#96793 - 01/26/07 03:04 PM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Wouter]
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addict
Registered: 08/20/02
Posts: 545
Loc: Brighton, UK
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Quote:
In arguments like these I advice somebody like yourself to develop you mathematical models further, they still allow conclusions that are in direct conflict with eachother and as such lead to errornous conclusions. Your models are not yet well defined.
I have a model that takes into accounts all influences like changes in angle of attacts etc and the one clear conclusion was that with each reduction in sailarea the boat because disproportionally slower. Even at 9.00 sq. mtr. (my 3.90 mtr design) I could achieve 10-11 knots at maximum. Which is fast but a 5.00 sq. mtr. sail area at a significant lower aspect ratio will be well below 10 knots (around 6 knots or so).
My experience of using windsurfing rigs on a multihull does not match your mathematical models, from your comments it appears you have developed your own VPP. It does not seem to be giving realistic results. Perhaps it does not scale well.
Look at the international Moth Length=3.4 beam=2.2 SA=8m2 similar total displacement to an F12, with a windsuring sail it goes significantly faster than your models would predict.
Gareth
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#96796 - 01/26/07 07:01 PM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Wouter]
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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As a side note.
Even if I write in a agressive manner, nothing is personal !
That is just the way I write and it is hardwired in my system, tried to be more diplomatic in the past but that just wasn't me.
Please take it from me that I always keep my eye on the ball. I do respect different opinions.
Wouter
Edited by Wouter (01/26/07 07:03 PM)
_________________________
Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
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#96797 - 01/27/07 02:21 AM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Mary]
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veteran
Registered: 06/08/04
Posts: 1477
Loc: Thailand
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Sorry I still dont quite understand what is the big deal with it not being exactly 12 foot?  Quote:
Quote:
Wouter has pretty much said here are the choices based on the underlying mathematics are:
1. a 12 foot boat with a less then desirable sail area, making it a low performance boat, like the ones already available to purchase.
2. a 12 foot boat with the propensity to pitch pole
3. a 1210 that with neither of the two problems.
But those choices are slanted to bring you to the conclusion desired by their author, and they are based upon the premise that what is wanted for the Formula 12 class is a fast, high-performance boat. And also to fit the boat that he had already started designing.
And all the math proves is that Wouter believes the kind of boat he envisions building cannot be done as a 12-footer.
So, in other words, if he can't build his dream boat to fit within a Formula 12 class, he is going to stretch the class to fit a 12'10" boat.
Also, 10 additional inches makes a MUCH greater difference in a small boat like that than it would if you are talking about, say, a Solaris 42 if it is actually 42'10".
If Wouter builds a boat almost 13 feet long and calls it an F12 and expects it to be representative of a Formula 12 class, a Formula 12 class will never come into existence.
If he proceeds with that particular design, he should call it something other than F12 and then make that particular boat a one-design.
Meanwhile, it would be nice if somebody would come up with some box rules for a Formula 12 class and limit it to 12 feet. 
_________________________
"House prices have risen by nearly 25 percent over the past two years. Although speculative activity has increased in some areas, at a national level these price increases largely reflect strong economic fundamentals." Ben Bernanke 2005
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#96800 - 01/27/07 09:11 AM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Wouter]
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Carpal Tunnel
Registered: 11/12/02
Posts: 5558
Loc: Key Largo, FL & Put-in-Bay, OH...
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Wouter,
Forgive me if I have missed things in the plethora of posts, but is your design going to include trapeze and spinnaker? I'm thinking NOT, based on the unstayed mast-sail rig being proposed.
I have been trying to think where your design fits into the big picture of youth sailing. When we are talking about youth sailors from 13-18 years of age, most of those with any sailing experience are able to handle the Hobie 16 and the SL 16, which are the boats being used for ISAF World Championships (both using spinnakers).
Seems like your boat, being smaller, lighter, home-buildable and therefore less expensive than the bigger cats the kids are using for the major sailing events, would be a great trainer boat for those who cannot afford to buy an SL 16.
Maybe what we ALL need is just a good, small, light, easy-to-build PLATFORM that can be used with a bunch of different types/combinations of sails and standing rigging, depending upon how any given sailor wants to USE the platform -- ages, weights, goals of entry level or racing level, etc.
The options and combinations for rigs are endless -- sprit sail, lateen rig, Laser-type rig, windsurfer/landsailor rig, traditional stayed unirig, sloop rig, spinnaker, reacher, boom or boomless, fully battened or no battens, traveler systems of all different kinds or boom vang if there is a boom...
It would be so interesting to have a platform that everybody can build and that everybody can decide what they want to do as far as what they put ABOVE that platform in terms of sails.
I know you don't like all the "round and round" discussions, but I think of it is sort of like panning for gold. If you pan long enough, you might get a nugget of wisdom, a flash of gold, out of the stream.
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#96801 - 01/27/07 10:34 AM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Mary]
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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Quote:
Wouter,
... but is your design going to include trapeze and spinnaker? I'm thinking NOT, based on the unstayed mast-sail rig being proposed.
I can have a trapeze, nothing technical is preventing it, but it won't. Reasons, it is neither simple not inexpensive. Additionally the sailarea will be relatively small, so it won't be used very often. In short the return against the investment is not interesting enough.
An additional reason is that singlehanded trapezing is considered a skill. My idea for the F12 was to have a boat that was regarded unintimidating and easy to sail/setup so that it would be a good entry into cat sailing and apparent wind sailing for absolutely novices (both kids, youths, teenagers and adults)
Quote:
I have been trying to think where your design fits into the big picture of youth sailing. When we are talking about youth sailors from 13-18 years of age, most of those with any sailing experience are able to handle the Hobie 16 and the SL 16, which are the boats being used for ISAF World Championships (both using spinnakers).
You yourself said many times that racing is not everything. Now I've been earlier involved in a class of cats that certainly qualify are race oriented. They are lean and fast but can be mean at times. This time I wanted to offset that by having a well performing boat that was easy and very well behaved, plus very economical to purchase and operate. For the group of sailors who are not interested in racing , but far more in an enjoyable hobby.
Of course the boat doesn't have to be low performant or against racing, it only needs to avoid making compromises if racing would demand those, against simplicity and easy of sailing/rigging. The trapeze is such a thing I believe.
Quote:
Seems like your boat, being smaller, lighter, home-buildable and therefore less expensive than the bigger cats the kids are using for the major sailing events, would be a great trainer boat for those who cannot afford to buy an SL 16.
I think it would be a great trainer for everybody, including owners of real racers like myself. Time-on-the-water is the must important ingredient for succes. I would like to have a boat myself that I can rig and derig under 5 minutes, so I can go sailing in those little hours were rigging up to big one is too must effort or too time consuming.
For the same reason my design won't have a spinnaker, it can but it won't as a class.
Additionally, because of its simplicity it will be very easy to learn "the ropes" on. What I'm trying to so is design a go-cart for sailing. Yes a go-cart is not a nascar or F1 race car but quite a few drivers started out in these things when they were young and moved up later on. Go-carts are relatively inexpensive (compared to the larger bolides) and easy to operate as they have no clutch and no gear box. And a go-cart race course can be setup on a very small piece of land. Overhere we have race tracks inside inner city former warehouses and storage buildings. Hugely popular.
Quote:
Maybe what we ALL need is just a good, small, light, easy-to-build PLATFORM that can be used with a bunch of different types/combinations of sails and standing rigging, depending upon how any given sailor wants to USE the platform -- ages, weights, goals of entry level or racing level, etc.
Not trying to overpromote my design but that is actually what my design allows. At this time the exact same platform with mast foot design will take :
-1- The class 5 landyacht rig
-2- The laser 1 rig
-3- The windsurfer rig
-4- The gaff rig
-5- The lugger rig (= very interesting for extreme simplicity and low cost)
and it will even take the sprit and lateen sail setups but both or these are not as efficient as the ones named earlier.
All these rigs can be used because the platform allows the use of an unstayed mast.
A lateen sail will be rather difficlt to fit to this F12.
Quote:
It would be so interesting to have a platform that everybody can build and that everybody can decide what they want to do as far as what they put ABOVE that platform in terms of sails.
Well , my idea was to base the class rules upon the most performant setup that can be had. Then all the simpler and less performant versions can be part of the class as they will never have any speed advantage not matter how well they are build.
Quote:
I know you don't like all the "round and round" discussions, but I think of it is sort of like panning for gold.
I don't think this particular posting was a "round and round" type of posting.
Wouter
_________________________
Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
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#96802 - 01/27/07 03:18 PM
Re: Please give your opinion on ... SMOD/ OD / For
[Re: Mary]
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Carpal Tunnel
Registered: 03/19/02
Posts: 3067
Loc: Key Largo, FL and Put-in-Bay, ...
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Been busy but wanted to reply to the Wave Pooh-Pooh Poster. Wow, whoever quoted the prices on that makes it sound like it should be racing with the A-Class Boys -- don't know how you could get the price up that high, but you did. First of all, there are already a zillion Waves around and used Waves can be acquired at very reasonable prices. To add the Hooter does require spending some money to nearly double the sail power. Granted! But, it would still be as inexpensive as any other proposed boat here in the long run. Add the fact that for kids this boat would be indestructible. They could hit sea walls and pilings and still keep on ticking like the Energizer Bunny. And only 2 inches longer than the proposed F12 box rule proposed herein. Rick
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