OKDIA to ban high modulus carbon??
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Robert Deaves has just alerted me to an article at http://www.okdia.org where they state that they are seeking a rule change to ban the use of masts containing high modulus carbon fibre. From the wording it looks like EXISTING MASTS could be banned! If you own a black stick you really need to read it or risk owning a £1000 linen pole!
Davebut only if built from hign modulus carbon, which is pretty unlikely, with one notable exception, that is not in this country.
This is not a really a problem for anyone yet. An arms race was developing in New Zealand and rather than let it continue until it was too late to do anything about it, OKDIA Technical Committee and OKDIA Executive stepped in and made an announcement with the sole purpose of curtailing the building of expensive masts using high modulus carbon.
As Dan says there is only one known mast that has been built from expensive materials so far and this is supposed to cost at least EUR 2500. All other masts should be unaffected by any new ruling.
OKDIA is taking advice and consulting mast builders on this matter and will publish their findings at a later date.
However if anyone has anything to add, then please use this forum. We are interested in sailor’s opinions on limiting materials used in masts, stopping an arms race, keeping the cost down etc.
The last thing that anyone wants is for the cost of masts to keep rising and rising.
Robert
Rob
This is an interesting topic as it brings to the top of the pile the ridiculous cost of OK carbon masts. £1,200 + for what is in effect a simple rig with virtually no real fit out i.e main halyard and thats it! Absolute madness!
Why is it then when I sailed Merlins I could buy a mast from S/Spar for£950 fully rigged which I think is a much more complicated rig, not only in terms of engineering but running and standing rigging as well?
I am delighted that the OKDIA has finally seen sense and blocked the arms race that was fast developing.
Lets hope that the cost of carbon rigs will no fall to sensible prices.
Richard
Richard,
I think that you are over simplifying the situation somewhat. It is because the OK mast has no shrouds that it becomes a much more complex spar to construct. It also uses 7.5kg of carbon as opposed to 3.5kg used in a merlin mast. It relies completely on the construction to give the correct Luff curve & sideways deflections.
On top of that everyone in the front of the merlin fleet are using Chipstow masts that cost closer to £2000. That said i am certainly not interested in the class entering a Hi-modulus arms race & the OKDIA announcement is absoultely the correct move.
The bottom line is that both Selden & Superspars will probably provide you with an OK mast for circa £800 today, but it won’t win you the worlds. The NZ ctech masts are less than £800, but you need to ship them which brings the cost up to about £1000.
It was inevitable that the masts would develop from the early days of carbon & that a few manufacturers would come out on top as supplying the fast kit. These masts are not made on production machines & consequently you have to pay for the labour.
The important thing is to make sure that we now stay in control & make sure that the prices don’t rise due to the use of more exotic materials. The rest is down to market forces. As long as there are 3 or 4 suppliers in the mix prices should stay under control. I think £1000 for a mast is quite reasonable relative to £600 for a sail which won’t get you through 2 seasons. We used to pay £600 for the metal masts.
Thats my opinion, for what its worth.
TerryTerry,
That is a very valid and worthy opinion you have made. You are quite correct I had wrongly simplified the situation somewhat, if anything because I didn’t know what the heck I was talking about! I didn’t like to mention the Chipstow mast at £1,200 either!
You mention that “Selden & Superspars will probably provide you with an OK mast for circa £800 today, but it won’t win you the worlds” what is wrong with Proctor & S/S masts for OK’s? Not that I would buy a carbon mast at the moment as it would not make economical sense given the age of my boat, but are there issues with bend characteristics etc on these brands as opposed to Ceiledh, Williams etc?
All the best
Richard
Richard,
The Procter mast have a habit of snapping at deck level, which is slow. It is not really due to the construction of the tube but rather poor engineering whne they sleeve them.
Because of the production spinning equipment they have, the masts can be produced quite cheaply but they can’t get the bend right in the top sections because the mast diameter is too big. They are very powerfull in mid range conditions, but anything above F4 & you cant dump the power. The SS masts use production spun tapered tube from NZ & basically glue the sections together. i had one that worked pretty well, but i had to re-make most of the fittings because they fell apart. Construction was poor, but the general bends were in the right ball park & the mast is still standing today.Terry
It’s not just a kiwi issue or just one mast….don’t you guys realise Ceilidh masts have M40J high modulus carbon in them and so would be banned as well? A lot of you have these masts.
The current thinking as I understand it is not to ban high modulus carbon material but to place a limit on the maximum allowable modulus allowed. The thinking is also to place a limit on the amount of the high mod carbon you are allowed to use eg 25% per mast. I believe placing a limit on the modulus is a good idea to keep costs down, an acceptable limit may be 385GPa, this would mean M40J material which has a modulus of 372GPa would be allowed ie Ceilidh masts become legal again. I do not believe placing a limit on the amount of the stuff you use is a good idea for the following reasons-
1) It is unenforcable, who can tell looking at a mast how much carbon of a particular grade is in it? Furthermore even if masts are certified by their manufacturers as having the specified level what is to stop someone purchasing some more high mod carbon and resining it to their mast to stiffen it further? It’s easy to do.
2) We already have quite stringent class rules regarding weight, c of g, and minimum allowable mast dimensions which effectively limit the amount of high mod carbon you can use anyway. ie a mast made entirely of high mod carbon to the allowed minimum section size would be too light, and attempting to bring it within 600g of the 8kg limit through the use of huge/heavy steel base plugs and/or gooseneck fittings would result in the c of g being too low.There appears to be a general feeling out there these masts will be too expensive based on the rumoured cost of one NZ manufacturer. This appears to have sparked the entire controversy off. Raw materials prob make up 30% of the mast price, from reading I’ve done high mod carbon is approx 4x the cost of standard mod and 2x the cost of intermediate mod carbon. Considering a legal mast can not be entirely made from high mod carbon the raw material cost increase is likely to be small. If one company then wants to overcharge for masts containing high mod carbon then let them, they will ultimately just be undercut by others.
My 2c worth.
Hi Karl
Can you explain why manufacturers would use high modulus carbon fibre?
It obviously puts their costs up and getting a lighter mast isn’t allowed under the class rules, so what’s the point in using it?
DaveHigh mod carbon allows you to make a mast section down to the smallest allowable section size which is sufficiently stiff. To do that with say standard mod carbon the mast walls would be very thick and the mast may end up over weight. A small section size= less drag= smaller zone of wind turbulence behind the mast.
Higher mod material also has better dynamic response ie the mast responds more quickly to gusts. However at the level this material can be used (with regard to class rule restraints pointed out above) I really don’t think a high mod carbon mast (say 30% high mod, 70% std/int mod mix) would exhibit dynamic properties significantly different to say a mast made from a mixture of standard and intermediate modulus carbon.
The use of high mod carbon also gives you a little more freedom to engineer certain bend characteristics into your mast that were previously difficult to achieve.
These are the advantages as I see them.
Thank you. It seems to me we really need a rule giving a minimum mast diameter: that way high modulus carbon would be less attractive and we’ve got a parameter we can measure. I can’t personally see any point in a rule about %ages of material. Once the mast’s made, who knows what went into it?
Dave
@davecooper wrote:
Thank you. It seems to me we really need a rule giving a minimum mast diameter: that way high modulus carbon would be less attractive and we’ve got a parameter we can measure. I can’t personally see any point in a rule about %ages of material. Once the mast’s made, who knows what went into it?
Dave
We already have a minimum section size….and yes I agree about the percentages….totally unenforcable and would leave evryone asking a lot of questions of a fast boat
If many masts are impacted this unilateral banning by OKDIA does not seem a particular fair way to deal with a problem that has not been properly presented to the membership of the Class – I heard nothing in Poland anyway.
Fundamentally I do not understand how a mast could be tested for high modulus carbon. Unless a sensible test is available – if it is can someone explain – then the proposed rule must be a waste of time.
Hope this can get sorted out soon, and I hope that the Class is liasing directly with mast builders around the World so as to have a constructive dialogue on this.
In principle keeping costs down has to be a good idea.
John
There is absolutely NO intention whatsoever to ban ‘many’ current masts. If we have to ban one then, in my opinion, that is one too many.
This issue arose after Poland when OKDIA was advised that people were about to spend £2000 on masts constructed from high-modulus carbon. OKDIA took the only action it could to stop this happening, which most people agree was the proper thing to do. What comes next is down to the Technical Committee. However, any proposal or rule change it presents (even if it is brought it on emergency measures) will have to go to membership for approval at the next AGM.
OKDIA is talking to all mast builders to gather information and advice on the best way forward. There are a lot of varying opinions on what this is.
Even if we cannot test for high-modulus carbon (as far as I know there is no way to test), the onus is on the mast builder to build within the rules and he knows he will have a lot of problems if he is found breaking them. Cheats will always cheat, but I trust there are none in the OK class.
Now for some this is not good enough, and they will say we must have a rule that can be tested. But if the only option to limit price increases is to have an untestable rule set in trust, then perhaps that is the way to go. (One other option apparently is to change the dimensions of the mast to negate the effect of using high modulus, but that’s a whole different kettle of fish.)
Robert
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