Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 22-08-2008, 04:52   #1
Registered User
 
miss-m's Avatar

Join Date: Apr 2008
Location: Southampton, UK
Boat: Hartley Queenslander 36
Posts: 58
Talking Pole size

Calm down Gentlemen please.

We have an asymmetric spinnaker and a furling genoa. We would like a pole to help on the downwind passages. We have seen some quite cheap on ebay and juust wondered- how long should the pole be? I've looked for a set formula but cant seem to find one.

Any ideas gratefully appreciated. Thanks all
__________________

__________________
People who say things can't be done should stop getting in the way of the people doing them.....


www.concretefloats.com
www.sailingmissmoneypenny.com
miss-m is offline   Reply With Quote
Old 22-08-2008, 05:39   #2
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,321
As with most things on boats, pole length is a trade-off, with ease of handling, storage, avoidance of breakage, and sailing performance as the parameters. Traditionally, most racing rating rules have assumed a standard pole length is equal to "J", or the distance from the mast to the tack of the genoa. This is based on using symmetric spinnakers.

If you are starting from scratch, a slightly longer pole, say 110-120% of J may be better for poling out the genoa, depending on the size of the sail. I have a standard pole and a 125% genoa, and I find the pole limits me from sailing wing-on-wing to apparent wind angles of less than 130 degrees unless I partially furl the genoa.

The asymmetric spinnaker can be tacked through the end of the pole just like a symmetric one, giving more power downwind. However, if you are sailing short-handed, you may find yourself using the poled-out genoa much more often, as it can be quickly and easily doused on the roller furler if the wind comes up.
__________________

__________________
donradcliffe is offline   Reply With Quote
Old 22-08-2008, 05:45   #3
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
The luff of an asymmetrical spinnaker is about 15% longer than the leech, and the sail has an airfoil shape. Many cruisers prefer an asymmetrical spinnaker because a spinnaker pole is not necessary to fly the sail. Usually, the asymmetrical spinnaker is tacked to the boat's bow fitting and used poleless as a very big genoa; the asymmetrical spinnaker is best used broad reaching and as tight as 75 degrees to the true wind. Using an asymmetrical, it is necessary to "tack" downwind (gybe at roughly 90 to 120-degree angles) to fly the sail successfully.

Demystifying the Asymmetric Spinnaker

http://www.monmouth.com/~nsnj/demystasym.htm
and
http://www.northsails.com/north_amer...4Questions.htm

Refining Your Downwind Sails
http://www.airforcesails.com/refinin...wind_sails.php

Cruising with an Asymmetrical Spinnaker
http://www.cncphotoalbum.com/doityou.../spinnaker.htm
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 22-08-2008, 06:00   #4
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Miss-M,

I have a Forespar "line control" whisker pole that's adjustable in length. The fact that it can be extended for use with the sail allows for easy storage and handling. I use it for poling out the genoa. Haven't tried it on the asymmetric spinnaker yet.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 22-08-2008, 06:22   #5
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
Generally, an adjustable Whisker Pole, about equal to J, or a little shorter (collapsed) extending to 120-125% of J will accommodate a range of sails & conditions.

Forespar on Whisker Poles:
http://www.forespar.com/resources2/t...eSeminar.shtml
and:
http://www.mauriprosailing.com/Fores...sker-Poles.htm
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 22-08-2008, 07:55   #6
Registered User
 
svHyLyte's Avatar

Join Date: Mar 2006
Location: Tampa Bay area, USA
Boat: Beneteau First 42
Posts: 3,432
Images: 25
I would not recommend using an extendable whisker pole on an asymmetric. The tack line loads the pole at a relatively flat angle and the resultant loading can be quite dramatic—more so than the poles are designed for (I believe Forespar offers the same advice).

As an alternative, measure the distance from the mast to the point forward of the pulpit necessary to get a fair-lead from the end of the pole to the tack block and select a fixed pole on the basis of that length as a J dimension.

Coincidentally, most asymmetric's can be flown pretty effectively down to about 160º, one will find that gibing down-wind will allow one a much better VMG than will a dead run with the added distance being easily off-set by the gain in speed. Moreover, the yacht will roll far less making life far more comfortable for the crew.

FWIW…

s/v HyLyte
__________________
"It is not so much for its beauty that the Sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
svHyLyte is offline   Reply With Quote
Old 22-08-2008, 07:59   #7
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Quote:
Originally Posted by svHyLyte View Post
...most asymmetric's can be flown pretty effectively down to about 160º, one will find that gibing down-wind will allow one a much better VMG than will a dead run with the added distance being easily off-set by the gain in speed. Moreover, the yacht will roll far less making life far more comfortable for the crew...
That's been my experience. Plus, "tacking downwind" allows you to enjoy some breeze over the deck. More comfortable than sailing DDW.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 26-08-2008, 09:56   #8
Registered User
 
miss-m's Avatar

Join Date: Apr 2008
Location: Southampton, UK
Boat: Hartley Queenslander 36
Posts: 58
Ok, we're getting there. Honest. Thanks for all your replies.
Next questions is: Does it matter at what height you put the ring on the front of the mast?
Does that make sense? We can't have a track which the pole stays on permanently, so we're fitting a ring. But how high/ low should we put it? Or does it really not matter and I'm overcomplicating the whole thing?? And also, there seem to be a never ending combination of ends for the pole- does it matter overly which ones we use?

Thanks again
__________________
People who say things can't be done should stop getting in the way of the people doing them.....


www.concretefloats.com
www.sailingmissmoneypenny.com
miss-m is offline   Reply With Quote
Old 26-08-2008, 12:45   #9
Registered User

Join Date: Mar 2008
Location: Houston TX
Boat: Pacific Seacraft 25 "Turtle"
Posts: 364
Images: 35
I have a Tacker........

You might take a look at a product called the ATN Tacker. I have one and find it works well for me. I sail mostly solo and wanted a simple spinnaker system. Using the snuffer makes the whole process pretty easy.

I have nothing to gain from the sales of any ATN products I'm just a happy owner.

As for ring height I think the pole should be higher at the mast than the sail. If you have a track you can use multiple sails with differing clew heights.........martin


www.atninc.com/index.htm
__________________
I must go down to the sea again.........
cantxsailor is offline   Reply With Quote
Old 26-08-2008, 13:22   #10
Registered User

Join Date: Jan 2006
Location: North Carolina
Boat: 44 footer
Posts: 923
I read something interesting the other day in regards to pole height...

In John Guzwells Trekka Around the World, he talks about mounting the pole 6 feet above the deck, allowing the sheet angles to take some of the load from the pole and letting it be a bit more tame. Then again he talks about using nylon guys and sheets too... So I bet theres a bit of give/stretch that isn't seen in the stuff used today.

Don't know how well it scales up, as Trekka is only what... 20 feet long? But it seemed like a cool idea to cut down on some complexity.

Zach
__________________
Zach is offline   Reply With Quote
Old 27-08-2008, 03:52   #11
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
Quote:
Originally Posted by miss-m
... Does it matter at what height you put the ring on the front of the mast...
Both Forespar & Mauri Pro address this question, as previously linked:

Forespar on Whisker Poles:
http://www.forespar.com/resources2/t...eSeminar.shtml

and:

http://www.mauriprosailing.com/Fores...sker-Poles.htm
__________________

__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Regular Spinnaker without a pole? paulgauche Seamanship & Boat Handling 6 16-06-2008 16:39
Mounting A Radar On A Windgen Pole?? Hubec Marine Electronics 3 04-03-2008 20:01
Spinnaker pole storage. Zach Monohull Sailboats 18 16-10-2007 09:10
Whisker/Spinnaker pole advise Greg S Seamanship & Boat Handling 6 23-07-2007 06:05
Why would a MOB pole be orange?? Alan Wheeler General Sailing Forum 65 22-01-2006 18:42



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.