Hammocks and stress on standing rigging

[rhumbunctious]

I see alot of hammocks strung up on decks, attached to the standing rigging (e.g. forestay and shrouds, etc.) and while it's clear that this works, I've been wondering what kind of stress and possible reduction in lifespan this may cause to the rigging. Since the stresses on standing rigging are expected to be along the length of the wire, and the hammock places a bending stress horizontally, what is that doing to the wire? Is it causing or increasing work hardening at the point of stress/bend?

I'm wanting to string a hammock up myself, but am concerned about the long term affects/damage to the rigging.

Should I be worried?

[Auspicious]

I haven't run any numbers but out of concern for local stress on the headstay foil I sling my hammock under the spinnaker pole. It would be nice to hear if I'm over cautious.

[davidsamuelson]

This is not directly related to your question but sort of on the same line.

My awning is tied to my backstay; it is doing exactly what you speak about (a bending stress horizontally). My backstay had an insulator swaged onto the wire right near where the awning is tied. The insulator broke, leaving me without a backstay.

Am I the only person to lose a stay while at the dock?

David

[Douglas]

Gee , David , we would need more info to attribute your backstay swage failure, due to your awning attachment ???

In rigging classes that I have taken with Brion as the instructor, he emphazises (sp-?) avoid "Point Loading" , as it is much better to spread the load .

My awning is also attached onto the back stay and to keep it taught, I have to pull the attached line very hard, so this question concerns me too .

I have hung the whisker pole above the boom and under the awning so some of the awning weight is resting on that pole,,,, but it is still point loading the back stay.

[Ian McColgin]

You can calculate the added tension on the stays from stay length, deflection, weight and what you remember of the parallelogram of force. That's really not going to hurt the stay, but if you go out of your way to make it a sharp bend point curve in the same place every time, that could become an issue. On my schooners - boats with stays unlike my current catboat - I had some sort of halyard along each stay to hold the thing up and I always led lines as far forward and aft to the rail to reduce the stress on the stays, really just for good measure.