Finally a carbon mast also on the Olympic Tornado!

For details see: www.tornado.org

Well, there _might_ be a new mast is a more proper way of saing it..

The class is voting over the new mast now, but it might go both ways. Remember that the class originally voted to keep the old rig instead of the new rig with double trapeze and gennaker. If ISAF had not insisted on a Tornado with larger sailarea, gennaker and double trapeze in the olympics, the Tornado would have stayed with the old rig..

What I'm missing is more information and discussion about the proposed mast. Is it faster, how much faster, are new sails needed etc..

While beeing a somewhat active Tornado sailor, I'm not sure if a carbon mast is worth the money if it doesnt make the boat significantly faster. With 180Kg on the righting line, we have no problems with righting

It will be exciting anyhow to watch the results of the ballot!

Gee, wheres are all the anti-Carbon T people?

My impression from the Marstrom sight is that top teams regularly must purchase several alu extrusions to test sail them before they find one or two they like in flex characteristics. This because consistency with alu is very hard to achieve, where as with carbon this is not a concern. Flex characteristics can be set at layup time, making masts suited to the team's individual needs (of course with the context of the class rules). Though per unti cost is higher incarbon, if you only need one versus 4 or 5 alu...you've save money.


BTW, Marstrom lists a carbon mast for tornado on their site...for over a year now in anticipation of a class change.


Mike.

MauganH17: I guess they are on some inland lakes in middle europe, still grumbling about the new rig

Marstrøm has made carbon T masts for quite some time, and he is all for the change (he is the one who submitted the proposal to the ITA). It is true that the masts differ, and that olympic teams buys different masts to find one they like.

But for the weekend warriors, and other T sailors who like to compete now and again it is a lot of money. These are the people who might vote against a carbon mast..

I would like to see the performance gains documentet before I shell out the money for a carbon mast. There has also been a quite long and heated discussion on the German T forum:
http://www.fly-tornado.de

If I were a weekend-warrior Tornado sailor, I'd be all for the carbon masts. All the "big money" teams would be snatching up the carbon masts and dumping their 4 or 5 aluminums masts at a price even I could likely afford

Give me CARBON

As a weekend warrior, I would not upgrade to a carbon stick. I also have no delusions about competing against the Olympic pro's so that is not a problem. The problem comes up a few years from now when some of my weekend competitors have carbon sticks when they turn their boats over and now they have the latest in sail shapes which are built for the carbon mast. Now the class is split at the grass roots level and participation may suffer... In an extremley tiny North America almost non existant class the effect is magnified by such an expensive changeover.

Still, If the boat is going to remain Olympic... it probably needs to continually upgrade...

You mean like the Square Top, Self-tending Jib, Spinnaker & Pole have "split" the class

I think it's a positive change...esp. since a lot of other classes are going this way (I20, F18, F20 etc).

Mike.

Yes, the rig changes did split the class. It seems that 1/2 of the boats did not upgrade to the new rig and stopped racing the boat. EG, several of the Canadian sailors took the rig change as an opportunity to retire. The Detroit fleet also seemed to melt away after the rig change as well. There was at least one boat at the Michigan Catfight which was still using the old rig in a portsmouth race.

Remember, that the only class racing on the continent is the July-Kingston Unlimited, August-CORK II, December-Tampa, January-Miami, and February-Miami OCR event. The international sailors competed in the Florida races while the Canadian races drew at most 5 boats.

BTW, The I20 was always delivered with a carbon stick in the USA. The F18’s BAN carbon sticks. My point is that nobody was forced to junk their existing rig and upgrade to a new rig. The spin upgrade and self tacker were half the cost of this mast proposal AND you really increased the boats performance for your money. The mast CAN’T be that big a deal!

Still, I don’t think it’s a big issue in the US and Canada (unless you happen to own several alu masts). Only those teams on Olympic campaigns will switch over to Carbon and they are playing a different game then you and I, so it’s not a problem sailing against them. I think the international class should consider alternatives which address this pending competitive imbalance for regions where they do have a strong weekend warrior fleets (Like Germany. (Perhaps Gold and Silver fleets) Then again… that would be a novel idea for the class … addressing the concerns of the ordinary guy!

Proud member of the Society of Ordinary Tornado Sailors
Founded at the Miami OCR 2004

Take Care
Mark

interesting.

In the UK before the upgrade, the ONLY time T's were sailed was for the selection cycle and then they would flood the market once the trials were over. Since the rig change we now have a VERY good T fleet in the UK.

I'll be buying one when my son grows up if whe wants to sail with dad....Might be a few yearsm, he is only 3 at the moment......

There are some more information about the T Carbon mast and the vote on the German class butt. web pages.

Ref: http://www.fly-tornado.de/?site=news#id89


If you dont grok german, http://babelfish.altavista.com is helpful.


Doesn't say anything about increased performance tough, only one-design considerations and safety..

I have to agree that the rig changes was a good thing for the T, but are not sold on the carbon stick yet. I would really like to see some performance comparisons between alu. masts and carbon masts first.

Dont get me wrong, if the carbon mast is consistently faster, I'm all for it!

Hello Rolf,
Carbon is not magic. A carbon mast alone is not faster than an aluminum mast. The only way that a carbon mast or any carbon part can make a sailboat faster is by reducing weight. The weight savings due to a carbon mast in the case of the Tornado class is going to be small because the aluminum Tornado mast has already had every excess ounce of weight squeezed out of it. Also to realize any weight savings due to a carbon mast in the Tornado class, the class rules, minimum all up weight, must be changed. If the minimum all up weight is not changed, it will be very difficult to find any boat speed improvement at all. Also any different material mast, especially carbon, will have a different mast bend characteristic under sailing loads. Then the boat will have to be reoptimized and new sails, diferent luff curve etc, will have to be determined. This will take a year or two to work out and many many suits of experimental sails, many dollars spent.
The Olympic Tornado is already faster than any other 20ft boat so why induce this major upheaval in mast rigging and sails for a maybe 0.001 reduction in PN?
Bill

Not so....

You will be able to design the mast bend characteristic(s) you require as the carbon can be layed up as required (eg more carbon wher fittings attach and less where there is little stress.

Bill: I was under the impression that carbon masts was better when beating into chop, as the leverage of the mast was less. I tought perhaps this was where the performance might be improved..

If you read the german class ballot information. They say that the carbon mast is neccesary to stay competitive, but dont present any empirical data for this.. I dont know any more.

They also say that it will indeed be neccesary to re-cut the mainsail. But that this is a feasible job to do on a present mainsail.

Regarding weight, this is information that is not finalized. It does not say anything about changing platform weight in the proposed rules (as far as I can se..).

Interresting times..

To Scooby and Rolf,
Scooby, I doubt there are any Tornado sailors who know how to specify a carbom mast layup schedule to acheive a desired mast bend. Carbon as we all know is very stiff. To make a carbon mast of the same section that is similiar in bend characteristics to the present Tornado aluminum mast section would require a major reduction in wall thickness. Thin mast section walls lead to crippling and local buckling problems on the compression side of the mast. Crippling and local buckling problems are stability problems associated with thin walled structers and can occurr long before the ultimate strength of the material is approached. The carbon mast wall thickness can be increased only if the section is made smaller which also makes the mast more bendy. A carbon mast section can be designed for the Tornado with similiar bend characteristics to the aluminum mast and no crippling/buckling problems but it will be in a significantly smaller mast section. This is the correct way to go from the structural and performance point of view but it has a major impact on the ONE DESIGN characteristics of the class. The politics of this question are BIG!
Rolf,
You are right in that a lighter weight mast would reduce the pitching inertia of the boat and the boat would go very slightly faster to windward in a chop. Also remember that up there with the mast are the wires and the sails and the battens. The mast itself is probably only half the "weight aloft".
A "recut" mainsail is down in area from a full size sail and I don't think many serious Tornado sailors would go for that.
Good Sailing,
Bill

As I recall, (it may have changed) isn't there a minimum tip weight of the mast.
Should the minimum tip weight be maintained? the advantage would not be all that much, if kept.
In other words, would or should the minimum tip weight of the mast be maintained?




http://www.sailing.org/classes/classrules/2004/TRNRules04.pdf
k. With the mast in the condition given in 14(i), in a horizontal position supported at the bottom
end of the extrusion and at the bottom edge of the top measurement band, the weight
measured at the top band shall be not less than:
i. 10.5kg for masts with internal jib halyards.
ii. 10.25kg for masts with external jib halyards and locking devices that are not connected to
the mast in any way.

The proposed changes to the class rules on http://www.tornado.org does not say anything about the weight (as far as I could see). So we dont know much about the weight or tip-weight of the new mast.

I guess it will be lighter, as easier righting is used as an argument for the change (and the change would be meaningless if weight was maintaned, even tough the mast would become amazingly strong).

Bill: You are probably right about the re-cut. Unless the whole front panel of the sail was replaced (most Tornado mainsails has one panel running from the bottom to the top along the luff). The outcome would anyway be uncertain and probably not competitive.
If the mast is accepted in the ballot, it will be interresting to measure the performance between the two masts..

Regarding politics, yes this is a quite hotly contended subject. One has to wonder where all the messages on the German T-forum discussing this subject is. They all disappeared last month.. Politics ?


Interresting times!

I don't sail a Tornado so what do I know. But a couple of observations.

At the highest level, the inconsistency of one aluminum mast vs another is absolutely critical. Top Tornado sailors (and sailors in other Olympic classes w/ aluminum masts) talk about "finding" their mast 1 year ahead of the Olympics. And then they have to waste countless hours / days / weeks / months of valuable practice time learning to sail with their back-ups in case the break the first one. A mast can be the difference between winning and losing. At this level repeatability matters, and carbon is nearly perfectly repeatable.

Bill -- of course all sailors don't know how to specify layups, but that is a ridiculous argument. Sailmakers and sailors specify the flex characteristics and the engineers do the layups.

I don't know if the change is good for the class or not. I am sure there are trade-offs, but lets recognize valid arguments on both sides.

There is something called hoops when looking at carbon masts.

These are rings of carbon perpendicular to the length of the mast. These do not introduce significant stiffness to the mast but do increase wallthickness that is needed to prevent various buckling modes.

This amount of hoop (some call them loops) can also be used to get the mast to satisfy the mast tip rules that may be present.

Wouter

Regarding tip weights...my Marstrom Mast (alu) came with a .5 lbs lead weight rivetted to the very top. Surprised me! How can the carbon mast be promoted as "safer" since it's lighter...yes, sure it's safer than a alu stick with even more weight stuck to the top! Wouldn't it just be easier to change the tip weight rule and get the lead off if safety was the concern? I guess the intent of the tip weight rule is to prevent extra light/thin sections which would lead to failures left right and center.

There would need to be a change to the tip weight rule for carbon, as there's much less advantage if building to alloy weights.

Another thing I found quite intriguing about all this...if accepted Marstrom will be the only allowable builder of carbon masts section for 2 years, to help them re-coup development losses. This seems quite a departure from the "any manufacturer" nature of the the class.

Mike.

Hi Stranger,
It seems strange that the variation in aluminum mast bend from mast to mast is coming into question at this time. The Tornado has been around for a long time and there has been no question about mast bend inconsistency. Even if we start the Tornado history with the Marstrom Tornado, there has been no question about variation in aluminum mast bend until recently. Recently the position has come forward to put a carbon mast on the Tornado. Has a problem with the aluminum mast been invented? The two most important parameters affecting mast bend are mast section and wall thickness. The bend in the top few feet of the mast is very small reguardless of taper because the bending moment is still small due to the short lever arm in the top few feet of the mast. The region of max mast bend occurrs in the region below the hounds and above the diamond spreader. This part of the mast is untapered. If there is variation in aluminum mast bend/flex characteristics, it is likely in the extrusion die wearing out and allowing the mast wall thickness to increase. The solution is a new extrusion die.
As far as my comment about sailors specifying the mast layup, Scooby made the comment that sailors could "design their own masts to suit their needs".
If sailors design their own masts, it will be like the story of the three bears. The first one will be too stiff. The second one will be too soft and the third one will be just right.
Good Sailing,
Bill

Bill, I think there has always been this inconsistency...see the Marstrom website for a discussion. It's just never been discussed at length because there was no solution to it other than testing many extrusions until you found one that best matched your sailing style/weight range (ie. flex characteristics). Again, this was only ever a concern at the top levels of the class, where minute performance advantages are sought after. Of course at this level, budgets are less of a concern as well.





From looking at my alloy mast under spinny loads, a lot of bending is happening above the hounds and in a leeward direction...it looks ugly-scary. This is with the older Marstrom mast (pre-2000). They have reported failures in these older sections and have increased wall thickness of the web on current extrustions. There is also an untapered option offered...but I'm not convinced this increases strength above the hounds...just the flex characteristics and obviously buoyancy after a capsize.



This is exactly what Marstrom claims as a primary cause of extrusion variation...but that is can happen quite often and leads to basically no two masts being identical in flex performance.



And once it's "just right"...they can make that same unit for all boats they buy in the future and the build can offer it to other teams on demand.

Bill-

You hit the nail on the head - the dies wear out! This is not a new problem - it is inherent in the manufacturing process.

As a result mast flex repeatablity is not up to the standards required by world class one design sailors. For weekend warriors (including me) it is fine, but I don't believe that is the issue. If the T wants to stay at the pinnacle of the sport, then there is a compelling argument for eliminating this cr_p-shoot.

How would you like spend 8 years training full time to get to the Olympics with a reasonable medal shot (that is what it takes and more natural talent than 99% of us), then you break your #1 rig on the first day of the Olympic Regatta? You would have to sail the biggest regatta of your life with a completely different mast: different numbers; different tuning; different sailing style. At this level that is a huge adjustment. And that is not to mention the cost of the extra training required to have the back-ups dialed in just in case.

And thank you Tornado for pointing out that once you get it just right then you can have it over and over and over. Yes the initial cost is higher, but the long run cost is much lower - one carbon rig (OK include a spare tube if you are really serious) vs. 3-4 rigs minimum to test for a serious Olympic campaign in some classes (and that is after you choose the section you want).

There may be good arguments for not changing the class rule -- status quo is important to keep from making boats obsolete w/o upgrades. But just because you are not an Olympic caliber sailor (maybe you are - I've never heard of you but what do I know) does not mean you shouldn't try to understand the basis for their arguments.

The good news is that all class constitutions have processes for amendments so the class gets to decide by what ever process they have in place.

OK, I don't even sail a Tornado so I will let it drop, the class will decide what it wants. But lets not put out too much bad information. Both sides have valid arguments.

IMHO
Hunt

With Tornado and Hunts.



This is simply not true.

There have been discussions within the Tornado fleet (and other fleets) for years about this. Back as far as the 80's people were talking about 'fast' masts and mast selection processes.

Bill,
I have to respectfully disagree on a couple of points. Static mast weight is not the issue. The carbon stick reduces the radius of gyration by a factor of almost 4 which reduces pitching moment of the hulls. Also, a carbon stick can be designed to exactly comply with the elastic characteristics of the aluminum mast. This is due to the orthotropic stiffness properties of the fibers. I have designed and built three carbon Tornado masts and use stock sails with no differences with the aluminum mast.

Kevin

>the dies wear out! This is not a new problem - it is inherent in the manufacturing process.<

Basically, the thickness of an aluminum extrusion can be controled by the temperature the billet is heated up to, and the pressure to ram it through the die(s), resulting in the exit speed of the new shape from the extrusion press.
As a die ages one can vary temperature and pressure to control thickness. Sometimes it ends up being a lot of scrap depending on the allowed tolerances. (we are talking plus/minus thousands of an inch)
A decade ago, it use to be more of an ART than a science to get the temperature and pressure right, maybe that has changed now.

Mike,
Once you get the mast "just right" for a lightweight team, it is too bendy for a heavy team. Once you get it stiff enough for for the big guys, it is too stiff for smaller, lighter weight, teams. There is no "just right mast" for all size teams. THAT IS THE PROBLEM! So, What is the solution? Different mast layups for different weight teams?
Where does it end? This question is really stickey!
Bill

>>I have to respectfully disagree on a couple of points. Static mast weight is not the issue. The carbon stick reduces the radius of gyration by a factor of almost 4 which reduces pitching moment of the hulls.

What exactly do you mean by that ?

"Static" mast weight (Do you have a thing called dynamic mast weight ?) DOES factor in COMPLETELY in Moment of enertia that is linked to oscillation of a platform.

You got me completely lost on your "radius of gyration" statement. Especially on how a reduction of radius REDUCES the pitching MOMENT of the hulls ?

Pitching MOVEMENT of the hulls maybe ?

Or else RESULTING radius of gyration given some reduction in mast weight ? This of course contradicts your statement of "Static weight is not an issue"

I guess there are some typo's in these statements that result in a very awkward statement otherwise you are completely off the chart with respect to dynamic of bodies.


Wouter

OK, Kevin and Sail7Seas definitely know more about the engineering than I do.

Bill- Again you got it right and again you didn't even know it!

Different weight crews want different flex characteristics -- but that is no different from today. The difference is that today they have to spend a lot of money buying masts and get lucky to find a particularly stiff or soft one.

Wouldn't it be an improvement to just get a mast / sail combo that is right for your weight? Just think how many more teams could sail the boat that way. A softer rig allows lighter crews to compete. Look at the A-cat where I am told there is a very wide range of competitive crew weights.

My wife and I sail an 18HT. We are about 40-70# lighter than a lot of the teams. We have our main cut for us which helps, but we sail with the stock rig because that is all that is available. If we were really serious (or if we had had a choice when we got the boat) we would have a softer rig (but we are strictly weekend warriors now).

The ability to engineer the flex is not necessarily bad for the weekend warriors, and it could in fact broaden the appeal of the class. And like a carbon epoxy boat, it is probably cheaper in the long run.

But you need to understand that flex characteristics of the individual spar matter to elite sailors whether aluminum cr_p-shoot or carbon repeatability. They need the right mast for their weight, and sailing style. It may not matter to you and me Bill, but it does to the top guys.

No Typos in this post, quick google on defining moment of inertia :



Definitions of moment of inertia on the Web:

The property of an object associated with its resistance to rotation.It depends on the objects mass and the distribution of mass with respect to the axis of rotation.
fuse.pha.jhu.edu/outreach/kit2/glossary.html


A physical property of a member which helps define rigidity or stiffness and is expressed in inches raised to the fourth power. It is a measure of the resistance to rotation offered by a section's geometry and size.
www.hancockjoist.com/glossary.htm


The rotational analog of mass. The sum of the products of mass and the square of the perpendicular distance to the axis of rotation of each particle in a body rotating about an axis.
unistates.com/rmt/explained/glossary/rmtglossarylmn.html


The amount of force required to spin an object.
www.bowlingfans.com/faq/glossary.shtml


– the mass of a rotating object times the square of the distance to the axis of rotation
www.mhhe.com/physsci/physical/jones/graphics/jones2001phys_s/common/glos_m.htm


A physical property of a member, which helps define strength and deflection characteristics.
www.sentinelbuildings.com/glossary.htm


the rotational analogue of mass, in units of mass*length2 (see rotational kinematics)
people.ucsc.edu/~erowland/glossary.html


Amount of force required to spin an object.
www.jayhawkbowling.com/Pro_s_Corner/Glossary/glossary_new.html


The moment of inertia of the armature is measured about the torque motor's axis of rotation. The ratio of the motor moment of inertia to the damping factor with a zero-impedance power source gives the mechanical time constant of the motor. In direct drive systems, load inertia and damping factor have to be added to the motor inertia and damping factor to determine the mechanical time constant.
www.servomag.com/reference/glossary.htm


The resistance to twisting of any golf club head when that head is impacted off-center.
www.wickedsticks.com/glossary2.htm


the tendency of a body to resist angular acceleration
www.cogsci.princeton.edu/cgi-bin/webwn

Wouter,
What I mean is that redius of gyration is the conventional name for resistance of a mass from rotating. If you take a long slender object such as a mast and reduce the weight by half it should cut this property by about 4 (or is it 8??). An aluminum T mast weighs 38 lbs and a carbon version can weigh 21 lbs. The overall radius if gytation of the entire boat is the summation of it's various parts. These can be combined by superposition just like the linear motion analogy (moments of inertia). So a carbon mast may help the boat overall by say 8% (a wild guess). The boat radius of gyration is directly related to the amount of energy it takes to move a boat through waves (reduces pitching moment and rolling moment). Does it make sense now?

And I'm in a reall antagonistic mood so please pardon my excessive use of sarcasm.

Let me see if I understand it now :

>>What I mean is that redius of gyration is the conventional name for resistance of a mass from rotating.

Actually the radius of gyration is nothing more that the "radius of gyration" it takes a little bit more to express the resistance of a spinning mass to CHANGES IN ANGULAR SPEED. Or in other words, There is no "resistance to rotating": unless you are trying to discuss the principle behind gyroscopes but that is a whole different matter.

More comments later.


>>If you take a long slender object such as a mast and reduce the weight by half it should cut this property by about 4 (or is it 8??).

It is neither. Right answer is "cut in halve". You are talking about the Moment of Enertia here which is defined as the sum or integral of the product :

lever^2 * mass (techies call this a second order moment because of the squared lever)

With a mast you must use the integral expression but this one behaves the same as the some of a given number of finite elements with a finite mass. In short the lever (or radius of gyration for that particular element or part) is squared while the mass is not. Therefor if you reduce the mass by a factor of 2 then the moment of enertia (the true expression for resisting changes in angular speed) is also reduced by 2. Reducing the lever is more efficient of course as that is a squared relationship, but that would leave you with a short mast. (And they say that reducing the mast height in the F16 class was a bad idea)

Anyways:

Somebody else claimed that a carbon mast would not be much better as their was the tip weight rule. Meaning, any mass lost must be put back on the top (in part) to arrive back at the correct tip weight.

This is a HUGE consideration as the tip weight is determined using the gravity force (1st order moment) while the performance improvements are linked to the moment of enertia (2nd order moment).

For techies under us. The mast tip weight test is a process that is dependent on the first order moment (lever * mass) while the performance is dependent on the second order moment (lever^2 * mass)

This results in the situation where the extra piece of lead used to correct tipweight results in a inferiour mast when compared to a mast that has perfectly spread out all the mass over its full length while still just satisfying the tip weight rule.

This is one of the reasons why I never understood the fact that people tried to make masts as light as possible only to have a piece of lead in the top to compensate for being underweight.

The problem is in the Lever being squared in moment of enertia.

Simple example and I will not bore you with the integral calculus:

mast - 10 mtr long
weight 10 kg (no fittings etc)
Assume all mass evenly distributed (no taper etc)
mast tip weight when layed horizontal = 5 kg

Moment of enertia = 300 kgM^2

New mast !
mast - 10 mtr long
weight 5 kg (no fittings etc)
Assume all mass evenly distributed (no taper etc)
mast tip weight when layed horizontal = 2.5 kg
To compensate for tip weight rule (as present in Tornado rules) additional 2.5 kg needed at top (= 1/2 of weigth savings)

Moment of enertia = 150 kgM^2 + that of corrector weight = 150 + 2.5*10^2 = 150 + 250 = 400 kgM^2

Making the second mast absolutely worse in performance. This new mast with corrector weight in the top compares with regard to Moment of Enertia to a mast that is overall 13,33 kg (= 77% heavier) but evenly distributed.

Tipweigths are dumb. One reason why F16 class is advicing against using them although it uses a minimum tipweight rule. It is adviced to use the excess weight in making extra loops around the mast when using carbon, making the mast more robust as well. The F16 tipweight is below what is feasable in alu so this rule will never have a problem there. Pardon me for the shameless promo for the F16 class, I just couldn't resist. However it is also an example of how the tornado class could modify their tipweight rule to keep carbon masts under control and secure the continued use of alu masts for some time.



>>An aluminum T mast weighs 38 lbs and a carbon version can weigh 21 lbs.

Well, we did some investigating on 8.5 mtr carbon F16 masts and the quotes gave about 9.35 kg for the blank = 20.6 lbs. I think your 21 lbs for the much taller and the more heavily loaded Tornado mast is a bit optimistic.

Lets continue with an estimate of 25 lbs. Ratio between new vs old = 25 / 38 = 66 % => mom enertia ratio new / old = 66 % as well when only taken on the mast and no corrector weights. Than we need to add sails 7kg's and fittings 1.5 kg halyards etc. A quick calculation ends up with a ratio of new/old = 0.85 = 85 % A long shot from the initial statement concerning the magnitude of improvements as made by you. The reduction is more like 1/6 th


>>>The overall radius if gytation of the entire boat is the summation of it's various parts.

No, that would be the summed moment of enertia.


>>These can be combined by superposition just like the linear motion analogy (moments of inertia).

Actually the lineair analogy is "Enertia" (often just called "mass") while the rotational variant is "moment of enertia" or even angular enertia in less correct fashion. You can also replace "superposition" by "adding" or "summing". Superposition is not entirely wrong in the strickt sense but suggest something more complex than is really adressed. Besides superposition is far more used in relation to waves and more complex vector calculus although even in these cases it amount to not much more then "adding"


>>So a carbon mast may help the boat overall by say 8% (a wild guess).

In what sense ? A ratio without reference framework is useless. 8 % more speed ? No way ! 8 % less moment or enertia overall ? Not likely especially not with 150 kg of crew hanging of the wires some 1.5 mtr behind the fulcrum of the rotation. In addition to that a rearbeam of 6 kg at 2 mtr and some rudder setup of 3 kg at 2.5 mtr. It is probabaly more like 4 %. 8 % less amplitude in oscillation ? That could be the case but that doesn't say much to most sailors not educated in these matters.


>>The boat radius of gyration is directly related to the amount of energy it takes to move a boat through waves (reduces pitching moment and rolling moment).


Some claim that reducing pitching inproofs performance by improving the flow over the sails that are otherwise more disrubted by constant (sometiem violent) changes in 3D. I'm not even sure that the reduction in mast related moment of enertia are even significant in the amount of energy needed to propel the boat through the water. But I guess I'm more an acceptive of the improved flow over the sails explanantion. Jury is still out on this one.


>>Does it make sense now?

Yes, thank you for explaining all this to me.

Of course I wasn't really asking for that in my last e-mail as I was asking about the proces that lead to some weird statements concerning the dynamics of finite bodies under the assumption of classical physics. But I think I understand that as well now.

Thank you,

Wouter

I think you missed the fact that I asked Kevin to explain his use of the words "Radius of Gyration".

I, of course, suggested that what he was trying to describe is actually the Moment of Enertia.

I'm personally totally unfamiliar with the "radius of gyration" definition. This could be me but then again dynamics of bodies is something that I've been tested on many years when at the university and often in the English language as a well.

Even if the "adius of gyration" exists as a definition than Kevins use of it is awkward. The second point conveyed in my post. Mostly because "pitching moment" is a force on a lever while Moment of enertia (Radius of gyration ?) is not.

And a few other things.

Regards,

Wouter

I think I got the gist of the 'gyration' theori in the first post, so I will not comment on the quite heated discussion about the proper physical non-layman terms that has bloomed in the last couple of posts.

Mark: Regarding the "Society of Ordinary Tornado Sailors", where do I join It is a shame if public perception and politic scares people off the T..


Now, if I have understood the last part of the discussion right. Going for a strict one-design carbon mast, as is proposed in the ballot, will in fact take away the possibility of the olympic campaigneers to find a mast section suitable for their sailing weight and style ?
(Warning: I'm playing a bit of devils advocate here)


To all the non-Tornado sailors who has given their opinion, please continue to do so! In my opinion, all information is of the good, and different views on an issue only gives a richer base of information to make a decicion on..

Hi Rolf,
One of the smartest rules I have ever seen dealing with mast bend and how to make it vary with crew weight was in the International Contender Class. The mast extrusion can be fixed, one design. The location of the hounds can be varied within limits. This way the lighter weight sailors, for example, rigged their masts with a lower hounds position which resulted in a greater bending moment being applied to the mast for a given mainsheet tension. The larger sailors rigged their masts with a higher hounds position which reduces the lever arm to the mast tip. The shorter lever arm reduces the bending moment imposed on the mast for a given mainsheet tension. Since the heavier sailors must control their sails with more mainsheet tension, the higher hounds position keeps the mast from overbending and flattening their sail prematurely.
One might suggest that the heavier weight sailors just start out with a fuller sail and live with more mast bend. This is a compromise because it forces the heavier weight sailors to use a sail that is too full in light winds.
Bob Miller was a smart man.
Bill

Wouter,
The radius of gyration is also called the radius of inertia. It is a fictitous radius that when squared and multiplied by the mass of a body produces the same moment of inertia as acquired by integrating the elements of a body times the radius squared to each element over the entire length of the body from some reference axis.
(Radius of Gyration = Moment of Inertia/mass) The comment about the carbon mast having 1/4th the radius of gyration of an aluminum mast can only be correct if the carbon mast has very heavy elements near its base and very lightweight elements near its tip. I doubt that this the case.
Bill

Bill,

Thanks for confirming that to me.

So in basis the Radius of gyration will not change at all when making a mast lighter UNLESS the relative distribution of the mass is changed as well.

Yep, got that

Wouter

Wouter,

Exactly. Note that the radius of gyration can be reduced simply adding weight to the mast foot, but this doesn't improve performance. Add more weight and the radius gets smaller and the boat slower.

Something like this could happen if the new rules maintained the minimum mast weight unchanged but eliminated the mast tip minimum weight.

I wouldn't expect them to do that (I hope so) because it would be weird to use new carbon masts with lead weights in the mast foot... The gyration radius would be small, but reducing the minimum mast weight and tip weight obviously make a lot more sense.

Regards,

Mike Grandfield's letter to the US Fleet
followed by Roland Gabler's point of view.

Dear All,



Although I have great respect for Roland, I believe that he has NOT given you good advice regarding the carbon mast ballot proposal.



Here are the reasons why:

1). THE PROBLEMS OF THE FINN SAILORS HAVE NOTHING TO DO WITH THE CARBON MAST PROPOSAL IN FRONT OF TORNADO SAILORS.

- The Tornado ballot proposal includes both pricing and price guarantees. The guaranteed price is 40-50% more than the current Marstrom aluminium mast.

- The Finn mast is not a strict one-design mast. It is customized for each sailor.

- The Tornado carbon mast is a strict one-design, with very precise tolerances; and the design will be transferred to ISAF to protect the class and ensure that other builders can be licensed.

- The problems of Finn mast breakage are not relevant; the proposed Tornado carbon mast was designed for strength and durability, and Marstrom has built over 3000 carbon masts.



2). The aluminium masts have never been equal for all TORNADO sailors; and by next year no one WILL believe that they are TRULY one-design.

- There are 5 flexibility groupings of the current Marstrom masts. Only a few top sailors find really good masts, most of the fleet gets average masts.

- Most current Marstrom masts bend differently to port than to starboard. How many sailors have noticed that they point better on one tack than the other?



- Today, there are commercially available aluminium masts from Marstrom. Hobie, Nacra, and soon from Swiss Carbon; and there is a privately developed mast that was designed the UK with funds from the RYA - this mast has been used at Hyeres and SPA, but it is not commercially available.

- There are at least 2 additional mast designs that could be built if we stay with aluminium.



- So, we will have between 5-7 different aluminium masts. Each one has a different die and different cross-section; BUT each of these measures in as a LEGAL Tornado mast.

- Is that ONE DESIGN? NO!



- If any of the new designs are better than the current Marstrom aluminium mast, then EVERYONE will have to buy a new mast.

- If the RYA mast is the best, but not commercially available, then EVERYONE will complain that it isn’t fair and could easily spend a year or more trying to develop a mast that is competitive.

- If we keep the aluminium mast, we could easily become LESS one-design than ever before.



- There is no price protection with aluminium. A higher performance mast could easily be as expensive as a carbon mast.

- ONLY FULLY FUNDED TEAMS WILL BE ABLE TO AFFORD THE COST OF TESTING NEW ALUMINIUM MASTS AND THE SAILS THAT MATCH THEM.



3). THE REASONS TO CONSIDER THE CARBON MAST ARE NOT “LIGHTER WEIGHT” or “HIGHER PERFORMANCE”

- The Marstrom aluminium mast is not strong enough; Marstrom is selling over 3 times as many masts as new boats! The fleet has spent over ½ MILLION EUROS (Before VAT!) on spare and replacement aluminium masts since the new rig was introduced.

- The Marstrom aluminium Masts are not equal in performance; by next year there will be at least 5 different aluminium masts to choose from.



- The reasons to choose between aluminium and carbon are:

o Strength

o Safety

o Equal Performance

o No advantage to teams with bigger budgets



4). I DON’T WANT TO SPEND MONEY ON A NEW MAST; I STILL HAVEN’T BROKEN THE ONE I BOUGHT IN 1998.

- But, by next year there will be a better carbon mast or a better aluminium mast.

- In 2005, we will all have to consider buying a new mast to remain competitive.



- I believe that the carbon mast ballot item is a very good proposal and the best way to provide a level playing field.

- I’d be excited to sail with a new carbon mast; but I’d be frustrated and angry to have to buy a new aluminium mast instead.



For many years the Tornado fleet has been protected because all of the boats and masts came from Marstrom. THAT TIME IS OVER. The real choice is a one-design carbon mast or a new “arms race” to build a better aluminium mast. It is unrealistic to think that nothing will change.



Clearly, the RYA has already committed to the new aluminium mast effort. SOME OF YOU WILL PROBABLY RACE WITH IT OR AGAINST IT IN ATHENS.



The carbon mast ballot item is your opportunity to choose the future you want for the class. I hope you choose wisely.



Regards,

Michael



-----Original Message-----
From: Roland Gäbler [mailto:roland.gaebler@sport.tdcadsl.dk]
Sent: Wednesday, July 14, 2004 7:50 AM
To: [email]yann.guichard@wanadoo.fr;[/email] Hugh Styles; Hugo Rocha; [email]iorpas@yahoo.gr;[/email] Jim Young; John Forbes; John Lovell USA 808; [email]Jpolgar@aol.com;[/email] Jürgen Jentsch; Kristof Koch; [email]mail@sailcenter.se;[/email] Marström AB; [email]mgrandfield@sailingwind.com;[/email] Mitch Booth; Niko Mittelmeier; [email]obackes@aol.com;[/email] Nuno Barreto; [email]p.wetzig@gmx.de;[/email] P. Egger; Patricia Kirschner Ross; Patricia Tornado; Patrick Egger; Philip Wetzig; [email]pres@tornado.org;[/email] Ralph Mittelmeier; [email]ramirami@t-online.de;[/email] Sail Center Per Wearn; Sebastian Moser; [email]sec@tornado.org;[/email] slange; [email]tornado@topica.com;[/email] Wolfgang Heinemann; Will, Fabian; [email]will.howden@virgin.net;[/email] [email]xavier-revil@wanadoo.fr;[/email] Aaron McIntosh; Aaron McIntosh; Guenter Moertl; [email]GunnarStruckmann@aol.com;[/email] [email]funinthesun@juno.com;[/email] Ullman Sails - GZ S.r.l.
Cc: Jürgen Tiemann; Darren Bundock; BSG Sports
Subject: Carbon Mast
Importance: High



Dear Tornado Friends,



just some days ago I had some nice talking with some Finn Sailors in Athen about their change to the carbon mast some years ago.



- 4-6 times more expensive (and the mastbuilders said before it will cost just the half more) ha, ha, ha, ha.....

- A carbon Finn Mast cost 2.800-3.500.- euros now !!!! ask your national finnsailor

- A Aluminuim Mast was 700-800.- euros !!!!



How much we must pay to make our boat 8 KG ligther? My Finn Friend sayed, he can finance a new house with all the money he spend in carbon masts last years. Hy guys, wake up................



Security. Safe Sailing? We are the Formula one of sailing. Who wants to go save with this boat. Just not go out when it blows 30knots plus offshore.



Do you think if you open to much the sheet under spinnacker what the carbon mast will not brake? The Finnclass broke more mast than ever in the last years!



Each Finnsailor has 3-6 Mast plus 3-6 light cloth sails. Also forget the cubenfibre sails, they are shrinking.



Instead of getting more milliseconds of speed, we should not forget the think about the youth. How they should finance the new masts? Plus Spinnackers, Plus Cuben Fibre Sails?????????



Do you think only Sail Center of Sweden will make the mast? Many others will come.



I can easy make each mast different. What a nice and expensive mixture???



One Question: How much money you spend in Spinnacker last 3 years? Worth one Car? Ok, we have max fun with our spinnacker. Yes, yes, yes we enjoy........But do we get some much fun-factor with the carbon mast?



Lets concentrate to get back on our One-Design and Olympic Idea.



If you want go faster, buy the M20



I donnot want to talk about the carbon mast. I just wrote my way. Please do not answer this mail. Just answer the ballot and SAIL FOR FUN



See you in Athen. Cheers,



Rolando

There's that "one-design" phrase being misused again.

Well you comment immediately proofs that Radius of Gyration is bad measure then.

One can reduce the radius of gyration by the way you decrease and end up with worse performance. One can increase radius of gyration adn also end up with worse performance. This makes this measure a bad to optimize upon. Better to use the real thing : the total moment of enertia.

>>Something like this could happen if the new rules maintained the minimum mast weight unchanged but eliminated the mast tip minimum weight.

It sure could but why would you want to rule against that ? You end up with a worse performaning bad so this will selfregulated itself into oblivion. No class rule needed for that.

Wouter

I still see some misunderstanding in the posts and since engineering jargon confuses people and is not appropriate for the forum I feel obligated to do a better job explaining in terms of concept (no fancy words). This can be done by comparing two imaginary boats that are identical in their shape, volumes and rig geometry. Boat A is the stock Marstrom Tornado built of S-glass and aluminum spars. Boat B is a tornado made out of imaginary stuff that is infinately strong and stiff so it dosen't weigh anything. Say we want to correct boat B so it can race fairly with boat A. One approach might be to fit a single large weight correction on the centerline just aft the beam of boat B and a few inches above the designed waterline. So now boat A and B float on the same waterline and if we pull them through still water they have the same resistance. But are they fairly handicapped? Next boat A is sailed against boat B in a seaway and boat B beats the crap out of boat A. Why? What's the difference? Boat B has smaller radius of gyration with respect to it's three rotational axes: pitch, roll, and yaw (this is the technically correct term in continuum mechanics in this country). The concept here is fundamental to boat design. It is expressed by the sailors intuition to keep weight out of the ends and as low as possible.

Kevin

Mark,
I agree with the points you make. Another thing to consider is that the variability between carbon tubes in terms of weight and stiffness can be quite a bit less than the current alumunum hardware. This is assuming you standardize on one builder using identical prepreg material and layup schedule. Variation in the weights of the Marstrom prepreg platsorms run in the neighboorhood of several ounces for a 284 pound weight. So, we are talking in the nieghborhood of .1% weight variation. This is also the type of results obtained with aerospace composite parts. I suspect this is less than the current tolerance on the aluminum sticks. The goal is to to make sticks with enough similarity that no one has an incentive to shop for multiple masts optimized for crew or wearhet conditions. To do this with composite tubes you almost have to commit to a single builder because even if material an tooling are specified the layup (individual ply orientations) can be manipulated to produce tubes with a wide range pf properties even though they weigh and look the same. Thus, you would also have to specify and control layup schedule. Not a hard thing with one builder but becomes more difficult with multiple builders.

Kevin

Kevin: In the ballot proposal, they do mention some stringent stiffness measurement procedures to make sure the mast has the proper one-design virtues. I guess masts not buildt to the spec. will not be accepted at measurement before competitions.

Kevin,

The best parameter to compare a normal boat and one with less weigth in the extremities is the moment of inertia (around each axis).

Equal boats or masts have the same weight, the same moments of inertia and the same "stiffness". It is simpler then using radius of gyration as a parameter, which only confuses things.

If I understood correctly, the idea is to have a one design mast in order to reduce its price and the work done to tune the rigging. The downside is that it will create an optimum crew weight in the Tornado (for each wind force) and the sails will be more complicated to customize for each crew.

Cheers,

Problem with radius of gyration is as follows :

Lets take your Boat A = the stock Marstrom Tornado built of S-glass and aluminum spars.

Keep your boat B is a tornado made out of imaginary stuff that is infinately strong and stiff so it dosen't weigh anything. This one has a reduced radius of gyration and performs better.

Then we introduce boat C this one is the same as boat B but has a given weight strapped to it dolphin striker pin. As the radius of gyration is defined as "Moment enertia / totall mass" we can say that this boat has a reduced radius of gyration as well ! But we all know this boat to be a worse performer. So the net result is one where the radius of gyration is reduced and the boat performs worse.

In the imginairy case we could strap an very large weight (infinite even) to the pin and arrive at the same radius of gyration as boat B. Naturrally this boat C will have far war performance than boat B because it will be on the bottom of the lake ar form a black hole (different topic)

Point of this example is that a similar reduction in radius of gyration can be had by both increasing and decreasing weight; both leading to better performing and worse performing boats. Radius of Gyration, although technical useable, is therefor a traiterius principle to use.

Moment of enertia calculations don't have this problem and will assign a higher value to boat C no matter what the added weight.

Wouter

Hi Jake,
You bring up an interesting question, "what is one design"?
Is it exactly identical equipment for all sailors within a given class? If so, how do we handle the fact that "people are not one design"? Heavier people make the boat have more drag going through the water; lighter weight people have an advantage with less hull drag. When the wind blows hard, say 15 knots and up, the heavier people have an advantage because they can generate more righting moment and therefore have more sail thrust. Even enough more sail thrust to more than offset their greater hull drag. We all know from experience that lighter weight teams have a speed advantage in light winds and heavy weight teams have a speed advantage in strong winds. Putting non one design people on our class boats has shot a big hole in our one design class objective of having all competitors having the same max boat speed potential on all points of sail in all wind conditions. How do we fix this? What is the best way, the most fair way, to compensate for this inequality?
Let the ideas flow....
Bill

Bill,

In response to the argument that the Tornado class should allow other manufacturers to produce Tornado parts, I was actually trying to point out the difference in the phrases "one design" as defined in the spirit of the Tornado rules and "one manufacturer" that everyone now seems to consider the Tornado. The very context of the phrases indicates that while a "one manufacturer" class can also be a "one design" class, a "one design" class doesn't neccessarily have to be "one manufacturer". I don't interpret any intention for the Tornado to be a "one manufacturer" in the class rules.

However, I agree with you (did I say that?)

Louis, Wouter,
I follow what you are saying. We are trying to describe the same effect but are tangled up in terminology. You have raised enough question for me to go back and check. I have always been under the impression thet RG is defined as mass X moment arm. But from the point of view of the forum, probably nobody else is interested in this and next time I will avoid using any technical words - we all should.

Jake,
What about this "one design problem". How do we compensate for the fact that sailors, people, are not one design and this by itself has a large affect on the outcome of sailboat races???
There seems to be two schemes in place today.
1. One is the factory class where only factory parts are legal. All other parts are illegal. This is a money driven idea and does not inhance one design sailboat racing but is used as an excuse/example of "one design sailboat racing".
2. Another plan is to have all identical boats, masts, etc except for the sails. In this plan all sails are the same size/area but the camber distribution, the shape in the sail, differs. There are full cut sails and medium draft sails and flatter cut sails. The heavier weight teams use the full cut sails because with their greater weight, they are going to bend the one design mast more and therefore their sail must have more luff round. The medium/average weight teams use the medium cut sails and the light weight teams use the flatter cut sails. This plan has shown in many different one design classes over several years that it leads to tighter competition than giving all sailors the same cut of sail.
Let's look at Olympic class sailing and see how "the best", the ultimate sailing classes/contests, do it. If there is a more correct way to handle this problem, surely it is done most correctly in the Olympic sailing contest. When I check on the Star and Soling and Yingling and Tornado and Finn and other Olympic classes, I find that the Laser is the only class requires all sailors to use the same cut of sail. All other classes allow variations in sail cut within some max limits for that class. Who is right? Other large one design classes in the US such as Snipe, Thistle, Lightning, J24, etc all allow variations in sail cut within max sail measurements for that class.
Both of these schemes cannot be more correct. One of them has to be more fair and the other less fair, less correct, in compensating for variations in sailors weight.
We can require the light weight teams to add weight up to the average teams weight and this fixes the light weight teams advantage in light winds. How do we help the light weight team out in heavy weather sailing? To take away their light wind advantage and not fix their heavy weather disadvantage is not fair.
What do we do to get it right???
Bill

Kevin,
The radius of gyration squared equals the moment of inertia divided by the mass. RG**2 = I/m. Therefore I = RG**2 x m. RG is a radius at which if all the mass was concentrated there, it would have the same inertia as arrived at by integrating (r**2dm)of the body over its entier length.
Bill

Kevin,
Now you are really confusing me. You are saying that the variation in Tornado platform weight is several ounces out of 284 pounds or about 0.1%, one tenth of one percent. That platform is made up of two composite hulls, some fixed rigging and two aluminum beams 10ft long each. These aluminum beams are extrusions. They seem to be very consistent in weight and therefore other properties. Why is it that the extruded beams can be so consistent and yet the extruded masts are out of control??? The company that manufacturers the carbon mast also manufacturers the aluminum mast. The only company that manufacturers the carbon Tornado mast is the company that is partitioning the class officials to change to the carbon mast. Is the fox in the chicken coop??? Other classes have no problem extruding aluminum masts by the hundreds that are identical. If the Tornado class has a problem doing this, maybe they need a new aluminum extruder with better quality control.
There is one other important point relative to the carbon mast. Carbon sands very very easy, cuts fast. Sandpaper cuts carbon like crazy. What is to keep a carbon mast owner from sanding his mast to make it bend to fit his weight? If he does is this legal or illegal???
Bill

mastrom quality control allows him to make

285 lbs = 129.105 kg platform within a margin of no more than 0.1% = 0.129 kg = 129 gram or the equivalent of 1 and a halve ronston smart ratchet blocks (the small kind) ? The pre carbo ratchmatic Harken ratchets were 142 grams per single block.

I think this to be a really strong claim. Halve of a plastic coffee cup with resin weights the same 120 grams if not more.

If you spread that out of two hulls of about 15 - 17 sq.mtr. overall surface you would add a film of only 42 micrometers = 1/600 of an inch.

And the funny part is that people can easily differ by some 5-10 kg's per person or 50 - 100 times the margin that Mastrom gives his boats. What is the use ? That is a whole lot of accuracy for nothing.

Better still is one of the sailors decided to take a cup of coffee for the race, as Mitch did at the 2004 F18 worlds, than that crew would allready by 2 times the marstrom margin overweight. No wonder Mitch finished 15th in that race. (joke). A pair of sunglasses weight 100 grams or more

Wouter

Bill: I dont know about the quality control on the Marstrøm masts, but generally Marstrøm has _very_ good quality control. As I know Gøran, he has done his best to get mast extrusions with identical physical properties. Gøran seems to be doing quite good business supplying alu. masts. 500K EUR is real money spent on masts since the new rig.

Regarding sanding the proposed carbon mast: There are a whole new regime of measurements to be taken with regards to stiffness. These rules are designed to weed out masts with differen properties than the one design mast.

As Mr. Granfield wrote, the RYA has developed a propetiary alu mast that measures in under the current rule. This mast is used by the very succesful british team. He wrote quite a lot about why he was not happy to spend money buying a new alu. mast.

Interresting times...

Hi Rolf,
I know Marstrom tries to do his very best and his very best is very good. That is why there is only one Tornado manufacturer now. He is not in the extrusion business. Some company extrudes masts for him. Marstrom is not in control of the mast extrusion quality although he can reject masts upon inspection.
Aluminum shapes, tubes,angles,flat bar,T bar, all kinds of special shapes are extruded all around the world and done so very consistently. The aluminum Tornado mast should be no exception.
I remember from my SC days, initially we had a problem breaking the mast extrusion die at the part that formed the sailtrack. A diemaker advised a slight change in the internal shape of the track and no more breakage of dies. There is a little art in the die making and extrusion business/process.
I remember reading not too long ago about a new aluminum alloy that is superior to the 6061T-6 aluminum alloy commonly used for sailboat masts. It is both stronger and lighter in weight. It is used in the commercial aircraft business, airliners, and is making a significant increase in aircraft range. If the Tornado class is going to make a change, this new alloy should be investigated for all their extrusions.
The situation of the Finn class carbon masts is scary. I'm sure before they started building carbon masts, the situation was thoroughly investigated and the conclusion was that the carbon mast was the best answer. Now the class has a big mess on its hands. I'm sorry to learn this. It hurts the Finn class and Olympic sailing.
Bill

Well, I dusted off the textbooks and the right term for what I have been trying to express is "polar moment of inertia". In my case I confused the term with RG. The polar moment is a different mathematical expression from what is commonly called "moment of inertia". So, we are all guilty of using less than accurate terminology.
The assertion that Tornado hulls have very little weight variation came from a 1996 article in Cat Sailor magazine that was describing preparation for the Olympics in Savannah. The measurer stated he was surprised that weights of the Marstrom boats only varied a few ounces. But, if the measurer's claim is still suspect, there is data from many other composites applications. For instance, carbon helicopter blades completely out perform aluminum and have better tolerances on both weight and stiffness.
It would not be practical to alter a carbon stick by sanding it. You could not remove material with enough uniformity to achieve any desired end result. Whatever you ended up with would be sheer luck. If someone really wanted to cheat, it would be much more feasible to chemically mill an aluminum tube than sand a carbon one.
There is a potential problem with measuring stiffness as a way to ensure consistency. This is because even if stiffness of both the major and minor dimensions were measured, games can be played by altering ply lay up alter stiffnesses in other orientations. What makes the unidirectional fiber such a flexible material to design with becomes a liability when trying to assure exact properties from one builder to another. To remove variation in composite sticks it drives you towards a single builder. I reserve judgement whether this is good or bad. It's certainly not in the spirit of the original Tornado rules but then the current aims of the class are different.

Well,

It is also known.

I(polar) = I(axis 1) + I(axis 2)

So I(polar) is nothing more than the sum of I(axis 1) + I(axis 2) where the two axis are perpendicular.

Of course with a mast the I(y-axis) is very small compared to I(x-axis) ; a ratio of 1 to 30,000. So it is very convenient approximate masts (the thing we wre initially talking about) by calculating only I-(x-axis). In short Ipolar of the mast is very closely approximated by I(x-axis) alone.

In basis you are right however. I(polar) is the thing you need to do math on rotations dealing with the whole platform. However for dive decelleration calculations you'll need I(x-axis) again and not I(polar).

Things are getting easier by the post aren't they.

As Radius of Gyration was not incorrect in the strickt sense but a it is a confusing expression to use.

may point was however than reducing mast weight by a factor of 2 reduces the polar moment of the mast by 2.0000333 when looking at rotational oscillations. For decelleration dives only one of the normal moment of enertias is involved and this is reduced by 2. This is only for the mast and the total of I(polar) is determined by many components INCLUDING for example the crew itself especially when far away from the main beam. The overall net effect of reducing the weight of the mast by a factor of 2 can have a net result of about 5-15 % overall depending on several factors

I think ths wraps it up nicely for all of us.

Wouter

It seems the construction/manufacturing tolerance is why the sailors have found masts with different stiffnesses. Skiffness of the mast is a function of dimensional properties and physical properties.

Aluminum dimensional properties will vary http://www.almag.com/tolerances.htm
Yes, you can reject masts, but at what cost?
In the manufacturing world no one likes their product to be rejected.
What dimensional tolerance are the sailors willing to pay for?

For aluminum physical properties, to my expensive/suprise I have found the Modulus of Elasticity (Young's Modulus) for one sample of aluminum alloy 6063-T6 to be 9 msi, when it is supposed to be 10 msi (10 percent difference) How is this possible?

For carbon dimension properties what if someone misses a layup?
How are dimensional properties of carbon mast going to be checked?

For carbon YM I have found it can vary from 30 msi to 100 msi.
Someone could accidentally ship 40 msi carbon fibre.
How is carbon YM going to be monitored?


Rather than the TRADITIONAL quality control of the dimensional and physical properties of each mast to decide weather to accept or reject it; use the RESULTS OF the above properties AND field measure the deflection/stiffness by placing a weight. (I don't think to many extuders would be happy doing this, but you get what you pay for)
Some type of mast rating system could be used; ie, this could be based upon tip or midspan deflection in both major and minor axis.
Again, measuring the RESULTS OF the manufacturing process, after all the sailors are interested in the results/stiffness not the thickness or YM. (provided of course is it properly designed for bending and shear)
The resulting measure of mast stiffness could then be catalogued to crew weight (but how many catagories is another thread)

The most important thing is to have a sail and mast that make a good combo.

Most differences between masts, I'm told, can be taken out of the equation by measuring your mast bend characteristics and order a mainsail to fit your mast.

Ordering custom sails for a given mast flexing is standard stuff with many sailmakers. The testing itself takes two saw horse a bucket able to hold 20 litres of water and about 2-3 hours of your time.

Also I would like to add that an oddset need not be the same over the full length of the mast. Meaning inconsistancies can wave over the full length of the mast and average themselfs out a bit as a result.

I personnally think it to be cheaper if the class collects the batch of produced mast and puts in a day of measuring each mast and marking each mast with the basic characteristic. The sailors can then request their perferred mast section and only pay for one mast. This is always inmensely cheaper than everybody getting carbon and due to the normal distribuation of crew weigths and sailing style all masts will be sold. Remember that the off sets of the mast themselfs , as a result of a natural proces, has a normal distribution as well. I think people familiar with Random variables ar familiar with the term "normal distribution"

At least it is this approach that I think I will propose in my class when the differences between mast proof to be to great to be acceptable. We are already sharing mast stocks between builders.

I think it would be a small feature for either the Tornado class or the marstrom yard to perform this trick as well.

Would leave everybody happy and keep cost down. That is unless other reason lead to the decision to go for carbon.

Wouter

Some of the reasons for changing to carbon mast....
* Lighter mast, the carbon mast will be around 15 kg compared to the alu mast that is 25 kg. This makes the boat SAFER! This is VERY interesting for non proffesional sailors so they can right the boat themselves.
* Stiffer mast. The current alu mast has an s-shape instead of a normal bend wich makes it very difficult to get a proper sail shape.
* Reduce risk of mast breakage. The aluminum mast is very close to collapsing, one wrong move and you loose it!

/hakan

>>... The current alu mast has an s-shape instead of a normal bend wich makes it very difficult to get a proper sail shape


The carbon mast will have a S-shaped bend in it while sailing as well. This is the result of the way the stays are rigged to the masts on the cats. Carbon or not Carbon is of no consequence.

Wouter

Kevin,
Are you still building carbon boats? email me at c_boyd99@yahoo.com I have a project I want to chat with you about.
Thanks

ref: http://www.tornado.org/html/news_article.asp?ArticleID=41

The carbon mast was accepted by the class, with 71% of the votes in favor of the mast. 187 votes was recieved.


Time to save some money and order a mast from Mr. Marstrøm..

Hello Hakan,
There is one very important point you did not mention. 1. The price of the Tornado just went up $5,000 plus US dallars. The boat is now a 30,000 dollar boat instead of a 25,000 dollar boat.
2. The weight of the carbon mast will not be 10kg lighter than the aluminum mast. Maybe a 5kg reduction is possible. If the new carbon mast is made to the same section as the present aluminum mast, it will be very very stiff. This means a new mainsail luff curve is required with much less curvature will have to be developed for the carbon mast and here goes the $$$$, dollars, running away again. Also the stiff carbon mast with reduced bend will make sails less versitile. Now the Tornado sailors will need light wind sails, medium wind sails and strong wind sails; the $$$$, dollars run away again.
3. The reason masts of any material bend in an S shape with spinnaker up is that the spinnaker hounds is too high above the main hounds, too much cantilever. Lower the spinnaker hounds is one solution. Another very simple and inexpensive solution is "back stays". Then you might as well go masthead with the spinnaker.
4. The present aluminum Tornado mast does have very little structural margin with the spinnaker and double trapeze. This is no surprise. A slightly larger aluminum mast section would be one answer. The cost of the new extrusion die equals the cost of one carbon mast.
Summary: What it comes down to is the Tornado class wants a carbon mast no matter what. To have it bend properly and have a thick enough wall so that the new mast does not have local buckling problems, the carbon mast section MUST BE SMALLER with a thicker wall. Then the class can have a mast that is bendy as the present aluminum mast and is tough at the same time with a reasonable wall thickness. The new smaller section carbon mast just made several hundred Tornado masts, maybe thousands, of aluminum Tornado masts not competitive. For a class to go from an aluminum mast to a carbon mast is one tough question. It has major impacts on many facets about the boat. It is not nearly as simple as "substitute carbon for aluminum and save 40% in mast weight and go for it".
Good Luck,
Bill

This i'm sure is just barely relevant to the subject, but as someone who has just become part of a partnership to start racing in the olympic class with an old, albiet still new in packaging tornado, this is kinda dismaying, because when this becomes the standard we will not be able to afford the change. The price of entering this game is daunting enough already, how much can the cost go up before you virtually eliminate new sailors entering your class?

Cost of the carbon mast from Marstrom will be held at 2860 EURO (~$3500 USD) with all fittings. Cost of an alloy mast with all fittings is nearly 1700 EUR0 (~$2100 USD)...a diff of $1400...where is the $5000 increase coming from? Whole boat is ~$22,000 USD...about a 6% price change for a carbon mast rig.

Minimum weight to be 15 kg...end weight to be set prior to final production by Marstrom.

Why do you say the section thickness will be the same as alloy, thus making a very stiff stick? I see no mention of it in the proposal:

Rule Changes

Mike.

Josh,

the whole point is to stop people buy specially designed masts of alloy that are of limited availability. This creates an unfair competition. Also, the fact the top teams spend big bucks on numerous alloy section masts until they find a few they like (extrusion inconsistency), makes it quite expensive to be competitive.

Finally, equipment costs of an olympic campaign are a drop in the bucket with respect to the costs of training/travelling globally for at least a few years. Greg Scace, a USA campaigner until recently, told me his teams budget two years ago was $100,000 USD for ONE YEAR!!!...and that would ramp up significantly the year prior to the games. His main sponsor (and employer) got caught in the dot-com burst and dropped their committment. His olympic dreams died that day.

OK so maybe i misunderstood, i was under the impression that everyone was already limited to alluminum, because of the talk of the carbon fiber being "accepted". So is it more accurate to say that before mast was limmited only by leagnth, and this new rule limits the material as well? Sorry for being mostly ignorant, but sometimes I really have trouble getting past the price tags. To me $1400 is ALOT. But of course I have no sponsors, and by myself i probably never will.

I have an 8 year old boat with one of the original pre spin masts.... I don't double trap with more then 380 lbs on the boat because I fear I will break it going up wind....(Advice of Darren Bundock) Down Wind.... I blow rotation to allow the mast to rotate to 90 to keep it together in a breeze.

When I break it.... I would much rather put a carbon mast on the boat and get a (new to me).. slightly used sail from someone on a campaign. The technology will be superior to anything else on the market.

If I sell the boat to a cruiser... an aluminum stick will be just fine for them as well.

The Olympic guys want a carbon mast for two reasons:reproducibility and cost control based on the class president's letter.

Reproducibility... They seem to collect sticks to find the proper one for them.....They believe that the carbon masts will be far more reproducible and so cheaper in the long run. Cost Control.... Well funded campaigns (the Brits) have a mast program on going so the cost of playing just went up enormously.

With respect to a the cost of the boat... an I20 with carbon mast is close to 16K.... Is a Marstrom worth a 5 or 6 K premium?? ... ABSOLUTELY... the boat is bullet proof for 10 years and holds it value longer.

With respect to a campaign... the cost of the boat is trivial compared to the cash needed for sails, travel regattas and coaching.

Take Care
Mark

Clarification...only Alu Alloy masts were allowed until today. Now carbon is permitted, but only masts from recognized builders. Marstrom will be the only recognized builder for two years (at least!) to allow them to recoup tooling/development costs. Price is to be held at the 2800 Euro amount unless carbon costs rise significantly.

Sad fact is, $1400 is peanuts to a serious team...that's the reality of competing at this level. Good news is there will be lots of very good alloy tornado masts flooding the used market in the coming months...plenty to keep the average joe happy for years to come. But no new extrusions will be made.

How soon will this effect things realistically, I know my freind, I guess its ok to call him my teamate now, ordered a carbon mast from europe lsat year sometime, and is still waiting to recieve it. I know he's not the only one, Roy Seaman ordered the same mast at the same time and is also still waiting for his. Will this be the case with these as well?

Hi Mike,
It looks like Marstrom is doing everything he can to get the carbon mast on the Tornado. Marstrom brought the point up in the first place. Marstrom is the only manufacturer of a carbon mast for the Tornado. Marstrom's web site talks about the problems with the aluminum mast. Marstrom is initially pricing the carbon Tornado mast well below a normal price based on mast size. "He is working the problem".
My comment on mast section: Mast section or any beam/tube section is described by its outer dimensions. In the case of the mast we would be talking about the major axis length and the minor axis length. When I say same mast section, I am saying same mast outside shape. If we want to talk about mast stiffness, we talk in terms of moment of inertia which brings wall thickness into the discussion.
Carbon fiber is ten times as stiff as aluminum. Therefore if we build a carbon mast and we want it to have the same mast bend stiffness/softness as an aluminum mast, we will have to go down in mast section, shorter major axis and shorter minor axis. Reducing wall thickness to compensate for a 10 times stiffer material is not an option here. The resulting very thin wall thickness would cripple/buckle under normal mast loads. A smaller mast section in carbon with a thicker wall thickness would solve the strength/stiffness trade off study for the Tornado class. The only problem is that the Carbon mast will make obsolete hundreds of aluminum Tornado masts.
Bill

I will reserve my opinion until I see a new Tornado Carbon mast in action.

I have been playing with a shortened Marstrom's A-Class carbon mast with a cut down Tornado sail for a couple months so what I have learned may be of some use.

The mast is light and stiff. It's about the same weight as a Laser mast

It is partially foam core. The foam area and the carbon thickness seems to vary along the length.

The mast is stiff but more flexible above the hounds.

You set the mast curve with diamond wire tension. I can set mine to match the luff curve in a Tornado sail. I have heard some scary numbers like 900-1200 lbs from some A-catter's. I am using ~300-500 pounds.

For the first couple of weeks, steel wire stretches a lot compared to the amount of adjustment. For a Tornado, I might go with rod.

The Diamond wire tension is controlled by one bolt at the base of the mast. It's kind of wild to set everything up on a windless day and then make the hollow spot in the sail appear and disappear by playing with one bolt. We are not talking about a lot of adjustment, 2 turns or less. As I write this, I'm thinking "Maybe I should mark the bolthead to see if it's backing off".

Compared to a tapered Tornado mast, the carbon mast is a lot less automatic. It's not going to flex and adjust the sail shape for you. The mast will hold the shape you set and expects you to adjust the shape as needed. It's like an extreme version of the pre-bent Tornado rig.

On my setup, over sheeting has turned out to be a no-no. Sheet in hard on a puff and I slow down.

Now, if they would just fit a captive ball base to the Marstrom Tornado. (I can use Marstrom's base, I just don't like having an adventure every time the mast goes up or down.)

Interesting thread, but I think we`re missing the point here with respect to the reason for the change.
From what I`ve read here, the main reason seems to be to control costs at the cutting edge of the sport, where only 1% of the competitors play, and are paid to do so.
The carbon mast will prevent competitors such as the British Olympic team from HAVING to have a "mast program" and spending millions on developing their boat. Rest assured they will find another direction to spend that funding, since they have it.
It won`t make sailing a T more expensive for the weekend warrior - the ally masts will remain class legal for a time at least, and there will still be sailors who are self-funded and sail with the old rig. Those who want to sail a Worlds will spend the money, since it`s a fraction of the real cost of sailing the boat.
What happened to the Tornado by becoming an Olympic class was that the cost of campaigning a boat rose substantially, as happens in all classes. The cost of a Laser has gone up disproportionately with the increase in technology required to build one - they should be the cheapest boat money can buy. It is, after all, only Tupperware with a dacron sheet for a sail on a round tubular alu. mast. You could not design a cheaper boat if you tried, yet they are damn expensive for what you get. This is what Olympic status creates - the perception that the boat is worth more than it is. The sad thing is that the market tends to support this ridiculous notion.

Back to the T - it has long since been a boat that the average cat-sailor can buy & compete with on equal terms to the top sailors. The Tornado Worlds were in South Africa a few years ago, and we have 10 or 12 Marstrom Tornados here, most with the new rig & spinnaker, yet South Africa is no longer listed as one of the Tornado class member countries.
Why ? Because the cost of competing at that level has made it impossible for these sailors to continue without sponsorship, and sailing does not appeal to sponsors in this country since their return on investment is very low with respect to tv coverage etc. It is not worth these sailors effort to even be members of the class anymore.
What this means is that only those with Olympic ideals will continue to campaign the boat, and the boat will no longer be marketed towards, or sailed by, the regular weekend sailor.
The cost saving made at one level of the sport will become a cost increase at the base level, but that won`t concern the class association or the builders - the top level players will buy a new boat every 2 years at least.

If the Olympic selection committee ever choose another cat for the event other than the T, the class will disappear in a vapour trail, with only emty check-books as evidence it ever existed.
Pity, as its a magic machine.

Steve

>>>Carbon fiber is ten times as stiff as aluminum.

This is simply not true !

Check again Bill.

Stiffness to weight may be 10 time more but stiffness in absolute sense is actually comparable.

I think the tornado will keep going for a while longer, and it will be going alittle faster as time goes by.
Mr. Roberts is correct that a smaller/potentially faster mast section could be made in carbon/epoxy. Don't know if they will do that though.
i think it is wrong to say carbon is 10x stiffer than alu. First of all carbonfibers are flexible and come on a roll while alu. comes in a billet. so carbon in it's raw form is actually soft and pliable. Carbon/epoxy masts built with the same shape as alu. bend to the same curve as alu. they can even be built to the same stiffness as alu. the differnce between the 2 is in the reflex characteristics, and the amount of bend. Alu. just keeps bending and it doesn't spring back as brightly as carbon/epoxy.
there are all kinds of ways to use carbon too. There is a kind of nylon resin that is used with it to get rid of the brittle effect. some bike handelbars use it. a bike made of the carbon/epoxy developes hidden cracks if the bike is dropped causing the bike to be essentialy unridable.

What CF Modulus of Elasticity are we talking about from website below, it varies from 200 GPa to 350+ GPa (Alum = 69 GPa)
http://www.geocities.com/CapeCanaveral/1320/


Also perhaps this may help http://www.int505.org/CJ-CarbonSpars505v3.htm

Steve: I agree with you on many points. I dont think the class would vaporize if it lost olympic status tough.
Ref: British Tornado class

Besides, the Tornado has 'always' been an olympic class. That is not new, but the cost of an campaign has rocketed..

What do you think the ITA should do to attract new sailors (while keeping old ones) to the class ? I'm not thinking about olympic campaigns, but regular sailors.

The ITA has to act soon, becouse the olympic charter says that only boats with an widespread use are candidates. Today Germany and UK have quite strong classes, but even the germans had to cancel this years national championship due to lack of interest (20 boats wanted to sail, but the rules demands 25)..

Constructive comments ??

In kiting we used the following numbers for carbon tube. Afterall these tubes are not 100 % fibre but a composite of abou 65-75 % fibre and 35-25 % of low modulus resin. Aluminium can of course be used in a pure form of one single material (alloy additions don't really change this) .

Carbon 80 - 125 GPa
Glass 35 - 48 GPa
Alu (alloys) about 70 GPa (never used twose by the way)


From these numbers the two are quite comparable.

Weight of Carbon = 1470 - 1600 kg per cubic meter
Alu = about 2350 - 2700 kg per cubic meter.


This data came from EXEL a big producer of carbon tubes for kites and buggy kites.

I think that we both may be correct here. You stated the specs of pure fibre and I refered to the spec of a layup with resin. It is possible that over the years they were succesful in replacing resin with fibres making the fibre resin ratio alot higher and creating higher stiffness of the layups. I don't know. It has been several years since I was active in kiting.

Wouter

Hi Rolf,
Sadly, I don`t think the ITA could do anything to grow the weekend sailor base in the class. The boat has been refined and developed into a Formula 1 race car,in order to retain it`s Olympic status. Not too many folks would buy a F1 race car just to go weekend racing at their local track.
Of course I was exaggerating a bit when I said the class would disappear, but the truth is that most top-level T sailors would move onto the next class chosen for Olympics, even if it were the Hobie 16 without spinnaker, as the Olympic medal hopefuls are there for the medal, not the boat. The class would suffer a huge loss at the top-end, and many lower level (mere mortal weekend) sailors would pursue a more affordable class such as F18/Hobie Tiger/ F16/whatever the stronger classes in their own country are.
The Tornado would still exist in wealthy countries, mostly in Europe, but in developing countries other more affordable boats with more local involvement in the manufacturing process will be easier to sell to an already diminishing participant base.

The typical scenario in South Africa : The Dart 18 Worlds in 1999 were in SA, many Hobie 16 sailors bought a Dart just to do the event, so the class grew rapidly, but the hobie class suffered low turnouts for a year up to the Dart Worlds. Then Tornado Worlds came around, so many of the Dart & Hobie sailors swapped allegiance, sold boats & bought Tornados. The Dart class suffered a drop in club turnout from 28 boats to 4 boats at club level at one club alone. In 1999 you couldn`t find a Dart for sale, while in 2000 you couldn`t sell one. Same with Hobies before Tornado Worlds. Now the 10 or 12 Tornado owners would struggle to get the correct value for their boats if they wanted to sell them, because there is no REASON for a demand.
Dart Worlds AND Hobie 16 Worlds are both in SA in 2005, will be an interesting time just after these regattas - I believe there will be a lower South African turnout at both, since sailors will not be jumping classes as much, maybe more stability in the resale value of boats will be a positive outcome. my point is that many Tornado sailors would possibly switch classes if the boat lost Olympic status - not because they have hopes of competing in the Olympics, but because it`s nice to own a boat that has recognition. I think F18 or F18HT will benefit from this if it ever happened, since the boats are easier to transport & cost a lot less to maintain and campaign for a Worlds. At present, how many boats does the Tornado Worlds attract ? 62. Still a fair number by all means, but not when compared to the Dart 18, which attracted a "poor" turnout of 102 boats in 1999, normally over 150 boats up to 300. The cost of sailing a boat is critical - most Dart sailors, even at Worlds level, are just weekend sailors with enough cash for an overseas holiday where they can go sailing for 10 days in a new location. If the ITA could get the average weekend sailors in their class to the Worlds, half the battle would be won. The reason that weekend warriors would feel out of sorts at a Worlds is that the boats have become too expensive to keep up with the top guys. Rig changes, carbon masts, and high-tech manufacturing methods have elevated the cost beyond reach of most.
With Olympic status comes professionalism. Competitors are paid in one form or another to train, compete & sail 8hours a day every day. It`s not sensible to expect a weekend sailor to even attempt to keep up with that. So we find that all Olympic classes lose their weekend sailor base at Worlds & even Nationals level. Once the National level has been eroded to a handful of sailors (Only 20 in Germany, you say?) that are really the guys trying to qualify for their country`s spot at the Olympics, you find that at club level the class suffers, since a Nationals is no fun for a regular sailor when competing with the Olympic hopefuls.
The Finn and Star classes are examples where the Olympics have kept the classes alive longer than they should have survived, they are both fairly antiquated classes in todays terms. The T is far away from that, but has only kept up with the newer designed cats through the rig upgrade (which was forced on them by the Olympic selection committee) and highly expensive manufacturing methods. That, and the fact that the designer got it so right all those years ago.

Sorry for such a long reply, just my thoughts, not necessarily correct, since my opinion can only be based on what I`ve experienced, read or heard throught the grapevine, none of which are reliable sources of information !

Cheers
Steve

Hi Steve, long replys are often _good_ replys.

Some small points along the way. Participation in the T-Worlds are limited based on the respective countries ITA members. All nations are allowed one team, but countries with many ITA members are allowed additional slots (up to 4 i think). So there would probably be more than 62 teams at the worlds if it was open for all.

In Germany they alternate the nationals between the coast and the inland (lakes). 2003 saw some 32 boats participating with lots of older sailors, some quite young and mostly weekend warriors. There was three or four olympic teams present then.. I dont know what caused the low numer of teams this year, perhaps the prospect of little wind?

Would it be insulting to say that you basically think that the T is kept artifically alive by the olympics?

Professionalism are making some disturbances in our sport, as you say. And we regular guys are of course not competitive with the pros'. But doesn't your 10-12 Marstrøms (and I bet there are other T-designs in SA +neighbouring countries as well) go out racing and have a good time? If they dont, why? Lack of initative, acceptable goals or general apathy?

In 2003 the swedish championship was cancelled due to lack of interest. Then some T sailors started to sail together in Stockholm. This year 7 T's came to the SM, and the class Assoc. had its first meeting in 6-7 years. Now they are working to have 4 official regattas next year and to get more boats to attend.


The start price in the T is not that bad, considering that it has a crew of two to share the cost. But of course changes like the carbon mast hurts a bit. The other olympic classes like the Laser should be hurt by professionalism just as much, but at least here in Norway both the Laser and Europe thrives.. (even tough we have professional teams in both classes)

I would like to hear other peoples toughts about the lack of T interrest and what could be done.

PS: Steve, I guess you know that the Hobie 16 are still trying to become the olympic multihull

I`ll try to keep this one shorter .
Ok, entry to Worlds limited - I never knew that.

"Would it be insulting to say that you basically think that the T is kept artifically alive by the olympics?"
No, quite the opposite - I think (my opinion only) that Olympic status can do more to harm a healthy class than help it grow. Basically the class grows at the highest level at the expense of membership at the base. When a setback at the highest level occurs (such as being replaced as the Olympic boat), is there still enough of a membership at the weekend level for the class to survive? Has the Soling survived after being dropped from The Olympics ? I don`t know, but would guess against that probability.
What I`m saying is it`s kind of like a vicious circle - The boat gets selected for the Olympics, then in order to remain the Olympic boat they have to keep changing to suit the IOC selection requirements. So they do this for 20 years, only to find they have out-priced themselves in the base market, ie us, the weekend sailors. NOW they HAVE TO REMAIN the Olympic boat to keep their popularity.
The T is a great boat, but for a lot less money you can now buy quite a few very nice boats, F18/F18HT etc.
Would the T remain as popular without being the Olympic boat ? I can`t answer that, but I have my own ideas.
Would it have grown to what it is now without Olympic status ? Of course that is impossible to answer. It would probably be less high-tech,less expensive, and have more builders involved, as the only reason it has funneled down to one major builder is that everyone MUST HAVE the boat that won last year`s Worlds. The original olympic classes could be home-built and was in fact a criteria for the selection, this is long gone.

"Professionalism are making some disturbances in our sport, as you say. And we regular guys are of course not competitive with the pros'. But doesn't your 10-12 Marstrøms (and I bet there are other T-designs in SA +neighbouring countries as well) go out racing and have a good time? If they dont, why? Lack of initative, acceptable goals or general apathy?"
Unfortunately they don`t race often, for all of the reasons you list. It`s a lot of work to travel to an event, set up the boat, and take time off work, pay accommodation etc, for a Nationals where maybe 6-8 boats will attend, if we had 30 boats and 20 of those attended it would be more worthwhile. Our situation is so different - take the price of any boat and multiply it by 8,5 - that`s realistically what a boat costs us. If you earn R10 000 and a new Tornado costs R 300 000, that is the comparison. 30 times our income. So there won`t be too many more imported T`s here. Our Marstroms are over 10 years old, so not worth spending all the money to attend a Worlds where the newer boats have the advantage. So that goal is out of most people`s reach.

Of course here a Laser and Hobie 16 costs around R65 000, while a brand new entry level car costs R80 000, while there can be no comparison in the effort & technology required to build each. So that has killed sailing here to a large extent. We have a few 49er`s, 10 or so 29er`s, not enough boats in each fleet to build on. We must produce locally to keep sailing reasonably affordable, which is what is happening.

By the way, I can buy a complete Mosquito, (16ft "miniature Tornado" ) for R50 000, or 6275 Euro, probably the same price as the new carbon T mast ! It has carbon reinforced epoxy-foam sandwich hulls, carbon boards & blades, full mylar sails, spinnaker, and weighs about 100kg.

I think the problem with our sport is that it is way too fragmented, there are more boats than sailors, and still more boats being designed every day. When a new class is introduced, it will grow at the expense of an older class, I suppose that is evolution, but not growth.

Cheers
Steve

There is no doubt in my mind that this is the case here in Southern California. All the T sailors here survive on used sails sold by campaigners. It's a very affordable class if you are willing to buy used equipment. None of us would buy a new boat.

However, the last 2 times we've managed to get 2 T skippers together, we could see a fleet of Tigers and Inter/Nacra-20's (carbon mast, BTW) racing in the distance.

The carbon mast is not the reason the T fleets will not be growing, since the Inter-20 has a carbon mast and is a very popular racing boat around here and is selling well. IMHO, the things that make the Tornado a hard sell are the wide beam (making trailering difficult), the cost (double that of a Tiger), and the reputation for being unrightable (although I've seen Gary Friesen right my Tornado *solo* with a righting pole), the fragile gaskets that keep them off the beach, and the wide tacking angle because of the centerboards and wide beam and sloop rig (which make tacking up narrow channels a bit tedious).

I'd not recommend a used Tornado for a novice, though I would recommend a used F-18 Tiger, although I would advise them to leave the bowsprit at home for the first year at least.



I don't see how Olympic status would hurt the F-18 class, or the Hobie-16 if it were adopted. The Tornado's problems have nothing to do with that.



Here in the US, it's a cultural problem: Americans want to be entertained in their time off more than ever, and are sailing less. Attendence at all regattas (not just Tornado regattas) is down. The Tornado, being the most exclusive class is hit first, but volume is so low the venerable Hobie 18 stopped production and even at Hobie regattas some classes can't get enough boats for a start.

We would love to get enough (4) boats together to get a start at a local "Olympic Classes" regatta, but we haven't been able to get that many boats together yet, and if we do, we know the finish order is likely to be 1994 Marstrom, 1980's sailcraft, 1980's sailcraft, 1971 Panthercraft (with a possible hand-made wooden boat thrown in there), since those are the boats in the region.



I have never, ever, ever heard of anyone sharing the purchase price of a boat with their crew (unless they are married). The Price:Performance ratio is definitely important, and you can get almost as much performance for much less money from other boats.



IMHO it helps the Tornado. Anyone fanatical enough to buy a Tornado for performance wants all they can get. Anyone campaigning will get a competitive mast at a fixed price and the mast properties will better match their sails. Old boats are not competitive, with or without the new mast.

The price problem comes from the fact that the competitive boats are built using expensive materials, techniques, and tooling that only a single vendor has invested in (and considering the volume, who else would try?), and noone is building noncompetitive boats because there is no market for them.

One of the problems with a boat becoming an Olympic class is that the price usually goes up, making the boat less affordable at the lower levels of racing. I have always heard that one of the reasons the price goes up is because the boat becomes more expensive to build -- the manufacturers have to have much tighter quality control and much smaller tolerances for all aspects of the boat.

Personally I think it's great to hear that the T went with a carbon mast. I think they will develop the carbon mast and really perfect it. This technology will bubble down to the other classes and we will get the advantage of having a cheaper, better, carbon stick than we could otherwise. The T class needs to stay leading edge to keep worldwide interest.

Mike Hill
Tiger #1520

Hi Gang,
It sounds like the Tornado class wants a carbon mast no matter what. The headline has now changed to a safety point. "Any reason to support the position in favor of the carbon mast is welcome".
A shroud extension system would make the Tornado one person rightable and the parts cost about $100.
A new aluminum mast extrusion die paid for by the manufacturer would solve the mast extrusion inconsistency problem. If there is a problem with variations in the mast taper, this can be solved with laser cutting and robotic welding. This is twenty year old manufacturing technology. I see none of these solutions being suggested. The Tornado class wants a carbon mast no matter what and that is all there is to that.
The Finn class decided to go with a carbon mast a few years ago and now their mast situation is a mess; no satisfactory solution. The masts still break like match sticks.
Learn from experience:
The sailboard industry tried carbom masts about 25 years ago. The first ones were very stiff; too stiff to work at all. The parts were built with fiberglass tooling. The next step was to go down in mall thickness. This was tried; these spars would bend and they proved to be very fragile. Many of the thin wall spars broke while the sail outhaul was being tightened. The rest of them broke while sailing. Carbon sailboard spars got a bad name and the enthusiasm for the carbon sailboard spar fell off for a few years. Then finally along came a carbon spar that was about 75% of the diamenter of the glass spar with a thicker wall than the old carbon spars and the new one was bendy and lightweight and tough. Hot Dog, somebody finally found the answer! They had adjusted the mast diameter and wall thickness in coordination with the modulus of elasticity of carbon and came up with a part that bent much like the glass spar and was much lighter in weight and tough.
If the Tornado class is going to have a satisfactory carbon spar that bends much like the present aluminum mast, the engineers/designers are going to have to have a clean sheet of paper to work with. No rules like "it has to be the same outside shape as the present aluminum mast". A rule like this is guaranteed disaster. There is too much difference in physical properties between carbon and aluminum to impose this limit on the carbon mast.
Bill

Now that I agree with. To stay with the same extrusion parameters but go to carbon doesn't offer much.

We'd also need a captive ball mast step, no? With shroud extenders, I've never understood how you get up to the high side to pull the pin when it's ~10 feet off the water. Please explain...

Bill,
let it go. you don't even sail a tornado. Carbon is a great material and many sailboat masts are built with it. Granted they are still learning the best way to go about it,and it is more costly, but it is the future.

On your sailboard example you mixed the apples and oranges. Carbon didn't replace glass masts for racing. Racing masts were alu. and during the first couple years of carbon masts some racers still used alu. as the first carbon masts were too stiff. the glass masts are used in the waves. they still are mostly glass. Windsurf masts are labled by their pecentage of carbon and by a system for gauging the flex characteristics. Some of the masts are skinny and some are the same as they ever were. The racing masts have more carbon and thinner walls.

For most things on a cat-lighter is better

Hey Mike,
No problem, you just have to be ten feet tall!
Well, not really. You climb up on the mast at the base and stand there and reach up and aft to the shroud lever and open the lever and pull the extension pin. Then climb back down to the lower hull and pull on the righting line and up the boat comes.
As to the captive mast step housing and ball: Get those parts from Aquarius Sails and adapt them to your present system.... OR ,,, Before you extend the upper shroud, tie a short piece of line tightly connecting an eye strap located at or near the bottom of the mast to the main beam. It is just a short piece of line going through the eye strap and around and under the main beam. Pull it tight and tie a square knot. This loop will keep a non-captive mast step connected. Then extend the shroud and right the boat. No problem. I have helped several sailors rig other brands of boats this way. Some boat owners have even installed a cleat on the bottom of the main beam to eliminate the need for the square knot.
Opening the leeward shroud lever is a "go fast" in light air downwind in that it allows much more mast rotation. It takes the tension out of the leeward shroud and then the mast can push it out of the way and rotate much more.
Good Sailing,
Bill

That is no reason to not voice an opinion, especially when this thread has changed into a discussion about the decline and politics in the T-class (and general sailing).

I have sailed Tornados for just four years now, but we have never had any problems righting it with an ordinary righting line thrown over the hull. Not even when sailing with a crew weight of 150 Kg. I have even seen a 160kgs team right a pitchpoled T (before it went turtle).

Besides, as Roland Gaebler said "we are not sailing these boats to be safe"

I've seen my Tornado with aluminum mast righted single-handed with a 6' righting pole. (Pictures at http://photos.groups.yahoo.com/group/TornadoCat/lst under "SoloRight".)

need a login to access that.....

I think we can trust Marstom to come with a good top quality mast with longlivitey.

Wouter

It seems apparent that Bill isn't in favour of most anything that he hasn't "incorporated" whithin his boats, but that doesn't mean that other innovations are not good.
Carbon is the way that ALL boats are going, LIKE IT OR NOT. It is similar to the transision from marine ply as the favoured building material for most if not all the high performance sailing craft of that time, to fibre reinforced plastic (polyester and E glass). There were all sorts of "wild" reasons given that fibreglass would NEVER replace ply. To heavy, to slow, to expensive, and UNSAFE, were just a few emotional "reasons" that were given at the time, (sound a little familiar?). Well, we are at just such a watershed in the development of "the next generation" of building materials right here right now, and nothing is surer than over the next few years "if it aint carbon/kevlar, then it aint there"
There is a load of conjecture and, I may say "Rubbish" being bandied about the diameter, the comparison to aluminium, the comparisons to "wind surfers" wall thickness etc, for the Tornado carbon mast. You only have to look to a class that is more appropriate that successfully converted to carbon masts years ago without "reducing" diameters etc, and is growing (as a class) more now than at any time in their history. The A class is the example that Tornado's should be looking to for validation of their decision to move forward into carbon masts.

Probably flogging a dead horse here, but..

Mitch Boot and Darren Bundock has made some statements regardring the last ballot..

Ref: The German T Assoc (in english)

Rolf,

Can you post a copy of these comments here (and/or on the TornadoCat forum on Yahoo)? The link you provided is all in German and it's not obvious (to me at least) where to go to get to the comments.

Mike.

Sorry about that Mike!

In the meantime, the posts has 'disappeared' from the german forum (as controversial posts has a tendency to do there from time to time). Both posts was forwarded from them, and written in english. The next time I will post them here instead..

The basis was that both Mitch Booth and Darren Bundock supported the ballot to further the 'one-design' element in the Tornado class. Mitch eleborated, as mentioned here, that the boat/equipment was just 1/3 of the cost of a campaign. The rest went into travelling, hotels and coaching..

Here is the post in question

Tornado New Rules von Mitch Booth

Autor: Flippo
Datum: 09.09.04 12:43

Dear Tornado Sailors,

Finally, after 5 months of full on sailing I now have a chance to comment on the ballot and its impact.

The pre-text to the ballot form and so called intention of what the ballot was trying to achieve is far from what the class started as many years ago.


The class has always allowed and still does permit owner builders to build 1 boat a year for their own use. Many sailors from all levels have exercised this right to make part or full boats. We have made over the years hulls, rudders, centerboards, sails, booms and even masts.

I am a strong supporter of the one design concept however, there is a big difference between "one design "and "one manufacturer". This whole idea that no sailor should be able to use something that is not commercially available to other sailors is totally against the spirit of the class rules. We have strict tolerances, materials and rules to abide by and we can make them even tighter if we want.

The point I am trying to make is if the class wants to go towards the commercially available and same equipment for all sailors then we have to scrap the owner builder rule and change the class to a "manufacturer supplied only" rule just like Hobie or Nacra. Personally I think this would damage the future of the class and it would lose its edge as the leading beach cat.

There are two major flaws I find in the ballot.

Firstly, under the current rules 3, d, an amateur builder is allowed to build a boat a year for his own use. This of course includes a mast if he wishes.

Secondly, the rule 17b, 1 and 2 talks about "Schedule A- approved sailcloth" However there is no wording as to the criteria , method or persons to create this list. We have earlier this year gone through a rule interpretation on spinnaker cloth and it was clear from ISAF that no matter how much supporting correspondence as to the intention they would ONLY rely on the wording of the rule. I believe the new rule is not enforceable in its current form.



Good Sailing,

Mitch Booth



Auf diesen Beitrag antworten









Re: Tornado New Rules von Bundy

Autor: Flippo
Datum: 09.09.04 12:45

I agree that the class should remain one design and not one manufacture to encourage a little bit of development. However, the class must put in place some steps to prevent the class becoming elitist.

The circumstances have changed over the years since the class started many years ago, now many teams are professional sailors, some MNA's are pouring in exorbitant amounts of money and the amount of sponsorship money in the class has risen substancially. Something needs to be done to level the playing field to low budget teams.

I believe the class has taken some positive steps in this direction.

I don’t see it damaging as at this stage the carbon mast is the only part to be strict one design and one manufacture. If it passes the ballot with a greater than 2/3 majority then it is what the class is wanting.

You are correct that a amateur builder can still build one mast a year for his own use. Only 1 not a practice one and then a real one. I believe it must also come out of an ISAF certified mould as well.

I am unclear on the wording of the new 17b, as I do not have it here with me. But for sure it needs to have clear guidelines for selection of material to get approval to be listed on "schedule A".

I have confidence that the ISAF will approve something that is fair and binding.

Regards
Bundy

I don't interpret those posts as very supportive of the carbon mast - both of them point out conflicts in the new rule and Booth points out how this rule seems to contradict the nature of the class.

Jake: I'm reading their statements as supportive of the carbon mast, but they are obviously concerned about the direction of the T-class.
I might be totally wrong of course, but as english is not my native language, I have an excuse ready

Good thing that Steve had the postings at hand tough!

My interpretation is that while they didn't exactly come out and say "We don't like it", Booth is illuding that the class seems to be migrating to a single manufacturer one-design (like I've been saying) and getting away from the multi-manufacturer one-design that the Tornado class has always been. He feels that this is bad for the class. Having only one supplier of the carbon masts is clearly a move toward a single manufacturer one-design.

Bundy, on the other hand, seems slightly less opposed to the decision and while he agrees with Booth's multi manufacturer one-design ideas, he doesn't think the carbon fiber mast decision will be damaging to the class. Actually, neither seem to be against the carbon fiber mast but rather the idea that they are legally only available from Marstrom.

Well, this restriction is supposed to be for 2 years only...then other manufacturers are permitted, assuming they can get certified and pay a royalty to Marstrom. I guess it will come down to...can anyone else build a better/cheaper mast than Marstrom and make enough profit to commit to it.

And after the royalty too. Does anyone believe that there can ever be a second manufacturer in this scenario? I don't.

This is interesting to me because we just had a similar discussion this weekend regarding F18 and one design. A minority of our area F18 sailors (actually just one of them) is concerned that departing from Hobie Tiger class rules and opening up to F18 (since the recent insurgence of the Nacra F18 in the area) would be detrimental due to the arms race. The majority concensus was that it would be healthy to start considering ourselves full on F18 and forget about one manufacturer one design. I think the argument is Moo since evidence suggests outside manufacturer sails are actually cheaper than Hobie or Nacra.

(By the way, the point is "Moo" because who would listen to a cow's opinion? )

Well Jake on the "UDDER HAND"????