spinnaker shhet/guy sizing

laika

laika

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I have a spinnaker I've never used. I have no sheets/guys (do have pole/halyard/uphaul and probably something I could use as a downhaul). I've never used a spinnaker on my own boat so have never bought running rigging for them before. As my (one) novice crew has finally built up the confidence to tweak sails I think the time has come, especially as I'm going shopping at the boat show on Monday.

For my 12m boat Jimmy Green's sizing guide suggests 10-14mm braid on braid sheets and 16mm guys, both at 1.5xboat length (i.e. 18m). Does that sound right, are fancier fibres worth it and if so, what sort of size would I be looking at?

Boat is heavy, we don't have racing pretensions and the plan is blue water cruising. Stretch (within reason) probably isn't critical but lightness is always handy as is not falling apart in UV. If we can't get on with the spinnaker 2-handed we'd probably be wanting to use the same sheets on a cruising shute / gennaker. Advice appreciated.
 
12mm should be ideal for sheets & guys. You could get away with 10mm on the uphaul/downhaul, but it's easier to just buy a roll of 12mm and do it all with that.

Forget the fancy stuff, just buy the cheap braid on braid. 1.5 x LOA is about right for sheet/guy length.

an easy way to do the sheets and guys is to cut a length 3 times LOA and then slide a swivel snap-shackle up to the middle, and then just tie an overhand or lock knot up by the shackle. Then you have no ends to come undone.
 
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If you are likely to let the guy fly when dropping 2x boat length is about right to stop the ends going through the blocks - I stick by the adage of no stopper knots in sheets or guys. Bobc's idea of halving the rope to provide sheet and guy stops you dropping the guy in light weather or using it for your gennaker/cruising chute.
 
For my 12m boat, we have 12mm sheets and guys, braid on braid. Originally I had both sheet and guy ( different colours) onto one snap shackle but soon had them separated. It can be quite convenient if things go badly to be able to take one off the sail and leave the other on.

It has to be very light airs for just me and one crew to hoist it (mast head) on the basis that once its up it has also got to come down again ! Then the two lines are too heavy and drop the clew down too low for the sail to be effective, so another reason to be able to remove the lazy guy. Also to help, I have also bought one sheet of 6mm braid on braid, dyneema is better if you can afford it. I don't bother with a snap shackle on this, just tie a bowline onto the sail.
 
I'd go 2 times boat length. 12mm seems a bit big and it will be very heavy in light airs (and short term it does not sound as if you will be using it in stronger winds). The fact one is a guy and one a sheet does not matter, I'd have them both the same and then you can swap them. You only need 12mm (or 10mm) to make them easy to handle - as said if you can afford it I'd actually go for 6mm Dyneema (which will not drag in the water in light winds) but with bigger tails (for ease, comfort, of handling). I'd use easy release snap shackles, tight, wet bowlines might be slow to undo, if you need to free the spinnaker up quickly. The halyard would be best braid on braid - it has a bit of give in it.

To reduce chance of scaring the crew, until they get used to it - a sock would be a good investment.

Jonathan
 
I think dyneema would be a waste of money & hard on the hands. A bit of stretch on a spinnaker sheet is not a big deal, like halliards
Remember that 8mm braid will have enough breaking strain for what you need & comfort on the hands & good winch grip is important so i would go for max 10mm

As for the sock suggestion- forget it, learn to use the sail properly - My sock now lives in the garage ,after so much hassle with the d..d thing , causes more problems than it solves
A couple of hoists in lighter airs & you will soon get to work the spinnaker properly. Plus it is much quicker to hoist & drop without the sock & safer
 
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Daydream,

With a sock I can fly a spinnaker, 75 sq m, singe handed. I would never fly one, single (or short) handed without one. It would simply be impossible to retrieve. I appreciate this is not proper, in your book, but it works. Maybe you did not learn how to use the sock properly?

You sound as if you want to deny short handed yachtsmen the opportunity to use them. Are you equally against gennakers because they are not proper sails?

Jonathan
 
J Neeves said:
You sound as if you want to deny short handed yachtsmen the opportunity to use them. Are you equally against gennakers because they are not proper sails?

Jonathan
Click to expand...

Actually I wrote it as a single hander, --just finished second uk circumnavigation SH ... 90% of my sailing is single handed
Perhaps being 67 yrs old means I am too long in the tooth to learn , having done several years on a large yacht as foredeck skipper in my 30's
If you want to see how its done I am off to Dieppe tomorrow from Bradwell, then possibly up to Eastbourne & home
The chute will get well used if the opportunity arises
 
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For guys I would go with the same size as your genoa sheets - my own preference is for 12mm because I don't like handling 14mm (too stiff and unwieldy).

Spinnaker sheets are somewhat different as you tend to keep those in hand for a lot of the time rather than cleating them off - I use 10mm at the moment but I think 12mm is probably better.

1.5x is fine for the guys but for the sheet I would go for 2x - if you are sailing seriously you sometimes want to be able to take the sheet forward to the shrouds so you can see the sail properly
 
Thanks for all the advice which I will take with me to the show tomorrow. Will also chat with staff at Jimmy Green. Thanks also to daydream believer for the offer of a demo but I have to be back at work tuesday. It's sounding like 12mm braid on braid and I guess that 4x25m would be a convenient 100m roll, although different colours would have been nice. First time out I'll be taking an experienced racer pal with me and make a call on a sock after that, though I suspect that anything that makes things less stressful will be a good thing.

I hadn't actually thought about shackles as mentioned by Jonathan. Any further thoughts on those? I note that they're hideously expensive.
 
If you are only cruising with a spinnaker then there is no reason why you need sheets and guys. I doubt if you would consider using a spinnaker in anything stronger than a force 4, so save some money now as you can always add guys later if you think you need them. I sail single handed and have set the spinnaker, but I only use sheets. A gybe is easy if you end to end the pole, releasing the pole from the mast moves the sail behind the main (I am ¾ rigged). Once the lee side has the pole connected, you can release the windward pole end and fix to the mast and then gybe the main. It will not be to a racing perfection, but is simple and quick to do without another pair of ropes in the cockpit.
 
laika said:
... I guess that 4x25m would be a convenient 100m roll, although different colours would have been nice.
Click to expand...

Jimmy Green do 50m deals, and I would highly recommend different colours, and it will be hard to tell a sheet from a guy if the cockpit turns itself into a ropes nest / knitting contest.
 
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