Marshy 30 Posted December 20, 2010 Share Posted December 20, 2010 Seems around the right length too Murky, Although a 75mm tube is quite big, Think the SR pole is only 62 mm diameter. Means its bullet proof though Link to post Share on other sites
SanFran 12 Posted December 21, 2010 Author Share Posted December 21, 2010 At this stage Im starting to get abit confused, (which is not hard, really) because apart from the different jobs they do, what is the difference between a spinnaker pole and a whisper pole? Just the length? Or maybe no difference at all? Can I make my jockey pole into either (or both) just by adding a few feet? Link to post Share on other sites
Grinna 2 Posted December 21, 2010 Share Posted December 21, 2010 A spinnaker pole is a lot stronger than a whisker pole. That's because it has to deal with a lot more stress generated by the spinnaker. A spinnaker pole is attached to the front of the mast at one end. Its principle role is to position the tack of the spinnaker and its controlled by the brace that runs through the outboard end of the pole, by the downhaul that stops the pole from pointing at the sky, and by the topping lift that holds the pole up. A whisker pole is a lighter weight pole (to make it easier to handle) that is designed to be attached to the mast at one end (generally the same point as the spinnaker pole) and is clipped into the headsail sheet at the other end. Its usually controlled by the same downhaul and topping lift as the spinnaker pole. Most yachts don't have a dedicated whisker pole, they just use the spinnaker pole. A jockey pole is a short pole that attaches to the side of the mast at one end and extends past the side stays. The other end has the spinnaker brace running through it and its job is to keep the brace off the side stays to prevent sideways loads on the sidestays that tend to make the mast fall over. A jockey pole tends to have an outboard end fitting that's a bit different to a spinnaker pole (doesn't lock onto the rope) and is therefore not ideal. Many spinnaker poles are a simple aluminium tube with cast ends on each end. Some are more fancy and are tapered or made of more exotic materials like carbon to make them lighter and easier to handle. Link to post Share on other sites
SanFran 12 Posted December 21, 2010 Author Share Posted December 21, 2010 Ah.... he sees light! Yes, one end of the jockey pole is open, and not ideal. Anyone know if you can just buy a beak end? Link to post Share on other sites
Atom Ant 0 Posted December 21, 2010 Share Posted December 21, 2010 Yes you can. go to Sailutions in 44 Barrys Point Rd, Takapuna or phone them on 488 7605. Link to post Share on other sites
Murky 1 Posted December 21, 2010 Share Posted December 21, 2010 Ah.... he sees light! Yes, one end of the jockey pole is open, and not ideal. No. It's perfect. For a jockey pole. Grinna's explanation is right on the money - thought a diagram might complement it (inspired by FnG's diagrams on this site from time to time which add a lot). A jockey pole is used in addition to the kite pole when tight reaching, to keep the brace off the sidestays and often also the stanchions, and to add some angle to the brace so it is possible to winch it back without totally compressing the kite pole. But it won't ever be the kite pole, any more than you would expect an arm to become a leg. The section is too light, the end fittings are matched to the section, and as Grinna mentioned, the outboard end fitting is usually not completely enclosed, so that when the breeze moves aft and you "square" your pole (wind the brace back, so that it is no longer so close to the forestay) the brace conveniently pops out of the jockey pole because it is not needed. Probably worth jumping on someone else's boat for a few hours and running through all of this live. Link to post Share on other sites
SanFran 12 Posted December 21, 2010 Author Share Posted December 21, 2010 Good to know what the darned thing is for, cheers. Link to post Share on other sites
Atom Ant 0 Posted December 21, 2010 Share Posted December 21, 2010 As above with the good advice given. Don't bugger around with your jockey pole, but it sounds like you need a spinnaker pole too. Link to post Share on other sites
Murky 1 Posted December 21, 2010 Share Posted December 21, 2010 You did bloody well to get your kite setting like it is in your avatar without a pole at all. At the risk of complicating things further, a lot of cruising boats prefer an MPS-type sail, which is single-luffed (assymetrical), flown off your stemhead and doesn't require all the accompanying hardware that has been discussed so far in this thread. So it is an option worth considering to take the money that you would have spent on a kite pole and instead see if you could pick up a second-hand MPS at a reasonable price. There would be a lot less clanking and cursing on the foredeck. Still could be worth going out with someone else to see how these things work in practice. Link to post Share on other sites
SanFran 12 Posted December 21, 2010 Author Share Posted December 21, 2010 On looking for the right length of kite pole, is there any formulae, ie percentage longer than the mast to fwd stay distance? Link to post Share on other sites
PaulR 3 Posted December 22, 2010 Share Posted December 22, 2010 110% x J Go to www.Harken.com or Ronstan, Lewmar etc They all have good info re sizes, weights, SWL, BL etc and recommendations. Also pictures of boat measurements etc J = horizontal distance from front of the mast to the bottom of forestay at deck level. Link to post Share on other sites
PaulR 3 Posted December 22, 2010 Share Posted December 22, 2010 Once upon a time . . . . spinnaker poles were over 150%J. Then in 70's, Squadron had a limit of 125%J IOR, and now IRC, PHRF penalise if you are over 110%J Such is progress . . . Now I get offered Viagra from so many Canadian pharmacies. Happy to pass your email on to them. Link to post Share on other sites
Atom Ant 0 Posted December 22, 2010 Share Posted December 22, 2010 Chaps if I might say; The % of J you refer to is for various racing/handicapping requirements and has absolutely no relevance to what is the ideal pole length for a boat/spinnaker combination. Hence back to my original suggestion of measure the foot length and take that to Sailutions and ask for their opinion cos the ideal spinnaker pole length will be what makes it set best - not how it rates - which to a cruiser is meaningless. Spinnaker tube diameter will depend on a number of things some of which are the length of the pole, the size of the kite and the weight of the boat, and the type of boat it is. I.e in a gust does the boat simply load up or does it accelerate? Link to post Share on other sites
PaulR 3 Posted December 22, 2010 Share Posted December 22, 2010 AA: You are correct that I did not suggest the "IDEAL" length. So more info needed. Who made the Spinnaker? Was it made for this boat? How old in the Spinnaker? What shape is the spinnaker / cut of panels etc? Asking the sailmaker about this spinnaker, design intentions etc would be a good start. It might need the odd minor repair as well so useful to take the sail to the discussions. From the small avatar it does look like a full height, running spinnaker so presuming it is relatively recently made say in last 20 years. If so then most sailmakers were making spinnakers to fit current formulae for what most yachts needed for racing purposes. The current owner may be more cruising orientated now, but previously the earlier owner(s) may have done a race or two or more. So they, sailmakers and past owners, were most likely using a common formulae. The YNZ PHRF application form asks the following: LARGEST SPINNAKER IS: 0 Fractional OR 0 Masthead (tick one) Luff length: _________m Width – maximum:____________m Width - at half height: ____________m (shall not exceed 1.8 x 110% of J) * SPINNAKER POLE LENGTH: ____________m (shall not exceed 110% J) (if applicable) So working backwards, measuring foot length as you suggested, and the spinnaker width at half height will suggest a suitable overall pole length including fittings from the face of the mast, with the option of doing a race or two at some stage, be it only a cruising race. Good Luck and remember "measure twice, cut once". Link to post Share on other sites
SanFran 12 Posted December 31, 2010 Author Share Posted December 31, 2010 Bejeez... I just saw the price of the pole end bits for sale at Sailers Corner.... I'll put it on the next years Xmas list Link to post Share on other sites
SanFran 12 Posted December 31, 2010 Author Share Posted December 31, 2010 AA: You are correct that I did not suggest the "IDEAL" length.Who made the Spinnaker? Was it made for this boat? How old in the Spinnaker? What shape is the spinnaker / cut of panels etc? From the small avatar it does look like a full height, running spinnaker so presuming it is relatively recently made say in last 20 years. The YNZ PHRF application form asks the following: LARGEST SPINNAKER IS: 0 Fractional OR 0 Masthead Luff length: _________m Width – maximum:____________m Width - at half height: ____________m (shall not exceed 1.8 x 110% of J) * SPINNAKER POLE LENGTH: ____________m (shall not exceed 110% J) (if applicable) I have found someone who posted Spencer32 plans on www.boatdesign' forum. Have the sail plan for the original, which shows the spinnaker pole as being 4.12m (13'6"). Not to say that its the original spinnaker of course, but gives a good start point. Link to post Share on other sites
Atom Ant 0 Posted December 31, 2010 Share Posted December 31, 2010 Aha! It's a Spencer 32! Did I miss that bit of information somewhere along the line? John Spencer didn't really design his boats to any particular rule (ok there were a few but they were the exception) He went for long poles that were what he regarded as optimum for the job. So therefore your cheapest bet is to keep an eye on Trademe and buy any spinnaker pole that is longer than 12 foot. If it's 12 fot long it will be fractionally shorter than he specified but still long enough. If it's longer then you can shorten it. Try this. I have no idea if it's any good but it would be roughly the right length. You'll need to be quick though. http://www.trademe.co.nz/Browse/SearchR ... uggested=0 Link to post Share on other sites
PaulR 3 Posted December 31, 2010 Share Posted December 31, 2010 Possibly then John Spencer would of been using the RNZYS formula of SPL =1.25 x J. Back to measuring J. www.YachtingNZ.org.nz have a good diagram in their PHRF Rules document. Link to post Share on other sites
SloopJohnB 322 Posted December 31, 2010 Share Posted December 31, 2010 Once upon a time . . . . spinnaker poles were over 150%J. Then in 70's, Squadron had a limit of 125%J IOR, and now IRC, PHRF penalise if you are over 110%J Such is progress . . . Now I get offered Viagra from so many Canadian pharmacies. Happy to pass your email on to them. Sorry Paul IOR was 100%J without penalty. Link to post Share on other sites
PaulR 3 Posted December 31, 2010 Share Posted December 31, 2010 Thanks SJB. I could not easily find my very old IOR book to check. Link to post Share on other sites
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