Spinnaker Pole diameter?

[john_morris_uk]

This is a bit of how longs a piece of string but here goes.

I need one (or maybe two) new spinnaker poles for Serendipity. The J is 4880mm so these are not small.

I've had quotes for a single pole that vary between £2k and just under £300! These are for new poles from mainstream suppliers.

The variation seems to be in diameter of the pole. One has said a 96mm diameter pole would be the best but I might get away with a 80mm diameter pole. The £2k one said definitely 100mm and another main factory outlet said 80mm will be fine. (The latter being also the cheapest!)

I can have two poles and an extra car for the track on the mast for £600 if I go cheapest. I'm well aware that cheapest isn't always the best and you can buy cheap and buy again when the first ones break! The same supplier will provide two 100mm poles plus a car for about £1500.

I will need to add another spinnaker pole topping lift to the rig. (More slots in the mast...)

We don't get the spinnaker (or as Mrs M calls it, "The Bag of Fright") out when cruising two up as a kite that's 54' on the luffs is quite large for me to manage with Mrs M. However we do want to make provision for twin pole sailing downwind in the trades. Two genoas poled out wing on wing is my preferred option for trade wind sailing. The poles need to be man enough for this sort of work.

Any ideas or suggestions or opinions?

 

[Woodlouse]

What are they made of?

 

[sarabande]

weight and diameter.

Ian Nicholson, The Boat Data Book, Adlard Coles, indicates that "the larger the overall diameter of the [spi] boom, the more difficult it is to grasp in the hand. About 75mm (3in) is the biggest convenient diameter for most people. This fact may influence a choice towards a thinner maximum section with a thicker wall."


Now I know his book is 2003 edition, and rigging has improved in the last decade, but the anthropometric maximum is worth considering. Also with family handling the poles, and not always foredeck gorillas, the mass of the pole is important. Which ... leads.... me... trepidatiously to the suggestion of carbon fibre. Second hand ones from spar makers, where a racing pole end is smashed off, then mended ? Though cosmetically it's nice to have two poles which match, you might find one black one and one white one... or even a dirty grey one. They don't even have to be the same length, which on a downhill run might be an advantage if the wind is skewed off the stern.

And for the same diameter as alloy one, carbon is stronger and has more of a potential for use as a spare mast or sheerlegs. Handleability and multi-use would figure large in my specification.

 

[macd]

we do want to make provision for twin pole sailing downwind in the trades. Two genoas poled out wing on wing is my preferred option for trade wind sailing. The poles need to be man enough for this sort of work.

It may be that poles suitable for your spinny will be too long for twin genoas of the size you're likely to use in the Trades. With the twizzle rig (which is probably different than you propose, but broadly similar), the jibs are around 110%, and the poles roughly 90% of the mitre of each sail. This gives plenty of sail area, good speed and wonderfully balanced steering.

I'm certainly not promoting the twizzle rig to you (brilliant though it was, when set), but you might get some food for thought here and in the pages linked to: http://www.simetric.co.uk/twizzle_rig/equipment.htm

Of course poles can always be shortened. Stretching them's much trickier...

 

[john_morris_uk]

What are they made of?

Aluminium.

If you're like to sponsor me with a pair of carbon poles, then I'll send you the address to send them to.

You can have your company logo on the inboard end just underneath the piston release hank.

 

[john_morris_uk]

It may be that poles suitable for your spinny will be too long for twin genoas of the size you're likely to use in the Trades. With the twizzle rig (which is probably different than you propose, but broadly similar), the jibs are around 110%, and the poles roughly 90% of the mitre of each sail. This gives plenty of sail area, good speed and wonderfully balanced steering.

I'm certainly not promoting the twizzle rig to you (brilliant though it was, when set), but you might get some food for thought here and in the pages linked to: http://www.simetric.co.uk/twizzle_rig/equipment.htm

Of course poles can always be shortened. Stretching them's much trickier...

I've thought about a twizzle rig, but Pete Sanders talked me out of it.

In squalls, I've always just rolled away some of one or both genoas although one will probably be hanked onto an inner forestay. I've put the mast fitting in the mast for the extra forestay already.

 

[Sybarite]

I've thought about a twizzle rig, but Pete Sanders talked me out of it.

In squalls, I've always just rolled away some of one or both genoas although one will probably be hanked onto an inner forestay. I've put the mast fitting in the mast for the extra forestay already.

Why not go whole hog and get an aerorig? Would solve a lot of problems.

(Not to be taken too seriously).

I must say that I like the idea that they had on the older Amels. Short pole from the mast to the shrouds to which you attach (through an articulated joint) to a longer pole. This latter can swing back or forward to facilitate attachment to the sheets whilst standing on the side deck.. There is one on each side of the boat which you can attach to twin genoas which roll up together with the furler.

I'm not sure how efficient it is but I imagine it would be much easier to handle (with advancing years...) than a large spinnaker.

 

[chrishscorp]

Slightly different size....... but when i was thrashing around in a dinghy i made my own spinnaker pole out of carbon fibre all the bits were readily available off the shelf and just expoxied the fittings in the ends after putting some squirty foam in the tube a foot from each end to make sure it floated.......

 

[flaming]

The problem you're going to have with these poles is weight. If you go too heavy you'll end up having to winch them into place, which I would suggest will end up meaning you'll only ever end up using them on long legs, not on any sort of short trip. I did some cruising on a 48 foot old IOR swan where we had to winch the poles into position. As a result they barely got used in conditions when I'd definitely want one if it wasn't such a giant PITA to put one up.

But...

Go too lightweight and you'll end up bending them...

A slightly left field thought, but have you considered have 2 of different sizes? So one that's minimum spec (without being silly) and easy to put up for half an hour's kite fun in light winds and to take the smaller of your two jibs when both are polled, and one that's quite a bit heavier and robust for tradewinds running and kite flying in more boisterous conditions? I'm assuming with this that you wouldn't gybe the kite in conditions where you would be worried about the thinner pole, so having to twin pole gybe might not be a big issue.

 

[dancrane]

...when i was thrashing around in a dinghy i made my own spinnaker pole out of carbon fibre all the bits were readily available off the shelf...

Indeed? Which shelf? I'm keen to make myself a bowsprit - after years of Googling and asking at clubs, I've never been able to source a broken sprit to modify for my curious requirements, so I'd like to consider making my own.

 

[sarabande]

I'm glad Flaming has posted about mass, as well. Good point about having two of different lengths.

If there is no urgency about the matter, then leaving a card with the spar makers outlining a requirement for a damaged or secondhand CF pole could bring (cheap) results.

Alternatively build your own. Skills required are modest and you are a very practical person anyway. Masses of design and layup info on youtube.

https://www.youtube.com/results?search_query=carbon++mast+make

It's not rocket science any more.

 

[john_morris_uk]

The problem you're going to have with these poles is weight. If you go too heavy you'll end up having to winch them into place, which I would suggest will end up meaning you'll only ever end up using them on long legs, not on any sort of short trip. I did some cruising on a 48 foot old IOR swan where we had to winch the poles into position. As a result they barely got used in conditions when I'd definitely want one if it wasn't such a giant PITA to put one up.

But...

Go too lightweight and you'll end up bending them...

A slightly left field thought, but have you considered have 2 of different sizes? So one that's minimum spec (without being silly) and easy to put up for half an hour's kite fun in light winds and to take the smaller of your two jibs when both are polled, and one that's quite a bit heavier and robust for tradewinds running and kite flying in more boisterous conditions? I'm assuming with this that you wouldn't gybe the kite in conditions where you would be worried about the thinner pole, so having to twin pole gybe might not be a big issue.

That's a really good point.

I'm seriously tempted to try and build a couple of carbon poles. They'd look a bit out of place on my big fat cruising boat (11 tonnes on 39' is never going to be very quick and agile.) but I could always paint them or just not care...

 

[flaming]

That's a really good point.

I'm seriously tempted to try and build a couple of carbon poles. They'd look a bit out of place on my big fat cruising boat (11 tonnes on 39' is never going to be very quick and agile.) but I could always paint them or just not care...

If you think that's an option, I'd do that. Once you've sailed with a carbon pole it's very difficult to imagine going back to Aluminium.

 

[James Marinero]

You can get carbon fibre tube off the shelf (up to 80mm dia), though wall thickness could be an issue (3mm). You could always laminate an extra layer on. Given the figures you've quoted, it's not that expensive. No one has mentioned GRP - is that a possibility, or is it tooo heavy?

 

[TiggerToo]

but I could always paint them or just not care...

just paint one round stripe 25mm wide and 300mm from one end. It would then look very much appropriate to one of your "other" professions....

jokes apart: what did Sanders tell you about the Twizzle rig? I have always fantasised about it for a long downwind sail: what's wrong about it?

 

[john_morris_uk]

just paint one round stripe 25mm wide and 300mm from one end. It would then look very much appropriate to one of your "other" professions....

jokes apart: what did Sanders tell you about the Twizzle rig? I have always fantasised about it for a long downwind sail: what's wrong about it?

I just worked out you meant a white stripe. (I don't wear those style collars so it took a while.)

I've always been fascinated by the Twizzle rig but Pete said it wasn't worth the effort. He's supposed to know what's he's talking about....

 

[john_morris_uk]

You can get carbon fibre tube off the shelf (up to 80mm dia), though wall thickness could be an issue (3mm). You could always laminate an extra layer on. Given the figures you've quoted, it's not that expensive. No one has mentioned GRP - is that a possibility, or is it tooo heavy?

Z-spars sell end fittings at extremely reasonable prices. http://www.zsparsuk.com/#!spinnaker-poles/c1jfc

Their fittings for 80mm are for 2mm wall tube so even thinner... As the carbon pole people I've found supply poles for marine use I've banged an email off to them for prices and advice. http://www.carbonfibretubes.co.uk/

I suspect I ought to plan on stitching leather sheathes on appropriate areas for protection

 

[Javelin]

+1 for Z Spars.
They tend to give very good value,

 

[chrishscorp]

Indeed? Which shelf? I'm keen to make myself a bowsprit - after years of Googling and asking at clubs, I've never been able to source a broken sprit to modify for my curious requirements, so I'd like to consider making my own.

Im sorry it was too long ago for even me too remember who i purchased it from, I do remember it came in a standard length of 3M and i had to cut it down carefully. I have done a google search and tube is available on ebay and people like www.carbonology.com I am sure there will be others out there, have another look

If you want to use it on a dinghy do what i did and put some foam in either end, you dont want to spend hours sourcing and making it to watch it sink without trace

 

[awol]

As long as you use a bridle from the ends for any uphaul (or downhaul) the pole should only see compression forces and Euler's column formulae will give you an idea. My memory has diameter to the power 4 as a factor so doubling the diameter gives a 16x improvement to buckling ....... but it was so long ago!