| Re: Taipan Mainsail
[Re: Wouter]
#84934 09/18/06 05:03 PM 09/18/06 05:03 PM |
Joined: Jul 2006 Posts: 461 Victoria, Oztralia mattaipan OP
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Posts: 461 Victoria, Oztralia | Hi All
No worries then. I am a little confused though, the sail would fit into F16 specs, so we will, if approved, have adopted a F16 mainsail? Or is it the fact that it still has measurement restrictions?
Matt
Matt Harper
Homebuilt Taipan 4.9
AUS 329 'GOT WOOD' SEEDY PIRATES RACING TEAM
| | | Re: Taipan Mainsail
[Re: mattaipan]
#84935 09/18/06 05:38 PM 09/18/06 05:38 PM |
Joined: Jun 2001 Posts: 9,582 North-West Europe Wouter
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Matt,
I think this is hard to say.
We may find that sails compliant to the proposed rules are F16 compliant but from the rules themselfs this may not be garanteed.
F16 rules on the Mainsail are :
max area including mast = 15.0 sq. mtr max luff length = 8.10 mtr. (when downhauled)
So F16 class rules will not easily disallow a given mainsail design.
However, it may be possible that the proposed rules still allow a flap at the bottom of the Taipan sail which puts its total area passed 15.0 sq. mtr. Rolf made a rought estimate of the area but did he envision all the possible ways to maximize the mainsail area ? Maybe there are other loop holes that do conflict with either F16 rule. The limits on width and leech/foot lengths do not in themselfs limit the total area of the sail to max 15.0 mtr.
I think the proposed class rules do limit the max luff length to the same level as the F16 rules have set it. So no problem there.
Additionally, the issue raised by Paul is that the much more detailed Taipan rules as proposed may in fact conflict with existing (or future) F16 mainsail designs of some sailmakers. In effect these sailmakes will always have to check their designs against two different sets of rules when the performance determining features are identical. I have understood this to refer to a situation where the limits are needlessly confusing for sailmakers.
The way I understand it is that only two situations can result from the proposed rules :
-1- The F16 sails are not necessarily Taipan compliant -2- The Taipan sails are not necessarily F16 compliant
Either way the sailmakers are pretty much required to develop two different mainsail designs for effectively the same mast section and comparable boats.
I share the opinion that this is not really handy to both sailmakers and sailors. It can only lead to higher prices (as more work is involved) for zero differences in performance. Also it will hamper the second hand market in these items.
Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
| | | Re: Taipan Mainsail
[Re: mattaipan]
#84938 09/18/06 07:50 PM 09/18/06 07:50 PM |
Joined: Jan 2004 Posts: 196 Arkansas, USA CaptainKirt
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Posts: 196 Arkansas, USA | Okay- All this talk of new Taipan 4.9 mainsails for the AUSSIE class is fine BUT- What is that going to do for the Non-Aussie Taipan 4.9's??? <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> Since all Taipan 4.9's to date (to my knowledge) have followed a single set of OD rules if the Aussie Taipan Class votes to change "their" rules does it effectively (or completely and totally) change "the" OD rules for every Taipan on the planet?? If so, then I think every Taipan 4.9 owner on the planet should be entitled to vote, including all the ones in the US, EU, Asia, etc.!! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" /> And if the "Aussie" rules can be changed by just bringing it up and voting on with a 2/3rds majority which won't change "the" rules or "our" rules then I propose that all the Non-Aussie Taipan 4.9 owners hold our own vote to change both the Mainsail (and jib?) to be F16 compliant. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> Would sure allow me to save money and sail as either 4.9 OD or F16 much easier/cheaper. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" /> Kirt
Kirt Simmons Taipan, Flyer
| | | Re: Taipan Mainsail
[Re: CaptainKirt]
#84939 09/18/06 09:20 PM 09/18/06 09:20 PM |
Joined: Nov 2005 Posts: 337 Victoria, Australia C2 Mike
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Posts: 337 Victoria, Australia | Okay- All this talk of new Taipan 4.9 mainsails for the AUSSIE class is fine BUT- What is that going to do for the Non-Aussie Taipan 4.9's??? <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> Since all Taipan 4.9's to date (to my knowledge) have followed a single set of OD rules if the Aussie Taipan Class votes to change "their" rules does it effectively (or completely and totally) change "the" OD rules for every Taipan on the planet?? If so, then I think every Taipan 4.9 owner on the planet should be entitled to vote, including all the ones in the US, EU, Asia, etc.!! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" /> And if the "Aussie" rules can be changed by just bringing it up and voting on with a 2/3rds majority which won't change "the" rules or "our" rules then I propose that all the Non-Aussie Taipan 4.9 owners hold our own vote to change both the Mainsail (and jib?) to be F16 compliant. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> Would sure allow me to save money and sail as either 4.9 OD or F16 much easier/cheaper. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" /> Kirt I think you will find that it only relates to the Australian National Taipan Class. That means that only members in good standing with that association should have the right to vote on this change. If other associations around the world choose to have their rules based on the Australian model then that is up to them. I see no reason why international sailors should vote on Australian Class rules. If they don't like them, then they always have the option of adopting any rules they like in their country. They always have the opportunity to join the Australian Association if they want their vote cast. Tiger Mike | | | Re: Taipan Mainsail
[Re: macca]
#84942 09/20/06 06:13 AM 09/20/06 06:13 AM | Anonymous
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Unregistered | Hi all,
I am sure some may have thought of this but I will post it any way.
The major problem with this proposed change to Mainsail as far as F16 compliance is concerned, is that they are not changing the Jib to the smaller F16 jib at the same time, which means that the overall sail area will be greater than that currently allowed by F16. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />
This I would imagine makes Grandfathering more difficult. It would certainly make Taipans competing in F16 events in OZ difficult, but I would imagine this problem would be the furthest thing from their minds.
This is unlikely however as most of the talk I have heard has been negative, except the big cat rig guys that used the sail and the few Taipans that sail as F16 most of the time. but they are in the minority. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />
No doubt I may hear some more at Forster next week.
Regards Gary. <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> | | | Re: Taipan Mainsail
[Re: Stewart]
#84944 09/21/06 10:15 PM 09/21/06 10:15 PM |
Joined: Jan 2004 Posts: 196 Arkansas, USA CaptainKirt
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Posts: 196 Arkansas, USA | Stewart- I believe it is up to the Aus F16 representative to make this determination for Aus. For the US it would be my contention that a "stock" 4.9 showing up to race against other F16's with such a sail would be allowed to as a cat rig with main only but not as a sloop with the large (ie original) jib. If the boat had a F16 (ie smaller self-tacking) jib then it would be "legal" IMO. It would be interesting to see if the larger, tramp mounted block jib is any faster than a self-tacker equipped jib F16 with both running comparable spinnakers and on a windward-leeward fairly short course I'm not at all sure it would be. In a distance or long race and under certain conditions perhaps and without spinnakers it might prove to be quicker.
Kirt
Kirt Simmons Taipan, Flyer
| | | Re: Taipan Mainsail
[Re: phill]
#84946 09/22/06 08:36 PM 09/22/06 08:36 PM |
Joined: Nov 2005 Posts: 337 Victoria, Australia C2 Mike
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Posts: 337 Victoria, Australia | Kirt, What you say makes a lot of sense however the advantage of the bigger jib would probably only be evident on triangle courses and distance racing. Regards, Phill IMHO if there is a rule in the book, it should be followed. Especially if it is such a basic thing like motor size! If the rule is wrong or redundant then change it but while it is there it should be followed. Tiger Mike | | | Re: Taipan Mainsail
[Re: warbird]
#84948 09/24/06 01:56 AM 09/24/06 01:56 AM |
Joined: May 2003 Posts: 4,451 West coast of Norway Rolf_Nilsen
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Posts: 4,451 West coast of Norway | The alteration in sailplan for the Tornado in 2000 was a larger square top mainsail, spi and a jib with longer luff. I dont think the 'new' Tornado jib is much larger than the old one. One interesting thing they found during the test event at Quiberon was that the old-rig Tornado was faster upwind than the "new" rig. Even with the added power of larger sailarea and double trapeze, the old rig was very effecient, well known and did not have the extra weight/drag the spi-gear added. So if your Tornado friends say that their upwind performance has improved hugely with the new rig, something must either have been wrong with their old setup, or the new-rig saildesigns have improved since the test event (which is very possible). A longer luff (and aspect ratio) is more effecient then a shorter luff, which means better speed in most conditions. When overpowered and especially on a reach, a shorter luff but more area (lower aspect ratio) can be faster. If I could choose, I would choose high-aspect ratio any day, as you can then install a selftacker. A selftacking jib makes all the difference upwind singlehanded (not legal when racing F-16) and downwind under spi in any configuration. For more information about the ISAF evaluation event, which is good reading: http://old.cruisingworld.com/2000/03/isaf1.html | | | Re: Taipan Mainsail
[Re: Rolf_Nilsen]
#84949 09/24/06 02:22 AM 09/24/06 02:22 AM |
Joined: Jun 2001 Posts: 9,582 North-West Europe Wouter
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Posts: 9,582 North-West Europe | The tornado jib before and after the 2000 change is the same in overall area. Source www.texelrating.orgTornado classis jib area = 5.20 sq. mtr. (with luff length = 5.62 mtr) Tornado (upgraded) jib area = 5.22 sq. mtr. (with luff length = 5.87 mtr) The luff lengths don't seem to differ that must either. So I agree with Rolf here; the guys you spoke to must have misunderstood the jib change, Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
| | | Re: Taipan Mainsail
[Re: warbird]
#84953 09/24/06 06:34 AM 09/24/06 06:34 AM |
Joined: May 2003 Posts: 4,451 West coast of Norway Rolf_Nilsen
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Posts: 4,451 West coast of Norway | I expect the AC boats are as they are becouse of their rules framework and speed range. The slot effect is.. pretty much a myth. The jib is so very effective becouse it works in the updraft the main creates. It is not a good thing to close the slot, but that is not the key to the sloop rigs efficency. The airstream is 'bent' before it hits your sails, whatever kind of rig you have (I'll not go into the physics behind why it is bending before it makes contact with the sales, but think about your bow-waves and how they look at low speed). If you remove the jib and sail uni, the airstream still bends before it hits the mast, creating an pressure area just in front of the mast and over the leeward side of the sail. When you put a small sail in front and to leeward of your mainsail, it works in an airstream already influenced by the mainsail, taking advantage of this. That is why the jib is so effective pr. surface area compared to the main, and why a good jib is so important. For a much better explanation than mine, here is what the late Arvel Gentry had to say about the "slot effect": http://www.arvelgentry.com/magaz/Another_Look_at_Slot_Effect.pdf | | |
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