A-class, "hydrofoils not permitted" violated?

I guess as the boats were measured at the latest event and allowed to sail they are not hydrofoils!!!!!!

It's going to be interesting to see how that turns out - certainly the rule could use some additional clarification. Again though, one sailor having good results isn't much of a definitive test.

I dont see what the fuss is all about. The Acat class bills itself as a development class, but the class is in a panic over banana boards. They were all in a panic over Ben's solid wing too and that didnt amount to anything significant. Is this a development class or not? If it is, then stop writing rules. If its not, then lock down the rule set so that all foils have to be straight.

Personally, I think the class should leave well enough alone.

They've restricted the underwater foils by max beam in the up and down position and restricted them underwater by not getting closer than 1.5m under the static waterline. The class doesnt need more rules.

Adding banana boards just makes this class more interesting. And its not going to add to the cost of a new boat by any material amount. $50 more carbon in a board isnt going to hurt anything.

Adding or reconfiguring the daggerboard trunks is also not that big of a deal.

Banana boards will probably make the boat more interesting, and faster. Whats wrong with that?

I say bring on the banana's!

It is quite difficult to get rid of hydrofoils in a sail craft, they are needed to keep forces in balance. Any underwater device capable of generating dynamic lift is a hydrofoil. Even the hull generates dynamic lift.

Common daggerboards (straight, vertical and with symetrical section) generate a vertical lift component when the boat heels: upwards if the hull has a bow up attitude, downwards with a bow down attitude.

Rudders also generate a vertical lift component when the boat heels: downwards with weather helm; upwards with lee helm.

What can possibly be banned in a class are

appendages that generate a dynamic lift force component along the axis perpendicular to the plane defined by the waterlines of the two hulls

.

Ok, so if my foils lift the boat in another plane, other than perpendicular, then I'm ok?

As you mentioned, all foils generate lift. Its going to be near impossible to regulate good lift vs bad lift.

Furthermore, the original intent of the hydrofoil rule was meant to prohibit was lifting both hulls clear of the water at the same time. If thats the intent, and thats what the rule is meant to prohibit then banana boards are legal.

Bill

That's what I remember too - like I said, a little clarification in the rule may be in order.

Exactly, the current wording actually banned daggerboards, rudders and hulls - and nobody noticed it.

The new definition would ban

appendages that generate a dynamic lift force component along the
axis perpendicular to the plane defined by the waterlines of the two hulls.

This bans everything that generates lift more or less in the same direction the mast points - even when the boat heels. The banana boards generate a lift component in this direction, so they would be banned. Normal daggerboards and rudders are aligned with this

mast

direction, so they don't generate any lift component in the direction

perpendicular to the plane defined by the boat's waterlines

, so they are allowed.

If you check the rules at ISAF or at the A-cat webpage there are no rule or measuring guideline that bans that the foils get closer than 1.5 meters. You can have them as close as you want!

/hakan

Someone must file a protest against the boat and as far as I know no one has bothered yet. But now the situation is a bit different and we might see protest from other sailors at the next big regatta.

/hakan

But their Daggerboards are NOT vertical and so they DO generate lift in that direction.

Hulls do not have VERTICAL sides and so they also create some lift (very small amount) in that direction also.

Very difficult rule to word correctly unless they specifically ban bendy boards.

But if a boat has passed measurement it's an A class; I'd expect you could protest that a boat no-longer is in the same state as it was when it was measured, but how can you protest that a boat that has a valid measurement cert is not an A class?, could open a massive can of worms if a boat is declared a valid A class (or any other class that

allows

them), and then protested and then declaired NOT at valid A class - this would potentially negate all measurement certificates and all measurement at the event for this class.

I would have expected that when the measurer originally measured this boat, if they had convcerns, they would relay it to the class administration and they would have decided if these boats were valid A classes.

A decision could be made at a later date to ban them.......

If you see an A-class sweeping by on the downwind in speeds around 15-20 knots and you see that the hull is lifted clear from the normal waterline due to the lift from the hydrofoils I would file a protest immediately. Since the hydrofoil is a grey zone and there are no ways no measure if a device is a hydrofoil or not this must probably be handled on water. There are no

rule

that bans the tips from the foils to be closer than 1.5 meters at the ISAF or A-cat website.

/hakan

Maybe it is just me but this rule is never going to work.

Afterall

hydrofoil

is nothing more then a

waterborn foil

as rudderboards and daggerboards are too. In effect a ruling this simple pretty much disallows all waterborne foils on the A-cat or is incapable of differentiating between traditional rudderboards/daggerboard and vertically lifting foils or parts thereof.

I never understood why this class voting in this rule as I never understood how it could be defended in a real protest for an independent jury (not containing any A-cat officials who thought up this rule)

Wouter

It has been a while since I've been witness to such a situation. ever since the introduction of asymmetric spinnakers on cats we've considered spinnakerless boats on downwind legs as stationary obstructions.

But I'll promise to look the next time an A sweeps by on the downwind leg, might take a while I'm afraid as I don't go over that often ! <img src=

alt=

/>

Wouter

Bill,

Why do hate the A-class so much ?

(The reply that was given the last time omeone made similar comments as you did here)

Wouter

I agree Wouter, the big problem is the rule that are very weak and that the next big A-class event is getting closer. Right now I guess that builders and those sailors that has the capability of building boats and foils are trying all kinds of curved foils using a rule that is very weak. This is going to be a disaster for the class unless the officials starts acting fast. And so far they have done NOTHING!!!

There could be a lot of protesting at the next worlds and in worst case a lot of DSQ. A boat could be measured ok but if it is sailed in such a way that it is

hydrofoiling

(whatever that means) then you could protest against it and get it out of the race or?

/hakan

Hakan,

Indeed, I don't envie the situation the A-class is in now. I'm sure it'll find a way out but some difficult times are ahead.

I'm not sure it will be a disaster, but I think we can expect the officials to be behind the curve on this one. I seem to recall that the same officials that came up with the

weak rule

are now the ones to correct the situation. In my life I haven't seen people cgo back on their initial opinion in a timely manner.

Personally, I think the partial lifting foils are an area that is perfect for the A's. It is in line with all developments that they have done in the past, like the carbon mast. As always I believe this to be the strong point of the A's. Especially now when they are no longer the fastest boat on the water or even the fastest singlehander. Two items they used to be in the past. As is commonly known, I truly believe that disaster is around the corner when tehe A's allow themselves to become a tightly regulated (concervatively designed) single sail singlehander. In that attire it will fall behind the other classes that WILL incorporate more and more upgrades like the carbon masts and lightweight construction over coming years. With each upgrade the A's will have less of an advantage and eventually just fall behind. The only way to stay out in front is to develop new stuff and progress the design. That has been the only reason the A's have stayed ahead of the fleet for so long as the 60's A's would have been overshadowed by other classes by the 80's if they hadn't evolved.

Personally, I think that fully lifting foils can be effectively banned, but partial foiling is impossible to ban without tightly regulating the daggerboard setup and limiting the boat to only one daggerboard set and a single rudderboard set. That will add alot of (detail) rules to the A-class rule set which is in direct conflict with the A-cat philosophy. So I think the way out it to go back a step remove to weak ruling altogether and introduce a single new rule that disallows full foiling (clear of water surface like the Moths). Then, let the development begin, with the A's having a new lease on life.

Wouter

I checked with Marstrom and right now ISAF have the

old rule

which stated that hydrofoils are not allowed and nothing more. But there are a new rule which states the tip distance and that the centerboard must be flush with the hull when fully rectracted. That means that you can get 0.4 m lifting surface from each centerboard and rudder and that could be enough to foil. The new rule was sent to ISAF yesterday!

Is would be interesting to know what rule that was in effect during the Europeans, the one at ISAF maybe?

If the statement

hydrofoils are nor allowed

is still there in the new rule you could still file a protest if someone is

flying

but otherwhise we have just made hydrofoiling a lot more expensive since we need to bypass the new rule.

/hakan

DOOM! IT'S ALL BOUND TO FAIL AND FULL OF DOOM!

geeesh...get a life.

Ground Hog Day

From a bunch of people that don't even own Ground Hogs no less.

Quote :This is going to be a disaster for the class unless the officials starts acting fast. And so far they have done NOTHING!!!

I am very close to the A-class official(s) and i can tell you that there is more debate going on then only on this forum .

Does any one know what the lifting difference is between a banana board, an angled straight board and a straight board in the vertical line with the boat. Calculated in theory.

Cheers,

Hans

Get an A-cat Jake instead of that old F18, then you might get a life <img src=

alt=

/>

Hi Hans,
good to hear that things are moving among the officials. Could you post the new rules here or give me a link to the rules. I could only find the old one on the A-cat and ISAF webpage.

I think you could get a lift of roughly 60 kg from a foil that is 0.4 m long and 0.3 meters in width in speeds of 15 knots. The foil is L-shaped in this example which means that only one edge has

end effect problems

of whatevere it is called.

/hakan

Hi Hakan,

I send you a mail.

Cheers,
Hans

Actually I do. I have a very well maintained Boyer Mk IV. <img src=

alt=

/>

Your signature still says F18. I know, sometimes it's hard to let go.

I thought they were a

fad

anyway.... <img src=

alt=

/>

doh....better now?

Wouter,
I like the Aclass, but the class keeps talking out both sides of their face - are they are developement class or not? They bill the class as a development class and thats whats gotten them this far, but tightening the ruleset goes against this philosophy.

I agree with your comments that the class need to continue to evolve in order to stay fresh and grow.

By the way, I'm on the Acat website, so I guess I'm not a hater.

http://bp0.blogger.com/_mLM5Q9YpULE/RwDy7AZKX7I/AAAAAAAAAA8/fV8EIv1SsoQ/s1600-h/Bill+Vinning.jpg