Hey don't drag me down with you. All I said is was that the Woutinator needed a little love, I never said he needed to get hit by a train.

I'm a peace loving man.

Ding

Well, I guess it must just be your 'sense of humour' then. I do tend to laugh (or smile) at things that are actually witty or funny, in fact I'm renowned for it. So perhaps I just need to tune in to your particular brand of 'humour'? <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

Sorry Ding. I can't help but drag you down in whatever I do.

Ok Wouter, you're right.

I've done some back of the envolope type calculations. I came up with a maximum of 3% weight reduction through pre-bend. The result will vary according to the specific geometry. You can take some weight out of the main beam, but much of that reduction is cancelled out by the extra weight you have to put into the dolphin striker.

Of course, if you downsize to take advantage of the added strength, you will lose some stiffness.

Interestingly, if you could measure in with highly pre-bent beams and then flatten them out on the water, you could effectively get some hull cant.

Rhino,

Saving weight will indeed always be a trade-off with losing stiffness. But it can be won back at other places as well.

My mainbeam is about 3.8 kg as a bare tube and yes I would welcome a little more stiffness. Because my mainbeam is so light I need more then 15 mm of prebend to keep it under a nice load situation while sailing. But I admit, as I wrote earlier, that the F18 beams are much heavier and stiffer, I don't really expect them to go past 15 mm of prebend. So in the F18 case it is not a really serious issue. I think the optimimal point is somewhere halveway.

By sailing my own boat I found that platform stiffness is not a very large component in the way of performance. And lots of stiffness is often lost in the beamlanding design and other places.

As an engineer I look at the rule sets from a designers point of view. Freedom allowed under them is in my opinion more often used to arrive at simpler or more elegant solutions then for performance gains. Limiting the designers freedom in this can eventually became a drawback for a class. But I admit that this view may well be subject to disagreement.

Anyway, I'm out of time on this topic. I have to complete another design assigment. (Why do I always slack on these till it is almost too late to finish them in time ?)

Wouter