| f14 limits!! #30494 02/25/04 09:11 PM 02/25/04 09:11 PM |
Joined: Feb 2004 Posts: 1,012 South Australia Darryl_Barrett OP
old hand
|
OP
old hand
Joined: Feb 2004
Posts: 1,012 South Australia | There are a lot of people who seem to express their "dreams" when it comes to "unrestricted" (apart from hull length, mast height etc) for a formula 14! When you really get down to the practical limitations for a design for a 14' cat, you soon work out that to put "a 150 odd sq ft jib, with a 150 odd, sq ft main, on a set of production hulls that like the Hobie 14, already carry more sail area as standard, than the hulls are able to accomadate efficiently ( the key word here is "efficiently"), that to carry more sail just makes the cat harder to sail, and in most cases, slower around a triangular course. To be able to "carry" sail, the first consideration is the bouancy, and positioning of that bouancy, of the hulls. They have to be as least resistant as possible to "drag" created by any sudden forces of forward motion that exert downward, as well as forward acceleration to the cat. If they aren't, then the bows "trip" (commonly known as pitch polling). They have to support one or two crew, not only inboard, but out on trapeze, and still resist "tripping" Remember you are sailing a catamaran, not a partially submerged submarine. The wider the hulls are placed apart on a cat (passed their ideal width for their length) and provided that the fore and aft position of the mast step remains the same, more and more insability and "tripping pressure is applied to the bows of the cat, so instead of creating a more stable platform, the reverse is generally the case. Wider placed hulls mean that you can resist the side way, lifting forces of the sails (and the lift of the hulls) more, but the fore and aft instability more than negates any advantage that you may get from that, and besides, we have comprehensive sail shape controls to control the "hull lifting" forces and convert them into forward motion ( that's what sailing is all about, converting wind generated "lift" into forward motion - regardless of which way the apparent wind is coming from). There is a global formula for assessing the efficiency, stability, and potentual performance of any sailing craft, and if any of the dimensions of that craft fall outside that formula, then it loses efficiency. As a very rough example, imagine a transperent sphere (ball for the less educated ha ha), place the cat that you want to check the potentual of, inside that glode. What you want to be looking for is that all the extremities of that cat will be just in contact with the inside of that globe, if the head of the mast is, but the hulls are not, then there will be instability greater than the potentual obtainable, etc, etc. What I am saying is that, when it comes to sailing fast, the old addage, "you can't beat cubic inches" commonly referring to cars, just doesn't apply to boats, just adding more sail often reduces the performance of a cat, its not what is added but how it is added, and it has to be added within the potentual performance perameters of that cat (if you want to "suck it and see", just step the rig of a Hobie 16 onto a Hobie 14 and you will soon see whether or not it works). Yours Darryl J Barrett | | | Re: f14 limits!!
[Re: Darryl_Barrett]
#30495 02/25/04 09:55 PM 02/25/04 09:55 PM |
Joined: Sep 2003 Posts: 84 ms/fl fuzzy
journeyman
|
journeyman
Joined: Sep 2003
Posts: 84 ms/fl | yo dude, I do not quite understand your post.........Why dont we just see what shows up......could be very interesting....tr
A-class #19
| | | Re: f14 limits!!
[Re: Seeker]
#30498 02/25/04 11:26 PM 02/25/04 11:26 PM |
Joined: Feb 2004 Posts: 1,012 South Australia Darryl_Barrett OP
old hand
|
OP
old hand
Joined: Feb 2004
Posts: 1,012 South Australia | I have no desire to "limit" any ones experimentation with different configurations for, hulls, mast type and height, sail area, etc, etc, I say "bring them all on, and lets see just what holds up and is competative", What I wanted to point out was that to successfully "alter" an existing cat, or produce a new design, and have an improvement in performance, then you just can't alter one aspect of the cat without dramatical changing other areas of the cats performance/handling. It has to be seen as a "complete package" where the mast and sails match the hull and platform, as well as the rudders and/or centre boards, etc, etc. If you just put up larger sails, and if you have centre boards, then it is likeley that you are dramatically altering the centre of effort of the sails in relation to the centre of lateral resistance of the hulls, and you will completely change the steering characteristics of the cat ( some times to the point of uncontrolable weather helm or lee helm, often even more so on a centre board less cat). I would love to see ALL the extremes of designs actively compete in the 14' cat area, so that perhaps some one MAY just MAY hit apon a successful new revolutionary concept that has been sitting under our noses, so obvious that no one has even noticed it. Darryl J Barrett | | |
|
0 registered members (),
378
guests, and 87
spiders. | Key: Admin,
Global Mod,
Mod | | Forums26 Topics22,404 Posts267,055 Members8,150 | Most Online2,167 Dec 19th, 2022 | | |