jack stay/line

[buckborough]

i was wondering if there were any guidance or advice concerning the use of hi-tech line for jack stays or jack lines which are normally fabricated from ss wire or webbing. these are the lines which run along the deck and to which you attach the tether from your harness. the recommended breaking strength for these assemblies varies between 4,000 - 6,000 lbs. the particular application i have in mind would involve tying the line off to a shackle so if i were to go forward with this, i would require a strong no stretch line i could put a knot in. uv resistance and chafe are also concerns. any experience with such application or generic product recommendation would be appreciated. thank you for your kind attention to this question.

[SV Papillon]

The loading issues of jack lines are covered pretty extensively in The riggers apprentice. We used 5/16 12 strand spectra for our jack lines. Running from a dedicated pad eye to the bow sprit base. My only issue, which I guess is why people usually use web, is the round line on deck being a trip hazard. Depending on what your comfortable with running them high and outboard as some people do would alleviate that.

Jake

[Bob Pingel]

Knots in high mod are bad, they really degrade the strength. A better approach is to lash them in place or use hardware.

I have seen some very nice high mod jack lines made of Spectra covered in tubular webbing. The webbing helps with chafe, UV, and roll-under-foot factors.

As Jake said, Brion covers this nicely in TRA, but I believe there is a mathematical error in that section.

Consider a chest high jackline, a bit more practical on a cruising boat....

Good luck,

Bob