Friday, April 16, 2021

On building a better rig...

 Killing our mother ocean, a book on my must read list, and in the "No cure for selfish stupidity" department...

Someone recently asked me about my opinions on chainplate materials for his switch to textile rigging. The main part of the question involved whether to use expensive 316 stainless vs the use of much more expensive titanium. When I told him that my choice would be Delrin I'm pretty sure he thought I'd lost my mind.

Now, I'll admit that I'm pretty sensitive to the importance of having a bombproof connection between the rig and the boat and I might be extra careful as I lost a rig to a stainless steel chainplate failure and in the same time period two different friends lost their rigs due to the failure of titanium tangs. So it's a subject that I've given a lot of serious thought to especially where textile rigging is concerned.

A lot of folks now favor the use of carbon fiber or composite chainplates glassed in to the hull which has the advantage of spreading the rigging loads over a much greater area and dispenses with the negative factors of stainless steel and titanium. If I were building a new boat I'd seriously consider this avenue but since the person in question is refitting an existing boat so it's not as easily done and somewhat problematic.

Some time ago, in my ongoing research to make textile rigging more affordable, it occurred to me that if using textile rigging metal chainplates are really sort of a one step forward two steps back kind of thing. You're still using parts that are prone to failure, not exactly textile friendly, and, to add insult to injury, are really quite expensive.

Since the main purpose of a chainplate is to distribute rigging loads on to the hull all we really need to do is to find a more textile friendly way of doing it. 

My first thought, since we're talking "rope", was something akin to a thimble but then realized that any circular or teardrop shapes would be better at distributing the shroud loads to the hull. Better yet the disc or teardrops would not need to be in a metal at all and any high density plastic like Delrin or HDPE would work just fine. The only metal at all in the shroud to hull matrix would be through bolts and backing plates.

The upside is that the plastic chainplates are both inexpensive and easily fabricated by anyone with a DIY bent. The downside is they're not the same old same so if you were to go with the idea I'd factor in that you'd have to do a lot of explaining to passers-by of the less than bright sort. Of course, if you're doing a textile rig you will be having those sort of conversations anyway so not really a factor.

I'm currently writing a more in depth how to on applying some creative frugality to textile rigging design so that anyone can build an inexpensive, user maintainable, and bombproof rig.

More about that soonish.

Listening to Nick Lowe

So it goes...