staysail using luff low torsion rope versus wire stay

[Brion Toss]

Hello,
A sail set on its own luff is not a novelty, any more than luff sag with such sails is. The benefit of stays is that they provide the function of keeping the luff relatively flat, without excessive tension, elasticity, or compression. This leaves the halyard to handle the job -- shared with clew and tack -- of projecting the sail in an efficient shape.
Where loads are lower, and sail fullness is desirable (i.e. off the wind) setting a sail on its own luff can be a good thing, but even then too much load and/or elasticity can be a problem. High modulus fibers don't change any of this; they just give us stronger, lighter tools to work with.
Even if you use a high-modulus rope luff, tied to a high-modulus rope halyard, you are still placing a greatly increased demand on the halyard and its gear (note that the furler swivels, winch, and clutch are not designed for this kind of load, and that the load is roughly doubled on the halyard block),because you are asking the sail and halyard to take on the function of the stay.
So at least for a storm stays'l, keep the stay. Then make it as easy and safe to set and strike as possible. A downhaul, properly rigged and led aft, can allow you to do both jobs from the cockpit; the sail is kept on deck, furled, with the downhaul slip-hitched along its length, until you need to hoist. This is simple, cheap, and utterly reliable.
Fair leads,
Brion Toss

[knuterikt]

Originally Posted by Brion Toss

(note that the furler swivels, winch, and clutch are not designed for this kind of load, and that the load is roughly doubled on the halyard block),because you are asking the sail and halyard to take on the function of the stay.

Seems Facnor have considered this in the sizing guide, numbers for the FX2500 on my 12m LOA boat.

Asymmetric: 90 m2 / 969 ft2
Code 0: 80 m2 / 861 ft2
Staysail: 30 m2 / 322 ft2

The 1:2 halyard for the staysail (solent jib = 26 m2) have the standing end attached to a stay tang while the running part goes over one of the mast head sheaves (via a lead block).

So the load on the winch/clutch/sheave is still acceptable.

The spinnaker halyard block attachment has been strengthened by fitting a new custom designed spinnaker crane (to carry the load from the code 0) and beefed up blocks.
The bowsprit have three positions (fully retracted, half way out and fully extended) and is fitted with an adjustable bob stay.

When we use the Code 0 the bowsprit is set in the half way out position.

The code 0 sets on 1:1 halyard but have an 1:2 adjustable tack line

My storm stays'l is set on a wire stay .

Note on loads:
When we bought this boat the solent jib was on the sail inventory.

The original setup by the PO had a halyard box (where I now have the stay tang) with a 1:1 halyard and a 1:2 tackle at the tack.
The sheave in the halyard box where lost - probably damaged by overloading, so yes there are forces in play here.

I think I can understand why - this is the procedure he described

Dont try this at home

ease the backstay tension
ease the tack
hoist the jib
pull in on the tack (1:2 or was 1:4)
tension the backstay to max

I have never used this extreme procedure (only used the halyard winch on the 1:2 halyard), and have still been able to get a good shape to drive the boat upwind.

[Brion Toss]

Hi again,
Sounds like bases are covered. I'm particularly glad to hear that the storm stays'l is on a stay. No surprise on that sheave; I've seen them crushed, even without the, um, enthusiastic tuning procedure of the previous owner. But I'd still recommend caution, as that 2:1 now gives you god-like power...
Fair leads,
Brion Toss