Please explain some of this to me. Please make it understandable, not in Engineer-speak, or formulas or frequencies.
Just in plan and simple understandable English, Preferably in lbs. instead of kg. too.

1. I understand there is a difference in the overall weight of the Aluminum Superwing Masts and the CF masts.
2. It also seems from the discussion that some of this equilibrates once you add hardware to the mast, since for some reason unknown to me the CF mast hardware must have to weigh more than the Aluminum Mast Fittings.
3. You don't want to alienate a group of Cats already built which can meet Class specs with a weight compensator. We do that in all the Formula classes to allow for variations in crew and boat weight, No one has come up with a better solution yet that I'm aware of.
4. It seems if you only drop a small amount off the current weight tip requirements you can still accommodate these underweight-masted boats within class regs. (sounds reasonable, I can't vote on this not yet being an owner, but I still have my opinion about keeping things simple so the most people can participate in a class on equivalent terms)
5. There is some argument that soon CF Masts will be as durable as Aluminum. I'l like to know how to splice a CF mast or weld a crack or hole. My take on that is that You can Repair Aluminum, you basically can't fix a CF mast, and the CF masts are more prone to failure. For Example, My 1999 Inter 20 is on mast #3, that equals < 2 years on a CF mast. Our other 1999 Fleet I-20 had so much wear and Degradation to the Mast, I was amazed we got it through the Tybee500. CF MAsts have to be treated with extreme TLC, or they get wear spots and Weak spots. CF is also prone to Failure due to UV degradation. So we are supposed to keep our masts out of the sun to avoid this. What's up with that on a beachcat? Are we only going to go nightsailing?
6. Some discussion that CF is going to be cheaper than Aluminum: Even the Implication that there will not be a supply of Aluminum masts to the Manufacturers. (Is there some projected world shortage of Aluminum that I'm not aware of? MAybe we should all go out and collect aluminum scrap so we can melt it down for our future masts)
7. Finally: We talk about the relative righting advantages of the CF Mast, but the Compensating weight we put on the Tip of this Lightweight Mast Is going to add all the weight to the top of the mast which is according to my rudimentary understanding of physics, going to magnify the lifting (righting) energy required by the distance(mast height) x counterweight mass. All this will increase the righting difficulty even more than having this same weight evenly distributed along the length of an aluminum mast.
It should have the same magnification of effect (Distance x mass) since it is positioned at the end of the stick as the inertia of the counterweighted mast tip waves wildly 30 feet in the air.
8. Someone please, help me, I'm into Wouterspeak here.
CARY

This is a great idea! Finally a useful purpose for all our empty beer cans. And maybe a way to get sponsorship -- "This mast was made from recycled Budweiser cans."

Zuhl, thanks for asking those questions, because I have been totally lost about this, too, and we actually own an F-16 (Taipan 4.9) but don't understand the masttip weight thing. (We don't understand "wouterspeak" either.)

You have made seven statements, what questions are you looking for simple answers to

I don't know about Zuhl, but I have a simple question, and maybe it is a really dumb question, but why would anybody, for any reason, put a weight at the top of a mast?

(I guess I should add, unless it was for flotation purposes.)

Seven Simple answers would be good.
ONe woudl be even better, I'm referring to Mary Well's post here. Why would anywone do that in the first place?
Was supposed to be a simple question, each thought ended with some unanswered unexplained piece, I guess I know how Wouter's posts get so long now.
CARY

There's an interesting comment from Andy Rice in the current Yachts and Yachting. Having broken the top 3 feet of a carbon I14 mast, they were sailing with the same mast a few days later and have continued to use the same one since without any problems. As he says, do that with an ally one and it's time to buy a new mast!

Simple minds, Simple questions.
Wish I was as concise as you.
I like the way you boiled it all down into one statement.

CARY

Alright,

There are two ways about this. You can either put your faith with the engineers and designers like Phill, Jennifer, John and Myself (I count the other class heads as valuable members of a different stripe. And trust that we 7 class officials make the right choice. OR you can try to understand the issue as best as you can and lets your opinion be know.

I will now continue with the second approach :




F16 class rules specify that all values must be expressed in SI (International system) units. Seconds, meter, kilograms. But I will put conversions into brackets. But it is time that the two nations left in the world convert to SI units as the other 178 nations have done. I know its origin is French BUT it does really work better than "3 feet in a yard, 12 inches in a feet, how many in mile ?". Sorry just a pet topic of mine.

Anyways.



Correct, but teh difference can be less so than when looking at density numbers. Simply because other constraints like minimimum wallthickness limit the weight savings. Note that weight savings in itself don't help you under F16 rules because of the overall minimum boat weight. You can only reinvest the saved kilograms.





There is no reason why carbon mast fittings HAVE to weight more. At least not enough to make a significant difference in overall weight or tip weight. They fact that some carbon mast do have heavier parts has to do with choices made by its designer. Ease of building can be one of the driving factors. Of course relatively speaking the fittings make up a larger part of the total weight when looking at a carbon mast that is because the weight of fittings don't change while the section becomes lighter. Ergo they make up a larger percentage of the total. But this is different then what you say.




This is not a question but a statement. I would like to add : We, as a class, don't want to write the rules in such a way that we favour the Alu mast over all alternatives or the other waya round. We wish to allow maximum freedom of design without risking significant difference in all-out performance. Equal performance ON THE WATER is paramount not equal performance in mathematical models or under laboratory conditions.





Only the doublehanders. The specilized single handers are probably out of luck. The "good will" stops somewhere. But we probably get the biggest group included this way AND we keep some margin of superiority with our closest competitors. The added weights to the guys falling outside of the rule is still limited enough to not hurt them. In all honestly the 6.5 kg tipweight rule will work but the 6.0 kg tipweight rule will work slighlty better. After this the rules will be fixed for years to come so I want to be sure that we don't regret the compromise that we reach.

Also we let it be known that after this will be BAN any crew from racing when his mast is found to be underweight with respect to the tipweight rule. We hold the builders responsible for any failings in this area. No more pardonning.





Actually what you are pointing out to us is that carbon mast are NOT preferable in all aspects. Something that most sailors simply forget. There are some noteworthy drawbacks of carbon masts. And their are some noteworthy advantages of alu mast. One of this things is the extended adjustment range of alu masts. This is to be prefered on boats that are used frequently in both singlehanded and doublehanded sailing. I will say the following only once, so take note, I will personally not switch from my current alu to carbon even if I can do that for free. The alu suits my way of using/racing the boat better. And as a added bonus I don't worry about leaving it standing on the boat or UV degradation.





These are mostly scare tactics, brought into the world among others by the Tornado class and Marstrom to force a yes-vote on the carbon rigs. My personally experience is, and I worked the superwing mast deal for the last 3 years now, is that there is NO problem with supply OR cost of alu masts. We don't expect any to develop in the near future. On the other hand a greater urban legend is the fact that carbon is expensive. It is indeed MORE expensive THAN alu in as good as all instances like poles or booms and masts but that doesn't make it expensive outright. It is not even near to as expensive as Marstrom and some carbon mast builders make you believe. I will have to suffice with a simple example : I could order a carbon mast blank at Stealth Marine for 750 UK pounds = 1085 Euro's; My superwing at that time came in at 880 Euro's. Both for bare sections and including taxes; profit margins; the works. Seriously those 300 Euro's is peanuts on a whole boat. The fact that mast builders request between between 1700 and 3000 Euro's for bare sections (Hall spar even more I believe) has everything to do with profit margins and earning back development costs. With respect to the last point it must not be forgotten that the design and making a NEW alu mast creates about equal development costs.

Take from this that alu mast sections are still cheaper than carbon mast sections (the fittings are of course the same) but the difference between the two in REAL cost (no profit difference or develop cost differences etc) is less than 300 Euro's. To give a nice comparison I think alu Hobie 16 masts are more expensive than Stealths Carbon mast. We must take great care to seperate the myth from the fact. So it is wrong to just say carbon is always more expensive than alu. This dependents entirely on who is selling you the mast.

One more thing; currently we don't expect any carbon mast development from the Taipan and Blade builders as none of these see the (ASSUMED) potential benefits outweighting the required investments in time and tooling in any significant way. That Superwing alu mast is really regarded as a difficult benchmark to beat already. Only really pressing reasons can change that and pretty much only political or perception reasons can scale up to that as any performance reasons are just too insignificant. In some cases performance reasons may well even favour the aluminium. Again don't fall for the myth.




There is some core of truth in what you say but you are still wrong. The way the tipweight rule is currently written does NEVER increase righting past the level of the theoretical lighest allowed F16 mast. This level is curently at 62 kg ( = 137 lbs) with 6.5 kg tipweight and will be at a shy 57 kg (= 125 lbs) with a possibly new 6.0 kg min tipweight rule.

Say a mast is underweight AT THE TIP, say 5.0 tipweight, than adding 1 kg to the tip will end up with a mast that can be righted with 57 kg's on the righting line ; just as the min theoretical allowed F16 mast. So we don't hurt anyone in righting, we do make it unattractive to intentionally build underweight masts as you can not gain any righting advantage with it.

NOTE : take my word as an engineer. Adding (more) weight along the mast to make this 5.0 kg mast have a tipweight of min. allowed 6.0 kg WILL NOT MAKE ANY DIFFERENCE in righting with respect to adding (less) weight to the tip of mast to end up at the same 6.0 kg.

Take good note of that. Things are a little different when looking at dive recovery and swinging about but not in the case of righting.




This does not factor in in the way your present it with regard to righting. But is an explanation why a 6.5 kg tip weight on say an I17R (if it is goes that low) that has a taller mast, IS MORE DIFFICULT to right than 6.5 kg at the top of an F16 mast. (Difference in such a case would be 4 kg's in sailor body weight)





Who better to help you than Wouter Himself !

Or is that a contradiction ?


One more thing though.

The talk you had about the difference in distribution of weight along the mast does factor in with repect to dive recovery and swinging about in waves. However because we have limited mast height to 8.5 mtr. the depencdency has been severaly limited (note this difference between us and the A-cats ! It is an important one !). I won't go into detail as that will require more in depth knowlegde of scientic and engineering principles.

By this interaction between two F16 class rules we end up with a situation where a tipweight rule WILL penalize underweight masts by making them less efficient in dive recovery and swinging than the min allowed theoretical mast HOWEVER only PROPORTIONALLY to the amount of being underweight ! This is a great way of allowing freedom and still force compliance with the rule set. Simply put

-1- You are only disadvantaging yourself by having an underweight mast; so why do it ?
-2- You are only penalized proportional to your magnitude of your non-compliance so if you are underweight by a neglectable amount due to some quality control issue than your disadvantage is equally neglectable.

With both the 6.5 or 6.0 tipweight compromises the Alu superwing is still very close to the optimal rig to make any POSSIBLE differences in performance negelectable. These may go EITHER way as alu has some sweet spots as well ! This is because we need to add the contributions and behaviour of sails etc to make a proper comparison. Any MAXIMUM differences are prejected at a fraction of 1 % and as said earlier is to be compared to buying a new jib every year. If you buy a new mainsail as well than you will have gained a multitude of gain. This is the order of things we are currently talking about. AND AGAIN, the advantage may well fall either way. Proper mast design is so important that an alu mast section can be just easily better than the carbon mast as the other way around.

I hope this helps,

Wouter

Ok

seven amswers

1.) carbon masts are lighter

2.) mast hardware for carbon masts does not have to weigh more than for aluminium

3.)I don't see a question to answer, you need to put it in simpler terms

4.) see 3)

5.)carbon fibre masts are very easy to repair.

6.) No-one said that carbon masts will be cheaper than aluminium, they are getting cheaper all the time, but will probably always cost more because they take longer to make, but on a $13000 boat an extra few $100 is not that much, there is no shortage of aluminium expected, but there is no shortage of wood either, but we don't have wooden masts anymore because aluminium is better

7.)No, the tip weight is measured by placing the mast horizontally, supporting the base, then weighing the tip, to achieve the same tip weight the carbon masts will be still end up lighter, but to lift the tip clear of the water will be the same for all masts of the same tip weight.

And to answer Mary's point, the only reason to add the weight is to make all the masts soak up the same energy when the mast is wobbling about.

Mary and others please prepare yourself for this one as the truth is a little confrontational :





Because other sailors without any engineering skills/background PERCEIVE that they will be uncompetive if such a thing is not done to some other crew despite the fact that the theoretical differences are too small to measure anyway.

Scientifically speaking there is no reason to suspect that a well designed F16 carbon mast is noticeably better (or worse) then the well designed lightweight Alu superwing section. However this doesn't prevent the bulk of the sailors to have a gutt feeling that says otherwise. For some reason people tend to trust their gutt feelings over verifiable science.

Take a look at an analogy :

Why would any person prefer 6 liter V8 diesel engines over the newest generation German 2.4 liter V4 diesel engines ? With the extra gear shift the last beats the first hands down in all aspect. From overall weight to road speed and pulling power to fuel efficiency. But still the gutt demands attention ....

Wouter

Do not make the mistake of extrapolating any experiences with carbon masts in the A-cat class or Tornado Class to the F16's. If you do that then you simply don't understand how the F16 class rules work. Even if we would delete the tipweight rule now, we still won't be able to make the same gains as were made in these classes because of the very lightweight of the alu superwing section and the fact that OTHER F16 class rule limit the gains as well.

Wouter

You can't repair alu F16 masts. That is a misconception. Certainly not by welding. Wrong alu alloy and wall is too thin for that. You'll end up with either a bigger whole or a wobbly wall that will give rise to buckling instability.

Repairing carbon masts is not for the amateur as well.

Of course very small damages can be patched up by amateurs but this is not the same as repairing them.

Professional mast builders can repair carbon masts as well as alu masts to SOME extend.

However for us normal sailors the rule is : Break/damage a mast => buy a new one.


Wouter

I guess I have missed something here. Probably have not read everything very carefully, because there is so MUCH to read.

I understand why you want to make the masts all equal in weight. What I don't yet understand is why the equalizing weight has to be put at the TOP of the mast. Why can't you have a strip of something that goes all the way up the mast or why can't you just use a halyard lined with lead (for those that use a halyard)? Well, you know what I mean -- distribute the weight.

Sorry for asking the question AGAIN. It's the TOP (or TIP) thing that I don't understand.

That is not correct; we allow (some) differences in overall mast weight while focussing on equalizing "swinging" behaviour.





That is because this allows the most equalizing in "swinging" behaviour for the smallest amount of added weight. We are trying to avoid making the mast needlessly heavy. Note however, that 95 % of the sailors will not have to add anything to their masts !

So reasons against distributing weight ;

-1- Adds more weight to the mast than needed to equalize things.
-2- too diffult to implement (source strip were ? Were fit the strip ?)
-3- too easy to remove right before the race (leaded halyard)
-4- Will interfere with the bending behaviour (strip on inside mast ?) and thus impact on alot more than the "swinging" behaviour
-5- For some engineering reason the mast designer DIDN'T distribute the weight over the mast. Why go against that ?


Actually putting the weight at the top is the working core of the rule, not a side effect or something we can alter without losing the intended effects.

Also it is very easy to either put corrector weights on, in or next to the end cap of the mast at the top. Won't interfere with flow over the sails and as said before it minimizes the required weight of the correctorweights thus keeping the overall mast weight as low a possible while forcing equality. It is also easier to keep masts watertight that way.

We must all note that we are talking about a TIP weight measurement NOT a measurement of overall mast weight.

Wouter

Just a few points of misconception.
Carbon fibre masts, even "snapped" in two, can be repaired relatively easily by any one with knowledge of "epoxy" FRP. The damaged area can quite easily be "sleeved" internally and glassed with very little difference from its original characteristics. Holes can be reglassed similarly. Any "wear" areas can be protected with a thin, small "sleeve" of "molded to the section profile" carbon fibre glued to the area and used as a sacrificial replaceable protector. This thing about UV degragation is no different from the fact that ALL resins break down under the influence of UV, even the hulls of any FRP vessel, - that is why there is gel coat or paint on the hulls of all FRP boats - so the usual way of protecting a carbon mast is to coat it with a layer of clear, two part poly urethare, then there is no UV breakdown, no one would even think of having the hulls of their boat finished in FRP without any paint or gel coat so why would you think that FRP masts should be different?
Carbon masts essentually fall into the same type of construction as the FRP hulls of any boat, just built to different tolerances, so that most of the maintenance and repair techniques that apply to FRP hulls, apply equally to FRP masts. To help give carbon masts a much greater resistance to breakage through impact when dropped or when the cat is "pitched poled" (which is the most common time of carbon fibre mast failure) we have had added a laminate of kevlar as the second laminate in our carbon fibre mast lay ups, this has increased the "toughness" of the mast enormously without adding to the weight.

OK Wouter
I seem to have stumbled on something else here. Tell me about the difference between the Alum Superwing mast and a standard aluminum mast extrusion.
CARY

Yes, I would like to know, too. What is a Superwing, and how do I know if we have one?

Mary,
If you have a Taipan it would have been fitted with a Superwing. The Superwing was designed by AHPC and they fit it to all the T4.9s.

Cary,
The difference between standard and Superwing as well as other wing mast sections is basically the shape of the mast.
From memory I think the dimensions of the Superwing is 63mm x 126mm.which is a ratio of 1to2.
The standard shape of an aluminium mast is more like the shape of a pear than a wing with a ratio of 1 to less than 2.
So comparitively speaking the standard mast is fatter and pear shaped while the Superwing is more of a wing shape.

There were other types of wing sections.
Below is some of my observations over the years as I recall them.
The first aluminium wing section that I know of was the Sori section. We imported them from Italy for the A class in the early 80s. These were in the days when we still had pin head sails and the Sori section used to be tapered and this plus the importation costs made them quite costly. So the Aussie wing section was designed to be used on the A class. It was made quite flexable but ended up being too heavy to be a good mast on the A class.

When the Hobie 18 was introduced to Australia the main 18ft class was the Stingray. To keep the Stingray ahead of the game the sail plan was expanded. This expansion involved a jib of increased size. A larger mainsail on a taller wing mast section replacing the shorter pear shaped section.

Only problem was the Aussie wing just didn't seem to be able to take the compressive loads of a 31ft mast with 2 on the wire and tended to break in strong breeses.

AHPC designed the Superwing and it went on the Stingray providing the new sail plan with very light wing mast that was strong, stiffer and reliable.

This was where I first observed the Superwing on a Stingray and I think this was the original purpose of its design.

When the Taipan was designed the first few had an AHPC version of the Aussie wing but they soon changed to the Superwing. The difference between the Superwing and the original Aussie wing is several kilograms with the heavier Aussie wing being also smaller in both minor and major axis.
Smaller, more flaxable and still the Superwing is lighter in weight.
It has been obvious from the start that the Superwing is an incredibly good mast section and looking at weight, robustness and pefofrmance, I have not seen a better aluminium mast.

Actually

Superwing = 63 mm by 150 mm (about 2.5 inch by 6 inches) has elliptical leading egde, is relatively flexible RATIO = 2.4
standard = about 85 mm by 150 mm (Like F18 masts) has a circular leading edge, is relatively stiff. RATIO =1.75

With respect to weights a standard alu mast of 8.5 mtr length on the FX-one weights about 20 kg (44 lbs) fully fitted while the same mastlength superwing on the F16's weights about 16 kg (= 35 lbs) fully fitted.

The philosophy behind the superwing mast is different from the standard mast and they need to be sailed differently. If you do that then you enter a zone of low drag high speed sailing.

As Phill says the Italians pioneered this type of mast in the 80's; the Aussies perfected it.

It is also my personal opinion that there is no better alu mast available on the market today. It is a tough puppy to beat even with carbon masts.

Wouter