Jump to content

Should there be a change to the Marblehead Class Rules relating to sail thickness?


Recommended Posts

On the Marblehead Class website there has been a question asked by the IRSA technical officer.

This has prompted a request for the skippers globally on the desire, or not to consider a change to this rule.

Please visit the Marblehead Class website and post any comments here.

The post on the class website can be found at: https://marbleheadsailing.wordpress.com/

 

Link to post
Share on other sites

I don't think it's the thickness of a sail that's the issue, it's the flexibility of the material that matters.  Of course thickness is much easier to measure but it's hard to come up with a good rule that is based on measuring the wrong parameter.  If rule changes are being considered then we should also look at the term 'soft sail'.  From an engineering standpoint, softness (cf hardness) is the resistance of the material to compression, not how easily it bends.  For example, sponge rubber is soft, diamond is hard.  If we do want to limit the stiffness of sails then the rule should state what the maximum bending stiffness should be.  

Many years ago (40 odd?) a read an article on the development of padded sails i.e. two sails with a thin layer of shaped foam between them.  I don't think the idea worked but it is interesting to consider whether such a sail could be described as soft, it would certainly be described as thick.  It's also intersting to note tht the idea has re-surfaced (in a slightly different form) on the current AC75s.

Link to post
Share on other sites

This discussion from the IRSA is  about battens and not, strictly speaking, sail thickness. Not to disagree with John's engineering analysis it is worth pointing out that the term "soft sail" is defined in the ERS issued by World Sailing as:- 

A sail where the body of the sail is capable of being folded flat in any direction without damaging any ply other than by creasing.

The discussion is laid out on the M Class website so suffice it to say that there appear to be 3 options available with regard to the current batten rules for M and A class yachts.

1) Do nothing and see what happens, but this could lead to further requests for interpretation and/or protests at a major event.

2) Change the rule somehow to prevent "soft sail" material being used as a batten and bypassing the rules. A potential minefield, especially for measurers.

3) Take away the rule altogether

This discussion does not apply to the 10R class as they have no batten restrictions, and where no abnormal sails have appeared as a result.

Link to post
Share on other sites

You are a farmer that has an incredibly small hole in your fence pointed out to you. The hole is in an area that has caused no bother or problem for 30+ years by being largely unvisited, with your fence continuing to do its job in protecting your livestock.

Your solution is to remove the fence as a favoured option?
Would this not cause more problems than a small repair to the fence?

Surely the first priority of any governing body is to protect any class from change, more so change that is entirely unnecessary with an outcome more likely to increase cost and disenfranchise current owners and supporters. Sadly such changes are becoming all too common with those that control and steer our classes.

There is a simple solution if common sense is applied to any problem. In this instance, a simple panel weight/thickness differential tolerance limit on the body of sail construction could be added as an amendment to existing class rules. This means nothing changes and we move on collectively, continuing to follow the class rules as we have done for so long.

Removing current restrictions on battens and placement will alter sail construction on sail plans loaded with high point areas on the leech. Arguing that this could have happened to date in hypothesis is just nonsense. It hasn’t so let’s deal with reality! Suggesting a crossover from the 10R class is relative is not quite correct given the sail plan restriction and platform over a free for all in 10s where load points are minimised through sail design.

Nothing hurts open classes more than needless constant rule change. Such changes are seldom geared to make our classes cheaper, more accessible or easier to transport. It would make a pleasant change if the time spent looking to make changes was used in a positive way that protected and helped our classes. It can be done if you try...

 

 

 

 

Link to post
Share on other sites

Brad makes an interesting statement which is worth considering in more detail:

Quote

Surely the first priority of any governing body is to protect any class from change, more so change that is entirely unnecessary with an outcome more likely to increase cost and disenfranchise current owners and supporters. Sadly such changes are becoming all too common with those that control and steer our classes.

Marbleheads (and As) are not one designs so change is supposed to happen slowly over time.  Marblehead design has changed beyond recognition over the years with the result that (most) boats over 15? years old are totally uncompetitive against modern designs.  Allowing change lets the class evolve and remain viable in performance terms against current designs.  The price you pay for this is that older designs are not competitive, so older (and cheap) 'beginner boats' are not really worthwhile and attracting new sailors to the class becomes difficult i.e. expensive.  

What is needed is evolution not revolution so that existing boats / designs are not suddenly put at a disadvantage.  As an example, suppose the rule on battens was removed and someone developed a fully battened sail that was significantly faster in high winds, say.  Then every serious Marblehead racer would have to go a buy a new fully battened sail.  This is not what we want to happen.

In a development class the rules are used to prevent development in an unwanted direction such as cost (e.g. banning gold keels) and practicality (e.g. mast height). If the above premise is accepted then the rules (concerning the design of boats) should change for one of two (and only two) reasons:

1) To ban a development that has been shown to be a significant advantage, but is unwarranted for reasons of cost, practicability, safety or accessability.

2) To allow a previously banned development that would now reduce cost or increase practicability, safety or accessability.

An example of the latter might be 'First Person Video' which could become so cheap as to not be a cost factor and may encourage more people to take up the sport.

Applying these rules suggest that the batten rule should not be changed unless and until someone demonstrates that there is a significant advantage to be gained by 'bending' it AND we, as a class, decide that there are good reasons for NOT allowing it.

 

 

Link to post
Share on other sites
45 minutes ago, John949 said:

Marbleheads (and As) are not one designs so change is supposed to happen slowly over time.  Marblehead design has changed beyond recognition over the years with the result that (most) boats over 15? years old are totally uncompetitive against modern designs.  Allowing change lets the class evolve and remain viable in performance terms against current designs.  The price you pay for this is that older designs are not competitive, so older (and cheap) 'beginner boats' are not really worthwhile and attracting new sailors to the class becomes difficult i.e. expensive.  

What is needed is evolution not revolution so that existing boats / designs are not suddenly put at a disadvantage.  As an example, suppose the rule on battens was removed and someone developed a fully battened sail that was significantly faster in high winds, say.  Then every serious Marblehead racer would have to go a buy a new fully battened sail.  This is not what we want to happen.

Good points John but in the case of the M class I could suggest that it has been shown that there are more than a few older designs well past 15 years of age that with minimal upgrades are more than competitive. This to me shows a well written set of rules that need to remain true, not just thrown open when a perceived problem is sought or found.

Evolution, not revolution is spot on, but to protect not only the past and present, but also the future.

Having only ever raced Open or unrestricted classes, it becomes more clear over time that when greater freedom to rule sets are proposed, that there is either a lack of thought or consideration given to any downside to a class. Such changes rarely ‘if ever’ result in cost saving but usually the opposite. Whether that is the aim of these continued type of unnecessary and bold changes by those that support them is not for me to say....

Edited by Brad Gibson
Link to post
Share on other sites

For the record the following is what I replied to the IRSA TC with my SAILSetc hat on:

Some of the ‘sail’ materials I have used are thicker than some of the ‘batten’ materials I have used. So it is easy to see that there is a potential problem for measurers as well as sail makers.

I suppose there are three basic options:

1             Do nothing – we are aware of the situation and choose to do nothing on the grounds that it is not a problem now, therefore will not be a problem in the future, and if there are un-desirable consequences because we did nothing we are prepared to accept them. An example of doing nothing (but not knowingly) was failing to introduce a draught limit in the Marblehead and Ten Rater classes when the depth chosen would have been considerably lower than the figure we currently have. This was further exacerbated by failing to propose an alternative to the limit that was introduced. Had a lower limit been chosen at an earlier stage then more venues, in the UK at least, would have remained capable of sustaining racing for those classes and the level of technology/craftsmanship required to build top quality fins would be considerably lower thereby enabling more builders to be successful. The boats might have been 0.1 knot slower but that would make no difference to the level of competition enjoyed in the classes. Perhaps this matter is not in the same league but it illustrates possible consequences of not taking action at an opportune time. What’s the worst that can happen? In this case it may be nothing more tedious/serious than spending a lot of time interpreting the class rules after something contentious, maybe at a major event, and wasting a lot of racing time for everyone. And maybe putting a number of sails out of class.

2             Do something to preserve what we consider to be the intent of the current class rules to keep the sails as they are now – this would involve limiting the thickness of the material used for the body of the sail in some way, limiting the size and placement of reinforcement, and trying to discriminate in a way that is more meaningful for rc boat sails between soft sail material and stiffening. The last of these three may be difficult or impossible leaving us with more complex class rules which still do not work. That would bring us back to where we are now. Is there any viable proposal that would appeal to a majority and not offend anyone? Given that no-one likes longer, more complicated, rules either this does not seem likely. Another consideration with this approach is that existing sails would have to be grandfathered and it may not be possible to replicate them in the future.

 3             Do what you (that is Robert Grubisa/IRSA TC) propose – the class rules and measuring, became simpler and shorter. It is what the 10R class did decades ago and the class did not die, the end of the world did not come. Sails, especially for lower rigs, are probably better and longer lasting than they would be otherwise. Certifying them is a doddle.

Other reasons for relaxing control of stiffening

Historically battens were used to flatten the leech and then extend the roach width, and therefore to gain sail area, when the sail materials themselves were incapable of such shapes without the presence of stiff supporting battens. At that point, if sail area should continue to be controlled, it became necessary to restrict either the width of the roach and/or the length of the battens. Some classes used both controls. However, as the control of sail area itself in the M and A Classes is well established, and we have a vast range of sail materials of different inherent stiffness, it hardly makes any sense to continue to limit (and continue to measure) something that is widely acknowledged to be of little importance. So why not stop limiting and measuring the battens?

The argument has been made that perfectly good sails can be built without battens of any sort. So why bother to count or otherwise restrict battens?

Full length battens are already permitted in A Class headsails and are rarely used. Clearly changing the rules will not change anything there.

Anyone who is entirely happy with the sails they make now, or the sails they own, under the current restrictions will not feel prejudiced by the relaxation proposed. If there is a perception that existing sails are not as good as they would have been had they been made to more relaxed rules, then it would be easy to ‘up-grade’ them.

The only danger I can foresee is that sails made with a large number of full length battens (which are therefore more costly) are used successfully, but themselves are of no particular benefit. In this case there may be a tendency for them to become fashionable thereby increasing the cost of sails un-reasonably. However, as this seems to be permitted now, and it is not happening now, and there may be no way of preventing it in the future, I see nothing to be concerned about here.

Take care,

Graham

 

Link to post
Share on other sites
22 hours ago, Graham Bantock said:

For the record the following is what I replied to the IRSA TC with my SAILSetc hat on:

Some of the ‘sail’ materials I have used are thicker than some of the ‘batten’ materials I have used. So it is easy to see that there is a potential problem for measurers as well as sail makers.

I suppose there are three basic options:

1             Do nothing – we are aware of the situation and choose to do nothing on the grounds that it is not a problem now, therefore will not be a problem in the future, and if there are un-desirable consequences because we did nothing we are prepared to accept them. An example of doing nothing (but not knowingly) was failing to introduce a draught limit in the Marblehead and Ten Rater classes when the depth chosen would have been considerably lower than the figure we currently have. This was further exacerbated by failing to propose an alternative to the limit that was introduced. Had a lower limit been chosen at an earlier stage then more venues, in the UK at least, would have remained capable of sustaining racing for those classes and the level of technology/craftsmanship required to build top quality fins would be considerably lower thereby enabling more builders to be successful. The boats might have been 0.1 knot slower but that would make no difference to the level of competition enjoyed in the classes. Perhaps this matter is not in the same league but it illustrates possible consequences of not taking action at an opportune time. What’s the worst that can happen? In this case it may be nothing more tedious/serious than spending a lot of time interpreting the class rules after something contentious, maybe at a major event, and wasting a lot of racing time for everyone. And maybe putting a number of sails out of class.

2             Do something to preserve what we consider to be the intent of the current class rules to keep the sails as they are now – this would involve limiting the thickness of the material used for the body of the sail in some way, limiting the size and placement of reinforcement, and trying to discriminate in a way that is more meaningful for rc boat sails between soft sail material and stiffening. The last of these three may be difficult or impossible leaving us with more complex class rules which still do not work. That would bring us back to where we are now. Is there any viable proposal that would appeal to a majority and not offend anyone? Given that no-one likes longer, more complicated, rules either this does not seem likely. Another consideration with this approach is that existing sails would have to be grandfathered and it may not be possible to replicate them in the future.

 3             Do what you (that is Robert Grubisa/IRSA TC) propose – the class rules and measuring, became simpler and shorter. It is what the 10R class did decades ago and the class did not die, the end of the world did not come. Sails, especially for lower rigs, are probably better and longer lasting than they would be otherwise. Certifying them is a doddle.

Other reasons for relaxing control of stiffening

Historically battens were used to flatten the leech and then extend the roach width, and therefore to gain sail area, when the sail materials themselves were incapable of such shapes without the presence of stiff supporting battens. At that point, if sail area should continue to be controlled, it became necessary to restrict either the width of the roach and/or the length of the battens. Some classes used both controls. However, as the control of sail area itself in the M and A Classes is well established, and we have a vast range of sail materials of different inherent stiffness, it hardly makes any sense to continue to limit (and continue to measure) something that is widely acknowledged to be of little importance. So why not stop limiting and measuring the battens?

The argument has been made that perfectly good sails can be built without battens of any sort. So why bother to count or otherwise restrict battens?

Full length battens are already permitted in A Class headsails and are rarely used. Clearly changing the rules will not change anything there.

Anyone who is entirely happy with the sails they make now, or the sails they own, under the current restrictions will not feel prejudiced by the relaxation proposed. If there is a perception that existing sails are not as good as they would have been had they been made to more relaxed rules, then it would be easy to ‘up-grade’ them.

The only danger I can foresee is that sails made with a large number of full length battens (which are therefore more costly) are used successfully, but themselves are of no particular benefit. In this case there may be a tendency for them to become fashionable thereby increasing the cost of sails un-reasonably. However, as this seems to be permitted now, and it is not happening now, and there may be no way of preventing it in the future, I see nothing to be concerned about here.

Take care,

Graham

 

As many of you will know, i'm not an active owner of either of the classes that this discussion could possibly affect.

However, with over 24 years sailmaking experience and with a decent understanding of ERS from full size classes perhaps my thoughts might give an unbiased view from someone that does not have a commercial or financial interest in any outcome.

1             Do nothing, the good news here being that whilst some might think there is a loophole, no commercial supplier has tried to exploit this loophole. This either means that Commercial suppliers have not given any such loophole thought, have thought about it but decided that it is not in the spirit and intent of the rules or have tried it and been unconvinced by any benefit, all good stuff however once the seed has been planted with a loophole as in this case you can bet your bottom dollar that suppliers will try their upmost to gain an advantage, nothing new there, therefore moving forwards doing nothing is probably not an option.

2            Change The Class Rules to preserve the intent and spirit of the current class rules, This is exactly what should be happening, measuring thickness is commonplace in many full sized one design classes, is it difficult? No, bearing in mind measurer's for full size classes will be measuring ply thickness from light weight nylons, woven polyester & paneled laminates, i'd suggest measuring ply thickness for RC classes is going to be easier than full size classes, this would need to be worked in conjunction with Primary and secondary reinforcement size, with thought and discussion with commercial suppliers to find common ground as to current materials in use and a workable rule moving forwards.

From my understanding after discussion with five RM measurers you require a PHD to navigate the RM measurement spreadsheets so measuring ply thickness should be a walk in the park.

3             Do what you (that is Robert Grubisa/IRSA TC) propose, If you follow Formula 1 i'd use this scenario as like using a new version of car, everybody hopes it has a beneficial affect, evens the playing field, makes measurement easier, better following, for fans etc.... The reality has always proven to be the polar opposite, one constructor gets it spot on whilst the rest of the field plays catch up!

Graham mentions lifting restrictions would bring the RM in line with the 10r, funnily enough the use of full length battens in a 10r mainsail was not used as an example however seems commonplace on smaller rigs with a pocket luff, those full length battens are obviously there for a reason!

Therefore it would be naive to suggest loosening the rules would have little affect on performance.

In fact, if you were to use full length battens i'd suggest the sail body can be of lighter material(s) leading to obvious gains.

Summary

The loosening of class rules to allow full length battens or more battens will lead to development, unfortunately development will cost class skippers money, an arms race where there has been continuity. 

That would seem a complete nonsense to me where class rules can be changed to preserve the current intent.

 

Link to post
Share on other sites

It's always good to have knowledgable input into these discussions and this topic, with the exception of myself, seems to have generated just that.

As a slight aside from the main discussion

11 hours ago, Gavin Watson said:

From my understanding after discussion with five RM measurers you require a PHD to navigate the RM measurement spreadsheets so measuring ply thickness should be a walk in the park.

I am a measurer for the M (and 10R and IOM) class and was educated in the pre computer era and didn't gain a PhD and yet I have no problem at all with the measurement spreadsheet. Maybe I am just fortunate to have had excellent training from an experienced measurer and enjoy regular sessions with a couple of other local measurers where we check each other and compare notes. But then training is a topic for a whole new thread.

Link to post
Share on other sites

As it was not made clear from the outset, MYA owners/skippers of both the A and Marblehead classes should share their direction on how they wish to go on the above proposed changes ASAP. This can be done by contacting the MYA International Officer Phil Holliday by email at: chair ‘at’ mya-uk.org.uk  or posting here.

Any MYA position on this will then reflect the feelings of owners when forwarded to IRSA on our behalf.

To do nothing only leaves the future direction of our classes to others that may or may not have your interests at heart dependent on your viewpoint or hat worn.

 

Link to post
Share on other sites

Sorry to bang on about this but a sail thickness rule will not stop fully battened rigs or indeed other areas of local stiffening.  If you didn't like my appeal to the science of measuring the wrong parameter, here's a guide on how to make a fully battened rig with a sail thickness rule in place.

The most simple rule would be ' The sail thickness shall not be greater than X'.  Fair enough, but does this apply to seams?  

If it doesn't, then one simply creates seams wherever one wants to create stiffening and 'hides' a piece of stiffening material in the seam.

If it does, then what is the value of X? If it is an actual value then it has to be large enough for two layers of the thickest sail material that will be allowed plus a layer of double sided tape or whatever to join the sail.  So if I use relatively thin material thin material then I have plenty of spare width to include some stiffening material as well.  I can see a market opportunity in really thick stiff double sided tape.

Something like 'The seams shall be no thicker than twice the thickness of the thinest material plus X' where X is a reasonable width for double sided tape.  This is better. but what about stitched seams? The minimum thickness now has to allow for two thicknesses of material, plus the double sided tape, plus two thicknesses of the thread.  Sails are normally sown with a swing stitch so there must be an allowable width of stitching; so instead of using a swing stitch, sew two parallel lines of straight stitch and fill the gap with the batten material.

And so it goes on.  There are also issues with scrim sails and sails made of two different thicknesses of material (perfectly legal at present) which give yet more scope for producing local stiffening and still meeting any thickness rule.  A scrim sail made with 'stripes' of wider, stiffer 'thread' material looks interesting.

Now you may be thinking that some of my suggestions break other rules that already exist, but that is the whole point of the argument.  If we already have rules that prevent local stiffening then we don't need an additional rule.  If we don't have such rules then a sail thickness rule doesn't prevent local stiffening.  My contention is therefore that a sail thickness rule is either redundant or ineffective and therefore should not be considered.

P.S. I made a jib this afternoon and used 'finger style patches to reinforce the tack and the clew.  Quite by chance, as the jib was quite narrow, the patches actually overlapped slightly (on opposite sides of the sail) so I accidentally created a sail with full width additional stiffening across the foot.  Is this legal?  If you think it shouldn't be then how could you write a sail thickness rule that prvented it?

Link to post
Share on other sites

On the subject of soft sails:

Quote

A sail where the body of the sail is capable of being folded flat in any direction without damaging any ply other than by creasing.

This is a terrible definition.  What does flat mean in this context?  One can fold something over so that the top surfaces are parallel (into a U shape) but still leave quite a big gap between the two surfaces, is this flat?  Surely creasing is damage (local yeilding for any metallugists). How is a measurer supposed to determine if the material has been damaged if visible changes to the material are allowed but invisible ones (e.g. microscopic cracks) aren't.  Just to put the tin hat on it, what does 'ply' mean in the contect of a hetrogenous material like mylar film or a plastic batten material? If the material doesn't have ply's then, as written, the material can break and still pass the letter of this test.

Sorry I'll shut up now.

Link to post
Share on other sites
1 hour ago, John949 said:

On the subject of soft sails:

This is a terrible definition.  What does flat mean in this context?  One can fold something over so that the top surfaces are parallel (into a U shape) but still leave quite a big gap between the two surfaces, is this flat?  Surely creasing is damage (local yeilding for any metallugists). How is a measurer supposed to determine if the material has been damaged if visible changes to the material are allowed but invisible ones (e.g. microscopic cracks) aren't.  Just to put the tin hat on it, what does 'ply' mean in the contect of a hetrogenous material like mylar film or a plastic batten material? If the material doesn't have ply's then, as written, the material can break and still pass the letter of this test.

Sorry I'll shut up now.

SoftSail
It is normally quite easy to establish if a sail is soft without having to fold it and risk "damaging the ply". However, in cases of doubt, if it is claimed that the sail is soft, a measurer should fold the ply, usually in an area of secondary reinforcement. If the measurer is unable to flatten the ply when applying pressure between forefinger and thumb or the sail suffers damage more than a crease line, then the sail is not soft.

Link to post
Share on other sites

I very much like Brad's analogy to the hole in the farmer's fence.  The hole must be so small that I am now unable to find it after 60 years of looking when making Marblehead sails!  Brad is also absolutely right that class rules should not be changed unless it becomes absolutely clear that there is some advantage be gained from a particular rule.  Trying to cope with 'what ifs' just makes rules more complicated for something that may never happen.  There have never been any rules about sail construction until we adopted the ERS when even then the single simple sail construction rule is that it has to be a "soft sail", which continued the understanding of the class tradition in the 70 years before that.

 

The only thing I wasn't happy with in Brad's piece was the proposal to introduce a new rule on the question of setting a notional proportion of sail and batten thicknesses. So what if the sailcloth or the combination of layers is stiffer than the batten? Currently the rule doesn't restrict the thickness/stiffness of sailcloth which removes the need for battens if you really want such a stiff sail. Currently this is of no consequence, so there is no need to introduce another rule, firstly because this is a change to the class rules which is hated by measurers and owners alike and secondly from a practical point of view it requires more work to be done by the measurer for each sail which could be up to 18 Marblehead sails! 

 

In both A and M classes the battens serve an important purpose to define the shape of the leech so unless we want a big change to redefine these shapes we should stick to the traditional sail shapes set by the battens and leave the class rules alone.

 

If we put the magnifying glass away should we not take a wider view of the Marblehead class?  In order to improve its popularity and make it less expensive, wouldn’t the best rule change be the reduction in the number of rigs?

Link to post
Share on other sites

Well said Roger!

To be clear on any suggestion I had made to a rule by amendment, my thoughts are that if through IRSA’s say so, that we need to better define how we remain the same as what is near 100% widely accepted at present, then that can be done with maximum tolerance differences of sail body material weights or thicknesses. This would definitely be more favourable than just removing restrictions entirely which I feel we both agree.

I agree entirely regarding how our IRSA TC and influential members within could be far better to focus on real issues that would make our classes more attractive with a halt put on cost increasing rule changes. To do that though would be to see the sport through the eyes of all owners, both current and prospective.
Given the increased level of commercially interested parties that sit on and control our rule committees within IRSA, IOMICA and many NCAs across the world, can we see this happening any time soon to alter recent trends and return some balanced focus on what is real to owners that ARE the classes?
 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...