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How long should a spin pole be? #13678
12/03/02 01:47 PM
12/03/02 01:47 PM
Joined: Apr 2002
Posts: 591
Bradenton, FL
Sycho15 Offline OP
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Sycho15  Offline OP
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After the fascinating discussion on spinnaker lift versus 'leveraged bow dive', I'm still left wondering...

How far does the spinnaker pole need to be past the bridle to give at least enough lift to cancel out the bow-dive. Preferably, I'd like a little more lift than dive so crew position could be more flexible.

Since the bridle is where the pole will be lifting from, that is where the measurements should be taken. Also, since we are taking into account a vast number of different boats, with different distances from their forward beams to the bridles, it is the only way to communicate this issue in a fashion that covers them all.


G-Cat 5.7M #583 (sail # currently 100) in Bradenton, FL Hobie 14T
-- Have You Seen This? --
Re: How long should a spin pole be? [Re: Sycho15] #13679
12/03/02 03:31 PM
12/03/02 03:31 PM
Joined: Jul 2001
Posts: 364
Andrew Offline
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Andrew  Offline
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Posts: 364
Technically, the measurement should be taken from a point directly below the hound on the mast, as the amount that the chute "lays back" determines the angle of lift; that is, what percentage of the lift generated is vertical versus horizontal. With a pole length of zero, all lift is horizontal and you are talking about your main sail. The Aussie 18 skiffs use very long poles, and frequently triple-trap off the rack which extends 2 feet or more aft of the transom. http://www.18footer.org/Galleries/D...ternational_Championship_2002&Page=2
The boats would reverse-pitchpole if they tried that upwind. This is why we run footstraps on kite cats, very often.
The short answer is "very long", and the other short answer is "it depends". It depends on the size of the sail, how much air there is, how much lee helm you can stand, and how much pole you can stand. Like I mentioned in an earlier post, some classes limit the length of the pole.
All that said, I have sailed my P-19 with small chute with 11' and 12' poles and could not tell a difference; I am in the process of rigging a 15' pole now, with a larger sail, and I'll fill y'all in. I figure with modest rake, the tack will be about 16' ahead of the head, and since the luff is about 31', this works out to about 40 degrees of angle on the luff. I think.

pix upcoming, and I'll take it sailing in the spring
sail fast y'all


Andrew Tatton Nacra 20 "Wiggle Stick" #266 Nacra 18 Square #12
Re: How long should a spin pole be? [Re: Andrew] #13680
12/04/02 08:26 AM
12/04/02 08:26 AM
Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
Todd_Sails Offline
Carpal Tunnel
Todd_Sails  Offline
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42.904444 N; 88.008586 W
Andrew, Thanks for the link.

Wow, Great pics! The size of those chutes is scary!


F-18 Infusion
#626- SOLD it!

'Long Live the Legend of Chris Kyle'
Re: How long should a spin pole be? [Re: Andrew] #13681
12/04/02 10:18 AM
12/04/02 10:18 AM
Joined: Jul 2001
Posts: 57
J
Jacques Offline
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Jacques  Offline
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Joined: Jul 2001
Posts: 57
Longer is better, sure, but you have also to keep a reasonable steering balance. Too much leehelm due to a too long pole can be very annoying.

Re: How long should a spin pole be? [Re: Andrew] #13682
12/04/02 10:55 AM
12/04/02 10:55 AM
Joined: Jul 2001
Posts: 953
Western Australia
Stewart Offline
old hand
Stewart  Offline
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Joined: Jul 2001
Posts: 953
Western Australia
the 12s hold the best ratio pole to boat length..

try http://www.skiff.org.au/
12 foot hull up to 14 foot prods and up to 30 foot masthead kites

Re: How long should a spin pole be? [Re: Stewart] #13683
12/04/02 11:47 AM
12/04/02 11:47 AM
Joined: Jul 2001
Posts: 397
Burlington, Vermont USA
K
Kevin Rose Offline
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Kevin Rose  Offline
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Joined: Jul 2001
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Burlington, Vermont USA
[color:"brown"] >>the 12s hold the best ratio pole to boat length..

>>try http://www.skiff.org.au/
>>12 foot hull up to 14 foot prods and up to 30 foot masthead kites[/color]

Notice, too, the two sets of spreaders on the mast.


Kevin Rose N6.0na #215 Lake Champlain (New England's "west coast") Burlington, Vermont
Re: How long should a spin pole be? [Re: Kevin Rose] #13684
12/04/02 03:51 PM
12/04/02 03:51 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
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North-West Europe


And a set of spreaders on the spi pole 1

Not to mentions the excellent conditions of those maniacal sailors due to their watertime which is disproportional bigger than their air time ?

How many of us have tried to sail these exciting boats, and how many of those have succeeded at it ?

Mind you their is one for sale here in NL for only 800 euro's, I'm pretty tempted.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
And teh rating [Re: Wouter] #13685
12/04/02 03:56 PM
12/04/02 03:56 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
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North-West Europe

Australian PN system ratings called VYC

12 foot skiff 92,0

Taipan 4.9 73,5 (no spi)

Tornado 69,0 )no spi)

Big kites don't always make you faster.


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: And thats not fair W.. [Re: Wouter] #13686
12/04/02 10:45 PM
12/04/02 10:45 PM
Joined: Jul 2001
Posts: 953
Western Australia
Stewart Offline
old hand
Stewart  Offline
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Posts: 953
Western Australia
12 footer dies on waterline length against 16 foot boats.. A better comparison would be 12s vs Kitty Cats (can you look that up on the vyc yardstick dont have time)

16teens arent unlimited skiffs (neither is the 49er) So a fair comparison in the 16 foot length isnt available.. Although around the standard 49er course I doubt if that many cats will take one..

One can compare 18 footers vs F18HT and F18.. My guess is the F18 will lose the F18HT may be about the same or a little faster..

As for spreaders.. 12, Javelins(14 foot), 14s all have twin spreader rigs if not triple.. 16 & 18s have three or even 4 spreaders..

Re: And thats not fair W.. [Re: Stewart] #13687
12/31/02 11:40 AM
12/31/02 11:40 AM
Joined: Apr 2002
Posts: 591
Bradenton, FL
Sycho15 Offline OP
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Sycho15  Offline OP
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Joined: Apr 2002
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Bradenton, FL
This is all well and good but it's not giving me any of the answers I'm looking for

Don't you use a seperate hound for the 2nd headsail halyard?

For my specific application: I have a G-Cat 5.7M and I want to run a r/f reacher on it. The spin poles will be a V shape arrangement coming off the bow x-beam (beam not foil)

I've attached a (very) rough sketch of what I want to do. I'll be using two lower windsurfer mast sections.

Attached Files
14824-spinpole.jpg (68 downloads)

G-Cat 5.7M #583 (sail # currently 100) in Bradenton, FL Hobie 14T
Are you putting on the G-Cat? [Re: Sycho15] #13688
12/31/02 12:00 PM
12/31/02 12:00 PM
Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
dave mosley Offline
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dave mosley  Offline
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Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
I want to know how you do it so I can get some ideas. I havent been able to figure the best solution out with the front beam, but it seems that should be a benefit. I know the front tramp will be a benefit as you can sew a snuffer bag right to it.

Send me some pix when you get it going,

Dave mosley
G-Cat 5.0 # 507
www.seacats.org


The men were amazed, and said, "What kind of a man is this, that even the winds and the sea obey Him?" Matthew 8:27





Wouldnt the pole be better... [Re: Sycho15] #13689
12/31/02 12:06 PM
12/31/02 12:06 PM
Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
dave mosley Offline
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dave mosley  Offline
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Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
If you ran it from the main beam over the top of the front x-beam(where it could be supported side to side), then out a distance(to be decided) then supprted at the end by 2 side stays and a compression stay?

Dave Mosley


The men were amazed, and said, "What kind of a man is this, that even the winds and the sea obey Him?" Matthew 8:27





Re: Wouldnt the pole be better... [Re: dave mosley] #13690
12/31/02 12:40 PM
12/31/02 12:40 PM
Joined: Apr 2002
Posts: 591
Bradenton, FL
Sycho15 Offline OP
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Sycho15  Offline OP
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Joined: Apr 2002
Posts: 591
Bradenton, FL
Then I'd waste all the lounging room on the front trampoline and I'd lose a lot of jib sail-area by having to attach it high at the bridle instead of low at the bow-beam.

I'm going for- max sail area (light winds prevail around here in the summer) and max lounging area (beautiful women abound around here in the summer... )


G-Cat 5.7M #583 (sail # currently 100) in Bradenton, FL Hobie 14T

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