and thin as their predecessors, despite all the additional diffculties this gave those who wanted a more stable fighting platform (those involved in helo ops, for one, hated this decision).

I am reasonably certain that when Chris made his final argument to persuade the powers that be to build Triton, part of the reason he was allowed to go ahead was the hope that it would appease the vocal supporters of the "short fat" designs, yet still look suitably long and thin...........

[peter radclyffe]

i agree Perry

[brian eiland]

......The power would be a single main engine sized to develop the vessel’s desired top speed, and it could transmit this power by conventional shaft/prop arrangement, or with a azimuthing Volvo IPS dual prop unit, or via a retractable azimuthing Rim-Drive prop unit as I included on my latest dynarig motorsailer design...
This new ZF Marine 'Single Pod Unit' looks to be an applicable power transmission unit for this single-engined vessel.

"ZF Marine Group introduces a revolutionary new approach to Pod drive and joystick control technology in small pleasure craft applications, which extends its availability to a larger segment of the pleasure boat market. In conjunction with SeaVee boats, ZF Marine has developed a complete propulsion system solution around a center console sport fishing application that will offer joystick control and maneuverability while employing the pleasure craft industry’s first single Pod drive line. The heart of the propulsion package from ZF Marine incorporates 3 main components. The ZF 2800 Series Pod drive rated at 480hp. This Pod has been redesigned to offer 180 degrees of total movement, 90 degrees of rotation to both port and starboard from the cent reline. The ZF 185 AC Thruster that introduced to the market at last year’s Fort Lauderdale show. The ZF 185 Thruster is designed to offer proportional thrust, 30 minute continuous duty cycle, and smooth, quiet operation thanks to a patented thruster tube design. ZF Marine’s proven SmartCommand controls with Joystick. The joystick system is engaged when the Easidock feature is activated via a button touch on the SmartCommand control head. During normal at sea operation the 2800 Pod drive is restricted to 30 degrees of movement in either direction from center. This restriction of movement is released in Easidock mode and the POD now has full 180 degree movement. The ZF 185 AC Thruster is also brought online at this time. As the vessel operator directs the joystick in any direction or combination of directions the joystick system incorporates POD thrust and varying amounts of thrust from the bow thruster. Proportional control of the thruster means smooth engagement, and only as much thrust as needed to move the vessel in the desired direction. Proportional thrust, combined with an electronic compass tied to the main JMS control unit means there is no vessel yaw during sideways movement. ZF Marine’s patented iAnchor station keeping functionality is also included in the Single Pod System. With the press of a button, iAnchor will compensate for wind and current holding the vessel’s position to as little as a 3 foot radius."

[brian eiland]

...I suspect that, as air and sea warfare evolves to become unmanned vehicle/submarine/heavy transport focussed the need for a full scale ship like RV Triton may reduce even further, particularly given that it is not a particularly cheap hull form to build or maintain through life.
I might offer an alternative view here. I would agree that the future navys may not have need of as many BIG ships as they have had in the past, and as such smaller ships such as this Triton vessel might do rather well in the comparision of the job they can do in comparsion to their single-hull counterparts that invariable grow in size from their original specs to their ultimate configuration.... Prime example the competing littorial ship design by Lockheed; this is a fuel hungry ship that only has half the speed capabilities of the tri-hull.

As far as cheap to operate, look at the fuel consumptions of these two. Just the fuel savings of the tri-hull type should more than pay for her extra maintainence. Construction cost couldn't be that much more, if you consider that very likely the cost of the hull of a major warship couldn't be more than 15% of the total cost of the ship, so even if you doubled the cost of the hull itself (not likely), you didn't increase the total price of the finished ship that much.

[FAST FRED]

"I would agree that the future navys may not have need of as many BIG ships as they have had in the past,"

The newest low cost Hypersonic ship attack missles from China may make ANY surface ship risky.

Since war is an economic venture a dozen warheads VS the cost of a Capital ship is a no brainer.

Perhaps the new ,still in development ,Laser cannons will make 7 dozen incoming a minor problem?

[brian eiland]

I always thought the 'arsenal ship', particularly the semi-submersible one, was a good idea. Station these off the coast of any country that threatens another with missiles and catch those missiles on their way up after launch...MUCH MORE EFFECTIVE at interception. Being semi-submersible they would present a very low target profile themselves.

http://newwars.wordpress.com/2009/09/30/arsenal-ships-for-ballistic-missile-defense/

As an alternative to our over-worked missile battleships in the role of ABM defense, we would suggest reviving the 1990s proposal for an Arsenal Ship. You may recall this revolutionary hull design as an attempt to replace the Iowa class dreadnoughts with a low cost “missile barge”, until canceled in favor of a more traditional and more costly Zumwalt class destroyer. The arsenal ship was a great idea which never saw the light of day, but also refused to die out completely.

The modern concept would be to use a low-cost ship hull, preferably of mercantile specifications (T-AKE?) equipped with vertical launchers (VLS) for missiles. Keeping the hull cost low would mean the SM-3 missiles would be worth more than the ship, as it should be. Other benefits would be extremely low manning, which could allow for crew swapping, keeping the ship on station for as long as possible.

[brian eiland]

....Back to those design concept drawings by Humphrey’s. I can fully imagine a scaled-down version of this tri-hull design, in the 65-70 foot range,....
I recently ran across some wonderful computer generated illustrations by Mike Kagan. I asked him if he might generate a few for the smaller versions of the tri-hull kite-assisted vessel. Here is one of those versions.

Go to this page for a few more rendenings on that vessel idea:
http://www.yachtforums.com/forums/yacht-renderings-plans/14713-mike-kajan-yacht-designs-ii-7.html

Its time for some yachtsman to start planning for a vessel like this.

[Boston]

if they only had that thing is say a 35hp unit

cheap

[ingovoegler]

As I just now registered, first a short introduction of myself:
I have been following this thread since, 1 1/2 years back, I had an idea for a kite drive unit, which, I believe, might be a big step forward on the way to making kite power a reasonable alternative to conventional sails. Since that time I have been working on prototypes and a first workable one is complete, see this clip:

http://www.youtube.com/watch?v=yVwZRZYkzzE

a second one, simpler, lighter and faster, is under construction and will be ready soon.

I can't wait for your opinions, and will be happy to answer questions about my project

Ingo


P.S. If my English is incorrect, please forgive, I'm German

[Boston]

hey thats pretty slick
nice job

B

PS
your English is fine

[sigurd]

Ingo, that is a sweet system. I had something similar in mind years back, but it used T foils instead of the straight ones you have, both for vertical lift and to immerse the foil giving lateral lift, in order to reduce ventilation. It would have a surface piercing V on the stern.

Make sure you are prepared to get flooded from the rear when the kite lifts the bow.

Are you using a reel? There are a couple of kite reels in this archive, from Cristopha and me.

[Doug Lord]

As I just now registered, first a short introduction of myself:
I have been following this thread since, 1 1/2 years back, I had an idea for a kite drive unit, which, I believe, might be a big step forward on the way to making kite power a reasonable alternative to conventional sails. Since that time I have been working on prototypes and a first workable one is complete, see this clip:

http://www.youtube.com/watch?v=yVwZRZYkzzE

a second one, simpler, lighter and faster, is under construction and will be ready soon.

I can't wait for your opinions, and will be happy to answer questions about my project

Ingo


P.S. If my English is incorrect, please forgive, I'm German
==============
Ingo, what a neat idea-congratulations! (Nice music and location, too) It appears that the foil will provide lateral resistance and also develop substantial downforce-correct? Very innovative solution you have there-good luck.

[ingovoegler]

Ingo, that is a sweet system. I had something similar in mind years back, but it used T foils instead of the straight ones you have, both for vertical lift and to immerse the foil giving lateral lift, in order to reduce ventilation. It would have a surface piercing V on the stern.

Make sure you are prepared to get flooded from the rear when the kite lifts the bow.

Are you using a reel? There are a couple of kite reels in this archive, from Cristopha and me.

Sigurd,

in my first (functional) prototype, the one sailing in Goa, I had used a reel with 4x60m of Dyneema Lines, to prevent damage or the bow to be lifted it had a slipping clutch (build myself out of a scooters drum brake), I powered it by bycycle pedals. It took a few weeks time and a lot of effort, to get it reeling in all lines simultaneously enough, to ensure smooth operation of the Kite, 0,1% of 60m=6cm being the highest acceptable difference between the main lines. However, the reel not being saltwater resistant and quite big and heavy, for my second and third prototype http://www.youtube.com/watch?v=ruBQ1CM_VUA , I skipped the reel and using the original Kitesurfing bar instead, the lines being redirected through a ring at the tip of the push/pull rod. This makes the construction much simpler, the risk of the boat being lifted or damage to kite, lines or boat I am trying to avoid by a predetermined breaking point where the bar is fixed to the boat. I am still working on a perfect solution for this(the redirecting ring has to be released simultaneously for the system to work).
I have experienced the flooding of the boat of which you warned me already twice on baltic sea and am not very keen to repeat this experience.
Without the reel, the whole thing is simple and light enough, to be build within a few days and can be fixed to almost any boat, I even sailed a small sit-on-top-kayak with 21sqm of Kite, haven't got much proof(http://www.youtube.com/watch?v=_JmrCF-8YBU), but anyone could imagine that this is a real high performance sailcraft, I sailed upwind at a good angle(est 45deg) at hull speed(~4knts) and easily planning on all other courses (I estimate to have sailed as fast as the wind, which was about 8 knts).
Unfortunately in Goa, where I usually live, is Monsoon now and sailing impossible due to high seas, had thus been to Germany for trying out the dinghy, which was (uncrewed) weighing less than a third of the first prototype(~500kg/~130kg) and performing obviously not as good as the kayak but still very fast(gps showed max. 8,6kts at around 12knts of wind without trying for a speed record)
As there won't be good conditions for sailing during the next 6 months here in Goa, I most probably will go back to Germany soon for further trials(being quite addicted to kitesailing for now).

Ingo

P.S. I had read through this full thread after I got the idea for my invention and thus knew that you had experimented with kiteboating as well, was (and still am) wondering, why you had stopped it.

[ingovoegler]

==============
Ingo, what a neat idea-congratulations! (Nice music and location, too) It appears that the foil will provide lateral resistance and also develop substantial downforce-correct? Very innovative solution you have there-good luck.

Doug Lord,

the nice location is where I have been living for the past five years, one of the few drawbacks is, that sufficient wind for (at least kite-)sailing is very rare here. The foil provides mainly lateral resistance, the downforce is negligible, would have to place it at a different angle, but a certain lift from the kite is well appreciated, as it makes the boat lighter and by sitting more towards the bow I counter it enough, to prevent problems. As you seem to be enthusiastic about foils, as well as kiteboats, you will certainly be very interested in the kiteboat project of Don Montague, who has among other hull configurations with foils, reanimated a bigger version of the hobie trifoiler. In case you didn't know it already here is the linkhttp://project.kiteboat.com/

Ingo

[ingovoegler]

hey thats pretty slick
nice job

B

PS
your English is fine


Boston,

thanks for compliments, my (written) English is fine due to the use of a dictionary, spoken it would be a different story. I have further simplified my invention, second (http://www.youtube.com/watch?v=_JmrCF-8YBU) and third (http://www.youtube.com/watch?v=yVwZRZYkzzE) prototype have been quite easy and fast to build, and due to heavily reduced weight are performing much better.
If anyone, be it Skysails, Don Montague (http://project.kiteboat.com/) or anybody else, solved the launching(not that big of a problem in my opinion) and recovery(!!) problem in a way, that would allow comfortable use in smaller and medium sized yachts at an affordable price, I would bet any money that kiteboats would soon replace conventional sailboats, offering the opportunity to use much bigger sail area on completely heeling free and capsize-safe boats. I am, however, not so sure that it is going to happen soon.

Ingo

[sigurd]

not stopped, at all, but apparently I am too lazy to get anything done. I've broken all daggerboards I have used, so I need to get me a proper carbon one. The tornado (20ft cat) was too heavy for upwind work with my kites, I am going to experiment with dual kites until I can afford a 21m flysurfer speed. Right this morning I have started patching up a kayak that was sawed in two, it is going to be a proa (goes backwards and forwards instead of on starboard/port tack) with the daggerboard in an outrigger float.

I have found that a meter or so difference in kiteline length is ok, when they are out they get to the same length. I had the rear lines running through a pair of lightweight pulleys (took me a while to find pulleys that would not seize on the thin kitelines, and q-power-lines help too), which in turn are attached to the control bar on adjustible length (0-0.5m with a prussik knot) ropes. When the lines were out I just bypassed the pulleys by hooking the rear lines directly to the bar.

I had a great time getting thrown out of the Europe dinghy, holding onto some rope and the control bar, trying to keep the kite flying while crawling back inside what was now a bathtub. One of the funny things with kitesailing is planing from zero knots and up :) .

I am attaching a sketch of the attachment system that I'll try on the proa kajak, which solves for pitch and yaw to some extent.
And a sketch of my kite reel - I forgot to draw the ring (padeye) that guides the lines onto the spool but you'll have to imagine it.

[sigurd]

And on the subject of non-heeling kite systems, Peter Lynn has invented a neat system that aligns the kite pull with the center of lateral resistance of a fixed daggerboard. He used it on a long skinny monohull. IIRC the daggerboard was later replaced with two through hull rudders. It is documented somewhere in his online newsletter I think.

I have attached a sketch of the principle - hope it can be understood.

[sigurd]

For safety release, all my kites needs to be held in one line only in order to depower. What I did is to stop one of the lines by attaching a steel ring at its end, which would not be able to pass through the line guide ring (padeye). The drawing only shows the front lines, for clarity.
The orange rope is 10m longer than the blue one. So if I need full depower I can let out the orange while the blue is held. Always keep a knife handy - once I caught a motor boat with my kite. It was too little wind to keep it flying.

PS: Launching issues depend a bit on the wind and type of kite. If there is little wind it can be good to launch a dry kite, otherwise I just inflate it somewhat and let it drift to leeward. As my boat was so light I used a sea anchor to let the kite drift faster than me. I could do this without a reel too. For dry launching I used a few different pole systems to hoist the kite, let it inflate and fly while I reeled out. One of them was the stock Europe dinghy mast, worked ok but it was in the wrong place so gybing got more complicated. I made an attachment in the middle of the leading edge of the kite to hoist. Then I used two telescopic fishing poles mounted like a V on the stern, with the kite spanning between them. Worked ok but one of them broke. So lastly I used just one telescoping pole on the stern and it worked ok too. With a motor, light wind launching should be much easier. Otherwise, I imagine hoisting the kite like a spinnaker to gain apparent wind will help.

Edit: here is a neat launch system too, for different application: http://www.youtube.com/watch?v=jHeSKFW5xuY&NR=1

edit: very messy pic of the reel: http://www.boatdesign.net/forums/attachments/sailboats/7672d1150779259-kite-dinghy-cimg1866.jpg

[brian eiland]

Control unit for energy-generating kite aces LabVIEW tests

KITEnergy is a revolutionary technology that converts higher-altitude wind energy (between 200 and 1,000 m above the ground), with respect to the actual wind turbines, into electricity. High-altitude winds are stronger and more constant. Because the generated power grows with the cube of wind speed, it can achieve a significant increase of power production.

To exploit high-altitude wind, KITEnergy uses wings (or power kites) linked to the ground by two cables. The flight of the wings is tracked using onboard wireless instrumentation driven by an automatic control unit that can differentially pull the lines to influence the wing motion. Electricity is generated at ground level by converting the traction forces acting on the lines into electrical power, using suitable rotating mechanisms and electric generators. Recent studies – including theoretical analyses, numerical simulations, and experimental tests – carried out at the Politecnico di Torino, indicate that KITEnergy technology can produce large amounts of renewable energy that is available practically everywhere in the world at a lower cost than fossil fuels; thus, it does not require public incentives for its diffusion, a difference from the available renewable energy technologies.

....more here:
http://www.designfax.net/enews/20110802/feature1.php (http://www.designfax.net/enews/20110802/feature1.php)

[Boston]

Hey Ingo

what if you only launched and recovered the kite off the mast and had a system that held the moment arm much lower on the boat, reducing heel. Say a track that ran around the deck and the lead line could attack there instead of so far off the deck, you might be able to reduce slip and heel some and get way better performance

just an idea

cheers
B

[ingovoegler]

Hey Ingo

what if you only launched and recovered the kite off the mast and had a system that held the moment arm much lower on the boat, reducing heel. Say a track that ran around the deck and the lead line could attack there instead of so far off the deck, you might be able to reduce slip and heel some and get way better performance

just an idea

cheers
B

Hey Boston,

there isn't any heel in my system, as the foils and the moment arms are pivotable around a longitudinal axis, they are balancing out in front of the boat, only the driving and lifting forces, which both are appreciated are transmitted to the boat.59465 As the foils are asymmetric, they are highly effective(they seem to be to me at least), and I am absolutely satisfied with the performance, at least of my latest prototypes, the first one was just to heavy.

In the first prototype http://www.youtube.com/watch?v=yVwZRZYkzzE I actually had chosen to keep the moment arms quiet long, because I had thought of launching the kite from them; however launching prove to be quiet easy, as long as wind was strong enough(~8knts), by just prefilling the kite on deck (I am using a foil kite, prefilling by holding it in the wind)59466 and letting it drift away from the boat, then it easily would launch, whenever I want it to do so(by shortening the front lines). Even recovering the (21sqm-) Kite is manageable, however I couldn't launch it again until I took it to shore, untangled the bridle, dried and folded the kite in a predefined way (takes, on my terrace, around 10 to 15minutes for untangling and folding plus 30 to 45min, in Goan sun, for drying).
This procedure, though it is perfectly acceptable for myself on my small dinghy, wouldn't be practicable on bigger boats/yachts and with bigger kites, and as I feel unable to solve this problem by myself, I can only hope for others to do so.

Ingo

[ingovoegler]

I am attaching a sketch of the attachment system that I'll try on the proa kajak, which solves for pitch and yaw to some extent.


Hey Sigurd,

there shouldn't be any yaw in your proa, it should even steer itself, without a rudder, as the kite attachment point is far enough from the dagger board. Kite pull and resisting force of the dagger board will always aim to keep in the same line and thus keep the boat on track(on a fixed angle towards the kite pull), so you can steer by only depowering(for sailing upwind)/powering/sinussing/figure-eighting(broad reach) the kite.
By moving the kite attachment point along the hull, the Angle of Attack of hull + dagger board will change. Proa will stop(resp. drift slowly sideways), when attachment point is in the center/vertical on dagger board and will accelerate, when moving attachment point towards bow/stern.
I am wondering if you where using the same effect on the Europe dinghy or if you where using a rudder on that(with foot steering or helmsman?).

About my reel: As also mentioned somewhere by Peter Lynn, line drag is heavily reducing upwind performance, so it is beneficial, to keep lines short while sailing close to the wind, but on other courses long lines are giving better performance, that's why I tried to have consistent line lengths for all four lines when fully rolled out as well when short. When the frontlines where of considerable different length, the kite would perform well only on one side, after jibing I couldn't go to windward anymore.
Now however after having skipped the reel and just using the original kitesurfing bar with 21m lines, I am quite okay with the upwind performance.

For starting the kite in light winds, as you did, I used a drift anchor, when the wind was to light for the wet kite to easily start, I usually couldn't keep it in the air for long anyway.

Ingo

[sigurd]

I used rudder with foot strap on tiller.

[sabahcat]

Video of a 40ft powercat from 2004 using Kitesail/traction kite with no mast in evidence.

How is it done?

http://www.youtube.com/watch?v=HD6XMvPCVdg&context=C3e5c905ADOEgsToPDskLtAaAiqHXb1ZV6x6ptxY1l


I coloured the sheets for clarity, they were barely visible before.
http://img62.imageshack.us/img62/9650/w2963.jpg

[brian eiland]

Check out these videos,...and website :!:

http://project.kiteboat.com/video

[Boston]

hey thats really slick Brian

Two thumbs up

[4wings]

Check out these videos,...and website :!:

http://project.kiteboat.com/video

yup they actually solved the problem this thread is discussing for the last 5 years ...