Installing New Lifelines

[roverhi]

Originally Posted by Stumble

For the cost of 1/4" end fittings for wire lifelines you can make up a set of dyneema ones, and a spare.

Yes, but the only cost for using 'take off' wire lifelines is the cost of the terminals assuming you pirate then out of a riggers junk pile and they'll last practically forever. Dyneema line has a relatively short life span because of UV degradation. Replacement isn't terribly expensive other than the time to do all the splices, however.

[thinwater]

Originally Posted by Stumble

For the cost of 1/4" end fittings for wire lifelines you can make up a set of dyneema ones, and a spare.

Ironically, the only Dyneema lifeline failures I have heard of involved racers that had...

• Used the minimum possible size,
• Hiked HARD around the course, and
• Previously used bare SS lifeline.

The bare line created burrs in the stanchions that cut the Dyneema.


The moral of the story is to use larger Dyneema than strictly required (still very light and economical) and properly prepare the stanchions.

[Stumble]

Originally Posted by roverhi

Yes, but the only cost for using 'take off' wire lifelines is the cost of the terminals assuming you pirate then out of a riggers junk pile and they'll last practically forever. Dyneema line has a relatively short life span because of UV degradation. Replacement isn't terribly expensive other than the time to do all the splices, however.

My lifelines are now 7 years old in New Orleans, and used about $150 of line. They have been exposed to the elements since day one.

A Johnson pelican hook (you need four) for 1/4 wire is $50. So just for the hooks you are at twice the price of my entire set up. Four 1/4" turnbuckles and swags are another $200. So your cheap way costs about $400. Or you can go with $150 worth of 1/4 dyneema.


While I am planning on replacing the line soon, it isn't because they are really in need, just the wife wants another color.

[roverhi]

Don't want to argue you with Greg but the lifelines on my old boat didn't cost more than yours. For one, don't believe in gates, they are disasters waiting to happens only needed four terminals for each set of lifelines. On boats that have had gates, like the current one, seldom if ever used the 'feature'. Lifting a leg over the lines was a hell of a lot safer and easier than trying to find something to grab on to when the gate was down when the lifeline wasn't there. The pelican hooks were/are a pain to use though admittedly don't have the fancy Johnson pelican hooks which do work way better. Incidentally, Johnson does make the fancy pelican hooks and a lot of other nifty fittings for splicing into Dyneema life lines but then your 'cheap' set up ain't so cheap anymore. You can't argue that the synthetics aren't degraded by UV. For rigging, Colligo seems to think it's 6 years. Oversize lifelines can probably go more than that. Maybe even double the life expectancy but they will have to be changed out because of UV degradation way before 1x19 wire would.

Will probably go with Dyneema when I redo the ugly, filthy, POS coated lifelines that I inherited with my current boat. That's only because I live at the end of the world in Konaand not exactly a sailing mecca so finding takeoff used wire probably will never happen here. In any case, I'm sailing into my 70th decade so don't really have to worry about outliving the Dyneema.

[ka4wja]

Peter,
Can you tell me more about Dynemma having poor UV-resistance, as all I've found (from the manufacturers and dealers) is that it has very good UV-resistance...(the reason I ask is that I was planning on going with Dyneema lifelines, as my replacements, and just did some research earlier this summer...)

Originally Posted by roverhi

Dyneema line has a relatively short life span because of UV degradation.

Originally Posted by roverhi

You can't argue that the synthetics aren't degraded by UV. For rigging, Colligo seems to think it's 6 years.

The sources I've looked at (Dyneema manufacturer Marlow, etc.) say that Dyneema is very uv resistant....

UV Resistant: Dyneema® has very good resistance to photo degradation, maintaining its performance when exposed to UV light

Dyneema

http://www.marlowropes.com/technical...roperties.html

http://www.samsonrope.com/Pages/Prod...?ProductID=872

http://www.pelicanrope.com/pdfs2010/...eet_UHMWPE.pdf

MaterialUV Ranking (5=highest, 1=lowest)

Polyester 5

HMPE (Dyneema®) 5

Nylon (UV treated) 4

Aramids (Technora®, Nomex®, Kevlar®, Twaron®) 3

Vectran® 3

Polypropylene 2

Zylon® 1

Several patented variations of this fiber have slightly different characteristics, but Spectra-Dyneema-HMPE has the highest strength-to-weight ratio, low stretch, and impressive maximum working loads. Very slippery with good hand, but poor knot-holding ability and a low melting point (300°F). Does not absorb water, but it will experience gradual “creep” or permanent elongation under sustained static load. Dyneema is a good core upgrade from polyester double braid, with almost no stretch.
Often used uncovered, or with a polyester cover where it encounters a cleat or the drum of a winch. Great in multi-part purchase systems, or for replacing 7 x 19 wire in trapeze lines. A very popular line with excellent longevity; it is also light, so it floats.
Newest, strongest, lowest stretch, and with nearly zero creep are Dyneema lines made from a variant called SK-90. It stretches 10-15% less than the most common type of Dyneema, SK-75, and is also 10-15% stronger. New England Ropes’ STS-12 SK-90 and Dinghy Star (from FSE Robline) are two ropes made with this fiber

Trying to avoid some confusion here....perhaps Colligo Marine was referring to something other than Dyneema???


John
s/v Annie Laurie

[roverhi]

Colligo uses Dynax Dux. It's a proprietary form of Dyneema that has lower stretch and other characteristics that make it better for rigging. I wouldn't worry about Dyneema falling apart in a week or two in the sun. Will probably go more than 10 years or more as lifelines just not virtually forever as for SS 1x19 wire. With the high tensile loads of rigging, Colligo is being conservative in putting a 6 year life on it that may be motivated as much by their lawyers as an actual fail by date.

In order of preference, 1/4" 1x19 would be my first choice especially if I didn't have to buy it. The terminals are a significant expense so are a factor. 2nd would be Dyneema. Last and really not a consideration would be plastic coated SS wire.

[Glenn.Brooks]

So far, don't see anyone mentioning turning the ends of Dyneema or other line around an eye. Just looping Dyneema or other synthetic will reduce its strength over half. So riggers and suppliers generally recommend using a 5:1 diameter eye to maintain full strength of the line at each end-particularity if you clip onto pelican hooks. Example: 1-4" DuX line or similar should be wrapped around a 1 1/4" eye. This makes it easy to tie off or shackle the line to what ever stanchion or fitting the life line connects to.


Sent from my iPad using Cruisers Sailing Forum

[thinwater]

Originally Posted by Glenn.Brooks

So far, don't see anyone mentioning turning the ends of Dyneema or other line around an eye. Just looping Dyneema or other synthetic will reduce its strength over half. So riggers and suppliers generally recommend using a 5:1 diameter eye to maintain full strength of the line at each end-particularity if you clip onto pelican hooks. Example: 1-4" DuX line or similar should be wrapped around a 1 1/4" eye. This makes it easy to tie off or shackle the line to what ever stanchion or fitting the life line connects to.

Sent from my iPad using Cruisers Sailing Forum

No. In fact single braids do much better than most lines around a turn, not seeing any reduction until R=0.5. The reason is that the line flattens (looks a lot like webbing when loaded up), and that there are 2 ends carrying the load. Put another way, there is a 50% reduction, but since there are 2 legs, that does not matter.

Dux is different, as it does not deform in the same way without considerable strength loss.

Not sayin' you don't need to watch for sharp corners.

And if you think your pulpit will hold anything beyond ~ 1500 pounds it will be very unusual. Most will crumple below 1000 pounds.

(Based on US Naval Academy testing, Sampson data, and personal break testing.)