Oh?
Hi Matt,
I respectfully disagree. While it is true that fiber lifelines can chafe at stanchions, this is a matter of sharp stanchions; reduce the edges, and the chafe goes away. Otherwise, the logic would dictate that you also dispense with rope halyards if the sheaves had sharp edges, instead of fixing those sheaves.
Note too that wire lifelines, at least covered ones, often fail at sharp-edged stanchions, because of corrosion that starts where the cover has been chafed away. We have Spectra lifelines all over the world now, with no problems, once chafe spots have been eliminated.
UV is a non-issue, partly because it slows down dramatically as the surface fibers oxidize, partly because proper-size HM lifelines are so overwhelmingly overbuilt. Wire lifelines, on the other hand, fatigue and corrode, and do so much faster in warm, salty climates.
As for the "huge cost differences", wha'? Wire coated to 1/4" is about the same as 1/4" Spectra, once you figure terminals in, and less if you dispense with turnbuckles. We use round bronze sail thimbles for ours, and lash them with Spiderline. Now, if you go with 1/8" "cheese slicer" uncoated wire, you can save some money, but heaven help you if you ever land on those things. Fatter wire, scaled to reduce bruising, is still not pleasant to land on. And the price goes up.
Oh, and by the way, constant monitoring of any lifeline is not a bad thing; the difference with rope is that you can actually see when it is getting dangerous. Wire, on the other hand, is inherently secretive about its condition, which is why sudden failures are so common with it.
For the above reasons, we simply won't install wire lifelines any more. On the other hand, rope lifelines require more from the installer -- you have to make sure there are no chafe points, that the splices and lashings are good, that all constructional stretch is out. Wire you can just bang out and move on. Not a compelling argument for me.
Fair leads,
Brion Toss
PS,
Getting back to the original question, I'd use smaller Spectra, or perhaps that Spiderline, for the netting. A couple of turns at the lifeline, to spread the load and prevent motion, will prevent any chance of chafe.
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