I've flown my "storm" jib as a cutter stay sail using my spare jib halyard as the stay and the spinnaker halyard to hoist it in the past. This gives an inner fore sail that can be sheeted inside the shrouds. It was quite effective but I wasn't 100% happy with the set up as the Spin halyard was fouled across the forestay. As I have time to think and spend as I wait for access to my boat I've been mulling over this and decided there is a better way.
I'm going to hoist a block spliced into the spare jib halyard and use that to hoist the sail. I've yet to decide how to splice the block into the line but I've just ordered some dyneema to replace the 10 mm braid on braid jib halyard.
6mm 1X19 stainless wire stay breaking load : 2800kg weight per 100m:17.6kg
6mm D-Pro Dyneema breaking load : 4000kg weight per 100m : 2.3kg
10mm braid on braid breaking load: 3000kg weight per 100m : 7.3kg
So I'm replacing a 10mm braid on braid halyard with 6mm Dyneema that is stronger, has less stretch and weighs 1/3rd. And using it as a stay and hoisting point for the inner staysail.
My thoughts are that the weak point now will be the jib sheave which will be subjected to approximately 2X the forces I can wind onto the halyard/stay.
What do you think, am I missing something?
and for anyone interested, Jimmy green just sold me 50 meters of 6mm liras D-pro static for £150 plus tax and shipping which is less than 1/2 normal retail price so if you're after a bargain get in there!!!
Just for interest I carried out a simple experiment and found that a length of braid on braid increased in weight by 50% when I ran it under the tap to stimulate a reasonable rain shower. It was not soaked through. I did this partly because I noted how heavy all the external halyards were when I took them off the mast for the winter. That's perhaps why people have all internal halyards.
A number of Twisters, including me, have an extra inner wire forestay. This normally sits lashed back to the shrouds but can be deployed and fixed to a U bolt aft of the forestay. It's tightened with a rigging screw [with a handle] that fixes to the U bolt with a pelican hook. I have never used the setup in real desperate anger. I should have done so once but survived with a well rolled up genoa.
If you search the Magazine Archive with the term 'inner forestay' you will find three articles.
Yes, the jib does need support. Yes, a quick look at the catalogue tells me you are going to need a substantial block to take the load. I was mystified, last summer, by some bits of plastic on the deck...and then found that the block on the kicking strap had failed. The sheave had collapsed but the rope was still sort of going through the block. So, not a catastrophe.
You might also want to think about chafe on the Dyneema. I'm thinking that this might be the biggest issue.
I'd also note that Twister of Mersea has a set of tracks inboard of the shrouds that are, I much believe, for a small jib for heavy weather windward work.
It's worth a try though.