IOMICA Forum

Alright, everyone this is your chance to be heard. The next IOMICA AGM is coming in June. Things seem to be running pretty smoothly in the class at present. However, to the extent you believe there are changes that need to be made in the class rules, this is your opportunity to put them up for discussion and convince one or more NCA's to put your proposal on the ballot. To the extent you think there is an emergency that can't wait for a vote, you can also put your thoughts out here and the IOMICA Exec and VC Technical will all be listening. I've already raised a few topics below on this forum. Now its your turn.

There is an issue which remains outstanding in the IOMICA Technical Sub-Committee, I believe, since circa 2004. It is a problem with battens, mainsail battens in particular, where a piece of reinforcement is wrapped around the batten at the leech to hold it firmly in place.

At the simplest level, this wrap projects beyond the leech (by a small amount!), and hence is aft of the straight line between the batten points, contrary to class rule G.3.1(a)(5). (Worms crawl out, though, if you feel that the problem is solved by simply having the reinforcement not wrap but just sit on one side of the sail. Is this reinforcement permitted by G.3.3? Is it a batten pocket?)

Depending upon how you count it, I would guess that 50% - 80% of all IOM mainsails are technically out of class because of this. I don't know of any measurer or event inspector who has picked up on it, but who knows what some hyper-enthusiastic Eagle Scout might think, not to mention the possibility of successfully protesting almost the entire fleet at a major regatta...

The issue of batten pockets is interesting. On full size sails pockets are used so that the tension on the batten can be adjusted. The idea (and the inference of the word pocket) is that the batten is removeable, can be changed for a stiffer one or the tension adjusted. On full size sails the pocket and its tensioning/retaining device can stick out behind the leech. Its for this reason the size of pockets is limited so that no significant sail area can be gained.

Looking at the IOM it is the leech (of the sail) that shall not extend aft of straight lines between ............ A batten pocket is not the leech of the sail so presumably can extend beyond but by how far?

Also you don't have to have batten pockets (see G.2.4.) and a holding patch at the inner end could be a "batten pocket patch" ERS G.6.4 and a "flutter patch" which under G3.3 at 50mm could cover the end of the seam and by coincidence hold the outer end of the batten. So what is a batten pocket and who needs one? Under G.3.1(a)(4) it would be possible to have 3 batten pockets holding one batten!

With reference to my earlier thread about sail diagram the batten issue ought to be clarified along with simplifying the means of identifying the actual "corners" on the leech.

Tony Edwards wrote:On full size sails the pocket can stick out behind the leech. [...] A batten pocket is not the leech of the sail so presumably can extend beyond

Hi Tony

I'm guessing that, when you say "full size", you mean "according to the class rules of full size class XYZ". I guess most full size classes have class rules which over-ride the ERS in places.

For the IOM, this is the issue that I see, all quotes from the current ERS:

G.2.2 tells us that the leech is the aft sail edge. G.1.1 tells us that a sail includes batten pockets, reinforcement, stiffening, and so on. Hence, I deduce that the leech of the sail includes batten pockets, reinforcement, or battens. And that the shape of the leech therefore follows the shape of any of these things should they occur at the leech. As far as I can see, the IOM class rules give no dispensation for anything to project aft of a straight line between batten pocket points.

a holding patch at the inner end could be a "batten pocket patch"

As an aside, one of the little worms here is that a batten pocket patch under G.6.4 and G.6.2 needs to be no more than two layers of ply. Now ply is defined to be soft sail material at G.1.4(b), so a question arises whether these sticky-backed dacron patches we use are indeed plies of soft sail material. It would be helpful if an addition to the class rules explicitly permitted sticky-backed dacron as ply. Another aside is that sail materials in general are not specified. As before, we know this gives a problem with our closed rules, and it would also be helpful if an addition to the class rules could say that sail material is not restricted.

But relevant to our discussion is that, by my reading of the class rules, batten pocket patches are not permitted. IOM Class Rule G.3.1(b)(10) permits secondary reinforcement, but only as specified under IOM CR G.3.3. Going to IOM CR G.3.3, we see that only flutter patches are allowed; there is no mention of a batten pocket patch...

a "flutter patch" which under [IOM CR] G3.3 at 50mm could cover the end of the seam and by coincidence hold the outer end of the batten

Yes, except that, as above, I read ERS G.1.1 as including sail reinforcement, hence including the flutter patch, as part of the leech which shall not project aft of a straight line...

Yes but, no but, yes but!

In effect the concept of a batten pocket to locate a batten that can be interchanged or adjusted has never (to the best of my knowledge) been used on an IOM. So it begs the question why do we refer to a batten pocket at all - because once we do it needs definition.

To my mind the ability to easily define the "corners" of the mainsail leech is more important. Class Rule G.2.4 is already a bit of a nonsense for a measurer because a batten pocket under G.3.3. can be 25mm wide but the batten does not have to be in the centre of the pocket and could easily be say 5mm offcentre. So then the batten would not be on the leech corner but the centre line of the batten pocket must be.

All very confusing and as you say a bag of worms. Surely the test has to be if the Technical Chaps can manage an interprettation within the rules which we can follow. If not then the class must consider how to modify (and hopefully simplify) the rules. I suggest cutting out referrence to "batten pocket" would be a good start. Instead there needs to be a simple control of batten attachment.

Tony Edwards wrote:the concept of a batten pocket to locate a batten that can be interchanged or adjusted has never (to the best of my knowledge) been used on an IOM

Hi Tony

True, I've never seen a removeable batten on an IOM sail. But I have seen a number of sails which have batten pockets without any battens... I can't see any reason to remove the permission for batten pockets, some sailmakers like the 'soft stiffening' it provides. In any case, it isn't these which are causing problems.

A few quick notes--First, I do not believe the problem being outlined by Lester effects 50% to 80% of all IOM sails. I am certainly aware of one sail maker who used this "wrap around" system in the past, I don't know if anyone is using it in the present. Evidence?

Second, I am also not aware of any formal request from any NCA asking for an interpretation of this question. Nothing on this issue was passed on to me when I took on the VC Technical position, not sure where the assertion that this issue has been hanging around the Technical Committee since 2004.

Third, I think the problem has been identified, is there a rule change proposal and any NCA that would like to support it for the next AGM?

Fourth, any other issues? Please raise them here....

RoyL wrote:I am also not aware of any formal request from any NCA asking for an interpretation of this question. Nothing on this issue was passed on to me when I took on the VC Technical position, not sure where the assertion that this issue has been hanging around the Technical Committee since 2004.

Hi Roy

It'll be in the closed-to-Exec part of the forum, under Technical as I recall, but possibly under Measurement. Look it up there. You might think about asking Anders. The formal submission was made by the MYA.

A quick check found no formal submission on the records, only a discussion among then current members of the exec on rule changes they wanted to make.

Regardless, if an NCA wants to propose a rule change on this or any other issue, now is the time to bring it forward.