I suppose most have seen the A-cat wing buildt by Ben Hall after input from the Cogito team. There is a thread on it in the open forum, but it seems like there have been a bit too much F-16 talk and F-16 members being too vocal "out there" <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> so I'll ask my questions here instead.

I wonder what the lift to drag ratio for a wing is compared to a wingmast with soft sail. I know the theorethical gains are on an order of 2-3, but I dont know about practical use.
In real world, how much faster would a wing make an F-16 upwind?


Since the wing dont have a mainsheet, just an AoA adjustment, would it be a challenge to reinforce the wing for spinnaker use? All forces would have to go down the stays, but since the wing have a larger crossection than a mast.. Wouter?

The F-16 rules specify a soft sail. But if the A-cat wing testing proves the wing to be both practical and robust. How about it? What are people thinking when they see this? I know Timbo is a supporter of wings <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />


I think Ben Halls wing project is really cool. If it proves both fast and robust, I would be interested in playing with wings (might even have some fun with wings anyway, just for fun, when other projects are finished).

I'd like to see if I understand the principle of the thing... Is the issue that with a soft sail, as the speed of the air over the sail increases, part of the available energy gets lost deforming the sail surface, but that a solid wing doesn't deform as much and so more energy gets translated into lift?

Personally I think this is a really interesting project (perfect for A Class, as others have pointed out) and one we should all keep an eye on, but considering the general philosophy of formula sailing ("mildly restricted class rules indicative of a controlled development class... small advancements in handling and general behaviour of the designs are allowed") I don't anticipate a move away from soft sails for existing formula classes in the near term.

1.4.4 The distance, at right angles to the mast axis, measured around and back to the same point is referred to as the "mast circumference". The mast circumference shall not be more than 0.500 m.

This is box rule 1.4.4 of the F16 class. It is not possible to make a wing with a circumference more than half a meter.

That's besides all the technical problems there will be in sailing behaviour, but it is always possible to have a try.

Regards,
Hans

Hans, this is just for fun, toying with the idea. If we as a class want to go that direction we would need to change the rules and vote over it of course. I just want to hear what others think about these things.

Mark, the wing dont deform as much as a sail, the pressure differences are larger for less drag and you can avoid the separation bubble just behind the mast on the windward side (you get those even with wingmasts).

Absolutely. I was just trying to preempt anyone who might be thinking it could be possible at some point in the future to change the rule (Rolf seemed to be entertaining such an idea) by pointing out that you also run into the basic class philosophy expressed in 2.3.1.

The rig I have provides me with enough challenges! I'll leave wings to the more capable and adventurou$. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> They're neat to look at though and I'm certainly not opposed to them.

I know it is just for fun Rolf, but people don't always read what is mentioned the comment was only to prevent a heavy discussion, maybe people start to think we want to change the rules because of this wing on the A.

It is by the way not new that this is tried out on the A class there was a Swiss guy i think in 1988, who did try it. But it did not work, weight and trimming was a big problem and special on the downwind leg. I hope Ben will sail it at the worlds so i have a better look at it.

Regards,
Hans

Every few years someone comes out with a wing. Given the advancement in sail and mast materials, the added advantage of a solid foil has to be much less than it used to be. The other issue is that to gain the full advantage of this type of addition (also holds true for foils, but even more so) the other limiting factors of the box rule like beam and length really hinder the true potential of the feature.

Intial test have shown the wing is faster in certain conditions and cretain point s of sail. It is also more difficult to set up, some more expensive and restricts the boat even more in what conditions it can be used. Ben will have it at Worlds. Over a wide range of conditions I do not feel it is flexible enough to anything more than a very large topic of discussion at the event. Long term the class will continue as it has in the past.

My $.02,(.005 Euro) but it interesting to watch .

Matt

Why do select numer of people insist on requiring a "Class" to develope their concepts?

No one is stopping anyone from taking a boat and adding foils, wings, or any number of other mdifications. If you can make it work, great, start your own class.

Most people can not admit that they are the issue with their getting better results in their sailing. It has to be the result of their boat, or their rake, or thier weight, not the fact they are not as good a sailor as the person who beat them. A class needs at least some consistancy to grow. I am all for radical ideas and development, but it does not mesh with a large class organization. I love the F16 concept and would like to see a world wide class not just a few guys tinkering in their garrage.

You want to get really radical, there is a group for you. Give Steve Clark a call and get into the C class.

I don't see a problem here. On conventional masts the bending of the top is necessary to get control over the draft and twist of the sail high up. Ergo the hound fittings can not be placed to high on the mast. Especially not since that aggrevated the bending of the mast in the middle (spreaders) where you actually don't want it to bend.

With a wingsail you can relieved of that necessity and so you can place the hound fittings at the spinnaker gate if you want to. As such all the spi loads will go down the stayes as addited tension and down the mast as compression; you have lost the much more damaging bend loads.

With this you just need to make sure the stays themselves and the attachment points on the hull can take the new loads and you are done. I dare venture that the basic 4mm 1x19 and attachment points I have now are sufficient to handle this already.

Wouter

When Phill Brander, Kirt Simmons and myself wrote and perfected the class rules, making use of many good suggestions by the early F16 sailors, we actively ruled out a wing sail. This is not to say that we intended it to stay forbidden for ever.

I think we all saw the class rules as a living thing and understand that at times the class rules need to be amended to garantee the continued succes of the class, just as much as disallowing things is required at times to garantee the same.

Additionally it was considered valuable to allow experiments in a controlled environment so they could both proof or disproof themselves. I feel Rolf has understood that part of the F16 rules very well. He even mentioned it himself during the T-foil discussions of several months back.

Basically the construct was a follows. Elements that were considered prohibitively expensive, cumbersome or inaccessible to the large majority of the F16 target group were banned by the rules. Wingsails were on of them. Elements that were expected to become practical, affordable and accessible within a relatively short time frame were allowed. The latter included carbon masts and T-foil rudders as well as the general use of carbon, kevlar and high performance sail cloths like cuben fibre and the "sail drive" laminates. One could say the class was geared towards making the most of the refinements encountered during its first decade.

A provision was added where an experimental craft deploying an outlawed component could be allowed to enter F16 races and possible be scored as well. An official request to the local F16 head or the International body is required for that and these may turn down your request if they feel that there is a good reason to do so. This provision is included to allow geeks to try out new stuff on the F16's. The deal they can get is that if they can proof it to work, to be affordable and accessible to the large majority of F16 sailors then a F16 rule change may follow.

This concept is fully intended to avoid losing the game in the future as some classes did when the asymmetric spinnaker was introduced on cats. If such a development comes along in the future then I feel the F16 class such serious consider adopting it.

Basically you sometimes have to go with the times (adopt new technologies) for survival even if that means a temporary setback to the class.

If you want to see what happens when you don't do this then look at the Unicorns, Old Tornado's, Taipans and Spitfires. Brilliant craft in their own right, but nevertheless they are losing the game against never designs that can make use of the improvements made since these classes were launched.

But even more importantly I believe that the F16's as they are now are pretty efficient already. As such I believe 90% of the hot topics like full foiling and the wingsail will fall down when put to the test against well designed conventional boats. When that happens then the whole discussion becomes mute and such a thing can be extremely healthy to the class as you have ended the discussion beyond any doubt, second guessing or hard feelings.

What I'm trying to say here is that it may actually be alot smarter to allow such things as the wingsail to be tested inside your class structure (but in a controlled manner) then disallowing it upfront. It was this realisation that lead to the open structure in the class rules (we allow alot of things and materials while others except the A's simply don't) and the provision (even stimulation) of testing new concepts on the F16's against conventional F16's.

And to finish this line of reasoning off. I found new developments and their testing to be a promotional gift from God. Every sailor out there loves to read about new stuff and do comparisons between old and new. It also gives the class a very "can do" mentality that many sailors appreciate. You attract the brightest minds and most proliferic homebuilders to your class. You get awarded with a thriving class with many active members and a well respected stature in the catamaran scene. All of these are worth alot of temporary setbacks when you have to make a choice between them. However, often you don't need to choose between these and with careful guidence they can be made to enchance one another.

An example of the last is the creation of a healthy turn-over of boats. I refer to my departing brief for more info on that. Slow development (= slow outdating of boats) is GOOD ! Because it takes long enough for a boat to become outdated and uncompetitive, but when it does it becomes a very attractively prices entry point for newbies who will not be held back much at all by a small technical disadvantages when they still have to learn so much. Take a look at the F18's for an example of that. Nacra Inter 18's won't win you a World or European championship but it does bring in lots of new members to the class and keeps boat builders afloat through spare parts.


So Rolf if you want to, then go ahead. You got my help !

Just make sure that practicallity, affordability, accessibility are included in the design stages or just accept your setup will not be awarded an "experimental dispensation"


And just to make perfectly clear; an craft on an "experimental dispensation" can never become an F16 champion even though he may be scored 1st. The dispensation is only there to proof yourself and your concept in the large fleet, not as a "cheat route to a championship".

Wouter

My reaction would be that I'd love to give it a try, but I do not have 200 hours spare to build one (time was quoted on a Sailing Anarchy thread on this A class wing).

My second reaction is I'd hate to see what would happen to the rig if you wash it while sailing in waves and 25kts of wind.

My third reaction is. Lets watch with interest and see what happens. Maybe one day, but not in the forseable future.

Let people with fuller pockets develop it and then see what happens. Flying a kite off it might also be an "interesting exercise".






People my jump and ask why I don't want to ban this like variable trim rudders. The simple reason is that this may well be retro-fittable to current platfrom, where as my research shows that the variable trim issue would cause us to redesign our boats totally.

The thing I am interested in is how much or little pressure is on the wing "main sheet".. The old wrist gives up around 30 minutes on the water after the wrist reconstruction.. I believe Miss Nylex also had a 2:1 main..

The issue is mounting a kite.. and how that will change the main characteristics.. How a wing will take the kite loads etc..

One the development side.. I fully expect the wing will be banned in F16 asap.. As soon as one appears..
You must admit we have had this tendency even under your chairmanship..

I admit that we had our disagreements in the past about what could be allowed and what shouldn't. On the other hand have you checked who kept the carbon masts in the F16 class, the carbon beams, the Kevlar, nomex and all other kinds of materials like Cuben Fibre ? And lets not forget the T-foils and even the banana boards and canted boards !

Yes. under my tenure the glueing in of the beams was forbidden. So too continiously adjustment of the mast rake and the ability to rake the mast to windward. And a mast height limit was introduced into the class rules.

Looking over this comparison I say my rep sheet is pretty favourable in the way of allowing new
stuff.

With respect to the wing if the choice was out to me then I would look closely at its survivability, rightability when singlehanding, it performance (gain ?), how practical it is in transport and its costs. If a favourable judgement can be passed on all of these points then yes I think I'll be a long way towards being convinced that it should be allowed. Still, I don't expect this to happen in reality, mostly I expect the gains made by the wing around the bouys in a fleet to be to small to really be attractive when compared to the ease of the conventional rig.

So like others I don't see introduced to the F16's any time soon.

Wouter

**chuckles** not that we don't trim the boat by weight distribution now..

Thanks for the chuckle.. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Rolf,
I agree with Hans.
Talk about wings and the pros and conns but once you start talking about putting them on an F16 it is bad for the class's image.
It undermines confidence in the stability of the class rules.

The wing is clearly and intentionally outside the rules and any boat with such a fixture could not be called an F16.

Add two feet to your hulls, and you can within the class1 18sq rules, have a legal craft. Although many believe it was Wild Turkey's wing that significantly contributed to the loss of interest in the class1 18sq class.

You have a class in it's infantasy, with a hand full of boats being sailed around the world, still looking for main player manufactures to get involved,you have countries with out associations, a country with 20 boats sailing under the radar and there is talk of adding a wing to the rules.

It dosn't even make interesting reading.

TJ

Then feel free to move along.

All interesting reactions to what I tought was a fun question to tumble around with.
Once it is clear a wing is against the class rules, I dont see the harm in discussing the pros and cons of a wing. I firmly believe in open discussion and information exchange, even in the ugly face of politics. Philosophically, some of the opinions voiced here saying that discussion of a topic is damaging for the class is pretty interesting. Especially so considering the virtues modern western society was tufted on and what happens when we deviate from these ideals. Enough said about that, but I fear we will have an ideological showdown sometime in the future.


Matt M, congratulations on being selected for building the moulds and hulls of Bens new boat. It must have been very interesting to be part of this project.
Your and Hans points on downscaling problems is good information. I guess we all will follow Ben as closely as possible at the worlds. Part of my question was just how much more efficient would a wing be today against current rigs. You pretty much answered that, and we will see the results from the litmus test shortly. Interesting times..

The history of modern western society also demonstrates how easily people misunderstand each other.