Boom options

 In the last few weeks I have been thinking a lot about the sail configuration, and specially the options involving the boom for the main sail.

Tiki wingsails are usually designed without a boom. The wide sheeting base of the catamaran and a full width traveller allow that option. But even so, I think, sailshape is somewhat penalized   The exception is on the Tiki 31, where a loose sprit-style boom is used. When I bought the plans for my mast and sails from Wharram, the loose boom option was recommended.

In the case of Arpex, a boomless mainsail is not an option. I don't like it, and I don't have the wide sheeting base either. So, I need to figure out how to install a boom on the Wingsail. At first  I was thinking towards a wishbone. But conversations with sailmakers indicated that either of them is not sure how it works, specially for reefing. In principle, my preferred option would be the conventional fixed boom with gooseneck. Here, the main challenge is that the wingsail actually slightly turns around the mast, when sailing with beam and aft winds. If the boom is attached firmly to one point, at the gooseneck, a distortion will appear. ...  I would suppose. To avoid this I wonder whether it would be possible to have a gooseneck where the boom would be allowed to follow the movement of the sail. I don't think the picture below shows this well. But It's what I got now. Maybe I will produce another, or produce a mock up. Later might be the best option, since it would also allow to explain to Cleber, my Inox man, who would produce the part.

The other option is to produce a fork-boom, very similar to the gaff. This would certainly be cheaper and quicker to produce. And it could probably be retrofitted with the gooseneck solution, in case the open fork-boom version doesn't work properly.

The other project is about the jib. My plan was to have a salf tacking jib. However, producing the self-tack arrangement seems easyer than it actually is. Also, the sailmaker convinced me to add sailarea, due to our frail winds in Rio. So I decided to go with 100-100% genoa. I found a simple arrangement for the sheeting, which will work fine.