Stretchy main halyard

I'm not arguing that polyester stretch is not annoying. But the OP reported 20 inches, not 2 inches. For 20 inches of stretch on a smaller boat, (36' mast) something is slipping. That is ... obvious. I'm also sure in my bet that he does not have modern sails, but rather cross cut polyester. I seriouls doubt he is enough of a sail trim maven to have noticed a few inches of stretch, assuming the halyard was well-tension at the start.
 
All I can say is that my day boat has cross cut polyester sails, and on that, 2mm is where the crucial line is drawn. Dyneema halyards, cascade tensioners, all ropes marked, it’s an obsession. It makes you realise how much difference good trim makes. That’s why we do it on our cruising boat, and probably why half the boats we pass are awestruck by the upwind speed. The difference would be much less marked if they had dyneema halyards and used them correctly.
 
dunedin said:
If your halyard is only 25 metres it must be a very small boat? Would 8mm be better?

Irrespective I would (and do on a much bigger boat) use this halyard knot which works well. Jeanneau Halyard Hitch - Jeanneau Owners Network
Even if lost some strength, could probably pick your boat up with it
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We use our main halyard to pick up our 40kg engine off the engine bracket and move it to the dinghy. We also use it to pick up the dinghy with engine and fuel tank and lift it on to the deck. Weight about 120kg. A bowline works fine. I have been doing it for years. It's easy to tie and undo.
thinwater said:
You are talking about 1.6% stretch. The OP is talking about 7% stretch. Not the same. I'm also guessing your halyards are operating at a higher % of BS than his, since you have a larger boat and the halyard was probably not up-sized in proportion. So yes, what you saw was the stretch I would calulate. He is seeing 6-8x more than you would calculate (allowance for different load factor, otherwise 4x more).

There is also something wrong with your polyester, either age, quality, or size. I have used polyester (and Kevlar and Dyneema) and it is not that bad. It should be no more than 1% at working load, or about 5-6 inches, and usually less if the line is sized properly. And that is the stretch from zero to full load. The actual change AFTER pretension should be only a few inches. Still a problem for sail trim, but not the 30 inches the OP described. There is another problem.

Not the same experience.
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Three polyester Halyards all with the same huge stretch. Nothing wrong with them. It's just my experience of polyester. All three were 12mm. Dyneema replacement are 10mm
 
thinwater said:
I'm not arguing that polyester stretch is not annoying. But the OP reported 20 inches, not 2 inches. For 20 inches of stretch on a smaller boat, (36' mast) something is slipping. That is ... obvious. I'm also sure in my bet that he does not have modern sails, but rather cross cut polyester. I seriouls doubt he is enough of a sail trim maven to have noticed a few inches of stretch, assuming the halyard was well-tension at the start.
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i agree - 20 inches, if it's really that. is too much to be just stretch on that length of line.

something else is going on
 
Laser310 said:
i agree - 20 inches, if it's really that. is too much to be just stretch on that length of line.

something else is going on
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Our XOD halyard stretched a good 10” before we ditched it. The luff is about 23ft, so maybe 28ft of rope being stretched by a polyester sail. Only 6mm cos that’s the max that will fit though the masthead sheave.
 
geem said:
We use our main halyard to pick up our 40kg engine off the engine bracket and move it to the dinghy. We also use it to pick up the dinghy with engine and fuel tank and lift it on to the deck. Weight about 120kg. A bowline works fine. I have been doing it for years. It's easy to tie and undo.
Three polyester Halyards all with the same huge stretch. Nothing wrong with them. It's just my experience of polyester. All three were 12mm. Dyneema replacement are 10mm
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Agreed. But the OP is seeing 4-6x more stretch. He has a slipping clutch. Not even nylon would stretch that far.

I've had wire, Kevlar (30 years ago) and Dyneema halyards. I have carbon/film sails on my trimaran with a Dyneema halyard. I understand. You are preaching to choir on that.

Polyester DB ranges from 0.6-1.2% stretch at 10% BS, depending on the weave. For example, Samson varies from XLS to Trophy; both are high quality polyester DB, but the stretch is about 50% greater for Trophy, because of a looser weave. And in fact, XLS is what Samson recommends for cruisers (the OP). Other grades of polyester, and from other manufacturers, may be less satisfactory.

Samson Rope Guide--pages 3-4
 
Chiara’s slave said:
Our XOD halyard stretched a good 10” before we ditched it. The luff is about 23ft, so maybe 28ft of rope being stretched by a polyester sail. Only 6mm cos that’s the max that will fit though the masthead sheave.
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In other words, it was undersized. 6mm is floss in polyester. Definitely a good application for Dyneema. My first Kevlar halyard was on a Stiletto 27 (1200-pound catamaran) with a similar block limitation (because it had been wire). Huge improvement.
 
Chiara’s slave said:
And 1% is too much. That’s 100mm on a 10m luff. That is utterly hopeless for windward work.
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Think this through.
  • I didn't say you were at 10% BS. More likely the peak tension is about 7% max for good design and long life.
  • You are neglecting pretension, which is probably half of the full load tension.
So the actual stretch is less than 1/2 of 100mm, or 30-50 mm. 1.5 inches. Still not perfect. But a cruiser WON'T CARE. The sails are 15 years old and gagged out anyway. New wine in old skins.
 
thinwater said:
Think this through.
  • I didn't say you were at 10% BS. More likely the peak tension is about 7% max for good design and long life.
  • You are neglecting pretension, which is probably half of the full load tension.
So the actual stretch is less than 1/2 of 100mm, or 30-50 mm. 1.5 inches. Still not perfect. But a cruiser WON'T CARE. The sails are 15 years old and gagged out anyway. New wine in old skins.
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Some of us don’t treat our cruising sails like that. Even if it's a couple of inches, it's enough for serious detrimental effect on windward performance. If people don’t know that then they bloody well should. Like I say, they won’t be looking in such wonder at passing Dragonflys, they'd be giving us a run for our money. It wouldn’t surprise me at all if that 2” of stretch amounted to a 10% loss of VMG. Pointing ability and speed are both impacted.
 
Use stainless steel wire as on dinghy halyards.

They care about performance and stretch and often have the jib halyard in particular heaved up to a pretty high tension (above middle C on the piano) in some conditions. And avoiding stuff which is prone to wear through where it goes over a sheave and where it moves under load when sailing (e.g. dyneema).
 
westernman said:
Use stainless steel wire as on dinghy halyards.

They care about performance and stretch and often have the jib halyard in particular heaved up to a pretty high tension (above middle C on the piano) in some conditions. And avoiding stuff which is prone to wear through where it goes over a sheave and where it moves under load when sailing (e.g. dyneema).
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Only vintage dinghies use wire these days. We have a wire luff jib on the X, but a dyneema halyard. The boat was built in 1952. So even the vintage thing is far from universal.
 
Chiara’s slave said:
Some of us don’t treat our cruising sails like that. Even if it's a couple of inches, it's enough for serious detrimental effect on windward performance. If people don’t know that then they bloody well should. Like I say, they won’t be looking in such wonder at passing Dragonflys, they'd be giving us a run for our money. It wouldn’t surprise me at all if that 2” of stretch amounted to a 10% loss of VMG. Pointing ability and speed are both impacted.
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But then we won't be passing as many people! What good is that? (As I said above, I have carbon sails and Dyneema halyards on my tri ... but I wouldn't on an old AWB cruiser.
 
thinwater said:
But then we won't be passing as many people! What good is that? (As I said above, I have carbon sails and Dyneema halyards on my tri ... but I wouldn't on an old AWB cruiser.
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For sure I wouldn’t put my kind of sails on an AWB, but I would make damned sure the sails obeyed the halyard trim. The wrinkles and bags drive me nuts on other peoples boats, let alone my own. Obviously, our sails are similar to yours, carbon/technora, and brand new or nearly so.
 
Chiara’s slave said:
For sure I wouldn’t put my kind of sails on an AWB, but I would make damned sure the sails obeyed the halyard trim. The wrinkles and bags drive me nuts on other peoples boats, let alone my own. Obviously, our sails are similar to yours, carbon/technora, and brand new or nearly so.
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That would make us both obsessive by the average compass!
 
thinwater said:
That would make us both obsessive by the average compass!
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Haha, no carbon here. Lucky to get 4 years out of a set in the tropical sun. A friend is Captain on a 72ft racer cruiser. New North carbon sails every 5 years. Thr main alone is $100,000 US. We went for Vectran this time. They should hold their shape far longer than good quality Dacron.
Friends have just put carbon on their Jen 45 pilothouse. Even they admit its totally unnecessary. They do no more than about 200nm a year
 
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