Partially furled staysail on a top-down furler for +30 knot upwind work?

[blue-eyes]

Hi

I want to make a new staysail, talked to a sailmaker today, he said with a staysail on a top-down furler you could partially furl the sail like on your regular furler.

Staysail size is 195 sq ft (18 m2)

I´m not intending to cross oceans, I just S/H a lot.


I had understand with a top-down furler it was either all staysail out or all staysail in, that you could not partially furl a staysail like you could on a regular furler, or does that only apply for asymetric spinnakers which for obvious reasons are by nature impossible to use partially furled?




Reason for using a top-down furler instead of a normal furler for the staysail is the ability to remove it for summer sailing...for tacking the 120% genoa in benign conditions.

Thanks

[fxykty]

There are three types of furlers and you seem to be mixing them up a bit. To clarify, here are the 3 furler types:

1. Regular furler, which requires a permanent forestay, and can be partially furled to reef a sail. Most commonly used for the primary headsail and sometimes for permanent staysails.
2. Bottom-up furler, which is the most common for gennaker and other relatively flat sails and can also be used with headsails and staysails. This kind of furler is generally used with temporary forestays (using a halyard or a high modulus strop). A torque rope sewn into the luff of the sail connects the top and bottom swivels.
3. Top-down furler, which is used with asymmetric spinnakers that have lots of volume up high. As with the bottom-up furler, this kind of furler doesn’t use a permanent forestay. A torque rope connects the top and bottom swivels, independent of the sail’s luff. There is an addition bottom swivel for the sail’s tack.

I have never heard that a top-down furler can be used to partially furl a headsail (nor that a bottom-up furler can be used in that way) - the torque rope is not designed to handle sailing loads trying to unfurl a reefed sail. AFAIK, and a quick perusal of Karver and Facnor websites, any furler not using a permanent stay can only be used for in/out furling and not partially furling (i.e. reefing).

[Loredo]

I have a staysail on a bottom up furler. The furler brand is Ubi Major.
That furler has an incorporated ratchet system that can be set so that it allows to furl the sail but not to unfurl. The staysail (Jib in my case) furls around the anti-torsion rope and thus needs no forestay (fixed or not).

I have used the jib furled several times, works great. I'd do it again anytime. The only "downside" is that for a decent tension on the furler a 2:1 halyard is needed. Makes for a lot of spaghetti in the cokpit.

[bccoast]

Definitely not with a top down furler, well at least with a continuous furling line which I think is mandatory unless you had an electric one. I have a Karver top down furler for my asym gennakers with a continuous furling line. There isnt really anyway to lock it, at least not anything strong enough to lock it while partially unfurled, the weak lock is just so it doesnt open when completely furled in. And even then, have had my entire gennaker blow the lock and open up in 30kt winds. It is pretty challenging to get a tight furl so that it doesn't open half way up in strong winds and you dont want to crank it too tight.

Any furling system with a removable torsion line won't reef. The torsion line will twist and unfurl under load. You need a reefing furler but then isnt removable.

you could just use a smaller sail on top down furler and just unfurl it all the way out and then rely on your sheet angle and tension to adjust twist to spill air as needed.

[fxykty]

Originally Posted by Loredo

I have a staysail on a bottom up furler. The furler brand is Ubi Major.
That furler has an incorporated ratchet system that can be set so that it allows to furl the sail but not to unfurl. The staysail (Jib in my case) furls around the anti-torsion rope and thus needs no forestay (fixed or not).

I have used the jib furled several times, works great. I'd do it again anytime. The only "downside" is that for a decent tension on the furler a 2:1 halyard is needed. Makes for a lot of spaghetti in the cokpit.

What kind of torsion rope are you using? Unless it was specifically designed and engineered for partial furling (AFAIK doesn’t exist), you will destroy the torsion rope. Very curious.

We have a staysail on a NZ Racefurlers bottom up furler system and a 2:1 halyard. The drum is a single line drum (same as most primary furlers) so it could be locked off partially furled, but Doyle, who made the sail and torsion rope say absolutely no partial furling. Heck, even difficult furling times where a winch is needed to furl away a sail needs to be logged for tracking the torsion rope’s age.

We’re on a larger boat so can’t ridiculously up-size our gear without stupid $$$, but I suppose on a smaller boat you could go two sizes up on the recommended torsion rope size?

[Loredo]

What kind of torsion rope? Ehhhh, I have to confess my total ignorance - I have no clue. The sail was build for the scope I've described above and came delivered from North sails in a complete set. Furler + anti torsion rope + sail. They even added markers on the sail how far to furl it for various wind strengths. From memory, up to 20 - up to 35 last one WTSHTF. It's a tri-radial cut in a very heavy laminate cloth. BTW, just to make sure it's clear, it is a continuous line furler. I've used it (furled) several times in 30+ knots of wind, worked like a charm.

[blue-eyes]

Originally Posted by Loredo

What kind of torsion rope? Ehhhh, I have to confess my total ignorance - I have no clue. The sail was build for the scope I've described above and came delivered from North sails in a complete set. Furler + anti torsion rope + sail. They even added markers on the sail how far to furl it for various wind strengths. From memory, up to 20 - up to 35 last one WTSHTF. It's a tri-radial cut in a very heavy laminate cloth. BTW, just to make sure it's clear, it is a continuous line furler. I've used it (furled) several times in 30+ knots of wind, worked like a charm.

Sounds like a very interesting setup

Could you post some photos?

Thanks

[fxykty]

Originally Posted by Loredo

What kind of torsion rope? Ehhhh, I have to confess my total ignorance - I have no clue. The sail was build for the scope I've described above and came delivered from North sails in a complete set. Furler + anti torsion rope + sail. They even added markers on the sail how far to furl it for various wind strengths. From memory, up to 20 - up to 35 last one WTSHTF. It's a tri-radial cut in a very heavy laminate cloth. BTW, just to make sure it's clear, it is a continuous line furler. I've used it (furled) several times in 30+ knots of wind, worked like a charm.

I can’t find this product on any North Sails website. This is a very interesting development and I hope you can post some detailed information or links about your setup.

[Loredo]

This is the furler : https://ubimaioritalia.com/product/21?ubi_pc=1
Sorry, I can't find the English version of the website. Anyhow, the furler is the FR 250 RW, where "RW" stands for Rewind. That's the version of the furler with the ratchet mecanism. Like said before, I don't know what anti-torsion rope has been used. Maybe I can find some indication on the sail / rope itself? I'll check it out.



My boat is on the hard right now. I've not taken any pics of the furler / sail as of yet. It's going to take a while before I can take pics. I'll do once back in the water.

[Benz]

There's lots of new things coming out in torsion cables these days, and everyone seems to have a proprietary cable for their furler system. I recently put ends on a Selden torsion cable that were more like Sta-lock fittings than anything else.
I have a piece of it left in the shop--it's very stiff and heavy, has a core-within-a-core, and maybe some kind of double cover--I'd have to look at it again to describe properly. It was a giant pain the butt, and could only be used with the proprietary Selden ends.

[fxykty]

Originally Posted by Loredo

This is the furler : https://ubimaioritalia.com/product/21?ubi_pc=1
Sorry, I can't find the English version of the website. Anyhow, the furler is the FR 250 RW, where "RW" stands for Rewind. That's the version of the furler with the ratchet mecanism. Like said before, I don't know what anti-torsion rope has been used. Maybe I can find some indication on the sail / rope itself? I'll check it out.



My boat is on the hard right now. I've not taken any pics of the furler / sail as of yet. It's going to take a while before I can take pics. I'll do once back in the water.

The issue isn’t the furler, it’s the torsion cable. North Sails has the Helix system that is a combination of structured luff and torsion cable. https://www.northsails.com/pages/helix Hmmm?

[Loredo]

Nope, not a helix but an anti-torsion cable, that one I'm (almost) sure about.