In commenting on various post I will switch roles from time to time. Some comment I make as a chairman of the F16 class and others as a private F16 sailor. Yet others again as a proxy for Greg Goodall as he is unable to reply himself with current preparation for the F18 worlds that is on within a week or so.

I will denote my role by naming it between accolades.

I will give a few quick replies to your points steve.


>>Regarding the carbon beam issue (Part 2) I think it could be re-evaluated if carbon beams become cheaper in the future, however this will always be region-specific.

(private sailor) This is the case with the non carbon beams proposal but the proposal regarding permanently fixed beams remains unaltered by the fact wether carbon is inexpensive or not as this proposal it fully driven by transport cost and the inability to ship full assembled 2.5 mtr. wide cats.

Again it must be realized that the proposal is two-fold and we will have a seperate vote an each part.


>>It may be cheaper in the UK & US than in AUS & SA relative to aluminium.

Some of us have serious looking into that (myself included) and it is expensive were ever you try to order them.


>>On the subject of regulating the beams, I`ve had a look at the proposed Tornado class rule changes, they have a MAX. thickness limit on the aluminium walls of their beams, to prevent competitors from making HEAVIER beams, so that they could then build lighter hulls & have the same platform weight, with the weight taken out of the hulls & positioned where you would want it, more centralised in the platform. I don`t know if anyone in the F16 class would go to such lengths to try & gain a small advantage, but perhaps we should look at regulating this as well.


(Chairman) if you are serious about this please form an official and fully worked out proposal to the F16 class.

(Private sailor) I really don't see how much more weight can be taken from the hulls now that these are already very lightweight considering the loads the F16 has to withstand. My estimate that the tornado rule is far more driven by one=design considerations than a real danger that such an action would really introduce a noticable performance difference between boats. Please note that 5 kg difference in crew weight will add a bigger inequality in rotational enertia your described action can ever cause. Please do the numbers on that.

(Private sailor and proxy Greg goodall) In addition ; no one can easily tell if a boat has seen such a modification or not. This is not the case with carbon beams; these are highly visible and therefor easily regarded as the cause of any difference in performance even though the cause may be completely different.


>>While on the subject of Carbon being expensive, how can the class allow full carbon hulls if one of the goals of the class is keeping it affordable ?


Carbon itself is not that expensive with compared to glass, the laminating of a hull (labour costs)and other costs related to hull production; Therefor the savings here are pretty minor.

Of course the cost of an alu beam is strikingly low because of the mass production of these standardized items for other uses. carbon beams are by definition custom items as they need local reinforcements in stress points like the maststep and because the demand for standardized carbon tubes is not even close to those of aluminium.

Compare it to CD-rom making. Making 10 CD-rom reader units would cost 50.000 dollars per reader. However producing 1.000.000 of them to a world market allows mass production technics to drop the price to 50 Dollars. (real numbers as this is partly my field). The same situation is applicable to mass production of alu tubing.

I repeat my earlier statement in one other post that no builder (including AHCP) considers building these beams themselfs in house. All have to perchase this from a specialized company. And we all the quality laminate work of AHPC. If they are not considering it them it is serious business.


>>Or is it just that manufacturing beams in carbon costs so much, while using it for hull manufacture is not ?

That is part of the reason.


>>This raises the same issue, you can build superlight hulls in full carbon & add lead where you want it, keeping most of the weight centralised, a plywood boat the same weight would be at a distinct disadvantage in this regard. Is this within the spirit of the F16 class & it`s intentions ?



I refer to my earlier example of a 5kg difference in crew weight. I would like to see anybody proof that such superlight hulls can be build and how much the real gain is before assuming that a ply boat is at a distinct disadvantage. As it stands right now, Plywood hulls are still regarded superior by several to glass hulls. Biggest problem with ply is however that hull designers are limited in shaping a hull. That is a much more significant limitation than any rotational enertia contribution. Please remember that foam itself as needed in glass hulls is not particulary light and doesn't have high compression (dent) resistance. Ply however has a very optimal strength to dent compression to weight ratio.

I serious beleive the described danger to be in the realm of fictional at this time.

I'm however open to fully worked out proposals.


I would like to add that Greg's proposals are worked out and checked out for truthfulness and realisme. (That is what the class does when receiving a proposal; no proposal is automatically garanteed a vote. Several experts have given their opinions on the proposals before such a proposal was publized)



>>>We need to consider these points carefully, or our class will become F16HT very quickly, and the entry cost will escalate. We need to be careful here : one of the main attractions of the class is that you can have similar performance to A-class & F18 at a much lower cost. If the costs go up, the attractiveness of the class diminishes.


I personally full agree with this statement. We have the change now to alter the direction without causing harm to anyone.

Wouter