Whisker Pole Length Question

[kpgraci]

I've always read that a whisker pole should be 100% the length of the foot of the jib.

But according to another source (an article by Art Bandy in the book "The New Book of Sail Trim"), he says the pole should be the length of the foot but never less then 1.25 of the J measurement.

The foot of my jib is 10.5', J is 9', so 1.25 * J = 11.25'

So my whisker pole should be 11.25'? That seems a bit long to me., but then so does 10.5'.

Anyone ever hear about the J * 1.25 calculation?

Edit: After looking around the site, is seems longer is better, as one post put it, say 1.20 (20%) of "J". The 100% of "J" comes from racing restrictions apparently.

 

[rpwillia]

What are you using it for?

For racing a spinnaker pole is not legal if it is longer than your J. For a whisker pole I am not sure what rule applies, but I would think you would want it somewhat near the length of the foot of your jib to most efficiently pole your jib out.

 

[Ray T]

Re: What are you using it for?

I would reccomend a fixed length pole equil to J. What you should do is on a calm day unfurl or raise your jip then with the sail extended measure from the clue to the front of the mast allowing for some curve in the sail. This would really give you a better feel for what you need. I've had two boats with fixed length poles cut to J. The first boat a Cal 227 with a 155 genoa and my Hunter 216 with standard 100 jib and in both cases the J measurment was the correct one. I used to race my Cal and never felt the sail wasen't poled out far enough. I realize boats are different depending on make or model but I still feel J is the way to go. The reason I prefer a fixed length pole is that I feel it is more durable than a adjustable one.

 

[kpgraci]

No doubt I’m over thinking this or beating a dead horse or something, but I’m thinking again about whisker pole lengths.

I've read that the angle that the pole is set should be 180* to the boom, so that the boom and whisker pole form a straight line, as much as possible shrouds permitting.

So this implies there is a choice of what angle to set the pole at, but if the pole is fixed length it seems to me there is only going to be one angle actually achievable, and that will depend on the pole length and the jib foot length.

Now the jib is not cut square, so the horizontal distance from the tack to the clew is going to be less than the foot length. I don’t know this number for my jib without measuring, but I’m going to say that it is 10’ for my 10.5’ foot jib.

So I drew this to-scale picture showing the various jib and pole angles for different length poles. I sized the poles at J (9), Foot Length (10.5), and JX (11.25), which is J * 25%.

I also drew a gray line showing the straight-line path that would approximate the angle of the boom.

Now this assumes the jib is drawn tight and flat and this may be a bad assumption. In that case the red arc would be less than 10’, maybe more like 9’, and that would change the angles a bit.

So am I right in assuming there is no real angle adjustment possible, so this talk of matching the whisker pole to the boom is really the other way around, matching the boom to the whisker pole angle?

 

[Ron20324]

First off, in most cases a "whisker pole" is adjustable for length. And I would say probably, a "spinnaker pole" is always a fixed length (as racing rules), though a W.P. is used as a S.P.. The Forespar book says 'J' measurement is from the front of the mast at deck level to the headstay.

The pole length and angle to the wind would depend on the sail and what point of sail you are on. Preferred is that the pole would be parallel to the water, but not necessarily any relation to the boom angle. You may, in the future, go to a different sail or use the pole on a different boat and the adjustable pole is always a good idea.

Though i'm not crazy about twist-lock poles (and boat hooks), Forespar makes one from 6 to 12 feet in a couple of different styles.

 

[Bill Roosa]

I'm thinking the "180 degrees to the boom" is not right or that there are other restrictions. That would normaly put the WP slanting well forward and if you have a jib over 100% that would be a very long pole.

 

[Joe]

No doubt I’m over thinking this or beating a dead horse or something, but I’m thinking again about whisker pole lengths.

I'd just get an adjustable pole and rig it like a spinnaker pole with adjustable height mast ring, topping lift and foreguy... that will eliminate the indecision and give you tons of options.

I don't use the parallel to boom trim theory for trimming the whisker pole. The genoa is attached to the headstay so it doesn't move around like the spinnaker..... and besides you're just trying to pole it out wing and wing... so it's more like 120 instead of 180.

 

[Freedom77]

I have an adjustable whisker pole. If I am flying a 180% drifter then the pole has to be adjusted longer. If i am flying a 110% jib then it is, of course, shorter. If you are racing then you need to know what USYRU or YC rule says about legal length. If you can find a copy of SAIL POWER by Wallace Ross you can get good info. Hope this makes sense.

 

[RichH]

If a spinnaker pole or whisker pole is much larger than the J dimension, WHEN the pole, with full windloaded sail attached, 'slams' into the forestay the probably of making a 'hockey stick' out it increases exponentially.
;-)

 

[joker460]

Why not go here and select

http://www.forespar.com/whisker2011.shtml#H_LIST

 

[kpgraci]

I'm most likely going to pick up a Forespar adj 6-12. That's the 'standard' version as opposed to the heavy duty HD 6-12, which should be just fine, and considerable less expensive than the HD model.

I have access to some free 1.5 inch heavy wall aluminum tubing, but it's only 7'2" long, seems I need at least 9' or possibly 10'. Plus two Forspar ends would add up to more than the cost of the adj 6-12. Don't like twist locks, but it has the advantage of stowing easier than a fixed length pole.

compromise, compromise