PDA

View Full Version : High Tech Lifelines?



glythcott
09-12-2008, 12:34 PM
I'd like to begin the discussion of allowing high tech lifelines (eg. Spectra). Various fleets (recently the Express 27) are allowing it. They are certainly strong enough, they are easy to replace and easy to inspect. I'm not sure what the down side(s) is. I'm bring it up now because I have to replace my current wire ones (meat hooks).

George

tiger beetle
09-13-2008, 08:07 AM
I'd like to begin the discussion of allowing high tech lifelines (eg. Spectra). Various fleets (recently the Express 27) are allowing it. They are certainly strong enough, they are easy to replace and easy to inspect. I'm not sure what the down side(s) is. I'm bring it up now because I have to replace my current wire ones (meat hooks).
George

The downside to fiber lifeline material is UV degradation, stretch, and chafe.

I'm not a big fan of fiber lifelines, though they are nice from a cost perspective as it can be less expensive to replace the lifelines and you don't have as many moving parts as wire: no fancy terminations, turnbuckles, clevis pins, and cotter pins. Do you have gates in your lifelines? If so, how do you plan to close them? I've seen some boats using tylaska snap shackles for that purpose.

I've been using 1x19 bare metal lifelines and have not had any problems with meat hooks, and being uncovered, the wire is easy to inspect and clean.

I have not seen any discussion at ISAF or other offshore groups regarding the suitability or trade-offs of replacing stainless with fiber for lifelines. Have any studies been done regarding this?

- rob/beetle

Alchera
09-13-2008, 01:12 PM
ISAF as I understand it requires wire lifelines. For the SSS to modify this requirement, that means someone has to do the research to determine if Spectra or some other material has the necessary properties to make it as safe as wire under extended offshore conditions. Typically, the Transpac race chair doesn't have time for this, and would rather just be able to point to the ISAF. Although it may be true that some one designs fleets are adopting non-wire lifelines, I doubt they have been considered for extended offshore use.

Furthermore, there is no race chair for 2010 yet, so nothing that is said here now is binding upon that person anyway. Also, you are not likely to get a definitive ruling until you actually formally enter. So if you are looking to replace your lifelines now, I would go with wire since you can't count on being granted a waiver at this time or anytime soon.

- Mark/Alchera

Thom
09-15-2008, 03:40 PM
Anyone who has had important gear fail because of poor swages or crevice corrosion or fatigue failure that Stainless is susceptible to but fiber is not will go with the fiber. Granted, line is more susceptible to UV degradation and may stretch slightly more than wire but overall modern line is more safe than stainless (my opinion). To overcome the UV Degradation aspect, the line should be replace periodically if it is uncovered.

Visual inspection of stainless is probably good enough for lifelines...but I no longer trust my rig to stainless swages--had too many failures. Granted, being a trailer sailor means I have much more fatigue stress on my rigging than most.