Should we impose a sail area/length2 limit?

[FAST FRED]

"Carbon fiber has issues with stress, because it wont show fatigue at all. Instead, it will hold together until it explodes under pressure."

Even when "professionally " built ,the problem is there is no way to test (short of distruction) to find flaws or overload deteoration.

Ask AIRBUS , about the rudders falling off their Carbon Fibre tail section.

FAST FRED

[mackid068]

Well, perhaps metals provide an alternative, for some of the boat components, titanium, say, for masts and spars.

[daveculp]

Originally Posted by Lorsail

Thanks Soren; I didn't realize that. Too bad there isn't just one accepted ratio for this purpose.

The ratio you guys are discussing; sq rt sail area divided by cube rt displacement has a name. It's called the Bruce number, after Edmund Bruce who first proposed it in the 1960's. It is in wide usage (Google returns 1200 pages for "bruce number"), can be found for most hot boats.

It has limitations, for instance when comparing widely disparate boats (windsurfers versus open 60 tris, for instance), but it is a very useful simple measurement of a boat's "power/weight" ratio.

Dave Culp

[daveculp]

Originally Posted by xarax

When the thread was posted, it was meant to provoke a discussion on the usefulness or not of just that: a modern box rule, as simple as possible, taking into account sail area and length2. With recent technological developments, an upper limit of SA//LWL2 of 1 for upwind would be quite reasonable. SA 225 sqft for a 15 ft LWL boat.Any suggestions?

This is an interesting thread with predictable sides--uber-capitalistic Americans proposing no rules, including wealth-restricted ones; uber-conservative (dare I say soci*list?) Greeks and other Europeans proposing governmental intervention in the name of "fairness and safety for all." Aussies proposing whatever is hot in OZ at the moment--it's all business as usual, isn't it? ;-)

Couple of observations: Chris is right-on regarding OD classes and affordability of sailing--but then what has ultimate speed and horsepower got to do with affordability?

Xarax is right that heavily controlled sailing is "fair" for all, but again, that wasn't the proposition, was it? Define your terms please, Xarax; is "good" design one which favors poor sailors? rich sailors? Talented sailors? Innovative sailors? Is a popular class somehow "better" than an unpopular one? Exactly why? For whom? (I think it was Dick Newick who said, "There's fast, comfortable and cheap. I can give you any two")

Regarding box rules; Very cool idea, but easily subverted--do appendages (sprits, booms; removable topmasts) count? Can the sail area belly outside the box? Can a kite sail completely outside the box? I'm not asking for answers, but rather for thought; one can use a "fair" box rule to, for instance, allow existing long-sprited boats to be grandfathered in and dominate the "class", or to outlaw kites out of hand, any number of things--for purely political reasons, not design or sailing ones.

Regarding cost and materials; we are learning--and teaching--that some types of sails (yeah, kites) can be built far less expensively than "conventional" rigs and sails--should this automatically cause them to be encouraged? More to the point, kites' non-heeling and centralized load-path attributes mean that very fast boats can be built of quite humble materials--like plywood and simple e-glass--which can be stiff enough and strong enough to make very, very fast boats. Remember, kite boats don't need any ballast at all, nor wide beam, multiple hulls, connectives, etc.

On a cost basis, then, everyone should be designing and racing kite boats, no? ;-)

Dave Culp
http://www.kiteship.com

[CT 249]

Interesting notes, but not sure about "This is an interesting thread with predictable sides--uber-capitalistic Americans proposing no rules, including wealth-restricted ones; uber-conservative (dare I say soci*list?) Greeks and other Europeans proposing governmental intervention in the name of "fairness and safety for all." Aussies proposing whatever is hot in OZ at the moment--it's all business as usual, isn't it? ;-)"

Aren't US small boat sailors on average very conservative and renowned for their devotion to ODs? Small but significant classes of As, Cs, ICs, F18HTs and I14s are more than counterbalanced by fleets of Lightnings, Flying Scots etc aren't they?

The "conservative" Euros sail conservative boats sometimes, but they also sail Garda boats, all (or almost all) of the ORMA 60s, G Class, Minis, Micros, Open 60s, and have many more skiff types than the US.

The Aussie proposals about "what's currently hot" include a class over 100 years old; that's been "current" for a long time!

FWIW the US "no rule" element has not been very succesful in terms of creating innovative AND popular OR long-lastiing development classes has it?

[daveculp]

Are we gonna do the old "who's got the best designers" thing again? It was a joke, Chris, a joke. Thank god there are no stereotypes--like aussies who'll argue about which side a piece of bread will fall on... (another joke, Chris, another joke.)

Dave

OD's OD's OD's. Is it actually possible to have a conversation about sailing technology without referring to them? Apparently not.

[usa2]

little, if any sailing technology advances come with OD's because they discourage development. Development classes such as the moth, ACC, Open 60 and several others (including multihull) is where the big advances in sailing technology come from.

[gggGuest]

Originally Posted by daveculp

Thank god there are no stereotypes--like aussies who'll argue about which side a piece of bread will fall on...

Na, Aussies wouldn't *argue* about that. Now if you're talking about a bet of course... well 5 will get you four that it will land butter side down...