PS Advisor: 03/03
Rope Lifeline Terminals
You have been a big help with maintaining my Catalina 27. I have been following the articles about lifelines and the reply letters which you have published. I'm glad other people are asking the same questions. I have to replace my lifelines asthey are 20 years old and really stretched. I am considering replacing them with the rope in your article. I was wondering if there is a specific type of hardware you could suggest that I research to help reduce the wear on the rope. I am looking at connecting the rope to the pulpit where there is a small diameter metal loop, and somehow to a pelican hook. Both of these will cause wear points, and I am going to be very careful on how the rope attaches. Any suggestions would be appreciated.
We've received several letters along the same lines. Our instinct would be to use a nylon thimble at the pulpit bail, run the rope lifeline around it, and seize it to itself with standard seizings of sail thread (waxed nylon). No splices, no knots, and it's tidy. It prevents chafe and enables you to see easily if things are failing. If you left a bit of tail at the seizing you could freshen the nip if need be, later on. Then, run the lifeline through the stanchions, put stopper whippings on it at the midships gate to keep it from going slack when the gate is open, and continue across the gate to a pelican hook, either spliced or seized on.
But just for a sanity check, we sent the same question, plus our tentative response, to Brion Toss, rigger extraordinaire. Here's his response:
"Seizings, properly done, are my favorite knots. They can be as strong as any other terminal, at least on wire, and they are extraordinarily simple. Deceptively so, perhaps, as it takes real skill to do them properly. More skill, in my experience, even than splicing. Oh, you can make a seizing that is adequate for some loads by just wrapping real tight, but it would seem that lifelines are a good place for 100% strength.
"Twine seizings are chafe- and UV-vulnerable; however, it's true that one can inspect and replace the seizings before it's a problem.
"Next, high-modulus rope is very compression-sensitive; that's why knots do poorly in it. I haven't done any tests on seized HM rope, covered or uncovered, but it might be a good idea to do some.
"Therefore, if I were to seize lifelines, I would make sure they don't weaken the rope, practice until my seizings were right, make at least two at each end, with no slack leg between the seizings, use a thimble, as you suggest, and cover the seizings with tape or heat-shrink tubing. At which point it would be easier just to splice the things. Core-to-core splices are structurally simpler than for double-braid Dacron. The cover is only there for chafe and UV protection, and they are neat and elegant, with no end hanging out to snag things. Unlike covered wire, the structural core can't corrode away invisibly. The cover is washable and darnable. It's a better tool for the job, and it's easier than doing good seizings.
"I am all for the move to HM rope for lifelines, and I'll repeat that even somewhat gaumy seizings might be adequate. I just wouldn't want to fetch up against one.
"As for tensioning the lifelines, while most of our clients still have—and want—turnbuckles on wire lifelines, I'd rather use lashings on either wire or rope. Lashings are cheap, durable, inspectable, can so easily be stronger than the lifeline, and can even look nice. On the other hand, most lashings one sees in the field are weak and ugly, so I can understand people's reluctance to consider them.
"And this brings up a point: as we move away from wire, throughout the rig, and back into rope, we necessarily move away from machine-made items and back into handwork (i.e. human skill), with which most sailors are a bit out of touch. The high-modulus rope revolution must also be a renaissance in marlingspike arts."
Finally, we checked with Cara Read at Hall Spars. She confirmed that Hall is using both seizings and splices successfully on clients' lifelines.
So... looks as if we all need to go out and start working on our high-tech ropework merit badges.