Statement Re UHM Carbon in Masts

[Chris Perry]

Just Noticed this on OKDIA website, not sure if this affects any current masts or any planned masts but thought it was worth bringing to folks attention.

Statement on the use of Ultra High Modulus Carbon in masts
18. January 2012

Following recent developments in the Finn Class, the OK Dinghy Class may soon be faced with the prospect of Ultra High Modulas carbon being used in their masts and the increased costs that go with it. This is a situtaion that the Technical Commitee feels would be bad for the OK Class and also for the mast manufacturers.

The Technical Committee has been working for some time to find ways to stop this.
A year or so ago the OK Dinghy Class approved a rule change to ban the use of carbon with a modulus higher than 400GPa in their masts. This rule was proposed to ISAF, which subsequently rejected it on the basis that it is unenforceable because only destructive testing could be used to check what is in a mast and they felt that this would be unacceptable to the sailors.

ISAF suggested that the only way forward was to introduce a scheme of licenced builders. We are now working with ISAF and looking at ways to acheive this. We realise that this would be a big change for the Class but feel that it is the only option. However, any Rule change must first be passed by the AGM and then ratified by ISAF.

At the time that the Rule change was rejected by ISAF, the infomation we had recieved from various experts was that UHM would not work in unstayed masts because it was too brittle. But as just mentioned, recent developments from the Finn Class have outdated this infomation.

As a class, we feel that it is beneficial, both to the Class and the mast manufacturers not to use UHM, and so we would ask everyone to please refrain from using it until we can get Rules in place to ban it. If and when this Rule change is passed, the intention is that all masts must conform, whether built before or after the Rule change. We feel that expensive masts, and in fact any developments that allow a few sailors to gain an advantage at large cost, are bad for the future of any class and their gear suppliers.

Thanks you for your cooperation and please let me know if you have any comments or thoughts.

Alistair Deaves
Chairman – International OK Dinghy Technical Committee

[X]

All,

This probably needs some context.

There have been recent developments in the Finn Class moving to UHM Carbon – This has increased the cost of the spars to around £7000. Clearly we don’t want this kind of development in the OK. Indeed i beleive the recent shift to HM Carbon has already damaged the class by adding £1000 to the cost of a new boat.
To date neither C’tech’ , Celidh or AAdvark have produced any masts for the OK using UHM. The TC have asked them not to do so and have identified that the class is working with ISAF on a licensing rule for its spar makers to ensure the modulus is limited to the current materials. Any UHM masts that are built will be ruled out of class and the 3 main builders have agreed to follow the TC’s request.

net: There is no concern for anyone in the UK regarding a mast they are currently using and there should be no concerns that any mast that might be on order will be outclassed before it even arrives.

hope that helps

Terry

[Si Cox]

Interesting. It does seem to be a weird way of regulating masts. I am sure the cost and supply of carbon masts for the OK is holding the class back – perhaps in the UK more than in other countries. But the current pricing of masts built in the UK seems reasonable for an unstayed mast which is customised to the sailors requirements. We businesses need to make a profit afterall!

Some classes that are keen to ensure that they are reasonably priced, such as GP14’s and Firefly’s, have their general committee set the maximum cost of sails. Surely this would be the most sensible solution for the OK masts? If the TC decided that the maximum price for a mast was, for example, 1500 GBP (allowing for exchange rates and excluding shipping etc) then this would allow all existing standard and high modulus masts to be legal and would ensure that the manufacturers didn’t develop high spec masts. Perhaps the prices should be even lower to ensure that all masts only use standard modulus carbon? This could be reviewed annually. The sailors could then keep receipts for their masts with their certificates – or a copy be sent to the class measurer and a measurement label sent to be applied to the masts.

[Chris Perry]

Thanks for the background Terry,

I suspected that this might be a price related thing and £7k for a mast is somewhat extreme, but then again given the financial benefits an Olympic medal would bring to the sailor, I can kind of understand where it comes from.

We dont want an arms race in the fleet, epsecially in the current financial climate ( or indeed at any other time for that matter) and a set of rules that makes it more one design and limits costly development can only be a good thing.

Catch up with you when the season starts.

Cheers

Chris

[NickCraig]

Totally agree with everyone on this, sensible proposal from Alistair

Though think ISAF should have accepted the proposed rule. They’re right it is hard to enforce but so is testing for a a boat with a load of carbon in it but we still have the rule so people know it’s illegal so don’t bother

Cheers
Nick

[burt]

good decision dont want to effectivly double the price of new boats now would make the class so unattractive (cost wise) compared to (dare i say it) a solo!!!

good work tc

[davecooper]

Can anyone explain what the advantages of using uhm carbon in a mast are, as long as the weight and c of g height are controlled?
Dave

[alistair]

Well to be perfectly honest we don’t actually know if there would be any advantage over the current masts.
UHM is a lot more expensive and masts made with it may be more dynamic and may have a similar increase in performance that we saw when the first hi-mod masts came out.
But one thing we are quite sure about is that we don’t want to take the chance of that being the case.

[davecooper]

Thanks Alistair, that’s about what I thought. Actually, we don’t even know that the (apparent) improvement with the hm masts was actually due to the use of hm carbon, or just whether it was a better design. I dunno, we never had this trouble with wood!
Dave

[andyt15064]

Keep up the good work Alistair. I fully support the direction your are taking and it’s good to have some leadership from the TC.

Dare I say it but personally I think even the whole HM thing is a bit “Emperor’s New Clothes” (someone explain that to Burt please). I’ve got a 2007 (LM or MM? – not HM anyway) C-Tech which is excellent across a range of wind strengths with a P&B or Quantum sail, particularly on flat water. I tried Pete’s 2010 HM C-Tech mast out at Largs open meeting last year and went much slower. Similarly I’m very happy with my Alex Scoles Rushworth shape hull and certainly wouldn’t consider swapping it for an Icebreaker shape.

Is there a mast that conteracts the ageing process?

Andy

[Mike Edwards]

I think it was a big mistake to allow HM let alone UHM. Lots of people within the class could not afford to buy a carbon mast when we first moved in that direction, with many having to save up and wait for a second hand one to come on the market (I do though think it was the correct decision to move to carbon) To then find that the goalposts had moved again to allow HM did not go down well with many………including me! Not forgeting those people still sailing around with needlespars, who now found themselves even more removed from the best kit in the fleet.

We need to make it as cost affective and as easy as possible for people to take up OK sailing and to become and remain competitive. I welcome us having control over builders of boats, masts and sails, as this should deter the few in the fleet who try and push the bounderies in searh of glory with little regard to cost.

Cheers
Mike

[hughsheehy]

On a related topic…

I saw recently someone selling a Finn mast on the basis that it could be cut down and used on an OK. It was a carbon Finn mast.

Is this legit?

H

[burt]

I think dave has one seems quite good

and you right andy that does need to be explained!

[NickCraig]

yep totally agree!
Hugh – I think a Finn cut down mast is legal as long as it meets OK class rules and can be a cheap way to get a decent mast given how far Finn technology has moved on

Dave – you’re right UHM couldn’t change the mast weight or c of g. But being dynamically more responsive could make a huge difference. It would either mean a mast that is much faster through waves & chop upwind. Or you could go with a mast that is much stiffer on land but with the greater dynamism works as well as a normal HM mast in breeze so the stiffer UHM would be much faster in lighter airs. Finding a middle ground between these 2 advantages would result in a potentially much faster mast in all conditions.
Not what the class needs given the cost…the OK seems to be doing really well in the UK with good quality, low cost one design racing being the key to that.

Cheers
Nick

[andyt15064]

No need to cut down the Finn mast – just bring the measurement band down to the right height. i seem to remember a guy at Medemblik with half a metre of spare mast sticking out at the top! Dave goes fine with his Finn mast.

Andy

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