Mast controls (Diamond tension, Spreader rake, Spreader length, mast rake,shroud tension) were carefully tested through a very large range of variables. We can confirm that with the carbon mast there are less difficulties to find the basic set up for the proper matching with the sail.
Call me a lousy engineer but how does anyone explain this conclusion exactly ?
Are turnbuckles easier to turn on a carbon mast ? Or are spreaders more easily adjusted on a carbon mast ? May the stainless steel shrouds notice the material chance of the nearby mast and behave differently ?
Or could it be that carbon masts have smaller ranges in which they can be realistically adjusted ?
That latter point is not exactly what we're looking for to increase equality in a large range in crewweights is it ?
But it certainly would explain the next statement :
We clearly confirmed what was already known: on carbon mast the sail has to support much higher loads.
Translated : higher sheet and downhaul loads are required to get a carbon mast sail into the right shape for different conditions then it was designed for. Those Tornado guys better be prepared to go to 1:10 sheet systems. Now everything will be loaded up more. Hulls, main beam, rearbeam, forestay. This will do wonders for the perceived stiffness of the platform.
Funny, may turn out that aluminium had its advantages as well. Looks like a large range of adjustment combined with lower loads is one of these. It just occured to me that alu indeed has a high flex to load ratio without closing in on any risk zones. I don't know the right word for it in English. But is like "wiry" or "leathery". You can stretch and pull it and it will flex enough to give way but will hold its consistancy; its basic structure. Wood has similar characteristics. Both can take inpact loads rather well before losing integraty. They do it by adsorbing enough of the shock by flexing. And they are both quite resiliant to developping cracks and ruptures. And when they do fail they do by a path of degradation instead of failing with a bang.
Makes me remind of the mono-film mainsail stage that has passed now. When cut exactly right they were fast but when even the smalles mistake crept in or when the conditions/crew differed too much then the dacron sails of old were passing you. And when they were hit the wrong way with any pointy object they would explode in one big rupture.
But I must say, this article said alot more than it probably wanted to and it was valuable.
(note that it appears to support what I know from other, independent, sources)
Wouter
