Making up a tapered furling line

[stranded]

Want to try to take some friction out of the Genoa furling system and also get a more comfortable fit on the drum (Furlex 300s) when we revert to our 150% genny in the spring.

At the moment I can haul in by hand in most conditions but I really have to put my whole (considerable) body weight into it to get it moving, after which it is just a good workout. The boss though has to use the winch.

And the current 10mm line is a really tight fit in the drum such that any imperfection in hoisting and it rubs the insideso getting the first few turns of sail out can then be another tug of war.

I have done very little by way of splicing beyond lazy jacks, so just want to check the plan before I splash the cash…

1. is a 6mm dyneema to 12mm doublebraid tapered splice OK from the point of view of the integrity of the connection and and easy passage through the furling line blocks, which are under deck and so not accessible without removing headlining panels?

2. Would 8mm dyneema be significantly better from this point of view, and would it still yield a significantly smaller diameter on the drum.

3. I plan on dyneema to just forward of the deck organiser, which is just in front of the winch, which I think is about equal to J, then ‘sufficient’ double braid. If there is a reason I should have less dyneema, which, depending on the answer to 2. might mean I have to opt for 6mm to get the doublebraid to fit on the drum, what are the relative advantages/disadvantages of, say, 8mm dyneema = J against 6mm dyneema = 1/2J?

Does this make sense? Would it work? And what should I be doing.

If it does work then I might try a similar with the single line reefing lines…

Thank you in advance for any advice.

 

[Minerva]

Think going tapered would be pointless - you'd soon run out of the thick part and be hauling away on the thin part.

We've just gone for 6mm for the whole length and it's fine - a couple of turns round the spinnaker winch to act as ratchet and haul away. Your hands will harden up soon enough and get used to it.

 

[stranded]

Think going tapered would be pointless - you'd soon run out of the thick part and be hauling away on the thin part.

We've just gone for 6mm for the whole length and it's fine - a couple of turns round the spinnaker winch to act as ratchet and haul away. Your hands will harden up soon enough and get used to it.

That’s what I am struggling to get my head around. My thinking is that if the dyneema is the length of the foot of the sail then it would not come through the clutch and all hauling would therefore be on the thicker line. Is that wrong headed? No way would I be able to pull in 60m2 of genny by hand with 6mm string in a blow, nor would the clutch hold it nor the winch wind it.

 

[Poey50]

I had a similar issue on a Furlex 200S. The original 8mm line had gone thicker with age. I used 5 mm dyneema spliced to new 8mm braid on braid. It works fine - much smoother. Getting the sheath of the 8mm line into the dyneema was not easy though, 6mm dyneema would have been easier.

 

[Talulah]

Our furling line is not tapered but has the core removed for about 50% of its length. Easy to make.
Take a 10mm line the same length as your existing. Attach one end to something solid and hold it out straight. At the other end hold the core and push back the outer sleeve for as much as you can. Cut the exposed inner core off. Then pull back the outer sheave. Feel where the core ends and fix it at this point by sewing it in. Sew The other end so the outer sleeve doesn’t fall apart.
No issues stowing on the Furlex. And enough full line to comfortably grip when furling.

 

[Wing Mark]

The line on the drum is a lot longer than the foot of the sail.
So the space saved by the dyneema on the drum may be more than compensated for by the 12mm rest of the line.

I think some people just take the core out of the line which never meets the clutch, so it becomes a hollow braid which flattens on the drum?
The cover of 10mm rope is probably strong enough, although not every rope has the same core:cover ratio.

If the drum is just about big enough now, changing a portion of the rope to cover only or thinner dyneema may make all the difference?
5mm dyneema would only have 25% of the volume of the 10mm, if you change say 1/3 of the line, you'll gain noticeable space on the drum.

Changing the whole thing down to 8mm cruising dyneema would be (about!) 64% of the volume, loads of space on the drum.

The tail end, which never goes on the drum can be fat as you like, if the hardware will cope. That's the bit you pull on with full sail against you, but maybe not what you're pulling on in stronger winds. You can make that tail longer by leading the line via the stern instead of shortest route to the halyard winch.
A less straight route might add more friction though!

 

[stranded]

Thanks all - very helpful. I need to get down with my tape measure don’t I. I’m a bit nervous of just relying on a double braid cover - is it possible to ascertain the break strain of just the outer? Or what about the reverse approach of taking the cover off a cruising (or even racing) dyneema? Might help more with the friction?

 

[Sandy]

Good lord my halyards and sheets are 10mm, a 6 mm line should be more than adequate. It is not as if there is any weight on the furling line - if there is you are doing something wrong.

 

[stranded]

Good lord my halyards and sheets are 10mm, a 6 mm line should be more than adequate. It is not as if there is any weight on the furling line - if there is you are doing something wrong.

Hi Sandy - it’s not the strength (of the dyneema) that I’m worried about but whether too thin, or with too big a step, might cause trouble going through the (under deck) blocks.

 

[thinwater]

a. The no-core portion is not long enough to reach the winch or your hands. You will never handle the skinny part. In fact, you need remove only enough core to improve the fit on the drum, perhaps only 8-12 feet. Depends on the boat, but stripping a length equal to 80% the foot of the jib is a good starting point.

b. All conventional double braid ropes are 50% cover and 50% core. If they were not, a conventional doublebraid eye splice would not work (since the cover carries the load on one leg).

c. Tough hands comments crack me up. I could do thing the hard way. Sailors learn to do things the smart (easy) way. Tapering furling lines is easy.

Do taper the core end and do lock-stitch the transition.

 

[mikegunn]

Want to try to take some friction out of the Genoa furling system and also get a more comfortable fit on the drum (Furlex 300s) when we revert to our 150% genny in the spring.

At the moment I can haul in by hand in most conditions but I really have to put my whole (considerable) body weight into it to get it moving, after which it is just a good workout. The boss though has to use the winch.

And the current 10mm line is a really tight fit in the drum such that any imperfection in hoisting and it rubs the insideso getting the first few turns of sail out can then be another tug of war.

I have done very little by way of splicing beyond lazy jacks, so just want to check the plan before I splash the cash…

1. is a 6mm dyneema to 12mm doublebraid tapered splice OK from the point of view of the integrity of the connection and and easy passage through the furling line blocks, which are under deck and so not accessible without removing headlining panels?

2. Would 8mm dyneema be significantly better from this point of view, and would it still yield a significantly smaller diameter on the drum.

3. I plan on dyneema to just forward of the deck organiser, which is just in front of the winch, which I think is about equal to J, then ‘sufficient’ double braid. If there is a reason I should have less dyneema, which, depending on the answer to 2. might mean I have to opt for 6mm to get the doublebraid to fit on the drum, what are the relative advantages/disadvantages of, say, 8mm dyneema = J against 6mm dyneema = 1/2J?

Does this make sense? Would it work? And what should I be doing.

If it does work then I might try a similar with the single line reefing lines…

Thank you in advance for any advice.

The instructions that come with Hood furling gear say to remove one third of the core of 10mm braid on braid line.
It's very easy to do this by opening up the cover at a point 1/3 of length from end and withdrawing 1/3 of core. Cut off the removed core close to the cover and milk the stub end back inside the cover. There is no need to attach the core to the cover.
Fix coreless end of line to the furling drum. If foresail is still furled put say, three or four turns around drum to allow for any future stretch of line, otherwise just load up drum with all spare line.
The big advantage of this arrangement is that the coreless line lies flat as it loads onto the drum when unfurling the sail. This precludes the risk of turns collapsing on the drum and causing a lock-up.
I've had two 12m yachts using this arrangement, only one of which was fitted with Hood gear and had no problems furling by hand, despite being a comparitive weakling.
Mike

 

[Wing Mark]

Good lord my halyards and sheets are 10mm, a 6 mm line should be more than adequate. It is not as if there is any weight on the furling line - if there is you are doing something wrong.

The load on the furling line will be significant when roller reefed in strong winds.
Roughly the tension in the jibsheet divided by the ratio of the diameters of the turns on the drum vs the diameter of the half rolled sail.
So something of the order of half the sheet tension, including when the boat is hit by gusts etc.
That is I think quite a lot on a boat bigger than mine.

 

[dunedin]

Good lord my halyards and sheets are 10mm, a 6 mm line should be more than adequate. It is not as if there is any weight on the furling line - if there is you are doing something wrong.

It is not just a furling line but a genoa reefing line - in a Force 7 when part reefed and winching in the sheet to go to windward there is an awful lot of strain on the reefing line - opposing the sheet forces trying to unfurl it.
We use cruising dyneema for the jib reefing line for this reason. There is plenty of room on our furler, but if we needed to taper it I would go for removing the cover on the front part, leaving the dyneema core.
As ever, things will vary based upon boat and sail size - but the OP did refer to a large overlapping genoa so will likely need to reef it fairly frequently.

 

[mikegunn]

It is not just a furling line but a genoa reefing line - in a Force 7 when part reefed and winching in the sheet to go to windward there is an awful lot of strain on the reefing line - opposing the sheet forces trying to unfurl it.
We use cruising dyneema for the jib reefing line for this reason. There is plenty of room on our furler, but if we needed to taper it I would go for removing the cover on the front part, leaving the dyneema core.
As ever, things will vary based upon boat and sail size - but the OP did refer to a large overlapping genoa so will likely need to reef it fairly frequently.

I would agree with you that the furling line is put under strain if sailing with a reefed foresail, but how much is open to discussion. I've just measured my furling drum and the mechanical advantage when the drum is nearly full would appear to be about 4:1. The breaking strain of polyester braid on braid is approx. 2500 kg. With the core removed that reduces to1250 kg. That's still over a ton, metric or Imperial! So, if working the line to its limit it would be possibleto impart a torgue of 5000 kg on the sail's luff groove. In my experience I have never seen a furling line or sail clew subjected to anything like that tension when reefed. I suspect that if it were other components in the system like guide blocks would fail first. Of course, when furling it is normal to offload the sheet anyway.
If anyone has found any information on real world, measured loads on sheets, furling lines etc I for one would be very interested.
Mike

 

[Sandy]

It is not just a furling line but a genoa reefing line - in a Force 7 when part reefed and winching in the sheet to go to windward there is an awful lot of strain on the reefing line - opposing the sheet forces trying to unfurl it.
We use cruising dyneema for the jib reefing line for this reason. There is plenty of room on our furler, but if we needed to taper it I would go for removing the cover on the front part, leaving the dyneema core.
As ever, things will vary based upon boat and sail size - but the OP did refer to a large overlapping genoa so will likely need to reef it fairly frequently.

Then I must be doing something wrong! I have a 140% genoa and can reef quite easily in a F7 using 6 mm furling line. Can't quite remember @stranded's boat length as its been a while since we met up, perhaps a chat with one of the two excellent sail lofts within 5 nm of his home might solve the puzzle.

@stranded we must meet up next summer and discuss trott mooring techniques as I've moved to Saltash and will be well versed in the tricks of the Tamar early next season.

 

[stranded]

I’ll talk to the riggers at Darthaven when we come out the week after next, but overall I’ll take a view based on advice here - it is forming.

sandy - yes - back on our mooring beginning of April and always happy to discuss the devil that is trot mooring. Or, frankly, anything else - the only important thing is the dram that the conversation takes place over.

 

[Sandy]

sandy - yes - back on our mooring beginning of April and always happy to discuss the devil that is trot mooring. Or, frankly, anything else - the only important thing is the dram that the conversation takes place over.

I'll look forward to it. I expect to be round to the Dart early in the season. I'll bring a bottle.

 

[dunedin]

Then I must be doing something wrong! I have a 140% genoa and can reef quite easily in a F7 using 6 mm furling line. Can't quite remember @stranded's boat length as its been a while since we met up, perhaps a chat with one of the two excellent sail lofts within 5 nm of his home might solve the puzzle.

@stranded we must meet up next summer and discuss trott mooring techniques as I've moved to Saltash and will be well versed in the tricks of the Tamar early next season.

It’s not the putting in of the reef that puts the reefing line under strain (the sheet will be eased, and on a bigger boat probably turn downwind) - it is the grinding in of the genoa sheet and the bashing upwind, both of which are trying to unfurl the sail.

 

[thinwater]

I have measure the tension on a furling line when roller reefed. Yes, it is a considerable fraction of the sheet load, which can be tons. Dundin was basically correct. Sandy, just think about the maths. Furling and sailing reefed with the sheet bar tight are two different things. When sailing reefed the furler line is bar-tight. Then to furl I head off the wind and pull it in with a single turn on the winch just fore safety, no strain.

That said, the load is 3-5 times less than the sheet load, so a line one size smaller than the sheet, with the core removed, is still enough. But you will need to watch chafe near the drum. It's under a lot of tension and wears easily. Maxijacket helps.

 

[differentroads]

...The breaking strain of polyester braid on braid is approx. 2500 kg. With the core removed that reduces to1250 kg. That's still over a ton, metric or Imperial!...
If anyone has found any information on real world, measured loads on sheets, furling lines etc I for one would be very interested.
Mike

Some of the sailmakers, winch manufacturers and ropemakers have sheet load calculators eg Harken at
Genoa System Loading Calculator | Harken Marine
My 28sqm jib in 30kn wind (when I'm very very late with the reefing!) comes out at 500kg sheet load. Don't forget to put in the reefed sail size to get realistic loads at high wind strengths.

My 10mm braid on braid is said to have a breaking strain of 2600kg. Lets say a safe working load of one third - 870kg and halved again when thinned to just the cover - 435kg. So it could handle full sheet load, in theory

So my question is, how does sheet load relate to furling line loads? Well, you'd have spilled most of the wind while reefing, so considerably less than the sheet load, I presume.