F16 AGM items for Zandvoort 2007

Hi everyone,
I'd like to get some discussion going about items to be included on the Agenda for the AGM to be held at the Global Challenge. All F16 owners are entitled to vote and a series of 3 ballots will be put to you shortly on some rule amendments/clarifications. Before any of you self-builders out there start to panic, there is nothing major in any of these proposals! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Discussion on the ballot items is welcomed here on Catsailor, but when it comes to the voting, it will be a simple agree/disagree option.

What I am looking for here is any additional agenda items that you might wish to be discussed at the AGM, considered by the F16GC, or put to a vote at the AGM.

In the case of a formal proposal, I will require a member to make the proposal and another member to second the motion. All items need to be submitted by 30th June so that the Agenda can be circulated prior to the AGM.

I look forward to hearing your views!

I would like to add the following items to the ballot / agenda

1, To ban the use of runnders that allow the "end tab" or "wings" trim to be altered while they remain in the "fully down" position.

This proposal is not to ban kick up rudders, but to ban variable trim T foil rudders. I believe that if we allow these type of T foil rudders we will instantly make all F16's currently sailing obsolete.

The reason I believe that these rudders would be so beneficial to performance are thus:

A, When sailing up wind it will be possible to trim the windward rudder to add righting moment by trimming the "end fin" so that the leaning edge is below the trailing edge and so the rudder will pull the windward hull down; By trimming the leeward rudder opposite i.e. with leading edge above the trailing edge on the fin you can create lift on the leeward hull. This will result in an appreciable addition in righting moment and thus speed.

B, when sailing down wind it will be possible to trim the rudders for the conditions - unlike the current T foils that can only be set once (for the day in theory by adding packers at the top or bottom of the rudders, but in practice only for trim of the boat as in order to change the trim of the end plates, you have to move the whole trim of the rudder). So in light winds the rudder fins would be trimmed flat so that no extra drag was given (over and above the actual drag of the T foil surfaces). When it is windy, the rudders can be trimmed to provide the right amount of "drag or pull" to hold the aft end of the boat flat. I could see that the primary trim for the hemlsman down wind COULD become the rudder fins if we allowed variable trim rudders.

You could then argue that we are a development class and as such should allow these are they are a development that boosts performance, however, I did some work on these before I got John to build my boat and they WOULD have made it much faster, but much more complex and expensive - I have ball park figures of 3000GBP for a working system based on the international Moth systems but with independant trim for each rudder (Moths only have one rudder).

I also believe that varible trim rudders will be difficult to build and thus make home build more difficult.

In summary I believe that variable trim rudders offer a large performance gain (at considerable cost) and so should be banned. If we do not ban them, the first boat to have them will make all current F16's obsolete.

Please can all people comment on this as I feel that it is critical that it is voted on as part of the 2007 ballot and banned at once.

2, Mast tip weight rule

I propose that the mast tip weight rule be removed from the class rules.

My reason for this is that it is already possible to build masts well below the tip weight rule, and this is limiting the minimum single handed crew weight as we have a class rule that states that the crew MUST be able to right the boat in all conditions - thus we have in effect put a minimum weight on a single hander because the mast tip weight rule directly controls the minum weight that can right the boat. I feel this is not a sensible control to have. We are basically saying that single handed sailors under a certain weight are not welcome in out freindly and growing class. I do not believe this is an appropiate rule to have.

2.1 I propose to simply remove the tip weight rule form the class rules, if people feel that this will be too much change too quickly and that mast designers need time to accomodate the rule change I would offer a second proposal thus:

2.2 I propose to reduce the tip weight by 1kg for the 2007 season (after the vote result) and then by a further 1kg the following year (2008) and then remove the tip weight rule from the class rules.


Please also comment on this too.

Cheers

Simon

Thank you for your comments Simon.

I have my views on these suggestions, of course, but don't know whether it would be possible for me to comment?

Any comments I make would be as an F16 owner and NOT as F16GC secretary. Would people object to me giving my views?

What I have seen people do in the past (and it seems effective) is have a login name for each role you can assume - an 'ordinary sailor' one and an 'official' one - e.g. jalani (unofficial/funny sig) and something like f16gcsec (official/boring sig). You can even disagree with youself then... which is not as daft as it sounds if you are forced to post an official view that you disagree with... <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" />

As you will have a vote on this (should it come to be voted on - do we have a method to ensure (given sufficient support from the members that an item WILL be voted on ?)) I don't see why you should not comment. I believe you would have to decide if your comments would influence others as they would feel that they could not be seend to go against a member of the F16GC.

I believe that we have an open exchange of views in the class and so would welcome your comments (and those of others on the F16GC).

Cheers

Simon

Duh! I never thought of that! Am I too dumb to be doing this job?

Thanks for the suggestion Colin. I'll get straight onto that <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

OK this is my new alter-ego!

I always firmly believed that a class official mus have the freedom to express his personal opinion if he so desires. I trust that the class officials are "professional" enough to not let personal views interfere with their official duties.

Hell, I've personally been accussed of many failings when I was an official but I never let my personal opinion affect my official duties, never. So it would be very childish of me to suspect the Governing Council to be any less dependable in this sense.

So I for one, will welcome your ideas and fully seperate the official statements from the personal ones.

Additionally, I can passionately disagree with somebody without disliking the person or not having respect for his official role. I think this F16 class has a high tolerance of this as well as many have learned to life with my diatripes ! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Wouter

John(F16Sec) / Scooby Simon,

One would assume there is a Class constitution.?

If so any proposed ammendments to the F16 class rules would need to follow certain guidelines before any proposal are accepted & then voted on.?

Marcus

This is the relevant section Marcus:

2.7 Amendments, changes, or additions

2.7.1 Any Formula 16 class member may propose amendments, additions or changes to the rule. They will be supported in their efforts by the Formula 16 authority with respect to communication and be given the means to propose the amendments, changes or additions to the class as a whole.

2.7.2 Only the Formula 16 authority may formalize amendments, additions and changes to the rule and will do so while consulting the class.

2.7.3 All amendments, changes or additions shall be placed on one pre-next-season notice unless the Formula 16 authoriy considers it to be essential to act immediately to prohibit or penalize a dangerous feature.

(I don't know if this is the best place to argue on proposals but until told otherwise...)

Are you proposing a ban on actuating control surfaces on the rudder or more generally all T-foil rudders?

What's your definition of "variable trim"?

I think banning packing of the rudder pintles on the transom is going to be impossible to police.

There are so many possible solutions for changing the lift characteristics of a T-foil on a rudder that your proposal needs to be refined a bit.

That cost of an actuating t-foil system seems a little extreme. The solution that the bladeriders are now incorporating, which many moths are now following, is very simple. The parts that make hydrofoils expensive are the actual foils, the actuating mechanism is a small percentage of that. It isn't that difficult for an amateur to build one with a little education.

There are three options:
- Ban T-foils outright. (Simple)
- Allow any arrangement or configuration of T-foils. (Simple)
- Have a compromise between the two. (Opening up a huge can of worms)

My personal preference is for allowing them with any configuration. Everyone is becoming convinced that they are better. The International 14 is booming since they introduced them, mainly because they are apparently much easier to sail than without them.

Second preference is for fixed blades that only actuate about a vertical axis while sailing (ie. a standard rudder with the option of a horizontal foil solidly fixed to it)

Argument against banning T-foils is that they will be something that will distinguish the class from F18's. To new sailors, F16's and F18's look very similar. Basic marketing strategy involves distinguishing yourself from the competition, whether actually or just in appearance. It's not a big difference when sailing because you won't regularly see them, but on land they will draw attention.

I don't like the current rule about mast tip weight either, but I do like having a structural check on these relatively flimsy masts...I'm assuming that's the reason it was introduced.

I don't think there is any other way to have the best of both worlds for this one. Unrestrict the mast weight and the fear is that there will be numerous lightweight expensive carbon masts built, then broken. Have the tornados gone to carbon masts?

I'd just like to also point out that your two proposals have one argument in common, cost, except that for one proposal it is used as a negative in the argument (T-foils) and for the other it is ignored (Masts)! Cost is a negative of both proposals, few ppl would want to buy an extra mast sometime in the future because the rules changed.

Anyway, these are just my opinions. I guess we'll see what is proposed for the vote.

I wouldn't want to see T-foil rudders banned but I can see that being able to adjust those foils while sailing could have tremendous advantages. We have always declared that we wouldn't want to become an 'arms race' class and therefore rules need to be deisgned so that costs of boats (both capital and running costs) can be kept under control. Coupled with this is the desire to keep older boats competitive for longer than many other classes.

£3000 seems inordinately high for adjustable rudders, but I haven't investigated costs so I'll accept your point Scooby. However, the question then is could this be done cheaper and can it be retro-fitted to older boats? My guess is the answer to both is 'Yes'.

Should we be inhibiting development in a development class? - that's a difficult one. In the best interests of the class we DO need to control developments. It may be that initially we need to ban a particular development and then permit it a few years later (perhaps once relevant technology becomes cheaper) but I am reluctant to ban on a perceived threat - particularly in respect of something like rudders that, after all, just hang on the back of the boat and could therefore be changed on any boat.

Personally, I'd like to know a bit more about the cons of having adjustable T-foils before I'd vote for a ban. I like to keep an open mind to developments, but if the cost of a new idea is shown to be out of reach of most people I'd vote for a ban in an instant.

On the mast tip weight rule - I've never liked this rule and with the speed at which mast technology is developing I think it to be an unnecessary hinderance to better masts and for a lightweight like me I'd love to have a lighter, more flexible mast. Having said that, I don't believe we could just remove the rule in one go. Nor do I think that 2 years is enough. If it were to be slated for removal then I think it should be removed over 4 or 6 years.

I've never been a fan of the mast tip weight rule either. I've always felt that the issue of structural integrity is between the sailor, the builder and the warranty. I wouldn't buy a boat that I felt had a mast that wasn't up to the job.

I'm also not overly concerned about how quickly the rule is introduced. I sail with an alu mast, which I assume is way over the current mast tip limit, and I don't find it puts me at a significant disadvantage against the Stealths, which presumably are a lot closer.

What would you expect manufacturers to do during the transition period? Put some kind of removable weight at the top of the mast? Or build boats that are "obsoleted" within a year or two? (Although as per my previous point, this obsoletion will be more buyers' perception than anything else)

Paul

I think that a weight at the top of the mast is the obvious solution. When the Tornados went through a spate of new mast designs in the early 80's I ended op with 0.25Kg of lead screwed to the top of my new slim taper Sailspar mast.

If we go down this path then people can build the mast as light as they dare, add the appropriate tip weight for the year or two then reduce it over time. They will always have a mast that is 'down to minimum'.

The reason for suggesting that change like this should be spread over a longish period is so that people have the opportunity to do just what I have outlined above. If a heavier mast remains unbent or unbroken during that period then it is up to the individual to either keep it or replace it with a new lightweight one and use it as a spare.

Gero,
The mast tip rule was introduced to minimise the perceived performance difference between carbon and aluminium masts.
Removal or even further reduction of the weight means you are affectively forcing the class to be compelled to use the more expensive carbon masts. If you think I'm wrong, ask yourself how many top A classes are sailing around with aluminium masts.

As far as adjustable T foils.
I designed some adjustable T foils a year or so back and the cost difference is not significant. Closer to 300 rather than 3000.
You can retrofit a system to existing foils. No big deal.

Regards,
Phill

I would like to ban the ability to trim the "end fences" or "T foil INDEPENDANT" of the blade while sailing.

The big cost in this is the development of a double twist grip (or other method) to allow you to trim each T foil independantly; The 3K GBP is an approximation based on the 2K to convert a standard Moth to dual foil (moths have foils on the plate and rudder; the plate foil is controlled via a prodder in front of the boat and is fairly simple. The rudder control is changeable manually and is the complex part. I believe a "independant rudder" control for a catamaran will be complex and expensive to make and provide an immence advantage once done.

I do not want to ban the current T foils as I firmly believe they offer an andvantage at limited cost or handling penality, I also do not want to bad the adding of packing behind the rudders in order to trim them correctly. It would be impossible to control and someone has to make another boat trim decision before starting the race (just as setting the rig tension which is currently in the class rules).

The proposal is to solely ban a development that will be

a, Costly
b, If allowed make all current F16 designs obsolete and require all current boats to adopt this at significant cost.




Regarding the mast tip weight rule, I don't believe removing the rule will make a SIGNIFICANT difference - it will not make boats obsolete overnight, but the rule does limit who can sail the boat. We have a rule that by measuring the tip weight, we limit who can sail the boat single handed.

Phil, were these adjustable from the wire so you can trim one positive and one negitive at the same time ?

What is the difference in cost between a carbon and alu mast? Is it that much? The only production F16 currently being offered with a carbon mast (as far as I'm aware) is the Stealth, and that doesn't seem to come out any more expensive as a result.

Paul

Paul,

The Blade is also available with a carbon mast.

Regards,
Hans

Hans,

What is the cost difference?

Paul,
If you look at the difference between an aluminium wing mast and a carbon wing mast blank section I'd expect you are looking at well in excess of $2000.

Regards,
Phill

Is this mast the exactly the same section as the Alu mast ?

I think for this kind of debate people must try and compare oranges with oranges.

There is no point trying to compare masts of different construction if they do not have the same section - I admit that the carbon and Alu masts will certainly have different bend and so are not totally the same if they have the same section.

Hi all,

my personal opinion for what it is worth.

T foils adjustability should be banned.

Why? I like sailing the boat not making adjustments and don't want to add any extra costs. Also two up boats would have an extra advantage as one ups already have too much to do.

Mast tip weight, should be kept.

Why? It keeps Aluminium Masts close to Carbon in weight reducing performance advantage. In OZ Carbon masts are far more expensive than Aluminium masts as the only moulds are for A class style wing masts, which cost aprox. double. Also has proven to be strong enough, but not heavy by other cat standards except A's.

In closing, we have to keep costs under control and realize, that people the world over have different access to materials, equipment and ability to pay for or build it themselves. I have met I14 sailors in OZ that have got out of the class because of expense of all carbon rigs and adjustable foils.

Doesn't hurt to discuss things though, keep it coming <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />.

I think that's a very compelling argument, especially as the biggest gains come in high winds, where the 2-up boats are already have the edge.

Paul

Hi Simon,

the Alloy Superwing mast and Carbon A masts are as similar in section as a Alloy mast can get to a carbon wing. That is the only comparison we have in OZ. Even a second hand A class carbon mast costs about the same as a new Alloy Superwing. I have been looking at this for a while, I was just lucky that the old A I bought and "Altered" to a F16 had a carbon mast with it, which after strenghthening which brought it up to weight was strong enough.

The other thing we want to avoid is what the Taipan Class used to have, which was cat rig and sloop rig masts of different strength and weight, because over time boats where bought and sold, changed from one up to two up and broke masts which wasn't good for the class. They now only make one weight of Superwing strong enough for Two Up. <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

Finaly with no minimum weight people could put A class masts on F16, without strengthening some would certainly not be strong enough, they break on A classes <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />.

I think the added complexity of adjustable foils, especially individually, dont neccesarily pay off largely. But I am more inclined to not disallow what hasn't been built and tested yet. Performance data both on this and banana boards (which are already disallowed) are not clear, so why ban them? Perhaps someone shows up at Zandvoort with something experimental and sweep the fleet, but I think the risk for that is relatively small. The odds of getting it wrong or breaking the stuff is probably larger. If the technology shows itself to either add too much complexity, fragility or cost, then ban it.

Mast tip weight should in my opinion still be there. Carbon is still expensive, while there are lots of alu masts/sections available. I wonder how much the corrector weights on the carbon masts mean for crew weight range on the boats? Are we talking1.5kgs or 15kgs wider weight range?

Rolf, but if we ban them once someone has spent (a lot) of money on developing them they will not be happy; if we just ban them then the problem goes away.

I firmly believe they will give a considerable andvantage upwind as you can create RM and a massive advantage downwind as you can wind on the anti-pitchpole when you need it. I just feel they are an expensive and complex system that will give gains and if we don't ban them we will be sailing obsolete boats. I do not believe that the tip weight on the mast difference is so great.

Scooby,
Not exact same but very similar.
Exact same would most likely have a greater cost differential.

As far as adjustable T foils. The design I was working on was not for an F16 but could be used on one. I currently have no intention of doing this.

The point is if we ban adjustable foils but reduce the tip weight to make carbon mast almost compulsorary what have we achieved.
One rule change may limit "possible" costs in the future while the other will make sure we have additional costs now.
From someone who has been here from the beginning, we've been through this too many times already.

Simon, I dont agree. As long as the ones who develop these rudders are in touch with the community, they will know the rudders will be banned unless they are cheap, easy to use and affordable. If they dont stay in touch, they know they are taking a risk.
On the other hand, if they come up with a good and affordable solution that proves effective, why ban it? More power and speed to the F16 is good.

I feel as the governing body we have to examine closely changes to ensure that they help continue to grow the class and not hinder it, no matter our personal opinions about what may be "better" or cool for the boat. We are a development class but in the extreme we can easily go the way of the C or the F18 depending on some of these choices.

1) Tip weight - As Phill pointed out, if we remove the tip weight rule the apparent advantage is goint o fall to the Carbon masts. This is significantly more expensive and potentially more fragile than the aluminum sections. The cost to advantage gain, I do not feel is worth it and the current cost of these platforms is at the high end of what most people ar willing to spend. We are not a class with a huge base and providing any boats with a percieved advantage will only help obsolete the others in the eye of the buyers and help to alienate people who are already in the class.

2) Adjustable foils - Same for this. Added cost to the boats and the poetentail to create an impression that it is a must have feature.

Personally I do not like the tip weight and feel that if you want to add complexity to your rig with adjustable foils, good luck, it is hard enough to keep the boat going the right way fast without having a couple more things to adjust that could easily be providing as much of a detriment as a gain. However, The F16 concept is perfect for me and I want to see that the class keeps growing. More and better sailors continue to come in and a used boat market develop sto help expand the base. Do anything to make it more complex or expensive is a detriment to this growth and something I feel should be carefully avoided.

Matt

[quote. . . Do anything to make it more complex or expensive is a detriment to this growth and something I feel should be carefully avoided.

Matt [/quote]

Well said! Couldn't agree more!

Well said! Couldn't agree more! [/quote]


I also agree.

Regards,
Phill

But how do you define cheap ?

Someone earning 200,000GBP PA would not flinch at spending 3K (or more) on Variable trim T foils that give a significant advantage; someone who is a student or earning a more "normal" wage would probably balk at spending this money. I am afraid that "cheap" is just a variable based on personal circumstances.

If we ban them, the problem goes away and we control one item in the potential arms race.



Tip weight I agree is more of an issue; however Somone commented that Carbon masts may be more fragile. I'd disagree with this; I took far more "care" with my old heavy Inter 17 Alu mast than I do with my Stealth Carbon one; both about the same length and the F16 one is far lighter. I believe that carbon masts are far stronger, but can be made more precisly and so we should vote on both these items. I've seen may more broken Alu masts when dailing with Kites than carbon ones. I also feel that Carbon masts would only loose a cpouple more KG and stay strong enough - note that the carbon (A class mast) on Altered was strenghtend to cvope with the rigors of F16 sailing.

The same argument can be made about carbon masts.
I don't like the tip rule but it is good for the class.
It's not like we have not voted on this before.

Since then carbon and labour (the major cost) have gone up- so it is unlikely the price of the masts has come down.

Regards,
Phill

Selfishly!

I don't want to spend any more than is necessary. I'm COMPLETELY satisfied with the performance I now have. I'm unwilling to pay anymore for a competitve boat.

I'm unconvinced carbon is better for masts.

We are already having enough growth problems without increasing the price of the boat and equipment.

Cheap? My definition is like yours, something I could easily afford without my wife discovering it. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
I do not have extra money to spend, but I dont want to stiffle innovation either. Neither do I see a reason to ban something which is not a problem yet. I think there will be huge problems in using these individually adjustable T-foils and they are probably not faster around the bouyos than a well sailed regular equipped boat due to handling issues. I think it will take more than a Rohan Veal to make these things work, so why ban them now instead of watching an potential development carefully?


Phill,

the masts we have gotten for our F16 project are tapered sections. Alu Tornado rigs are so cheap these days you literally get them thrown after you.

Carbon masts already have an advantage due to their customized stiffness (if you pay for it of course). Removing the tip weight will tip the scales for the carbon masts if you want to be really competitive. After the switch to SMOD carbon masts in the Tornado class none who want to be competitive use alu masts, even if they are faster in certain conditions and as fast mostly. I would like to say more on the topic, but I am off to celebrate our norwegian independence day <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Rolf,

the issue is that there are very considerable benefits to variable trim rudders that WILL make the boats obsolete once someone gets them to work - if we allow someone to develop them we cannot then just ban them. This is the crux of the issue - we either allow them and wait for someone to devlop them (and thus make our boats obsolete). Or we ban them now.

The class will look very ver ystupid if we do not ban something, then allow someone to develop itand then ban it

This would not be a sensible option IMO.

I am against banning adjustable T foils. Anything that might be a development should be encouraged and we should not restict ourselves.

However I think the thinking about adjustable T foils is flawed. A foiling moth is a foiling boat. An F16 is not a foiler. We adjust the balance of the boat by trim and weightshifting. If we get this out of balance then the T foil angle of attack will help correct it e.g. preventing a pitchpole. If the wind and weight balance is suddenly altered, the T foil angle of attack changes and helps correct the balance. We have a 16 foot waterline to balance. A foiling boat only has about 6 inches water line and the foil angle of attack is far more critical. Since every action need an equal and opposite one, by adjusting the T foils to balance a catamaran will be countered by changing the weight shift or trim. This means that if a T foil angle of attack needs to be changed then the boat must be sailing out of balance. In the current configuration on the Stealth, the T Foils are most active when either overpowered down wind or when the boat has to react to a gust. The foils correct the temporary out of balance boat. To use one as a continuous balnce control would only slow the boat down. A T foil does not generate energy.

The Hobie Tri foiler sails better than a Rave because the sensors anticipate the waves and the foil angle of attack changes before the wave hits it. A trailing edge elevator cannot do this. I think the foiling moths have been trying this idea out as well. This will not apply to our displacement 16 foot hulls.

I may be wrong but the only way to prove it is to develop it. So don't let's ban it.

I would like to comment on Carbon masts on F16s, I need to start by saying that I have a personal interest in carbon masts as I build them for F16's.

Firstly the debate should only be about the pros and cons for losing the tip weight, not about the durability or competitiveness of the 2 materials.

Argueing that we must have a weight to guarrantee durabilty is silly since no other part of the boat is governed in this way.

Sure someone could put an A mast on that is too weak, but they could put an aluminium one on that is too weak, or a wooden one, or they could build the hulls in paper. Our rules don't limit materials so why should we specify how much material is used for individual components.

The fact is that a very durable carbon mast (stronger than current alumium ones) can be built with a tip weight under 5kgs, and this is likely to come down with time. Adding 1.5 kgs to the top of a mast requires an extra 12 kgs or 24lbs of body mass to right the boat.

So what are the pros and cons for removing tip weights.

Cons

The only con is the percieved competitive equaility of bolting the lead to the top of the mast, but 90% of the advantage of a carbon masts comes from the abilty to develope a bend characteristic to suit the boat and the crew weight. So there is only a small speed hit to the carbon mast with 1.5kgs of lead on the top, and this is only in choppy conditions upwind.

Pros

Again only 1 in my opinion, and that is righting the boat, I know that many of my customers bought F16s because they are easy to right single handed, some sold FX1s and inter 17s for this reason and no other. Make no mistake for a lot of people this is important, in almost every demo I have done for a single handed sailor, he has insisted on capsizing and righting the boat on his own.

Does bolting 1.5 kgs of lead to the top a mast slow the boat down? not so that you would ever notice, but if you weigh 70 kgs it makes it bloody hard to get the boat up after you fall in the sea.

If the tip weight rule is nixed then people with money will go carbon and whether you can utilize the unique aspects of carbon to make your boat faster is almost besides the point. Would anyone buy a new A cat these days with an aluminum mast?
From a basic point of view - Getting a carbon mast is something like a 3000USD option... maybe it is different elsewhere and I sure you could find an older mast that would work BUT I think it would outprice a not so insignificant percentage of possible buyers.
BTW... I love the carbon mast on the Jav2 18HT. It is one reason why the boat works so well and I also think it is more durable than any other mast I have seen.

Whether or not you can utilise the advantage IS the whole point, and you can utilise 90% of it even with the tip rule in.

Are you saying that if carbon masts are allowed everyone will want them?

And a carbon tube will cost you around $2000 so when you you take off the price of the aluminium tube it's about $1500 difference

Carbon is allowed now obviously, but the tip weight rule makes the cost/benefit ratio go up. I did some small research and was told that a carbon mast adds about 3000 to the price of a blade. This is not specific but knowing a local carbon expert I think this is about accurate.
What do you think would happen to the F18 class if carbon were allowed? Every boat produced from here on would have a carbon mast. It would fragment the class (but it would likely recover but maybe it should fragment it and hopefully kill the need for 400lb boats <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> )
In truth I am not sure- and no one really can be- but I think if the tip rule is dropped carbon would become the "standard" and the price of the boats will go up 2k at least. If everyone is cool with that and think it will still allow the class to grow (and it certainly has a lot of allure even adding the 2k) then do it. I can afford the extra 2-3k but it would irk me to think that I am trying to buy some advantage at the expense of people trying to get into the class. Newbies would look at it and want a carbon mast for sure because carbon is absolutely cool. Aluminum is so "old school!" <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I have broken a Hobie 16 ali mast a Hurricane ali mast and I have broken a Stealth F16 carbon mast. The cost to replace each mast was the same. I dont understand the argument that cost is the factor. How much is an F16 ali mast? Can someone tell me? We might be surpised. It might cost more than a carbon one!

Where do you guys live that carbon is so "cheap?"

Any US guys want to back me up or shoot me down?

If carbon costs the same as aluminum then absolutely get rid of the tip weight rule.. without a doubt. I think if the costs were the same we wouldn't be having this discussion

Maybe Alu is more expensive in parts of the world.

good point.. didn't think the other way around <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Ali has certainly gone up in price in the last 12-18 months. Just talk to anyone involved in marine insurance and they'll confirm that thefts of spars from dinghy parks have gone ballistic. The spars are then sold on as scrap <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />

No-one seems to be stealing carbon spars though <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

I have to agree with David, a bare carbon mast compared to ali is not much more expensive, its the fittings and build time which racks up the costs and that is equal what ever mast you use. Dare i say it but I think a few of the Carbon mast manufacturers do rely in the mystique of Carbon to justify their prices.

We are a unique class in that we are in essense an experimental class, now everybody acknowledges that carbon masts are better so why are we dithering, lets bite the bullet and allow any mast you like as long as its class legal in girth and length. As a by product of that move you will allow light weights to sail solo, have less masts break and be seen to be a modern look ahead class.

Scooby Simon your perceived thoughts on just how effective adjustable T Foils could be is way over the top, if you are so worried about them then simply put an overall area size for the horizontal foil, if the area is small enough then no matter how much angle of attack they have, they simply cannot generate enough lift to be able to influence a 16ft boat.

David is very right in saying that the foils we use are completely different to that of the Moths, our small foils will never create enough lift unlike the Moths which are quite large and designed for lifting the whole hull out of the water <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

So......

Perhaps we need to just discuss the rules and not the construction of the masts...


I relly feel we should make the tip weight rule the subject of a formal poll for Zandvoort.

If you relly(sic) feel that scooby, then draft a proposal and submit it with another member to second it and the F16GC are duty bound to put it to the members. BUT I recommend that you think very carefully about the wording as, if passed, it will become part of the F16 ruleset and will need to be robust enough to stand up to people trying to circumvent it if they can (although in a simple case of removing an existing rule I guess that's not a concern).

OK.

Would someone be willing to support this :

Remove rule 1.4.5 from the class rules for the F16 Catamaran. The rule currently reads:



Proposal to go the the F16GC.

Proposal "Remove rule 1.4.5 from the F16 box rule".

Wayne,

I am not trying to ban the foils as I believe they can lift the boat out of the water ! the exact opposite. I believe with trimming the foils upwind you can created righting moment and thus drastically improve the upwind performance; I also believe that you can then also trimm them to create the extra drag to make pitchpoles almost impossible.

In Australia an aluminium wing mast blank cost $990,
while a carbon wing mast blank cost $3000 to $4000.

It has been stated the difference in the USA is similar at $3000.

These are substantial increases in costs to people you are trying to lure into the class.
Good luck to the UK guys if they don't have such a large price differential.

Until the cost is similar on a global basis changing the rule is very much to the detriment of the class and will kill the potential growth in many countries.

First, we dont know the benefits yet as there are no boats equipped with these rudders (which is what I want to see before an eventual ban is introduced).
It might be that I am just too simple to understand so you have to feed it to me with teaspoons, but why would the class look stupid if we didnt ban such rudders before someone developed the technology and skills necessary to make them work?
I prefer rulesets to be "reactive" and based on what we know, not "proactive" based on what we assume. Especially so in a formula ruleset where there is supposed to be room for experimentation and development.
This whole matter just might be a lot of hot air as trimming two independent T-foils from the trapeze seems a daunting task to me. We are obviously not going to agree on this matter, but I would like to understand why banning new technology before it has been tested and tried is so vital?

People are using the cost item to disallow my proposal on tip weight and so I use the same argument to counter this one. When someone gets it working there will be massive benefits and it will be very costly. When this is working I don't believe a non varible trim boat will be able to compete; it will mean that we MUST all make our boats work with variable trim rudders.

Simple as that.

Rolf, how about you support me on proposing this ban (and then vote against it) so we can see what the F16 community really think ? I am simply proposing this ban to control costs on a solution I believe firmly would mean we all would HAVE TO follow it to stay even remotly in touch.

To make the foils work well enough to prevent a pitch pole is a big ask, there is a huge leverage effect of the Spinnaker on the mast sufficient for me to think ( without a clear calculation ) that any wing able to prevent this would also be creating a huge amount of drag thus slowing the boat to such a point that any gain would be nullified.

I agree with Rolf, we should be promoting a bit of experimentation and trial and see, if adjustiable T Foils did have such gains then so be it, think of it as a safety aid ( pitchpoles are pretty scary things ) but I still very much doubt it. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

You are not playing at politics, are you <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Cost control is vital, hence my stand on carbon masts. But then carbon masts is a relatively well known technology. Adjustable T-foil rudders as seen on the I-14's and foiling Moth's are still relatively new technology with complex solutions. I can't even imagine what the control system for two controllable T-foil rudders would look like.. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
I am relatively relaxed on the matter, even if I keep on with my line of arguments, as I think this will be too complex for use.
If a working prototype came along and was clearly superior around the course, but at a cost above GBP£450, I would be among the first in the line of sailors pouring concrete into the bucket for their feet. That is, unless there was an option of homebuilding the same system at a reasonable cost. There is probably not a lot more to say about topic..
What I really dont like is suggestions about limiting the size of T-foils, again based on the fact that we dont know much about them.

Sorry, but I dont think my vote will be accepted. I only have a collection of parts for a boat yet, not a boat. We are going to strip plank the hulls, and the drawings for the stations have not been done yet. Got a sailnumber tough, NOR-25, and the budget is so small that it has slipped under the radar of my wife.

I you paid for a set of plans, that's good enough for me.

I'm not playing politics at all; I just want this properly discussed and a vote taken and a decision made. I firmly believe that if we allow it, it will work and it will be expensive.

I'm not willing myself to spend the time in making it work with the possibility of it then being banned, but if someone does I (and I firmly believe all others) have to go to this.

Question for John and Hans; If a boat was made to work, could it be retrospectivly banned ?

I think a lot of the discussion is mirroring what has previously happened in the moths, it's actually quite interesting how similar the topics and their arguments for and against are!!!

The very first foiling moth and its cousin were retrospectively banned. The builder then went on to develop the next generation foiler that you see today. Very sucessful transition don't you think.

A carbon moth mast costs less than an aluminium moth mast, I should know, I got the quotes! Admittedly one of the technologies to build carbon moth masts (filament winding) is now very mature, hence very cheap, so the other methods are forced to come down to a reasonable price.

Moths were using fixed T-foil rudders for years very successfully. There was a transition period of a few years, while the foilers were developing, where manually actuated rudder T-foils were popular and sometimes complicated. The system now is such that there is almost no actuating of the rudder T-foil while racing, and the systems that are used are again, very mature and not very complicated. Applying them to a twin rudder system is another matter though.

Carbon masts are already allowed in the rules, the weight restriction sort of dampens their main benefit though, that of reducing weight. But the other benefits are still there, increased stiffness, customisation to a crew weight, etc...I don't think deleting the weight restriction is going to help the class as a whole. Someone who wants a carbon mast can already buy or build a carbon mast and have most of the benefits associated with carbon masts. They are not necessarily expensive or hard to build, they just require a bit of thought.

If you propose a rudder T-foil rule amendment, make sure you get it right. I wouldn't want to see a complete banning of T-foils, nor a poorly thought out or worded compromise that allows some systems but has unexpected implications.

My current stance is:
- Leave the mast tip weight rule as is.
- Leave the T-foil development alone for a while longer to see what emerges.

If the T-foil debate becomes an issue, the class is allowed to vote on it in the future and any builder/buyer just needs to take that risk if they want to. The discussion here and on the rigging lawn should give builders a good indication of whether it is wanted or not.

I for one will be attaching fixed T-foils to the bottom of my rudders eventually (probably a year or two away yet), and probably pack the rudder pintles as desired for the conditions. There may be some sort of system to change the angle on the water but only between races, something like racing car spoiler adjustments in pit-stop.

The whole point of using T foils on a cat (two, one on each rudder) is to greatly reduce pitching, which is exactly what they do whether fixed or adjustable. Who the hell would want to have to adjust T foils on a cat when fixed foils work so well anyway, and, for a cat, it is very dubious whether having adjustable foils could even be used IN ACTUAL PRACTICE on the water to advantage. It is easy to sit back and debate all sorts of scenarios about “if you did this” and “if you did that” and argue endlessly about some conceived resulting advantage – THEN THROW OUT THE BABY WITH THE BATH WATER – Why don’t you at least wait until some one actually tries before you decide. Banning adjustable T foils when non really exist for cats is the same as convicting some one of a heinous crime in their absence (and later finding out you were in error)
I have tried and found that for me adjustable foils were an abomination on a cat (Good for two handed mono hulls that by our standards are slow and allow “time” though) and there is no need to ban them as I don’t think anyone will ever come up with a system of adjustable T foils for a cat that will ever be used.
I call this whole debate nothing more than a “storm in a teacup”
Mast tip weight though is something else – I think it should be removed – I feel strongly that it is something that will, in the future restrict the class rather than what it’s intended intention now is. I put it in the category of there being certain dimensions that are necessary to define the object, but too many “restriction” are never good (particularly in the long term) Good forward thinking is what makes the difference between long life and a seven day wonder and I don’t really think “mast tip” is long term thinking but more like an unnecessary restriction that may come back to bite you on the bum.

against banning adjustable foils..

Had some experience with the adjustable I14 foils.. We made ours very cheaply.. So money isnt an issue..

As for tweeking and gaining advantage we could use this argument with downhalls, outhauls cunnighams ect..

one can do this by weight distribution.. proposing to ban this as well?

I beleive all this debate is great,if you ban tip weight it will automatically start the have and the have not divisions same result wiil be if T foils are introduced.
I beleive alluminium masts where used to keeps costs down and also durability ,maybe carbon has come a long way from the early days .
As for splintering a class you guys/gals are standing on the edge of a slope with a lot of other guys/gals standing behind watching what is about to happen because if the class starts bringing in changes that will increase costs on boats and maybe repair issues they might go else where or stay where they are, because 1 in all in (take the A class for example)
anyway thats my view from someone standing behind

[color:"blue"] Simon,

I think the answer to your question on retrospective banning of a development can be found here: [/color]

2.6 Spirit of the Rule

2.6.1 In case of doubt, the intention of the rule makers, which is the spirit, shall
take precedence over the letter of the rule.

2.6.2 The spirit of the rule includes, among other principles, the following considerations :

2.6.2.A Preserving general equality in overall performance between craft of different make, accepting small variations, in order to guarantee fair racing between designs of different make.

2.6.2.B Maximizing the freedom to optimize a design to personal preference and to improve the performance of a given crew and craft through refinement.

2.6.2.C The allowance to gently improve, by design, the handling and overal behaviour of a craft in small controlled steps which don't upset the balance in the class to the extent that the continued existence and growth of the class are no longer guaranteed.

[color:"blue"] or: [/color]

2.7.3 All amendments, changes or additions shall be placed on one pre-next-season notice unless the Formula 16 authoriy considers it to be essential to act immediately to prohibit or penalize a dangerous feature.

[color:"blue"] So the answer is Yes, such a development could well be banned retrospectively. [/color]

The cost of an Alu mast per mast is surprising low. The only real drawback of alu mast production is the fact you have to run a batch of them, typically 250 kg or 500 kg per production run.

I may not disclose the real production cost of an Alu mast section, I can tell you however that John Pierce earlier statement about the price difference is quite close.

For that price difference we can even have a new die build for each batch of 17 to 34 masts, which will improve accuracy and even allow the masts to be redesigned with each batch if progressing experiences demands that.

This is just to answer Davids questions and this is not an argment in voting for or against the proposed changes.

Wouter

This is not my experience and I've been involved in some actual F16 alu beam production and the designing of a new Alu F16 mast.

Additionally theft is theft and this doesn't factor in into the new price of a commercially build boat.

Wouter

Although a system for a cat is going to be a bit more complex, especially if it is to do what Simon suggests and control the blades in opposite directions upwind and in the same direction downwind.

Paul

Would a nice compromise not be to rule that it may not be possible that the angle of the T-foils relative to the hulls is adjusted while racing ?

Thus allowing adjustment between races and still leave the room for experimentation open without the fear of rising costs as there is no need for expensive control system when you can't adjust them while racing (sailing).

This is also the way we adressed the fears that were around a while back about systems that could rerake or heel the rig towards the wind while sailing/racing. Now people have only staymasters on their boats so they can adjust the trim in the break between races but not during races. This has proven to allow maximal adjustment of trim without adding any real costs.

Wouter

Ncik,

You moth example is an excellent one.

The Moths spent considerable time and money developing their system and very good it it too. It's also not Cheap.

As this development was going on, the 3 moth sailors I know all said "I'll never go foiling, I cannot afford it". 18 months later they were foiling as "I had no choice, the class was going that way and the non foiling boats were dieing". I consider this is the risk we take with the F16 class - we may end up with 2 types of F16; those that use variable trimm and those that do not.

The are now very few foiling Moths sailing sailing in events and they are NOT competitive in wind over 7 kts This may happen to the F16 class.

As John says, the F16GC could ban these boats retrospectively. Do we want to do this ?

From what I can gather, if a vote was taken to ban variable trim rudders it would probably not pass. The class as a whole needs to understand the implications of this. People who way "lets see what happen" I can understand, I am just wanting people to understand the potential for this system.

(I have one designed that would be automatic for sailing up wind and require "setting once" for a downwind leg). If I win the lottery I would develop this. I believe that the possible banning under the "spirit of the rule" gives the class a "get-out-of-jail" free card that may well prevent anyone taking the risk.)


People above have expressed worries about who we could attract to the class with the proposed change to the tip weight rule. We are activly PREVENTING people from taking part as they cannot right the boat single handed.

I would second Simon's proposal that the minimum mast tip weight be abolished. This has to be the safest option for the sailors.

Hi Simon,

you say we are stopping lightweights from sailing F16, as they can't right them due to the mast tip being to heavy. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

What cat can they right? The A would be the only one lighter and with it's mast 1/2 a metre taller all you need is some water on top of the sail or dacron soaking up water and the difference is minimal. How attractive to these jockey's is a class with a larger main than a A class and a 17m2 Spinnaker to boot.

Sorry but I think this argument is a Furfey. Besides the tip weight rule is one of the newest for the class, it was reduced not long ago and if I recall correctly the class did not want to drop the tip weight rule then.

The F16 has a class rule that the crew must be able to right the boat in ALL conditions. I am not sure other classes have this rule. This means that someone who is fairly light (maybe below 70kg) would not be able to right the boat in ZERO WIND.

Thank you to all who are contributing to this thread. Despite the reservations shown by some before I asked for agenda items, this thread has, on the whole, been very civilised. Valid points have been raised by a number of members and reasoned arguments have been presented.

I do need to make it clear however, that this thread is asking for items to be placed before the members AT THE AGM. As such, the AGM will be presented only with those items that have been formally proposed by 30th June plus the results of the 3 existing ballots.

If we are to follow the requirements of the constitution, we have insufficient time for any formal proposals arising out of this thread to be balloted BEFORE the AGM. Therefore ballots on any agenda items will have to take place after the AGM, perhaps during 2008 or maybe just before the 2008 AGM. After all the 3 ballot items that we have at present have been 'in the works' for almost 8 months as it is!

There is one particular point that also needs to be made and that is that the introduction of any amendment will be to a timetable set by the F16GC and we will act only in the best interests of the class - particularly bearing in mind the rule section on 'the spirit of the rule'. Stability of growth of the Formula 16 Class is our aim above all else.

Therefore any fears that anyone may be having that their boat is suddenly going to be out of class/ uncompetitive /devalued are, I believe, groundless.

Whoa Whoa whoa, one thing you forget to mention is that the moths were experiencing a significant downturn in participation before foiling techology was developed! Now they've got many companies around the world (some very large ones too) not able to build them fast enough to keep up with demand!!! Moths are experiencing a world wide resurgence since they introduced foils!!! So how can you say that foiling has hurt the class!!!

There was also a discussion about banning controllable surfaces on the foilers early in their development. The top guys just said, "ok, we'll learn to sail them no matter what the rules...control surfaces or not..."

Admittedly the marketing of moths has helped this resurgence.

Don't fear the technology. We'd still be in the dark ages if we feared technology.

You wouldn't be banning the boats retrospectively, just the components!

Whether adjustable T foils are banned or are not banned really makes no difference in the long term, they are just not going to be able to be used to gain any advantage over non adjustable ones on any OTB catamarans, I would cover any amount of money that any one is prepared to bet that this proves to be the case.
So why ban something that is so improbable as to be an absolute "non event"?
If some one came up with a “silly” proposal that a gaff rigged sail was faster would anyone even consider incorporating it as a restricted option for the class? Of course not, something’s are just so self evident that they do not need enunciating (or incorporating in writing as in this case) Take a good look guys adjustable T foils are just not going to happen on cats (not without hydrofoils to the bottom of CB/ dagger boards any way)
Careful guys, the more restriction that are added move the “class” closer and closer to a “one design class” and that is definitely outside “the spirit of the class”. It is either development or it is one design, which do you want? A box rule is fine until it becomes so restrictive that there is no room left in it to move, then it is no longer a box rule but a ODC.

But in order to build an efficient variable trim boat; you would not build it the same as a standard boat. The beams would be in different places. The boat would be set up differently, the hull shape would be different. The stress loads are in different places, The boat would not look like a current F16.

Agree the Moth has florished as a result of the change. My point is that this technology would change our boats completly and as a result, we would ALL HAVE TO CHANGE our boats.

Remember all the Moths were trying to do is fly (i.e. reduce drag in the water)- I do not believe that this can be done within the current F16 rules and the changes proposed for this year). Variable trim rudders allow you to create RM and thus change the boat in a fundemental way.

Also interesting to note that the Moths are now talking about building boats that have a lessor aerodynamic profile and so fly batter (again increasing the obsolessance of the older boats).

I think I've said all I intend to say on the subject now. I feel people now know my views. These boats could be built, but as I've said I do not intend to (unless someone gives me some dosh). I (and others) believe this is possible and I am as far along the road as design for rudders to be automatic upwind and a single re-set downwind.

Regarding the T-foils and additional rules.

I think the best way forward is for Simon to find a F16 sailor who will support him and then work out a rule change proposal that the GC can process according to the class rules and eventually put it to the class for the vote.

Then everybody who is in favour can then vote to accept the change and everybody that is against can vote against it. That should be sufficient to conclude the discussion.

By now Simon will have enough replies to analyse what a crossection of the others think and adjust his proposal to maximize its changes of being accepted.

I'm not sure whether I have given my take on the T-foils yet, so here goes.

I think the T-foils are a golden opportunity for the F16's, especially for singlehanders. We are indeed more limited in hull length as other classes and the effects associated with that are already well covered but with T-foils these effects can be totally corrected. With them the F16's can even close the last remaining gap with the A-cats and the 20 foot spinnaker boats. The biggest advantage of these is the fact that the longer hull length does make them more relaxed with respect to diving. With T-foils this last remaining advantage will be gone and F16 can then be pushed very hard, even by novices, in rough conditions. Especially novice singlehanded sailors will appreciate the additional stability. This will give the F16 and excellent base from which to meet the competition both on the water and in the market place and for almost no additional costs ! I truly believe the T-foils are the last item to complete the F16 package into something that will be a succes story.

From my own analysis I don't expect much advantage at all of T-foils that can be adjusted while racing. For the same reasons others have expressed already plus the fact that permanently engaging them will add drag and they are too small and more or less in the wrong spot. However by the same reasoning I don't object to ruling that only T-foils can be used that can not be tuned or adjusted while racing (sailing). Even if the boat has to make a full stop and sit there for 5 secs in order to adjust them then that would negate all the potential advantage they could bring during continued racing.

So I envision a setup where the fine-tuning of the inclination angle of the T-foils is set by tilting the rudderstock at the sterns by some simple setup but where the T-foils are then set for the whole race/day. Maybe even a setup (eyebolt with pintle on the stock) that could be adjusted out on the water with the boat in irons for a while. And where the F16 class rules actively forbid the setup to be such that the inclination angle can be adjusted while the boat is travelling through the water or during a race (between start signal and finish).

I feel that development is bets allowed for the remainder.

Wouter

Weighting the tip is the worst place to add weight, because this placement maximizes the angular inertia of the mast more than any other place, increasing pitching (hobby horsing) in chop. When combined with a minimum mast weight, the tip weight creates an incentive for mast builders with high tech materials to instead make a internally heavy mast, which is likely to be more structurally sound. So, it makes sense to set the tip weight (and minimum mast weight) at least as high as the natural tip weight of the lightest proven-reliable carbon mast on the market, for safety.

I believe this "carbon safety" tip weight is likely to be less that the current rules' tip weight, acts as a valid safety rule, and does not significantly stifle innovation.

Even more weight at the tip is seen by some as a way to reduce the competitive advantage of carbon masts (a very one-design concept), and it can do so by rendering the C masts as heavy as Aluminum, with higher angular inertia if tip-weights are used, but stiffer... but that stifles innovation, does nothing to ensure Al mast safety, makes boats harder to right from a capsize, and increases overall weight. Since minimum weights are best achieved with carbon in the mast and not lead at the tip, it makes the best Carbon masts require more Carbon and therefore costlier, and only marginally better than Aluminum. So, you get to spend more money for less of an advantage. This sort of rule is an abomination because it makes people spend *more* money to get a competitive boat, and it stifles innovation by causing masts to be designed to a weight rule instead of designed to best use of materials.

Instead of mandating an Aluminum-mast tip weight, it would be better to either outlaw Carbon (the "level playing field" or "one-design" approach), or lighten the tip weight to levels appropriate for C (not Al) mast safety (the "safe innovation" approach). The F16 is an innovative class, which would be best served by the latter.

--Glenn

Isn't that pretty much where we are at the moment? The tip weight is already below that of a typical Alu mast, and based on limited information available, seems to be a little above what can safely be done with carbon.

Paul

This is exactly were we are now with the current tipweight rule. And this is exactly what was intended when we incorporated this rule.

I worked on several updated F16 alu mast designs (none in production at this moment) and a 6 kg tipweight is impossible to achieve on any dependable alu F16 mast.

Stiffness is NOT an issue in this as you can pretty much have any stiffness you want for a given mastweight by adjusting the crossectional profile. The issue is truly strength as at a certain point the wallthickness will become so small that the wall will easily buckle under the compression loads resulting in a total failure of the mast (=collapsing and breaking). But interestingly enough this can be corrected to some measure by pressurizing the alu masts, however this is a different topic. (Compare this to the russion inflatable catamarans)

Carbon masts are the same in this respect. Personally I always wondered why carbon mast builders don't use plain glass cloth to beaf up their mast in (wall) buckling resistance without affecting the stiffness of the mast much at all. Also glass cloth is CHEAP ! And if they do (I know some do) then why not use a little more plain glass cloth to get up to the tipweight of 6 kg without affecting the stiffness much at all while making the walls alot more buckling resistant (=dependability).

I would really like to hear a carbon mast builder tell us why this can't be done.

Wouter

But Wouter, you are asking the mast makers to add weigh to their mast because the rules say so.

The figures I have are that they can make masts lighter if they were allowed to. The rule we have in place are forcing the makers to make their masts over they weight than can make them to (or in fact add lead to the top to make them measure to the current rules). The figures I also have suggest that they could make masts about 1-2 kg lighter (all up weight) and remain more than strong enough to cope with the loads applied.

Wouter

You asked for some data to corroborate the claims that carbon masts can be made robust at significantly lighter weight, well here is my 2 cents worth.

We have to date built over 60 F16 carbon masts, we have broken 6.
1 was driven into a pub whilst on it's trailer, 1 was driven over by a car, 1 was broken whilst flying a 21sqm mast head kite, twin trapezing with the main flogging trying to get round a headland, and 2 failed because we built them to a special spec. and the last one had a ridiculous amount of diamond wire tension.

The first masts came from Holland composites, we then bought the mast mould and continued building them to their specifications.

About 18months ago I revisited the spec that we used and came up with a new laminate, the old one was plenty strong enough but I wanted a stiffer mast.

The old spec did indeed have glass in it and there is no reason why this cannot be done, however although glass is cheap, pre-preg glass is not, indeed unless you buy very large quantities it is almost the same price as carbon.
And as you say you can pretty nuch put as nuch as you like in there without effecting stiffness.

Anyway the new mast spec gives a tip weight of 5kg, I just weighed one with diamonds main halyard, and spinnaker halyard in it 5.05kgs.

Purely by coincidence the guy who broke the last mast is a structural composite consultant, he works on very large multis, did Ellens boat and mast, and is doing some giant in Australia at the moment, his credentials are impeccable.
He wanted to ensure that his next mast was stronger and stiffer as he sails with his crew at 190kgs.

He ran the calculations on both our mast specs, the old one had a Euler buckling failure of 1.8 tonnes, and the new one is 3.3 tonnes.

Back to adding glass, the old mast had a significantly thicker wall than the new, carbon is just a hell of a lot stronger that glass, I see no point at all in spending more time putting glass in adding unnecessary cost and weight to a mast that is clearly more than strong enough. I am sure that my customers would not want to pay the extra for a mast that is stronger than it needs to be and heavier than it needs to be, they will simply strap on lead for events that require it and take it off for club racing.

For our mast which has a bigger cross section than the superwing it is a fact that we could reduce the weight and still be strong enough, however the mast would not be stiff enough for our purposes, so it would be slower, so from a strength point in order to get it stiff enough it is overengineered on strength.

You say that stiffness is not an issue since you can adust the cross sectional profile, and you are right, however to do this you need to build a new mould every time, this is not a practical suggestion.

Thank you very much John Pierce,

Finally somebody who is willing to go on record with this !

You've provided some very interesting info. I wonder if we can get some of the other carbon mast builders like Fibrefoam and Saarberg to contribute to this discussion in public.




Naturally I was commenting on the engineering side of the topic. Here stiffness is not a big limiting issue. I was not suggesting that customized stiffness distribution was to be implemented by using different crosssections. Basically what I was saying that a crossection can be chosen as to satisfy the most flexible mast bending requirement where the mast walls are solid enough to handle the loads and (off the water) abuse. From then onwards the customizing can be done by adding cloth were needed (making the mast more robust simultaniously). In effect the first case determines the mould and with this mould all customized masts can be build.

I write this in clearification of my comments earlier to other forum readers. Naturally you and I were on the same page already.

Again thanks alot for providing us with some hard data.

Wouter

And worse still, I'm asking the hull builders to add weight to the F16 hulls because the F16 rules say so as well !

But seriously, what you saying is actually the core principle of a formula class rule set. Some claim that 18 foot long hulls are way better for a singlehander, but the F16 rules demand the hull to be equal to or shorter then 5.00 mtr. Same with the minimal ready to sail weight, the Marstrom M18 has proven that an 18 foot long spinnaker singlehander with F16 specs for the remainder can be build at 80 kg ready to sail. Still the F16 class demands that the boats weight at least 104 kg in 1-up mode. All these limitations on what CAN be had technically were not the result of us not knowing any better a few years back. Under all rules there is a balancing between technical capabilities and economic c.q. perceptional considerations.

More often then not a formula rule framework asks the builders to build something to a lesser degree then can be had with cutting edge technology. This is the core intention of the rules and rule makers as this prevents an arms race and garantees economic feasibility. So I will argue that the fact that something CAN be build to more impressive specification is in itself not an sufficient reason to claim that a formula rule framework needs correcting. In most cases limiting this possibility was actually the intention of the rule in the first place.

A far more persuasive argument can be had whether the reasons for limiting this possibility are still present.

I feel personally that times maybe changing and a revision of the reasons that gave birth to this particular rule may be in order.

Wouter

Just a little about carbon masts that most people are unaware of.
Firstly most people relate breakages of carbon masts that occurred with A class masts in the past to the same way that aluminium masts broke. That is that the aluminium section under extreme bending/shock loadings folded on the compression side of the section and bent etc. With a carbon section although the end result may appear the same that is not exactly what happens. In layman terms we can say that carbon fibre has enormously good properties under compression but is far less strong under tension/stress/twist loadings, so that unlike an aluminium section that will “fold” on it’s compression side wall, in the same type of situation a carbon mast “breaks” on the other side of the section wall I.E the fibres are literally pulled apart on the tension loaded side. We extensively tested “to failure” several standard sections of carbon A class masts before we decided on a carbon laminate for our masts on the F14 and we found that in the vast majority of breakages that occurred to the A class masts all failed approx 600mm to 800mm below their hounds and had literally been ripped apart on their tension side. This 600 to 800mm distance is where the greatest load will occur on a mast when it is “slapped” onto the water forcibly. The hounds act as a fulcrum and the diamond wires restrict the section below the hounds in their ability to “flex” and disperse the shock as much as the unstayed section above the hounds. To obviate this potential failure in our sections we simply have added a section “patch” of 300gm/sqm of Kevlar to the laminate from just above the hound location to approx’ 1m below the hounds. This has to date proven completely successful and apparently seems to have made our mast sections “bullet proof”

May I ask what the unit weight of your masts are Darryl. Is it near the 1.1kg/m that has been suggested previously in the post?

With kevlar reinforcing the BARE mast section weighs 8.6kgs for a 25' length section (you can do the equivalent maths conversion - though somewhere near 10 to 11 kg for an F16 BARE length) the 25' length fitted is 10kg (plus or minus) for a section for an F16 the per metre weight would probably increase slightly as we would modify the ratios of the laminates

In this post I do the unit conversion and the math for our forum readers.
The statements in this thread do not convey my personal take on the issue in any way.





F14 carbon mast (25 feet long = 7.62 mtr) :

8.6 kg / (25 * 0.3048) = 8.6 kg / 7.62 mtr = 1.129 kg / mtr

If this particular bare mast were 8.5 mtr long (F16) then it would weight ; 8.5 mtr * 1.129 kg = 9.593 kg

Using the earlier stated rule of thumb : tipweight = 1/2 * bare mast section weight + 0.75 results in.

1/2 * 9.593 + 0.75 = 5.547 kg tipweight.

In my calculations I found that the fittings themselfs add 2.64 kg to the mast and 0.827 kg tipweight. If lightweight spreader arms are fitted (proctors are relatively heavy) then numbers are 2.40 kg and 0.75 kg. Hence the use of the 0.75 number earlier.

With this averaged info we arrive at a F16 carbon mast, based on the F14 specs, that have an overall weight of about 9.593 kg + 2.40 kg = 11.993 kg. = say 12 kg overall. And this EXCLUDES the weight from the halyards and trapezelines !

These halyards (main and spi) are about 200 grams = 0.2 kg per 16 meter. And so these add 0.2kg to the tipweight while adding 0.40 kg to the whole mast. 4 high tension line trapeze lines are combined 0.2 grams and add 60 grams = 0.06 kg to the tipweight. These are pretty much neglectable in the overall picture.

So our estimate of the F16 carbon mast based on the F14 carbon mast comes out at :

Overall weight = 9.593 + 2.400 + 0.400 + 0.200 = 12.593 kg = say 12.5 kg
Tipweight = 5.547 kg + 0.200 + 0.060 = 5.807 kg = say 5.8 kg

As a comparison : the Alu superwing (Taipan, Blade, Viper) mast has the officially measured (averaged) specs :

Overall weight : 18.0 kg (and 20 kg including the 4 mm thick stainless steel standing rigging)
Tipweight : 8.25 kg (excluding the standing rigging)

At 85-90 kg dry body weight I have never encountered problems righting my F16 (which is 121.8 kg ready-to-sail when fully sloop rigged)

The Stealth specs are given in the post by John Pierce earlier.



Also note that Darryl wrote :



Also note that some weight savings can be had by using very lightweight fittings and a push up mainsail. But also note that these change will not alter the calculated tipweight much as the above example shows.

Interestingly enough these calcs mirror closely the calcs that supported the 6.00 kg tipweight rules choice in the past.

Wouter

Using the data gethered in my post above we can estimate the difference in righting between an Alu and carbon mast, this may be of interest when balancing the pro's and con's.

Additional data is that a pentex mainsail itself will weight 5.5 kg with a centre of effort at about 4.150 mtr up from the mainbeam. With a mast angled downwards (10 degrees) in a capsized position the leverage becomes 4.150 + 0.220 mtr = 4.370 mtr= say 4.50 mtr. This results in an added virtual tipweight of about 4.5/8.5 * 5.5 = 2.911 kg

The 94.5 kg platform (using a 12.5 kg mast on a 107 kg ready to sail boat) is also angled at 10 degrees and thus also provides some additional virtual tip weight of (sin(10)*1.25*0.5*94.5) / 8.5 = 10.256 / 8.5 = 1.207 kg

So the total virtual tip weight of the whole craft on its side is :

Alu mast = 8.25 + 2.911 + 1.207 = 12.618 kg
Carbon mast (12.5 kg total) = 5.8 + 2.911 + 1.207 = 9.918 kg

In effect the carbon masted boat takes 9.918/12.618 kg = 79 % = say 80 % of the righting moment that the alu masted F16 does.

And a tipweight lowering of 1 kg results in :

5.00 + 2.911 + 1.207 = 9.118 kg tipweight => 9.118 / 12.618 = 72 % resulting in a 7 % gain in righting ability.

If 100 % equals a 85 kg skipper (me) then 7 % improvement of righting constitutes 5.95 kg less skipper weight needed to right the boat relative to the current tipweight rule.

It is to the class members to evaluate if this is enough of a reason to propose and support a class rules change.

To give some perspective to these calculations. If we assume that it takes at least 85 kg (=me) to right the alu masted F16 in ALL conditions including no wind and perfectly flat water (a very demanding condition) then it requires 67 kg to right the F16 with a carbon mast compliant with the current rules and a 61 kg skipper if we lower the tipweight rule to 5.00 kg.

Many of us have indicated that a little wind makes righting the alu masted F16 significantly easier, probably requiring only 75 kg to right the alu masted F16.

Wouter

So we are limiting persons to 61kg who can sail the boat single handed. There was a lady at the A class Nationals at Mumbles who was 58kg - so she cannot sail the boat !

Edit to add - Wouter, do you calcs take into account your height - if so we are limiting the boat to persons of 61kg the same height as you ?

Are we really ?

Is it impossible for a "61 kg or less" skipper to use shroud extenders, righting bags or other righting aids ?

In the end of the day there is going to be a threshold somewhere with individual sailors falling on either side.

The paramount reason for the formula rules is to equalize performance over boats of different make, not to garantee that some extreme skipper can right the boat without additional tools.

Wouter

It would be really neat to see an auto-trimming foil like shown in the attached sketch. The concept is similar to the Ketterman trifoiler, where the foils automatically generate negative lift on the windward hull when it wants to fly, increasing righting moment.

Glen;

My approach is similar, but uses cams within the foils to do it.

Foiling is not how it seems . It is the leeward hull that rises on a Ketterman Trifoiler, not the windward. The drawing you have added would lift the stern and bury the nose on the windward hull and the opposite on the leeward. If it were foiling it would raise that hull but that would be exactly what a foiler would not want. We dont foil on catamarans so trying to use a foil to balance the boat rather than sailing it balance must be couterproducetive. T foils temporarily correct an ill balanced boat. That is why they are so effective.

Have a look at the following for how the Ketterman works. It's very interesting.http://www.hobiecat.com/support/pdfs/trifoiler_manual.pdf

Maybe I did not make it clear. My design would create lift from the leeward ruddder and "drag" from the windward rudder. So pushing the stern of the leeward hull "up" and the pulling the windward rudder down. This will result in considerable twisting moment within the beams / hulls, this is why I believe the a new beam / hull layout would be needed to make the most of this.

When you say "drag" do you mean "suction" or "negative lift"?

Drag is usually the term associated with a force acting against the direction of motion. For lifting foils this is a horizontal force. This would not pull the windward hull down, generally speaking it would just slow the boat down and make it yaw to windward.

If you're talking about suction or negative lift then yes it will increase the righting moment of the boat.

I think he means "upwards" lift on one foil and "downwards" lift on the other, which are both positive "lift" but acting in opposite directions. (which would create quite large additional twist loadings to the beams and beam mountings if it was to be effective particularly with it acting at the stern(s))

YES, negative lift in order to create RM

it was late

But cats already are being twisted significantly under the rig loads. Off the top of my head, I think the T-foil would only reduce the twisting loads or maybe reverse them a little in special cases (high angles of attack on the foil).

What size foils are we talking about here. If you're talking about say 400mm * 150mm, you'd probably only get about 40kg of up/down force at an efficient angle of attack that doesn't create too much drag. If you want anymore force you're talking about foils on each rudder the equivalent of the total area under a moth (700*150 and 600*130 -ish)! They're gonna be very big, feasible but big. And I believe the foils are included in the beam measurement of the F16, so they will likely have to be L-foils, not T's, which will be even trickier because of the structural issues.

Just quickly read the rules again, I'm not sure if the centreboards or rudders are now included in the beam measurement. It says "overall beam" which I take to mean beam of the boat when taking everything into account in its normal position...can anyone clarify?

I'm need to think about these rudder foils some more...

Rudder ends or T foils are not included in the beam measurement.

I've not done detailed calcs, but if you are saying we can get 40kg per foil, then that is an extra person for virtually no drag. Makes it sound like a no brainer that every one must have them, or we ban them ?

Thanks for the clarification. This is good because T-foils are much easier to build strong enough.

I was about to blow up about my guesses being used as facts but decided to do the calcs instead...lucky...my calcs indicate that a force of about 90kg with a 0.05m^2 foil may be achieved with about 2kg of drag at 20 knots. It's all rough numbers anyway because boats will pitch and heave which will change angles of attack constantly.

I personally think it is going to be exciting being in a class that has this sort of development. I will certainly participate...if it doesn't get banned...

You still haven't explained why you are promoting a banning of rudder foils because of the cost, but then you are promoting a rule which will make expensive carbon masts more favourable, in terms of performance and safety apparently, against the cheaper alternative...?

As I said previously, the rules are good as they are, for the moment. Those that want to develop can do so with very little risk of blowing away those ppl that want to buy a production boat off the shelf. I think it is a good balance at the moment.

If someone doesn't want to be part of a restricted development class, there are other classes more suited to their tastes.

Carbon masts are a known quantity when it comes to cost, but variable pitch T-foil rudders are an unknown. We dont know what they will cost if they are ever implemented, debugged and turned into a race winner. To me it dont make sense to ban then before we know more, but others want to stop the development before it passes from the stage of an idea.

I'm proposing to propose (if that makes any sense) to allow carbon masts to be built down to a level at which they can be built. John P has already confimed that his masts are built to design and not to a weight and so I believe that his masts may need correctors to measure. He has stared that he believes his masts are more than strong enough to withsatnd the loads. Has anyone asked John to quote for a Carbon masts only and compared this with an appropiate Alu section? I'm simply sayinmg that the tip weight rule limits who can sail the boat (yes they can carry righting bags or pole, but would someone want to ?)

I propose to ban variable trim T foils because I believe they will make all current boats obsolete.

Nope. On the trifoiler, both windward and leeward foils seek a fixed depth, thanks to the forward "sensors." In lighter winds, both foils generate positive lift. In high winds that would otherwise capsize the Trifoiler, the windward foil generates negative lift to seek the target depth.



The vertical coupling is meant to be cable, which cannot push, and therefore cannot cause the foil to generate positive lift and bury bows. The feedback system therefore generates only negative lift and cannot lift the sterns. Adjusted properly, it would only increase negative lift (and drag) once the corresponding hull lifts clear of the water, since there is no point in the foil increasing downward lift when the hull is still in the water!

The traditional T-foil property of generating negative lift as bows dive should be maintained in this system not by the feedback system, but by limitting the rotational travel of the horizontal foils. Such as system would always hold the sterns down at least as well as traditional T foils (and better when the windward hull rises).

A valid concern about the system is that that the additional righting moment would mean one could sail much hotter and faster downwind in high wind, but in doing so you risk stalling the windward foil and pitchpoling suddenly at speed. (But this is somewhat true of T-foils in general, I theorize: once the windward one clears the water it suddenly stops down-lifting, and the hull pops and the bows bury.)

I am not sure a foil would generate 90 kgs of lift for that little drag. Can anyone concur that statement as I'm a dummy with maths

At 0.05 m>2 this would mean a practical foil with a modern section and aspect ratio of about 1.25 metres long x 75mm wide. Now the loading would be so high at the tips that a huge amount of carbon would be needed such that I would doubt that you could construct such a wide beastie. OK reduce the width to say 75cms which is still a really wide wing on a rudder, down comes the aspect ratio, up goes the drag, add in a few dings etc and surface impections and up goes the drag even further, mmmmmm not looking so good now.

For all those maths boys, how much force in regards to foward motion does a F16 Spinnaker actually produce, I bet its not that many kilos as one can fairly easily hold on the sheet which is taking probably more than a third of the load. Interesting calculation

Yes Glen on my Stealth when the windward T foil comes out of the water the leeward bow immediately buries, fortunately the Stealths have ample reserve in the bows and generally the boat wants to submarine along its length to such an extent that the drag slows the boat and the sheet loads go so high that one tends to dump the sheet rather than pitchpole.

Still not convinced that in a practical sense adjustiable foils are any worry, if in doubt simply put an upper limit on the foil sq mtr size.

Have a read of the tri foiler manual. I put the link on the last posting. In it Ketterman explains why the leeward foil rises. You will find it interesting. Or maybe have a go on a tri foiler! <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

It would seem to me that unless a person has quite a lot of personal, PRACTICAL, hands-on experience with foils OR they have been involved in AND understand fully the maths, they should be very careful entering into debate on this subject in any way other than subjective curiosity as most of what is being written here concerning foils is pure conjecture and in many ways misleading, which could very easily lead to banning something for entirely the wrong assumptions.

Ok, with T-foils you are making a distinction between variable and fixed foils. So you are only opposed to variable foils.

Still a bit iffy about the mast tip weight rule change but I guess I need to become an F16 association member soon and vote on it. Can I get voting rights before the boat is finished and measured? I may have issues getting measured since there are no class measurers within a days drive of me...that I know of.

Disclaimer: The numbers I generated for T-foil lift are very quick and theoretical based on a set of lift and drag coefficients for a slightly incorrect reynolds number (about twice as much as it should be), so they are technically wrong. I believe the drag only takes into account induced drag; no friction, aspect ratio, etc. drag. It is true, practical foil design is fairly different to theoretical design.

The foil I had in mind was 500mm * 100mm. My mate has a higher aspect ratio foil (about 800 * 75mm) on his moth and I'm not a fan of them for boats, too much fluctuation in angle of attack (due to varying speed, yawing, pitching), which high aspect boards don't like in general. They tend to stall at lower angles of attack than lower aspect ratio foils.

There is a vast difference in the performance (efficiencies) between a “straight” high aspect foil with a small flap on the trailing edge and the same high aspect ratio foils raked backwards with the whole foil “turning” (up and down). Then to complicate matters even more if very small “tip winglets” are added then the efficiencies increase dramatically again. (The adage applies – “There are many more than one way to skin a cat”) Consider that a low aspect ratio foil set “straight” to all intent and purpose becomes a much higher aspect ratio in practice when raked, it’s chord length becomes much smaller in ratio to the surface that it is exposing to the direction of the fluid travelling over it. (If these principles hadn’t been exploited they would still be trying to break the sound barrier in aircraft today)

My assertion that the windward foil can generate negative lift in high wind is based on a vector diagram drawn by Mr. Ketterman himself, which I saw years ago. Nothing in the tri foiler manual contradicts this.

Yes there is all sorts of foils but hydrodynamics has been around a long time now and there is an awful lot known about it. My question is and still hasn't been answered is the following. How much actual drag will there be created from a foil of 0.5 metre sq and how much force can a Spinnaker create in foward motion.

Maths boys, and there are a number of you who regularly post on this forum, get your calculators out and do the sums for us dummies and please don't go all shy on me, show us your credentials. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

There is no answer to you question in the form that it is. For both parts IE foil - the drag is a variable calculatable only with additional criteria. the same applies to the "power" generated by the sinnaker

Very dependent on speed of flow around the spinnaker or foil, angle of attack, etc. etc...The question is too vague.

A vague answer about the force on the spinnaker...

As long as the boat isn't accelerating...

The force from the sails is equal to the force of drag on the hull and appendages, just in the opposite direction. (This is on all points of sail, upwind, downwind, reaching...)

Probably a big percentage of that force is developed by the spinnaker.

Glen, Give it a try and make some foils! I would hate to stop progress! If ever you are in the UK give me a call and come and try the only 2 tri foilers in Great Britain! Good Luck!

David