Dyneema lifelines

[Zygodactyl]

What diameter dyneema would you choose for lifelines on a 59’ sloop? Anyone using New England Rope STS-12 90 thats coated to reduce UV and chafe?

[bradfordharley]

My experience is that it’s not a strength issue (as the smalller stuff is strong enough) it’s a feel issue. You want something that feels good on the hands and is big enough to lash lines etc to. We went with 5/16 “ and am happy with the hand feel and balance of size and cost. I personally would not go smaller, but that’s just my opinion.

[Dsanduril]

Our boat is 50’, we elected to use 6mm (1/4”). Smaller would be plenty strong, but we chose size based on comfort when grabbing and increased strength after a fair amount of UV exposure.

Haven’t use NE Ropes, our lifelines are SK78. We’ve had them on the boat for about three years, love them.

[JPA Cate]

Our upper lifelines are re-cycled from our old running backstays, 8 mm dyneema. It is way overkill for lifelines, but, it is really comfortable to grab. Our lower ones are 4 mm.

Ann

[hpeer]

Originally Posted by bradfordharley

My experience is that it’s not a strength issue (as the smalller stuff is strong enough) it’s a feel issue. You want something that feels good on the hands and is big enough to lash lines etc to. We went with 5/16 “ and am happy with the hand feel and balance of size and cost. I personally would not go smaller, but that’s just my opinion.

Same for me.

[Tillsbury]

Same here. I used 7mm but if replacing might go 8mm which I'm using for more and more things on the boat.

[Zygodactyl]

Thank you all for your comments. Recommend checking out Blue Wave fittings made by a Danish company specifically for dyneema applications. They are beautifully designed in stainless and aluminum for a variety of diameters and applications.

[slug]

Originally Posted by Zygodactyl

What diameter dyneema would you choose for lifelines on a 59’ sloop? Anyone using New England Rope STS-12 90 thats coated to reduce UV and chafe?

You get rope burns on your ass with fabric lifelines

When fenders and fender boards hang on the fabric they chaff and get locked on

Sails and sheets chafe the fabric

uv burns the fabric to a crisp

Hard to justify fabric lifelines

[Jim Cate]

Originally Posted by slug

You get rope burns on your ass with fabric lifelines

When fenders and fender boards hang on the fabric they chaff and get locked on

Sails and sheets chafe the fabric

uv burns the fabric to a crisp

Hard to justify fabric lifelines

Completely at odds with our experience over the past ~10 years of full time cruising.

NONE of the above have been true for us.

Easy for us to justify dyneema lifelines, hard to justify s/s ones.

Jim

[s/v Jedi]

We switched to Dyneema in 2003 and it was one of the best changes ever. Count on 10-12 year life span (it starts stretching again which is the signal to replace... or when it’s frayed/chafed but wenever had that.

We use 1/4” Samson Amsteel Blue. We splice it to low friction rings on both ends, which we lash to the attachment points with 4mm Spyderline which is a Dyneema with polyester outer braid.

the top lifeline we add a 3/8” polyester outer braid for easy handling

[dannc]

Originally Posted by Zygodactyl

What diameter dyneema would you choose for lifelines on a 59’ sloop? Anyone using New England Rope STS-12 90 thats coated to reduce UV and chafe?

Ran across this website in the last week or so that might be of interest to you:

https://www.colligomarine.com/collig...etic-lifelines

Later,
Dan

[slug]

Originally Posted by Jim Cate

Completely at odds with our experience over the past ~10 years of full time cruising.

NONE of the above have been true for us.

Easy for us to justify dyneema lifelines, hard to justify s/s ones.

Jim

https://www.ussailing.org/wp-content/uploads/2018/01/Dyneema-Spectra-Lifeline-Revision-Jan-2014.pdf

[Jim Cate]

Originally Posted by slug

https://www.ussailing.org/wp-content/uploads/2018/01/Dyneema-Spectra-Lifeline-Revision-Jan-2014.pdf

Thank you for posting that link, Slug, for it supports our experience quite well. Those race folks, who have researched the matter quite thoroughly, seem to think that dyneema lifelines similar to ours are safe and long lived. All one needs to do is use a reasonable diameter line (ours are 8 mm as reported) and be sure that the stanchions don't have sharp edges where the dyneema passes through the ferules... which we, and other cruisers I suspect, automatically did. If this practice is followed, after 10 years the dyneema will still be far stronger than the standard 3/16 inch s/s wire, even if it has not corroded or fatigued and lost strength itself.

Pretty good stuff!

Jim

[slug]

Be sure to tell fellow readers that dyneema may loose up to ten percent of its strength each year from UV

Also tell us how you prevent sheet chafe when jibing the asymmetric and from headsail foot contact

I just replaced s set of dyneema life lines and they looked really bad after 5 plus years

[Jim Cate]

Originally Posted by slug

Be sure to tell fellow readers that dyneema may loose up to ten percent of its strength each year from UV

Also tell us how you prevent sheet chafe when jibing the asymmetric and from headsail foot contact

I just replaced s set of dyneema life lines and they looked really bad after 5 plus years

Aw come on, Slug... that's not what the graph they post shows at all. The two sets of data show 40% to 70 % remaining after TEN years and the decay curves are nearly flat after that. When you start with 8 mm that leaves a very strong remnant, even with the worst case. See the attached graph from that PDF.

And my sheets don't foul the life lines very often, and I take no extraordinary measures to avoid chafe... and yet there isn't devastating chafe seen in reality. And most cruisers don't have deck sweeping genoas and our sails don't chafe the lifelines at all. And should you indeed have such sails, the dyneema life lines won't chafe the sails like s/s wire will, and that's a more serious issue than the reverse IMO.


The race folks mention that the line goes fuzzy after a while, but that it does not significantly reduce strength. Ours are indeed fuzzy but I don't loose sleep over it. Other folks seem to report similar results to mine... I wonder if you just threw away some perfectly good lifelines?.

At any rate, I still find it far easier to justify dyneema than s/s wire for lifelines. You, of course, get to choose for your own boat. And BTW, you have never deigned to tell us what manner of boat you own, and that might help us understand your positions.

Jim