Why we don’t want an A-Frame mainsheet system on our catamaran
In our previous video, we looked at the mainsheet track and traveller system used on the Gunboat 68. If you haven’t seen this blog post and video you can find the link here.
In our opinion, the mainsheet traveller system on the Gunboat is far superior to an A-Frame system. For starters, it is simple to use. You can set your mainsail leech profile and then adjust the traveller to trim the main by either using push button control or manually adjusting the winches in the cockpit. You can use the traveller to power up or de-power your boat without losing efficiency in your sail. It is also much safer as you have the ability to drop sheets quickly and effectively should the need arise. We believe this to be the ultimate mainsheet set up for any multihull.
On our Catana catamaran, we have an A-Frame system. This double-ended dead eye system is popular on a lot of older French boat designs. Although it is a cheaper system to install, it gives limited control and can be quite dangerous.
This is of course a topic in which there is room for debate. If you would like to chime in on the discussion then feel free to comment on our forum via this link.
If you want to know more about how these two mainsheet systems work, we suggest checking out this great article by Schionning Design https://schionningdesign.com/wp-content/uploads/2020/09/Mainsheet-Systems-for-Catamarans-Schionning-Designs.pdf
I hear you on the drawback of not being able to dump one sheet and get as much ease as you’d like — one thought is that the deadend of each sheet could terminate on either a fitting on the boom that would be released with a dump or could enter the boom and run forward to a block inside the boom that could be dumped. In the first case you would get ease of at least six or seven feet of sheet if you set it up with a stopper knot so it couldn’t pull through the deck block when dumped and would still allow the main to be pulled back in although with fewer parts in the purchases. In the latter case you could get more dump and also could use the dump to trim in both sheets simultaneously. Just a thought. FWIW I have a traveler on my Atlantic 55 and am totally happy to have it 😉