Sail Shape Indicator Stripes.

ROY SCOTT · Post by **ROY SCOTT** » 23 Nov 2003, 19:39

The IOM Class Rules regarding sail shape indicator stripes address only three issues, the width, the number allowed on each sail and the method of application, (G4 and G3). The positioning is not addressed so one goes to the RRS.and cascading from appendix G, through appendix E, to ISAF â€“ RADIO SAILING DIVISION â€œIdentification on Sailsâ€

VCinfocomms · Post by **VCinfocomms** » 25 Nov 2003, 13:01

[quote="ROY SCOTT"]Are indicator stripes to be considered â€œother identificationâ€

ROY SCOTT · Post by **ROY SCOTT** » 01 Dec 2003, 20:35

Hi Lester,
Thanks for your input.
The Class Rules are specific in terms of number and thickness of Sail Shape Indicator Stripes. This being so, I have to believe the limitation is in the interests of keeping the sails tidy and the numbers/other identification clearly seen. If your thoughts regarding "decoration" are carried to ultimate then legibility could arguably be compromised.
In that there is no mention within the Class Rules of decoration on sails or how it might be applied then, by definition of rules interpretation, it is not allowed.

Does this open up the question of spacing again???

Post by **Chairman** » 05 Dec 2003, 10:48

ROY SCOTT wrote:The Class Rules are specific in terms of number and thickness of Sail Shape Indicator Stripes. This being so, I have to believe the limitation is in the interests of keeping the sails tidy and the numbers/other identification clearly seen.

Hi Roy

I'm not an "official" expert on the class rules, but my understanding is that the limitations on draft stripes are to prevent such stripes being made of material which could give stiffening to the sail. I do not believe that legibility was uppermost in the minds of the rule makers at the time.

In that there is no mention within the Class Rules of decoration on sails or how it might be applied then, by definition of rules interpretation, it is not allowed.

The class rules permit "advertising", and this is why I thought that "decoration" might come under this heading. But there does remain the issue of legibility, as you say, and perhaps it would be useful to amplify the App.G prescription to say that legibility shall be at least as good as an "undecorated" sail, that is, a sail free of all advertising.

ROY SCOTT · Post by **ROY SCOTT** » 05 Dec 2003, 18:28

Hi Lester,

Your rational is logical and evidently since boats have sailed at open meetings with proximity of the stripe nearer to numbers than the 60 mm (ISAF â€“ RADIO SAILING DIVISION â€œIdentification on Sailsâ€

RoyL · Post by **RoyL** » 17 Dec 2003, 00:34

Since the current rules are very explicit about the number and size of draft stripes I would think that anything that doesn't conform (like a fourth stripe on the main) has to be prohibited. Fact is extra or larger draft stripes make it easier to read your sails--to me a clear performance advantage. (I have even seen sails out there where a whole panel has been colored in.)

As to the issue of numbers, I and others have noticed that certain colors can be very hard to read on some sail materials particularly with the sun shining through. If the goal of the number rule is identification and legibility, some standard for "darkness" or "contrast" is possibly necessary.

Steve Landeau · Post by **Steve Landeau** » 17 Dec 2003, 17:23

Agreed, Roy. Lester and I talked breifly about this at Fleetwood, and if I remember correclty, we were leaning toward "Black numbers on a White background", regardless of sail color. I agree completely that something should be done about this situation. Clear sails, and colored numbers are sometimes very hard to identify, and I've seen protests dismissed due to improper hails.

Chris · Post by **Chris** » 22 Dec 2003, 21:13

Here's a spanner in the works - can not the person use different coloured sail clothy between panels. i.e top panel white, second dark blue, 3rd white, bottom dark blue as long as the material complies with G.3.1 (a) (1)

On top of this the 3 sail stripes can also be used.

Post by **Chairman** » 23 Dec 2003, 12:31

Chris wrote:Here's a spanner in the works - can not the person use different coloured sail cloth between panels. i.e top panel white, second dark blue, 3rd white, bottom dark blue as long as the material complies with G.3.1 (a) (1)

Chris, it is G.3.1(a)(2) that would worry me.

IOM Class Rules 2003 wrote:G.3.1 (a) (1) The construction shall be: soft sail, single ply sail. (2) The body of the sail shall consist of the same ply throughout and of not more than four parts joined by seams.

I'm not sure (unofficially, of course!) that a "white panel" and a "blue panel" are of the same ply.

Rob Davis · Post by **Rob Davis** » 23 Dec 2003, 13:55

Chairman wrote: Chris, it is G.3.1(a)(2) that would worry me.

IOM Class Rules 2003 wrote:G.3.1 (a) (1) The construction shall be: soft sail, single ply sail. (2) The body of the sail shall consist of the same ply throughout and of not more than four parts joined by seams.
I'm not sure (unofficially, of course!) that a "white panel" and a "blue panel" are of the same ply.

The rule is not quite specific enough to me to be sure that same ply means nothing other than type of material is to be the same. I read it to not address the color or opacity of the material. Possibly a member of our Technical team could weigh in.

Steve Landeau · Post by **Steve Landeau** » 23 Dec 2003, 16:56

I would expect that if it were the same style of material, it should be allowed. Use clear compared to white drafting mylar; 1.4 mil thickness is the same ply regardless of whether or not you can see through it. One has a light film sprayed on it so you can't see through it, the other does not. That's not part of the "ply".

Post by **Chairman** » 23 Dec 2003, 19:50

Well, here is the ERS definition.

Equipment Rules of Sailing wrote:G.1.3 Ply: A sheet of sail material.

Then, if we put this into the class rule, we get:

IOM CR wrote:G.3.1 (a) (2) The body of the sail shall consist of the same {sheet of sail material} throughout

Does this mean that a sheet of blue material is different from a sheet of white material, other things being equal? I read the word "same", and it is this that makes me think that maybe the rules do count blue material as different from white material even if both are, say, 35 micron mylar drawing film...

Steve Landeau · Post by **Steve Landeau** » 23 Dec 2003, 20:11

It is essential that when reading the IOM rules, a certain level of common sense is expected. This rule (G.3.1(b)) CLEARLY means that you may not use different thicknesses (or weights) at different parts of the sail. If one were to take it as far as which color the 35 micron material is, one wouild also expect to make sure it came from the same manufacturing batch. Now how would you prove that? Before we go this deep into what "ply" really means, maybe we should go back to the color question and ask ourselves "does color really change performance, and is it really necessary to make a rule that clearly allows you to glue one color to another?". A perfect example of this is spinnaker material. Many one design classes restrict the weight of material, however you can make a pattern using different colors. So long as the WEIGHT does not change, you are still using the same PLY of material.

ROY SCOTT · Post by **ROY SCOTT** » 23 Dec 2003, 20:18

To argue that the rule G 3.1. (a) (1) (single ply) and (2) (same ply)is breached when using different coloured panels of otherwise same material/ply seems to be moving towards finely shaving definitions for the sake of argument to no real value. I would be more concerned with the interpretation of same ply when applied to the primary and secondary reinforcement where just about every sail seen has woven Dacron (or similar) for this on Polyester film panel sails. How do we argue that woven Dacron (of various colours!) is the same ply as Polyester film when we then argue that different colours on the same material/ply Polyester film in the sail panels is not?

Steve Landeau · Post by **Steve Landeau** » 23 Dec 2003, 20:20

ROY SCOTT wrote:
The Class Rules are specific in terms of number and thickness of Sail Shape Indicator Stripes. This being so, I have to believe the limitation is in the interests of keeping the sails tidy and the numbers/other identification clearly seen.

I was under the impression that the indicator stripe rule was created to prevent the use of "disguised" full battens. Using a thick tape substance as striping material could easily be a functional batten.

Rick Martin · Post by **Rick Martin** » 23 Dec 2003, 20:29

Steve Landeau wrote:I would expect that if it were the same style of material, it should be allowed. Use clear compared to white drafting mylar; 1.4 mil thickness is the same ply regardless of whether or not you can see through it. One has a light film sprayed on it so you can't see through it, the other does not. That's not part of the "ply".

As an owner I completely agree with Steve here, however, as a member of the Technical Subcommittee (which I happen to be) I would have to say (unofficially) this would benefit from official interpretation because it could always be argued that colored and non-colored panels/plys are not "the same" they are different.......i.e. different colors. A good question for the class is would we want to permit multi-colored sails and accept the appearance consequences? Personally I like the rugged look and personality of the IOM as it is and would not go for changing that image through multi-colored sails.
Respectfully,

RoyL · Post by **RoyL** » 23 Dec 2003, 23:19

I think things wandered a bit here. I would assume that we all agree that if someone took a white or clear sail and colored an enitre panel (say with a marker or paint) that it would violate the draft stripe rules?

Post by **Chairman** » 24 Dec 2003, 00:42

ROY SCOTT wrote:I would be more concerned with the interpretation of same ply when applied to the primary and secondary reinforcement where just about every sail seen has woven Dacron (or similar) for this on Polyester film panel sails

Hi Roy

There is no requirement for primary or secondary reinforcement to be "of same ply". According to the class rules, this requirement is only for "the body of the sail".

Post by **Chairman** » 24 Dec 2003, 01:06

Steve Landeau wrote:If one were to take it as far as which color the 35 micron material is, one would also expect to make sure it came from the same manufacturing batch

Hi Steve

It gets worse

"G.3.1 (a) (2) The body of the sail shall consist of the same {sheet of sail material} throughout". Does this mean it must come, not only from the same batch, but off the same roll? Or, much worse, that it must be a contiguous length of material which happens to have been cut into separate panels? I sure as heck hope not.

There are other possible differences between sail materials for radio sailing. You mention clear and white mylar as an example, where the white is clear with a fine layer of paint. Is white "the same" as clear (assuming that both are mylar, both of the same weight)? Hmmm... I was wondering about clear and frosted mylar as an even worse case, where frosted is clear with fine acid etching. Is frosted the same as clear? Even better, is it the same as white? Don't know.

(Who would have thought that the question of what the rule means when it says that "X must be the same as Y" could be so, ah, interesting? Sounds like Rick is right, an interpretation might be useful.)

Post by **Chairman** » 24 Dec 2003, 01:33

Steve Landeau wrote:maybe we should ... ask ourselves "does color really change performance["]

This is a particularly important question, of the sort that regularly pops up in discussion of the IOM class rules. That is, does some feature X of the boat affect performance? In this case, and many others like it, I'm pretty sure that it doesn't. The IOMICA Technical Sub-Committee is working on a "Policy and Intent" document for the IOM, but my (unoffical!) expectation is that it will say that "performance" is not the issue in the IOM.

http://www.iomclass.org/Information/General/IOM%20Current%20policy.htm wrote:The tight class rules [are] designed to produce uniformity in the yachts and equipment

That is, the key issue for the IOM class rules is to create a "sailing game" of a certain kind, different from the "sailing game" offered by other classes. Like other closed classes, the intent of the rules is to limit (if not eliminate) variation, flexibility, and/or differences in certain areas for the sake of the "sailing game" it wishes to provide, without reference to whether the limitations it specifies are performance-related.

Finally, there is the point that whether something has an effect on performance or not is not an issue when determining whether something is legal or not. The issue is, does it comply with the class rules?

Post by **Chairman** » 24 Dec 2003, 01:51

Steve Landeau wrote:Now how would you prove that?

This is another deep question for any set of class rules! Should class rules only ever specify things which can be proven? Or should they specify whatever they like in the interests of trying to set up a certain desirable "sailing game", and leave it up to the rule-exploiter to take a risk if they have a mind to do so?

A current example in the rules is the alloy designation of a spar. If I buy a length of aluminium tube from my local DIY shop, how can I prove that it is 6061 grade? And how can any Official Measurer prove that it isn't? (Yes, alright, a very expensive and fancy piece of laboratory equipment can do the job, but do you know of anyone who has access to such equipment, never mind actually owning it?) To all practical purposes, it cannot be proved if my mast is 6061 aluminium. Yet, does that matter?

And then, what are the consequences if the rule simply says, for example, that a spar shall be primarily aluminium (because no one can prove a specific alloy designation)? Would this not open the door to some pretty fancy spars (read expensive!) and so defeat one of the primary purposes of the IOM in the first place (an inexpensive International class)?

ralph kelley · Post by **ralph kelley** » 24 Dec 2003, 17:09

Lester:

Reference your comment on alloys for masts.

As you may remember a couple years ago, I was strongly in favor of eliminating the alloy specifications for both the masts and booms during the time that the current 2002 IOM Rules were being drafted. I was unable to sway the Rule developers toward my position and we currently have the situation you described -- normally unverifiable components in our craft.

My mast supplier advises me that he could, on demand, produce procurement records to verify material alloy, but I suspect that he is in the minority of spar suppliers. Given this documentation, I would have to maintain records to prove that this documentation was applicable to the mast(s) used in any one particular rig. This is the kind of thing required for us to truly meet the class Rules. This is obviously impractical for what we have to remember is a hobby.

I doubt that he could provide documentation that there has been enough destructive or non-destructive testing of the tubing lot to prove the wall thickness variations are within class limits (0.1 mm)

Likewise I could probably go to Easton and get some documentation as to the alloys used in the arrow shafts I use for booms, but I have not done so, and it would be a real hassle for every IOM owner who uses arrow shafts to do the same. And Mr. Bantock would have to provide documentation on each and every one of his extruded booms as to material alloy and wall thinkness control for his very popular booms. I think this is also impractical.

Lastly, for spar materials. the rule developers went to great pains to specify alloys of aluminum but simply state that any wood is OK. Now the Modulus of Elasticity (the key material property that impacts the degree of deflection under load) is essentially the same for all aluminum alloys. Put differently, just about any tube of the same shape would bend the same amount, regardless of the alloy selection. So specifying the alloy content has to have been based on something other than spar bending considerations. If the specified alloys was based on commercial availability of tubing in the sizes we want, then the alloys need not be specified -- we simply use what is available.

So as I indicated in another posting, we need the Rules to be worded so that inspection and verification are considered, and at the same time, don't go overboard with over specification.

Something for us to address when in the coming years.

Ralph Kelley

Steve Landeau · Post by **Steve Landeau** » 24 Dec 2003, 18:14

Quote: "The IOMICA Technical Sub-Committee is working on a "Policy and Intent" document for the IOM"

This will be a very nice addition. I understand that some rules are written for performance reasons, some for cost control, and I'm sure there are a few other reasons as well. It will be nice to know the intent of certain rules that sometimes don't make sense. Having the intent documented will certainly help.

Steve Landeau · Post by **Steve Landeau** » 24 Dec 2003, 18:38

Quote: "And then, what are the consequences if the rule simply says, for example, that a spar shall be primarily aluminium (because no one can prove a specific alloy designation)? Would this not open the door to some pretty fancy spars (read expensive!) and so defeat one of the primary purposes of the IOM in the first place (an inexpensive International class)?"

Well, the class has long passed it's intent of an inexpensive boat. Most hulls in production are about an average of $800 US, and then you'll need to add rigs and electronics. I still think it's a great bargain for the versatility the boat offers, as they'll sail in just about any weather conditions you are willing to stand out in. Martin Roberts has proven you don't need all the exotic, custom rig components offered by some suppliers to make a boat go fast, and anyone coming into the class will certainly look at who is doing what with what. So, is it possible to build a winning IOM inexpensively? Of course. But, to say that the rules have kept it cost efficient as a class in general (as it was intended) would be stretching the truth a bit.
As for the rules that cannot be proven, you must remember that this is racing. And if you are racing, someone is always looking at the rule to find a way to bend it to their advantage. If a rule can be bent to give an advantage, it should be watched closely. Some of our rules are completly meaningless, AND cannot be proven. I'll take one current interpretation for example; use of fillers in gelcoat. Current interpretation says it is not allowed. However, gelcoat is nothing more than pigmented polyester with added filler to increase viscosity. We can't add fillers to it by rule. Now I ask this (and not directly to you, Lester), what does this rule control? Why should it be illegal to thicken some gelcoat, and if one did, what would one have to gain that would validate a rule against it?
In closing for this topic (for me), I'll say that in general, the rule of the IOM is what makes it such a great boat, but I'd say about 10% of it is just plain stupid and has no real value. It is this 10% that makes it so controversial. Will it end, probably not. We'll just live with the occasional paperwork headache, bitch about it online for a while, then go sailing on the weekend and hope to forget about it.
Everyone have a great holiday, and try to get some sailing in over the long weekend.

Post by **Chairman** » 03 Feb 2004, 19:26

Chairman wrote:It gets worse "G.3.1 (a) (2) The body of the sail shall consist of the same {sheet of sail material} throughout". Does this mean it must come, not only from the same batch, but off the same roll? Or, much worse, that it must be a contiguous length of material which happens to have been cut into separate panels?

Stumbled across an official ISAF interpretation in the Yngling class that has a certain relevance.

http://www.sailing.org/makingwaves/2004/182_020204.asp wrote:Yngling - In accordance with ISAF Regulation 26.11.1 a Class Rule interpretation to the International Yngling Class Rules is confirmed and will be effective 30 January 2004.

Class Rule G.2.2 â€“ Mainsail construction
G.2.2(a) The construction shall be: soft sail, single-ply sail.
G.2.2(b) Except within 250mm of the foot, the body of the sail shall consist of the same woven ply throughout. The ply fibres shall be of polyester.

Question submitted by US Sailing
â€œWeâ€™d like to know the interpretation of the class rule and if it allows two different finishes of the same exact weave and weight of cloth in one sail. Specifically would it be legal to use 4.46PK (hard finish) on the bottom/top and 4.46pp (soft finish) in the middle?â€

Steve Landeau · Post by **Steve Landeau** » 04 Feb 2004, 02:44

Well done, Lester.

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