New Age Trawler/Motorsailer; Kite assisted PowerYacht

[brian eiland]

New Age Trawler/Motorsailer; Kite-assisted PowerYacht

I’ve come to a realization in this current age of escalating fuel prices, that there are two forms of pleasure yachts that are likely to survive the energy crunch, and even possibly flourish…the motorsailer and the kite-assisted power vessel.*

There’s been much written about motorsailers, including my preference for the multihull form of that gender…basically a more easily driven hull for both the motor and sail power to act upon…greater range, more economy, better performance.

Now we come to a new era, and again it’s the ‘fringe’ sailing youngsters that show us another way…kite sailing. You may have witnessed some of this activity out on the bays and the lakes where the windsurfers use to play. Check out this ‘YouTube’ clip,
“I Can Fly”,http://www.youtube.com/watch?v=lkyOhyocw2E
There is power in that wind to drive our vessels, and methods to extract it other than conventional vertical mast sailing rigs. Para-foil kites can produce very considerable power, and can be controlled in flight as the military discovered long ago. Now if we get those kites up into the better winds aloft, we can tap into that more consistent energy than exist at the sea level.

Two companies that have been quite active in the promotion of driving ships with kite power are:
1) KiteShip: http://www.kiteship.com/
2) SkySails: http://www.skysails.info/index.php?L=1

At present the Skysails group appears the more advanced of the two, particularly when you consider their single-line tethering, and computer flying of the kite. They have an automated stowage and deployment scheme as well. These parafoil kites can even fly upwind to certain degrees. A review of the websites is quite interesting. But they are not the only game in town, there is a lot of military interest in precision flying kites as well; ie, Atair Aerospace, http://www.atairaerospace.com/

How might this kite business affect the yachting business? It goes back to idea of a motorsailer, or phrased differently, a ‘wind-assisted power vessel’. If we can optimize the economy of the power vessel, as the trawler concept seeks to accomplish, and then add ‘sail’ assistance, we have a recipe for a ‘future class of new-age trawlers’ that can be quite economical to operate, and have a great range. I believe this could be a very viable alternative yachtform for our new fuel future.

Humphrey’s yacht design is very big on this idea as well. Attached is their tentative proposal for a 40M SkySail MotorYacht. They’ve termed it a SkySail-supplimented MotorYacht, "The use of the word ‘supplemental’ is chosen carefully. While we expect this family of boats to be able to ‘sail’ efficiently under SkySail, we foresee that fundamentally the boats have to be very efficient and seakindly motoryachts, and in this respect the common denominator for efficiently under both forms of motive power is low hull resistance. Thus our work on this generic set has evolved towards slender body hulls that derive stability from wavepiercing outriggers….they are in effect trimaran derivatives, which will have long rang capability under engine, not to mention the ‘free’ miles under SkySail."

I have been following some of the ‘slender ship’ technology as it has cross-over potential with multihull technologies. For a few references, visit these websites, and see a few of the attachments I’ve provided:
1) Worlds Largest Powered Trimaran : http://www.trimaran.dera.gov.uk/
2) White Rabbit tri : http://www.yachtforums.com/forums/13292-post2.html
http://yachts.monacoeye.com/yachtsbysize/pages/whiterabbit01.html
3) Very Slender Vessel, VSV : http://www.specialboatservice.co.uk/vsv.htm
http://www.globalsecurity.org/military/systems/ship/vsv.htm
4) Cable & Wireless Trimaran :
http://www.solarnavigator.net/history/cable_and_wireless.htm
5) Catamaran Vessels : Lets not forget the catamaran hullform, they are in fact slender ships as well. As I wrote in a recent press release, “Our next design (coming soon) will be an adaptation of this new motorsailing catamaran design into a kite-assisted power cat. We will exclude the Dynarig sailing rig and substitute a SkySail kite rig. Next will be an entirely new hull design making use of the kite-sail concept”


Back to those design concept drawings by Humphrey’s (attached PDF). I can fully imagine a scaled-down version of this tri-hull design, in the 65-70 foot range, with a wonderful rear ‘swim’ platform deck incorporating a sportfishing arrangement and/or a Scuba diving platform. Just inside could be a tender stowage as shown; or rather a complete diving & fish tackle facility. The tenders could then stow up on rear deck, or one forward, one aft.

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.
1) Volvo IPS : http://www.yachtforums.com/forums/yacht-reviews-feature-stories/7467-world-debut-volvo-pentas-new-ips-750-850-a.html (http://www.yachtforums.com/forums/yacht-reviews-feature-stories/7467-world-debut-volvo-pentas-new-ips-750-850-a.html)
2) Rim Drive : http://www.yachtforums.com/forums/technical-discussion/3961-rim-driven-propellers.html

Supplementing this single main engine would be a single DC diesel/electric power unit to provide for:
1) Ships electrical requirements
2) Slow speed operation by electric (wing) motor belted to main prop shaft
3) Maneuvering thrusters as required depending upon azimuth capabilities of main prop.

The entire ship would be powered by only two engines, basically sized to provide:
1) Full main diesel power, unimpeded by interceding diesel/electric conversion
2) Slow speed operation and ship’s systems via the smaller diesel/electric unit
3) ‘Twin power’ emergency backup as either engine can run all gear
This configuration more ideally meets the latest thinking for the new diesel/electric DC technologies onboard smaller vessels. Alternatively, two identical diesel/electric plants might be sized such that in combination they would supply the max power required of the vessel, and half power for lesser times.

Only two engines and no conventional sailing rig should make this a more affordable vessel, both in construction, in maintenance, and in operation. However the SkySail kite arrangement will probably more than offset the conventional sailing rig in cost. Possibly a less expensive alternative to this ‘brand name’, with less computerization could be found (no integrated weather/navigation features, etc). Light-weight construction would be desirable but not necessary. Third world hull construction materials are a possibility.

I’ll call it a KiteSail Motorsailer for now.
....comments, suggestions


* I must include a disclaimer that many ‘superyachts’ will also survive, as there will always be some people with unlimited funds to do whatever strikes their fancy regardless of price of construction and operating expenses.

PS: I must give credit to Guillermo who brought this to my attention, "Brian: You should try this also for your big game fishing catamaran" at posting #285 (http://www.boatdesign.net/forums/showpost.php?p=130326&postcount=285)

[Munter]

I think one of the stumbling blocks that may impact on the usefulness of the kite technology (which as a kite surfer I'm a big fan of), is the utilization factor that will be achieved in practice. How many superyacht owners are going to be happy to schedule their journeys in to match the conditions in which the kite will effectively assist? I fear that when scheduling constraints are applied to the movements of the ship the kite will only see limited use.

[brian eiland]

(which as a kite surfer I'm a big fan of)
As a kite surfer I imagine you seek out the maximum fun (speed), and rarely
experiment with how close you might be able to go to windward, or other sailing angles?? Correct me if I'm wrong.

At this time there is virtually no organized racing in these kite (vessels), so very little experimentation in all of possibilities that might exist with these 'sailing' vessels? Beach type catamarans and windsurfers eventually developed a lot of head-to-head racing venues that further developed the capabilities of their sailing potential. I believe there is yet a lot to discover here in the 'sailing potential' of these kites.



How many superyacht owners are going to be happy to schedule their journeys in to match the conditions in which the kite will effectively assist? I fear that when scheduling constraints are applied to the movements of the ship the kite will only see limited use.
Granted the 'superyacht' owner will be less concerned with fuel bills and more with speed, so his use of kite-assist will likely be small, if at all. It's the gentlemen who sought out the trawler yacht rather than the fast power yacht that will be attracted to this alternative. And it could well be the sailor who grew a little old for the rigors of sail handling, and thus began looking at the trawler for its cruising attributes, that could be attracted to this 'new age' trawler/kitesail motoryacht.

SkySails is fervently seeking to maximize the usable conditions that the kite can assist in propulsion, in order to sell the concept to the shipping industry. So advancements should come more quickly. Their website is pretty interesting.

[Munter]

Getting upwind is an important part of kiting. Its how you buy the room to make big jumps which inevitably cost you 10's of meters downwind loss.
The upwind angles aren't as high as a racing yacht but they are still respectable.

One thing that would make that upwind performance difficult to repeat with a motor yacht is the loss of the reflex like control that the rider has when the bar is directly in his hands and the board directly on his feet. A kiter is constantly playing a dynamic balancing game controling kite line pressure, kite line angle and the angle of the board in the water (sideslip resistance). If this balance isn't maintained you can end up getting dragged downwind or falling back into the water. Replicating the instantaneous control of all those variables on a larger structure would be a complex task! As I understand it the kites were predonminantly intended to help with downwind sailing which I think would be an easier control task.

I'd love to see kite-ships going upwind but I think they have a fair bit of development to go before it can be done.

[brian eiland]

.. the loss of the reflex like control that the rider has when the bar is directly in his hands and the board directly on his feet. A kiter is constantly playing a dynamic balancing game controling kite line pressure, kite line angle and the angle of the board in the water (sideslip resistance). If this balance isn't maintained you can end up getting dragged downwind or falling back into the water. Replicating the instantaneous control of all those variables on a larger structure would be a complex task!
Good points Munter

[Fanie]

If you have two pipes some distance from one another and some distance upwards (the outlet ends) these kites may well be easy enough to bring in, let out and may even prevent ropes from twqisting up.

If you have the kite in, the whole kite is dragged into one pipe, so between the two pipes is only a rope. To let the kite sail out, pull so the kite is about midway between the two pipes, allowing the wind to catch and take it out. The pipes a distace from one another would prevent the ropes from twisting but will depend how far the kite is let out. To bring in is simply a matter of winching it in, then winch one side only so it is out of the wind in the one pipe. Just an idea.

[Guillermo]

The SkySails system is based on the kite constantly flying in dynamic mode (figure of 8), this to generate dynamic stability and increased power.

The kites are able to develope up to 2HP per sqm under the adequate conditions and, as they fly around 110º off the wind, you can even beat to winward with them (although less efficiently, of course). A 55º wind angle off the bow is possible.

For the time being the system is relatively expensive, but probably price will come down with increasing production. I've been investigating applicability to fishing vessels (30 to 70 m trawlers) and the system pays back itself in around 3 years (We did detailed studies of real life conditions for three of such vessels, with the collaboration of their owners and captains). It can be mounted without much fuss in around a week at an existing fishing vessel's forward deck, after the proper detailed engineering study of feasibility, of course. We are trying to mount the system aboard one of such units and test it, not only for free running, but also for when under trawling operations, which is the most important aspect. The bad news is fishing-vessels owners are not easy to convince....;)

Cheers.

[brian eiland]

...couple of short videos
http://youtube.com/watch?v=a8qeKslrqeY


...you've got to wish these young guys luck...they've got a tough sale to those big guys, even though it looks very promising
http://youtube.com/watch?v=2umdKznDkfA

[Guillermo]

What about this one?
http://www.youtube.com/watch?v=qnACybMhPs4&NR=1
More here:
http://www.metacafe.com/watch/766538/kiteboat_hawaii/
The idea is spreading....Brian, big game kite-fishing at last? :)
Following Pericles wake, I've proposed a Round the World Race using only Kites as means of propulsion. Wouldn't it be very nice if some of the manufactures/inventors 'pick up the glove' and launch such a project?

Cheers.

[Pericles]

Guillermo,

All this good PR started me looking for smaller versions for your vessel.

http://www.waterbird.co.uk/parasails.php

http://www.flexifoil.com/

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

http://en.wikipedia.org/wiki/Man-lifting_kite

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

Oh dear, I'm off on another flight of fancy. :( :(

What about this?

http://www.kitegen.com/pdf/ACCNewYork2007.pdf http://www.kitegen.com/index_en.html



Perry

[brian eiland]

What about this one?
http://www.youtube.com/watch?v=qnACybMhPs4&NR=1
More here:
http://www.metacafe.com/watch/766538/kiteboat_hawaii/
The idea is spreading....Brian, big game kite-fishing at last? :)
Following Pericles wake, I've proposed a Round the World Race using only Kites as means of propulsion. Wouldn't it be very nice if some of the manufactures/inventors 'pick up the glove' and launch such a project?

Cheers.
Good find Guillermo...that video.
I haven't had time to look thru those references of Pericles yet. I'm sure somethings interesting

Brian

[Guillermo]

What about this?
http://www.kitegen.com/pdf/ACCNewYork2007.pdf http://www.kitegen.com/index_en.html
Interesting....although somewhat complicated :)

[brian eiland]

Here is a nice launching photo of the SkySails unit:

...and another video from the company,
http://80.252.99.206%20/streamingfarm/Skysails/Beaufort_Explenationvideo_512k.wmv

[brian eiland]

Catamaran Vessels : Lets not forget the catamaran hullform, they are in fact slender ships as well. As I wrote in a recent press release, “Our next design (coming soon) will be an adaptation of this new motorsailing catamaran design into a kite-assisted power cat. We will exclude the Dynarig sailing rig and substitute a SkySail kite rig. ”

Sorry for the rather rough sketch at the moment, but here is the kite-assisted power cat at the moment of launch.

[Pericles]

Brian,

I truly hope this concept is taken up, because you have pioneered many really good ideas.

Best regards,

Pericles

[masalai]

From my observations of the joy-riders in the "surf" at the mouth of the Maroochy River I must solidly agree with Munter, Too many control issues to be resolved as yet for significant upwind work.

Brian I hope your inventive attitude and developments continue & you can resolve the upwind issues for say a 40ft cat! I would like that as an alternative motive force, else the "hitch-hiker" form will have to suffice for me. Thanks.

[Guillermo]

How many sqm of kite would you say you'd need for your foreseen speed, asuming 1kW/sqm as mean power?

[masalai]

Guillermo, I hope that Brian Eiland can answer that as I have only got to the "its interesting stage & what are the control/performance issues". . The "joy riders" seem to have up to 15 sq metres....?

[brian eiland]

Brian, I truly hope this concept is taken up, because you have pioneered many really good ideas.

Best regards, Pericles
The credit should go to Guillermo who brought it to my attention per my notation in the originally posting: "Brian: You should try this also for your big game fishing catamaran" at posting #285

I just took up the banner, and hope to run with it.


How many sqm of kite would you say you'd need for your foreseen speed, asuming 1kW/sqm as mean power?
I hope that Brian Eiland can answer that as I have only got to the "its interesting stage & what are the control/performance issues". . The "joy riders" seem to have up to 15 sq metres....?
Sorry guys, I do not know this sqm figure yet myself. I would assume there will be a considerable range of possibilties depending upon the clients desire to split the wind verses diesel capabilities, and his desire to fly the kite in more complicated patterns, or in more demanding conditions...both more costly.

The basic catamaran platform is extremely stable to carry a relatively large kite without concern for lift-off or capsize, and the configuration of the basic ship might well be the same for a smaller or larger kite. So the client might wish to play it conservative to start with, and only need to increase the kite size in order to upgrade, without a redesign or rebuild of the vessel.

I'm presently looking at an existing production 50' catamaran that might well lend itself to the initial vessel, or even an existing used vessel. Just need that bold adventuresome client/sailor willing to experiment with his new power cat

[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.

[masalai]

Thank you sir, I will keep my eye on developments in this thread.

[mark424x]

I wonder if anyone could comment on the ability to get any upwind VMG out of such a kite rig on a power boat hull. I can't image you'd get much dynamic lift from a cruiser like a hatteras/defever/navigator, but I wonder if you were in a displacement power catamaran Tennant/PDQ/MaineCat or maybe even a traditional trawler, DDuck, if you'd get enough lift to get to 60 deg to windward.

In addition to added power, the additional roll stability would be an added value.

Here on the US West coast, you could pop your kite in Alaska and ride it south to Panama. Even the sailboats mostly power going north.

[masalai]

mark424x,
Hi All I can suggest is you try it and be a net hero by posting info.... Do they have those kite boarders getting air when there is a nice breeze and a bit of chop from which to launch? they are about 15m2 for the big light air wings which you could trial on your next cruise - If not as good as you would like can be sold to a wind-surfer in California etc

All I can do is wish you well and every success...

[brian eiland]

I wonder if anyone could comment on the ability to get any upwind VMG out of such a kite rig on a power boat hull. I can't image you'd get much dynamic lift from a cruiser like a hatteras/defever/navigator, but I wonder if you were in a displacement power catamaran Tennant/PDQ/MaineCat or maybe even a traditional trawler, DDuck, if you'd get enough lift to get to 60 deg to windward.

Here on the US West coast, you could pop your kite in Alaska and ride it south to Panama. Even the sailboats mostly power going north.
Did you have a look here:
http://www.skysails.info/fileadmin/user_upload/Pressedownload/Dokumente/EN_Technology_Information.pdf
...specifically page 3

[brian eiland]

One thing that would make that upwind performance difficult to repeat with a motor yacht is the loss of the reflex like control that the rider has when the bar is directly in his hands and the board directly on his feet. A kiter is constantly playing a dynamic balancing game controling kite line pressure, kite line angle and the angle of the board in the water (sideslip resistance). If this balance isn't maintained you can end up getting dragged downwind or falling back into the water. Replicating the instantaneous control of all those variables on a larger structure would be a complex task! As I understand it the kites were predonminantly intended to help with downwind sailing which I think would be an easier control task.

I'd love to see kite-ships going upwind but I think they have a fair bit of development to go before it can be done.
Maybe time to re-review this YouTube reference that Guillermo brought to us back in posting #9

http://www.youtube.com/watch?v=qnACybMhPs4&NR=1

http://www.kiteforsail.com (http://www.kiteforsail.com/)/

[mark424x]

Did you have a look here:
http://www.skysails.info/fileadmin/user_upload/Pressedownload/Dokumente/EN_Technology_Information.pdf
...specifically page 3

Thanks, yes. As I understand it, the only way to get close to a beam reach (or higher) is to have hydrodynamic lift from a keel or the underbody shape of the hull. My assumption was that you'd have to modify a power monohull to get any appreciable lift, but was hoping that a displacement power cat might have enough lift from the slender hulls. But that is a complete intuitive guess.

[masalai]

Thanks Brian, advances are being made - so good to see

[Tad]

So the Beluga SkySails has now crossed the Atlantic but they are not releasing any information on performance until its "properly evaluated"??? This encourages my skepticism. They claim a 3-5 year payback period for the system, which costs approximately half a million euros. They do not state what is included in that cost. Does it include financing cost? Additional insurance? Increased manning certification? What is the maintenance and down time really going to amount to? If the ship costs more to purchase and operate, shipping costs go up, is that included in their costing?

What does the Beluga SkySails carry anyway? Why not totally eliminate the need for that transportation? Would that not be even more environmentally friendly?

[brian eiland]

Tad,
I don't think I would be in a GREAT rush to release this raw data yet if it were me...particularly with the clientel they are appealing too...the big commercial shipping guys.

One wrong move and you could turn them off to continued and future developments. I've seen a few advanced ideas fail as a result of premature hype.

Why not totally eliminate the need for that transportation
Are you suggesting that all small ships such as inter-island traders be scrapped in favor of big ships??

I found it interesting that the remains of the racing trimaran Groupama were being shipped back to France from New Zealand on a relatively small ship carring fresh produce to Holland I believe.

[Munter]

Tad - minimisaiton is a good idea but it should be done in parrallel with efficiency improving technologies. Some things will still need to be transported.
I wonder if oil at $110/b will be enough to change the status quo?

[Tad]

Tad,
I've seen a few advanced ideas fail as a result of premature hype.


If it was me, and if the voyage was a spectacular success, or even made predictions, I would be getting the story out....asap. The fact is that almost every attempt to revive commercial sail in the past 40 years has ended in failure. The only successes I can think of are the "cattlemarans" of the Caribbean tourist industry. The larger the project the bigger the failure.

I'm suggesting we eliminate large vessels and transoceanic freight of useless consumer goods. The earth and human society cannot sustain it. Local production and transportation lends itself to small units which spread the load and the wealth around, but keep it local. I'm taking about 50-100 miles max.

I think putting kites on oil tankers is fooling yourself that you have done something good. Eliminate the need for that oil to be processed, shipped, stored, distributed, sold several times over, and then burnt, and perhaps you really have done something good.

I have carried freight under sail, done offshore commercial fishing under sail, even carried livestock under sail. The schedule is always there, and its almost impossible to ignore. There are numerous external forces at work, the wind, the tide, connections, crew changes, it's endless. What will happen when the Skipper of Beluga SkySails phones head office...."Forget the schedule guys, we're saving fuel". Head office will kindly remind him that there is a schedule, and he'd best keep to it.

[Guillermo]

Tad,
Shipping is the most efficient transport system in terms of energy used per ton/mile carried. 800 times less than the airplane. It is also the cheapest system in terms of total cost per ton/mile. Better than trucks and even trains.
Land and air transport have also several other drawbacks, both in enviromental costs, investments needed and infrastructures saturation.
Should we ban airplanes, trucks and trains? ;)

Some interesting info:
http://www.uofaweb.ualberta.ca/ipe//pdfs/TransportPaper-Cappato_Capocaccia.pdf
http://www.epolitix.com/EN/Forums/Sea+and+Water/cf53bb1d-5e2b-4798-bb00-8336776faed2.htm
http://www.dft.gov.uk/about/strategy/transportstrategy/hmtlsustaintranssys

Interesting reading:
Jeffrey Samuel Barkin. “The Counterintuitive Relationship Between Globalization and Climate Change.” Global Environmental Politics, vol. 3, #3 (August 2003), pp. 8-13. Abstract:
"Scholars and activists are concerned, sometimes simultaneously, with mitigation of anthropogenic climate change and the environmental effects of globalization. Many analysts argue that a solution to both problems is localization; increasing the costs of transportation should increase the cost of long-distance transportation, making local and regional exchange economically relatively more efficient. The argument here, however, is that dealing with climate change will have the effect of reinforcing patterns of economic globalization, at the expense of patterns of economic nationalization and continentalization. Transportation by sea has historically been, and continues to be, more fuel-efficient than transportation by land. Limiting anthropogenic carbon emissions in transportation therefore favors sea transport over land transport. Historically, patterns of trade favored global seaborne trade routes over trade within land-based regions. The model to look in understanding the effect of action on climate change on global trade pattens, therefore, is not the future proposed by the localists, it is at historical patterns."

Cheers.

[Guillermo]

http://www.skysails.info/index.php?id=64&L=1&tx_ttnews[tt_news]=104&tx_ttnews[backPid]=6&cHash=db100ad2b6

Hamburg / Mo-I-Rana, 14 March 2008. “We can once again actually ‘sail’ with cargo ships, thus opening a new chapter in the history of commercial shipping,“ was the verdict from Captain Lutz Heldt following his return from the nearly two-month maiden voyage of the multi-purpose heavy-lift project carrier “Beluga SkySails”, which sailed from Germany to Venezuela, the United States and Norway. In even moderate winds, the first flights of an initial 160-square-meter towing kite propulsion system from the Hamburg-based manufacturer SkySails demonstrated how this innovative auxiliary propulsion system was able to substitute for 20% of the engine’s power. “With that we impressively validated the original expectations we had for the system“, was how SkySails managing director Stephan Wrage (35) assessed the first practical trials aboard the Beluga ship. “In the future, depending on the route and weather conditions, we’ll be able to post fuel savings of between 10% and 35% using wind power.” The “Beluga SkySails” set sail to Venezuela from Bremen on 22 January and reached the Norwegian port of Mo-I-Rana on 13 March 2008 after travelling a total of 11,952 nautical miles. The testing of the SkySails-System on board the ship newbuilding MV “Beluga SkySails” to be equipped with this innovative technology is being co-funded with some 1.2 million euros as part of the European Union’s “LIFE” program.

“The MV ´Beluga SkySails’ maiden voyage is proof in motion of a new kind of hybrid drive on the water that simultaneously reduces both voyage costs and climate-damaging emissions,“ said Niels Stolberg (47), the president and CEO of the Bremen-based project and heavy-lift cargo shipping company Beluga Shipping.

“The initial focus during the first half of what is set to be an approximately 12-months pilot testing phase aboard the “Beluga SkySails” is on calibration work and adjustments to stabilize the towing kite propulsion,” reported Stephan Brabeck (46), the technical director of SkySails, adding how “in the second half the flight times will be extended and the performance perfected.” On numerous days during the maiden voyage the system was put in action for periods of between a few minutes and up to eight hours. During that time the SkySails-System pulled the ship with up to 5 tons of power at force 5 winds, which when compared to the engine output represents a relief of more than 20%. Projected onto an entire day, this performance by the “Beluga SkySails” represents savings of about 2.5 tons of fuel and more than $1,000 a day.

Captain Lutz Heldt (57) is impressed with the first flights of the 160 square-meter SkySails aboard the MV “Beluga SkySails”. After the pilot phase the towing kite will be replaced by one that is twice the size, delivering double the amount of energy and which will save two times as much fuel and climate-damaging emissions. Beluga Shipping GmbH in Bremen expects a drop in bunker costs of approximately $2,000 per operating day. The shipping company will be giving part of these savings – 20 percent – directly to the crew as an incentive. Kites with a sail surface of up to 600 square meters will be used on two larger Beluga P-Series carriers that are to be outfitted with SkySails-Systems in the future. Currently under construction, each vessel will have 20,000 tons deadweight and on-board cranes with a lifting capacity of 800 to 1,400 tons.


The WINTECC (http://www.wintecc.de/index.html) project
The goal of the WINTECC (WINd propulsion TEChnology for Cargo vessels) project, which is partly funded by the EU as part of its “LIFE“ program, is to measure the savings in energy and CO2 that can be achieved with the help of an innovative propulsion technology. “By cofunding this undertaking we want to set a clear signal for climate relevant technologies of the future. And we are delighted that the SkySails technology offers such an enormous global potential for savings“, commented Paul F. Nemitz, deputy head of the European Commission’s Maritime Policy Task Force, about promoting the project. The EU is contributing 1.2 million euros of the project’s total budget of 4 million euros as part of its “LIFE” program. Also taking part in the undertaking besides Beluga Fleet Management GmbH & Co. KG in Bremen and the manufacturer SkySails from Hamburg are the companies OceanWaveS in Lüneburg and ALDEBARAN in Hamburg. (Demonstration of an Innovative Wind Propulsion Technology for Cargo Vessels, Project Number: LIFE06 ENV/D/000479)

[Tad]

Tad,
Shipping is the most efficient transport system in terms of energy used per ton/mile carried. 800 times less than the airplane. It is also the cheapest system in terms of total cost per ton/mile. Better than trucks and even trains.
Land and air transport have also several other drawbacks, both in enviromental costs, investments needed and infrastructures saturation.
Should we ban airplanes, trucks and trains? ;)


I think the efficiency of water transport is pretty obvious to those with a understanding of basic naval architecture. But it seems to be big news to many in the transportation industry. Texas A&M University just completed a study and found that barges are the most efficient way to move cargo into the heart of the USA via the river system. Big news!

With sadness I've watched the European canal transportation system be replaced by trucking. This has endless impact, more roads, bigger bridges, more noise, pollution, oil required, etc. Barges chugging quietly up canals filled with ducks is far more sustainable long term.

I am certainly not advocating one form of transportation over any other. If things must be shipped by all means do it via water. What I am advocating is reducing the need for massive global shipping of everything via every means.

What this means is everyone thinking seriously about every purchase we make. Banning things never works, to create a truly sustainable future we must eliminate or reduce the need for the endless pollution which supports the "modern lifestyle". This involves choices, for instance I took my last jet flight several years ago. I'm done with that technology.

With further reading I have found that the Beluga SkySails delivered manufacturing equipment from Germany to a wood plant in Venezuela. Is this plant producing construction material for the folks of Venezuela? I don't know but I guess the plant is owned by foreigners producing product from cheap local materials to be shipped to the USA and Europe. No doubt it's accompanied with a "sustainable green" sticker. Americans and Europeans (being the largest consumers) have to look at this and think about the real cost to the environment for that cheap construction material.

[Guillermo]

I totally agree. One of the most significative ways to reduce the spoiling of earth is educating developed countries people to be sensible consumers instead of vain, hedonistic and compulsive ones. We shouldn't buy a new car if our old one is still going strong (and even better, increasingly use our local BMW*), we shouldn't buy several dozen pairs of shoes if we manage with just three pairs, etc, etc,etc. But unluckily this is proving to be a bigger, dificultier and slower task to perform than reducing CO2 and other emissions and wastage by just developing and using improved technology, which is our present time-race nowadays. There's no politician willing to commit political suicide by telling voters they are behaving like ungrown children. It's much easier to blame multinationals and the like, and obligue them to develope and use eco-friendly systems, whatever that means.

Cheers.

(*) BMW = Bus, Metro & Walking.

[mark424x]

http://www.skysails.info/index.php?id=64&L=1&tx_ttnews[tt_news]=104&tx_ttnews[backPid]=6&cHash=db100ad2b6

... In even moderate winds, the first flights of an initial 160-square-meter towing kite propulsion system ...
the SkySails-System pulled the ship with up to 5 tons of power at force 5 winds,



Ok, I'll be the guinea pig and get this wrong. Hopefully someone can correct me.

5 tons, guessing at 20 knots?

5 tons-force = 10,000 lbf
20 knots = 33.7 ft/s
1 HP = 550 ft lpf/s

10,000 lbf * 33.7 ft/s / 550 = 612.7 HP

612 HP/ 160 sq m = 3.8 HP/sqm

Sounds a little high. I thought their target was 2HP/sqm.

[Guillermo]

Yes, 5 tons sounds pretty high for a 160 sqm kite as an average. If my memory doesn't fail me, 1.4 HP was the expected average and 2 HP a maximum one. Probably that figure is instant pull at some point of the dynamic flight in a certain moment, so a maximum (they continuously record pull at the constant-tension whinch). I'll ask the guys.

Cheers.

[juiceclark]

Love it! I wonder if one could utilize a dinghy davit dual purpose for launching the sail? You know...attach the sail to the davit, point it straight-up, extend fully and then release.

The sail just seems the most convenient and idiot-proof way to take advantage of wind propulsion in a power boat. Moreover, there's nothing in the way when not in use. If I can run a 50' sportfish at 7k with the genny pushing hydrolics, I'll bet a small sail could give us 11k or 5k without power.

Tony in Sw FL

[Guillermo]

Love it! I wonder if one could utilize a dinghy davit dual purpose for launching the sail? You know...attach the sail to the davit, point it straight-up, extend fully and then release.

Sensible idea! Probably an hydraulic crane with a double use for kite launcher and deck hardware and light cargo handlig, could significantly reduce the initial investment. :)

Cheers.

[mark424x]

Love it! I wonder if one could utilize a dinghy davit dual purpose for launching the sail? You know...attach the sail to the davit, point it straight-up, extend fully and then release.


Yes, nice idea. Certainly the key to making this successful is the launch and recovery process. I'd think for powerboaters to go for it, it would have to be as easy as a furling system on a sailboat. A couple other thoughts:

Perhaps a small pilot kite that would have just enough power to keep a collapsed main kite aloft, with say 50' of line attached to the main kite (so it would fly above the main kite). If you could de-power the main kite, you would also use the pilot kite to keep the main kite out of the water during recovery. One of my goals would be to use a kite for roll stabilization in addition to motive power. Perhaps the small pilot kite could be used stand alone in heavier air or just for some roll stabilization.

I'd also think you'd want to have little tension in the control lines, so while the main force is applied to the boat at the optimal place, control could be done from a flybridge, portugese bridge, or other convenient location.

Optimally, we'd have some sort of snuffer or sock, perhaps an on deck tube that you draw the kite into for storage/relaunch, again to make launch/recovery very simple and easy for one person.

[Guillermo]

It's difficult (although probably not impossible) the kite to collapse down, as it is obligued to constantly fly in a figure of eight by the canopy actuator. All control lines are brought to this canopy.

Interestingly, one of the main challenges to develope the Skysails was the towing cable, as it has to host the control wires in its core, which brings the problem of the matching of the different stretching properties of the various materials.

Launching and retrieving the kite in a simple manner was the main goal, as it is basic not obliging to increase the crew number or make them to learn and perform hard skills. As far as I know it's now a matter of a couple of ordinary seamen with little fuss. A kite hosting underdeck tube has already been considered.

Cheers.

[mark424x]

It's difficult (although probably not impossible) the kite to collapse down, as it is obligued to constantly fly in a figure of eight by the canopy actuator. All control lines are brought to this canopy.


I understand. I was thinking of the case of a modest pleasurecraft and assuming that it would be a passive kite without active flight patterns and controller. Thanks.

[brian eiland]

Smoother sailing on kite-and-diesel hybrid ships

From sails to steam to diesel – and back to sails. That’s what some innovative shipping companies advocate to clean up the polluting cocktail of smokestack spew from tankers (http://www.rit.edu/news/?r=45889)and yachts. As a proof of concept, this week the MV Beluga SkySails, a ship outfitted with a 160-square-meter kite, finished a breezy voyage from Germany to Venezuela, the United States and Norway, powered in part by wind across 11,952 nautical miles.

The Beluga SkySails system uses software that charts a course to find the best wind conditions, and compressed air to change the angle of the kite to match different wind speeds and weather. The European Union-funded company’s chief executive expects to see fuel savings of 10 to 35 percent using wind power, depending on the route. To achieve further increases, the company expects to move to a larger sail of about 320 square meters later in 2008.

Kites are more than just a gimmick; simple as they may be, they’re a legitimate avenue of research, along with investigations into speed reductions, the potential to switch to less harmful fuels from diesel, and the elimination of drag. For example, in 2005 a shipping company unveiled its “concept car carrier” – alas, not the platform upon which all concept cars are shuttled around to motor shows, but rather a zero-emissions, solar/wind/fuel-cell-powered tanker called the E/S Orcelle (http://www.walleniusmarine.com/qse.jsp?art_id=120). But before that vessel makes it out into the open waters, we’ll more likely see ships run on gas, probably with sleeker profiles and improvements in propeller design. Consider, for example, a company called PAX Scientific (http://www.paxscientific.com/) that designs biomimetic, spiral-shaped turbines that could help ships cut through water more smoothly, improving their fuel efficiency by about 10 percent.

It remains to be seen whether retrofitting sails to tankers will catch on, but Skysails estimates the potential upgrade market for its system at more than 40,000 ships. Through 2013, Skysails is targeting (http://www.greencarcongress.com/2006/01/beluga_shipping.html) less than 1% of that market—about 400 ships.

A key part of the success of sails will depend on incorporating satellite predictions and long-range weather forecasts to help chart courses that are energy-efficient without sacrificing much on speed. Past efforts to launch kite-based ship propulsion have floundered due to the unpredictability of wind conditions.

And there’s definitely room for improvement in long-distance shipping. A 2003 University of Delaware study found that the world shipping fleet consumes about 289 million tons of fuel each year, of course accompanied by a gargantuan emissions profile. According to Geotimes (http://www.geotimes.org/mar08/article.html?id=nn_wind.html), “the world’s fleet of cargo ships, fueled by refinery leftovers — black sludge that’s cheaper and thicker than crude oil — emits more carbon dioxide than the world’s fleet of airplanes.”

...from a blog "Plenty" green magazine

[Guillermo]

Skysails' first fly on the MV "Michael A"

http://s2.streamingfarm.tv/streamingfarm/skysails/20080120_Michael_A_Flugfilm_02_1000k.wmv

Cheers

[kach22i]

I've just discovered that the "kite" method may not be "new age" but before 2000BC!

Check this out.

Mysterious Stern Appendage
http://www.worldwideflood.com/ark/hull_form/ancient_hull_form.htm
Compared to ancient construction in stone, we know relatively little about ancient ships, especially anything prior to 2000 B.C.

http://www.worldwideflood.com/ark/hull_form/ancient_ship_files/clay.gif
http://www.worldwideflood.com/ark/hull_form/ancient_ship_files/Syros_terracotta.jpg
http://www.worldwideflood.com/ark/hull_form/ancient_ship_files/Syros.gif
A fish symbol appears to be mounted on a pivot at the top of the prow, perhaps acting as a wind vane to detect wind direction relative to the vessel.

Looks more like a kite to me, how about you?

What do you see?

I see a BOW Appendage for kite drive.:)

Video of a modern kite sail in action:
http://www.metacafe.com/watch/766538/kiteboat_hawaii/

http://willienelsonpri.com/peace/370/a-peaceful-solution-dan-tracy.html
http://willienelsonpri.com/wp-content/uploads/2007/09/dantracy.jpg

The bow prowl kind of acts like the rod in the rod & reel in the video. In this ancient boat a crew member could scale the bow apendage and untangle the kite if needed. This design would be less likely in allowing the kite to touch the water and get wet. No synethic cloth back then, they would want to keep the cotton or silk dry at all cost.

[Guillermo]

A stern kite....? ;)
I'd rather bet for a stern wind vane, as those ships, if sail rigged, only could go with the wind. Interestingly, there seems to be no sails rigged. :p

Cheers.

[kach22i]

A stern kite....? ;)
I'd rather bet for a stern wind vane, as those ships, if sail rigged, only could go with the wind. Interestingly, there seems to be no sails rigged. :p

Cheers.
When the archeologist and historians moved over and let mechanical engineers look at Leonardo DaVinci's drawings there was a massive change in interpretation. They then went and tried to build some of these inventions and the results and interpretations were once again different.

[Guillermo]

May I do an interpretation?
Let's see...

What I see is a rowing war ship making head against wind and rolling waves (sailing right to left in the engraving), probably a 16 oars (each side) predecessor of the penteconter, with its mast abated. If with 30 oars it would have been a triaconter, or it could have also been a lembos or lemboi. The fishy symbol on the artistically overheighted stern can be the emblem of its captain or king, or any other relevant person or deity. It was common to fly a fillet or pennon (ταινία, fascia, taenia) attached behind the aplustre, which served both to distinguish and adorn the vessel, and also to show the direction of the wind. (But I don't refuse your kite theory....:) )

A relevant captain of a triaconter was Hieron, a pilot or navigator of Soli in Cilicia, sent out by Alexander to explore the southern shores of the Erythraean sea, and circumnavigate Arabia. He advanced much further than any previous navigator had done, but at length returned, apparently discouraged by the unexpected extent of the Arabian coast, and reported on his return that Arabia was nearly as large as India.


Cheers.

P.S.
Interesting article: http://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Navis.html
Interesting book: http://books.google.es/books?id=sDpMh0gK2OUC&pg=PA125&lpg=PA125&dq=triaconter+oars&source=web&ots=SzFY06mqrl&sig=EDYctuDGxDRTCKvkFIQtxs_PSBw&hl=es#PPP1,M1

[kach22i]

Looks like I'm just going to have to build a large scale model and prove it to everybody.:)

I'll give this a distant second place explaination..........
http://en.wikipedia.org/wiki/Kite#History
Kites have been used for military uses in the past for signaling...........

[Guillermo]

George,
As said I don't refuse your kite theory. They could have been used to test the wind, signaling and communication. Interesting.

Cheers.

[kach22i]

A few years ago I designed a logo for a friend getting into the import business. He wanted to include an ancient Greek sailing ship into it. I never quite figured out the purpose of the stern fin, was it decorative only, or did it serve a purpose?

http://i184.photobucket.com/albums/x295/kach22i/MISC/Greek-American-1JPG.jpg

Answering this may help in answering questions about even older boats and ships.

[Guillermo]

Aplustre (or Aplustria) Meaning and Definition:
(n.) An ornamental appendage of wood at the ship's stern, usually spreading like a fan and curved like a bird's feather.

From http://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Navis.html:

"The stern (πρύμνη, puppis) was generally above the other parts of the deck, and in it the helmsman had his elevated seat. It is seen in the representations of ancient vessels to be rounder than the prow, though its extremity is likewise sharp. The stern was, like the prow, adorned in various ways, but especially with the image of the tutelary deity of the vessel (tutela). In some representations a kind of roof is formed over the head of the steersman, and the upper part of the stern frequently has an elegant ornament called aplustre, and in Greek ἄφλαστον, which constituted the highest part of the poop. It formed a corresponding ornament to the ἀκροστόλιον at the prow. At the junction of the aplustre with the stern on which it was based, we commonly observe an ornament resembling a circular shield: this was called ἀσπιδεῖον or ἀσπιδίσκη. It is seen on the two aplustria here represented (cf. Apollon. Rhod. I.1089, II.601; Apollod. I.9 §22; Hom Il. XV.716; Herod. VI.114). The aplustre rose immediately behind the gubernator, and served in some degree to protect him from wind and rain. Sometimes there appears, besides the aplustre, a pole, to which a fillet or pennon (ταινία) was attached, which served both to distinguish and adorn the vessel, and also to show the direction of the wind. In the column of Trajan, a lantern is suspended from the aplustre so as to hang over the deck before the helmsman.

The aplustre commonly consisted of thin planks, and presented a broad surface to the sky. In consequence of its conspicuous place and beautiful form, the aplustre was often taken as the emblem of maritime affairs: it was carried off in triumph by the victor in a naval engagement (Juven. X.135), and Neptune is sometimes represented on medals holding the aplustre in his right hand, as in the annexed woodcut; and in the celebrated Apotheosis of Homer, now in the British Museum, the female personating the Odyssey exhibits the same emblem in reference to the voyages of Odysseus."


From: http://www.ancientlibrary.com/smith-dgra/0646.html
"Besides the badge which distinguished each individual ship, and which was either an engraved and painted wooden image forming part of the prow, or a figure often accompanied by a name and painted on both the bows of the vessel, other insignia, which could be elevated or lowered at pleasure, were requisite in naval engagements. These were probably flags or standards, fixed to the aplustre or to the top of the mast, and serving to mark all those vessels which belonged to the same fleet or to the same nation. Such were " the Attic" and " the Persic signals" .... A purple sail indicated the admiral's ship among the Romans, and flags of different colours were used in the fleet of Alexander the Great."



Cheers.

[kach22i]

The Greek ship is too far removed for the sail discussion, although it's very interesting as well.

A Phoenician Bireme...........much closer to the main topic and much older too.

Link to image:
http://etc.usf.edu/clipart/19300/19323/bireme_19323.htm


http://en.wikipedia.org/wiki/Phoenicians
http://upload.wikimedia.org/wikipedia/commons/b/b2/PhoenicianCoin2A.jpg
............................................................


http://www.catshaman.com/15Sailors/05sailors12.htm
Cycladic ships
http://www.catshaman.com/15Sailors/image4809.JPG
http://www.catshaman.com/15Sailors/image4833.JPG
.........................................

http://www.catshaman.com/15Sailors/05sailors1.htm
http://www.catshaman.com/15Sailors/image4799.JPG
After his research Bjoern Landstroem made this drawing of a goat ship.

http://www.catshaman.com/15Sailors/05sailors1.htm
http://www.catshaman.com/15Sailors/0petrie.JPG
Evidence of three seasons in 4th millennium Naqada.

[Guillermo]

The Cyclades are Greek islands.

"By about 2000BC the Mainland and Island Greeks were beginning to take an increasing interest in the navigation of the Eastern Mediterranean. As early as the third millenium it is possible to distinguish at least two kinds of ships in use in the Aegean. Firstly there are representations in the bottom of shallow terracotta dishes of what have come to be known as 'fry pan' ships. These are characteristically long narrow vessels with a high projection at one end and a projecting foot or ram at the other. The question of which is stem and which is stern is not clear and has been the subject of considerable academic controversy. The high projection is usually decorated with a fish and a hanging tassle.
........................
At this point it is necessary to return to the third millenium Aegean 'Fry Pan' ships. The problem here is to decide which was the stem and which was the stern since it is not possible to determine the direction in which the boat is moving. Logically the fish emblem might be expected to point forward in which case the high projection must by the stem. If so, what is the function of the projection at the stern which clearly cannot be a ram ? Casson argues that the stern projection was a skid to protect the stern when beaching the boat stern first. Morrison by contrast argues that the projection was a ram at the stem and the high projection was at the stern, to protect the steersman against a following sea. Marinatos observed that in Cretan and Mycenean hieroglyphs ship symbols always point in one direction which is opposite to the direction of the writing whilst symbols for living things, including fish, point in the direction of the writing. It follows that the high projection must be the stern of the boat, and the low projection must therefore be a skid of ram at the bow. It is also quite possible that early builders of keel boats were unable to produce a satisfactory scarf between the end of the keel and the stern post and adopted the simpler solution of dropping the stem post into a mortise joint cut into the upper surface of the forward end of the keel. In this event that part of the keel which projected forward of the mortise joint would be left as a projecting foot to protect that mortise joint behind it. Its purpose is thus structural rather than functional. Such methods can be found in Bronze Age Northern European boats."

http://www.cma.soton.ac.uk/HistShip/shlect18.htm

Also curious:

"It seems certain that early river ships and particularly the open sea ships used a compass in the shape of a fish as did the ancient Chinese ships. Also fish compasses were found on Cycladic Neolithic frying pans and on Viking boats."

http://www.greecetravel.com/archaeology/mitsopoulou/boats.html


Cheers.

[kach22i]

The Cyclades are Greek islands.
http://www.greecetravel.com/archaeology/mitsopoulou/boats.html

That is a nice quote and link Guillermo.

It makes sense to me, that mankind would mimic nature and being a land dweling creature take his land based technology and attempt to apply it to the sea. I wish this to mean that he took a kite with him on a boat and the rest is history.

However I'm having some doubts as one image which I cannot seem to find twice showed a guy fishing at the bow, or I should say pulling up a fish from the sea. There are so many images that it's all becoming blurred.

The new thought in my head is that the fish may indicate the season or even a destination such as home, or a far away trading port.

I have to one day I will have to build a simple model and see if this works, then let the arguments fly.;)


EDIT:
That last image reminds me of a World War II Barrage Balloon.
http://www.history.navy.mil/photos/events/wwii-eur/normandy/normandy.htm
http://www.history.navy.mil/photos/images/d00001/d02333.jpg
A convoy of Landing Craft Infantry (Large) sails across the English Channel toward the Normandy Invasion beaches on "D-Day", 6 June 1944. Each of these landing craft is towing a barrage balloon for protection against low-flying German aircraft.

[Guillermo]

OK.
So we have several possibilities by now:
1.- A kite to propel the ship.
2.- A kite as a comms signal between ships.
3.- A magnified representation of the more important instrument aboard: the compass.
4.- A marking signal to identify the captain, king, nation or deity.
5.- A weathercock to show the direction of wind.
6.- A symbol to represent fishing

As almost all the representations I have been able to find displaying the fishy thing, have no masts, I'd eliminate the weathercock option and, as those were war ships, I'd eliminate also the fishing posibility.

To fly a propulsion kite from the highest (and more difficult to reach) point of the ship would have been not very sensible from the stability point of view, nor there are (known to me ) precedents of kites having previously been used for propulsion purposes on land.

I vote for possibilities 2, 3 or 4 (with a present tendency for #3), but would love to see your model and tests whenever you do them. :)

Cheers and good night (here).

[kach22i]

You forgot the blimp theory, they had blimps - fed the boys beans for the methane.

[masalai]

Methane to burn to make the hot air? not that good for balloons...

[Guillermo]

The problem with the compass theory is that, as far as is known, compasses were not yet invented 3000 years b.c. ;) There is discussion about when they were, but for sure a sofisticated navigation instrument like that was not available at the time. Not even in the times of Alexander. The earliest reference to a specific magnetic direction finder device is recorded in a Song Dynasty book dated to 1040-44 a.c. Here we find a description of an iron "south-pointing fish" floating in a bowl of water.
http://en.wikipedia.org/wiki/Compass
So there seems to go to hell this otherwise tempting theory :)

Now, apart from the 'blimp' theory, which probably is only related with some of the captains being old fat farts :D , we only have two remaining ones, #2 and #4, which can even join in a single one. But for the time being, I'll stick to #4, my initial one.

Quod erat demonstrandum.

.............

Another interesting consideration on the prow-stern discussion on Cycladic ships: from the point of view of aerodinamics it makes very little sense to have a very high and big sail area just at the very end of the bow, as it would have made those vessels totally unsteereable in something stronger than a force 1 generally speaking. So I bet again for such a protuberancy being the 'aplustre' at the stern and the pointy thing at the other end being an ornamental, not combat oriented, ram.

You're right: we urgently need NAs to help the historians....:)

Cheers.

[kach22i]

Since I've hi-jacked this thread and feel ashamed, in an effort to get back on topic I pose a new question.

When, where and who was the first kite sail used and or invented............offiical western civilization explanations and alternate theories will be accepted.

Wiki links will also be considered.

[Pericles]

http://www.kitelife.com/archives/SEPT98/kite.htm

http://special.lib.gla.ac.uk/exhibns/month/mar2001.html

The first records of man-lifting kites come from China. Their use is mentioned in Sun Tzu's The Art of War as a means of viewing the movements of enemy troops. In a story about the Japanese thief Ishikawa Goemon (1558-1594), he used a man-lifting kite to allow him to steal the golden scales from a pair of ornamental fish images which were mounted on the top of Nagoya Castle. His men manoeuvered him into the air on a trapeze attached to the tail of a giant kite. He flew to the rooftop where he stole the scales, and was then lowered and escaped. In the 17th century, Japanese architect Kawamura Zuiken used kites to lift his workmen during construction. George Pocock, who invented a kite-drawn buggy in 1822, had previously used kites as a method of lifting men to inaccessible cliff tops, but it was not until around the 1880s that there was serious interest in developing man-lifting kites.

http://en.wikipedia.org/wiki/Man-lifting_kite

http://www.dcss.org/speedsl/KiteTugs.html

Good information here.

http://www.aka.kite.org/?traction.html

Polynesians may have used traction kites. They wove their crab claw sails. I am looking for information on fishing kites as well.

http://tobi.gmu.edu/tobithings/fishing/anell1955.pdf

http://www.asiafinest.com/forum/lofiversion/index.php/t39391-150.html

http://subvision.net/sky/planetkite/asia/indonesia/sulawesi-muna.htm

Pericles

[Greenseas2]

I've been trackiing this thread with interest and it is one of the VERY INTERESTING threads. Consequently, a few of us decided to hook a sailboard kite to my 30 foot S2 center cockpit sloop and go to sea (to give more maneuvering room). Kites work well and we were sailing under the kite alone at past-hull-speed velocity when the wind shifted 90 degrees. There are 3 pools of yellow water on the cockpit floor where the crew had been sitting and drips all of the way to the bow from the instant change in direction of the kite. Must say that kites are a powerful way to make a boat go. A once in a lifetime experiment.

[kach22i]

Good information here.

http://www.aka.kite.org/?traction.html


Second sentence:
Kites have been used to pull large sailing ships from wind sheltered harbors

The ship I first posted may have operated close to the shore going in between small islands, coves and harbors where a constant wind at sea level would be hard to come by.

...................................................................


http://subvision.net/sky/planetkite/asia/indonesia/sulawesi-muna.htm

Pericles

Wow, cave drawings of kites in use..............freaking me out man.

[kach22i]

30 foot ..........we were sailing under the kite alone at past-hull-speed velocity when the wind shifted 90 degrees.

How large was this kite and what was to station it to?

I would imagine that if the line were attached at a point at or below neck level, one could lose their head with an abrupt change in wind direction as described.

[Greenseas2]

Didn't measure the kite but it was of the standard wind surfer design. The experiment was just a fun thing and no serious considerations were taken other than attaching the beast to the boat through the midships blocks and winches designed for a spinnaker. I do admit that it was fun, with the exception on the 90 degree wind change. Suggest that anyone else doing this should attach a "spill line" to either partially dump or totally spill the wind if necessary. A big part of the problem was that we became too complacent with a new device that appeared to work well and should be explored further. There's a lot of great information on this thread, so don't let the actions of a few senior citizens stop you for going further with it.

[kach22i]

I found an old post of mine.................with main sail down that sunflower thing would still give the ship a little push.

http://boatdesign.net/forums/showthread.php?p=169280#post169280
I wonder if the ancient Greeks knew about the bulb-bow, and that it was more than just something to ram another ship with?

http://www.science.sakhalin.ru/Ship/Vlad_E1.html
http://www.science.sakhalin.ru/Ship/Img-S/Pic_04.gif

[brian eiland]

Since I've hi-jacked this thread and feel ashamed, in an effort to get back on topic I pose a new question.

No problem kach22i, at least you hijacked it with something of intelligence to contribute

[kach22i]

No problem kach22i, at least you hijacked it with something of intelligence to contribute
Cool, I did get sidetracked on the lighter than air gas thing though.

Fish kites....................back on to the side topic.

http://www.gombergkites.com/plynn2.html
http://www.gombergkites.com/LM-FISH1.JPG

http://www.goodorient.com/Chinese_Triangle_Golden_Fish_Kite_P21578
http://www.goodorient.com/images/P/GKI1019_200.jpg

Wind Socks
http://www.foreverflying.com/laundry.html
http://www.foreverflying.com/GF-Fish23.jpg

http://www.getoutdoors.com/goblog/index.php?/archives/983-Kite-Fishing.html
http://www.getoutdoors.com/goblog/uploads/kite-fishing.jpg


http://horsesmouth.typepad.com/hm/kite_surfing/index.html
http://img.photobucket.com/albums/v251/joserouse/Sailing/kite1_500.jpg

[brian eiland]

Another video of a small cat being powered by a kite

http://www.kiteboat.com/kb_videos.html

[masalai]

Thanks folks, nice video & pics, nearly there but not yet for cruisers - particularly us old codgers......

[Greenseas2]

I really enjoyed the video of the cat under kite power, and it appears that there was good control of both boat and kite even though it required two people steering, one for the boat and one for the kite. Somewhere in one of the shipping journals I recently saw some small Japanese freighters using cylindrical sails. The shaft of the cylinder was attached, through a transmission, to the prop drive shaft. With this arrangement wind direction and sail control offers no problems or concerns even though wind force may. The only draw back with the cylindrical sails might be appearance, but it does offer direct drive and free motive power to a vessel.

[eponodyne]

I'm *just* about to order an i550 kit; I plan on powering it with a 12 sq m Cabrinha bow kite I got off Craigslist for a song. I hope to be documenting my build of it on the Woodenboat forum.

I like what Dan Tracy has done. I think it's a huge step forward. I hope to add my mite to the knowledge base of kites and boats. I've been thinking about this for quite some time, and hope to incorporate some ideas that may be useful:

-One pilot, center-mounted with a wheel in front of him. Rudder controlled by pedals.

-Kite lines lead to a car on a track, off-the-shelf Harken. Semicircular in shape, this provides a constant radius for secondary lines leading back to a yoke in front of the helmsman. By using a combination of cams and bellcranks on these lines, I should be able to get enough travel out of the yoke to be able to move the kite around the way it should be. In addition, this zemicircular track will reach from beam to beam, and be gimballed so it can match angles with the kite lines.

-The important thing about this arrangement is that on a reach, the pull of the kite will be coming from the leeward side of the boat. Heelin moment is thus reduced to a minimum. Control of the kite side-to-side on this track will be provided by the lowly rope and 2 cam cleats, with short lines on a spring, or push-pull cables to open them as needed. I don't need to have a 6:1 control system to anchor the car, I just need to let the kite fly from side to side. The whole point is that the kite is controllable.

-No ballast needed, or very minimal ballast just to make the boat less tiddly.

-I intend to build a full-span trim tab into the trailing edge of the daggerboard((s), I may go with tandem boards)). Guys, we been going about the trim-tab idea all wrong, wrong, wrong. Think about it: When you install a moveable trailing edge on a symmetrical foil in a medium as dense as water, anything past just a few degrees of adjustment to the trailing edge, and you don't have a trim tab.

You have a flap. So why not build the wretched thing as a flap? I don't think we need to look at leading-edge slots and Fowler extendible flaps just quite yet. But if you want to work upwind to (say) port, then doesn't it make sense to provide lift to port by "lowering" the flap on the centerboard or daggerboard or whatever, let's say... 20 degrees to starboard? Smell what I'm steppin in here?

I see no reason why this idea won't work. If I am wrong and it doesn't, then some Sunday afternoon I pull the boat out and I center the flap and fair over it, with no real damage done.



Questions, concerns, hints, allegations, things left unsaid?

[masalai]

Please keep us posted on Boatdesign.... We are many who are hanging in the wings... Good luck..

[Greenseas2]

Don't knock the leading edge Krueger flaps (simple leading edge slots) and trailing Fowler flaps. Those devices can help keep your air foil up in very light winds. They're used in the Swiss Helio Courier and Turbo Porter aircraft for ultra slow flight and short field landings/take-off capability. Before that they were use on the German Feisler Storch STOL aircraft for the same reason and are now used on the Slepcev Storch and other STOL aircraft. The steerable parasail device is fairly technical in nature and all design consideration should be taken in to consideration. Who knows? Maybe the parasail design for your boat mightl also have some nuances that potentially could benefit the aviation world as well. Good luck!

[FAST FRED]

Best use we have found for a kite is cruising the Bahamas.

Send the kite up and the slower cruising buddies can tell which lump of similar land you are actually at.

FF

[Greenseas2]

Eponodyne, you are partially correct with the flap deployed on one side; however, it's more in line with a "flaperon" that can be left in the full or partially down position to crab in to the wind. What is being bordered on at this point is an air inflated sail that can accommodate the various kite/sail control surfaces desired not to disclude spoilers for fast ditching of the sail if needed. Sail or wing tip winglets might also have a controlling effect of sail/kite yaw. Not to be out done by Fast Fred this morning, you might want to put wheels on the hull too in case you can't get the sail down before beach impact. LOL

[eponodyne]

Don't knock the leading edge Krueger flaps (simple leading edge slots) and trailing Fowler flaps. Those devices can help keep your air foil up in very light winds. They're used in the Swiss Helio Courier and Turbo Porter aircraft for ultra slow flight and short field landings/take-off capability. Before that they were use on the German Feisler Storch STOL aircraft for the same reason and are now used on the Slepcev Storch and other STOL aircraft. The steerable parasail device is fairly technical in nature and all design consideration should be taken in to consideration. Who knows? Maybe the parasail design for your boat mightl also have some nuances that potentially could benefit the aviation world as well. Good luck!


I was talking about using a flap on the daggerboard, to help work to windward. The best you can get right now is about 50 degrees true, which isn't pointing very high at all. I thought about cutting up a couple of windsurf kites and using them as a 'hard sail' but water launches would be if not outright impossible then a straight up, old skool sonofabitch. The advantage with something like that is one could use leading edge flaps but the weight and complexity just doesn't justify the results. For keeping the kite up in light air I'm thinking I'm gonna use helium LOL.

[eponodyne]

I never have figured out the edit function on this goofy format--but I want to add that these kiteboarders already figured out that it's necessarty to able to ditch the thing in a hurry. They call it a "chicken loop," and it's a pelican-hook affair that either unsheets the kite (yes, there are provisions for sheeting in and out by varying the angle of attcak) and/or detatching it from the harness completely, and retaining the control bar by one end or another. The kite then loses lift on one side, does a pretty quick dive to the water; you swim over to the bar, reset the chicken loop, and re-launch. Not that hard.

[Greenseas2]

In the design effort of a vessel using a parasail/kite as the main source of propulsion, it might be a good idea to separate the parasail design from the vessel design. Being that the prime mover in this case is the parasail/kite, it may be more prudent to start with this design effort first, and the finished product will probably be far removed from the typical common parasail of today. Inflatable, possibly yes, helium, No....too expensive over a period of time and hard to ditch in an emergency. As it stands at this point, the parasail is a kissin' cousin to a square rigger's top gallant and top royal sails.

[eponodyne]

Oh, no. No no no no no. These aren't parasails. They're parafoils, which is completely different if you disregard the fact that both designs are made out of cloth. Google 'traction kite' for a bajillion hits and tons of info; but in a nutshell, these kites are shaped overall like a section of a sphere (so lift is roughly equal no matter where the kite is relative to you) and in section like an airfoil. And they're no joke. That 12-sq-m will pick me right up off the ground in 15 mph of wind, and I weigh 265 pounds (like, what, 125 kilo?). Naish makes a monster that has something like 27 or 30 sq. m.

I don't need to do my own research on this. Naish, Cabrinha, SLingshot, Ocean Rodeo and a whole bunch of others have people on staff they're paying good money to do research for me (Ssshhh. They don't know that yet...).

[Greenseas2]

Good show on the references Eponodyne, this is the sort of supporting data that is needed on threads such as this. Still, any product can stand improvement to meet a specific need.

[kach22i]

I'm *just* about to order an i550 kit; I plan on powering it with a 12 sq m Cabrinha bow kite
Are you still going to have a mast?

[eponodyne]

Are you still going to have a mast?
Nope. It would only get in the way. For the very lightest of airs, Minn-Kota has some excellent selections.

[kach22i]

Nope. It would only get in the way. For the very lightest of airs, Minn-Kota has some excellent selections.
Will the kite be mounted where the mast mounting is/would be?

A bow mounting would have a very different behavior, right?

[eponodyne]

Yes, mounting it on the bow would be a simple solution but not at all a viable one.

I'm going to tie the kite off to a C-shaped track that runs from beam to beam, and that's going to be mounted on swivels on each gunwale, so it can lift and maintain angle. Think gigantic C-clamp, sort of thing. This will, in turn, be mounted on a tracks on each side deck, each about a foot and a half long and centered on the CG of the boat. Ya folla? So the kite will be pulling from the leeward side on a reach, and from wherever else on the track everything's happiest on other points of sail; and this whole kite-track lashup in turn can move fore and aft a little to compensate for sea conditions or speed or whatever. I can do this all with off-the-shelf Harken tracks and traveller cars, and this should be well within the forces that the hardware can handle, in any sort of wind state in which I'd have this thing out.

It's important that the kite track be a true semi-circle, so I can set up a bellcrank/cam arrangement for each side of the kite-- about a 1:3 input/output ratio. You don't need a lot of force to turn these kites: you don't fly them by sheeting one side in, you steer by dumping lift off the opposite side. Anyway, if distance from the yoke to the control track is constant, then I can do this with lines and pulleys, from the yoke, below the cockpit sole, forward, and up through the deck through pulleys. I don't want to get into Teleflex push-pull cables because they're pretty expensive, but I do understand I may have to eventually. It's not that hard to move things around to suit, and that's the major reason I'm picking the i550 to do it with, as for a quick little sport boat, it is after all just stitch-and-glue plywood. It'll be easy to beef up where it needs more beef, and I can modify everything pretty easily.

Oh, yeah: kite launch and recovery: 3 Fin-Nor saltwater gamefish reels, linked together so they all run the same speed. Little tiny stout gear-reduction winches, eh?

[tspeer]

I don't think we need to look at leading-edge slots and Fowler extendible flaps just quite yet. But if you want to work upwind to (say) port, then doesn't it make sense to provide lift to port by "lowering" the flap on the centerboard or daggerboard or whatever, let's say... 20 degrees to starboard? Smell what I'm steppin in here?...

You're right that it is a flap. You're wrong that it produces more lift on a beat, except that it increases the maximum lift so the board doesn't stall out in a tack. What it does do is rotate the hull so it points in the direction of travel.

I've pointed this out on other threads, but the lift on the board is equal to what is required to offset the side force from the sail. That doesn't change by putting a flap on the board. Instead the flapped board produces the same lift at a lower angle of attack (leeway angle). However, the path of the boat through the water is determined by the lift/drag ratio of the hull+foils and the lift/drag ratio of everything above the waterline. If the flap doesn't change the lift/drag ratio, then the path through the water doesn't change. So the boat with the flap sails with the bow off the wind compared to the boat with the symmetrical board.

Since the lift is set by the sail trim, not the board configuration, the point of adding a flap is not to increase the lift when sailing steadily on a beat, but to reduce the drag. Many modern (WWII and later) sections have a low-drag "bucket" in their drag polar that can have a profile drag coefficient less than half of what it is just outside the bucket. With a symmetrical section, the drag bucket is necessarily centered on zero lift, and unless you have an over-sized board you will be operating outside the drag bucket. But with a flap, you can move the drag bucket to center it on your operating condition.

If you're not going to use the flap that way, then you're about as well off to pick a more robust symmetrical section that has a higher minimum drag but lower drag at the operating condition.

[eponodyne]

Since the lift is set by the sail trim, not the board configuration, the point of adding a flap is not to increase the lift when sailing steadily on a beat, but to reduce the drag. Many modern (WWII and later) sections have a low-drag "bucket" in their drag polar that can have a profile drag coefficient less than half of what it is just outside the bucket. With a symmetrical section, the drag bucket is necessarily centered on zero lift, and unless you have an over-sized board you will be operating outside the drag bucket. But with a flap, you can move the drag bucket to center it on your operating condition.

If you're not going to use the flap that way, then you're about as well off to pick a more robust symmetrical section that has a higher minimum drag but lower drag at the operating condition.


But what about if sail trim can vary more widely than what can be determined by cloths on a stick? With a kite, lift is coming from a point well outside the hull itself; and with what I'm going to build, heeling moment is going to be reduced to an absolute minimum. I think this is a worthwile avenue to explore, simply because a flapped daggerboard and a traction kite have as far as I know never been used on the same vessel.



Tandem daggerboards? What do people here think about that idea?

[tspeer]

But what about if sail trim can vary more widely than what can be determined by cloths on a stick? With a kite, lift is coming from a point well outside the hull itself...

The same thing applies - the lift on the board is determined by the force from the kite. To see why, consider these cases:

(For simplicity, assume the hull has rounded sections such that the side force from the hull is negligible compared to the side force from the board)

1. The kite is pulling the boat dead downwind, and the flap is not deflected.
What is the lift on the board? Zero.
What is the boat's heading? Dead downwind.

2. The boat is traveling to windward, and the kite is pulling mostly sideways and a little forward. The flap is not deflected.
What is the lift on the board? High.
What is the boat's heading? Pointed to weather of the course through the water by the board angle of attack required to produce the required lift.

3. The kite is pulling the boat on a straight line course dead downwind, and the flap is deflected.
What is the lift on the board? Zero.
What is the heading of the boat? Pointed to the same side of the course as the flap trailing edge, by the amount of the zero lift angle of attack of the board. This will be a negative angle of attack for a positive flap deflection.

4. The boat is traveling to windward at the same speed and course as case 2. The kite is pulling in the same direction relative to the apparent wind.
What is the lift on the board? High, and the same magnitude as for case 2.
What is the heading of the boat? The bow will be pointed to leeward compared to case 2 by the amount of the zero lift angle of attack corresponding to the flap deflection.

Note that cases 1 and 2 have the same board configuration, but different amounts of lift. The same for cases 3 and 4. Cases 1 and 3 have the same lift, but different board configurations. So the lift cannot be determined by the board configuration.

Cases 1 and 3 have the same lift and the same kite orientation with respect to the wind. Cases 2 and 4 have the same lift and the same kite orientation with respect to the wind. So the lift is evidently determined by the trim of the kite relative to the direction of travel.

For cases 3 and 4, the bow of the boat is rotated relative to cases 1 and 2. In fact, when sailing in a straight line, the difference in the boat's heading between the flap centered and flap deflected cases will be essentially the same on all points of sail and at all speeds. This is because the flap shifts the lift coefficient vs angle of attack curve, but does not change the slope of the lift coefficient vs angle of attack curve. If the angle of attack is measured from the zero lift angle instead of the plane of the board, then the angle of attack for cases 1 and 3, and cases 2 and 4, will be the same.

I suspect you'll agree with what I've said for cases 1 - 3, but case 4 comes as a surprise. It is counter-intuitive, perhaps, but I think you'll see that if you accept case 3, then case 4 follows directly from it.

And it matches what we all know intuitively - What's the purpose of the board? To counter the side force from the sail/kite. If the kite didn't produce side force, then the board wouldn't be needed at all - for the same reason power boats don't have boards. So the lift on the board has to be all about the sail/kite.

[eponodyne]

What about Case 5: Boat travelling to windward
Kite pulling mostly ahead and a little sideways
Trailing edge deflected to leeward

So the bow of the boat is deflected to windward--right?-- and if I keep everything balanced to *just* before the keel stalls, then that should net me a greater windward moment than without a trailing edge flap. I understand that this is going to cost me speed due to lift-induced drag (nothing is free, my powers are many but I can't refute the laws of physics just quite yet). You're forgetting that the kite can be sheeted independantly of direction of pull; I can hang the kite anywere in the wind window and keep it hovering just short of a stall, or sheet in and produce a truly impressive yank. Efficiency dies out toward the edges of the wind window but lift on the kite happens any time air flows over the top faster than the bottom.

I'm going to give this a try to attempt to gather some empirical evidence. Theory is a great place to start from, but I'm a belt-and-suspenders kind of guy and awful stubborn too. This keel build is going to cost me three Soss hinges, a couple Heim joints and some aluminum tubing, and about five hours of my time. I think that makes it worth a try. As I said, if it turns out to be a big pain in the ass, then I haul the boat, center the flap, and fair everything over with a couple layers of 'glass. No big deal.

[tspeer]

What about Case 5: Boat travelling to windward
Kite pulling mostly ahead and a little sideways
Trailing edge deflected to leeward
If you can get a kite to do this, you'll have a gold mine on your hands! But I accept the premise.
So the bow of the boat is deflected to windward--right?-- and if I keep everything balanced to *just* before the keel stalls, then that should net me a greater windward moment than without a trailing edge flap.

No, the bow will be deflected to leeward. You have to consider what makes the whole system come into equilibrium so all the forces and moments are balanced.

In the wind tunnel, where you hold the board fixed in position relative to the stream, if you deflect the flap you get more lift. In order to find the angle where the lift is again zero, you have to point the leading edge down and operate the board at a negative angle of attack, so the negative lift from the angle of attack just cancels the positive lift from the flap deflection. That is known as the zero lift angle of attack.

When the board is mounted to the boat, deflecting the flap does not have the same effect as it does in the wind tunnel because the board moves the boat. Let's take something like your example, where the boat is being towed on a straight course and the boat is initially directly behind the tow. The board is producing zero lift. Now deflect the flap and maintain the heading of the boat parallel to the tow boat's heading. You will initially feel the change in lift from the flap as a lateral acceleration. Then the boat will start moving sideways.

As it does, two things happen. The sideways velocity of the boat will result in a negative angle of attack on the board, reducing the board's lift - this is known as sway damping. As the boat moves to the side, the angle of the tow will change, placing a side load on the boat.

Eventually, when everything settled down into equilibrium, the boat will be to the side and behind the tow boat, like a waterskier moving out of the wake. The angle between the towline and the centerline of the boat will be equal to the arctangent of the lift/drag ratio of the boat. The angle of attack on the board will be zero because the boat is maintaining the same heading as before, and all of the lift is coming from the flap deflection. The fore-aft component of the towline tension will be equal to the drag of the boat, and the sideways component of the towline tension will be equal to the lift from the board. But the situation will be different from the start, because now the boat is being towed to the side of the tug, not behind.

To return the boat to the original position behind the tow boat, you have to steer back, changing the heading and reducing the lift on the board. When you arrive back to a steady tow behind the tug, the bow will be pointed to the same side that the flap was deflected. The angle between the towline and the centerline of the boat will be equal to the zero lift angle of the board with the flap deflected. The lift on the board will be zero because that's what it takes to balance the zero side force from towing straight behind the tug.

When we talk about the effects of flaps on sailing performance, we're always assuming that conditions are quasi-steady and in equilibrium. But when people consider flaps or jibing boards, they often assume that the boat is fixed on its course, which is not the case. And the flap would be pointless if it were!

I understand that this is going to cost me speed due to lift-induced drag (nothing is free, my powers are many but I can't refute the laws of physics just quite yet).

No, there's not necessarily any more induced drag from the flap, if it runs the full span of the board. The total lift on the board with the flap deflected will be the same as the undeflected flap, but the leeway angle will be different. As long as the lift is distributed along the span of the board in a similar manner whether it comes from the angle of attack of the board or from deflecting the flap, the induced drag will be pretty much the same. It's only when the flap covers part of the span, thereby loading some of the board much more than the unflapped part, that the induced drag will go up.

You're forgetting that the kite can be sheeted independantly of direction of pull; I can hang the kite anywere in the wind window and keep it hovering just short of a stall, or sheet in and produce a truly impressive yank. ...

Of course, you can sheet the kite anywhere. And the leeway angle will adapt to where you fly the kite. Any time the kite is flying to the side, the leeway angle will be increased. If the kite is flying in line with the centerline, whether down low to the water or overhead, the leeway angle will be zero.

I'm going to give this a try to attempt to gather some empirical evidence. Theory is a great place to start from, but I'm a belt-and-suspenders kind of guy and awful stubborn too. ...

I suggest you put a protractor on the stern, and trail a string with a bead on it from the center of the protractor to measure the leeway angle. It'll help to have a big protractor, because for the most part the angles will be well under 10 degrees.

[eponodyne]

Ow You got math in my eye!

[brian eiland]

Lots of activity here !!...haven't had time to keep up

video I was referenced to:
Sit-down kiting (http://www.skytoys.co.nz/Kite%20videos.htm)
http://www.skytoys.co.nz/Kite%20videos.htm

[eponodyne]

Video (http://www.youtube.com/watch?v=tSWfi5AMT2E&feature=related) showing stability of a Peter Lynn kite.

This is promising, my experience with traction kites is that they have to--have to-- be flown all the time. Apparently the model shown is water-relaunchable as well.

Hmmmmm.

[Guillermo]

Very interesting that statically stable Peter Lynn's kite. Member of this forums Dave Culp has developed a long time ago also 'anchor type kites' for marine propulsion.
See: http://www.kiteship.com/

Cheers.

[brian eiland]

Either this French group has been reading my posting,

...or I've been reading their site,

...or many of us are thinking along the same lines.

... and Dave Culp was way ahead of us all

[Guillermo]

That "Trawlivarius" seems to be flying an SkySails' kite.

Cheers.

[brian eiland]

Video shot (http://www.cammas-groupama.com/en/index.jsp)

...click on "english version" and check out the competition...first a windsurfer, then a kite sailor.

[Munter]

Epo - before taking on such a big project as a 5.5m kite monohull I would strongly recommend that you learn to kitesurf. The lessons you learn there will help ensure that your design is practical and workable. It will also help you understand the dynamics of kite flying which will be important if the project is to be successful.

Cheers,

Munter.

[Guillermo]

SkySails first flight on the "Michael A."
http://s2.streamingfarm.tv/streamingfarm/skysails/20080120_Michael_A_Flugfilm_02_1000k.wmv

When 'zenithing' the kite, net propulsion force is zero. SkaySails' developers say you can use this feature to put the kite in 'stand by' mode, useful when trawling and other fishing manoeuvres.

Cheers.

[FAST FRED]

"and if I keep everything balanced to *just* before the keel stalls, then that should net me a greater windward moment than without a trailing edge flap."

Most cruisers head up till the HULL stalls , the keel on a cruiser just makes it happen at a bit higher angle.

A racer with a huge draft will sail on the keel's angle of attack , mostly as a tactical manuver , as the drag is higher with all the lifting force coming from the keel, and the hull doing little for lateral resistance.

Remember the plots of Nelson showed 90 deg tacking , and no keels as we know them today.

FF

[eponodyne]

Munter, thanks. As it stands, I have several 2- and 4-line kites and have hundreds if not thousands of hours flying them. I built a kiteboard last summer using ideas gleaned from the old zeroprestige.com site (and didn't pay attention to what they had to say about volume, this thing is way too thick and too heavy. But it sure looks sharp.), and have been out several times. I could waterski and wakeboard about the same time I learned to pee by myself so it wasn't too hard to integrate the ideas.

Fred, good point on the hull stalling. I hadn't thought of that. I wonder if I could build a kite-powered ekranoplan.....

LOL

[sigurd]

Some older references, my dinghy with a 4 line winch, and cristofa's mini 650: http://www.boatdesign.net/forums/showthread.php?t=12279&highlight=kite+dinghy

On my Tornado 20' cat I used a line with pulley between the bows instead of a track. The rudder was controlled with pedals via ropes.

This is Peter Lynn's system for launching an Arc kite on one line. As the four other lines are tightened, the first line will be slack, and the kite will fly in its normal shape.

[sigurd]

check out some older news on www.peterlynnkites.com .
He has a 6m (?) mono with a system for eliminating heeling - a bow mounted pivoting pole. He used or proposed tandem rudders to eliminate centrifugal heeling, I think.

[brian eiland]

...just saw this news from Sail-World.com, and being that it relates to 'supplemental wind power' I felt it belonged in this subject thread


Advance to the Past: Fishermen Start to use Sails

Commercial fishermen in the UK are reverting to wind power in response to soaring fuel prices, as skippers rig their boats with auxiliary sails to cut the amount of diesel they use.

The move comes as a new generation of vessels is being developed that will rely almost exclusively on sails.

Higher fuel costs threaten to force many fishermen out of business. The price of the red diesel the industry uses has doubled in less than a year, while fish prices have remained relatively stable.

Deas, chief executive of the National Federation of Fishermen's Organisations, said a number of skippers were now using sail power to help them travel the long distances between port and their fishing grounds.

'Skippers are putting on foresails while steaming to fishing grounds offshore,' he said. 'The whole cost structure of the industry has shifted so dramatically as a result of fuel price rises, and in response, vessels are looking at what they can do to reduce costs.

'Fleets are going to have to find ways of reducing fuel dependency. Everyone is looking for the optimum steaming speed and people are looking at a whole range of measures, including sail.'

Auxiliary sails were once commonly used by fishermen to pick up extra speed, but they died out in the 1980s as engines became more powerful. 'These sails might sound a bit Heath Robinson and a bit of a throwback, but in other ways they are the future,' Mr Deas added. 'We used to have windmills in this country. Now we are building windfarms.'

At the wheel of his boat, the 36ft Sardia Louise, Roly Kirby, a fisherman from Helford River, Cornwall, said he had saved up to a fifth of his weekly fuel bill since fitting a sail to the 20ft mast. He uses the sail while steaming to and from fishing grounds up to 20 miles from his home port, where he lays nets for monkfish.

'We are steaming for about three hours out and three hours back every day, but with the sail, we can cut the revolutions back on the engine from about 1,300 to 900 and still make the same speed,' he said.

Mr Kirby, 33, steamed along the sheltered Helford River while crewmate Perry Roger, 28, tied a spinnaker sail to a mast at the bow. Once out into Falmouth Bay, the potent northwesterly filled the sail and the throttle was eased back to save on fuel as the Sardia Louise stormed towards the Lizard.

'We have been using another sail, which is bigger, but this one seems to be doing the job today,' said Mr Kirby. 'You have to be careful in case the wind is too strong for the sail, but in these waters it just gives you the right helping hand.' Since October last year, the cost of red diesel has risen from 30p to 60p a litre, and Mr Kirby now spends about £1,000 a week on fuel. It is his biggest single expense and means that after paying wages, insurance and leasing a quota, he must catch fish worth at least £6,000 every week to make a profit. 'The fuel prices are terrifying, so the savings I can make are a real boost,' he added.

'Of course, it depends on the direction and strength of the wind, but these are pretty good results using an old spinnaker from a racing yacht on a traditionally built fishing boat. It looks like the future. I'm sure this will catch on more and more.'

Kevin Bennetts, a former fisherman who now runs an oil firm selling diesel to fishermen in Cornwall, said: 'A lot of people are dragging old bits of sails out of their lofts and hoisting them up. It can make a difference, supplementing the engine.'

Although the use of sail is currently limited to small and medium-sized boats, there are plans to harness the power of the wind for Britain's biggest and most powerful fishing boats, such as beam trawlers, which use up to £12,000-worth of fuel a week.

A German company is developing a system that would allow larger trawlers to be powered by a computer-controlled kite flying off their bows. The technology is already used on two cargo ships and can provide up to 35 per cent of their power.

In a separate development, an Essex boatyard is developing a new generation of sailing vessels for fishermen. Gemini Workboats in Colchester has designed a 30ft catamaran which uses its small, 14-horsepower engine only to enter and leave harbour and in emergencies. Boats of a similar size would normally require an engine of about 200bhp and would use around £600 of fuel during a week's fishing.

Plans for the catamaran, which will cost about £60,000, are to be announced this week, and work on the first boat is expected to start in October. Although it would not be suitable for trawling, the vessel could be used for laying nets and pots and for trolling - dragging baited lines behind the boat. Andrew Craig, of the company, said: 'This is the first boat of its kind really since the 1930s. But it is time to go back to them. They are cheap to build and cheap to run. We think there will be huge demand. Sailing's time has come again.'

by Jaspar Copping, Telegraph/Sail-World (http://www.sail-world.com/cruising/index.cfm?nid=46669&rid=11)
_________________________________________________
Of course I've tried promoting the idea of 'Sportfishing Under Sail' for quite some time:

...and at one point I commented, "Several times I’ve put this idea into hibernation, particularly the ‘Gamefishing Under Sail’ (http://www.runningtideyachts.com/gamefishing/)idea. My comment at the time was something like, “I just spent 18 years in the sailboat business trying to convince sailors of the virtues of multihulls, and now I’m going to try and sell a fishing guy a boat with sails on it. I’ve got to be crazy!” :rolleyes:
http://www.boatdesign.net/forums/showpost.php?p=32941&postcount=3

http://www.runningtideyachts.com/gamefishing/

[masalai]

Slowly, the world is getting there.... One can only hope that the changeover is more expeditious than the supply of diesel expiring....

[Guillermo]

A further 'step to the past': This week the Kathleen & May, a 108-year-old triple-masted wooden ship arrives in Dublin carrying a cargo of 30,000 bottles of French wine. :)

http://winebysail.canalblog.com/

Cheers...(hic!) :D

[Guillermo]

Dan Tracy's kite propulsion system (we have seen videos from his tests not that long ago at this forums) has now gone into commercial stage for vessels under 40 feet in length. See: http://www.kiteforsail.com/

Cheers.

[Fanie]

I like the idea of using kites more than using sails. For one you get rid of the bulky mast, stays and a lot of clutter.

My friend has one of these fancy kites, you can fly it any direction you like including to windward, and may even be better than sails.

I have read some previous comments on the use of kites, and I was wondering how easy they would be to control to fly in the direction you want.

My friend's kite has two handles, by twisting either up or down with the wrist you can control the height and direction of it. This could be done with electric motors, but how to sense the action of the kite for control feedback, and how to deploy and reef such a big kite is another question.

If a sensable way of doing this can be found the size can be even larger than sails, make more power and have better windward performance.

Sure beats rowing good grief :D

The kite will also have the added advantage of adding lift

[Fanie]

Eh come on guys, my arms are numb. Who'se turn is it to fly the kite :D

[juiceclark]

Thinking about this lately, I envision the dinghy davit center mounted on the foredeck just in front of the cabin windows on a large, sportfishing style vessel. With a non-free-spooling windlass at the bow, you run that anchor line through a pully in the davit. With the davit fully extended and pointed straight-up, you release the sail...letting line out with the foot controls at the windlass.

So, what's the start-up expense? You already have big dollars in a nice windlass and even more in a nice davit. Buy a sail and hope the wind blows in the direction you're headed...would make for a fun trip!

TC

[Greenseas2]

Shades of the clipper ships. The old square riggers flew kites from several masts only they were more closely tethered, but the bottom of square sails were loosely secured by lines which could be set to take advantage of wind direction. The top gallants and top royal sails were definitely kites. I would seem that some good information on modern day kites can be gotten from the whaling museum in New Bedford, Mass and other museum dedicated to tall ships around the world. After all, some of these ships did set some long distance speed records.

[Greenseas2]

Shades of the clipper ships. The old square riggers flew kites from several masts only they were more closely tethered, but the bottom of square sails were loosely secured by lines which could be set to take advantage of wind direction. The top gallants and top royal sails were definitely kites. It would seem that some good information on modern day kites can be gotten from the whaling museum in New Bedford, Mass and other museum dedicated to tall ships around the world. After all, some of these ships did set some long distance speed records.

[brian eiland]

...carrying a cargo of 30,000 bottles of French wine. Cheers...(hic!)
I don't know about flying a big kite while drinking the cargo of wine....:rolleyes: :D

[brian eiland]

Thinking about this lately, I envision the dinghy davit center mounted on the foredeck just in front of the cabin windows on a large, sportfishing style vessel. With a non-free-spooling windlass at the bow, you run that anchor line through a pully in the davit. With the davit fully extended and pointed straight-up, you release the sail...letting line out with the foot controls at the windlass.

So, what's the start-up expense? You already have big dollars in a nice windlass and even more in a nice davit. Buy a sail and hope the wind blows in the direction you're headed...would make for a fun trip!
Something like this?....
....kite assisted fishing cat
http://www.boatdesign.net/forums/showthread.php?t=20319

....with this athwartships fishing deck
http://www.yachtforums.com/forums/general-sailing-discussion/1548-gamefishing-sail-under-sail-power-4.html

[eponodyne]

The kite will also have the added advantage of adding lift
I like that you like kites!! Let's like each other.

Anyway, it just occurred to me that weight is weight no matter if it's carried by the hull or by a kite. I wonder how the kite picking up some of the mass burden translates into performance decrease. Anybody with a 12-pound brain want to take this on?

[juiceclark]

[QUOTE=brian eiland;217801]Something like this?....
....kite assisted fishing cat
http://www.boatdesign.net/forums/showthread.php?t=20319
===========================

Exactly! Brian, you're really prepared to run with that design. Is there a large production firm out there today who has a clue to mass produce and market such a design? The "Offshore Sailing School" (http://www.offshore-sailing.com/) is next to my office here in Sw FL and the owner says they are the busiest ever in 20 years. Apparently, many of his newest students are retirees who currently own 35 - 60 foot cruising yachts who are now ready to give sailing a try.

As I've mentioned too many times, I'm partial toward mono-hulls. Of course, I'm thinking about the sail application to the 50' sportfish I'm building. With a 17' beam, this boat is comfortable for cruising, gunkholing, etc....rather than a knife to run out to the canyon and back. The Kite would work great...especially with thrusters to help make up for a tiny keel.

We are all striving to create the best all-around vessel. A little sailing, little fishing, offshore and intercoastal cruising, cocktail parties....customers should be able to do it all. To do so, we need stability offshore and the ability to sail, plane, utilize hybrid power for slow cruising and all while watching the Playboy channel via satellite.

TC

[brian eiland]

Exactly! Brian, you're really prepared to run with that design. Is there a large production firm out there today who has a clue to mass produce and market such a design?
Actually I have an older sportfishing guy who wants a vessel he can fish with and his son is a committed oceanography prof...need to combine the two subjects. But need some more funds committed to Oceanographic Research to help share the cost of a new build.

Years ago I wanted to get involved with Ocean studies, but there was no money available then either...so I ended up in nuclear sub stuff for the defense industry.

I'm not excited about any 'production run' of any boat below 60 feet at this point in our economy.


The "Offshore Sailing School" (http://www.offshore-sailing.com/) is next to my office here in Sw FL and the owner says they are the busiest ever in 20 years. Apparently, many of his newest students are retirees who currently own 35 - 60 foot cruising yachts who are now ready to give sailing a try.
That's interesting

As I've mentioned too many times, I'm partial toward mono-hulls. Of course, I'm thinking about the sail application to the 50' sportfish I'm building. With a 17' beam, this boat is comfortable for cruising, gunkholing, etc....rather than a knife to run out to the canyon and back. The Kite would work great...especially with thrusters to help make up for a tiny keel.
The kite is just an assist or slow propulsion for those long trips that you are not worried about speed, and/or, you are concerned about total fuel capacity to make a certain trip. I wouldn't be concerned about a 'keel' for the kite boat, nor thrusters.

We are all striving to create the best all-around vessel. A little sailing, little fishing, offshore and intercoastal cruising, cocktail parties....customers should be able to do it all. To do so, we need stability offshore and the ability to sail, plane, utilize hybrid power for slow cruising and all while watching the Playboy channel via satellite.
Best of luck to your search for this vessel. BTW, have you given consideration to a used vessel and doing a few mods?

[JustinHale]

I just joined this forum, and I am thrilled to find that a lot of others are thinking about the same kinds of ideas as I. I was sure others were ahead of me, but my concern that it might be hard to find such minds now seems a little naive.

I've been dreaming of a tri-hull, designed like a sailboat to minimize power requirements and without any ambitions of going super-fast like a muscle-boat, but unashamed of cruising long distances propelled by its brushless electric motors, with batteries continuously charging from solar panels and wind-turbine generators. But it would also be capable of cruising long distances using sail power, having a modest mast/sails rig, enough to move it right along in stiff winds, as well as kite propulsion. It remains to be seen which propulsion would be employed the most, but the idea of always having non-petrol backup propulsion is very appealing.

Whenever I watch kitesurfing in action, I cannot help thinking that some of that could be applied to moving larger, more comfortable craft. So at one point I constructed some small, somewhat crude imitations of those kitesurfing kites, and had some fun fooling around flying them at the beach, and imagining bigger versions driving my boat, like they drive the kitesurfers, except without the wave-jumping and whatnot. So my kites have 4 control lines, 2 on each end of the kite, attached to 2 sticks serving as handles. Controlling the kites, flying them around, is more fun than video games. I tried to experiment with exploring the wind-window that some of the kitesurfing sites talk about a little bit. You can turn the kite sideways and drive it quite a ways upwind, but when you get up there and can't go any further, it's not pulling very hard anymore, nothing like it does when you're zooming across from one side of the wind window to the other.

But I guess I'm kind of a dope on this, because I still haven't reached an understanding of how such a kite, especially when oriented sideways, compares with sails on a boat flown from its mast. It would seem that not being constrained to a mast should be an advantage for the kite, on all tacks, but from my observations it seems like the kites are at their best when reaching, and that's what kitesurfers do the most of, just like windsurfers.

I can see how a single-string kite attached to a boat would be good for broad-reaching to running in a stiff wind, and I've viewed the pics on the kitesail website, but I suspect that a 4-string kite has greater potential to become the main power source for a boat on all tacks. I'm suffering from a great deal of ignorance; for one thing I have not tried kitesurfing myself. But I bet some people in this forum have.

[brian eiland]

I just joined this forum, and I am thrilled to find that a lot of others are thinking about the same kinds of ideas as I.
Welcome to the forum Justin.

You might also pay occasional visits to this other one as well.
http://www.yachtforums.com/forums/general-yachting-discussion/8127-new-age-trawler-motorsailer-kite-assisted-poweryacht.html
I try to cross post some of the submissions as there are those members of one or the other forums that don't visit each other, yet have interesting submissions to make

[juiceclark]

Brian,
The guy who owns the local windsurfing shop is a friend of mine and likes to tinker with stuff. We've been meaning to experiment with something on my F-36 Trojan but the damn boat doesn't have a davit. So, we were gonna rig something from the bridge...not sure how. I'll have to replace the windlass rode as well to experiment with a small kite...something lighter. If I had a windlass with a horizontal capstan, it could be done manually without worrying about being taken swimming....but I don't.

http://i246.photobucket.com/albums/gg120/juiceclark/IMG_0590.jpg

http://i246.photobucket.com/albums/gg120/juiceclark/CHorseNew-1.jpg

[eponodyne]

Brian,
The guy who owns the local windsurfing shop is a friend of mine and likes to tinker with stuff. We've been meaning to experiment with something on my F-36 Trojan but the damn boat doesn't have a davit. So, we were gonna rig something from the bridge...not sure how. I'll have to replace the windlass rode as well to experiment with a small kite...something lighter. If I had a windlass with a horizontal capstan, it could be done manually without worrying about being taken swimming....but I don't.

http://i246.photobucket.com/albums/gg120/juiceclark/IMG_0590.jpg

http://i246.photobucket.com/albums/gg120/juiceclark/CHorseNew-1.jpg

If I were you... and I'm not... but if I were you, I'd install a big husky pad-eye just forward of the mast. A good Christian piece of equipment that can take a serious pull (you may find it useful for other things in the future, as well) and just use that as the attach point for the chicken loop on the kiteboard rig. Bend on a couple 1/2" lines, one to each end of the bar, and lead them back to the cockpit, so you can sit down in comfort while you fly the kite. I'd leave the sheeting loop all the way out and fly the kite depowered until you're sure you know what you're doing and wish to sheet in a little more.


I assume you have 30 foot or so of surplus half-inch (or thereabouts) nylon.
Shouldn't cost you much more than a hundred bucks for the padeye, installed. Maybe ten more for a nice stainless shackle.

[juiceclark]

Brian and Epo,

Thanks for reminding me of this subject. I stopped by the surf shop on the way home for lunch and he just happened to have a 20 meter kite sail a guy just traded in for a new design...couple hundred bucks out the door. It looks like this but without the hideous graphics:
http://www.kite-line.com/kiteboarding/kitesDetails.php?i=1342

I'll have a lot of fun this weekend playing...can't wait to get people watching then put the engines into gear. I'll be running 18k on a plane with sail up just to freak out the blue hairs.
Epo is right...I'll have to install some type of eye or pulley mid-boat. Then I'll sit at the bow to release and retrieve the 100' of superlight 5/8th" line I just bought. I'll take some pics and post. Please call the CG if you don't hear from me by Tuesday!

If this works out well, we'll try my neighbor's 48' powercat next with this type of deal:
http://www.kit-cats.com/kite/KiteSailPowerboats.htm

[brian eiland]

...Epo is right...I'll have to install some type of eye or pulley mid-boat. Then I'll sit at the bow to release and retrieve the 100' of superlight 5/8th" line I just bought. I'll take some pics and post. Please call the CG if you don't hear from me by Tuesday!
Brian wrote: Don't understand your need to 'anchor' your pulling point at mid-boat...why not at the bow??
http://www.skysails.info/index.php?id=8&L=1

http://www.skysails.info/index.php?id=46&L=1
Force Transmission Point (tow point)
The "force transmission point" - also called "tow point" - is the point at which the towing rope of the kite is connected to the ship.

The tow point guarantees the optimal alignment of the kite's power for every course and wind direction.

The tractive force of the SkySails-System is directed to the bow area over the force transmission or tow point mounted on the foredeck. Generally the existing ship's structures are sufficiently dimensioned, since that is where the capstan and anchor windlass are also housed. The power transmitted by the SkySails-System is comparable to that of an ocean-going tug. An appropriate stability computation is made for each vessel prior to the installation of a SkySails propulsion.


Brian wrote: It's the winch and tower for inflating the kite that are located further aft to facilitate the inflation of the kite over the foredeck rather than out over the front of the bow

Winch
The SkySails towing kite is recovered and launched using a dynamically operating winch, which also serves as rope storage. The tractive force measurement is pre-installed in the winch. The winch speed is chosen so that the towing kite can be stabilized at any time.

Launch and recovery system
The launch and recovery system manages the deployment and lowering of the towing kite and is installed on the forecastle. During launch a telescopic mast lifts the towing kite, which is reefed like an accordion, from its storage compartment. At sufficient height the towing kite then unfurls to its full size and can be launched. A winch releases the towing rope until operating altitude has been reached. The recovery process is performed in reverse order.

[juiceclark]

I figured if the "force transmission point" was right at the bow it would have a levered action in pulling the bow around. Further after, say just in front of the salon windows, would eliminate some of that. But as you know I'm a finance guy not a naval engineer! If I want to go to 12 o'clock and the wind is blowing 2 o'clock, wouldn't it be easier to keep my heading with the connection further aft?

If I can just connect this thing at the bow it's a no-brainer! There are all kinds of cleats with an eye in the middle and other things already up there to use. I have fairly sizable rudders and some keel to stay on course. Is that enough or am I way off course?

[eponodyne]

I figured if the "force transmission point" was right at the bow it would have a levered action in pulling the bow around. Further after, say just in front of the salon windows, would eliminate some of that. But as you know I'm a finance guy not a naval engineer! If I want to go to 12 o'clock and the wind is blowing 2 o'clock, wouldn't it be easier to keep my heading with the connection further aft?

If I can just connect this thing at the bow it's a no-brainer! There are all kinds of cleats with an eye in the middle and other things already up there to use. I have fairly sizable rudders and some keel to stay on course. Is that enough or am I way off course?

I really don't think it's going to be, on a moment that long. I'd really think you want to keep your load centered around the mast, which should be about, what, 4 feet forward of the LCP for your existing sail plan? Something like hat? Anyway, I really don't think you want to try to fly the kite off the bow. I really don't.

[juiceclark]

Agreed. I'll attach the kite at a point near the salon window...probably about 5 feet fore of center. With a relatively puny 20m kite I can stand anywhere on the bow to mess with it. If it seems steady at a certain height, I'll go back to the flybridge to see how everything reacts.
TC

[eponodyne]

Well, if you can find a breeze in South Florida in August, the 20 should be able to deal with it. If the wind pipes up, that kite might just kick your ass. That's 200 square feet developing 3-6 pounds of lift per square foot; and it goes up as the windspeed goes up.

Have you flown kites before? Like stunt kites and traction kites and like that? I cannot stress enough that you spend a lot of time--like a hundred hours or so-- just flying kite in the park or at the beach. If you have done this, then you'll understand my caveats; please forgive me. If you haven't, be aware people have been killed playing with big kites. They're a lot of fun but you need to know what you're doing.

[Fanie]

My friend has a 1.5m stunt kite I flowed once. In wind like in 'it blowing now' you have to hold on well to this thing. Good way of getting rid of children :D

[Munter]

Brian and Epo,

Thanks for reminding me of this subject. I stopped by the surf shop on the way home for lunch and he just happened to have a 20 meter kite sail a guy just traded in for a new design...couple hundred bucks out the door. It looks like this but without the hideous graphics:
http://www.kite-line.com/kiteboarding/kitesDetails.php?i=1342

If this works out well, we'll try my neighbor's 48' powercat next with this type of deal:
http://www.kit-cats.com/kite/KiteSailPowerboats.htm

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

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

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

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

[juiceclark]

Munter,
You are quite correct. These older style kites have been way outdone by the newer technology in bow kites. You can get a bow kite's edge up easily to relaunch, the relevant working area is much larger, etc. That's why you can buy one of these for a couple hundred bucks and the new ones are 10X that amount.

But it doesn't matter anyway. I have a 22,000 pound boat (actually 22,222 with me aboard) and I'm just going to fool around with different ways to run the lines and float her up there. This little kite won't give me 2 knots on a good day. After I get it figured out a bit, I'll consider a 60 meter kite for real.

Epo and Fanie,
Thanks for your concern...should be fine. Kites are just like women...keep them tied down, be careful with your fingers and, mostly, know when to let go!

[brian eiland]

...was doing a bit of research back thru some older subject threads, and ran across this from 2004:

Return of sails in era of expensive oil, enviro. regs?
http://www.boatdesign.net/forums/showthread.php?p=32836#post32836

...how history repeats itself, and often we don't learn enough from it

[eponodyne]

I note Juiceclark hasn't posted in a couple weeks. I hope he's OK, and an errant kiteline didn't amputate a hand or something.

[juiceclark]

Shoot...I'm so fat that kite didn't have a chance! Everytime I fly that big kite for awhile I become more aware of the fact that a rigid frame kite has nothing to do with flying a kite attached to a boat! It's a lot of fun though...might actually try it on a board or in a kayak sometime soon.

The blow-up/rigid part of my kite makes it very steerable. Being a complete sailkiting novice, I was still able to figure out the idiosycrasies of flying that 20m deal in about 15 minutes. There was a light but constant 7 - 10mph the day I first tried...perfect for gentle learning. It was easy to see that a rigid kite will not fly unless someone is actively flying it! You have to constantly move the bar about and tug and release to get it pulling in the right direction...you have actually fly it.

Had I sewn a big sail out of bedsheets it probably would have worked better than a rigid edged kitesail! So, anyone know of a nice spinnaker for sale?

TC

[kach22i]

http://clicked.msnbc.msn.com/archive/2008/01.aspx
http://www.telegraph.co.uk/earth/graphics/2008/01/20/eakite120big.jpg

[masalai]

Nice concept, but for yachts the problem is the "controller" as to be effective, the wing must be continuously flown in a sort of "figure 8" pattern & the other issue is the 3 to 500 flexible cable to take the loads and to have a winch that could draw it down under power so the radio control and power supply in the control pod does not get immersed (fall in the water).....

[Hacklebellyfin]

Hi,

I hope you are all doing well.

I joined this forum because i felt in love with the idea of sailing a boat with a kite.:p

Now I do have some questions about Kite boating:

ferrocement (concrete is so cheap:) )+ kite?

Multihull +kite?

Indonesian pinisi+kite?

What is wrong with the winch as seen in this hawaiIan tv news Video?:
qnACybMhPs4

What do you think about Stephanie Krucke design?:
http://princessofstyle.net/pdf/KITANOwebview.pdf

[Fanie]

If you can find an easy way to do the control and handle the kite then the kite is an option.

Would be a real pleasure not having to worry about masts and stay's...

[eponodyne]

If you can find an easy way to do the control and handle the kite then the kite is an option.

Would be a real pleasure not having to worry about masts and stay's...
I'm sketching out an alternative design, involving a Harken traveller car and track. In a nutshell, the kite control bar is mounted to the car, and then there are "tiller lines" running to a steering wheel in the cockpit. Steering the boat is with rudder pedals, perhaps a whipstaff. With my current thinking running toward a catamaran or tri with a small center hull, I realized it's entirely possible to cruise with the leeward hull flying! How cool would that be?

[masalai]

You still have to ACTIVELY fly the kite.....

[Hacklebellyfin]

automatic winch:

mechanic:
rotative base >hydraulic
short mast>hydraulic

Electricity:
hydraulic compressor> solar panels

Navigation
electronic weather cocks
connected to
laser scanning the wind window, positioning the kite on computer and sending orders to hydraulics...
:rolleyes:

Better:

A level ruler fixed to the kite rig, tuned to best angle.

When bubbles reach an end of their own tubes where sensors are fixed
it sends impulsions trough a wire fixed along the rope down to the computer that gives order to hydraulics.

:cool:
:D

[masalai]

automatic winch: = lotsamoney :D

mechanic: = lotsamoney :D:D

Electricity: = lotsamoney :D:D:D

Navigation = Too complex & even more money:P:P:P:P

[FAST FRED]

I can understand why a cargo ship might try a kite to reduce fuel consumption a few percent , but why would someone pass up on a genuine motor sailor , with known abilities far superior to a kite ?

Simply the extra volume of a big trawler box of a boat , or the claimed extra work of a boat that genuinely sails?

FF

[Fanie]

Hi Fred,

There could be a few advantages to a kite, my opinion.

No mast, no stays, no rigging,
-and so less structural compensation required.
May not be as limited in size.
Can fly high, in better wind than on the water surface.
Single control unit.
Should be able to fly to windward as well as any sail.
Has a lifting effect on the vessel, heeling over may become less of a problem.

If a sensable way to launch and retreive and fly the kite can be found then most of the problems are solved. Such a setup may well be less costly than the conventional sail setup too.

[masalai]

Yep, there COULD be advantages, but the product is not fully able to be applied to smaller recreational boats YET....

[Hacklebellyfin]

Thanks Fanie.

And isn't our duty to share infos , open new views ??

Am i born a hundred years too early?

Any constructive comments to get that kiteboating for small vessels thread going in the right way?

[Fanie]

Yep, there COULD be advantages, but the product is not fully able to be applied to smaller recreational boats YET....
Since we are boys, we can play with toys. Nice challenge to get it figured and tried out eh ;)

And isn't our duty to share infos , open new views ??
No, whatever is shared is out of free will. There is such a thing as intellectual property.

Am i born a hundred years too early?
I don't know. What does your mother say ? :D

Any constructive comments to get that kiteboating for small vessels thread going in the right way?
Who knows. If we can get the available resources ie hydrogen or nuclear propulsion right we would probably give the kites back to school children to play with.

[eponodyne]

You still have to ACTIVELY fly the kite.....Yes you do. And in a... "mastboat", I guess, let me just coin the term here and now LOL... you still have to trim the sails. Oh sure ;in the trades if you're not looking to get that last 1/10th of a knot out of her you might leave the sails alone for hours (or even days); but honestly, in a daysailer, on a pleasant afternoon, how much fiddling with the sail/sheet/boom/bowsprout will you do? Isn't part of the fun pulling on all the strings?

[Fanie]

You still have to ACTIVELY fly the kite.....
And can I suggest a decent harness to keep your ugly bum from being plucked off the boat :D

Mmmm... I just had a not her one of my brr-ain waves. Since the kites in the pictures have a control pod to make it look more complicated, you can use the same kite to catch fish with.
Here's how -
Get the kite up
Get hooked into a big one
Attach kite to line.
Fight fish with kite via rf link to pod
Fish tired, fly kite to boat.
Send wife to get fish aboard so she can clean and cook it
You pour a stiff one to get in the mood for dinner / supper / whatever.

If you lose a fish you can always blame the software ;)

Oh damn, you don't need a boat to fish this way :D At least the city yappies can also fish now without getting too physical :rolleyes:

[masalai]

Sorry Fanie, but it is already being done, the problem is waiting for an offshore breeze to take the lure/baited hook offshore. In a similar situation, use CHEAP party baloons to carry the baited hook/lure a suitable distance offshore. :D:D:D

If you are boating and wish to troll the lure closer to a reef edge than you are willing to run in your boat then attach a short plank with weights to keep it vertical and a little "hand flag" mounted for visibility and tied back to a point so the plank tracks off to one side.... (do you need a diagram?)

[Fanie]

Yes pleas Mas. A detailed drawing should help.

We actually use another technique in such situations. It's called casting :D

[masalai]

Fanie, How is that for brainfarts?

[catmando2]

If this works out well, we'll try my neighbor's 48' powercat next with this type of deal:
http://www.kit-cats.com/kite/KiteSailPowerboats.htm

I will be very interested to see how that goes as I am again looking at this option for my 50ft cat that I am building.

How do you think it will go with the fixed blade props?

Dave

[FAST FRED]

How do you think it will go with the fixed blade props?

How does any sail boat go with 2 sea anchors being dragged behind ?

FF

[Fanie]

How does any sail boat go with 2 sea anchors being dragged behind
You may no get on the plane, Fred :D

[Fanie]

Hi Mas, ever since you bacame grumpy grampa you cad has deteriorated something terrible :( You have to take extra classes especially before you start your own boat :D

[masalai]

I thought a quick sketch and scan to get it to you before you had a chance to turn your computer off on your way out to go fishing? and as you can read in another thread??? my main toy is down still with motherboard/ram ? defects in manufacture still......... and am using backup notebook with minimal grunt to work up any CAD package.... and I have been in "withdrawal" soo long I have forgotten how to do cad - - - U know - part of the ageing process - the memory fileing system gets corrupted by distractions like boats, booze and sex....

[eponodyne]

the memory fileing system gets corrupted by distractions like boats, booze and sex....THESE THINGS ARE NOT "DISTRACTIONS!" THESE THINGS ARE THE MAIN EVENT!!!!!

[masalai]

Ok, - - - - their importance starts to over-ride all other considerations in a desperate bid to fulfull ones destiny, to have fun, and procreate, as much as possible - as one gets older one becomes more desperate to "cram it all in".....

[brian eiland]

...saw this discussion on another forum...

What I am curious about however was your comment that the boat really needed a fair bit of breeze before the kite could be flown by amateurs (sorry, pros) .

Is this a design flaw ? in the kite or the crew ? inherent in the nature of the beast or what ?

Should I not be able to leave the Cape Verdes, put it up and just keep an eye open for St Lucia on the horizon ?

That appears to be more of less what the Germans(edited) are claiming for that odd half spinnaker half parachute thingie.

Enquiring minds would like to know
Pretty much what I expected, too. Figured if I didn't go, they might fly it and stuff it up even worse (would have been difficult), with no one there to give the other side of the story.

Outleaders need about 8 knots apparent to fly. This is often available up high, but not at alunch height. Once you know how to fly them, it is possible to launch them on more of a reach, which allows the apparent to work in your favour. However, until you get to this stage, it is much easier to launch and fly them downwind, when apparent works against you.

As long as the kite always saw 8 knots apparent within 30 degrees either side of ddw, you could hoist it at Cape Verdes, cleat the lines and not worry about it until the other side. What I like about it for shorthanded sailing/racing is that, although it is more likely to fall in the water if the wind changes, it is unlikely to do any harm, just being towed along by the retrieval line (shorter than the flying lines) until you wake up and re hoist it. This compares with a caught aback and/or flogging spinnaker, with the potential to drop the mast and/or capsize the boat.

Remember that these are first generation kites and there is still a lot to learn, particularly about launching them, line handling ( I have a water driven line retriever which works pretty well) and retrieval. They weigh considerably less than a spi, but are heavier than necessary for light air, when a gossamer version with windsurfer kite lines would fly in lighter air. The lines and kite at present are sized to lift the boat out of the water, which is extreme. Given that the drag of the lines is the biggest performance inhibitor, then lighter lines will make a big difference.

If you can organise a J24 or similar sized boat, I will bring my 40 sqm across to Sydney next time I visit (or anywhere else I happen to be visiting) and show you how it works.
regards

rob

[rob denney]

G'day,

I posted the above after an abortive attempt to fly an Outleader kite on an 80'ter in this years Sydney Hobart. The abort was nothing to do with the kite.

The offer at the end applies to anyone who is interested in kite technology.

Also, if anyone has any questions on kite powered boats, I am hapy to try and answer them.

regards,

rob

[brian eiland]

There are a few other 'kite' discussions over here, postings #161 thru #165... (http://www.boatdesign.net/forums/motorsailers/monohull-verses-multihull-powersailers-motorsailers-4499-11.html)
...including
Just got a reply from Kit cats in regard to their kite sail and even suggested they join the kitesail discussion here.
Reply to the email
Thank you for your inquiry.
We no longer deal in the kite sail. We removed it from our website
many months ago.

Strange, I was just looking at it.Yep, still there
http://www.kit-cats.com/kite/KiteSailPowerboats.htm

http://www.kit-cats.com/kite/300%20meter%20kite%20sail.htm

[eponodyne]

Wow, they sure gave up fast.

[masalai]

backwards it seems as the sites are still open....

[brian eiland]

Here's a interesting digression

So this Dutch artist has created a beautiful propeller-driven skin-on-frame trimaran that only goes directly upwind, without human crew, and set it underway in the western Pacific.

A fascinating project; be sure to check out the construction photos. Some interesting ideas, to be sure, and good for her for actually getting the thing built and launched.

Sailing Directly to Windward (http://www.boatdesign.net/forums/boat-design/sailing-directly-windward-27000.html)

[peter radclyffe]

Here's a interesting digression

So this Dutch artist has created a beautiful propeller-driven skin-on-frame trimaran that only goes directly upwind, without human crew, and set it underway in the western Pacific.

A fascinating project; be sure to check out the construction photos. Some interesting ideas, to be sure, and good for her for actually getting the thing built and launched.

Sailing Directly to Windward (http://www.boatdesign.net/forums/boat-design/sailing-directly-windward-27000.html)
which materials cause the least environmental damage to produce for boatbuilding

[brian eiland]

Yes Peter,
Take note that in my original posting #1, quote "Light-weight construction would be desirable but not necessary. Third world hull construction materials are a possibility."

I was hinting at saturated wood epoxy, and/or cold molding wood constructions, as opposed to hi-tech sandwich composites.

[masalai]

brian eiland, Thanks for the link, a very interesting project (a bit whimsical?) but one worthy of bookmarking and following exery-so-often.... I would like to see one that sailed "directly downwind" till it bumped into something then reverses to sail directly up-wind till it bumped into something again, but travelled quite slowly?

[diverdon]

I have always been a power boater so I know little in regard to sailing so please forgive me if my suggestion seems either dumb or self serving. (It is defiantly self serving because I am one of the owners of the company that manufactures the product I am going to ask you to look at)

From my child hood kite flying it always seemed that the hard thing to do was to get the kite properly launched through the still or gusty air near the surface. I have to imaging that even with these kits launching them can be a problem. There must be many occasions where the air aloft would be suitable for use but the kite is not used because the launch or recovery conditions are difficult.

http://www.buffaloturbine.com/hydraulic.htm I make a turbine blower which can produce a controllable, variable, steerable air stream of up to 185MPH at 10,500 CFM. I wonder how useful a device like this would be in launching or recovering a kite.

[masalai]

:D:D:D nice try, but on a recreational boat not justifiable on cost or weight or extra energy requirements, there are several threads on using "kite" systems on recreational and large commercial vessels - the larger cargo boats have semi-automatic launch and retrieval and use when conditions are favourable - control systems are rather complex...

For recreational sailing craft - a fun toy but difficult to control on cruising yachts as the "para-sail" is usually flown in a figure 8 pattern to maximise performance, particularly more-so if seeking a bit more upwind benefit...

Your product could be great fun as a promotional gimmick - holding a large beach ball aloft to attract attention... - PS do not do that again as "free advertising/promotion" is frowned upon :D:D:D

[brian eiland]

Hey Masalai,
I wouldn't be so quick to blow this idea off. It's entirely possible that some sort of directed airstream might be very helpful with the initial filling of the kite itself and the launching of it in certain conditions...maybe not a system as strong as Diverdon suggest, but lets not discourage new thought processes here.

[masalai]

OK, but I still feel there are issues for recreational use, as with automatic systems controls.... (to satisfy my needs - that is), but I did not intend to detract from any potential, just I do not see it yet... :D:D:D:D

[diverdon]

Masalai, I have been reading these forums a long time and generally things seem pretty civil compared to a couple of other forums I am on. I posted this because I thought the idea might be of some interest to some people. If it is not practical in your application then you should not use it.

I thought that it would be better to disclose my interest in the manufacture up front rather than let the idea "gain traction" then be found out later and accused of shameless self promotion. Still I found your comment "- PS do not do that again as "free advertising/promotion" is frowned upon " rather stinging.

I clicked on your name and I do not see that you are any kind of a moderator, or a owner of this board. So this leaves me to wonder what is your grounds for telling me what I may or may not post? What authority do you have in this matter?

With that said, I can certainly appreciate that a blower like mine is not useful to you for all the reasons you mentioned, you may not need it, the installation cost may be to high for you, the weight/size may be to much for your craft. Indeed I do not question you on any of those issues.

Brian, thank you for your comment: Hey Masalai,
I wouldn't be so quick to blow this idea off. It's entirely possible that some sort of directed airstream might be very helpful with the initial filling of the kite itself and the launching of it in certain conditions...maybe not a system as strong as Diverdon suggest, but lets not discourage new thought processes here.

In my initial post I tried to describe the maximum strength of my blower I also stated that it is "controllable, variable, steerable" thus with my unit you could use the wireless remote to control the velocity and direction of the air stream. At the risk of angering Malasai I make both gasoline, diesel, electric, PTO and hydraulic powered units. But, the wireless remote throttle currently is only available for the engine powered units. Of course with any unit the power is under control of the user. The user would have to consider the best power source to use in his individual application. If hydraulic or electric then he might wish to place a control valve or rheostat in a location convenient to the user. Regarding the amount of hydraulic power required it takes about a 20 HP input to get the volume and pressure required to make a 185MPH at 10,500 CFM, so if you think your requirement would be less than that you may be able to get away with 5-10HP.

Brian should you desire to give this any further thought I do have a stocking dealer not far from you.

G.L. Cornell Company

16031 Industrial Drive

Gaithersburg, MD 20898-7995

800 492 1373 x 3034

Attn: Bill Brown


Anyone else who like Masalai is offended by my shameless self promotion (as well as any moderators who might be considering my posting to be spam) may be happier considering the cheap copy of the Buffalo Turbine blower made by Toro http://www.toro.com/grounds/utility/debris/index.html

[masalai]

diverdon, - - It is all in the name of self preservation,
1) - -There are those who delightedly engage in a feeding frenzy of retribution at anyone who dares to "advertise" without paying homage to Jeff the moderator /owner?
2) - - I have had a couple of threads pulled because the "self-righteous" got upset at allowing "free speech" as in expression of a point of view, and many enjoyed (by virtue of the rapidly growing number of "views") - namely "drivel" and "Global economics and politics (witchcraft and lies)"
3) - - Being a long term reader, I would have presumed that these aspects of "internal politics" would not have been unfamiliar...
4) - - As an active and interested member with diverse interests (I am building), feel encumbered to assist Jeff occasionally....

My apologies if you felt put-out - that was not my intention - but to discourage the prospect of a flame war on an interesting thread ...

My best wishes to you all...

[eponodyne]

Masalai,

Thanks for posting that. It always helps to clear the air a little.

I think that it might help, when talking about kite-assist technologies, to define what size and class of vessels we're discussing. What a VLCC or Panamax freighter needs is a lot different to what a dinghy sailor could use, and that's different to what a blue-water cruiser might need.

I don't know much about the Skysails developments-- not many here besides Dave Culp do, I'd wager; but I have been flying controllable kites for years, kiteboard frequently, and have a pretty good grasp on what's involved with the consumer-level kites on the market these days.

First, the idea that they're "uncontrollable:" the whole point of control lines is to control the kite, and they do this with aplomb and efficiency. Even a behemoth like the Flysurf 19 sq m is easily made to do what you want it to, for a very simple reason: You don't steer the kite by sheeting in against the pull, you steer it by dumping lift off the side toward which you want the kite to go. Easing lines, not sheeting in. It doesn't take much, either-- a nudge of that side of the bar toward the kite, wait a second or two, then another nudge on the other side of the bar.

Second, that they must be kept flying by waving them all over half creation: Well, kind of. These kites were designed to pull surfers around over waves, and as such, some of them aren't terribly stable. So, yes, those kites need to be constantly tended. But more and more kites are being made so they're stable in flight--Peter Lynn's Scorpion series actually will auto-zenith, which is to say they will return to a stable overhead position absent any other input. Many other kites, especially the flatter-cut "Bow" kites, will happily hold a "park and ride" postion, where you hang the kite somewhere and it just... stays there. Airflow and lift and drag and everything balance out. On a board, this requires very minimal attention, probably because of the scant mass of the vessel. On a larger boat, it would be interesting to see if this workload would be reduced, and I think it would. Anyway, for a daysailor, isn't half the fun pulling on the bits of string?

Third, the idea that kites can't work upwind. Well, if that's true, then planes can't climb to altitude. These aren't simple bags to capture the wind we're talking about here-- these are complicated wing assemblies that happen to be made out of cloth. The leading edges are often inflated (which provides support and shape) making them water-relaunchable in the process. Now, I think the jury's still out on just how far upwind a kite can work, but I know for a stone fact I and my kiteboard rig can point higher and work upwind faster than the ubiquitous Hobie 16. I know this because I won $50 in a bet last summer doing just that.

Fourth, the expense. These kites don't cost any more than a comparable sail of similar quality; figure about $1-1.5K USD for a decently sized (10-12 sq. m)kite from a reputable manufacturer. Usually comes complete with Spectra or Dyneema lines and a control bar.


I think kites are the future, I've said so before on this forum and even upthread in this very discussion, at least for daysailors. No masts, no chainplates, no shrouds, no backstays, no vangs, booms, spars of any kind. Four or five lines, and no need for Harken blocks anywhere. No halyards tapping the mast at anchor. No overengineering the hull to support the loads delivered by a tradtional sail and mast. No ballast needed to keep the boat on her feet. Easy to use. Safe for children.

[masalai]

eponodyne, Watching board-sailors have fun is small choppy inshore shallows, is what got my original interest in thinking of same for cruising cat... You will notice that most cruisers drink coffee or other stuff during the leg - - autopilot steers, and the sails are set - - so unless there is a reason to change course because of wind or another boat etc, enjoying the sail...

Those folk on sail-boards seem to not only be working the sail but their arms are automatic shock-absorbers between a "steady force" of the sail and the pumping of the "boat" over the waves - I do mot propose to shackle a "deck-ape" to the hitching point to perform the shock-absorber function... :D:D

On some legs kites/parachutes perform adequately, and it will take a lot of beating to replace my "hitch-hiker" rig - which is basically a pair of large genoas on furler/reefing lines to each bow from the normally positioned (maybe slightly cantered aft) mast and a forward cockpit for sail-handling. This leaves my bridgedeck roof free for placement of solar PV panels - another cruising need for live-aboard comfort and independence...

[apex1]

I don't know much about the Skysails developments-- not many here besides Dave Culp do, I'd wager; but I have been flying controllable kites for years, kiteboard frequently, and have a pretty good grasp on what's involved with the consumer-level kites on the market these days.


There are some more that know this development pretty good. look here:

http://www.boatdesign.net/forums/boat-design/get-home-kite-sail-27091.html

almost everything is said there. Focussed more on coastal and blue water sailing though.

It would be interesting to know how one would be steering the boat (not a nutshell) and contolling the kite. As a proper propulsion for average joe on a "real" boat you cannot substitute the electronic control like Skysails.

Period

[brian eiland]

Video (http://www.youtube.com/watch?v=tSWfi5AMT2E&feature=related) showing stability of a Peter Lynn kite.

This is promising, my experience with traction kites is that they have to--have to-- be flown all the time. Apparently the model shown is water-relaunchable as well.

Hmmmmm.
Peter Lynn

http://www.youtube.com/watch?v=tSWfi5AMT2E

http://www.youtube.com/watch?v=dh8GIZ7SmAc

http://www.youtube.com/watch?v=Fe_kP-nEgYs&NR=1

http://www.youtube.com/watch?v=Bw3Di0v96YE

[brian eiland]

http://www.peterlynnkites.com/vehicles/vehicles.htm

[Guillermo]

Brian,
those Peter Lynn's kites seem to be pretty stable, but would you rely on them as to fly them at night when cruising?

Cheers.

[brian eiland]

Brian,
those Peter Lynn's kites seem to be pretty stable, but would you rely on them as to fly them at night when cruising?
I don't truly know at this stage, Guillermo, but I did find this quote interesting.

...
First, the idea that they're "uncontrollable:" the whole point of control lines is to control the kite, and they do this with aplomb and efficiency. Even a behemoth like the Flysurf 19 sq m is easily made to do what you want it to, for a very simple reason: You don't steer the kite by sheeting in against the pull, you steer it by dumping lift off the side toward which you want the kite to go. Easing lines, not sheeting in. It doesn't take much, either-- a nudge of that side of the bar toward the kite, wait a second or two, then another nudge on the other side of the bar.


Fourth, the expense. These kites don't cost any more than a comparable sail of similar quality; figure about $1-1.5K USD for a decently sized (10-12 sq. m)kite from a reputable manufacturer. Usually comes complete with Spectra or Dyneema lines and a control bar.


I think kites are the future, I've said so before on this forum and even upthread in this very discussion, at least for daysailors. No masts, no chainplates, no shrouds, no backstays, no vangs, booms, spars of any kind. Four or five lines, and no need for Harken blocks anywhere. No halyards tapping the mast at anchor. No overengineering the hull to support the loads delivered by a tradtional sail and mast. No ballast needed to keep the boat on her feet. Easy to use. Safe for children.
So it doesn't sound as though it would be that much more difficult to build the 'electronic control unit' for the "easing lines" than to build a good electronic autopilot??

[Tad]

it doesn't sound as though it would be that much more difficult to build the 'electronic control unit' for the "easing lines" than to build a good electronic autopilot??

The brains are cheap and easy.....it's mechanical parts that get difficult. Which is why this is not common.

I believe the kite has 4-5 control lines. In a big heavy cruising boat these lines are under high load at times. These lines must be long, and quickly and infinitely adjustable. This means a bunch of captive reel winches (heavy, complex, expensive) run by a computer. Fine for the engineers in the crowd. The typical cruiser is crewed by a relatively feeble retired couple, not a young athletic crew out for a daysail.

[brian eiland]

But Tad I believe this is a major difference with the 'older' idea of flying the kites...multiple lines to the vessel. The Skysail system sheets its line to the control pod that is tethered to the vessel by a SINGLE line. The control pod handles the flying of the kite without resorting to, " a bunch of captive reel winches (heavy, complex, expensive) run by a computer".

You don't steer the kite by sheeting in against the pull, you steer it by dumping lift off the side toward which you want the kite to go. Easing lines, not sheeting in

[Tad]

So........

The Sky Sails system consists of...at least...

A "Kite", which they say is cheap.

A "Control Pod", unique in the world....not cheap, not fixable by joe the plumber.

A "towing rope", specially braided with control and power cables included...definitely not cheap.

A "Force transmission point", again unique in the world, hydraulic or electric powered.

A "winch", unique to the application, custom unit.

A "control unit", (computer) semi-custom software is not cheap in my experience.

A "launch and recovery system", again custom hydraulics with electronic controls.

All of the above is somehow cheaper and easy to repair and maintain than a mast and a sail?

[brian eiland]

Didn't say it was going to be cheap, but might offer unlimited range without being a 'sailboat'.

And from my very first posting on this subject thread:
Only two engines and no conventional sailing rig should make this a more affordable vessel, both in construction, in maintenance, and in operation. However the SkySail kite arrangement will probably more than offset the conventional sailing rig in cost. Possibly a less expensive alternative to this ‘brand name’, with less computerization could be found (no integrated weather/navigation features, etc)

Might be rather exciting to own the first one as well :cool:

[apex1]

Might be rather exciting to own the first one as well :cool:

That´s too late, there is at least one yacht under construction at present with a "Skysail" system.

TAD, I completely agree with your comments above. But we have just to be more patient to see affordable and comparable prices. "Skysail" started production of the first sets just hours ago.

Regards
Richard

[eponodyne]

I don't truly know at this stage, Guillermo, but I did find this quote interesting.


So it doesn't sound as though it would be that much more difficult to build the 'electronic control unit' for the "easing lines" than to build a good electronic autopilot??
I've actually been thinking a gyroscope control might be the way to go. The technology is certainly available and proven. Would probably not be too badly affected by the shock loads encountered on a boat (rarely over 1G, as opposed to what they endure in aircraft). So an electro-mechanical device, with bellcranks and pushrods. Might as well do it in bronze, with black enamel filigree work. Some crazy sort of Difference Engine providing negative feedback. It would probably work well enough in steady winds to keep the kite more or less where you want it.

There really isn't much shock absorption going on with the kite and the lines, again probably due to the low mass of the vessel (More, in my case. I daresn't wear my regular wetsuit due to an overweening love of Carbohydrate Surprise With Extra Butter) allowing a bit of leeway to happen as the kite takes a greater load. Remember, though, that the kite is in point of fact tied to the rider through a seat/belt harness, to transfer load through the rider's CG. The same arrangement would be enough to get a boat going, though I suppose a cautious man could make up a lizard out of like 12mm nylon 3-strand to act as a snubber of sorts.

By the bye, I had what happens with the kite, to turn it, crossed up. Shove left to turn right; shove right to turn left.

[Fanie]

I flew my friends sports kite before. One thing I was interested in was if it can fly to wind like a sail. It can and pretty well too.

I was under the impression it had four lines, and I asked him a couple of nights ago, but he says no, it only has two lines, similar to the Peter Lynn's
kites. If your arms get tired you can park and hold the kite right above your head, then drop it when you got your breath back. Good exersize when the wind is really up ;)

As for shock absobsion, would one really need it ? Sails have no shock absorbsion other than accellerating the boat or heeling, and also it seems in a gust the kite tends to fold up some, kind of like tending to bringing it's arms closer together.

Electronic controlls is not going to be that difficult, although probably not as cheap as someone commented, but that depends how a reliable system you build. If the control module is allowed to hinge on deck you can get a direction feedback wrt the angle the kite is wrt the boat. The lines angles wrt to the horizontal is another indication of where the kite is. So even if at night and you cannot see the kite at all, all the indications can be made visible with electronics.

The automated control for flying a kite can be made easily if you use the electronic feedbacks for control and use some engineering things commonly in use on machinery, a motor driving a rack and pinnion or a nut and acme thread are both mechanical forces for control. Mechanical arms etc can still be good old stainless steel.

Getting the kite up also doesn't have to be that difficult. If you drive into the wind using the iron sails you probably won't need much speed to get it up. It does however require a bit of fuel.

The only unknown is when the wind dies down or when you encounter a change in wind direction. A radical change in wind would bugger the kite up for sure, which may require retreival and untangling. Would probably happen at night and under the worst of conditions too :D

[brian eiland]

That´s too late, there is at least one yacht under construction at present with a "Skysail" system.
Which one is that?

[brian eiland]

..Second, that they must be kept flying by waving them all over half creation: Well, kind of.
I think there is some misunderstanding here. One of the reasons the kites are 'flown' in an exaggerated manner is too be able to extract more pulling energy from them per square foot area...more power from a smaller kite.

Remember the old theorem, the pressure goes up as the square of the velocity of the wind. So if you fly figure-eights the kites can develop substantially more power/sq ft.

[apex1]

Which one is that?

I was shure that question would come.
Sorry. agreement of non disclosure.

Regards
Richard

[rob denney]

G'day,

When we flew the 420 sqm Outleader in little or no air, we found that a helicopter hovering off the back of the boat was enough to get the kite up, but not keep it up. As soon as the boat started to move, apparent wind came forward and it collapsed. With a little more crew ability, it would be posible to sail on a reach so that the apparent was helping, not hindering. So, a blower could be a handy gadget in marginal conditions, although the work required to keep the kite flying in these conditions would probably not be worth the effort for cruisers.

The figure 8 stuff is not necessary on cruisers, nor when going to windward. In fact, the figure 8 is one of the big things holding back big boat use. Power increases by the square of the windspeed, so if the kite is flown across the sky, it can quadruple it's apparent wind, with enough power increase to rip winches from the deck.

Outleaders are self stabilising, if set up properly. To trim them, you ease the corner that is heading for the briny. If the lines are far enough apart, as the kite dives, the sheet on the diving corner gets longer, the kite stabilises. Works well on cats with the wing lines on the gunwhales amidships and the tail line on the fore beam.

They cannot be parked, and are a big nuisance if they fall in the water. However, this should (note the should;-)) only occur in lightish winds as in a good breeze, the collapsed kite streams downwind.

Kites are the rigs of the future, but there is a way to go before they replace sticks and sails. Fortunately, there are a lot of very clever people working on them, so it is only a matter of time, and overcoming boat owners' conservatism.
regards,

Rob

[Guillermo]

I was shure that question would come.
Sorry. agreement of non disclosure.

Regards
Richard
There was that Humphrey's designed trimaran, wasn't it?

[apex1]

There was that Humphrey's designed trimaran, wasn't it?

You said that Guillermo. Not me

[Boston]

I've actually been thinking a gyroscope control might be the way to go. The technology is certainly available and proven. Would probably not be too badly affected by the shock loads encountered on a boat (rarely over 1G, as opposed to what they endure in aircraft). So an electro-mechanical device, with bellcranks and pushrods. Might as well do it in bronze, with black enamel filigree work. Some crazy sort of Difference Engine providing negative feedback. It would probably work well enough in steady winds to keep the kite more or less where you want it.

There really isn't much shock absorption going on with the kite and the lines, again probably due to the low mass of the vessel (More, in my case. I daresn't wear my regular wetsuit due to an overweening love of Carbohydrate Surprise With Extra Butter) allowing a bit of leeway to happen as the kite takes a greater load. Remember, though, that the kite is in point of fact tied to the rider through a seat/belt harness, to transfer load through the rider's CG. The same arrangement would be enough to get a boat going, though I suppose a cautious man could make up a lizard out of like 12mm nylon 3-strand to act as a snubber of sorts.

By the bye, I had what happens with the kite, to turn it, crossed up. Shove left to turn right; shove right to turn left.

how about a pendulum system to alter the center of gravity and turn the kite back and forth
could be a simple wound spring unit with watch gears and a wireless servo to adjust the swing of the pendulum and so the size of the figure eight
one simple radio control unit and a power winch
regular old line

launching and recovering it would be the fun part
but once its in the air in a steady breeze

skimmed this thread
what a great idea

[masalai]

That is how I understand the "commercial" control system works with an electronic control winding up on one side and out on the other to direct the kite in a manner to maximise the towing effort with just one main "springy" line to absorb the rise and fall of the bow so the kite does not deflate... a fairly simple exercise basically moving the control ballast across the junction or the individual control lines to the "pendulum", to which is attached the prime tow rope...

[brian eiland]

Which is first yacht application?

I was sure that question would come up.
Sorry. agreement of non disclosure.

Couple of more possibilities for first yacht application??
1) Design Valbella:
The French dock yard, 30 Metres Plus Yachts, has signed the first sales contract for a SkySails super yacht system. 30 Metres Plus Yachts will install the SkySails-System on the new built Valbella, a 40 metres SkySails motor hybrid super yacht. The Valbella will be able to soundlessly cross the sea using the SkySails-System without support from the main engine. The dock yard in France plans to specialise in the construction of SkySails motor hybrid yachts after completing and testing the Valbella.
30 Metres Plus Yachts (http://www.30m-yachts.com/trente-metres-plus-yachts-en.php)

2) Design VPLP:
At the 2007 Festival de Plaisance in Cannes, Van Peteghem Lauriot Prévost Yacht Design were publicising the Noah 76’, a semi-production power catamaran designed to carry an optional 80m² SkySails that could drive the yacht at around 10 knots. Designed as an auxiliary system, the canting launch mast would be mounted on the beams connecting the two hulls and supporting the forward trampoline net.

3) Design Humphreys: (note:MY FAVORITE)
This 40m Motoryacht represents a new development in yachting, merging the benefits of a low resistance, fuel-efficient hull form with an unusual propulsive device - a fully automated, self-tending kite.
PFD Concept (http://www.skysails.info/fileadmin/user_upload/documents/Dokumente/Hintergrundinformationen/EN/EN_Humphreys_Brochure.pdf)

Guess which one won the first contract??

[brian eiland]

I think there is some misunderstanding here. One of the reasons the kites are 'flown' in an exaggerated manner is too be able to extract more pulling energy from them per square foot area...more power from a smaller kite.

Remember the old theorem, the pressure goes up as the square of the velocity of the wind. So if you fly figure-eights the kites can develop substantially more power/sq ft.
From their website;

"By means of dynamic flight maneuvers , e.g. the figure of "8", SkySails easily generate five times more power per square meter sail area than conventional sails."

"Their double-wall profile gives the SkySails towing kites aerodynamic properties similar to the wing of an aircraft. Thus, the SkySails-System can operate not just downwind, but at courses of up to 50° to the wind as well.

"Unlike conventional wind propulsions the SkySails-System causes minimal heel."

[Boston]

looks like it would generate a fair amount of lift as well

hey Mas
nice to know I nailed it
thanks
B

yellow kite would be my guess

[masalai]

:D:D:D No no Boston, "screw it then glue it then remove the screws" - ask Fanie:D:D - Oh the other thing OK:D:D:D

[apex1]

Couple of more possibilities for first yacht application??
1) Design Valbella:
The French dock yard, 30 Metres Plus Yachts, has signed the first sales contract for a SkySails super yacht system. 30 Metres Plus Yachts will install the SkySails-System on the new built Valbella, a 40 metres SkySails motor hybrid super yacht. The Valbella will be able to soundlessly cross the sea using the SkySails-System without support from the main engine. The dock yard in France plans to specialise in the construction of SkySails motor hybrid yachts after completing and testing the Valbella.
30 Metres Plus Yachts (http://www.30m-yachts.com/trente-metres-plus-yachts-en.php)

2) Design VPLP:
At the 2007 Festival de Plaisance in Cannes, Van Peteghem Lauriot Prévost Yacht Design were publicising the Noah 76’, a semi-production power catamaran designed to carry an optional 80m² SkySails that could drive the yacht at around 10 knots. Designed as an auxiliary system, the canting launch mast would be mounted on the beams connecting the two hulls and supporting the forward trampoline net.

3) Design Humphreys: (note:MY FAVORITE)
This 40m Motoryacht represents a new development in yachting, merging the benefits of a low resistance, fuel-efficient hull form with an unusual propulsive device - a fully automated, self-tending kite.
PFD Concept (http://www.skysails.info/fileadmin/user_upload/documents/Dokumente/Hintergrundinformationen/EN/EN_Humphreys_Brochure.pdf)

Guess which one won the first contract??

I
do
not know
!?

How could I?

NON disclosure is a very, very, very safe contract in our business.;)

But I must say you have been very keen on that issue!?
Regards
Richard

[Boston]

I know the feeling on that disclosure thing
I have a design on my Elco Ild love to discuss but the engineer asked me not to post or reproduce the work in any way
I can only honor the request even though I would love to hear other opinions concerning the design

my thinkin is its intellectual property and as such protected
but he's feeling kinda shy about it so its exactly as you say
a contract
were I sorta work is the same way as much of what they do must remain completely confidential

[brian eiland]

Yves Parlier's latest innovation: traction by 100% natural energy.

Innovation with nature-sensitive solutions. These are the priorities which Yves Parlier wants to share. He is now developing traction by 100% natural energy, and uniting wind and solar power in three cutting-edge technologies.

http://www.parlier.org/beyond_the_sea/eng/beyond_the_sea.php?beyond=1

[brian eiland]

I do not know!?

How could I?

NON disclosure is a very, very, very safe contract in our business.;)

But I must say you have been very keen on that issue!?
Regards
Richard

Who won first contract....Design Valbella, the first one above. The information came from SkySails website

[Guillermo]

I think Parlier has yet a long way to go....

Cheers.

[Boston]

G filled out a few papers for that grant today
cant believe how fast things are progressing
thanks for all the encouragement
B

[brian eiland]

I think Parlier has yet a long way to go....Cheers.
But watch out, it's amazing how those French are able to corral money for 'sailing' projects

[apex1]

Who won first contract....Design Valbella, the first one above. The information came from SkySails website

Skysails does´nt say a single word about the first yacht under construction.

[brian eiland]

Speaking of 'control' over those kites, have a look at the women in kite sailing...inspirational. Enjoy the video and sights

http://www.youtube.com/watch?v=LtY4bcI_fM0



(this was brought to my attention by forum member Fanie...thanks :D )

[Fanie]

You have to admit, you can't beat the inspiration ;)

[mydauphin]

Kite flying is very dangerous, It could kill me just watching

[M-Sasha]

Speaking of 'control' over those kites, have a look at the women in kite sailing...inspirational. Enjoy the video and sights
(this was brought to my attention by forum member Fanie...thanks :D )

And when do we stop to mix "cotrollable" and "controllable on a seagoing boat without the hassle of personal involvement in every single moment" ?????

All the statements and contributions above have had a very enjoyable part:

not sufficient for "bluewater sailing" what so ever that means.

Controllable means fit and forget, like a classical rig! If its more than that, in terms of personal involvement, it is crap.

Richard made that very clear in several of his (usually unpolite) statements.

Sasha

[brian eiland]

..Controllable means fit and forget, like a classical rig! If its more than that, in terms of personal involvement, it is crap.
Sasha
So I guess you greeted those 'new multihull vessels' that appeared on the scene a number of years ago with that same open mindness and future vision. :rolleyes:

[apex1]

So I guess you greeted those 'new multihull vessels' that appeared on the scene a number of years ago with that same open mindness and future vision. :rolleyes:

That was at least off topic, if not to say unpolite! Open mind and knowledge go very often hand in hand.

And the statement was absolutely valid, what do you believe is "controllable" at the open seas? Your dreams? A kite that is held in your hands? How long is a watch? And how long is a watchkeeper able to control a boats propulsion?
You should be a bit more serious if it comes to new tech! Not everyone (btw) is a absolute novice in multihulls. Alexander (Sasha) was one of the most experienced multi sailors in the former USSR.

Your "future vision" Brian is quite often just a copy and paste vision, sorry! >>>>not very sorry<<<<

Kindest
regards
Richard

[brian eiland]

Richard, I've been involved with multihull development almost since its inception. And I heard that word 'crap' thrown around many times when the author was least informed about a subject matter. So when someone throws that word out now I get a little defensive.

If you bother to go and read the links I offer about the SkySail technology, you would realize that I have much more respect for this technology to actually become reality on open ocean vessels.

The numerous links to recreational kite sailing are hipe. But on the other hand they are developmental platforms that spur futher development. They demonstrate the power in kites, and the potential for controlling it.

Speaking of control, we've developed an auto-pilot that is able to allow this one man to control a 60 footer in some rather heavy weather.
http://www.youtube.com/watch?v=CIuGoT7WoKc
Surely we will gain control of these kites to propel our ships

[apex1]

Surely we will gain control of these kites to propel our ships

I agree Brian, we will!
Skysails has already.

[eponodyne]

I think there's a disconnect here, in that some of us are talking about using kites as propulsion-assist on VLCCs or trawlers and some are wondering how a kite could possibly be useful for bluewater passagemaking, and some chit-chat about using kiteboard rigs for daysailers. It seems to me that the answer is simple: Different rigs for different applications.

In the last days of working sail--let's say 1850 to WWI-- the variety of rigs carried by different vessels was simply staggering. This was not, however, some chaotic gallimaufry of canvas and spars: The needs of a couta boat were different to what was needed on the Thames was different to what was needed on the Shanghai tea run. Rigs evolved to be a good fit for their prevailing conditions: There's a reason you don't see barquentines in the America's cup, and why the Flying Cloud didn't have a single small standing lug.

There is no one single right answer. I am confident, however, that since there's a mint of money to be made by bringing kites to market, the private sector will move quickly to fill the needs. I don't believe we would be having this discussion in 10 years' time, much less 20.

[sigurd]

diverdon: "From my child hood kite flying it always seemed that the hard thing to do was to get the kite properly launched through the still or gusty air near the surface. I have to imaging that even with these kits launching them can be a problem. There must be many occasions where the air aloft would be suitable for use but the kite is not used because the launch or recovery conditions are difficult."

sigurd: If there is little wind, the engine can assist the launch by propelling against the wind.

masalai: "For recreational sailing craft - a fun toy but difficult to control on cruising yachts as the "para-sail" is usually flown in a figure 8 pattern to maximise performance, particularly more-so if seeking a bit more upwind benefit..."

Sigurd: Flying dynamically robs the system L/D. So for pointing, no. In light wind, maybe.

Tad: "I believe the kite has 4-5 control lines. In a big heavy cruising boat these lines are under high load at times. These lines must be long, and quickly and infinitely adjustable. This means a bunch of captive reel winches (heavy, complex, expensive) run by a computer."

Sigurd: Two lines for control, one or two for power. All four can go on the same reel, then you need two mechanical actuators in addition to the reel. Range for these (linear?) actuators are about half a meter (on kitesurf size kites) unless block purchase is used.

Fanie: "I was under the impression it had four lines, and I asked him a couple of nights ago, but he says no, it only has two lines, similar to the Peter Lynn's
kites."

Sigurd: PL traction kites have four lines.

Fanie: "The only unknown is when the wind dies down or when you encounter a change in wind direction. A radical change in wind would bugger the kite up for sure, which may require retreival and untangling. Would probably happen at night and under the worst of conditions too "

Sigurd: Yes, absolutely, this is the shite. Whether the kite is likely to tangle when dropped is depending on the model of kite.
Pulling in the lines in such lulls would be helpful.

[sigurd]

Just came down from the snow dunes of Hardangervidda playing with my new Flysurfer Speed 2 10m and a little review:

My former kites were all Peter Lynn Phantoms, these are ARC ram air closed cell kites. Only four lines all the way to the kite, like many inflated kites (tube kites), unlike the FS which have an intricate bridle like a paraglider. The phantoms are out of prod. but were the most efficient PL's mass produced AFAIK, due to the high aspect ratio. Due to the lack of bridle, tangles are nothing compared to the FS, when it happens.

Both are water relauncheable, so suitable for boats. The FS has a lot higher CL, means much more power per area. In the snow it is useable from almost walking pace wind. Phantoms require more.
Have not met FS top end yet, but the depower is quite astounding. It comes in a lighter fabric as well as the standard, making it even better for light winds.

Much more powerful than phantom 12 and steers quicker. Much more direct throttle - a two edged sword, since the mushyness of the Ph. is part of what makes it so great in gusts - it eats them and gives the rider a safer feeling. FS is more prone to luffing/overflying and collapsing at the edge of the wind window, in slight wind changes. It requires much more attention than the Ph. The Ph, as will most the arcs, will fly to zenith if you let go the control bar - nice feature for chatting or smoking, cutting hole in the ice for a drink etc.

The safety release to one line of the Ph is very safe and nice, it will go to ground like a flag and pull very little.

On four lines the safety release and landing system of the FS is inadequate, IMO. It will flog around like a bat (out of hell) on a string and make a terrible mess, if there is much wind. The pull can meanwhile be on the border of too much for retrieving the kite unless you have an achor point for it and can walk down to the kite. There is a fifth line system for this kite that I want to try, said to make a better release system.

Both has one way valves in the leading edge to make them suitable for water.
The FS has overpressure valves to protect it when crashing. I have blown a cell in the phantom 6 when crashing, earlier.
Both seem rugged and well built, ARCs have short sticks at the tips.

To extrapolate this to kite sailing, I believe these are both superb for that. The phantoms are much easier to fly, but will require acres of kite for a big boat. Probably the newer, lower aspect PL synergy is even easier to fly, has more power to to the area, more guaranteed water relaunch and may have a similar depower. As I see it upwind power is a major issue for kite boats - the phantom 12 is like nothing compared to an 8sqm una-rig - upwind.

Side note, the jumps with the speed2 is just frackin amaiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiizing.

[Hacklebellyfin]

In 1995, Nicole Van de Kerchove crosses the South Atlantic in solo on board a hull of sailing ship tractor-drawn by Kite(s)
functioning only in the axis of the wind. A system which makes it possible to sail in the trade winds, but only in rear.

[eponodyne]

The way she did it certainly worked for her. In my eye, though, her boat looks more like an escape pod than a sailboat, though. It's way too heavy and the pull of the kite is coming from too far above the waterline to take advantage of leeward pull to eliminate heeling.

Still, the fact remains--she did it, and has a lot more to say on the subject of deepwater cruising with kitesail than I am likely to ever learn.

[Hacklebellyfin]

The boat wasn't a pod it was a unmasted sailboat a jod24.
Unfortunately we could not hear from her anymore because she died the 21 st of February 2008 in Patagonia on the island of Navarino.

Rest in Peace Kitesailingwomen.

[dump-box]

first, bow kites, "c" kites are practically self launching and unlike my sails, don't becomed waterlogged. As for skysail's tech, ok what exactly does the computer actually do/ pull lines in or out to turn the kite (btw power kites like skysail are a b!tch to control by comparison to a bow kite). thats all it takes to control a kite, in and out - not around like a wheel. Your telling me that i couldn't use a simple mechanical wheel and drum /spindle to control the in and out action on a kite with a simple wheel. Seems like thats how squares controled the rudder/tiller 300 yrs ago. Tending to a kite during launch is the hard part. Once launched, a bow kite can be "parked" into the wind, where it needs slight finger tension to control (see playing the paino technique). Tending to a kite seems just like tending to my jib to me. As for rudder, simple, just like a plane, rudder pedals. To launch a kite, on a boat, use the motor. And to control the power on a bow kite, the "5th" line is used to change the angle of attack to power or de-power the kite. You don't need to tend to a kite every second. We didn't need a computer to control a nike/ajax missle into another missle, it was electro-mechanical and analog. Heres a real sificated ide-r, how bout pots to control the linear actuators needed to keep a kite in power.....seems pretty simple to me. I've been running some simulators with a kiteboat at home, and I can say that you definately need keels to keep it on track when tracking upwind, and i found that attaching the kite just slightly aft of the cg seems to work better then on the bow in tractor mode.

[apex1]

And on a long passage you do that controlling by fingertips, yes? Like playing a piano?
Thats a idea out of the dump-box, for sure.

[eponodyne]

first, bow kites, "c" kites are practically self launching and unlike my sail [snip, good post]found that attaching the kite just slightly aft of the cg seems to work better then on the bow in tractor mode.Care to post yer thoughts here? (http://www.boatdesign.net/forums/boat-design/kite-power-daysailing-cruising-thread-28085.html) Do you have pictures of your models?

[brian eiland]

Interesting posting this morning on what might be termed an economy model cruising tri-hull configuration powered craft with an aux lateen sail in place of a kite.

http://www.yachtforums.com/forums/84017-post66.html

..similar theme :?:

...but this one can be shipped to its cruising ground rather than getting there on its own bottom.

[Guillermo]

Interesting boat, Brian, thanks
Do you mind if I cross-post also this info at the 'containerable motorsailers (http://www.boatdesign.net/forums/motorsailers/containerable-motorsailers-11797.html)' thread, just to gather there all possible information about such boats?

Cheers.

[Tad]

That boat has already been posted on the Containerable Motorsailors thread, more info on the build and design here.....

http://www.cruisersforum.com/forums/f48/beau-boat-9093.html

Not a huge success

[brian eiland]

Interesting boat, Brian, thanks
Do you mind if I cross-post also this info at the 'containerable motorsailers (http://www.boatdesign.net/forums/motorsailers/containerable-motorsailers-11797.html)' thread, just to gather there all possible information about such boats?

Cheers.
Not at all Guillermo, I assume you mean to link it on this forum.

I have a problem with that Cruisers forum...just too much moderation...almost a 'if it didn't originate there, it wasn't allowed' atmosphere. I had several of my postings removed from that forum by the moderators, and when I posted a complaint under AN EXISTING subject thread on the matter I was told this was not allowed... making a negative comment about too much 'moderation'. It appears as though one is not allowed to post any negative feedback...real freedom of speech over there.

[will101]

Howdy I'm a bit behind in this discussion but it I find it very interesting. I'm essentially a powerboater and locally our fishing grounds for tunny is a 30 to 40 nautical mile trip offshore. In the summer months when fishing is good, the return trip is pretty much downwind. I have a 22ft sportfisher which weighs between 1 and 1.5tons depending on load.
I have often toyed with returning to base in a kite-assisted manner, even if only at about 5knots. Is there anyone that might be thinking along the same lines?
Obviously the main drawcard would be fuel savings, with a fishing outing for the day often costing between $300 and $600 in fuel.

[brian eiland]

....I have often toyed with returning to base in a kite-assisted manner, even if only at about 5knots. Is there anyone that might be thinking along the same lines?
Obviously the main drawcard would be fuel savings, with a fishing outing for the day often costing between $300 and $600 in fuel.
I think there are folks thinking about this, but many have probably relaxed again with the drop in Crude prices...but don't get too relaxed, those prices will be back soon with a vengeance.

And likely there are very few of those fishing guys reading this sort of subject thread.

[brian eiland]

In a recent discussion on Passagemaking Under Power, the subject of "Get Home Power" came up

.... I too have conventional sails as a "get someplace" alternative. Is that the perfect solution? Not by a longshot.

Right now, I am exploring the possibility of a para-wing kite as a more controllable system. My neighbor is an avid kite boarder and I am learning the nuances of kiting.

The response was interesting:

We had looked at using a traction kite several years back on Swan Song (http://www.missnancysjournal.moonfruit.com/#/mv-swan-song/4512603592). I had several emails, calls and proposals from a couple of companies interested in the project but when push came to shove nothing developed that could be purchased then.

There have been many kite advances in the past few years and I think that a kite is a very viable aux power system for a passagemaker. Both as a "get home" and fuel saver on long passages. Significant power can be developed with a traction ( as opposed to a sport kite) kite in the off wind passages that most of us favor. I for one really don't like slogging into head seas/winds for days on end even tho our recent Mexico-Hawaii passage had two full days of this. Beam and aft wind/seas are much preferable. Most passagemaking, as opposed to delivery passage planning, should focus on making major runs with the wind/sea aft of beam. This blends into the strength of the kite.

Kites can offer power from 110 degrees off the wind. This translates into a usable arc of ~140 degrees. All but 500 miles of our recent 2700 km passage, for example, would fit in this wind angle.

A kite with a nominal pull of 20-25 HP would have given us a ~ 4 kt speed under kite alone or decreased our fuel consumption by about half. So we'd have a "range extender" and Swan Song would have an 8000 km range vs. the 4000 miles we have based on the MX-HI trip. A significant advantage, IMHO.

How big a kite to do generate this pull? That is very dependant on the design. Spinnaker type kites are large but inexpensive and have several disadvantages mostly becoming a drogue :-( Rigid wing kites are much easier to fly, can be water launched and recovered from the water easily. They are controlled from a single control point with two or three lines. There are designs range from self inflating (not good for us). to ones with battens to those that are inflated with pressure for shape (best for us, I think). All of the rigid wings develop more power than the early spinnaker designs for a given size. Size and design is important in launching from a deck as we don't want to intentionally launch from the water nor have an unruly web of fabric/lines looking for a place to self destruct.

Launching from a foredeck pylon, aka a small mast, could be easy and once launched the kite flies from just above deck level to what ever altitude you desire. The higher it is the more wind there is thereby the more available power. Parked over head they develop no power. As you pull the control lines they move forward of the boat and generate incredible power. Easing the trim and they depower instantly. Using the trim to move them from side to side increase the average power even more.

Sitting a kite surfer of the foredeck in a chair strapped down to the deck with a seatbelt should be a good seat of the pants test as how one of these work and could be adapted to a passagemaker.

This certainly would be far cheaper than a wing engine, I couldn't see more than $15K for the whole system, and it would not have the issues of space and additional fuel consumption of twins.

I suspect we'll see someone doing this in the not to distant future...perhaps Patrick and his avid kite boarder friend can try it out and send us a picture with some data. Pulling around a Willard 40 in La Paz would be in the least a good tourist attraction and perhaps even a fun YouTube video ;-)

[will101]

I intend doing the same and will report back for interest sake. I have a 10sqm surfing kite and my thinking is that if that kite can get a 100kg person airborne - with power to spare, it should be good for a pull of about 10 to 15hp. Enough to get up to 5 knots on my boat, which is ideal for trolling lures - something which really chows fuel and is disliked by 2stroke outboards. Hey, every bit helps!

[Fanie]

Hi Will,

Put some pics up will you ? It would be most interesting to see.

[sigurd]

And on a long passage you do that controlling by fingertips, yes? Like playing a piano?
Thats a idea out of the dump-box, for sure.

For this task, computer- or analog-controlled, kite powered pneumatic/ hydraulic muscles are indicated. you know, stuff a bladder into a hollow-braid.
use the force variation of the traction line(s) to pressurize air, to be used for pulling the control lines.

more like playing a bagpipe.

edit. but of course there is accelerometers on the kite/string, or any number of other sensors (from the rc aviation shelves), to feed the valve control cirquit! those things and their energy source weighs but naught!

edit. obviously, the yaw, pitch and roll of the boat can be modulated the same way.

[apex1]

Sigurd we had that debate on several occasions. I know whats possible, and have mentioned it a dozen times now.
All the attempts to manually control a kite on a passagemaking boat are premature dreams, nothing else. These people have never been sailing for longer than a few hours (if that long).

cheers
Richard

[sigurd]

What debate? Which possibilities is it that you mentioned a dozen times, I must have missed it.
I was mentioning how I would go about electronic control of the kite - hands off, cheapish and light.

If I had no knowledge of or access to electronics then surely a purely mechanical system could be devised.

If a weight is added to the corner of a normal kite it can hold its position in the sky if the winds are consistent.

Controlling the kite manually does not have to be very laborious so if anybody wanted they would not need more than 3-4 shifts of one crew each for a reasonable working day.

Ive been sailing a few regattas going over more than 24hr and been working on fishing boats and factories with 24hr+ shifts (overtime ofcourse), and also have kited a fair amount on snow and I have got two small kiteboats.

If you haven't kited, and believe it is too strenous for long passes, check out those who went kiting across greenland s to n IIRC - mad daily averages that could only have been done by many hours of high speed kite-skiing (with sleds) each day. Normal schoolkids, no super egos or olympic aspirations far as I could tell.

Not only would it (passagemaking while manually controlling a kite) be possible, it would not even be unreasonable - if one had the inclination.
I would rather try to make a proper autopilot for it.

[apex1]

There have been many threads and posts in the past few years here mentioning a kite as a alternative "coming home" propulsion, especially on passagemaking motor boats. A very promising and "clean" solution, no doubt. Every single time we had that topic someone came up with the idea of making it as cheap as possible by controlling the kite manually. Not a single one of these people has been a seasoned sailor on long passages!
The typical passagemaking boat is manned by a couple, thats it! Going watch over extended periods is a burden when nothing but steering the vessel, looking out, and controlling the systems is the duty. Handling sails is already a additional effort which usually is avoided until both hands are "on deck" (when we talk sailing boats). The manual controlling of a kite is NOT POSSIBLE on long legs. Fatigue is one of the reasons, and a quite important one. Steering the boat AND the kite with just two hands another.
Skysails has a very good and professionally done system. We just have to wait until the prices come down. Of course if one can make his own "black box" control system that might be a good solution for him.
Not to get me wrong, I´m a advocat of such systems since more than a decade, but I know what one can bear on passages and what is too much of a workload to be sensible.

Regards
Richard

[brian eiland]

I found this interview in a recent issue of Sea Horse Magazine. They are speaking with Gino Morelli of Melvin/Morrelli Design (http://www.morrellimelvin.com/)



SeaHorseMag: You’re given a clean sheet of paper and asked to design your ultimate multihull...

GinoMorrelli: For me right now it would be a powercat! My personal solution is into powerboats due in part to the fact that I have a wife, kids, a business and a schedule. Sailing is now a luxury I can’t really afford. But if I could guarantee I could go 18-20 kts anywhere any time with a sailboat, then I could almost live a life afloat.

The one thing I can see coming is what could be called the SUV of sailing. There are a lot of cool things going on with drives right now. The aim is to retract, remove, or eliminate the drive when we don’t need it. The problem we currently face is that if we put the right engine in to go 20kts, then the hull shape is wrong. That’s led to tough compromises, but if we can make the power plants lighter, and get rid of the drag of propulsion when we’re under sail, then I can see us ending up with a 20kt boat… it will do 20kt under sail, 20kt under power, and it’s going to be fairly user-friendly all the time.

I also like the thought of kite sails I think ultimately that’s a way to be able to get a high-power low-risk sail plan. The trick is going to be making it auto-pilotable. There’s a bunch of guys working on it, in fact we’re scheduled to test one on one of out Leopard 47 production boats that we’ll soon be delivering from the builders in Cape Town to Tortola. The Moorings is auditioning a couple of guys to build a kite to help reduce fuel costs for their deliveries so we have been fooling around with some of those guys, trying to figure out how we can make this happen and stick it on autopilot. The pilot would control the angle of attack and let us fly the kite day and night

Plus you need to have a simple launch and recovery system... There are some bizarre kite guys out there fooling around with some different designs that have promise. It's just a matter of getting some funding for them so they can build prototypes. The shipping industry is actually pushing the limit of kites a little faster than the recreational side, so we may see some of this development come out of the shipping industry because they have a lot of reasons to get some power out of the wind.
________________________________________________________

SeaHorseMag: And what about your pure performance multihulls.

GinoMorrelli: From here on it’s going to be a horses-for-courses thing. If you’re looking at the next generation of multi to break the round-the-world record as opposed to a single-handed transatlantic, then obviously Hydroptère is where you should look. It’s opening up a giant crack and showing us that it you can spend enough money and are diligent enough then you’re on your way. They are going to get that thing to stay together one of these days, and it’s going to break the 24-hour record and the Atlantic record. And there are some dudes telling you that thing could go round the world one of these days — if you have enough time and money to develop it, foils are definitely the way to go.. it’s an instant turbo. We’re still not sure what exactly that boat’s gonna be — a foil-borne biplane cat or tri, or a foil-borne, wingmasted, tilted bi-plane ‘thing’.

I also have these crazy visions of a big foil-borne, kite-driven, ultra-light three person boat. That’s where the programming and the software for the autopilot for the kite come into play. It’s where you set a ginormous kite then tell it never to develop more than 20,000lb lift. You’d probably control it by just making it drive at a different angle of attack. It’s gonna happen

[apex1]

I also like the thought of kite sails I think ultimately that’s a way to be able to get a high-power low-risk sail plan. The trick is going to be making it auto-pilotable. There’s a bunch of guys working on it, in fact we’re scheduled to test one on one of out Leopard 47 production boats that we’ll soon be delivering from the builders in Cape Town to Tortola. The Moorings is auditioning a couple of guys to build a kite to help reduce fuel costs for their deliveries so we have been fooling around with some of those guys, trying to figure out how we can make this happen and stick it on autopilot. The pilot would control the angle of attack and let us fly the kite day and night
Plus you need to have a simple launch and recovery system... There are some bizarre kite guys out there fooling around with some different designs that have promise. It's just a matter of getting some funding for them so they can build prototypes. The shipping industry is actually pushing the limit of kites a little faster than the recreational side, so we may see some of this development come out of the shipping industry because they have a lot of reasons to get some power out of the wind.
________________________________________________________


What a arrogant (or ignorant) chap!
As if Skysails would´nt exist!

[brian eiland]

What a arrogant (or ignorant) chap!
As if Skysails would´nt exist!
Do you have some sort of chip on your shoulder? It's as though any efforts beyond Skysail's are bogus.

I think Gino realizes the shipping industry is persuing the technologies...ie his quote, "The shipping industry is actually pushing the limit of kites a little faster than the recreational side, so we may see some of this development come out of the shipping industry because they have a lot of reasons to get some power out of the wind."

[sigurd]

hi apex, do you know the weight of the flying part of the skysail AP?

[apex1]

hi apex, do you know the weight of the flying part of the skysail AP?

No I do´nt remember! But it must have been far below 20kg in the early stages of development. At one of the first testruns I have seen one man handling it with ease. The present apparatus might be around 5 or 10 kg I guess.

Regards
Richard

[apex1]

Do you have some sort of chip on your shoulder? It's as though any efforts beyond Skysail's are bogus.

Not bogus Brian! Not serious, or not as efficient, thats all.

I think Gino realizes the shipping industry is persuing the technologies...ie his quote, "The shipping industry is actually pushing the limit of kites a little faster than the recreational side, so we may see some of this development come out of the shipping industry because they have a lot of reasons to get some power out of the wind."

Does that mean he is aware of several commercial run applications? No, that means there MAY be something in the future. Typical US arrogance!

[sigurd]

:o
5kg, that is similar to the weight of a 30sqm (ultralight) kite...

I guess the smallest kites for it must be huge?

God bless old Peacock.

[apex1]

:o
5kg, that is similar to the weight of a 30sqm (ultralight) kite...

I guess the smallest kites for it must be huge?

God bless old Peacock.


That was the first fullsize kite, about 160m² with a lifting/pulling force of about 3 tonnes. Recent studies have shown that the pulling force is much higher than calculated. The recent kite that size pulls 4 -5 tonnes. Do´nt have the data at hand. So whats 5kg?

I assume you did ask for the control unit? Not for the whole kite???

[sigurd]

5kg? Not sure you'd notice it. But, you would, because the kite would crash! (yea thats what I asked for)

[apex1]

5kg? Not sure you'd notice it. But, you would, because the kite would crash! (yea thats what I asked for)

Sorry do´nt understand that.
What was your question, the control box or the whole flying stuff? Including rope and wire?
The blackbox is about 5kg as mentioned. The 160m² kite has a volume of about 2m³ and was handled by a crane (incl. the storage box though)! The whole shebang with hydr. mast, cable and rope drum, storage box etc. will have more than 1500kg, maybe 2 tonnes is my estimation from what I´ve seen.
The actual kite of that size pulls 8 tonnes btw!

[sigurd]

My wording was bad in the above attemted joke.

Yes, I asked for the flying control unit weight. Since these are motorsailers, and probably seldom are fighting to keep a kite aloft, 5kg is probably not a noticeable extra weight. And as you say the kite itself is a huge, heavy thing so 5kg will drown in the noise so to speak. Even if I scaled the blackbox weight to the kite areas I'm used to, it would hardly be a party killer.

Thanks for the info, I'm very interested.

The type of line used is also interesting. For 300-600kg strength kitelines, linear spectra with a very tight spectra sheath is generally thought to have very good strength, weight and low drag, owing to the roundness, and the higher frequency (probably also lower amplitude) flutter than looser braids get (I think - from experience). As ropes get thicker, maybe other considerations change this?

[apex1]

Spectra or Dyneema it was, I know, but do´nt ask me for any data. And they made a hughe drama about the whole connecting "rope" including the power and data cable.

[mikeharwood]

Hello ,

I have been following this thread with great interest. I have come across a
kite that looks quite interesting, and am wondering what the thoughts of
those with more relevant experience might be ? I have no affiliations with
omega sails.

Regards
Mike Harwood

www.omegasails.com