Annie Hill wrote:David and I were talking about this topic just before he left. In fact Tystie has a gallows of sorts - a U-shaped structure on the cabin top. He lashes the sail to this at anchor, but the boom doesn't actually rest on it, so this also puts a bending pull at the top of the mast. On Fantail I have no gallows and tie my sail off like Michael mentions. On Badger, it was sufficient simply to haul hard on the sheets to keep the sails quiet at anchor - one of the advantages of a high-aspect ratio rig I guess - and although you could see a wee bend in the masts, it didn't seem to do them any harm. Wood takes a lot of fatiguing and I don't think one should worry too much about it.
To amplify a little:
My upside-down 'U' gallows is smooth on the top, and has eyes underneath the top part of the 'U' where short lines are attached. I can stand in the hatch and tame a wildly thrashing sail bundle by throwing each line in turn over the top, and taking a turn around the gallows tube, tightening and tying eventually, so that there is a line holding the sail bundle securely to port and to starboard. This was an absolute boon on the last passage, when I had to lie a-hull for a few hours in 40 knots, but also when I had to lower the sail to tighten up the bolts at the aft ends of the battens, which were coming loose. I don't think I could have done this with diagonal ties down to deck cleats, the movement would have been too great. I think this is the only way to secure a big, heavy sail bundle, but diagonal lines down to the deck will certainly suffice for smaller rigs. I do not think it at all a good idea to have a gallows with a recess into which you are supposed to drop a wildly thrashing sail bundle at the moment that it passes overhead.
With the wingsails, I had double, port and starboard, sheeting, and this worked well for stabilising the (smaller) sail bundles. Slatting around in a calm was more tolerable with these double sheets.