Lucky Thomas. David, Slieve and Arne are three true pioneers of the modern junk rig, each with slightly different ideas, and David has probably designed, built and tested more different types (except the SJR!) than anyone. You are surely in good hands.
Thomas, let me add to the pressure you are piling onto Slieve to get those notes updated and completed. That would indeed be a great outcome.
David (and now Arne) – the two different mast heights shown on that drawing - I really must take issue (again). I don’t have much to offer in the way of actual experience (not compared with you guys) but I have rigged a SJR with a mast height equivalent to the lower of the two, which appear as alternatives, and I can state that it won’t work very well. Not with a conventional halyard arrangement and soft mast parrels anyway. If you can fully hoist the sail with that 25-degree halyard angle, without needing a cup of tea and a lie down afterwards – then the next thing you will need is a plethora of extra parrels, of every description, to get the sail to drape properly. That’s not how a SJR should be. Properly tuned, and with a sufficient mast height, nothing more than Slieve’s spanned running parrel-downhauls are needed for the Amiina Mk ll sail for a perfect set. (I take Slieve’s point that they need not be spanned, and I take David’s point that they have not been tested in ocean passage conditions, and that more control might be advisable in that case. But you will get my drift). I increased the mast height on mine – not quite as high as the high one shown as the alternative, in the drawing – but I wish I could. Mine’s only a bit over halfway between. A bit higher would be better, but it made a huge difference to everything.
(I believe that when Amiina was set up, they had an over-size mast and just used it as it was, and if so if would have been a success, and any possible problem arising from a mast too short was quite possibly never thought of, as the problem never arose.)
Arne – interesting that you give credit to Martin and his Custard for solving the “halyard angle issue”. While not wishing to take anything away from Martin, a couple of things crossed my mind immediately. Firstly, I might be wrong, but it looks as though the mast balance of Custard is a bit less than 33% (I might be wrong, we need to check) and also, in the Magazine No. 83 article it states that Martin used ultra short, very slippery mast parrels. Both of these things may be contributing to the solution of that issue.
At some stage I would like to see a discussion about rigid mast parrels, because that's where the answer may properly lie. I think Steve D (Serenity) and Jan Cz with his little boat may have cracked it. (Wingsails and double wishbone aerojunk sails ditto).
And Thomas – whatever type of sail you finally decide on, a photographic diary of the conversion of your boat will be greatly appreciated, both in the magazine and the website archives. I have a feeling it’s going to be pretty good.