Fixed Winged Cat

[jjtctaylor]

David,

I agree on all points. Need to engineer out the failure points. The wing should be demountable by the crew without help from the yard. Need to eliminate all the other typical sail failure modes. Ripped sails, stuck in mast furling, broken stays, worn lines, broken winches. Plus reduce the maintenance for all this to nearly ZERO. The only possible problem with the wing might be worn linkage to the tail rudder. Might have to look at that every 5 years.

REgards,

JT

[David M]

Originally Posted by jjtctaylor

David,

I agree on all points. Need to engineer out the failure points. The wing should be demountable by the crew without help from the yard. Need to eliminate all the other typical sail failure modes. Ripped sails, stuck in mast furling, broken stays, worn lines, broken winches. Plus reduce the maintenance for all this to nearly ZERO. The only possible problem with the wing might be worn linkage to the tail rudder. Might have to look at that every 5 years.

REgards,

JT

I do wish you the best with your idea. I hope I did not come across as a complete pessimist. I was throwing out ideas on why it might not suit cruisers. If you can overcome those perceived negatives and any actual negatives then that would be exceptional. The more alternatives there are to anything then the better off everyone is. Choice is a good thing.

I don't know why you started this thread, so I will assume it is for your financial betterment. There is nothing wrong with that if that's the case. Given that assumption, I have to say the following:

I have to tell you that cruisers are rather conservative. I am not referring to ones political ideology when I say conservative. What I do mean is that most cruisers like to stick to what has worked for a long time. Because something is new does not necessarily mean it is better. Additionally, many cruisers have a large percentage of their net worth tied up in their boats and they are not about to risk their boats value with something that might not work for them or cause their boats to take a big hit in its value because very few buyers want a wing sail.

I think you have a long road ahead of you in convincing cruisers that this is a better technology than conventional sails and rigs. Cruisers will want to see others that have used a wing sails successfully for many years before considering the purchase of a wing sail for themselves.

I think you may be approaching this in the wrong way. You are asking people to blindly accept that an untested new idea is going to work for them. Getting people to accept that a relatively untested design is going to work for them is not going to work at all. That's not how people think. People like to see how something has worked over a good period of time and then they consider adopting the idea for themselves. I know developers of prototypes would much rather have the future owners put their own money up front rather then putting at risk the developers own capital. Unfortunately for the developer, the future owner sees it differently. Why risk his capital on a relatively untested idea? You, or the developer, are the ones who are going to have to your capital at risk in order to see this idea come to fruition.

What may work for you is putting together a small fleet of wing sail boats, paid for by the developer of course. Get those boats out on the water to show the world just how good they are. Your own small fleet will also provide for necessary beta testing to make them a better product before putting them on the market. People will notice your boats because they are very different.

What may also work is for a new owner and the developer to share the risk. The developer partially pays for the cost of the boat and the new owner pays for the rest of the cost of the boat with the understanding that the boat is to be used as a test platform for the developer with the caveat that the owner has 100% ownership in the boat.

If the wing sail is indeed a better or equal technology then it will sell.

Good luck with it. I truly mean that.

[Lodesman]

What about "soft" wingsails? Best of both worlds? Omer wing sail - soft and variable wing sail

[jjtctaylor]

Thanks David.

You are absolutely correct. To change what has slowly evolved over thousands of years will not be easy. It is not my desire to make a change that offers no real benefits but really to inspire new opportunities for recreational users to go boating with high reliability and ease of use. I want a "green" system where the owner can focus on seamanship and surroundings with less effort on getting the whole boat to "GO".

Never want to replace sails as there is an art and confidence in managing the rig, but for so many that isn't as important.

Safety, reiliability, performance and cost are my key drivers. I will hope to bring finished product to Annapolis. If not to enter as commercial product, maybe just sail around and torment Lagoon, Fountaine Pajot,...... and all their friends.

Please if any on the forum have ideas, recommendations, or barriers to try wings as sail alternative please keep adding on this thread. Cost and maintenance in far places are good points.

Best Regards,

JT

[jjtctaylor]

Originally Posted by Lodesman

What about "soft" wingsails? Best of both worlds? Omer wing sail - soft and variable wing sail

The OMER sail has problems with narrow window for angle of attack. Way too much active management to make that system work well. If we can figure out a way to add a tail for active tracking then he might have a winner.

JT

[Aussiesuede]

Originally Posted by jjtctaylor

The OMER sail has problems with narrow window for angle of attack. Way too much active management to make that system work well. If we can figure out a way to add a tail for active tracking then he might have a winner.

JT

The first time I saw that design, my first thought was "where is the 'Aileron' on the trailing edge of the mainsail wing? Would seem to solve the issues with opening up the angle of attack. It doesn't seem like a difficult engineering feat to have a 'solid' sail track connected from the top of the mast to the trailing edge of the boom. Then at the end of the main boom have an articulated joint to which a 'mini boom (3 feet long)' is attached. That 'miniboom', and it's attached 'wing', would effectively act as an 'airleron' to most effectively adjust attack angle changes. Such a system would be less cumbersome than a traditional rig with greater ease of sail-handling and a more efficient airfoil.

The thing I like most about the Omer Sail approach, is that the it can be fully furled and as such I see promise with it's basic design being the most promising of the wing designs. No exotic materials, and a less cumbersome rig overall. If it gets gusty, a simple release of the mainsheet allows the rig to naturally relieve all counterforce and basically enter a 'stall' eliminating all lift - which is desirable in that instance on a cat. MOB? Again, release the mainsheet and hard rudder in the opposite direction of angle of attack - and you've basically got an 'emergency brake' that would leave you 'waddling'.

[jjtctaylor]

OMER has some level of complexity already. Personally I don't like things stuck on things, just because of surprises or unintended consequences. Wings are not a casual design. All kinds of surprises, like load balancing, etc. For instance if the center of wing rotation is too close to aileron or rudder, then the wing can create its own oscillation, swinging wildly between fore and aft angle of attack. The vibration created will shake the mast apart. For aircraft it is called the "death" flap. I do think it possible to modify the OMER rig but take care what you try.

Let me try a rigid wing first. why haul stuff up and down if you don't have to. I realize standard procedure is reef and reef early,....... If the rigid wings are not expensive and reefing simply a a tug on the tail rudder lever to reduce the angle of attack, then why go to the trouble of hauling up/down the OMER rig, plus wear and tear, maintenance and other associated effort.

UNless you like furling and its fun........

I would just suggest using a wing makes for a different set of nautical tools to make it GO in the direction and speed desired by the helm. Get to play pilot, with no ropes, wires, winches blocks and related hardware, just a single lever for forward and reverse, (left or right tack) When it's time to go home, put the tail in neutral, (Lock the lever) and go. Even on the hook the wing will add minimal drag, so won't make your sailing around the hook change any.

If you look at the "C" class cat rigs there is a bunch more complication that can be added for that extra tenths of water speed. WE cruisers don't need all that. Simple, reasonable performance in light to heavy air is the goal.

What do you think ?

JT

[Mark424]

Very interesting thread.

I must say that I'm a bit surprised by the negative reaction on a catamaran forum. It was only 25 years ago that all these same negative comments were almost universally made about catamarans, and many people still make them today. Just as with mono vs cat, the best thing about current rigs is that they are familiar - that doesn't mean they are better in any objective sense. Yes, cruisers are conservative, but I think we should all applaud and support those willing to challenge the status quo so that we may one day benefit from their efforts.

Derek Kelsall (one of the multihull pioneers) recently made a comment on another list about the detriment of current rig design. In the context of using kite sails: ([MHml] Kites, hull slenderness and weight and Kelsall formula.)

"Rob, I commend the effort and urge others to not be deterred from trying to perfect the kite. Those involved in speed sailing, kites, or rigs set up to act in the same way as a kite, (with foils) have always been seen as the ultimate in efficiency. Our 70’s, shoestring budget efforts showed potential. I remember most was how we never felt we had too much wind – no capsizing moment. For cruising sailors, kites, in the right form, should be applicable. Certainly a lot more to learn but I am confident that someone will get there – just keep trying. The big gain would be very low loading on the structure and hence even less weight – where the current typical cat rig goes entirely in the opposite direction. (Freewing Twins is another, very low load situation from the rig). The KISS multi and an efficient kite would make a great combination. Dave C is equally commended for his efforts."

The freewing Twins he refers to is I believe this boat Kelsall Catamarans - Sail Cat

Originally Posted by sandy daugherty

They should look for simple, robust structure that can be repaired at sea by a couple.

While a current rig might be simple compared to a computer controlled wing with tail, it's certainly not "simple" in any absolute sense or relative to a free standing rig like a wyliecat or Kelsall's Freewing.

Originally Posted by sandy daugherty

When I drop the anchor in some beautiful refuge, I do not want to worry about dragging that anchor because I have some aerodynamic surfaces still up, swinging in the breeze.

I hate to be the one to tell you, but you have a huge amount of aerodynamic surfaces up. The circular and near circular cross sections of your mast, standing rigging, running rigging, furled headsail(s) all create an enormous amount of drag and load on your hull and anchor. How the aerodynamic drag of a standard rig compares to a rotating wing mast or wing sail I couldn't guess, but would not be surprised if they are comparable.

On of the most compelling argument for some sort of free standing rig (sail, wing, or otherwise) is a tremendous amount of excess structural weight required to support the loads of a standard rig. Weight, especially in cats creates downward spiral, because you have more weight you need a bigger rig, which means you need more structure to support it, which means more weight. It seems that most wing sails have a more optimized sailshape and thus create the same about of force with a structure that is both shorter and less surface area. Both good things.

I'm also don't agree that cruisers don't care about speed. Yes, I don't need or want to go 30knots, The Dashew's have done a number of articles about the ability of speeds in the 10-14 knots improving comfort and safety (through the ability to get out of the way of weather). Many of the current heavy weight production cats just don't have these attributes.

[jjtctaylor]

I think the point being made by most is that it can work, it has worked, but will wings bring enough advantages to the table to stand the test of time.

Obviously the catamaran has survived due to it's stability and other attributes. I agree what is needed are more who will venture into the unknown to build the base of knowledge and experience with new technology. A free-standing wing rig was not possible in the past due to strength of materials. The weight added to the rig resulted in too much inertia aloft. That made the boat difficult to control in heavy seas.

The paradigm has shifted with the lighter new age materials, bringing this concept into the realm of practicality. I think it is time to try again to mainstream the concept.

Would be nice to hear from any who tried a rigid wingsail no matter what scale. Lot's of pundits, should be some with "C" class experience for ideas and concerns cruisers should know.

JT

[fixed wing]

Here are a few wings that have been built and are out sailing today

[sandy daugherty]

Sorry Mark, I'm not going to be painted into a corner by someone else, I reserve the right to do that myself! Wingsails are great. I would love to have one myself, on a big day sailor. There is a rich assortment of megabuck goldplaters here on the Right coast who need to be blown away by a much faster multihull. The only thing better would be a camera on a helicopter to put it on youtube.

I like to go very fast. I also like to cruise. These ideas are still somewhat mutually exclusive. Yes, in a perfect world they would not be, but I'm old and not prepared to wait. I don't want to see genius and resources wasted on Jules Verne dreams, I want to see them solving today's issues: universal access to accurate weather, fuel cells, renewable energy resources, and [please, please] a cure for arthritis!

Innovation has a very important place. See the quote above from Kelsall about kites. That looks good! But rethreshing old ideas isn't a good investment: new ideas are.

[Robertcateran]

Small planes fly at a 100knots. Their wings are not particularly robust. I would have thought that a wing has less drag than a stayed rig. The main difficulty I see is the possibility of oscillations if not properly balanced and the pitching motion of a boat would add much more stress on a wing than for a plane.

[jjtctaylor]

Agree any wing must be dynamically balanced. Typically there is an extension in front of the wing area to counteract the tail rudder weight. That said, even if it is balanced and the wing should not move to pitch roll or yaw motions, that does not preclude wing inertias from it's own weight and movement.

That inertia is an undesirable motion, best minimized by lighter wing fabrication. Typically that runs counter to robust build. Thus must concur that for cruisers there is not yet certainty, current strength of materials will achieve that desired balance of strength to weight ratio. There are other oscillations that are known as well, Karman effect, tip vortices with this Reynolds number, and harmonics that all have to minimized.

Obviously if it was easy then they would be everywhere by now. But I think with the experience of the "C" class boats, some proven wing structures can deliver on the promise. Just have to test our way to success. I believe the biggest challenge is the "effective" coefficient of lift better than a cloth sail with all it's proven advantages and warts.

Too much trash talking on several forums in this regard. Not a worthwhile discussion here, but that is the real issue. AND it's not enough to be better at a close reach,.... I prefer to sail downwind and on broad reach just because the ride is nicer.

In regard to basic question can a wing address the vibrations and be robust, I think it can be done. Must be proven in open water and documented.

JT

[SelkirkWind]

Originally Posted by jjtctaylor

David,

I agree on all points. Need to engineer out the failure points. The wing should be demountable by the crew without help from the yard. Need to eliminate all the other typical sail failure modes. Ripped sails, stuck in mast furling, broken stays, worn lines, broken winches. Plus reduce the maintenance for all this to nearly ZERO. The only possible problem with the wing might be worn linkage to the tail rudder. Might have to look at that every 5 years.

REgards,

JT

Gotta admit, I am one, and my reaction is I would LOVE to sail her just for the experience. If she does what they claim, I will be very impressed. Do I think the comments above are not valid? No chance, but......

[gramos]

Originally Posted by amarinesurveyor

They look kind of like the Walker Wingsail boats.

i remember seeing this boat in cowes, uk a few years ago and the whole rig had been ripped out of the coachroof ! , dont know what had happened ,but there was nothing left except a big hole !