new stuff in the a-class

[Doug Lord]

As far as I understand, if moveable parts on the foils had been authorized, we would have probably seen foils with hinge flaps like the Moth.

In this case, a pure L shape can make it, ant tooling is much cheaper than curved mould. actuation forces on a hinged flap are very different than those required to move the foil and/or its casing.

I think you are missing a fair amount of the picture. Read what I posted from Nathan O. Yes, you would save some money not having to make an L, but with the moth style system, the cost comes back with the control systems. Yes, there are some pretty simple wand systems out there, but, in a development class, you would end up with a simple system not being good enough and you end up with what the Moths have, with the ability to adjust ride height, wand length, wand gearing and probably more still. Overall, this adds significantly to the cost and I would guess that the end price between a moulded L and a Moth style set up means there would be little difference in price. On top of that, the systems need constant maintenance to keep working well enough for competitive sailing.
There is no cheap, easy way to get A's foiling properly. IMO, relaxing the rules a bit will simply lead to the boats costing another $5000. Increasing the weight limit won't help either, because once full on foiling, assuming you always have either 3 or 4 foils in the water, platform stiffness becomes key. This means that the boats will use up every bit of the weight on exotics, making the boat even more expensive.

Four foil systems or three foil systems with two main foils have been proven time and again to be slow on catamarans. The breakthru TNZ three foil configuration with a single main foil(and the hybrid foil to go along with it) have been a proven breakthru for catamaran speed on foils. A wand could be used on a single main foil(with the windward foil and wand retracted) but I'm not sure that it would be faster than the Groupama or Hydros system as they become more refined. It would, for the time being at least, be a lot easier to foil with the single main foil + wand.

 

[SimonN]

doug

I wasn't even discussing whether 3 or 4 foil systems are quicker. I was discussing platform stiffness and was pointing out that as soon as you have more than 2 foils in the water, platform stiffness becomes important. It is only not important of the foils are on the same hull.

But seeing you have opened that can of worms.........

The difference between an A and the AC72's and C Class, is that the A is sailed by one person. therefore, everything has to be done by that one person. Even with the best current systems, such as lifting the new windward board by linking it to the trap wire, take crew time to tack and the question we have been discussing is just how much longer it will take if you are having to tack boards. 5 seconds longer in a tack is equal to at least 60 metres on a beat if you simply hit the corner. Add a shift or 2, its easy to see you losing well over 100 metres on tacking alone. Now, this just guessing, based on discussions with guys who have won the A Class Worlds, Europeans and Oz Nationals (what would they know? ), but the point is that we think you are looking at an upwind increase in speed of at least 10% across the wind range. So the question is whether it might be that there is another way, where you leave the windward one down but you manage to get it into a low drag mode (no lift) when you tack, maybe by simply rigging it so when you pull on the trap, it alters the AoA of the board.

The bottom line is that the game has changed and there are now more unknowns. While I personally doubt that leaving both main foils down all the time will be the answer, it's way too soon to dismiss this as an idea for the A and maybe even for other classes. I believe Dr Bradfield had some success with multis that had the 2 main foils down at all times. We have no idea whether we would have had a different solution in the AC72's if they had been allowed to keep both main foils down all the time. What needs to be accepted is that there is no certainty that the fastest straight line solution is the fastest way to get around the course. Hydros and Groupama showed us that.

Interesting times and lots to play with. And I mean this in the most sincere way (not having a go), but there is so much going on Doug, why don't you really get involved. You really will get so much more pleasure out of it that way.

 

[SimonN]

http://www.moth-sailing.org/download/MTH2013CR220313.pdf

12.2 In alteration to RRS 52, only remote controls using stored power are prohibited.

Thanks for that. My copy and the Moth class website I checked on have a different version. I stopped keeping up with the Moth rules when I sold mine in 2009. I am still not certain that this needed to allow standard a=wands, but with my friends who know being away at the Moth worlds at the moment, I cannot check. the reason for my doubt is that the C Class has no such rule and some of them have played with wands recently (at least Fred and Blunted) Of course, the C Class website might have the wrong rules (I got bitten by that already today!!) or there might be some other provision to allow it, but I suspect that they wouldn't have been playing with something that wasn't allowed.

 

[Foghorn77]

So all of these kids that will be flocking to the A class to foil also have a spare $40k lying around and that's why the rule should be changed? I think you may be hypothesizing a bit much. There aren't very many kids in A class now and it's one of the fastest classes on the water, that's attractive in it's own right, but...

I'd be interested to know how many people replying to this thread have paid their A class dues this year, or ever. Maybe 1/2.

 

[Doug Lord]

doug

I wasn't even discussing whether 3 or 4 foil systems are quicker. I was discussing platform stiffness and was pointing out that as soon as you have more than 2 foils in the water, platform stiffness becomes important. It is only not important of the foils are on the same hull.

But seeing you have opened that can of worms.........

The difference between an A and the AC72's and C Class, is that the A is sailed by one person. therefore, everything has to be done by that one person. Even with the best current systems, such as lifting the new windward board by linking it to the trap wire, take crew time to tack and the question we have been discussing is just how much longer it will take if you are having to tack boards. 5 seconds longer in a tack is equal to at least 60 metres on a beat if you simply hit the corner. Add a shift or 2, its easy to see you losing well over 100 metres on tacking alone. Now, this just guessing, based on discussions with guys who have won the A Class Worlds, Europeans and Oz Nationals (what would they know? ), but the point is that we think you are looking at an upwind increase in speed of at least 10% across the wind range. So the question is whether it might be that there is another way, where you leave the windward one down but you manage to get it into a low drag mode (no lift) when you tack, maybe by simply rigging it so when you pull on the trap, it alters the AoA of the board.

The bottom line is that the game has changed and there are now more unknowns. While I personally doubt that leaving both main foils down all the time will be the answer, it's way too soon to dismiss this as an idea for the A and maybe even for other classes. I believe Dr Bradfield had some success with multis that had the 2 main foils down at all times. We have no idea whether we would have had a different solution in the AC72's if they had been allowed to keep both main foils down all the time. What needs to be accepted is that there is no certainty that the fastest straight line solution is the fastest way to get around the course. Hydros and Groupama showed us that.

Interesting times and lots to play with. And I mean this in the most sincere way (not having a go), but there is so much going on Doug, why don't you really get involved. You really will get so much more pleasure out of it that way.

Simon, I am involved and have been for some time-not specifically with the A class but with catamaran foiling.

-----

Bradfield's foilers were oversquare trimarans and his system is suited to that particular type of multihull because using the foils for RM on a cat with a "conventional" beam doesn't work very well because the foils have to work too hard. It's the oversquare beam that makes that system viable.

Bradfields oversquare Osprey is the best boat he ever did(18' LOA X 22' wide) but I'm not as convinced(anymore) of the viability of that system in light to moderate air around a course as I once was. I think getting down to a single main foil with a wand for a "sport" boat for ease of foiling and a refinement of the Hydros/Groupama system for a race boat may be the way to go. We'll see.

As a lover and follower of the A Class for many years I'd hate to see the class miss out on foiler development but I don't see the will in the class to do what will be required to take advantage of the current situation. I think ITA is wrong when he says the time is not right now-it couldn't be more right.

Regardless of what the A Class does there will be-probably- several singlehanded and doublehanded foiling cats fairly soon.

I think the most important thing for the A Class is to stick to the tried and true process of amending rules within the class should the class want to go in that direction. Even though I'm convinced that foiling is the future in small multihulls I'm not advocating that the A Class drop everything and convert to foils. An excellent foiler should probably be designed from scratch as a foiler, not be converted from an existing boat.

So I'm for whatever the A Class decides to do within it's class rules structure.

 

[SimonN]

Simon, I am involved and have been for some time-not specifically with the A class but with catamaran foiling.

Doug

In 6 years I have been on this forum, you have repeatedly said you are doing things and nothing has happened. We have the great and the good coming on these forums opening up about what they are doing and we see people who actually build stuff and get it on the water. What we don't get is people spouting off and showing nothing, except for you. A few sketches doesn't amount to being involved, and don't come out with your usual defence that you can't say anything because it is all "hush hush". There really does come a time where you need to put up or shut up. 6 years is more than enough.

 

[BalticBandit]

Doug do you even realize that being "oversquare" has no bearing on anything once you are foiling

there is nothing magical about "oversquare" other than perhaps it being evidence of inefficient "archemdian mode" hull design (ie you are needing more power and hence more RM to get the same speed on a hull that a non "oversquare" boat gets with a better rig))

Same goes for you ludicrous "opti foiler for kids" - foilborne stability is in part based on the throw length of the foils (that's part of why the moths go to a gantry for their rudders) so an "opti sized" foiler would be less stable than a moth. That' just perfect for kids (clearly you've never raised mushrooms much less kids)

 

[Catnewbie]

Hi Simon,

Sorry for my bad English, what I meant was that a L foil with 2 straight parts put at 90° would involve a much cheaper tooling than the multi-curved board we can see here or there.

If ETNZ go another way it was to comply with the rule prohibiting moveable parts on the foils as explained by M&M.

In other words: a L foil with moveable parts can achieve similar stability than the current ETNZ concept, but it would not be self stabilizing. A control system is required.

Controlling the moveable parts can be done with basic "inertial" system moving inside the vertical strut of the L board, without any wand. Just a spring you can adjust the pre-bend with a screw at the top.

As everybody seems to complain about the cost linked to the minimum weight, because light is expensive, I thought adding 5 kg at the weight limit would make a consistant package while deleting all anti-foiling rules and therefore alleviating some construction issue.

Regarding the cost, I though labor+vacuum+ heating were much more important than carbon/resin price, So I dont think 5 kg of carbon including epoxy resin will significantly increase the cost, but if you said differently, that's because you are probably an expert, or at least more expert than me.

You 're right Foghorn77 , I did'nt pay my fees these last years, as I do not sail, my A-Cat platform was already out-dated when I bough it, and I think it doesn't deserve to drive hours on motorway with the trailer to sail such a dog.

In sailing costs, you must consider all costs, just like a LLC with its income statments, and you'll see that if not marginal, the cost of the boat is just a part of the total cost, depend how much you sell her on the second-hand market of course.

ITA16, instead of repeating this 20 years old comedy as you did with the weight limit, bursting balls to Greg Goodall & Boyer. You should better look at another market, I mean A-Cat full glass-polyester and aluminium spars & beam, you could create a junior cheap A-Cat which could meet some obvious demand.

You are in the best position to make it, and I m sure you can post a retail price estimation on this forum within a few hours.

I guess you could make it at 6000€ + VAT, that 's probably what the youngest are waiting for, but move your ass, because some Thai commpany will make it sooner or later.

Cheers

W

 

[Doug Lord]

Simon, I am involved and have been for some time-not specifically with the A class but with catamaran foiling.

Doug

In 6 years I have been on this forum, you have repeatedly said you are doing things and nothing has happened. We have the great and the good coming on these forums opening up about what they are doing and we see people who actually build stuff and get it on the water. What we don't get is people spouting off and showing nothing, except for you. A few sketches doesn't amount to being involved, and don't come out with your usual defence that you can't say anything because it is all "hush hush". There really does come a time where you need to put up or shut up. 6 years is more than enough.

Simon, your hijack of the A Class thread to start a bullshit conversation about me is disgusting. Your misrepresentation of what I'm doing or have done is just pitiful. When you are backed into a corner you always lash out-you've done it in the AC threads where you spouted bullshit and I called you on it and you've done it here as well.

I've been working to develop a new kind of trimaran foiler using a unique foil system never before used on a trimaran. If it works it will be a contribution to the design of multifoilers-particularly small trimarans. I'm building an exact scale-very large- RC version of an 18 footer using this system. I've worked with a cat manufacturer to help develop a 16' cat foiler using a unique foil system.

So I am deeply involved in multifoiler design and development-and have been for some time.

What kind of new design/development have you done on multifoiler design?

By the way, your attempted hijack of this thread just ended.

 

[Doug Lord]

Doug do you even realize that being "oversquare" has no bearing on anything once you are foiling

there is nothing magical about "oversquare" other than perhaps it being evidence of inefficient "archemdian mode" hull design (ie you are needing more power and hence more RM to get the same speed on a hull that a non "oversquare" boat gets with a better rig))

Same goes for you ludicrous "opti foiler for kids" - foilborne stability is in part based on the throw length of the foils (that's part of why the moths go to a gantry for their rudders) so an "opti sized" foiler would be less stable than a moth. That' just perfect for kids (clearly you've never raised mushrooms much less kids)

Nonsense! On a Bradfield type foiler where the foils develop all the RM for the boat, the further away from each other the two main foils are the less load on both of them due to the development of righting moment. Major design element of such a foiler. And not a good system-or even a viable system for an A Class cat.

And on a surface piercing foiler, with a configuration like Hydroptere, the oversquare beam helps to assure sufficient RM allowing the foil centers of lift to be further apart and the waterballast CG to be further from the center of lift of the foils.

--------

More nonsense. The foiler for kids is not my idea-it is Jimmy Spithills idea. I have never said that he was talking about an "opti sized foiler"-I said that he was talking about a foiler for the size kid that would sail an Opti. The boat would be significantly longer than an Opti-particularly if it was a multifoiler.

 

[SimonN]

Simon, your hijack of the A Class thread to start a bullshit conversation about me is disgusting.

Doug

I find it hard to believe that you could accuse me of hijacking threads about the class I sail when it is you, a non sailor who doesn't sail the class who keeps coming on a bullshitting your way through about stuff you haven't got a clue. You did it with the Moths and scared away all the Moth sailors, including more than one world champion. Only last week the C Class guys warned you to back off (which you immediately ignored).

I will do you a deal. I will stop posting these truths about you if you stop posting on threads about stuff I am involved with. Go and start your own threads and I promise to leave you alone.

 

[Doug Lord]

Simon, your hijack of the A Class thread to start a bullshit conversation about me is disgusting.

Doug

I find it hard to believe that you could accuse me of hijacking threads about the class I sail when it is you, a non sailor who doesn't sail the class who keeps coming on a bullshitting your way through about stuff you haven't got a clue. You did it with the Moths and scared away all the Moth sailors, including more than one world champion. Only last week the C Class guys warned you to back off (which you immediately ignored).

I will do you a deal. I will stop posting these truths about you if you stop posting on threads about stuff I am involved with. Go and start your own threads and I promise to leave you alone.

When it comes to me all you know how to do is bullshit, Simon.

 

[SimonN]

I've been working to develop a new kind of trimaran foiler using a unique foil system never before used on a trimaran. If it works it will be a contribution to the design of multifoilers-particularly small trimarans. I'm building an exact scale-very large- RC version of an 18 footer using this system. I've worked with a cat manufacturer to help develop a 16' cat foiler using a unique foil system.

So I am deeply involved in multifoiler design and development-and have been for some time.

What kind of new design/development have you done on multifoiler design?

By the way, your attempted hijack of this thread just ended.

And just to be clear, this is exactly the sort of thing that I am talking about. For the whole time I have been on SA, you have made claims like this yet to date, we have seen nothing at all. You keep showing us little models, rarely if ever on the water, and you keep saying you are working with manufacturers, but you provide no evidence at all. You know you wouldn't accept that from anybody else posting, so why should we accept it from you? I have lost times people have said to you that you need to put up or shut up.

 

[SimonN]

Catnewbie

Don't worry about the English! It's always good to talk things through and at least we have a common language - A Class.

My real point about weight and cost really refers to what would happen if we did that and went full foiling. There isn't a lot of margin to build our boats down to weight and if we are full foiling, the platforms will have to be super stiff. Therefore, all I am saying is that it won't make things easier and instead, it will drive up prices.

As an aside, when it comes to pre-preg, the materials cost a bit more than the same stuff for wet lay up, consumables are more expensive but the labour is far less. An pre-preg A has something like AU$ 8000 worth of materials (last price checked 18 months ago) and I would expect that if you added 5 kgs of pre-preg and labour you are probably going to add $1000-1500 to the boat.

I don't always agree with Michele but I do share his concerns about not letting the class get any more expensive. I wouldn't change the rules to make it cheaper than it is today unless somebody comes up with a clever plan that retains the current performance. I think that horse is well gone and if you tried to do it, you would end up with a fair number of gandfathered boats that would dominate the fleet for years to come.

I am not overly concerned about foiling and the A Class, with the current rules, people will either come up with clever solutions or else it won't happen. Hopefully, with the slow rate of development, it might mean that those ways won't simply involve throwing money at the problem, money that has to be repaid through higher costs.

 

[Phat Buoy]

Assuming the class restriction on foiling was removed, does the A-class actually have enough horsepower to foil consistently, like an AC72?

If so, what would the platform, and its foils, look like?

Having just sat through another Bathurst 1000 (Australia's #1 car race for the Europeans and Americans), I am reminded of the Mazda RX7s during the old Group-C days. The RX7s had the handling and the power to beat the V8s on the flat tracks, but the rotary engine didn't have the torque to climb the mountain and they got smashed every October.

In terms of trying to win a race, foiling seems a bit pointless of you are either bouncing up and down on and off the foil, or 'stable' foiling off on a useless angle.

Are all these arguments about foiling a bit academic on a short windward/leeward course? Perhaps all the foiling advocates out there in SA land could crowd fund a de-restricted foiling A-Cat in order to demonstrate how much faster it is around the track?

Given the A-cat only has 150 sq ft of sail area including the mast (ie. bugger all), lets see how the ultimate foiler would look.

 

[Francis Vaughan]

It strikes me that the place to look towards an off the beach foiling development class isn't the A, but rather the B. Or at least a slightly modified B rule. Apart from the Tornado, the B was a failure, and I would say that a huge part of that was the beam. You can't tow a B class without serious pain. So, modify the B rule to tow width, and set the rest of the rules up to be box, sensible minimum weight, and otherwise open enough to allow foil developments. Of coarse it will be significantly more expensive than an A, but not wildly so (not like a C) and for those that want to play with foiling, they can do so without splitting the A fleet. On the other hand, I doubt it will actually happen. The simple lack of any boats at all to sail against makes this a very steep hill to climb. You would need a few rich and enthusiastic guys at one club to get the ball rolling. But a smaller than C class two man open development class with reasonable sail area is probably what is needed to get foiling really working, whilst the A is just going to be a real mess. I suspect it is too early to push one design or production classes - too much still to learn - so these boats will be obsolete about the time they leave the factory.

 

[Fireball]

The Formula 14 has a very clean box rule: http://www.formula14.yachting.org.au/

You can have any sort of foil you like. They can even extend past the beam of the hulls. There's a spinnaker/screecher for downwind.

They mostly seem to have been singlehanders, but even that is not required by the class rules.

 

[ita 16]

this forum is very attractive, many intelligent comments and useful to all "builders and buyer's" excluded catnewbye alone continues his old stupid and senseless war "please catnewbye" forget that I exist.
to clarify my earlier speech: with 5kg more we can have a class A with foil without compromising the structure and costs of the boats current, so the only cost increase is due only to the system of foil; also limiting materials such as the honeycomb and the pre-preg hulls there would be a reduction in costs equal to the increase in costs caused by the foil, I say this because it is demonstrated that the honeycomb has serious problems of delamination etc. and combined with the pre-preg have a high cost in proportion to the increase in performance of the boat (see what published by the guys of the Vision on the Dutch website),in this way we will have a class A flying without increasing costs, so we spend best our money for higher performance of the boat.
in the future if we decide to fly with the class A would remove all rules that prevent you from doing this, but currently there are obvious economic problems and has not yet been shown that the class A can fly well and safely, for this reason I believe it is an enormous risk to make this big jump, now would modify the current rules that can quickly create complex and costly systems to fly (flight not satisfactory) our boats.
in the meantime other teams and also I will continue to do tests and to seek better solutions to fly the class A.
regards Michele

 

[SimonN]

Michele

You keep going on about banning pre-preg and honeycomb, but your facts are simply wrong. Just because some people have delam issues with honeycomb doesn't mean that well built boats will have. I built my first honeycomb boat is 1982 (yes, wet lay up) and never had delam issues. In more recent times, come down here and look at the latest fleet of 18' skiffs, which have a great builder in Bret Van Munster. The top boat for the last 5 years has only just replaced their hull and delam isn't an issue they have to deal with. Anybody who is buying boats that delam should be having very serious words with their boat builder and should be telling the whole world what is going on because there is no excuse for it.

As for cost, again, I cannot agree, if you know what you are doing. Yes, honeycomb costs a reasonable amount more (IIRC, about $1200 compared with foam) and it allows you to use more material where it really counts, the equivalent of about 200gsm of cloth over the whole of each hull. Of course, you may not want to use it in that way, nut that is the order of magnitude. However, the real point is that if yo are set up for pre-preg production, the labour costs, compared with wet lay up, comes down significantly. And done right, you end up with a far better platform. You should see the Paradox. Shame it isn't yet performing, but that is so well built, so strong, such a stiff platform and overall, very, very impressive. Or if you want to see another good nomex platform and one that is very reasonably priced, look at the Exploder. Those boats will remain strong enough for years. in fact, in other classes, I know 20 year old honeycomb boats that are still as strong today as when they were built.

Overall, the price difference is small compared with the added benefit. And if people try to say different, then they don't understand. Yes, there is a problem that a few boatbuilders (one in particular) charges silly money for their boats, but they charged far more than everybody else back in the day before they went to pre-preg and nomex.

I see 4-5 year old wet lay up, foam boats and compare them with the same aged pre-preg boats. One you could still win the worlds with, the other is close to the point of not even being worth taking to the worlds unless you expect to finish in the bottom half of the fleet. In the long run, strong platforms pay for themselves, which is why people are getting good money for DNA's which are 3 years old or more.

The bottom line is simple. You can build A's out of pre-preg carbon honeycomb that are stronger than wet lay up boast, which will last longer and which are more than capable of standing up to the way they are used. Banning pre-preg and nomex may bring down the price of a new boat slightly, but when you look at the total cost, including depreciation, it will work out better in the long run.

There is only one problem that I see from these boats. It is a fact that as boats get old and designs change, they get handed down to people who probably don't look after the boat as well as when the boats were new. Start running the boat up the beach and things like that and you will have issues. Look after it right, and all will be good.

However, I do believe we agree on what is best for the class regarding foiling, and for all of our differences, we should celebrate our common love of the class and we both want the best for the class.

 

[ita 16]

I do not want endless controversy with you, I have no time and it is not constructive for the reader,. I know what I say because I did class A pre-preg (not dinghy or skiff) about 8 years ago (so long before of the current trend), I use of pre-preg every day, I know perfectly this technology, so please do not offend "it's my job not yours. "
from what you write I sense that you have not read this article http://www.a-cat.nl/a-cat/a-class-european-championship-2012/!
I also believe that you do not evaluate the very high costs to build molds and models suitable to this production process, depreciation costs of autoclaves and ovens, etc., plus other expenses for surface finish and painting post building and many other things.
then if you compare the stiffness and long life of the current boats built with these two different systems surely will not see big differences, indeed very small.

we both want to do good to this class.

greetings