Carbon Fiber Gaff

[kimsails]

This is a question for John Harris on building a carbon fiber gaff.

I was talking to a friend who works with carbon fiber and I showed him the Pocketship gaff. He asked me about fittings that would be fixed to the spar. No problem as they are on the drawings. He asked me how "loaded" this gaff would be. Told him I don't have a clue.

So John, can you tell me what the "load" is on the gaff??? Thanks.

Kim

[kimsails]

Hi, John. Is there a way I can figure this out or estimate it Thanks.

Kim

[John C. Harris]

"So John, can you tell me what the "load" is on the gaff??? Thanks."

Sure, it's 2.075 quasi-joules. You can plug that number into any of the sailboat gaff-design software packages and it'll generate the design. I think there's an iPhone app for that.

Kidding! kidding!

There's lots and lots of load on a PocketShip gaff, which is why it's rather heavy rendered in wood. As I've written here before, I've a mind to experiment with a lighter one. Eliminating the stainless T-track on the gaff and substituting a shipshape lashing of some sort would probably produce a noticeable improvement. I was going to go one step further and build a hollow wooden gaff. Thin-walled, with the carbon on the inside so it's still varnished wood on the outside to look pretty at shows. I actually made some sketches of how to do this, but I've been too busy to follow up on it. The drawings are too sketchy to be of much use to anyone not residing inside my cobwebby brain, alas.

I don't mean to be glib but someone with sufficient technical proficiency to execute a carbon gaff could probably eyeball the published scantlings of the wooden gaff and hack a carbon substitute without much drama. Remember the performance sailor's rule: if a spar never breaks, you've built it too heavy.

Having just finished building the 31-foot carbon mast for Madness-the-proa, I can report that A) I hate carbon fiber more than ever and B) it really is hellish tricky to work with.

[Bflat]

I'm intrigued with the suggestion to lash the sail to the gaff, thus eliminating its sail track for weight reduction. It seems like an elegant solution. Is there a downside?

BTW, this is my first post. I've been lurking for a while and plan to build.

Thanks in advance,
Bob