A Little Sail Info on a Wharram Pahi 63, Please

[Sand crab]

I've noticed that most of these particular boats are gaff rigged and the sails have a luff sleeve(?) that slips all the way around the mast. My questions are:
1. What is the luff sleeve called?
2. How are they installed on the mast? Did I see a full length vertical zipper?
3. Would I be correct in assuming that there would be considerable friction on the mast so uphauling or reefing especially in strong winds might be a bit hectic?
4. I've also seen similar rigs but the sails are attached to the round masts with webbing or rope instead of a sleeve. Is there a particular name for this?
5. Can the gaff be attached to a modern mast track so it can be raised and lowered with the sail?
6. Are the gaffs ever attached permanately at the top of the mast? If so how do you keep it from banging against the mast when the sail is down?
I've checked the Wharram site and Wiki and sail maufacturing sites with no success. I just wanted to know this to broaden my knowlege. Thanks BOB

[tenchiki]

I think they call it an "aero-luff gaff wingsail rig". The gaffs go up and down with the sail, and rotate on the mast. The sail wraps around the mast because it is better aerodynamics. The down side is that you can't put anything on the mast anywhere the sail will go (steps, etc are not possible). As for why do it that way? Think of it as the low-tech version of a square-top sail on a rotating mast -- it has very similar aerodynamics. The only thing with a higher aerodynamic efficiency is a wing sail.
Wharram includes substantial documentation about the whys and reasons for the wingsail when you buy study plans or building plans. I don't find it online in a quick search.
There are some designs where the gaff is permanently attached to the top of the mast (mostly VERY large traditional gaff designs), however Wharram doesn't do it that way, the gaff is attached tot he top of the sail.

[Takamoana]

Hi Sand Crab
Not sure about Tiki 63, but my Tiki30 used the same type of sail. The luff sleeve or pocket has no special name that I am aware of. My sail was zipped with webbing straps every couple of metres for extra strength. Friction was never a problem raising the sail, but in strong winds, a downhaul allowed me to reef or drop the sail with no problems. 4. ?. My gaff was attached to a modified batten car and ran up the mast track. The gaff fits in to a pocket in the head of the sail. The gaff is not permanently attached to the masthead, when we lowered the sail, we would lash it and the gaff into a neat bundle, fit the canvas cover and it would be lashed to the top of the bimini. Hope this is of some use
Gary